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High shear stress induces atherosclerotic vulnerable plaque formation through angiogenesis.
Wang, Yi; Qiu, Juhui; Luo, Shisui; Xie, Xiang; Zheng, Yiming; Zhang, Kang; Ye, Zhiyi; Liu, Wanqian; Gregersen, Hans; Wang, Guixue
Rupture of atherosclerotic plaques causing thrombosis is the main cause of acute coronary syndrome and ischemic strokes. Inhibition of thrombosis is one of the important tasks developing biomedical materials such as intravascular stents and vascular grafts. Shear stress (SS) influences the formation and development of atherosclerosis. The current review focuses on the vulnerable plaques observed in the high shear stress (HSS) regions, which localizes at the proximal region of the plaque intruding into the lumen. The vascular outward remodelling occurs in the HSS region for vascular compensation and that angiogenesis is a critical factor for HSS which induces atherosclerotic vulnerable plaque formation. These results greatly challenge the established belief that low shear stress is important for expansive remodelling, which provides a new perspective for preventing the transition of stable plaques to high-risk atherosclerotic lesions. PMID:27482467
Effect of atorvastatin therapy on oxidant-antioxidant status and atherosclerotic plaque formation
Sezer ED; Sozmen EY; Nart D; Onat T
Ebru Demirel Sezer1, Eser Yildirim Sozmen1, Deniz Nart2, Taner Onat11Medical Biochemistry, 2Pathology Department, Ege University School of Medicine, Izmir, TurkeyBackground: The aim of this study was to determine the oxidant–antioxidant status and lipid peroxidation products, as well as paraoxonase and atherosclerotic plaque formation, in a hypercholesterolemic atherosclerosis rabbit model to investigate the effects of atorvastatin in the atherosclerotic process.Methods: Forty male ...
Piperlongumine inhibits atherosclerotic plaque formation and vascular smooth muscle cell proliferation by suppressing PDGF receptor signaling
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Son, Dong Ju [Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA (United States); Division of Cardiology, Department of Medicine, Emory University, Atlanta, GA (United States); Kim, Soo Yeon [Division of Life Science, Korea Basic Science Institute, Daejeon (Korea, Republic of); Han, Seong Su [University of Iowa Carver College of Medicine, Department of Pathology, Iowa City, IA (United States); Kim, Chan Woo [Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA (United States); Division of Cardiology, Department of Medicine, Emory University, Atlanta, GA (United States); Department of Bioinspired Science, Ehwa Womans University, Seoul (Korea, Republic of); Kumar, Sandeep [Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA (United States); Division of Cardiology, Department of Medicine, Emory University, Atlanta, GA (United States); Park, Byeoung Soo [Nanotoxtech Co., Ansan (Korea, Republic of); Lee, Sung Eun [Division of Applied Biology and Chemistry, Kyungpook National University, Daegu (Korea, Republic of); Yun, Yeo Pyo [College of Pharmacy, Chungbuk National University, Cheongju (Korea, Republic of); Jo, Hanjoong, E-mail: email@example.com [Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA (United States); Division of Cardiology, Department of Medicine, Emory University, Atlanta, GA (United States); Department of Bioinspired Science, Ehwa Womans University, Seoul (Korea, Republic of); Park, Young Hyun, E-mail: email@example.com [Department of Food Science and Nutrition, College of Natural Sciences, Soonchunhyang University, Asan (Korea, Republic of)
Highlights: Black-Right-Pointing-Pointer Anti-atherogenic effect of PL was examined using partial carotid ligation model in ApoE KO mice. Black-Right-Pointing-Pointer PL prevented atherosclerotic plaque development, VSMCs proliferation, and NF-{kappa}B activation. Black-Right-Pointing-Pointer Piperlongumine reduced vascular smooth muscle cell activation through PDGF-R{beta} and NF-{kappa}B-signaling. Black-Right-Pointing-Pointer PL may serve as a new therapeutic molecule for atherosclerosis treatment. -- Abstract: Piperlongumine (piplartine, PL) is an alkaloid found in the long pepper (Piper longum L.) and has well-documented anti-platelet aggregation, anti-inflammatory, and anti-cancer properties; however, the role of PL in prevention of atherosclerosis is unknown. We evaluated the anti-atherosclerotic potential of PL in an in vivo murine model of accelerated atherosclerosis and defined its mechanism of action in aortic vascular smooth muscle cells (VSMCs) in vitro. Local treatment with PL significantly reduced atherosclerotic plaque formation as well as proliferation and nuclear factor-kappa B (NF-{kappa}B) activation in an in vivo setting. PL treatment in VSMCs in vitro showed inhibition of migration and platelet-derived growth factor BB (PDGF-BB)-induced proliferation to the in vivo findings. We further identified that PL inhibited PDGF-BB-induced PDGF receptor beta activation and suppressed downstream signaling molecules such as phospholipase C{gamma}1, extracellular signal-regulated kinases 1 and 2 and Akt. Lastly, PL significantly attenuated activation of NF-{kappa}B-a downstream transcriptional regulator in PDGF receptor signaling, in response to PDGF-BB stimulation. In conclusion, our findings demonstrate a novel, therapeutic mechanism by which PL suppresses atherosclerosis plaque formation in vivo.
Piperlongumine inhibits atherosclerotic plaque formation and vascular smooth muscle cell proliferation by suppressing PDGF receptor signaling
International Nuclear Information System (INIS)
Highlights: ► Anti-atherogenic effect of PL was examined using partial carotid ligation model in ApoE KO mice. ► PL prevented atherosclerotic plaque development, VSMCs proliferation, and NF-κB activation. ► Piperlongumine reduced vascular smooth muscle cell activation through PDGF-Rβ and NF-κB-signaling. ► PL may serve as a new therapeutic molecule for atherosclerosis treatment. -- Abstract: Piperlongumine (piplartine, PL) is an alkaloid found in the long pepper (Piper longum L.) and has well-documented anti-platelet aggregation, anti-inflammatory, and anti-cancer properties; however, the role of PL in prevention of atherosclerosis is unknown. We evaluated the anti-atherosclerotic potential of PL in an in vivo murine model of accelerated atherosclerosis and defined its mechanism of action in aortic vascular smooth muscle cells (VSMCs) in vitro. Local treatment with PL significantly reduced atherosclerotic plaque formation as well as proliferation and nuclear factor-kappa B (NF-κB) activation in an in vivo setting. PL treatment in VSMCs in vitro showed inhibition of migration and platelet-derived growth factor BB (PDGF-BB)-induced proliferation to the in vivo findings. We further identified that PL inhibited PDGF-BB-induced PDGF receptor beta activation and suppressed downstream signaling molecules such as phospholipase Cγ1, extracellular signal-regulated kinases 1 and 2 and Akt. Lastly, PL significantly attenuated activation of NF-κB—a downstream transcriptional regulator in PDGF receptor signaling, in response to PDGF-BB stimulation. In conclusion, our findings demonstrate a novel, therapeutic mechanism by which PL suppresses atherosclerosis plaque formation in vivo.
Effect of atorvastatin therapy on oxidant-antioxidant status and atherosclerotic plaque formation
Directory of Open Access Journals (Sweden)
Sezer ED
Full Text Available Ebru Demirel Sezer1, Eser Yildirim Sozmen1, Deniz Nart2, Taner Onat11Medical Biochemistry, 2Pathology Department, Ege University School of Medicine, Izmir, TurkeyBackground: The aim of this study was to determine the oxidant–antioxidant status and lipid peroxidation products, as well as paraoxonase and atherosclerotic plaque formation, in a hypercholesterolemic atherosclerosis rabbit model to investigate the effects of atorvastatin in the atherosclerotic process.Methods: Forty male New Zealand rabbits were divided into four groups, ie, a control group receiving standard pellets, a group receiving atorvastatin therapy, a hypercholesterolemic group receiving an atherogenic diet, and a group receiving both an atherogenic diet and atorvastatin.Results: The atherogenic diet increased the levels of low-density lipoprotein (LDL thiobarbituric acid reactive substances (1.84 vs 3.79 nmol/mg protein and LDL-conjugated diene (147 vs 318 µmol/mg protein after induction of oxidation by Cu2+, despite an increase of superoxide dismutase activity. Treatment with atorvastatin limited LDL oxidation significantly (LDL thiobarbituric acid reactive substances 2.19 nmol/mg protein, LDL-conjugated diene 222 µmol/mg protein. Paraoxonase, which prevents LDL oxidation and inactivates LDL-derived oxidized phospholipids, showed a pronounced decrease in the group receiving the atherogenic diet (110 U/L to 28 U/L, and atorvastatin treatment increased paraoxonase activity. Histological examination of arcus aorta tissues from the hypercholesterolemic group showed abundant plaque formation surrounding and obstructing the lumen, whereas treatment with atorvastatin prevented or limited plaque formation, keeping the plaque thin and localized.Conclusion: Atorvastatin has dramatic antiatherosclerotic effects, part of which seems to be due to the antioxidant features of the parent drug and/or its metabolites, favoring inhibition of LDL oxidation.Keywords: atherosclerosis
MRI of the transplanted endothelial progenitor cells for prevent atherosclerotic plaque formation
International Nuclear Information System (INIS)
Objective: To evaluate the 1.5 T magnetic resonance imaging system to depict and track in vivo of magnetically labeled endothelial progenitor cells (EPCs), and to study the possibility for preventing the atherosclerotic plaque formation in New Zealand rabbit model of carotid arterial injury after transplantation. Methods: New Zealand rabbit EPCs were isolated, confirmed, expanded and then incubated with home synthesized Fe2O3-PLL, Prussian blue stain was performed for showing intracellular irons. The model of carotid arterial injury was performed by 2.5F balloons, the group A of 8 rabbits received magnetically labeled EPCs, group B of 3 rabbits received fluorescent-labeled EPCs and the group C of 5 rabbits were given same volume saline injection after endothelial injury of the carotid artery. MR imaging and histology were performed and compared 4 days later for randomly chosen three rabbit, each from one of the three group; all the other rabbits were fed with high lipid diet and examed using MR imaging and histology after 15 weeks. Results: Epcs labeling efficiency was more than 95% by Prussian blue stain, 4 days after transplantation of EPCs, only in group A, the injured endothelium of carotid artery had signal intensity loss in T2*WI, which were correlated well with the area where the most Prussian blue staining positive cells were found in histopathology analyses. The rabbits of group A and B which received EPCs transplantation exhibited fewer plaques formation than those of the group C (P2O3-PLL. The 1.5 T magnetic resonance imaging system could depict and monitor the magnetically labeled endothelial progenitor cells homing to the injured endothelium of the artery, and EPCs contribute to preventing atherosclerotic plaque formation in New Zealand rabbit model of atherosclerosis. (authors)
Platelet activation and platelet-monocyte aggregate formation by the atherosclerotic plaque lipid lysophosphatidic acid
Haserück, Nadine
Oxidized LDL and platelets play a central role in the pathogenesis of atherosclerosis and ischemic cardiovascular diseases. Lysophosphatidic acid (LPA) is a thrombogenic substance that accumulates in mildly-oxidized LDL and in human atherosclerotic lesions, and is responsible for the initial platelet activation, shape change, induced by mildly-oxidized LDL and extracts of lipid-rich atherosclerotic plaques (Siess et al., 1999 Proc Natl Acad Sci USA 1999). LPA directly induced platelet shape c...
Effect of Quercus infectoria and Rosa damascena on lipid profile and atherosclerotic plaque formation in rabbit model of hyperlipidemia.
Gholamhoseinian, A; Shahouzehi, B; Joukar, S; Iranpoor, M
Hyperlipidemia is the cause of many complications in the human societies. In this study, the effect of methanol extracts of Quercus infectoria (QI) galls and Rosa damascena (RD) Mill flower were studied on lipid profile and atherosclerotic plaques formation in hyperlipidemic rabbits. Thirty-six New Zeland white rabbits randomly divided into 6 groups as control (I), hyperlipidemic (II), hyperlipidemic+QI (III), hyperlipidemic+RD (IV), +Atorvastolin (V) and hyperlipidemic+Orlistat (VI) and were fed with high fat diet (0.5% cholesterol and 16% hydrogenated vegetable oil) for 45 days. At the end of the study period, lipid profile and plaque formation were assessed. Total Cholesterol (TC), Low Density Lipoprotein (LDL) and Triglyceride (TG) levels were significantly increased in hyperlipidemic group compared with control group (p Quercus infectoria significantly decreased plasma levels of TC, TG and LDL (p < 0.001). It also decreased plaques formation in semi lunar valve and thoracic aorta. Rosa damascena mill flower methanol extract moderately decreased the levels of TC, TG, LDL and plaques formation but it was not significant. HDL levels and weight of animals did not show significant difference among groups. Based on the doses used in this study, our finding indicated that QI but no RD methanol extract has anti atherogenic and hypolipidemic activities. PMID:22530439
Ultrasound Tissue Characterization of Vulnerable Atherosclerotic Plaque
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Eugenio Picano
Full Text Available A thrombotic occlusion of the vessel fed by ruptured coronary atherosclerotic plaque may result in unstable angina, myocardial infarction or death, whereas embolization from a plaque in carotid arteries may result in transient ischemic attack or stroke. The atherosclerotic plaque prone to such clinical events is termed high-risk or vulnerable plaque, and its identification in humans before it becomes symptomatic has been elusive to date. Ultrasonic tissue characterization of the atherosclerotic plaque is possible with different techniques—such as vascular, transesophageal, and intravascular ultrasound—on a variety of arterial segments, including carotid, aorta, and coronary districts. The image analysis can be based on visual, video-densitometric or radiofrequency methods and identifies three distinct textural patterns: hypo-echoic (corresponding to lipid- and hemorrhage-rich plaque, iso- or moderately hyper-echoic (fibrotic or fibro-fatty plaque, and markedly hyperechoic with shadowing (calcific plaque. Hypoechoic or dishomogeneous plaques, with spotty microcalcification and large plaque burden, with plaque neovascularization and surface irregularities by contrast-enhanced ultrasound, are more prone to clinical complications than hyperechoic, extensively calcified, homogeneous plaques with limited plaque burden, smooth luminal plaque surface and absence of neovascularization. Plaque ultrasound morphology is important, along with plaque geometry, in determining the atherosclerotic prognostic burden in the individual patient. New quantitative methods beyond backscatter (to include speed of sound, attenuation, strain, temperature, and high order statistics are under development to evaluate vascular tissues. Although not yet ready for widespread clinical use, tissue characterization is listed by the American Society of Echocardiography roadmap to 2020 as one of the most promising fields of application in cardiovascular ultrasound imaging
Nuclear Molecular Imaging for Vulnerable Atherosclerotic Plaques
Lee, Soo Jin; Paeng, Jin Chul
Atherosclerosis is an inflammatory disease as well as a lipid disorder. Atherosclerotic plaque formed in vessel walls may cause ischemia, and the rupture of vulnerable plaque may result in fatal events, like myocardial infarction or stroke. Because morphological imaging has limitations in diagnosing vulnerable plaque, molecular imaging has been developed, in particular, the use of nuclear imaging probes. Molecular imaging targets various aspects of vulnerable plaque, such as inflammatory cell...
Piperlongumine inhibits atherosclerotic plaque formation and vascular smooth muscle cell proliferation by suppressing PDGF receptor signaling
Son, Dong Ju; Kim, Soo Yeon; Han, Seong Su; Kim, Chan Woo; Kumar, Sandeep; Park, Byeoung Soo; Lee, Sung Eun; Yun, Yeo Pyo; Jo, Hanjoong; Park, Young Hyun
Piperlongumine (piplartine, PL) is an alkaloid found in the long pepper (Piper longum L.) and has well-documented anti-platelet aggregation, anti-inflammatory, and anti-cancer properties; however, the role of PL in prevention of atherosclerosis is unknown. We evaluated the anti-atherosclerotic potential of PL in an in vivo murine model of accelerated atherosclerosis and defined its mechanism of action in aortic vascular smooth muscle cells (VSMCs) in vitro. Local treatment with PL significant...
Imaging Atherosclerotic Plaque Calcification: Translating Biology.
Bailey, Grant; Meadows, Judith; Morrison, Alan R
Calcification of atherosclerotic lesions was long thought to be an age - related, passive process, but increasingly data has revealed that atherosclerotic calcification is a more active process, involving complex signaling pathways and bone-like genetic programs. Initially, imaging of atherosclerotic calcification was limited to gross assessment of calcium burden, which is associated with total atherosclerotic burden and risk of cardiovascular mortality and of all cause mortality. More recently, sophisticated molecular imaging studies of the various processes involved in calcification have begun to elucidate information about plaque calcium composition and consequent vulnerability to rupture, leading to hard cardiovascular events like myocardial infarction. As such, there has been renewed interest in imaging calcification to advance risk assessment accuracy in an evolving era of precision medicine. Here we summarize recent advances in our understanding of the biologic process of atherosclerotic calcification as well as some of the molecular imaging tools used to assess it. PMID:27339750
Chemokine Receptor 7 Knockout Attenuates Atherosclerotic Plaque Development
Luchtefeld, Maren; Grothusen, Christina; Gagalick, Andreas; Jagavelu, Kumaravelu; Schuett, Harald; Tietge, Uwe J. F.; Pabst, Oliver; Grote, Karsten; Drexler, Helmut; Foerster, Reinhold; Schieffer, Bernhard
Background-Atherosclerosis is a systemic inflammatory disease characterized by the formation of atherosclerotic plaques. Both innate immunity and adaptive immunity contribute to atherogenesis, but the mode of interaction is poorly understood. Chemokine receptor 7 (CCR7) is critically involved in the
Hyperspectral imaging of atherosclerotic plaques in vitro
Larsen, Eivind L. P.; Randeberg, Lise L.; Olstad, Elisabeth; Haugen, Olav A.; Aksnes, Astrid; Svaasand, Lars O.
Vulnerable plaques constitute a risk for serious heart problems, and are difficult to identify using existing methods. Hyperspectral imaging combines spectral- and spatial information, providing new possibilities for precise optical characterization of atherosclerotic lesions. Hyperspectral data were collected from excised aorta samples (n = 11) using both white-light and ultraviolet illumination. Single lesions (n = 42) were chosen for further investigation, and classified according to histological findings. The corresponding hyperspectral images were characterized using statistical image analysis tools (minimum noise fraction, K-means clustering, principal component analysis) and evaluation of reflectance/fluorescence spectra. Image analysis combined with histology revealed the complexity and heterogeneity of aortic plaques. Plaque features such as lipids and calcifications could be identified from the hyperspectral images. Most of the advanced lesions had a central region surrounded by an outer rim or shoulder-region of the plaque, which is considered a weak spot in vulnerable lesions. These features could be identified in both the white-light and fluorescence data. Hyperspectral imaging was shown to be a promising tool for detection and characterization of advanced atherosclerotic plaques in vitro. Hyperspectral imaging provides more diagnostic information about the heterogeneity of the lesions than conventional single point spectroscopic measurements.
Electrochemical Impedance Spectroscopy to Characterize Inflammatory Atherosclerotic Plaques
Yu, Fei; Dai, Xiaohu; Beebe, Tyler; Hsiai, Tzung
Despite advances in diagnosis and therapy, atherosclerotic cardiovascular disease remains the leading cause of morbidity and mortality in the Western world. Predicting metabolically active atherosclerotic lesions has remained an unmet clinical need. We hereby developed an electrochemical strategy to characterize the inflammatory states of high-risk atherosclerotic plaques. Using the concentric bipolar microelectrodes, we sought to demonstrate distinct Electrochemical Impedance Spectroscopic (...
Multimodality imaging of carotid atherosclerotic plaque: Going beyond stenosis
Divyata Hingwala; Chandrasekharan Kesavadas; Sylaja, Padmavathy N; Bejoy Thomas; Tirur Raman Kapilamoorthy
Apart from the degree of stenosis, the morphology of carotid atherosclerotic plaques and presence of neovascularization are important factors that may help to evaluate the risk and ′vulnerability′ of plaques and may also influence the choice of treatment. In this article, we aim to describe the techniques and imaging findings on CTA, high resolution MRI and contrast enhanced ultrasound in the evaluation of carotid atherosclerotic plaques. We also discuss a few representative cases from our in...
Atherosclerosis and Atheroma Plaque Rupture: Imaging Modalities in the Visualization of Vasa Vasorum and Atherosclerotic Plaques
Invasive angiography has been widely accepted as the gold standard to diagnose cardiovascular pathologies. Despite its superior resolution of demonstrating atherosclerotic plaque in terms of degree of lumen stenosis, the morphological assessment for the plaque is insufficient for the analysis of plaque components, and therefore, unable to predict the risk status or vulnerability of atherosclerotic plaque. There is an increased body of evidence to show that the vasa vasorum play an important r...
Gene expression and 18FDG uptake in atherosclerotic carotid plaques
DEFF Research Database (Denmark)
Pedersen, Sune Folke; Græbe, Martin; Hag, Anne Mette Fisker;
PURPOSE: Metabolic assessment of vascular inflammation by 2-[F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG)-PET is a promising new approach for the evaluation of the vulnerability of atherosclerotic plaques. Quantitative real-time PCR allows measurement of gene expression of markers...... of atherosclerotic plaque vulnerability. These techniques were applied in advanced atherosclerotic disease to relate metabolism and inflammatory activity to the gene expression profile of the vulnerable atherosclerotic plaque. METHODS: Seventeen patients with clinical symptoms of cerebral vascular...... subsequently recovered by carotid endarterectomy. The gene expression of markers of vulnerability - CD68, IL-18, matrix metalloproteinase 9, cathepsin K, GLUT-1, and hexokinase type II (HK2) - were measured in plaques by quantitative PCR. RESULTS: In a multivariate linear regression model, GLUT-1, CD68...
Ultrafast laser ablation for targeted atherosclerotic plaque removal
Lanvin, Thomas; Conkey, Donald B.; Descloux, Laurent; Frobert, Aurelien; Valentin, Jeremy; Goy, Jean-Jacques; Cook, Stéphane; Giraud, Marie-Noelle; Psaltis, Demetri
Coronary artery disease, the main cause of heart disease, develops as immune cells and lipids accumulate into plaques within the coronary arterial wall. As a plaque grows, the tissue layer (fibrous cap) separating it from the blood flow becomes thinner and increasingly susceptible to rupturing and causing a potentially lethal thrombosis. The stabilization and/or treatment of atherosclerotic plaque is required to prevent rupturing and remains an unsolved medical problem. Here we show for the first time targeted, subsurface ablation of atherosclerotic plaque using ultrafast laser pulses. Excised atherosclerotic mouse aortas were ablated with ultrafast near-infrared (NIR) laser pulses. The physical damage was characterized with histological sections of the ablated atherosclerotic arteries from six different mice. The ultrafast ablation system was integrated with optical coherence tomography (OCT) imaging for plaque-specific targeting and monitoring of the resulting ablation volume. We find that ultrafast ablation of plaque just below the surface is possible without causing damage to the fibrous cap, which indicates the potential use of ultrafast ablation for subsurface atherosclerotic plaque removal. We further demonstrate ex vivo subsurface ablation of a plaque volume through a catheter device with the high-energy ultrafast pulse delivered via hollow-core photonic crystal fiber.
Coronary perivascular adipose tissue characteristics are related to atherosclerotic plaque size and composition : A post-mortem study
Verhagen, Sandra N.; Vink, Aryan; van der Graaf, Yolanda; Visseren, Frank L. J.
Background: Perivascular adipose tissue (pvAT) may influence atherosclerotic plaque formation. We aim to determine the association between the local amount and inflammatory properties of pvAT and the size and composition of atherosclerotic plaque in the left anterior descending artery (LAD). Methods
In silico analyses of metagenomes from human atherosclerotic plaque samples
DEFF Research Database (Denmark)
Mitra, Suparna; Drautz-Moses, Daniela I; Alhede, Morten;
microbes isolated from human atherosclerotic vessels. However, high-resolution investigation of microbial infectious agents from human vessels that may contribute to atherosclerosis is very limited. In spite of the progress in recent sequencing technologies, analyzing host-associated metagenomes remain...... a challenge. RESULTS: To investigate microbiome diversity within human atherosclerotic tissue samples, we employed high-throughput metagenomic analysis on: (1) atherosclerotic plaques obtained from a group of patients who underwent endarterectomy due to recent transient cerebral ischemia or stroke. (2...
Genesis and growth of extracellular-vesicle-derived microcalcification in atherosclerotic plaques
Hutcheson, Joshua D.; Goettsch, Claudia; Bertazzo, Sergio; Maldonado, Natalia; Ruiz, Jessica L.; Goh, Wilson; Yabusaki, Katsumi; Faits, Tyler; Bouten, Carlijn; Franck, Gregory; Quillard, Thibaut; Libby, Peter; Aikawa, Masanori; Weinbaum, Sheldon; Aikawa, Elena
Clinical evidence links arterial calcification and cardiovascular risk. Finite-element modelling of the stress distribution within atherosclerotic plaques has suggested that subcellular microcalcifications in the fibrous cap may promote material failure of the plaque, but that large calcifications can stabilize it. Yet the physicochemical mechanisms underlying such mineral formation and growth in atheromata remain unknown. Here, by using three-dimensional collagen hydrogels that mimic structural features of the atherosclerotic fibrous cap, and high-resolution microscopic and spectroscopic analyses of both the hydrogels and of calcified human plaques, we demonstrate that calcific mineral formation and maturation results from a series of events involving the aggregation of calcifying extracellular vesicles, and the formation of microcalcifications and ultimately large calcification areas. We also show that calcification morphology and the plaque's collagen content--two determinants of atherosclerotic plaque stability--are interlinked.
Atherosclerosis and Atheroma Plaque Rupture: Imaging Modalities in the Visualization of Vasa Vasorum and Atherosclerotic Plaques
Directory of Open Access Journals (Sweden)
Zhonghua Sun
Full Text Available Invasive angiography has been widely accepted as the gold standard to diagnose cardiovascular pathologies. Despite its superior resolution of demonstrating atherosclerotic plaque in terms of degree of lumen stenosis, the morphological assessment for the plaque is insufficient for the analysis of plaque components, and therefore, unable to predict the risk status or vulnerability of atherosclerotic plaque. There is an increased body of evidence to show that the vasa vasorum play an important role in the initiation, progression, and complications of atherosclerotic plaque leading to major adverse cardiac events. This paper provides an overview of the evidence-based reviews of various imaging modalities with regard to their potential value for comprehensive characterization of the composition, burden, and neovascularization of atherosclerotic plaque.
Atherosclerosis and atheroma plaque rupture: imaging modalities in the visualization of vasa vasorum and atherosclerotic plaques.
Sun, Zhonghua
Invasive angiography has been widely accepted as the gold standard to diagnose cardiovascular pathologies. Despite its superior resolution of demonstrating atherosclerotic plaque in terms of degree of lumen stenosis, the morphological assessment for the plaque is insufficient for the analysis of plaque components, and therefore, unable to predict the risk status or vulnerability of atherosclerotic plaque. There is an increased body of evidence to show that the vasa vasorum play an important role in the initiation, progression, and complications of atherosclerotic plaque leading to major adverse cardiac events. This paper provides an overview of the evidence-based reviews of various imaging modalities with regard to their potential value for comprehensive characterization of the composition, burden, and neovascularization of atherosclerotic plaque. PMID:24688380
Multimodality imaging of carotid atherosclerotic plaque: Going beyond stenosis
Hingwala, Divyata; Kesavadas, Chandrasekharan; Sylaja, Padmavathy N; Thomas, Bejoy; Kapilamoorthy, Tirur Raman
Apart from the degree of stenosis, the morphology of carotid atherosclerotic plaques and presence of neovascularization are important factors that may help to evaluate the risk and 'vulnerability' of plaques and may also influence the choice of treatment. In this article, we aim to describe the techniques and imaging findings on CTA, high resolution MRI and contrast enhanced ultrasound in the evaluation of carotid atherosclerotic plaques. We also discuss a few representative cases from our institute with the related clinical implications. PMID:23986615
Multimodality imaging of carotid atherosclerotic plaque: Going beyond stenosis
Directory of Open Access Journals (Sweden)
Divyata Hingwala
Full Text Available Apart from the degree of stenosis, the morphology of carotid atherosclerotic plaques and presence of neovascularization are important factors that may help to evaluate the risk and ′vulnerability′ of plaques and may also influence the choice of treatment. In this article, we aim to describe the techniques and imaging findings on CTA, high resolution MRI and contrast enhanced ultrasound in the evaluation of carotid atherosclerotic plaques. We also discuss a few representative cases from our institute with the related clinical implications.
Tensile and compressive properties of fresh human carotid atherosclerotic plaques.
LENUS (Irish Health Repository)
Maher, Eoghan
Accurate characterisation of the mechanical properties of human atherosclerotic plaque is important for our understanding of the role of vascular mechanics in the development and treatment of atherosclerosis. The majority of previous studies investigating the mechanical properties of human plaque are based on tests of plaque tissue removed following autopsy. This study aims to characterise the mechanical behaviour of fresh human carotid plaques removed during endarterectomy and tested within 2h. A total of 50 radial compressive and 17 circumferential tensile uniaxial tests were performed on samples taken from 14 carotid plaques. The clinical classification of each plaque, as determined by duplex ultrasound is also reported. Plaques were classified as calcified, mixed or echolucent. Experimental data indicated that plaques were highly inhomogeneous; with variations seen in the mechanical properties of plaque obtained from individual donors and between donors. The mean behaviour of samples for each classification indicated that calcified plaques had the stiffest response, while echolucent plaques were the least stiff. Results also indicated that there may be a difference in behaviour of samples taken from different anatomical locations (common, internal and external carotid), however the large variability indicates that more testing is needed to reach significant conclusions. This work represents a step towards a better understanding of the in vivo mechanical behaviour of human atherosclerotic plaque.
Autophagy in Atherosclerosis: A Phenomenon Found in Human Carotid Atherosclerotic Plaques
Institute of Scientific and Technical Information of China (English)
Huihui Liu; Yongjun Cao; Tong Tong; Jijun Shi; Yanlin Zhang; Yaping Yang; Chunfeng Liu
Background:Autophagy has been found to be involved in animal and cell models ofatherosclerosis,but to date,it lacks general observation in human atherosclerotic plaques.Here,we investigated autophagy in smooth muscle cells (SMCs),endothelial cells (ECs),and macrophages in human atherosclerotic plaques via transmission electron microscopy (TEM),western blotting,and immunohistochemistry analysis.Methods:The histopathologic morphology of these plaques was observed via hematoxylin and eosin staining.The ultrastructural morphology of the SMCs,ECs,and macrophages in these plaques was observed via TEM.The localization ofmicrotubule-associated protein 1 light chain 3 (MAP 1-LC3),a relatively special maker ofautophagy,in plaques was observed by double fluorescent immunochemistty and western blotting.Results:All of these human atherosclerotic plaques were considered advanced and unstable in histologically observation.By double fluorescent immunochemistry,the expression of LC3-Ⅱ increased in the SMCs of the fibrous cap,the macrophages,and the microvascular ECs of the plaque shoulders.The protein level of LC3-Ⅱ by western blotting significantly increased in plaques compared with normal controls.In addition,TEM observation of plaques revealed certain features of autophagy in SMCs,ECs,and macrophages including the formation of myelin figures,vacuolization,and the accumulation of inclusions in the cytosol.These results indicate that autophagy is activated in SMCs,ECs,and macrophages in human advanced atherosclerotic plaques.Conclusions:Our study is to demonstrate the existence of autophagy in human atherosclerotic plaques by different methods,which may contribute to the development of pharmacological approaches to stabilize vulnerable and rupture-prone lesions.
Atherosclerotic Plaque Destabilization in Mice: A Comparative Study.
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Helene Hartwig
Full Text Available Atherosclerosis-associated diseases are the main cause of mortality and morbidity in western societies. The progression of atherosclerosis is a dynamic process evolving from early to advanced lesions that may become rupture-prone vulnerable plaques. Acute coronary syndromes are the clinical manifestation of life-threatening thrombotic events associated with high-risk vulnerable plaques. Hyperlipidemic mouse models have been extensively used in studying the mechanisms controlling initiation and progression of atherosclerosis. However, the understanding of mechanisms leading to atherosclerotic plaque destabilization has been hampered by the lack of proper animal models mimicking this process. Although various mouse models generate atherosclerotic plaques with histological features of human advanced lesions, a consensus model to study atherosclerotic plaque destabilization is still lacking. Hence, we studied the degree and features of plaque vulnerability in different mouse models of atherosclerotic plaque destabilization and find that the model based on the placement of a shear stress modifier in combination with hypercholesterolemia represent with high incidence the most human like lesions compared to the other models.
Imaging Modalities to Identity Inflammation in an Atherosclerotic Plaque
International Nuclear Information System (INIS)
Atherosclerosis is a chronic, progressive, multifocal arterial wall disease caused by local and systemic inflammation responsible for major cardiovascular complications such as myocardial infarction and stroke. With the recent understanding that vulnerable plaque erosion and rupture, with subsequent thrombosis, rather than luminal stenosis, is the underlying cause of acute ischemic events, there has been a shift of focus to understand the mechanisms that make an atherosclerotic plaque unstable or vulnerable to rupture. The presence of inflammation in the atherosclerotic plaque has been considered as one of the initial events which convert a stable plaque into an unstable and vulnerable plaque. This paper systemically reviews the noninvasive and invasive imaging modalities that are currently available to detect this inflammatory process, at least in the intermediate stages, and discusses the ongoing studies that will help us to better understand and identify it at the molecular level
Evaluation of recombinant endostatin in the treatment of atherosclerotic plaques and neovascularization in rabbits*
Mao, Wei; Kong, Jing; Dai, Jin; Huang, Zhao-quan; Wang, Dong-zhi; Ni, Gui-bao; Chen, Min-Li
Objective: Atherosclerotic plaques and neovascularization play an important role in the course of coronary atherosclerosis. This study evaluated the effect of recombinant endostatin on experimental atherosclerotic plaques and neovascularization in rabbits. Methods: Eighteen healthy male rabbits were divided into three groups: control group, atherosclerotic model group, and recombinant endostatin treated group. The atherosclerotic model was established via a high-cholesterol diet after balloon...
Spectral CT of carotid atherosclerotic plaque: comparison with histology
International Nuclear Information System (INIS)
To distinguish components of vulnerable atherosclerotic plaque by imaging their energy response using spectral CT and comparing images with histology. After spectroscopic calibration using phantoms of plaque surrogates, excised human carotid atherosclerotic plaques were imaged using MARS CT using a photon-processing detector with a silicon sensor layer and microfocus X-ray tube (50 kVp, 0.5 mA) at 38-μm voxel size. The plaques were imaged, sectioned and re-imaged using four threshold energies: 10, 16, 22 and 28 keV; then sequentially stained with modified Von Kossa, Perl's Prussian blue and Oil-Red O, and photographed. Relative Hounsfield units across the energies were entered into a linear algebraic material decomposition model to identify the unknown plaque components. Lipid, calcium, iron and water-like components of plaque have distinguishable energy responses to X-ray, visible on spectral CT images. CT images of the plaque surface correlated very well with histological photographs. Calcium deposits (>1,000 μm) in plaque are larger than iron deposits (<100 μm), but could not be distinguished from each other within the same voxel using the energy range available. Spectral CT displays energy information in image form at high spatial resolution, enhancing the intrinsic contrast of lipid, calcium and iron within atheroma. (orig.)
Atherosclerotic plaque detection by confocal Brillouin and Raman microscopies
Meng, Zhaokai; Basagaoglu, Berkay; Yakovlev, Vladislav V.
Atherosclerosis, the development of intraluminal plaque, is a fundamental pathology of cardiovascular system and remains the leading cause of morbidity and mortality worldwide. Biomechanical in nature, plaque rupture occurs when the mechanical properties of the plaque, related to the morphology and viscoelastic properties, are compromised, resulting in intraluminal thrombosis and reduction of coronary blood flow. In this report, we describe the first simultaneous application of confocal Brillouin and Raman microscopies to ex-vivo aortic wall samples. Such a non-invasive, high specific approach allows revealing a direct relationship between the biochemical and mechanical properties of atherosclerotic tissue.
Adiponectin-coated nanoparticles for enhanced imaging of atherosclerotic plaques
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Almer G
Full Text Available Gunter Almer1,6, Karin Wernig2, Matthias Saba-Lepek3, Samih Haj-Yahya1, Johannes Rattenberger4, Julian Wagner4, Kerstin Gradauer3, Daniela Frascione3, Georg Pabst3, Gerd Leitinger5, Harald Mangge1, Andreas Zimmer2, Ruth Prassl31Clinical Institute of Medical and Chemical Laboratory Diagnostics, 2Institute of Pharmaceutical Sciences, Department of Pharmaceutical Technology, University of Graz, 3Institute of Biophysics and Nanosystems Research, Austrian Academy of Science, 4Institute for Electron Microscopy and Fine Structure Research, Graz University of Technology, 5Institute of Cell Biology, Histology and Embryology, Medical University of Graz, 6Center for Medical Research, Medical University of Graz, AustriaBackground: Atherosclerosis is a leading cause of mortality in the Western world, and plaque diagnosis is still a challenge in cardiovascular medicine. The main focus of this study was to make atherosclerotic plaques visible using targeted nanoparticles for improved imaging. Today various biomarkers are known to be involved in the pathophysiologic scenario of atherosclerotic plaques. One promising new candidate is the globular domain of the adipocytokine adiponectin (gAd, which was used as a targeting sequence in this study.Methods: gAd was coupled to two different types of nanoparticles, namely protamine-oligonucleotide nanoparticles, known as proticles, and sterically stabilized liposomes. Both gAd-targeted nanoparticles were investigated for their potency to characterize critical scenarios within early and advanced atherosclerotic plaque lesions using an atherosclerotic mouse model. Aortic tissue from wild type and apolipoprotein E-deficient mice, both fed a high-fat diet, were stained with either fluorescent-labeled gAd or gAd-coupled nanoparticles. Ex vivo imaging was performed using confocal laser scanning microscopy.Results: gAd-targeted sterically stabilized liposomes generated a strong signal by accumulating at the surface of
Rosiglitazone modulates collagen deposition and metabolism in atherosclerotic plaques of fat-fed ApoE-knockout mice
Zhou, Mingxue; Xu, Hao; Liu, Weihong; Liu, Hongxu
Abnormal collagen deposition, as well as collagen metabolism, plays a crucial role in the formation and progression of vulnerable atherosclerotic plaques (VAPs), which are susceptible to rupture. According to our previous findings, rosiglitazone, a thiazolidinedione, can promote the stability of atherosclerotic plaques in fat-fed ApoE-knockout mice; however, it is unknown whether it can modulate collagen deposition and metabolism in VAPs. The present study was designed to determine the effect...
Directional spatial frequency analysis of lipid distribution in atherosclerotic plaque
Korn, Clyde; Reese, Eric; Shi, Lingyan; Alfano, Robert; Russell, Stewart
Atherosclerosis is characterized by the growth of fibrous plaques due to the retention of cholesterol and lipids within the artery wall, which can lead to vessel occlusion and cardiac events. One way to evaluate arterial disease is to quantify the amount of lipid present in these plaques, since a higher disease burden is characterized by a higher concentration of lipid. Although therapeutic stimulation of reverse cholesterol transport to reduce cholesterol deposits in plaque has not produced significant results, this may be due to current image analysis methods which use averaging techniques to calculate the total amount of lipid in the plaque without regard to spatial distribution, thereby discarding information that may have significance in marking response to therapy. Here we use Directional Fourier Spatial Frequency (DFSF) analysis to generate a characteristic spatial frequency spectrum for atherosclerotic plaques from C57 Black 6 mice both treated and untreated with a cholesterol scavenging nanoparticle. We then use the Cauchy product of these spectra to classify the images with a support vector machine (SVM). Our results indicate that treated plaque can be distinguished from untreated plaque using this method, where no difference is seen using the spatial averaging method. This work has the potential to increase the effectiveness of current in-vivo methods of plaque detection that also use averaging methods, such as laser speckle imaging and Raman spectroscopy.
In-vivo Attenuation and Equivalent Scatterer size parameters for Atherosclerotic Carotid Plaque: Preliminary Results
Shi, Hairong; Varghese, Tomy; Mitchell, Carol C; McCormick, Matthew; Dempsey, Robert J; Kliewer, Mark A.
We have previously reported on the equivalent scatterer size, attenuation coefficient, and axial strain properties of atherosclerotic plaque ex-vivo. Since plaque structure and composition may be damaged during a carotid endarterectomy procedure, characterization of in-vivo properties of atherosclerotic plaque is essential. The relatively shallow depth of the carotid artery and plaque enables non-invasive evaluation of carotid plaque utilizing high frequency linear array transducers. We inves...
Imaging of atherosclerotic plaques by optical coherence tomography (OCT)
Perree, Jop; van Leeuwen, Ton G. J. M.; Pasterkamp, Gerard; Izatt, Joseph A.
Optical Coherence Tomography (OCT) is an imaging technique that measures the intensity of light back scattered from sub- surface tissue structures with a very high resolution. This report describes the qualitative and quantitative correlation of OCT and histology measurements for plaque presence and thickness of caps overlying atherosclerotic plaques, respectively. Imaging of samples (n equals 12) was performed from the luminal side with 1300 nm 1 mW or 10 mW light sources, with coherence lengths of 21 and 16 micrometer, respectively. Samples were histologically processed and stained with H&E, EvG and picro-sirius red (PSR) and histological and OCT images were matched. For each sample, the presence of plaque was assessed and the minimal cap thickness was measured by means of histomorphometry and OCT. We found a sensitivity of 6/6 and a specificity of 5/6 for detection of plaques with OCT. Quantitative analysis showed a strong and significant correlation between OCT and histology cap thickness measurements (R2 equals 0.968). Thus, OCT is a sensitive method for detection of plaques, is quantitatively comparable to histology and holds promise as a high-resolution diagnostic tool for visualization of plaque cap thickness.
Atherosclerotic geometries exacerbate pathological thrombus formation poststenosis in a von Willebrand factor-dependent manner
Westein, Erik; Meer, van der Andries D.; Kuijpers, Marijke J.E.; Frimat, Jean-Philippe; Berg, van den Albert; Heemskerk, Johan W.M.
Rupture of a vulnerable atherosclerotic plaque causes thrombus formation and precipitates cardiovascular diseases. In addition to the thrombogenic content of a plaque, also the hemodynamic microenvironment plays a major role in thrombus formation. How the altered hemodynamics around a plaque promote
Morphological study of atherosclerotic plaque and its application in vulnerability evaluation
Institute of Scientific and Technical Information of China (English)
The relationships between the morphological characteristics and the vulnerability of atherosclerotic plaque were analyzed theoretically and several suggestions were proposed to evaluate the plaque vulnerability. Validated by animal experiments and clinical studies, the theoretical results were confirmed.
Increased ADRP expression in human atherosclerotic lesions correlates with plaque instability
Xu, Bin; Zhao, Huiying; Wang, Shengnan; Sun, Xiwei; Qin, Xiujiao
Adipose differentiation-related protein (ADRP) is intrinsically associated with the surface of lipid droplets implicated in the development of atherosclerosis. We analyzed expression of ADRP in human popliteal artery plaques. Atherosclerotic plaque tissue from the popliteal artery was obtained from 18 patients undergoing lower extremity amputation for arteriosclerosis obliterans, and with either stable (n = 6) or unstable (n = 12) atherosclerotic plaques. Plaques were histologically classifie...
Phage display identification of CD100 in human atherosclerotic plaque macrophages and foam cells.
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Maria Carolina Aquino Luque
Full Text Available Atherosclerosis is a complex disease in which vessels develop plaques comprising dysfunctional endothelium, monocyte derived lipid laden foam cells and activated lymphocytes. Considering that humans and animal models of the disease develop quite distinct plaques, we used human plaques to search for proteins that could be used as markers of human atheromas. Phage display peptide libraries were probed to fresh human carotid plaques, and a bound phage homologous to plexin B1, a high affinity receptor for CD100, was identified. CD100 is a member of the semaphorin family expressed by most hematopoietic cells and particularly by activated T cells. CD100 expression was analyzed in human plaques and normal samples. CD100 mRNA and protein were analyzed in cultured monocytes, macrophages and foam cells. The effects of CD100 in oxLDL-induced foam cell formation and in CD36 mRNA abundance were evaluated. Human atherosclerotic plaques showed strong labeling of CD100/SEMA4D. CD100 expression was further demonstrated in peripheral blood monocytes and in in vitro differentiated macrophages and foam cells, with diminished CD100 transcript along the differentiation of these cells. Incubation of macrophages with CD100 led to a reduction in oxLDL-induced foam cell formation probably through a decrease of CD36 expression, suggesting for the first time an atheroprotective role for CD100 in the human disease. Given its differential expression in the numerous foam cells and macrophages of the plaques and its capacity to decrease oxLDL engulfment by macrophages we propose that CD100 may have a role in atherosclerotic plaque development, and may possibly be employed in targeted treatments of these atheromas.
Monocytes/macrophages activation contributes to b-gamma-glutamyltransferase accumulation inside atherosclerotic plaques
Belcastro, Eugenia; Franzini, Maria; Cianchetti, Silvana; Lorenzini, Evelina; Masotti, Silvia; Fierabracci, Vanna; Pucci, Angela; Pompella, Alfonso; Corti, Alessandro
Background Gamma-glutamyltransferase (GGT) is a well-established independent risk factor for cardiovascular mortality related to atherosclerotic disease. Four GGT fractions have been identified in plasma, but only b-GGT fraction accumulates in atherosclerotic plaques, and correlates with other histological markers of vulnerability. The present study was aimed to evaluate whether macrophagic lineage cells may provide a source of b-GGT within the atherosclerotic plaque. Methods GGT expression a...
Data Mining of Atherosclerotic Plaque Transcriptomes Predicts STAT1-Dependent Inflammatory Signal Integration in Vascular Disease
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Krzysztof Sikorski
Full Text Available Atherosclerotic plaque development involves multiple extra- and intra-cellular signals engaging cells from the immune system and from the vasculature. Pro-inflammatory pathways activated by interferon gamma (IFNγ and toll-like receptor 4 (TLR4 ligands are profoundly involved in plaque formation and have been shown to involve cross-talk in all atheroma-interacting cell types leading to increased activation of signal transducer and activator of transcription-1 (STAT1 and elevated expression of pro-inflammatory mediators. Here we demonstrate that in Gene Expression Omnibus repository (GEO deposited microarray datasets, obtained from human coronary and carotid atherosclerotic plaques, a significant increase in expression of pro-inflammatory and immunomodulatory genes can be detected. Moreover, increased expression of multiple chemokines, adhesion molecules and matrix-remodeling molecules was commonly detected in both plaque types and correlated with the presence of putative STAT1 binding sites in their promoters, suggesting strong involvement of STAT1 in plaque development. We also provide evidence to suggest that STAT1-nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB or STAT1-interferon-regulated factor (IRF regulatory modules are over-represented in the promoters of these inflammatory genes, which points to a possible contribution of IFNγ and TLR4 cross-talk in the process of atherogenesis. Finally, a subset of these genes encodes for secreted proteins that could serve as a basis of a non-invasive diagnostic assay. The results of our in silico analysis in vitro provide potential evidence that STAT1-dependent IFNγ-TLR4 cross-talk plays a crucial role in coronary and carotid artery plaque development and identifies a STAT1-dependent gene signature that could represent a novel diagnostic tool to monitor and diagnose plaque progression in human atherosclerosis.
IL-19 Halts Progression of Atherosclerotic Plaque, Polarizes, and Increases Cholesterol Uptake and Efflux in Macrophages.
Gabunia, Khatuna; Ellison, Stephen; Kelemen, Sheri; Kako, Farah; Cornwell, William D; Rogers, Thomas J; Datta, Prasun K; Ouimet, Mireille; Moore, Kathryn J; Autieri, Michael V
Atherosclerosis regression is an important clinical goal, and treatments that can reverse atherosclerotic plaque formation are actively being sought. Our aim was to determine whether administration of exogenous IL-19, a Th2 cytokine, could attenuate progression of preformed atherosclerotic plaque and to identify molecular mechanisms. LDLR(-/-) mice were fed a Western diet for 12 weeks, then administered rIL-19 or phosphate-buffered saline concomitant with Western diet for an additional 8 weeks. Analysis of atherosclerosis burden showed that IL-19-treated mice were similar to baseline, in contrast to control mice which showed a 54% increase in plaque, suggesting that IL-19 halted the progression of atherosclerosis. Plaque characterization showed that IL-19-treated mice had key features of atherosclerosis regression, including a reduction in macrophage content and an enrichment in markers of M2 macrophages. Mechanistic studies revealed that IL-19 promotes the activation of key pathways leading to M2 macrophage polarization, including STAT3, STAT6, Kruppel-like factor 4, and peroxisome proliferator-activated receptor γ, and can reduce cytokine-induced inflammation in vivo. We identified a novel role for IL-19 in regulating macrophage lipid metabolism through peroxisome proliferator-activated receptor γ-dependent regulation of scavenger receptor-mediated cholesterol uptake and ABCA1-mediated cholesterol efflux. These data show that IL-19 can halt progression of preformed atherosclerotic plaques by regulating both macrophage inflammation and cholesterol homeostasis and implicate IL-19 as a link between inflammation and macrophage cholesterol metabolism. PMID:26952642
Atherosclerotic plaque component segmentation in combined carotid MRI and CTA data incorporating class label uncertainty
Engelen, Arna; Niessen, Wiro; Klein, Stefan; Groen, Harald; Verhagen, Hence; Wentzel, Jolanda; van der Lugt, Aad; de Bruijne, Marleen
textabstractAtherosclerotic plaque composition can indicate plaque vulnerability. We segment atherosclerotic plaque components from the carotid artery on a combination of in vivo MRI and CT-angiography (CTA) data using supervised voxelwise classification. In contrast to previous studies the ground truth for training is directly obtained from 3D registration with histology for fibrous and lipid-rich necrotic tissue, and with μCT for calcification. This registration does, however, not provide a...
Atherosclerotic Plaque Component Segmentation in Combined Carotid MRI and CTA Data Incorporating Class Label Uncertainty
van Engelen, A.; Niessen, W.J.; Klein, S.; Groen, H. C.; Verhagen, H. J. M.; Wentzel, J.J.; van der Lugt, A.; De Bruijne, M.
Atherosclerotic plaque composition can indicate plaque vulnerability. We segment atherosclerotic plaque components from the carotid artery on a combination of in vivo MRI and CT-angiography (CTA) data using supervised voxelwise classification. In contrast to previous studies the ground truth for training is directly obtained from 3D registration with histology for fibrous and lipid-rich necrotic tissue, and with CT for calcification. This registration does, however, not provide accurate voxel...
Atherosclerotic plaque component segmentation in combined carotid MRI and CTA data incorporating class label uncertainty
Atherosclerotic plaque composition can indicate plaque vulnerability. We segment atherosclerotic plaque components from the carotid artery on a combination of in vivo MRI and CT-angiography (CTA) data using supervised voxelwise classification. In contrast to previous studies the ground truth for training is directly obtained from 3D registration with histology for fibrous and lipid-rich necrotic tissue, and with [Formula: see text]CT for calcification. This registration does, however, not pro...
Optical detection of structural changes in human carotid atherosclerotic plaque
Korol, R. M.; Canham, P. B.; Finlay, H. M.; Hammond, R. R.; Quantz, M.; Ferguson, G. G.; Liu, L. Y.; Lucas, A. R.
Background: Arterial bifurcations are commonly the sites of developing atherosclerotic plaque that lead to arterial occlusions and plaque rupture (myocardial infarctions and strokes). Laser induced fluorescence (LIF) spectroscopy provides an effective nondestructive method supplying spectral information on extracellular matrix (ECM) protein composition, specifically collagen and elastin. Purpose: To investigate regional differences in the ECM proteins -- collagen I, III and elastin in unstable plaque by analyzing data from laser-induced fluorescence spectroscopy of human carotid endarterectomy specimens. Methods: Gels of ECM protein extracts (elastin, collagen types I & III) were measured as reference spectra and internal thoracic artery segments (extra tissue from bypass surgery) were used as tissue controls. Arterial segments and the endarterectomy specimens (n=21) were cut into 5mm cross-sectional rings. Ten fluorescence spectra per sampling area were then recorded at 5 sites per ring with argon laser excitation (357nm) with a penetration depth of 200 μm. Spectra were normalized to maximum intensity and analyzed using multiple regression analysis. Tissue rings were fixed in formalin (within 3 hours of surgery), sectioned and stained with H&E or Movat's Pentachrome for histological analysis. Spectroscopy data were correlated with immunohistology (staining for elastin, collagen types I, III and IV). Results: Quantitative fluorescence for the thoracic arteries revealed a dominant elastin component on the luminal side -- confirmed with immunohistology and known artery structure. Carotid endarterectomy specimens by comparison had a significant decrease in elastin signature and increased collagen type I and III. Arterial spectra were markedly different between the thoracic and carotid specimens. There was also a significant elevation (pcarotid specimens. Conclusion: Fluorescence spectroscopy is an effective method for evaluating ECM (collagen and elastin) associated
Numerical observer for atherosclerotic plaque classification in spectral computed tomography.
Lorsakul, Auranuch; Fakhri, Georges El; Worstell, William; Ouyang, Jinsong; Rakvongthai, Yothin; Laine, Andrew F; Li, Quanzheng
Spectral computed tomography (SCT) generates better image quality than conventional computed tomography (CT). It has overcome several limitations for imaging atherosclerotic plaque. However, the literature evaluating the performance of SCT based on objective image assessment is very limited for the task of discriminating plaques. We developed a numerical-observer method and used it to assess performance on discrimination vulnerable-plaque features and compared the performance among multienergy CT (MECT), dual-energy CT (DECT), and conventional CT methods. Our numerical observer was designed to incorporate all spectral information and comprised two-processing stages. First, each energy-window domain was preprocessed by a set of localized channelized Hotelling observers (CHO). In this step, the spectral image in each energy bin was decorrelated using localized prewhitening and matched filtering with a set of Laguerre-Gaussian channel functions. Second, the series of the intermediate scores computed from all the CHOs were integrated by a Hotelling observer with an additional prewhitening and matched filter. The overall signal-to-noise ratio (SNR) and the area under the receiver operating characteristic curve (AUC) were obtained, yielding an overall discrimination performance metric. The performance of our new observer was evaluated for the particular binary classification task of differentiating between alternative plaque characterizations in carotid arteries. A clinically realistic model of signal variability was also included in our simulation of the discrimination tasks. The inclusion of signal variation is a key to applying the proposed observer method to spectral CT data. Hence, the task-based approaches based on the signal-known-exactly/background-known-exactly (SKE/BKE) framework and the clinical-relevant signal-known-statistically/background-known-exactly (SKS/BKE) framework were applied for analytical computation of figures of merit (FOM). Simulated data of a
Serial changes of coronary atherosclerotic plaque: Assessment with 64-slice multi-detector computed tomography
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Kim, Eun Young; Kang, Doo Kyoung; Sun, Joo Sung; Choi, So Yeon [Ajou University School of Medicine, Suwon (Korea, Republic of)
Evaluate the progression of coronary atherosclerotic plaque during follow-up, and its association with cardiovascular risk factors. Fifty-six atherosclerotic patients with plaque were enrolled in this retrospective study. Patient's plaque was detected on repeat 64-slice multidetector CT scans with a mean interval of 25 ± 10 months changes in calcified and non-calcified plaque volumes and cardiovascular risk factors were assessed over time. Absolute and relative changes in plaque volume were compared, and the association between rapid progression and cardiovascular risk factors was determined. Diameter of the stenosis, length, calcified and non-calcified lesion plaque volumes increased significantly on follow-up CT. Absolute and relative annual changes in plaque volumes were significantly greater in non-calcified plaque (median, 22.7 mm{sup 3}, 90.4%) than in calcified plaque (median, 0.7 mm{sup 3}, 0%). Obesity, smoking, hypertension, hypercholesterolemia, and low high-density lipoprotein were significant predictors of progression of non-calcified plaque. Progression of calcified plaque was not associated with any cardiovascular risk factors. Coronary plaque volume increased significantly on follow-up CT. The rate of progression is related to non-calcified plaque than to calcified plaque. Cardiovascular risk factors are independently associated with the rapid progression of non-calcified plaque volume, but not associated with the progression of calcified plaque.
Serial changes of coronary atherosclerotic plaque: Assessment with 64-slice multi-detector computed tomography
International Nuclear Information System (INIS)
Evaluate the progression of coronary atherosclerotic plaque during follow-up, and its association with cardiovascular risk factors. Fifty-six atherosclerotic patients with plaque were enrolled in this retrospective study. Patient's plaque was detected on repeat 64-slice multidetector CT scans with a mean interval of 25 ± 10 months changes in calcified and non-calcified plaque volumes and cardiovascular risk factors were assessed over time. Absolute and relative changes in plaque volume were compared, and the association between rapid progression and cardiovascular risk factors was determined. Diameter of the stenosis, length, calcified and non-calcified lesion plaque volumes increased significantly on follow-up CT. Absolute and relative annual changes in plaque volumes were significantly greater in non-calcified plaque (median, 22.7 mm3, 90.4%) than in calcified plaque (median, 0.7 mm3, 0%). Obesity, smoking, hypertension, hypercholesterolemia, and low high-density lipoprotein were significant predictors of progression of non-calcified plaque. Progression of calcified plaque was not associated with any cardiovascular risk factors. Coronary plaque volume increased significantly on follow-up CT. The rate of progression is related to non-calcified plaque than to calcified plaque. Cardiovascular risk factors are independently associated with the rapid progression of non-calcified plaque volume, but not associated with the progression of calcified plaque.
Resolution of apoptosis in atherosclerotic plaque by dietary modification and statin therapy
Hartung, D; Sarai, M; Petrov, A.; Kolodgie, F; Narula, N.; Verjans, J.; Virmani, R; Reutelingsperger, C; Hofstra, L; Narula, J
Although apoptosis within atherosclerotic plaques is associated with plaque vulnerability and rupture, the role of inhibition of the apoptotic process is not clear. We evaluated the impact of dietary modification and statin therapy (measures known to favorably influence outcomes in coronary disease) on the incidence of apoptosis in experimental atherosclerotic lesions. Methods: A total of 30 animals were studied; 1 group of 6 animals served as the controls (group 1), and the remaining 24 anim...
Plaque Rupture and Thrombosis: the Value of the Atherosclerotic Rabbit Model in Defining the Mechanism.
Abela, Oliver G; Ahsan, Chowdhury H; Alreefi, Fadi; Salehi, Negar; Baig, Imran; Janoudi, Abed; Abela, George S
Persistent inflammation and mechanical injury associated with cholesterol crystal accretion within atherosclerotic plaques typically precedes plaque disruption (rupture and/or erosion) and thrombosis-often the terminal events of atherosclerotic cardiovascular disease. To elucidate the mechanisms of these events, the atherosclerotic rabbit model provides a unique and powerful tool that facilitates studies of atherogenesis starting with plaque buildup to eventual disruption. Examination of human coronary arteries obtained from patients who died with myocardial infarction demonstrates evidence of cholesterol crystals perforating the plaque cap and intimal surface of the arterial wall that can lead to rupture. These observations were made possible by omitting ethanol, an avid lipid solvent, from the tissue processing steps. Importantly, the atherosclerotic rabbit model exhibits a similar pathology of cholesterol crystals perforating the intimal surface as seen in ruptured human plaques. Local and systemic inflammatory responses in the model are also similar to those observed in humans. The strong parallel between the rabbit and human pathology validates the atherosclerotic rabbit model as a predictor of human pathophysiology of atherosclerosis. Thus, the atherosclerotic rabbit model can be used with confidence to evaluate diagnostic imaging and efficacy of novel anti-atherosclerotic therapy. PMID:27091328
Identification of atherosclerotic plaque components with intravascular ultrasound elastography in vivo: a Yucatan pig study.
Korte, C.L. de; Sierevogel, M.J.; Mastik, F.; Strijder, C.; Schaar, J.A.; Velema, E.; Pasterkamp, G.; Serruys, P.W.; Steen, A.F.W. van der
BACKGROUND: Intravascular ultrasound elastography assesses the local strain of the atherosclerotic vessel wall. In the present study, the potential to identify different plaque components in vivo was investigated. METHODS AND RESULTS: Atherosclerotic external iliac and femoral arteries (n=24) of 6 Y
Characterization of HSP27 phosphorylation sites in human atherosclerotic plaque secretome
DEFF Research Database (Denmark)
Durán, Mari-Carmen; Boeri-Erba, Elisabetta; Mohammed, Shabaz;
-lymphocytes). These interactions can be mediated by proteins secreted from these cells, which therefore exert an important role in the atherosclerotic process. We recently described a novel strategy for the characterization of the human atherosclerotic plaque secretome, combining two-dimensional gel electrophoresis...... are unknown. Thus, the role that phosphorylated HSP27 could play in the atherosclerotic process is actually under study. The present work shows the strategies employed to characterize the phosphorylation in the HSP27 secreted by atheroma plaque samples. The application of liquid chromatography tandem...
Inhibiting extracellular matrix metalloproteinase inducer maybe beneficial for diminishing the atherosclerotic plaque instability
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Xie S
Full Text Available Atherosclerotic plaque rupture and local thrombosis activation in the artery cause acute serious incidents such as acute coronary syndrome and stroke. The exact mechanism of plaque rupture remains unclear but excessive degradation of the extracellular matrix scaffold by matrix-degrading metalloproteinases (MMPs has been implicated as one of the major molecular mechanisms in this process. Convincing evidence is available to prove that extracellular matrix metalloproteinase inducer (EMMPRIN induces MMP expression and is involved in the inflammatory responses in the artery wall. The inflammation and MMPs have been shown to play a critical role for atherosclerotic lesion development and progression. More recent data showed that increased EMMPRIN expression was associated with vulnerable atherosclerotic lesions. Therefore, we speculate that EMMPRIN may be pivotal for atherosclerotic plaque instability, and hence inhibition of EMMPRIN expression could be a promising approach for the prevention or treatment of atheroma instability.
Development of a near infrared fluorescence catheter: operating characteristics and feasibility for atherosclerotic plaque detection
International Nuclear Information System (INIS)
We present a one-dimensional optical fibre-based imaging catheter specifically developed for the atherosclerotic plaque detection of emerging novel near infrared fluorescence imaging agents. We show that femtomole amounts of fluorochromes can be detected, especially in the presence of a blood-free medium. We further studied the catheter responses for a wide range of laser powers and biologically relevant concentrations of fluorochrome. In vitro tissue-like phantoms and human carotid plaque specimen measurements further demonstrate the feasibility of atherosclerotic plaque detection
Uptake of 68gallium in atherosclerotic plaques in LDLR-/-ApoB100/100 mice
Silvola, Johanna MU; Laitinen, Iina; Sipilä, Henri J; Laine, V Jukka O; Leppänen, Pia; Ylä-Herttuala, Seppo; Knuuti, Juhani; Roivainen, Anne
Background Atherosclerosis is a chronic inflammatory disease of artery wall characterized by infiltration of monocytes into subendothelial space and their differentiation into macrophages. Since rupture-prone plaques commonly contain high amounts of activated macrophages, imaging of the macrophage content may provide a useful tool for the evaluation of plaque vulnerability. The purpose of this study was to explore the uptake of 68gallium (68Ga) in atherosclerotic plaques in mice. Methods Upta...
Direct association between diet and the stability of human atherosclerotic plaque
Isabel Gonçalves; Elisavet Andersson Georgiadou; Sören Mattsson; Göran Skog; Luís Pedro; José Fernandes e Fernandes; Nuno Dias; Gunnar Engström; Jan Nilsson; Kristina Stenström
Mediterranean diet has been suggested to explain why coronary heart disease mortality is lower in southern than northern Europe. Dietary habits can be revealed by isotope ratio mass spectrometry (IRMS) measurement of carbon (δ(13)C) and nitrogen (δ(15)N) in biological tissues. To study if diet is associated with human plaque stability, atherosclerotic plaques from carotid endarterectomy on 56 patients (21 Portuguese and 35 Swedish) were analysed by IRMS and histology. Plaque components affect...
Evaluation of the early enhancement of coronary atherosclerotic plaque by contrast-enhanced MR angiography
International Nuclear Information System (INIS)
Purpose: To evaluate the early enhancement of coronary atherosclerotic plaque using contrast-enhanced MR angiography (CE-MRA) and investigate the association between unstable angina pectoris (UAP) and early enhancement of the plaque. Methods: Forty-one patients presenting with angina pectoris and demonstrating single-vessel disease with non-calcified plaque and significant coronary stenosis (≥50%) on CTA were consecutively recruited for coronary CE-MRA. Contrast-to-noise ratio of the culprit plaque guided by CTA was measured on a cross-sectional multi-planar reconstruction image of the plaque on both pre- and post-CE-MRA. A 50% increasing of CNR was defined as plaque enhancement. The association between early enhancement of the plaques and UAP was analyzed. Results: Thirty-seven non-calcified plaques with significant coronary stenosis were detected in the 37 patients on MRA. 4 subjects were excluded because coronary atherosclerotic plaques were inadequate for identification on MRA. Of the 37 patients, 18 patients had UAP and other 19 patients presented stable angina pectoris (SAP). Of the 37 plaques on CE-MRA, 13 and 24 plaques presented early enhancement and no enhancement, respectively. Of the 13 early-enhanced plaques, 11 (85%) and 2 (15%) were found in the patients with UAP and SAP, respectively (p < 0.01). Of the 37 patients, 11 (61%) with UAP and 2 (11%) with SAP had early-enhanced plaques, respectively (p < 0.01). Conclusion: CE-MRA allows detection of early enhancement of coronary atherosclerotic plaque. The early enhancement is common in unstable angina and could be a sign of vulnerability.
A framework for the co-registration of hemodynamic forces and atherosclerotic plaque components
International Nuclear Information System (INIS)
Local hemodynamic forces, such as wall shear stress (WSS), are thought to trigger cellular and molecular mechanisms that determine atherosclerotic plaque vulnerability to rupture. Magnetic resonance imaging has emerged as a powerful tool to characterize human carotid atherosclerotic plaque composition and morphology, and to identify plaque features shown to be key determinants of plaque vulnerability. Image-based computational fluid dynamics has allowed researchers to obtain time-resolved WSS information of atherosclerotic carotid arteries. A deeper understanding of the mechanisms of initiation and progression of atherosclerosis can be obtained through the comparison of WSS and plaque composition and morphology. To date, however, advance in knowledge has been limited greatly due to the lack of a reliable infrastructure to perform such analysis. The aim of this study is to establish a framework that will allow for the co-registration and analysis of the three-dimensional distribution of WSS and plaque components and morphology. The use of this framework will lead to future studies targeted to determining the role of WSS in atherosclerotic plaque progression and vulnerability. (paper)
Significance of ultrasound evaluation of carotid atherosclerotic plaque for diagnosing ischemic cerebrovascular disease
Institute of Scientific and Technical Information of China (English)
BACKGROUND: Carotid artery is the main source for craniocerebral blood supply. Its intimal plaque formation and arterial stenosis degree both are the risk factors for ischemic cerebrovascular disease.Therefore, the close relationship of carotid atherosclerotic plaque and ischemic cerebrovascular disease, and ultrasound evaluation of carotid atherosclerotic plaque have become the hot spot in studying ischemic cerebrovascular disease.OBJECTIVE: This study was to detect the degree of carotid atherosclerosis of ischemic cerebrovascular disease patients by ultrasonography, and to analyze the situation of carotid atherosclerosis and its relationship with clinic.DESIGN: Clinical randomized concurrent control experiment.SETTING: Lintong Convalescent Hospital of Lanzhou Military Area Command of Chinese PLA.PARTICIPANTS: Totally 60 outpatients and inpatients with ischemic cerebrovascular disease, 42 males and 18 females, admitted to Lintong Convalescent Hospital of Lanzhou Military Area Command of Chinese PLA between January 2006 and December 2006 were involved in the patient group. They met the diagnosis criteria of ischemic cerebrovascular disease constituted by the 4th Cerebrovascular Disease Conference in 1996, and were confirmed to suffer from ischemic cerebrovascular disease by skull CT and MRI. Another 20 subjects who received healthy examination concurrently in the same hospital, 12 males and 8 females, were involved in the control group. Informed consents of detected items were obtained from involved subjects.METHODS: The plaque thickness of mid portion, distal end and crotch of common carotid artery (CCA),internal carotid artery (ICA), external carotid artery (ECA) and vertebral artery (VA) of involved subjects,who received health examination was separately detected with color Doppler ultrasonograph (HDI-5000).Then, total integral of plaque was calculated. The intima-media thickness (IMT) was measured with two-dimensional ultrasonography. The inner diameter
Support vector machine based classification and mapping of atherosclerotic plaques using fluorescence lifetime imaging (Conference Presentation)
Fatakdawala, Hussain; Gorpas, Dimitris S.; Bec, Julien; Ma, Dinglong M.; Yankelevich, Diego R.; Bishop, John W.; Marcu, Laura
The progression of atherosclerosis in coronary vessels involves distinct pathological changes in the vessel wall. These changes manifest in the formation of a variety of plaque sub-types. The ability to detect and distinguish these plaques, especially thin-cap fibroatheromas (TCFA) may be relevant for guiding percutaneous coronary intervention as well as investigating new therapeutics. In this work we demonstrate the ability of fluorescence lifetime imaging (FLIm) derived parameters (lifetime values from sub-bands 390/40 nm, 452/45 nm and 542/50 nm respectively) for generating classification maps for identifying eight different atherosclerotic plaque sub-types in ex vivo human coronary vessels. The classification was performed using a support vector machine based classifier that was built from data gathered from sixteen coronary vessels in a previous study. This classifier was validated in the current study using an independent set of FLIm data acquired from four additional coronary vessels with a new rotational FLIm system. Classification maps were compared to co-registered histological data. Results show that the classification maps allow identification of the eight different plaque sub-types despite the fact that new data was gathered with a different FLIm system. Regions with diffuse intimal thickening (n=10), fibrotic tissue (n=2) and thick-cap fibroatheroma (n=1) were correctly identified on the classification map. The ability to identify different plaque types using FLIm data alone may serve as a powerful clinical and research tool for studying atherosclerosis in animal models as well as in humans.
16S rRNA-based detection of oral pathogens in coronary atherosclerotic plaque
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Mahendra Jaideep
Full Text Available Background: Atherosclerosis develops as a response of the vessel wall to injury. Chronic bacterial infections have been associated with an increased risk for atherosclerosis and coronary artery disease. The ability of oral pathogens to colonize in coronary atheromatous plaque is well known. Aim: The aim of this study was to detect the presence of Treponema denticola, Porphyromonas gingivalis and Campylobacter rectus in the subgingival and atherosclerotic plaques of patients with coronary artery disease. Materials and Methods: Fifty-one patients in the age group of 40-80 years with coronary artery disease were selected for the study. DNA was extracted from the plaque samples. The specific primers for T. denticola, C. rectus and P. gingivalis were used to amplify a part of the 16S rRNA gene by polymerase chain reaction. Statistical Analysis Used: Chi-square analysis, correlation coefficient and prevalence percentage of the microorganisms were carried out for the analysis. Results: Of the 51 patients, T. denticola, C. rectus and P. gingivalis were detected in 49.01%, 21.51% and 45.10% of the atherosclerotic plaque samples. Conclusions: Our study revealed the presence of bacterial DNA of the oral pathogenic microorganisms in coronary atherosclerotic plaques. The presence of the bacterial DNA in the coronary atherosclerotic plaques in significant proportion may suggest the possible relationship between periodontal bacterial infection and genesis of coronary atherosclerosis.
Cross-Polarization Optical Coherence Tomography in Evaluation of Atherosclerotic Plaque Structure
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Gubarkova Е.V.
Full Text Available The cross-polarization optical coherence tomography (CP OCT technique allows for tissue structure imaging by registration of backscattered radiation in initial and orthogonal polarizations and further comparison of the obtained images. Spatial structure of collagen fibers gives rise not only to backscattering of probing radiation, but also to evolution of its polarization state during propagation through the tissue (depolarization. Collagen fibers of the fibrous cap play a key role in determining the stability of atherosclerotic plaques. Inflammation observed in atherosclerosis is the principal mechanism of collagen fibers disorganization, therefore, the assessment of the depolarizing properties of the fibrous cap can characterize an atherosclerotic plaque as being "vulnerable" to rupture. The aim of the study was to evaluate CP OCT efficiency to determine the condition of collagen fibers of an atherosclerotic plaque fibrous cap, which characterize its "vulnerability". Materials and Methods. 54 post mortem samples of intact human aorta and aorta with atherosclerotic plaques at different stages were studied. The study involved 150 CP OCT-images in which the value of OCT signal in orthogonal polarization was used to evaluate the ratio of organized and disorganized by inflammation collagen fibers within the fibrous cap. For histological imaging comparison we used hematoxylin-eosine and picrosirius red staining with evaluation in polarized light. Numerical analysis of CP OCT-images was used as a complementary tool for visual assessment. Results. We showed CP OCT to have significant advantages over the traditional OCT in the assessment of atherosclerotic plaque. In orthogonal CP OCT-image one can differentiate the main structural components of a plaque: a fibrous cap and a lipid core. The thickness of the fibrous cap in the orthogonal polarization image correlates with the thickness of the fibrous cap measured from histological preparations
Study of 99mTc-Ap4A in detection of experimental atherosclerotic plaques
International Nuclear Information System (INIS)
, blood samples, atherosclerotic plaques and normal aortic walls were removed. Lesions to blood (target/blood, T/B), lesions to normal (target/non-target, T/NT) ratios were calculated. 74 MBq 99mTc-Ap4A was injected into marginal ear veins of 5 atherosclerotic and 5 normal NZW rabbits. Simultaneously in vivo gamma camera images were recorded for more than 4 hours. In another group, 30 minutes after 99mTc-Ap4A administrated, the animals were sacrificed and their aortas were removed. The aortas were placed on the face of gamma camera (3 mm diameter pin-hole collimater) and image acquisition was performed. Results: The radiochemistry purity of 99mTc-Ap4A was 85% to 91%. Biodistribution study revealed 99mTc-Ap4A cleared from blood rapidly. 30 minutes after 99mTc-Ap4A administrated, T/B ratio was 3.17±1.27, T/NT ratio was 5.23±1.87. On the radioautograms shadows of atherosclerotic plaques were clearly visible. The aortas with atherosclerotic plaques also can be seen on ex vivo images. Atherosclerotic abdominal aortas and lesions were clearly visible on in vivo images 15 minutes to 3 hours after 99mTc-Ap4A administrated. Conclusion: 99mTc-labeled Ap4A has potential for rapid noninvasive detection of plaque formation. The results were similar to the report of Elmaleh. As an atherosclerotic imaging agent 99mTc-Ap4A got better images than we previously reported radioiodine labeled SP-4
Effects of Mechanical Properties and Atherosclerotic Artery Size on Biomechanical Plaque Disruption - Mouse versus Human
Riou, Laurent M.; Broisat, Alexis; Ghezzi, Catherine; Finet, Gérard; Rioufol, Gilles; Gharib, Ahmed M.; Pettigrew, Roderic I.; Ohayon, Jacques
Mouse models of atherosclerosis are extensively being used to study the mechanisms of atherosclerotic plaque development and the results are frequently extrapolated to humans. However, major differences have been described between murine and human atherosclerotic lesions and the determination of similarities and differences between these species has been largely addressed recently. This study takes over and extends previous studies performed by our group and related to the biomechanical chara...
Ex vivo coronary atherosclerotic plaque characterization with multi-detector-row CT
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Multi-detector-row CT angiography (CTA) is a new technology that allows for non-invasive investigation of coronary atherosclerosis in patients. The relation between the morphology of atherosclerotic plaques assessed by CTA and histopathology is unknown. We investigated 11 human cadaver heart specimens. A mixture of methylcellulose and CT contrast media was injected into the coronary arteries to achieve in-vivo-like contrast enhancement within the coronary artery lumen. The morphologic pattern of atherosclerotic lesions found on CTA images and the tissue attenuation of non-calcified plaques were determined. After CTA imaging, atherosclerotic lesions in the coronary arteries were macroscopically identified and characterized histopathologically according to American Heart Association criteria. A total of 50 and 40 lesions were found macroscopically and by CTA, respectively. Thirty-three lesions could have been compared directly. The sensitivity of CTA compared with macroscopic detection of atheromas, fibroatheromas, fibrocalcified, and calcified lesions was 73, 70, 86, and 100%, respectively. The mean CT attenuation of predominantly lipid-rich and fibrous-rich plaques was significantly different (47±9 and 104±28 HU, respectively; p<0.01). Atherosclerotic coronary plaques detected by CTA may represent different stages of coronary atherosclerosis. The tissue attenuation of non-calcified plaques may allow for assessment of their predominant component. (orig.)
Human macrophage foam cells degrade atherosclerotic plaques through cathepsin K mediated processes
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Barascuk, Natasha; Skjøt-Arkil, Helene; Register, Thomas C; Larsen, Lise; Byrjalsen, Inger; Christiansen, Claus; Karsdal, Morten A
BACKGROUND: Proteolytic degradation of Type I Collagen by proteases may play an important role in remodeling of atherosclerotic plaques, contributing to increased risk of plaque rupture.The aim of the current study was to investigate whether human macrophage foam cells degrade the extracellular...... matrix (ECM) of atherosclerotic plaques by cathepsin K mediated processes. METHODS: We 1) cultured human macrophages on ECM and measured cathepsin K generated fragments of type I collagen (C-terminal fragments of Type I collagen (CTX-I) 2) investigated the presence of CTX-I in human coronary arteries and......-I in areas of intimal hyperplasia and in shoulder regions of advanced plaques. Treatment of human monocytes with M-CSF or M-CSF+LDL generated macrophages and foam cells producing CTX-I when cultured on type I collagen enriched matrix. Circulating levels of CTX-I were not significantly different in...
The content of copper and zinc in human ulcered atherosclerotic plaque
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Radak Đorđe
Full Text Available INTRODUCTION Copper and zinc have significant antiatherogenic effect influencing activity of antioxidant enzyms (giutathion-peroxidase i superoxid-dismutase, mechanism of apoptosis and other mechanisms. Few studies showed increased copper and zinc concentration in atherosclerotic plaque in comparison to normal vascular tissue. AIM The aim of the study was to compare copper and zinc concentrations in carotid artery tissue without significant atherosclerotic changes and human ulcered atherosclerotic plaque. MATERIAL AND METHODS Study was conducted on 66 patients. Carotid endarterectomy due to the significant carotid atherosclerotic changes with cerebrovascular disorders was performed in 54 patients (81.8%. Control group consisted of 12 patients (18.2% without carotid atherosclerotic changes operated due to the symptomatic kinking and coiling of carotid artery. Operated group consisted of 38 man (62.96% and 16 woman (37.04%. Control group had the same number of patients: six men (50% and six women (50%. Preoperatively, all patients were examined by vascular surgeon, neurologist and cardiologist. Duplex sonografy of carotid and vertebral arteries was performed by Aloca DSD 630 ultrasound with mechanical and linear transducer 7.7 MHz. Indication for surgical treatment was obtained according to non-invasive diagnostic protocol and neurological symptoms. Copper and zinc concentration in human ulcered atherosclerotic plaque and carotid artery segment were estimated by spectophotometry (Varian AA-5. RESULTS Average age of our patients was 59.8±8.1 years. For males average age was 76.1 ±9.8 years. And for females 42.4±5.8 years. In group with carotid endarterectomy female patients were significantly younger than male patients (p<0.01. In group with carotid endarterectomy clinically determined neurological disorders were found in 47 patients (87.03%-35 male (74.47% and 12 female patients (25.53%. Regarding risk factors for cardiovascular diseases, no
68Ga-DOTA-RGD peptide: biodistribution and binding into atherosclerotic plaques in mice
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Increased expression of αvβ3/αvβ5 integrin is involved in angiogenesis and the inflammatory process in atherosclerotic plaques. The novel 68Ga-DOTA-RGD peptide binds with high affinity to αvβ3/αvβ5 integrin. The aim of this study was to investigate the uptake of the 68Ga-DOTA-RGD peptide in atherosclerotic plaques. Uptake of intravenously administered 68Ga-DOTA-RGD peptide was studied ex vivo in excised tissue samples and aortic sections of LDLR-/-ApoB100/100 atherosclerotic mice. The uptake of the tracer in aortic cryosections was examined by using digital autoradiography. Subsequently, the autoradiographs were combined with histological and immunohistological analysis of the sections. DOTA-RGD peptide was successfully labelled with the generator-produced 68Ga. The tracer had reasonably good specific radioactivity (8.7 ± 1.1 GBq/μmol) and was quite stable in vivo. According to ex vivo biodistribution results, 68Ga-DOTA-RGD was cleared rapidly from the blood circulation and excreted through the kidneys to the urine with high radioactivity in the intestine, lungs, spleen and liver. Autoradiography results showed significantly higher uptake of 68Ga-DOTA-RGD peptide in the atherosclerotic plaques compared to healthy vessel wall (mean ratio ± SD 1.4 ± 0.1, p = 0.0004). We observed that 68Ga-DOTA-RGD is accumulated into the plaques of atherosclerotic mice. However, this data only shows the feasibility of the approach, while the clinical significance still remains to be proven. Further studies are warranted to assess the uptake of this tracer into human atherosclerotic plaques. (orig.)
Assessment of 320-slice computed tomography angiography in distinguishing hemorrhage in carotid atherosclerotic plaques
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Xiao-jie ZHANG
Full Text Available Objective To assess the value of 320⁃slice computed tomography angiography (CTA in distinguishing hemorrhage/thrombus from lipid-rich necrotic core (LRNC in atherosclerotic plaques of carotid artery. Methods Thirty-seven subjects who prepared to perform carotid endarterectomy (CEA, with stenosis rate about 50%-99% in at least unilateral carotid artery detected by ultrasound, were enrolled in this study. Both 320-slice CTA and 3.0T high-resolution MRI were conducted within one week before operation. CTA, MRI and pathological sections were matched with the carotid bifurcation and calcification features as the mark. According to American Heart Association (AHA modified classification, CT slices were selected and divided into 2 groups: Type Ⅳ -Ⅴ (lipid plaques and Type Ⅵ (hemorrhage plaques, and the density difference between lipid plaques and hemorrhage/thrombus plaques was analyzed. Results A total of 217 slices were included in final analysis, including 88 slices of Type Ⅳ -Ⅴ (lipid plaques and 129 slices of Type Ⅵ (hemorrhage plaques. There was statistically significant difference in CT value between 2 groups. The mean CT value of lipid necrosis core in Type Ⅳ -Ⅴ and hemorrhage/thrombus in Type Ⅵ was (28.07 ± 26.84 and (97.17 ± 35.82 HU respectively, and the former was significantly lower than the latter (t = 16.141, P = 0.000. Conclusions CTA can distinguish hemorrhage/thrombus from lipid-rich necrotic core in carotid atherosclerotic plaques.
Thiocyanate supplementation decreases atherosclerotic plaque in mice expressing human myeloperoxidase
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Morgan, P E; Laura, R P; Maki, R A;
appreciably altered. Serum MPO levels steadily increased in mice on the high-fat diet, however, comparison of SCN(-)-supplemented versus control mice showed no significant changes in MPO protein, cholesterol, or triglyceride levels; thiol levels were decreased in supplemented mice at one time-point. Plaque...... curve (AUC). Mean serum SCN(-) concentrations were elevated in the supplemented mice (200-320 μM) relative to controls (< 120 μM). Normalized aortic root plaque areas at sacrifice were 26% lower in the SCN(-)-supplemented mice compared with controls (P = 0.0417), but plaque morphology was not...
Dichotomy in Hedgehog Signaling between Human Healthy Vessel and Atherosclerotic Plaques
Queiroz, Karla C. S.; Bijlsma, Maarten F.; Tio, Rene A.; Zeebregts, Clark J.; Dunaeva, Marina; Ferreira, Carmen V.; Fuhler, Gwenny M.; Kuipers, Ernst J.; Alves, Maria M.; Rezaee, Farhad; Spek, C. Arnold; Peppelenbosch, Maikel P.
The major cause for plaque instability in atherosclerotic disease is neoangiogenic revascularization, but the factors controlling this process remain only partly understood. Hedgehog (HH) is a morphogen with important functions in revascularization, but its function in human healthy vessel biology a
Detection of Fungal Elements in Atherosclerotic Plaques Using Mycological, Pathological and Molecular Methods
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Omid MASOUMI
Full Text Available Background: The aim of this study was to detect fungi in atherosclerotic plaques and investigate their possible role in atherosclerosis.Methods: Coronary atherosclerotic plaques specimen were obtained from patients with atherosclerosis. Direct exami-nation, culture, histopathology study, PCR and sequencing were performed to detect/identify the mycotic elements in the plaques. Age, sex, smoking, obesity, hypertension, hyperlipidemia, family history of heart diseases and diabetes were considered and data were analyzed using Chi Square test by SPSS version 15.Results: A total of 41 specimens were analyzed. Direct examination for fungal elements was negative in all cases but in culture only one specimen grew as a mold colony. The presence of fungal elements were confirmed in 6 and 2 tissue sections stained by Gomori methenamine silver and Hematoxylin and Eosin methods, respectively. Using PCR, 11 cases were positive for fungi. The DNA sequence analysis of six positive specimens which were randomly selected revealed fungi as Candida albicans (n=3, Candida guilliermondii (n=2 and Monilia sp. (n=1.Conclusion: A significant association between the presence of fungi in atherosclerotic plaques and severity of athero-genesis and atherosclerotic disease was not found. This could be due to limited numbers of patients included in our study. However, the presence of fungal elements in 26.8% of our specimens is considerable and the results does not exclude the correlation between the presence of fungi with atherosclerosis and coronary artery disease.
Peptidoglycan in atherosclerotic plaque formation and vulnerability
Oude Nijhuis, M.M.
The studies described in this thesis suggest that peptidoglycan (PG) is involved in initiation and progression of atherosclerosis. PG is an antigen that can be found in large amounts in the Gram-positive bacterial wall and only in small amounts in the Gram-negative bacterial wall. PG is able to stimulate the Toll-like receptor 2 (TLR2), a receptor that plays an important role in the innate immune system. In the normal situation PG is present in the intestinal mucosal flora, but under certain ...
Visfatin Destabilizes Atherosclerotic Plaques in Apolipoprotein E-Deficient Mice.
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Bo Li
Full Text Available Although there is evidence that visfatin is associated with atherogenesis, the effect of visfatin on plaque stability has not yet been explored.In vivo, vulnerable plaques were established by carotid collar placement in apolipoprotein E-deficient (ApoE-/- mice, and lentivirus expressing visfatin (lenti-visfatin was locally infused in the carotid artery. The lipid, macrophage, smooth muscle cell (SMC and collagen levels were evaluated, and the vulnerability index was calculated. In vitro, RAW264.7 cells were stimulated with visfatin, and the MMPs expressions were assessed by western blot and immunofluorescence. And the mechanism that involved in visfatin-induced MMP-8 production was investigated.Transfection with lenti-visfatin significantly promoted the expression of visfatin which mainly expressed in macrophages in the plaque. Lenti-visfatin transfection significantly promoted the accumulation of lipids and macrophages, modulated the phenotypes of smooth muscle cells and decreased the collagen levels in the plaques, which significantly decreased the plaque stability. Simultaneously, transfection with lenti-visfatin significantly up-regulated the expression of MMP-8 in vivo, as well as MMP-1, MMP-2 and MMP-9. Recombinant visfatin dose- and time-dependently up-regulated the in vitro expression of MMP-8 in macrophages. Visfatin promoted the translocation of NF-κB, and inhibition of NF-κB significantly reduced visfatin-induced MMP-8 production.Visfatin increased MMP-8 expression, promoted collagen degradation and increased the plaques vulnerability index.
A statin-loaded reconstituted high-density lipoprotein nanoparticle inhibits atherosclerotic plaque inflammation
Duivenvoorden, Raphaël; Tang, Jun; Cormode, David P.; Mieszawska, Aneta J.; Izquierdo-Garcia, David; Ozcan, Canturk; Otten, Maarten J.; Zaidi, Neeha; Lobatto, Mark E.; van Rijs, Sarian M.; Priem, Bram; Kuan, Emma L.; Martel, Catherine; Hewing, Bernd; Sager, Hendrik; Nahrendorf, Matthias; Randolph, Gwendalyn J.; Stroes, Erik S. G.; Fuster, Valentin; Fisher, Edward A.; Fayad, Zahi A.; Mulder, Willem J. M.
Inflammation is a key feature of atherosclerosis and a target for therapy. Statins have potent anti-inflammatory properties but these cannot be fully exploited with oral statin therapy due to low systemic bioavailability. Here we present an injectable reconstituted high-density lipoprotein (rHDL) nanoparticle carrier vehicle that delivers statins to atherosclerotic plaques. We demonstrate the anti-inflammatory effect of statin-rHDL in vitro and show that this effect is mediated through the inhibition of the mevalonate pathway. We also apply statin-rHDL nanoparticles in vivo in an apolipoprotein E-knockout mouse model of atherosclerosis and show that they accumulate in atherosclerotic lesions in which they directly affect plaque macrophages. Finally, we demonstrate that a 3-month low-dose statin-rHDL treatment regimen inhibits plaque inflammation progression, while a 1-week high-dose regimen markedly decreases inflammation in advanced atherosclerotic plaques. Statin-rHDL represents a novel potent atherosclerosis nanotherapy that directly affects plaque inflammation.
Modeling of Mechanical Stress Exerted by Cholesterol Crystallization on Atherosclerotic Plaques
Cui, Dongyao; Yu, Xiaojun; Chen, Si; Liu, Xinyu; Tang, Hongying; Wang, Xianghong; Liu, Linbo
Plaque rupture is the critical cause of cardiovascular thrombosis, but the detailed mechanisms are not fully understood. Recent studies have found abundant cholesterol crystals in ruptured plaques, and it has been proposed that the rapid expansion of cholesterol crystals in a limited space during crystallization may contribute to plaque rupture. To evaluate the effect of cholesterol crystal growth on atherosclerotic plaques, we modeled the expansion of cholesterol crystals during the crystallization process in the necrotic core and estimated the stress on the thin cap with different arrangements of cholesterol crystals. We developed a two-dimensional finite element method model of atherosclerotic plaques containing expanding cholesterol crystals and investigated the effect of the magnitude and distribution of crystallization on the peak circumferential stress born by the cap. Using micro-optical coherence tomography (μOCT), we extracted the cross-sectional geometric information of cholesterol crystals in human atherosclerotic aorta tissue ex vivo and applied the information to the model. The results demonstrate that (1) the peak circumference stress is proportionally dependent on the cholesterol crystal growth; (2) cholesterol crystals at the cap shoulder impose the highest peak circumference stress; and (3) spatial distributions of cholesterol crystals have a significant impact on the peak circumference stress: evenly distributed cholesterol crystals exert less peak circumferential stress on the cap than concentrated crystals. PMID:27149381
A Statin-Loaded Reconstituted High-Density Lipoprotein Nanoparticle Inhibits Atherosclerotic Plaque Inflammation
Duivenvoorden, Raphaël; Tang, Jun; Cormode, David P.; Mieszawska, Aneta J.; Izquierdo-Garcia, David; Ozcan, Canturk; Otten, Maarten J.; Zaidi, Neeha; Lobatto, Mark E.; van Rijs, Sarian M.; Priem, Bram; Kuan, Emma L.; Martel, Catherine; Hewing, Bernd; Sager, Hendrik; Nahrendorf, Matthias; Randolph, Gwendalyn J.; Stroes, Erik S.G.; Fuster, Valentin; Fisher, Edward A.; Fayad, Zahi A.; Mulder, Willem J.M.
Inflammation is a key feature of atherosclerosis and a target for therapy. Statins have potent anti-inflammatory properties but these cannot be fully exploited with oral statin therapy due to low systemic bioavailability. Here we present an injectable reconstituted high-density lipoprotein (rHDL) nanoparticle carrier vehicle that delivers statins to atherosclerotic plaques. We demonstrate the anti-inflammatory effect of statin-rHDL in vitro and show this effect is mediated through inhibition of the mevalonate pathway. We also apply statin-rHDL nanoparticles in vivo in an apolipoprotein E-knockout mouse model of atherosclerosis and show they accumulate in atherosclerotic lesions where they directly affect plaque macrophages. Finally we demonstrate that a three-month low-dose statin-rHDL treatment regimen inhibits plaque inflammation progression, while a one-week high-dose regimen markedly decreases inflammation in advanced atherosclerotic plaques. Statin-rHDL represents a novel potent atherosclerosis nanotherapy that directly affects plaque inflammation. PMID:24445279
Quantitative evaluation of lipid concentration in atherosclerotic plaque phantom by near-infrared multispectral angioscope at wavelengths around 1200 nm
Matsui, Daichi; Ishii, Katsunori; Awazu, Kunio
Atherosclerosis is a primary cause of critical ischemic diseases like heart infarction or stroke. A method that can provide detailed information about the stability of atherosclerotic plaques is required. We focused on spectroscopic techniques that could evaluate the chemical composition of lipid in plaques. A novel angioscope using multispectral imaging at wavelengths around 1200 nm for quantitative evaluation of atherosclerotic plaques was developed. The angioscope consists of a halogen lamp, an indium gallium arsenide (InGaAs) camera, 3 optical band pass filters transmitting wavelengths of 1150, 1200, and 1300 nm, an image fiber having 0.7 mm outer diameter, and an irradiation fiber which consists of 7 multimode fibers. Atherosclerotic plaque phantoms with 100, 60, 20 vol.% of lipid were prepared and measured by the multispectral angioscope. The acquired datasets were processed by spectral angle mapper (SAM) method. As a result, simulated plaque areas in atherosclerotic plaque phantoms that could not be detected by an angioscopic visible image could be clearly enhanced. In addition, quantitative evaluation of atherosclerotic plaque phantoms based on the lipid volume fractions was performed up to 20 vol.%. These results show the potential of a multispectral angioscope at wavelengths around 1200 nm for quantitative evaluation of the stability of atherosclerotic plaques.
The effect of serum MMP-9 and IL-6 on the vulnerability of carotid atherosclerotic plaque
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WANG Wei
Full Text Available Objective To explore the relationship of MMP-9 and IL-6 and the vulnerability of carotid atherosclerotic plaque. Methods According to the plaque vulnerability, 69 patients with acute cerebral infarction were divided into vulnerable plaque group (n = 35 and unvulnerable plaque group (n = 34. Twenty healthy subjects were selected as controls (control group. The levels of serum IL-6 and MMP-9 were examined. Results The level of MMP-9 and IL-6 in the unvulnerable plaque group was significantly higher than that in control group (P = 0.000, for all. The level of MMP-9 and IL-6 in the vulnerable plaque group was higher than that in the unvulnerable plaque group and control group (P = 0.000, for all. A positive correlation was observed between the expression of MMP-9 and IL-6 plaque (r = 0.836, P = 0.043. Conclusion MMP-9 and IL-6 are important factors for the promotion of vulnerable plaque. IL-6 may up-regulate the expression of MMP-9.
Nuclear medicine and coronary artery disease: evaluation of tracers of myocardial perfusion and vulnerable atherosclerotic plaque
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Coronary artery disease is one of the primary cause of mortality worldwide. Nuclear medicine is the major imaging technique for diagnosis and following of this disease. perfusion: nowadays, major radioactive agents used in clinical practice are myocardial perfusion tracers. The reference tracer is thallium-201. However, 201Tl presents some drawbacks. 99mTcn-noet has been proposed for its replacement. This study shows that in contrast with previous studies realized in vitro on cardio myocytes, verapamil, an l-type calcium channel inhibitor, does not inhibit myocardial fixation of 99mTcn-noet in vivo in dog. This data is in agreement with the hypothesis of a non specific endothelial fixation of this tracer. Moreover, this study shows that as a pure tracer of myocardial perfusion, 99mTcn-noet can also be used to assess myocardial viability on a model of myocardial chronic infarction in rat. atherosclerosis: disruption of vulnerable atherosclerotic plaques is the main event leading to coronary accidents. The second part of this study concerns the evaluation of new potential tracers of the vulnerable atherosclerotic plaque in an experimental model of rabbit with an inheritable hypercholesterolemia. The four tracers evaluated (b2702(r), b2702-I, b2702-Tc and Tc-raft-b2702) are synthetic peptides comprising the residues 75-84 of hla-b2702, a molecule known to link vcam-1, an adhesion molecule expressed in vulnerable atherosclerotic plaque. The autoradiography studies show that all tracers accumulate within atherosclerotic plaque expressing vcam- and that. i-b2702 shows the best plaque/control fixation ratio. (author)
Mechanical modeling of cholesterol crystallization in atherosclerotic plaques base on Micro-OCT images (Conference Presentation)
Luo, Yuemei; Liu, Xinyu; Chen, Si; Cui, Dongyao; Wang, Xianghong; Liu, Linbo
Plaque rupture is the critical cause of cardiovascular thrombosis but this process is still under discussion. Recent studies show that, during crystallization, cholesterol crystals in atheromatous plaques accumulate rapidly in a limited space and may result in plaque rupture. However, the actual role of cholesterol crystals on plaque rupture remains unclear due to the lack of detailed morphological information of cholesterol crystals. In this study, we used a Micro-optical coherence tomography (µOCT) setup with 1-2 µm spatial resolution to extract the geometry of cholesterol crystals from human atherosclerotic artery ex vivo firstly. With measured dimensions of cholesterol crystals by this µOCT system (the average length and thickness of 269.1±80.16 µm and 3.0±0.33 µm), we developed a two-dimensional mechanical model in which rectangular shaped cholesterol crystals distribute at different locations spatially. We predicted the stress on the thin cap induced by the expansion of cholesterol crystals by use of finite-element method. Since a large portion of plaques (58%) rupture at points of peak circumferential stress (PCS), we used PCS as the primary indicator of plaque stability with blood pressure of 14.6 kPa on the lumen. The results demonstrate that loading of the concentrated crystals especially at the cap shoulder destabilize the plaque by proportionally increasing the PCS, while evenly distributed crystals loading along the cap might impose less PCS to the plaque than the concentrated case.
Multislice CT characteristics of coronary atherosclerotic plaques in acute coronary syndrome
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Objective: To compare the plaque characteristics of acute coronary, syndrome (ACS) and stable angina (SA) by multislice CT(MSCT). Methods: MSCT images of 27 patients with ACS and SA were compared. Results: The frequency of positive vascular remodeling was significantly different in ACS (19/31) and SA (6/41, χ2=16.95, P2=8.00, P2=3.62, P<0.05). The mean CT value of non- calcified plaques in ACS [(35.0±15.1) HU] was lower than in SA [(67.5±26.5) HU(t=4.82,P< 0.01)]. Conclusion: The MSCT characteristics of atherosclerotic plaques in ACS include positive vascular remodeling, low plaque density, spotty calcification, and eccentric stenosis. (authors)
Quantitative Evaluation of the Polarization Characteristics of Coronary Arteries Atherosclerotic Plaques at Different Development Stages
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E.V. Gubarkova
Full Text Available The aim of the investigation was to develop an approach to quantitative evaluation of polarization properties (birefringence and cross-scattering basing on cross-polarization OCT images (CP OCT in order to characterize the development stages of atherosclerotic plaques and to reveal unstable ones. Materials and Methods. We report on quantitative analysis of CP OCT images of the seven development stages of atherosclerotic plaques ex vivo. Integral depolarization factor (IDF and effective birefringence coefficient (Δn were proposed as parameters for quantitative characterization of the CP OCT images. Results. Calculation of the IDF and Δn in the local region of interest (intima/fibrous cap showed a statistically relevant difference between stable (stage IV and unstable (stage Va plaques (0.46±0.21 against 0.09±0.04 for IDF and (0.47±0.10·10–3 against (0.25±0.07·10–3 for Δn; (p<0.05. It was found that Δn value in the range (0.22–0.29·10–3 (within the limits of two standard deviations indicates the presence of only a small amount of highly organized collagen in the fibrous cap of an unstable plaque which can indicate its tendency to rupture. We believe that these changes are connected with the prevalence of disorganized fibers during the inflammatory process in the fibrous cap of an unstable plaque, and to the presence of clusters of foam cells and inflammatory cells between them. Conclusion. The proposed approach to the quantitative evaluation of CP OCT images (calculation of IDF and building Δn maps allows to assess both cross-scattering and birefringence of atherosclerotic plaques at various development stages and more reliably reveal their vulnerability.
Laser ablation of human atherosclerotic plaque without adjacent tissue injury
Grundfest, W. S.; Litvack, F.; Forrester, J. S.; Goldenberg, T.; Swan, H. J. C.
Seventy samples of human cadaver atherosclerotic aorta were irradiated in vitro using a 308 nm xenon chloride excimer laser. Energy per pulse, pulse duration and frequency were varied. For comparison, 60 segments were also irradiated with an argon ion and an Nd:YAG laser operated in the continuous mode. Tissue was fixed in formalin, sectioned and examined microscopically. The Nd:YAG and argon ion-irradiated tissue exhibited a central crater with irregular edges and concentric zones of thermal and blast injury. In contrast, the excimer laser-irradiated tissue had narrow deep incisions with minimal or no thermal injury. These preliminary experiments indicate that the excimer laser vaporizes tissue in a manner different from that of the continuous wave Nd:YAG or argon ion laser. The sharp incision margins and minimal damage to adjacent normal tissue suggest that the excimer laser is more desirable for general surgical and intravascular uses than are the conventionally used medical lasers.
Tools for improving the diagnosis of atherosclerotic plaque using ultrasound
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Jespersen, Søren Kragh
topics have been investigated: an ultrasound pulse-echo simulation tool and a new compound imaging technique for improving visualization of atherosclerotic disease.A tool for simulation of the received electrical signal in a pulse-echo ultrasound system, due to a reflector surface of arbitrary geometry......, has been developed. The method is denoted the Diffraction Response Interpolation Method (DRIM) and is based on the pulse-echo diffraction impulse response method. The DRIM is a computationally efficient tool for calculating the integral of the spatially varying pulse-echo diffraction impulse response...... and experimentally. The MACI method operates by recording information about a given tissue region using a number of beam angles (typically 3 to 11) and combining the information into a single compound image (so-called spatial compounding). During the project a flexible experimental multi-channel ultrasound system...
Delivery of negatively charged liposomes into the atherosclerotic plaque of apolipoprotein E-deficient mouse aortic tissue
Zhaorigetu, Siqin; Rodriguez-Aguayo, Cristian; Sood, Anil K.; Lopez-Berestein, Gabriel; Walton, Brian L.
Liposomes have been used to diagnose and treat cancer and, to a lesser extent, cardiovascular disease. We previously showed the uptake of anionic liposomes into the atheromas of Watanabe heritable hyperlipidemic rabbits within lipid pools. However, the cellular distribution of anionic liposomes in atherosclerotic plaque remains undescribed. In addition, how anionic liposomes are absorbed into atherosclerotic plaque is unclear. We investigated the uptake and distribution of anionic liposomes i...
Prevalence of Foam Cells and Helper-T cells in Atherosclerotic Plaques of Korean Patients with Carotid Atheroma
Lee, Won-Ha; Ko, Young-Hyeh; Kim, Dong-Ik; Lee, Byung-Boong; Park, Jeong-Euy
Background Inflammation and activation of immune cells have important roles in the pathogenesis of atherosclerosis. We analyzed the involvement of various immune cells in the pathogenesis of atherosclerosis. Methods We investigated the presence of foam cells, lymphocytes and killer cells in 11 atherosclerotic plaque specimens removed from Korean patients who underwent carotid endoarterectomy. Atherosclerotic plaques were analyzed by immunohistochemistry using monoclonal antibody specific to f...
Associations of Biomarkers of Atherosclerotic Plaques Instability (MMP-9, TIMP-1 and Zinc Levels in Carotid Atherosclerosis
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Gulnora A. Rozikhodjaeva
Full Text Available The levels of matrix metalloproteinase-9 (MMP-9 and its tissue inhibitor (TIMP-1 in serum, and the concentration of Zn in the serum, hair and carotid atherosclerotic plaques were examined. The relationships zinc-dependent endopeptidases as biomarkers instability of atherosclerotic plaques and zinc in patients with carotid atherosclerosis were studied. The results contribute to the selection of patients at high risk for cardiovascular events.
Selective expansion of influenza A virus-specific T cells in symptomatic human carotid artery atherosclerotic plaques
Keller, Tymen; Meer, Jelger; Teeling, Peter; Sluijs, Koenraad; Idu, Mirza; Rimmelzwaan, Guus; Levi, Michael; Wal, Allard; Boer, Onno
textabstractBACKGROUND AND PURPOSE - Evidence is accumulating that infection with influenza A virus contributes to atherothrombotic disease. Vaccination against influenza decreases the risk of atherosclerotic syndromes, indicating that inflammatory mechanisms may be involved. We tested the hypothesis that influenza A virus-specific T cells contribute to atherosclerotic plaque inflammation, which mediates the onset of plaque rupture. METHODS - T-cell cultures were generated from atheroscleroti...
Effect of Aerobic Exercise and Dietary Fat on the Formation of Atherosclerotic Plaque in ApoE-Deficient Mice%有氧运动和膳食脂肪对ApoE基因缺陷小鼠动脉粥样硬化斑块形成的影响
Institute of Scientific and Technical Information of China (English)
陈近利; 陈吉棣
为了探讨有氧运动和膳食因素在动脉粥样硬化斑块形成过程中的作用,研究了在跑台上进行的有氧运动和低脂膳食对ApoE基因缺陷小鼠动脉粥样硬化斑块形成过程的影响。结果表明:10周中等强度的有氧运动组和低脂膳食组ApoE基因缺陷小鼠主动脉窦处形成的动脉粥样硬化斑块面积均较对照组减少(P<0.05);有氧运动结合低脂膳食组ApoE基因缺陷小鼠的斑块面积分别低于单独的运动组和低脂膳食组(P<0.05)。研究提示有氧运动和低脂膳食均有利于并有效减轻动脉粥样硬化斑块的形成,有氧运动和低脂膳食两种因素结合的作用大于单独的有氧运动和低脂膳食的作用,二者在预防动脉粥样硬化斑块的形成上可能存在协同加强作用。%To approach the effects of aerobic exercise anddietary fat on the formation of atherosclerotic plaque, we have adopted the ApoE-gene knockout mice as the model to study the effects on an animal treadmill. The results show that the plaque area at the aortic sinuses of the exercised and low fat diet fed mice group were significantly reduced as comparing with the control group respectively. Mice of aerobic exercise and low fat diet combined treated group have the least lesion area of plaque as compared with the other groups. These results have indicated that either aerobic exercise or low fat diet is beneficial and effective to alleviate the formation of atherosclerotic lesions. However, aerobic combined with exercise can provide the greatest benefit in the alleviation of the formation of atherosclerotic plaque as compared with the single factor of either exercise or low fat diet.
Evaluating intensity normalization for multispectral classification of carotid atherosclerotic plaque
Gao, Shan; van't Klooster, Ronald; van Wijk, Diederik F.; Nederveen, Aart J.; Lelieveldt, Boudewijn P. F.; van der Geest, Rob J.
Intensity normalization is an important preprocessing step for automatic plaque analysis in MR images as most segmentation algorithms require the images to have a standardized intensity range. In this study, we derived several intensity normalization approaches with inspiration from expert manual analysis protocols, for classification of carotid vessel wall plaque from in vivo multispectral MRI. We investigated intensity normalization based on a circular region centered at lumen (nCircle); based on sternocleidomastoid muscle (nSCM); based on intensity scaling (nScaling); based on manually classified fibrous tissue (nManuFibrous) and based on automatic classified fibrous tissue (nAutoFibrous). The proposed normalization methods were evaluated using three metrics: (1) Dice similarity coefficient (DSC) between manual and automatic segmentation obtained by classifiers using different normalizations; (2) correlation between proposed normalizations and normalization used by expert; (3) Mahalanobis Distance between pairs of components. In the performed classification experiments, features of normalized image, smoothed, gradient magnitude and Laplacian images at multi-scales, distance to lumen, distance to outer wall, wall thickness were calculated for each vessel wall (VW) pixel. A supervised pattern recognition system, based on a linear discriminate classifier, was trained using the manual segmentation result to classify each VW pixel to be one of the four classes: fibrous tissue, lipid, calcification, and loose matrix according to the highest posterior probability. We evaluated our method on image data of 23 patients. Compared to the result of conventional square region based intensity normalizatio n, nScaling resulted in significant increase in DSC for lipid (p = 0.006) and nAutoFibrous resulted in significant increase in DSC for calcification (p = 0.004). In conclusion, it was demonstrated that the conventional region based normalization approach is not optimal and n
Vitamin K-antagonists accelerate atherosclerotic calcification and induce a vulnerable plaque phenotype.
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Leon J Schurgers
Full Text Available BACKGROUND: Vitamin K-antagonists (VKA are treatment of choice and standard care for patients with venous thrombosis and thromboembolic risk. In experimental animal models as well as humans, VKA have been shown to promote medial elastocalcinosis. As vascular calcification is considered an independent risk factor for plaque instability, we here investigated the effect of VKA on coronary calcification in patients and on calcification of atherosclerotic plaques in the ApoE(-/- model of atherosclerosis. METHODOLOGY/PRINCIPAL FINDINGS: A total of 266 patients (133 VKA users and 133 gender and Framingham Risk Score matched non-VKA users underwent 64-slice MDCT to assess the degree of coronary artery disease (CAD. VKA-users developed significantly more calcified coronary plaques as compared to non-VKA users. ApoE(-/- mice (10 weeks received a Western type diet (WTD for 12 weeks, after which mice were fed a WTD supplemented with vitamin K(1 (VK(1, 1.5 mg/g or vitamin K(1 and warfarin (VK(1&W; 1.5 mg/g & 3.0 mg/g for 1 or 4 weeks, after which mice were sacrificed. Warfarin significantly increased frequency and extent of vascular calcification. Also, plaque calcification comprised microcalcification of the intimal layer. Furthermore, warfarin treatment decreased plaque expression of calcification regulatory protein carboxylated matrix Gla-protein, increased apoptosis and, surprisingly outward plaque remodeling, without affecting overall plaque burden. CONCLUSIONS/SIGNIFICANCE: VKA use is associated with coronary artery plaque calcification in patients with suspected CAD and causes changes in plaque morphology with features of plaque vulnerability in ApoE(-/- mice. Our findings underscore the need for alternative anticoagulants that do not interfere with the vitamin K cycle.
Magnetic resonance imaging features of vulnerable plaques in an atherosclerotic rabbit model
Institute of Scientific and Technical Information of China (English)
ZHAO Xue-cheng; ZHAO Quan-ming; MA Xiao-hai; ZENG Cong-he; FENG Ting-ting; ZHAO Xin; ZHANG Zhao-qi
Background Noninvasive detection of vulnerable plaque has a significant implication for prevention and treatment of atherosclerotic diseases.The aim of this study is to investigate the difference between vulnerable plaques and stable plaques in magnetic resonance (MR) images.Methods Atherosclerosis was induced in twenty male New Zealand white rabbits by high cholesterol diet and balloon injury of the abdominal aorta.After baseline (pre-triggering) MR imaging (MRI) scan,the rabbits underwent pharmaceutical triggering with Russell's viper venom and histamine to induce atherothrombosis,followed by another MRI scan 48 hours later (post-triggering).Rabbits were euthanized to obtain pathological and histological data.The results of MRI were compared with those of pathology and histology.Results MRI showed that abdominal aorta of the rabbits had pathological change of atherosclerosis in different degrees.Seventy-five plaques were analysed,among which 14 had vulnerable thrombi and 61 stable.Thrombosis was identified in 7 of 11 rabbits by post-triggering MRI,the sensitivity and K value of MR in detection of vulnerable plaque was 71% and 0.803 (P <0.05).MRI data significantly correlated with the histopathological data in fibrous cap thickness (t=0.749) plaque area (r=0.853),lipid core area (r=0.900).Compared with stable plaques,vulnerable plaques had a significantly thinner fibrous cap ((0.58+0.27) mm vs.(0.95+0.22) mm),larger lipid core area ((7.56+2.78) mm2 vs.(3.29+1.75) mm2),and a higher ratio of lipid core area/plaque area ((55+16)% vs.(27±17)%),but plaque area was comparable in two groups on MRI.The ratio of lipid core area/plaque area was a strong predictor of vulnerable plaques.Conclusion MRI could distinguish vulnerable plaques from stable plaques in a rabbit model of atherothrombosis and may thus be useful as a noninvasive modality for detection of vulnerable plaques in humans.
Evaluation of radiotracers for the detection of atherosclerotic vulnerable plaque and myocardial angiogenesis
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Cardiovascular diseases are the leading cause of mortality worldwide. Coronary events are mainly caused by coronary plaque rupture or erosion. However, at present, there is no noninvasive tool available for the detection of vulnerable plaques. The first part of thesis is about evaluation of new radiotracers for the detection of atherosclerotic vulnerable plaques. 99mTc-B2702p, 20 derivatives, 99mTc-VP and 99mTc-VINP28 were evaluated in an experimental model of atherosclerosis (ApoE-/- mice with left carotid artery ligation). 99mTc- B2702p1 is a potentially useful radiotracer for the in vivo molecular imaging of VCAM-1 expression in atherosclerotic plaques. Myocardial angiogenesis is an important post infarction phenomenon. Angiogenic therapy improves experimentally cardiac parameters. However, clinical trials using the same therapy are more controversial. At present, clinical imaging tools don't allow us to assess angiogenesis therapy. The second part of thesis is about validation of 99mTc-RAFT-RGD in the detection of myocardial angiogenesis. 99mTc-RAFT-RGD allow us to perform noninvasive molecular imaging of myocardial angiogenesis in an experimental model. (author)
IVUS-based histology of atherosclerotic plaques: improving longitudinal resolution
Taki, Arash; Pauly, Olivier; Setarehdan, S. Kamaledin; Unal, Gozde; Navab, Nassir
Although Virtual Histology (VH) is the in-vivo gold standard for atherosclerosis plaque characterization in IVUS images, it suffers from a poor longitudinal resolution due to ECG-gating. In this paper, we propose an image-based approach to overcome this limitation. Since each tissue have different echogenic characteristics, they show in IVUS images different local frequency components. By using Redundant Wavelet Packet Transform (RWPT), IVUS images are decomposed in multiple sub-band images. To encode the textural statistics of each resulting image, run-length features are extracted from the neighborhood centered on each pixel. To provide the best discrimination power according to these features, relevant sub-bands are selected by using Local Discriminant Bases (LDB) algorithm in combination with Fisher's criterion. A structure of weighted multi-class SVM permits the classification of the extracted feature vectors into three tissue classes, namely fibro-fatty, necrotic core and dense calcified tissues. Results shows the superiority of our approach with an overall accuracy of 72% in comparison to methods based on Local Binary Pattern and Co-occurrence, which respectively give accuracy rates of 70% and 71%.
Association of carotid atherosclerotic plaque features with acute ischemic stroke: A magnetic resonance imaging study
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Zhao, Huilin [Department of Radiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127 (China); Zhao, Xihai [Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing 100084 (China); Liu, Xiaosheng; Cao, Ye [Department of Radiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127 (China); Hippe, Daniel S.; Sun, Jie [Department of Radiology, University of Washington, Seattle, WA 98109 (United States); Li, Feiyu [Department of Radiology, Peking University First Hospital, Beijing 100034 (China); Xu, Jianrong, E-mail: firstname.lastname@example.com [Department of Radiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127 (China); Yuan, Chun [Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing 100084 (China); Department of Radiology, University of Washington, Seattle, WA 98109 (United States)
Background and purpose: It remains unclear whether direct vessel wall imaging can identify carotid high-risk lesions in symptomatic subjects and whether carotid plaque characteristics are more effective indicators for cerebral infarct severity than stenosis. This study sought to determine the associations of carotid plaque characteristics by MR imaging with stenosis and acute cerebral infarct (ACI) sizes on diffusion weighted imaging (DWI). Materials and methods: One hundred and fourteen symptomatic patients underwent carotid and brain MRI. ACI volume was determined from symptomatic internal carotid artery territory on DWI images. Ipsilateral carotid plaque morphological and compositional characteristics, and stenosis were also determined. The relationships between carotid plaque characteristics, stenosis and ACIs size were then evaluated. Results: In carotid arteries with 30–49% stenosis, 86.7% and 26.7% were found to have lipid-rich necrotic core (LRNC) and intraplaque hemorrhage, respectively. Furthermore, 45.8% of carotid arteries with 0–29% stenosis developed LRNCs. Carotid morphological measurements, such as % wall volume, and the LRNC size were significantly associated with ipsilateral ACIs volume before and after adjustment for significant demographic factors (age and LDL) or stenosis in patients with carotid plaque (all p < 0.05). Conclusions: A substantial number of high-risk plaques characterized by vessel wall imaging exist in carotid arteries with lower grade stenosis. In addition, carotid plaque characteristics, particularly the % wall volume and LRNC size, are independently associated with cerebral infarction as measured by DWI lesions. Our findings indicate that characterizing atherosclerotic plaque by MR vessel wall imaging might be useful for stratification of plaque risk and infarction severity.
MRI-based Biomechanical Modeling of Carotid Atherosclerotic Plaques: The stable plaque paradigm
Nieuwstadt, Harm
markdownabstract__Abstract__ Carotid atherosclerosis is a common cause of acute ischemic stroke and places a major burden on worldwide health-related quality of life. The currently-used stenosis-degree guidelines to decide on surgical intervention through carotid endarterectomy in order to prevent a future event are imperfect. This is because they insufficiently target plaque vulnerability. To provide an alternative carotid plaque vulnerability assessment, one can compute the biomechanical pe...
Relationship between interleukin-18 levels and characterization of atherosclerotic plaque and percutaneous coronary intervention
Institute of Scientific and Technical Information of China (English)
Weihua Li; Kaimin Lin; Lei Gao; Rong Wu; Qiang Xie; Yongjun Guo; Shuhui Dai
Background lnterleuldn-18(IL- 18) plays a key role in the development,progression and outcome of coronary artery disease and its complications.However,its variability relation to the characterization of atherosclerotic plaque and percutaneous coronary intervention are still unknown.Methods Fifty four patients with coronary artery disease [22 patients with stable angina (SA) and 32 patients with acute coronary syndrome (ACS)] were enrolled in this study.All patients underwent percutaneous coronary intervention (PCI).The stability of the plaques at the criminal vessels was assessed with analogical IVUS.Serum IL-18 levels were measured at the time points of 5 rain before PCI,and Oh,6h,24h and lmonth after PCI in all patients.Results ACS group consisted mainly of lipidic unstable plaques while SA group of fibrous stable plaques.Moreover,compared with those in SA group,eccentricity index (EI) and remodeling index (RI) were significantly higher in ACS group.Positive remodeling was seen in ACS group while negative or no remodeling in SA group.Further,serum IL-18 levels were significantly elevated in patients with ACS than those in SA group before PCI,increased at Oh,6h,24h after PCI (P<0.05)and were not significant different at 1 month after PCI from those before PCI.Conclusions There is significant difference in the composition and structural characteristics of atherosclerotic plaques between ACS and UA groups.PCI triggersd and enhances the inflammatory response in a short time.Serum levels of IL- 18 are the predictors of progression of unstable plaque in atherosclerosis.Post-operative complications of PCI might be reduced by inhibiting IL- 18.(J Geriatr Cardiol 2008;5:21-24)
Alternation of histone and DNA methylation in human atherosclerotic carotid plaques.
Greißel, A; Culmes, M; Napieralski, R; Wagner, E; Gebhard, H; Schmitt, M; Zimmermann, A; Eckstein, H-H; Zernecke, A; Pelisek, J
Little is known about epigenetics and its possible role in atherosclerosis. We here analysed histone and DNA methylation and the expression of corresponding methyltransferases in early and advanced human atherosclerotic carotid lesions in comparison to healthy carotid arteries. Western Blotting was performed on carotid plaques from our biobank with early (n=60) or advanced (n=60) stages of atherosclerosis and healthy carotid arteries (n=12) to analyse di-methylation patterns of histone H3 at positions K4, K9 and K27. In atherosclerotic lesions, di-methylation of H3K4 was unaltered and that of H3K9 and H3K27 significantly decreased compared to control arteries. Immunohistochemistry revealed an increased appearance of di-methylated H3K4 in smooth muscle cells (SMCs), a decreased expression of di-methylated H3K9 in SMCs and inflammatory cells, and reduced di-methylated H3K27 in inflammatory cells in advanced versus early atherosclerosis. Expression of corresponding histone methyltransferases MLL2 and G9a was increased in advanced versus early atherosclerosis. Genomic DNA hypomethylation, as determined by PCR for methylated LINE1 and SAT-alpha, was observed in early and advanced plaques compared to control arteries and in cell-free serum of patients with high-grade carotid stenosis compared to healthy volunteers. In contrast, no differences in DNA methylation were observed in blood cells. Expression of DNA-methyltransferase DNMT1 was reduced in atherosclerotic plaques versus controls, DNMT3A was undetectable, and DNMT3B not altered. DNA-demethylase TET1 was increased in atherosclerosisc plaques. The extent of histone and DNA methylation and expression of some corresponding methyltransferases are significantly altered in atherosclerosis, suggesting a possible contribution of epigenetics in disease development. PMID:25993995
Ex vivo identification of atherosclerotic plaque calcification by a 31P solid-state magnetic resonance imaging technique.
Hallock, Kevin J; Hamilton, James A
Calcified tissue is a common component of atherosclerotic plaques, and occurs most often in mature plaques. The process of calcification is a poorly understood risk factor that may contribute to a plaque's vulnerability to sudden rupture. In this study a solid-state imaging sequence, termed single-point imaging (SPI), was used to observe calcification directly in ex vivo atherosclerotic plaques. Standards were used to validate the ability of (31)P SPI to detect and differentiate calcification from crystalline cholesterol, phospholipids, and other plaque components. After suitable experimental parameters were found, human carotid specimens obtained by endarterectomy were imaged ex vivo by (31)P solid-state imaging and standard (1)H methods. In contrast to (1)H imaging methods, (31)P imaging detected only the calcification in the plaque. PMID:17089379
The Role of Septal Perforators and "Myocardial Bridging Effect" in Atherosclerotic Plaque Distribution in the Coronary Artery Disease
Wasilewski, Jarosław; Roleder, Marcin; Niedziela, Jacek; Nowakowski, Andrzej; Osadnik, Tadeusz; Głowacki, Jan; Mirota, Kryspin; Poloński, Lech
Summary The distribution of atherosclerotic plaque burden in the human coronary arteries is not uniform. Plaques are located mostly in the left anterior descending artery (LAD), then in the right coronary artery (RCA), circumflex branch (LCx) and the left main coronary artery (LM) in a decreasing order of frequency. In the LAD and LCx, plaques tend to cluster within the proximal segment, while in the RCA their distribution is more uniform. Several factors have been involved in this phenomenon...
Digital Image Analysis of Ultrasound B-mode images of Carotid Atherosclerotic Plaque: Correlation with Histological Examination
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Wilhjelm, Jens E.; Rosendal, Kim; Grønholdt, Marie-Louise Moes; Jespersen, Søren Kragh; Hansen, Lars Kai; Sillesen, Henrik
This paper reports on a study of how well texture features extracted from B-mode images of atherosclerotic plaque correlates with histological results obtained from the same plaque after carotid endarterectomy. The study reveals that a few second order texture features (diagonal moment, standard...... deviation and autocorrelation) provide good correlation within the training set (p = 0.04); However, the correlation found so far is not so high, that the method can be used in clinical prediction of plaque constituents....
Fluorescence imaging of macrophages in atherosclerotic plaques using plasmonic gold nanorose
Wang, Tianyi; Sapozhnikova, Veronika; Mancuso, J. Jacob; Willsey, Brian; Qiu, Jinze; Ma, Li L.; Li, Xiankai; Johnston, Keith P.; Feldman, Marc D.; Milner, Thomas E.
Macrophages are one of the most important cell types involved in the progression of atherosclerosis which can lead to myocardial infarction. To detect macrophages in atherosclerotic plaques, plasmonic gold nanorose is introduced as a nontoxic contrast agent for fluorescence imaging. We report macrophage cell culture and ex vivo tissue studies to visualize macrophages targeted by nanorose using scanning confocal microscopy. Atherosclerotic lesions were created in the aorta of a New Zealand white rabbit model subjected to a high cholesterol diet and double balloon injury. The rabbit was injected with nanoroses coated with dextran. A HeNe laser at 633 nm was used as an excitation light source and a acousto-optical beam splitter was utilized to collect fluorescence emission in 650-760 nm spectral range. Results of scanning confocal microscopy of macrophage cell culture and ex vivo tissue showed that nanoroses produce a strong fluorescence signal. The presence of nanorose in ex vivo tissue was further confirmed by photothermal wave imaging. These results suggest that scanning confocal microscopy can identify the presence and location of nanorose-loaded macrophages in atherosclerotic plaques.
Wall shear stress as a stimulus for carotid atherosclerotic plaque progression: An MRI-based CFD pilot study
Canton, Gador; Chiu, Bernard; Hatsukami, Tom; Kerwin, William; Yuan, Chun
The aim of this study was to explore the hypothesis that intra-plaque hemorrhage, a feature associated with adverse outcomes and atherosclerotic plaque progression and destabilization, is more likely to occur in plaques with elevated levels of wall shear stress (WSS). We used multi-sequence in-vivo magnetic resonance imaging (MRI) to characterize ten human carotid atherosclerotic plaques and an MRI-based computational fluid dynamics (CFD) model to solve the equations governing the blood flow. Hemorrhage was detected within the necrotic core (intra-plaque hemorrhage) in five of these ten cases. WSS data were extracted from the results of the CFD simulations to compare patterns between the cases with and without hemorrhage. We computed the mean value of the WSS (for each time point of the cardiac cycle) at the region where a necrotic core was detected. The results from this pilot study indicate a possible link between the presence of hemorrhage within a lipid-rich necrotic core in human carotid atherosclerotic plaques and elevated levels of shear stress force acting on the luminal surface. Thus, elevated wall shear stress may be used as a high risk feature in advanced carotid atherosclerotic plaques.
Atorvastatin attenuates atherosclerotic plaque destabilization by inhibiting endoplasmic reticulum stress in hyperhomocysteinemic mice.
Jia, Fang; Wu, Chunfang; Chen, Zhenyue; Lu, Guoping; Sun, Jianhui
Endoplasmic reticulum (ER) stress has been suggested to play a role in the progression of plaque vulnerability and the occurrence of acute complications of coronary atherosclerosis. Atorvastatin is known to exert pleiotropic effects on the cardiovascular system. The present study aimed to examine the stabilizing effects of atorvastatin on vulnerable plaques within hyperhomocysteinemic apolipoprotein E‑deficient (ApoE‑/‑) mice, and to investigate the potential mechanisms underlying ER stress in ApoE‑/‑ mice and macrophages. In the present study, ApoE‑/‑ mice were administrated methionine or atorvastatin, and were sacrificed after 2 months. Necrotic core size, collagen content and inflammatory cytokine infiltration were subsequently measured in the aortic lesions, in order to investigate plaque stability. Treatment with atorvastatin decreased the number and size of necrotic cores, increased collagen content, and downregulated tumor necrosis factor (TNF)‑α and matrix metalloproteinase (MMP)‑9 mRNA expression, as compared with the methionine group. Immunohistochemical analysis indicated that atorvastatin administration prevented ER stress activation in aortic lesions of hyperhomocysteinemic mice. Furthermore, macrophages were challenged with homocysteine (Hcy) in the presence or absence of atorvastatin and thapsigargin (an ER stress inducer). Atorvastatin suppressed Hcy‑induced ER stress, and downregulated TNF‑α and MMP‑9 mRNA expression in the macrophages. Conversely, thapsigargin attenuated the inhibitory effects of atorvastatin against Hcy‑induced TNF‑α and MMP‑9 expression. These results indicated that hyperhomocysteinemia may promote atherosclerotic plaque development and instability. In addition, atorvastatin was able to improve atherosclerotic plaque stability in hyperhomocysteinemic mice by inhibiting ER stress. PMID:26956896
PET Imaging of Atherosclerotic Disease: Advancing Plaque Assessment from Anatomy to Pathophysiology.
Evans, Nicholas R; Tarkin, Jason M; Chowdhury, Mohammed M; Warburton, Elizabeth A; Rudd, James H F
Atherosclerosis is a leading cause of morbidity and mortality. It is now widely recognized that the disease is more than simply a flow-limiting process and that the atheromatous plaque represents a nidus for inflammation with a consequent risk of plaque rupture and atherothrombosis, leading to myocardial infarction or stroke. However, widely used conventional clinical imaging techniques remain anatomically focused, assessing only the degree of arterial stenosis caused by plaques. Positron emission tomography (PET) has allowed the metabolic processes within the plaque to be detected and quantified directly. The increasing armory of radiotracers has facilitated the imaging of distinct metabolic aspects of atherogenesis and plaque destabilization, including macrophage-mediated inflammatory change, hypoxia, and microcalcification. This imaging modality has not only furthered our understanding of the disease process in vivo with new insights into mechanisms but has also been utilized as a non-invasive endpoint measure in the development of novel treatments for atherosclerotic disease. This review provides grounding in the principles of PET imaging of atherosclerosis, the radioligands in use and in development, its research and clinical applications, and future developments for the field. PMID:27108163
Comparison between Adventitial and Intimal Inflammation of Ruptured and Nonruptured Atherosclerotic Plaques in Human Coronary Arteries
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Higuchi Maria L.
Full Text Available OBJECTIVE: To verify the possible role of adventitial inflammation in atherosclerotic plaque vulnerability and coronary artery remodelling. METHODS: We compared the mean numbers of lymphocytes in the adventitia and in the plaque of ruptured thrombosed and stable equi-stenotic coronary segments of 34 patients who died due to acute myocardial infarction. We also analysed adventitial microvessels, adventitial fibrosis and the external elastic membrane. RESULTS: In the adventitia, the numbers of lymphocytes and microvessels/mm² were 69.5±88.3 and 60.9± 32.1 in culprit lesions and 16.4 ± 21.1 and 44.3±16.1 in stable lesions (p<0.05; within the plaques, the mean number of lymphocytes was 24±40.8 in culprit lesions and 10.9±13.2 in stable ones (p=0.17. The mean percent area of adventitial fibrosis/cross-sectional area of the vessel was significantly lower in unstable plaques (p<0.001. The confocal images showed holes in the external elastic membrane. CONCLUSION: Unstable plaques exhibit chronic pan-arteritis, accompanied by enlargement, medial thinning, and less fibrosis than in stable lesions, which is compatible with vessel aneurysm. Adventitial inflammation may contribute significantly to atheroma instability.
Echolucency of computerized ultrasound images of carotid atherosclerotic plaques are associated with increased levels of triglyceride-rich lipoproteins as well as increased plaque lipid content
DEFF Research Database (Denmark)
Grønholdt, Marie-Louise M.; Nordestgaard, Børge; Wiebe, Britt M.; Wilhjelm, Jens Erik; Sillesen, Henrik
Background-Echo-lucency of carotid atherosclerotic plaques on computerized ultrasound B-mode images has been associated with a high incidence of brain infarcts as evaluated on CT scans. We tested the hypotheses that triglyceride-rich lipoproteins in the fasting and postprandial state predict......-rich lipoproteins predict echo-lucency of carotid plaques, which is associated with increased plaque Lipid content, Because echo-lucency has been associated with a high incidence of brain infarcts on CT scans, triglyceride-rich lipoproteins may predict a plaque type particularly vulnerable to rupture....
Smooth muscle cells healing atherosclerotic plaque disruptions are of local, not blood, origin in apolipoprotein E knockout mice
DEFF Research Database (Denmark)
Bentzon, Jacob F; Sondergaard, Claus S; Kassem, Mustafa;
circulating bone marrow-derived progenitor cells. Here, we analyzed the contribution of this mechanism to plaque healing after spontaneous and mechanical plaque disruption in apolipoprotein E knockout (apoE-/-) mice. METHODS AND RESULTS: To determine the origin of SMCs after spontaneous plaque disruption......GFP+ SMCs were detected. To examine the origin of healing SMCs in a model that recapitulates more features of human plaque rupture and healing, we developed a mechanical technique that produced consistent plaque disruption, superimposed thrombosis, and SMC-mediated plaque healing in apoE-/- mice. Mechanical...... originating from outside the local arterial segment were detected in healed plaques. CONCLUSIONS: Healing SMCs after atherosclerotic plaque disruption are derived entirely from the local arterial wall and not circulating progenitor cells in apoE-/- mice. Udgivelsesdato: 2007-Oct-30...
An integrated system for the segmentation of atherosclerotic carotid plaque ultrasound video.
Loizou, Christos; Petroudi, Styliani; Pantziaris, Marios; Nicolaides, Andrew; Pattichis, Constantinos
The robust border identification of atherosclerotic carotid plaque, the corresponding degree of stenosis of the common carotid artery (CCA), and also the characteristics of the arterial wall, including plaque size, composition, and elasticity, have significant clinical relevance for the assessment of future cardiovascular events. To facilitate the follow-up and analysis of the carotid stenosis in serial clinical investigations, we propose and evaluate an integrated system for the segmentation of atherosclerotic carotid plaque in ultrasound videos of the CCA based on video frame normalization, speckle reduction filtering, M-mode state-based identification, parametric active contours, and snake segmentation. Initially, the cardiac cycle in each video is identified and the video M-mode is generated, thus identifying systolic and diastolic states. The video is then segmented for a time period of at least one full cardiac cycle. The algorithm is initialized in the first video frame of the cardiac cycle, with human assistance if needed, and the moving atherosclerotic plaque borders are tracked and segmented in the subsequent frames. Two different initialization methods are investigated in which initial contours are estimated every 20 video frames. In the first initialization method, the initial snake contour is estimated using morphology operators; in the second initialization method, the Chan-Vese active contour model is used. The performance of the algorithm is evaluated on 43 real CCA digitized videos from B-mode longitudinal ultrasound segments and is compared with the manual segmentations of an expert, available every 20 frames in a time span of 3 to 5 s, covering, in general, 2 cardiac cycles. The segmentation results were very satisfactory, according to the expert objective evaluation, for the two different methods investigated, with true-negative fractions (TNF-specificity) of 83.7 ± 7.6% and 84.3 ± 7.5%; true-positive fractions (TPF-sensitivity) of 85.42 ± 8
Regulation and splicing of scavenger receptor class B type I in human macrophages and atherosclerotic plaques
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Fagerberg Björn
Full Text Available Abstract Background The protective role of high-density lipoprotein (HDL in the cardiovascular system is related to its role in the reverse transport of cholesterol from the arterial wall to the liver for subsequent excretion via the bile. Scavenger receptor class B type I (SR-BI binds HDL and mediates selective uptake of cholesterol ester and cellular efflux of cholesterol to HDL. The role of SR-BI in atherosclerosis has been well established in murine models but it remains unclear whether SR-BI plays an equally important role in atherosclerosis in humans. The aim of this study was to investigate the expression of SR-BI and its isoforms in human macrophages and atherosclerotic plaques. Methods The effect of hypoxia and minimally modified low-density lipoprotein (mmLDL, two proatherogenic stimuli, on SR-BI expression was studied in human monocyte-derived macrophages from healthy subjects using real-time PCR. In addition, SR-BI expression was determined in macrophages obtained from subjects with atherosclerosis (n = 15 and healthy controls (n = 15. Expression of SR-BI isoforms was characterized in human atherosclerotic plaques and macrophages using RT-PCR and DNA sequencing. Results SR-BI expression was decreased in macrophages after hypoxia (p Conclusion We conclude that SR-BI is regulated by proatherogenic stimuli in humans. However, we found no differences between subjects with atherosclerosis and healthy controls. This indicates that altered SR-BI expression is not a common cause of atherosclerosis. In addition, we identified SR-BIII as a novel isoform expressed in human macrophages and in human atherosclerotic plaques.
Assessment of 320-slice computed tomography angiography in distinguishing hemorrhage in carotid atherosclerotic plaques
Zhang, Xiao-Jie; Yu, Wei; Tao BI; Zi-xu YAN; Feng-ru SHI; SUN, Li-yuan; Zhao-qi ZHANG
Objective To assess the value of 320⁃slice computed tomography angiography (CTA) in distinguishing hemorrhage/thrombus from lipid-rich necrotic core (LRNC) in atherosclerotic plaques of carotid artery. Methods Thirty-seven subjects who prepared to perform carotid endarterectomy (CEA), with stenosis rate about 50%-99% in at least unilateral carotid artery detected by ultrasound, were enrolled in this study. Both 320-slice CTA and 3.0T high-resolution MRI were conducted within one week before o...
Meshless Generalized Finite Difference Method and Human Carotid Atherosclerotic Plaque Progression Simulation Using Multi-Year MRI Patient-Tracking Data
Yang, Chun; Tang, Dalin; Yuan, Chun; Kerwin, William; Liu, Fei; Canton, Gador; Hatsukami, Thomas S.; Atluri, Satya
Atherosclerotic plaque rupture and progression have been the focus of intensive investigations in recent years. Plaque rupture is closely related to most severe cardiovascular syndromes such as heart attack and stroke. A computational procedure based on meshless generalized finite difference (MGFD) method and serial magnetic resonance imaging (MRI) data was introduced to quantify patient-specific carotid atherosclerotic plaque growth functions and simulate plaque progression. Participating pa...
Mathematical modelling of atheroma plaque formation and development in coronary arteries
Cilla, Myriam; Peña, Estefanía; Martínez, Miguel A
Atherosclerosis is a vascular disease caused by inflammation of the arterial wall, which results in the accumulation of low-density lipoprotein (LDL) cholesterol, monocytes, macrophages and fat-laden foam cells at the place of the inflammation. This process is commonly referred to as plaque formation. The evolution of the atherosclerosis disease, and in particular the influence of wall shear stress on the growth of atherosclerotic plaques, is still a poorly understood phenomenon. This work pr...
Gene expression levels of matrix metalloproteinases in human atherosclerotic plaques and evaluation of radiolabeled inhibitors as imaging agents for plaque vulnerability
International Nuclear Information System (INIS)
Introduction: Atherosclerotic plaque rupture is the primary cause for myocardial infarction and stroke. During plaque progression macrophages and mast cells secrete matrix-degrading proteolytic enzymes, such as matrix metalloproteinases (MMPs). We studied levels of MMPs and tissue inhibitor of metalloproteinases-3 (TIMP-3) in relation to the characteristics of carotid plaques. We evaluated in vitro two radiolabeled probes targeting active MMPs towards non-invasive imaging of rupture-prone plaques. Methods: Human carotid plaques obtained from endarterectomy were classified into stable and vulnerable by visual and histological analysis. MMP-1, MMP-2, MMP-8, MMP-9, MMP-10, MMP-12, MMP-14, TIMP-3, and CD68 levels were investigated by quantitative polymerase chain reaction. Immunohistochemistry was used to localize MMP-2 and MMP-9 with respect to CD68-expressing macrophages. Western blotting was applied to detect their active forms. A fluorine-18-labeled MMP-2/MMP-9 inhibitor and a tritiated selective MMP-9 inhibitor were evaluated by in vitro autoradiography as potential lead structures for non-invasive imaging. Results: Gene expression levels of all MMPs and CD68 were elevated in plaques. MMP-1, MMP-9, MMP-12 and MMP-14 were significantly higher in vulnerable than stable plaques. TIMP-3 expression was highest in stable and low in vulnerable plaques. Immunohistochemistry revealed intensive staining of MMP-9 in vulnerable plaques. Western blotting confirmed presence of the active form in plaque lysates. In vitro autoradiography showed binding of both inhibitors to stable and vulnerable plaques. Conclusions: MMPs differed in their expression patterns among plaque phenotypes, providing possible imaging targets. The two tested MMP-2/MMP-9 and MMP-9 inhibitors may be useful to detect atherosclerotic plaques, but not the vulnerable lesions selectively
PEG modification on 111In-labeled phosphatidyl serine liposomes for imaging of atherosclerotic plaques
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Introduction: Previously, we reported a probe for imaging of atherosclerotic plaques: 111In-labeled liposomes. Liposomes were modified with phosphatidylserine (PS) because macrophages recognize PS and phagocytize apoptotic cells in plaques. PS modification was successful and we could visualize atherosclerotic plaques by single-photon emission computed tomography (SPECT). However, too-rapid blood clearance reduced accumulation of PS-liposomes in plaques in vivo. Therefore, in the present study, PS-liposomes were modified with polyethylene glycol (PEG) to retard the rate of blood clearance. Methods: PS-liposomes (size, 100 nm or 200 nm) were PEGylated with PEG2000 or PEG5000 at 1 or 5 mol%, and radiolabeled with 111In. For the study of uptake in vitro, liposomes were incubated with mouse peritoneal macrophages. Biodistribution studies in vivo were carried out in ddY mice. En face autoradiograms were obtained with apoE−/− mice upon intravenous injection of 111In-liposomes. Results: Uptake was decreased significantly at 5 mol% PEGylation in 100-nm PS-liposomes (*P < 0.05 vs. 0 mol%). All the PEGylated liposomes tested showed significantly lower uptake than the non-PEGylated control in 200-nm liposomes. In vivo results showed slower blood clearance in PEGylated liposomes. Autoradiograms in apoE−/− mice were well matched with Oil Red O staining. Additionally, 200-nm PS-liposomes modified with 5%PEG2000 ([111In]5%PEG2000PS200) showed the highest uptake to the region in vivo. Conclusions: As expected, PEGylation retarded the rate of blood clearance. In addition, it affected liposome uptake by macrophages in vitro. These results suggest that the balance between the rate of blood clearance and macrophage recognition is important, and [111In]5%PEG2000PS200 showed the best results in our investigation
Nox4 NADPH oxidase contributes to smooth muscle cell phenotypes associated with unstable atherosclerotic plaques
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Shaoping Xu
Full Text Available Plaque instability associated with acute coronary syndromes results in part from apoptosis and senescence of cells within the atherosclerotic (AS lesion. Increased cellular oxidative stress has been proposed to contribute to plaque progression and changes in composition, leading to plaque instability. Our objective was to examine the role of NADPH oxidase in smooth muscle cell (SMC phenotypes associated with an unstable plaque. Aortae were isolated from pre-lesion (8 weeks of age and post-lesion (35 weeks of age hypercholesterolemic mice (ApoE−/−/LDLR−/−, AS, and age-matched normal C57BL/6J mice. We observed an age-dependent increase in reactive oxygen species (ROS in aorta from AS mice, with evidence for elevated ROS prior to lesion development. Whereas macrophage infiltration was restricted to the lesion, oxidized lipids extended beyond the plaque and into the vessel wall. Consistent with these findings, we observed dynamic changes in the expression of NADPH oxidases in AS vessels. Specifically, Nox1 expression was increased early and decreased with lesion progression, while induction of Nox4 was a late event. Nox2 and p22phox were elevated throughout lesion development. Similar to observations in aortae, SMCs isolated from the lesion of AS aortae had decreased Nox1 and increased Nox4 levels as compared to SMCs from normal mice. AS SMCs demonstrated increased generation of ROS, cell cycle arrest, evidence of senescence, and increased susceptibility to apoptosis. Overexpression of Nox4 in normal SMCs recapitulated the phenotypes of the AS SMCs. We conclude that increased expression of Nox4 in AS may drive SMC phenotypes that lead to the plaque instability and rupture responsible for myocardial infarction and stroke.
Combined micro-PIXE and NIR Raman spectroscopic plaque characterisation in a human atherosclerotic aorta sample
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Raman spectroscopy can be applied to characterise the chemical composition of an atherosclerotic plaque in vivo. In the near future this technique may become available for use in (coronary) arteries of living patients. For this moment, Raman spectroscopy is applied on artery samples in vitro, to study progression and regression of atherosclerotic plaque. Raman spectroscopy provides chemical information on a molecular basis. In this study, micro-particle induced X-ray emission (micro-PIXE) is applied to provide additional information on the elemental composition of the artery. Furthermore, the combined techniques allow for validation of the structures studied with Raman spectroscopy. This study proves that it is possible to combine and compare both techniques using the same region on the same sample if proper sample preparation is applied. Comparison shows that regions appearing in the Raman spectroscopy results can also be distinguished in micro-PIXE and backscattering spectroscopy (BS) distributions and vice versa. Combining both techniques makes it possible to separate phospholipids from triglycerides. Combined Raman spectroscopy and micro-PIXE/BS is recommended for studying progression and regression of atherosclerosis
Integrated analysis of microarray data of atherosclerotic plaques: modulation of the ubiquitin-proteasome system.
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Zhe Wang
Full Text Available Atherosclerosis is a typical complex multi-factorial disease and many molecules at different levels and pathways were involved in its development. Some studies have investigated the dysregulation in atherosclerosis at mRNA, miRNA or DNA methylation level, respectively. However, to our knowledge, the studies that integrated these data and revealed the abnormal networks of atherosclerosis have not been reported. Using microarray technology, we analyzed the omics data in atherosclerosis at mRNA, miRNA and DNA methylation levels. Our results demonstrated that the global DNA methylation and expression of miRNA/mRNA were significantly decreased in atherosclerotic plaque than in normal vascular tissue. The interaction network constructed using the integrative data revealed many genes, cellular processes and signaling pathways which were widely considered to play crucial roles in atherosclerosis and also revealed some genes, miRNAs or signaling pathways which have not been investigated in atherosclerosis until now (e.g. miR-519d and SNTB2. Moreover, the overall protein ubiquitination in atherosclerotic plaque was significantly increased. The proteasome activity was increased early but decreased in advanced atherosclerosis. Our study revealed many classic and novel genes and miRNAs involved in atherosclerosis and indicated the effects of ubiquitin-proteasome system on atherosclerosis might be closely related to the course of atherosclerosis. However, the efficacy of proteasome inhibitors in the treatment of atherosclerosis still needs more research.
Effect of Guanxinshutong capsule on the expression of matrix metalloproteinases-9 and tissue matrix metalloproteinase inhibitor-1 of atherosclerotic plaque in apoE-/- mice
Institute of Scientific and Technical Information of China (English)
Objective To approach the possible mechanism of Guanxinshutong capsule on the progression and stability of atherosclerotic plaque through observing the effects of Guanxinshutong capsule on pathologic morphology and expression of tissue matrix metalloproteinase inhibitor-1(TIMP-1),matrix metalloproteinases-9(MMP-9)of atherosclerotic plaque in Apo E-/-mice model with experimental atherosclerosis.Methods The animals were fed
Atherosclerotic plaque component segmentation in combined carotid MRI and CTA data incorporating class label uncertainty.
van Engelen, Arna; Niessen, Wiro J; Klein, Stefan; Groen, Harald C; Verhagen, Hence J M; Wentzel, Jolanda J; van der Lugt, Aad; de Bruijne, Marleen
Atherosclerotic plaque composition can indicate plaque vulnerability. We segment atherosclerotic plaque components from the carotid artery on a combination of in vivo MRI and CT-angiography (CTA) data using supervised voxelwise classification. In contrast to previous studies the ground truth for training is directly obtained from 3D registration with histology for fibrous and lipid-rich necrotic tissue, and with μCT for calcification. This registration does, however, not provide accurate voxelwise correspondence. We therefore evaluate three approaches that incorporate uncertainty in the ground truth used for training: I) soft labels are created by Gaussian blurring of the original binary histology segmentations to reduce weights at the boundaries between components, and are weighted by the estimated registration accuracy of the histology and in vivo imaging data (measured by overlap), II) samples are weighted by the local contour distance of the lumen and outer wall between histology and in vivo data, and III) 10% of each class is rejected by Gaussian outlier rejection. Classification was evaluated on the relative volumes (% of tissue type in the vessel wall) for calcified, fibrous and lipid-rich necrotic tissue, using linear discriminant (LDC) and support vector machine (SVM) classification. In addition, the combination of MRI and CTA data was compared to using only one imaging modality. Best results were obtained by LDC and outlier rejection: the volume error per vessel was 0.9±1.0% for calcification, 12.7±7.6% for fibrous and 12.1±8.1% for necrotic tissue, with Spearman rank correlation coefficients of 0.91 (calcification), 0.80 (fibrous) and 0.81 (necrotic). While segmentation using only MRI features yielded low accuracy for calcification, and segmentation using only CTA features yielded low accuracy for necrotic tissue, the combination of features from MRI and CTA gave good results for all studied components. PMID:24762678
Characterization of signal properties in atherosclerotic plaque components by intravascular MRI.
Rogers, W J; Prichard, J W; Hu, Y L; Olson, P R; Benckart, D H; Kramer, C M; Vido, D A; Reichek, N
Magnetic resonance imaging (MRI) is capable of distinguishing between atherosclerotic plaque components solely on the basis of biochemical differences. However, to date, the majority of plaque characterization has been performed by using high-field strength units or special coils, which are not clinically applicable. Thus, the purpose of the present study was to evaluate MRI properties in histologically verified plaque components in excised human carotid endarterectomy specimens with the use of a 5F catheter-based imaging coil, standard acquisition software, and a clinical scanner operating at 0.5 T. Human carotid endarterectomy specimens from 17 patients were imaged at 37 degrees C by use of an opposed solenoid intravascular radiofrequency coil integrated into a 5F double-lumen catheter interfaced to a 0.5-T General Electric interventional scanner. Cross-sectional intravascular MRI (156x250 microm in-plane resolution) that used different imaging parameters permitted the calculation of absolute T1and T2, the magnetization transfer contrast ratio, the magnitude of regional signal loss associated with an inversion recovery sequence (inversion ratio), and regional signal loss in gradient echo (gradient echo-to-spin echo ratio) in plaque components. Histological staining included hematoxylin and eosin, Masson's trichrome, Kossa, oil red O, and Gomori's iron stain. X-ray micrographs were also used to identify regions of calcium. Seven plaque components were evaluated: fibrous cap, smooth muscle cells, organizing thrombus, fresh thrombus, lipid, edema, and calcium. The magnetization transfer contrast ratio was significantly less in the fibrous cap (0.62+/-13) than in all other components (Psmooth muscle cells) were not significantly different between groups. In vitro intravascular MRI with catheter-based coils and standard software permits sufficient spatial resolution to visualize major plaque components. Pulse sequences that take advantage of differences in biochemical
Automatic plaque characterization and vessel wall segmentation in magnetic resonance images of atherosclerotic carotid arteries
Adame, Isabel M.; van der Geest, Rob J.; Wasserman, Bruce A.; Mohamed, Mona; Reiber, Johan H. C.; Lelieveldt, Boudewijn P. F.
Composition and structure of atherosclerotic plaque is a primary focus of cardiovascular research. In vivo MRI provides a meanse to non-invasively image and assess the morphological features of athersclerotic and normal human carotid arteries. To quantitatively assess the vulnerability and the type of plaque, the contours of the lumen, outer boundary of the vessel wall and plaque components, need to be traced. To achieve this goal, we have developed an automated contou detection technique, which consists of three consecutive steps: firstly, the outer boundary of the vessel wall is detected by means of an ellipse-fitting procedure in order to obtain smoothed shapes; secondly, the lumen is segnented using fuzzy clustering. Thre region to be classified is that within the outer vessel wall boundary obtained from the previous step; finally, for plaque detection we follow the same approach as for lumen segmentation: fuzzy clustering. However, plaque is more difficult to segment, as the pixel gray value can differ considerably from one region to another, even when it corresponds to the same type of tissue. That makes further processing necessary. All these three steps might be carried out combining information from different sequences (PD-, T2-, T1-weighted images, pre- and post-contrast), to improve the contour detection. The algorithm has been validated in vivo on 58 high-resolution PD and T1 weighted MR images (19 patients). The results demonstrate excellent correspondence between automatic and manual area measurements: lumen (r=0.94), outer (r=0.92), and acceptable for fibrous cap thickness (r=0.76).
Magnetization transfer magnetic resonance of human atherosclerotic plaques ex vivo detects areas of high protein density
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Qiao Ye
Full Text Available Abstract Background Proteins are major plaque components, and their degradation is related to the plaque instability. We sought to assess the feasibility of magnetization transfer (MT magnetic resonance (MR for identifying fibrin and collagen in carotid atherosclerotic plaques ex vivo. Methods Human carotid artery specimens (n = 34 were obtained after resection from patients undergoing endarterectomy. MR was completed within 12 hr after surgery on an 11.7T MR microscope prior to fixation. Two sets of T1W spoiled gradient echo images were acquired with and without the application of a saturation pulse set to 10 kHz off resonance. The magnetization transfer ratio (MTR was calculated, and the degree of MT contrast was correlated with histology. Results MT with appropriate calibration clearly detected regions with high protein density, which showed a higher MTR (thick fibers (collagen type I (54 ± 8% compared to regions with a low amount of protein including lipid (46 ± 8% (p = 0.05, thin fibers (collagen type III (11 ± 6% (p = 0.03, and calcification (6.8 ± 4% (p = 0.02. Intraplaque hemorrhage (IPH with different protein density demonstrated different MT effects. Old (rich in protein debris and recent IPH (rich in fibrin had a much higher MTR 69 ± 6% and 55 ± 9%, respectively, compared to fresh IPH (rich in intact red blood cells(9 ± 3%. Conclusions MT MR enhances plaque tissue contrast and identifies the protein-rich regions of carotid artery specimens. The additional information from MTR of IPH may provide important insight into the role of IPH on plaque stability, evolution, and the risk for future ischemic events.
Assessment of atherosclerotic plaque vulnerability of coronary arteries in cases of sudden cardiac death
International Nuclear Information System (INIS)
To study the plaque vulnerability in coronary arteries taken from autopsy specimens, of individuals dying of ischemic heart disease in our setup and to compare it with atheroma of those who died of non-cardiac causes. Sixty coronary arteries having atherosclerosis, from autopsies of patients who died of sudden cardiac death were divided into case and control groups. Case group included thirty coronary arteries having atherosclerosis from autopsies of patients of whose death was attributable to Ischemic Heart Disease (IHD). Control group included thirty coronary arteries where atherosclerotic changes were found by chance (death not attributable to ischemic heart disease). Plaques were assessed for fibrous cap thickness, foam cells; mean percentage of inflammatory cells on Haemotoxylin and Eosin (H and E) stained slides whereas immunohistochemical (IHC) markers for T-Cells were done by IHC stain method. In present study, foam cells are significantly more in study group than in control group (P=0.007). Fibrous cap thickness fulfilling the criteria of vulnerable plaque was more in study group as compared to control group (P<0.001). The present study demonstrated that there was insignificant difference (P=0.152), in the mean percentage of inflammatory cells in case group and control group. An overall significant association was found between vulnerable plaque and death due to ischemic heart disease (P<0.001). Conclusion: Patients dying of ischemic heart disease have more vulnerable plaque in their coronary arteries as compared to those dying from non ischemic cause. Although this is an autopsy study but the significance of in this study can be very important to guide cardiologists to identify patients at high risk of acute coronary syndrome and use new diagnostic modalities like intravascular ultrasonography and therapeutic strategies like genomic and proteomic techniques. This will help the early detection and treatment of such cases and may ultimately reduce the
A Framework for Local Mechanical Characterization of Atherosclerotic Plaques: Combination of Ultrasound Displacement Imaging and Inverse Finite Element Analysis.
Akyildiz, Ali C; Hansen, Hendrik H G; Nieuwstadt, Harm A; Speelman, Lambert; De Korte, Chris L; van der Steen, Antonius F W; Gijsen, Frank J H
Biomechanical models have the potential to predict plaque rupture. For reliable models, correct material properties of plaque components are a prerequisite. This study presents a new technique, where high resolution ultrasound displacement imaging and inverse finite element (FE) modeling is combined, to estimate material properties of plaque components. Iliac arteries with plaques were excised from 6 atherosclerotic pigs and subjected to an inflation test with pressures ranging from 10 to 120 mmHg. The arteries were imaged with high frequency 40 MHz ultrasound. Deformation maps of the plaques were reconstructed by cross correlation of the ultrasound radiofrequency data. Subsequently, the arteries were perfusion fixed for histology and structural components were identified. The histological data were registered to the ultrasound data to construct FE model of the plaques. Material properties of the arterial wall and the intima of the atherosclerotic plaques were estimated using a grid search method. The computed displacement fields showed good agreement with the measured displacement fields, implying that the FE models were able to capture local inhomogeneities within the plaque. On average, nonlinear stiffening of both the wall and the intima was observed, and the wall of the atheroslcerotic porcine iliac arteries was markedly stiffer than the intima (877 ± 459 vs. 100 ± 68 kPa at 100 mmHg). The large spread in the data further illustrates the wide variation of the material properties. We demonstrated the feasibility of a mixed experimental-numerical framework to determine the material properties of arterial wall and intima of atherosclerotic plaques from intact arteries, and concluded that, due to the observed variation, plaque specific properties are required for accurate stress simulations. PMID:26399991
Comparison of MRI and DSA in assessment of carotid artery stenosis and atherosclerotic plaque
International Nuclear Information System (INIS)
Objective: To compare the efficacy of MRI and DSA in assessment of carotid artery stenosis and atherosclerotic plaque. Methods: Forty-six patients with carotid plaque detected by ultrasound were enrolled in this study, and 89 carotid arteries were evaluated by MRI and DSA. MRI examination was acquired with 3.0 T MR scanner and 8 channel phase-array surface coil. The MRI sequences consisted of pre-and post-contrast T1WI, T2WI, PDWI, TOF. Anterior-posterior and lateral views of carotid artery were performed on DSA. The degree of carotid artery stenosis was evaluated by the NASCET standard. Fibrous cap rupture, intraplaque hemorrhage, and calcification were also evaluated on MRI and DSA. Statistical comparison was performed with the Kappa value and paired Chi-square test. Results: The degree of carotid artery stenosis was 50% (16%-78%) on MRI and 47% (7%-73%) on DSA. Two imaging modalities were in good consistency in evaluation of the degree of stenosis (Kappa = 0.882, P2 =20.346, P<0.01). Furthermore, thirty-seven vessels with intraplaque hemorrhage and 71 vessels with calcification in the plaque were found on MRI but none on DSA. Conclusion: MRI is a reliable tool in assessment of the degree of the carotid stenosis and it is superior to DSA in detecting fibrous cap rupture, intraplaque hemorrhage, and calcification. (authors)
High-normal blood pressure and carotid atherosclerotic plaque formation: The results from stroke population screening in Dongying, Shandong province%正常高值血压与颈动脉粥样硬化斑块形成:来自山东东营卒中筛查人群的结果
Institute of Scientific and Technical Information of China (English)
吴德云; 刘迎春; 高宗恩; 李楠; 杨志杰
目的 探讨不同血压水平与颈动脉粥样斑块形成的相关性.方法 从2012年9月至2013年1月期间参加东营市卒中筛查的人群中,选取符合理想血压[收缩压(systolic blood pressure,SBP)< 120 mm Hg且舒张压(diastolic blood pressure,DBP)< 80 mm Hg,1 mm Hg =0.133 kPa]、正常血压[SBP 120~129 mm Hg和(或)DBP 80 ~84 mm Hg]和正常高值血压[SBP 130~139 mm Hg和(或)DBP 85~89 mm Hg]诊断标准的人群为研究对象,进行间卷调查、体格检查、血生化检查及颈部血管超声检查.比较正常血压组、正常高值血压组与理想血压组之间颈动脉斑块检出率,进行多变量logistic回归分析确定颈动脉斑块的独立危险因素.结果 正常血压组和正常高值血压组男性和糖尿病的构成比以及体质指数(body mass index,BMI)和空腹血糖(fasting blood glucose,FBG)水平均显著性高于理想血压组(P均<0.05).理想血压组、正常血压组和正常高值血压组颈动脉斑块检出率分别为12.41%、38.14%和49.45%.颈动脉斑块形成组男性构成比以及年龄、SBP、FBG和高半胱氨酸(homocysteine,Hcy)水平均显著性高于无颈动脉斑块形成组(P均<0.05).多变量logistic回归分析显示,年龄、SBP、FBG和Hcy为颈动脉粥样斑块形成的独立危险因素,女性为独立保护因素.在校正性别、年龄、FBG和Hcy等危险因素后,正常高值血压组斑块形成风险显著性高于理想血压组(优势比1.354,95%可信区间1.028~1.783;P=0.031),而正常血压组与理想血压组无显著性差异.结论 正常高值血压与颈动脉斑块形成风险增高显著相关,是颈动脉斑块形成的独立危险因素.%Objective To investigate the correlation between different blood pressure levels and carotid atherosclerotic plaque formation.Methods The population participated in stroke screening were selected from September 2012 to January 2013 in Dongying,Shandong province.The subjects met the
Overexpression of TGF-ß1 in macrophages reduces and stabilizes atherosclerotic plaques in ApoE-deficient mice.
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Kurt Reifenberg
Full Text Available Although macrophages represent the hallmark of both human and murine atherosclerotic lesions and have been shown to express TGF-ß1 (transforming growth factor β1 and its receptors, it has so far not been experimentally addressed whether the pleiotropic cytokine TGF-ß1 may influence atherogenesis by a macrophage specific mechanism. We developed transgenic mice with macrophage specific TGF-ß1 overexpression, crossed the transgenics to the atherosclerotic ApoE (apolipoprotein E knock-out strain and quantitatively analyzed both atherosclerotic lesion development and composition of the resulting double mutants. Compared with control ApoE(-/- mice, animals with macrophage specific TGF-ß1 overexpression developed significantly less atherosclerosis after 24 weeks on the WTD (Western type diet as indicated by aortic plaque area en face (p<0.05. Reduced atherosclerotic lesion development was associated with significantly less macrophages (p<0.05 after both 8 and 24 weeks on the WTD, significantly more smooth muscle cells (SMCs; p<0.01 after 24 weeks on the WTD, significantly more collagen (p<0.01 and p<0.05 after 16 and 24 weeks on the WTD, respectively without significant differences of inner aortic arch intima thickness or the number of total macrophages in the mice pointing to a plaque stabilizing effect of macrophage-specific TGF-ß1 overexpression. Our data shows that macrophage specific TGF-ß1 overexpression reduces and stabilizes atherosclerotic plaques in ApoE-deficient mice.
Detection of HOCl-mediated protein oxidation products in the extracellular matrix of human atherosclerotic plaques
DEFF Research Database (Denmark)
Woods, Alan A; Linton, Stuart M; Davies, Michael Jonathan
83-96% of the total oxidized protein side-chain products detected in these plaques. Oxidation of matrix components extracted from healthy artery tissue, and model proteins, with reagent HOCl is shown to give rise to a similar pattern of products to those detected in advanced human lesions. The......Oxidation is believed to play a role in atherosclerosis. Oxidized lipids, sterols and proteins have been detected in early, intermediate and advanced human lesions at elevated levels. The spectrum of oxidized side-chain products detected on proteins from homogenates of advanced human lesions has...... material obtained from advanced human atherosclerotic lesions are shown to contain elevated levels of oxidized amino acids [3,4-dihydroxyphenylalanine (DOPA), di-tyrosine, 2-hydroxyphenylalanine ( o-Tyr)] when compared with healthy (human and pig) arterial tissue. These matrix-derived materials account for...
Neovascularization and coronary atherosclerotic plaque: cinematographic localization and quantitative histologic analysis.
Kamat, B R; Galli, S J; Barger, A C; Lainey, L L; Silverman, K J
A new technique was developed for analyzing the neovascularization associated with coronary artery atherosclerosis: cinematography during silicone polymer injection of the coronary arteries of fixed and cleared human hearts, followed by histologic analysis in routine and 1-micron-thick, Epon-embedded sections. Twenty-two hearts obtained at autopsy were studied. On the basis of cinematographic findings, individual regions of the coronary arteries were classified as negative, positive, or abundantly positive for neovascularization. Positive and abundantly positive areas, which invariably occurred in segments exhibiting changes of atherosclerosis, contained numerous small vessels in the adventitia and outer media (4.7 +/- 1.5 and 9.8 +/- 1.3 [SE] vessel profiles/artery cross-section in positive and abundantly positive areas, versus 1.0 +/- 0.6 in negative regions). Abundantly positive areas, which occurred in coronary artery segments demonstrating the most extensive atherosclerotic change, contained numerous small vessels in the inner media or in the plaque itself. Some of these microvessels were in close proximity to mast cells, which represent potentially rich sources of mediators affecting vascular tone and permeability. Vessels were not observed in the inner media or in atherosclerotic plaque in areas designated either positive or negative by cinematography. These findings show how our approach can be used both to define the three-dimensional, in situ configuration of coronary artery neovascularization and to characterize the histology of this process in detail. They also confirm previous work indicating that areas of coronary arteries involved by atherosclerosis frequently exhibit extensive neovascularization. PMID:2443438
Intravascular optical coherence tomography: differentiation of atherosclerotic plaques and quantification of vessel dimensions in crural arterial specimens
International Nuclear Information System (INIS)
Purpose: Intravascular optical coherence tomography (OCT) is a new technique based on infrared light that visualizes the arteries with a resolution of 10-20 μm. Intravascular ultrasound (IVUS) is the current in vivo reference standard and provides a resolution of 100-150 μm. This study compared OCT to IVUS and histopathology with respect to the ability to differentiate atherosclerotic plaques and quantify vascular dimensions in peripheral crural arteries ex vivo. Materials and Methods: 50 segments of atherosclerotic arteries derived from five amputated human lower extremities were examined. The different plaque types (fibrous, high-lipid content, calcified) were assigned by two independent examiners, and the sensitivity and specificity of OCT in comparison with histopathology as well as intra- and interobserver consensus were calculated. A comparison of OCT with IVUS addressed the parameters: luminal area (LA), vascular wall area (VA) and plaque area (PA). Results: When comparing OCT and histopathology with respect to the differentiation of various plaque types, sensitivities of 81% and specificities of 89% for fibrous plaques, of 100% and 93% for lipid-rich plaques and of 80% and 89% for calcified plaques were achieved (overall correlation 83%). Intra- and interobserver consensus was very high (κ=0.86 and κ=0.89, p2 accuracy ±1.8 mm2, r=0.95[p2 accuracy ±2.3 mm2, r=0.94[p2 accuracy ±2.3 mm2, r=0.80[p<0.01]). Conclusion: OCT allows the differentiation of atherosclerotic plaque types in crural arteries with high accuracy compared to histopathology. Quantitative measurements show a high correlation with IVUS, the current reference standard. (orig.)
Effect of sexual steroids on the calcium content of aortic atherosclerotic plaque of oophorectomized rabbits
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J.M. Aldrighi
Full Text Available We determined the effect of conjugated equine estrogen plus medroxyprogesterone acetate on calcium content of aortic atherosclerotic lesions in oophorectomized adult New Zealand rabbits submitted to a cholesterol rich diet. Five groups of 10 animals each were studied: G1 = control, G2 = cholesterol diet only, G3 = diet plus conjugated equine estrogen (0.625 mg/day; G4 and G5 = diet, conjugated equine estrogen (0.625 mg/day plus medroxyprogesterone acetate (5 and 10 mg/day, respectively. Mean weight varied from 2.7 ± 0.27 to 3.1 ± 0.20 kg (P = 0.38 between groups at the beginning and 3.1 ± 0.27 to 3.5 ± 0.20 kg (P = 0.35 at the end of the experiment. Cholesterol and triglyceride levels were determined at the time of oophorectomy, 21 days after surgery (time 0, and at the end of follow-up of 90 days. The planimetric method was used to measure plaque and caryometric method for histopathologic examination of the aorta. Calcium content was determined by the method of von Kossa. A similar increase in cholesterol occurred in all treated groups without differences between them at the end of the study. Groups G4 and G5 had smaller areas of atherosclerotic lesions (2.33 ± 2.8 and 2.45 ± 2.1 cm², respectively than the groups receiving no progestogens (G2: 5.6 ± 4 and G3: 4.6 ± 2.8 cm²; P = 0.02. The relation between lesion area and total aorta area was smaller in groups treated with combined drugs compared to the groups receiving no progesterone (G4: 14.9 ± 13 and G5: 14.2 ± 13.4 vs G2: 35.8 ± 26 and G3: 25 ± 8 cm², respectively; P = 0.017. Oral conjugated equine estrogen (0.625 mg/day plus medroxyprogesterone acetate (5 or 10 mg/day provoked a greater reduction in atherosclerotic plaque area and calcium content in treated groups, suggesting a dose-dependent effect.
Identification of atherosclerotic plaque components using cluster analysis of multispectral MR images: comparison with histology
Clarke, Sharon; Rutt, Brian K.; Lucas, Alexandra; Lownie, Stephen P.; Hammond, Robert; Mitchell, Ross
The composition of atherosclerotic lesions in the carotid arteries is believed to be an important predictor of stroke risk. Several MR contrasts may be necessary to discriminate between different plaque components, and multispectral analysis can used to integrate the information obtained from these multiple contrasts. This study presents the use of registered MR and histological images of carotid endarterectomy specimens as a tool for the quantitative assessment of maximum likelihood classification and other segmentation algorithms. Carotid endarterectomy specimens were imaged in a 1.5T GE Signa scanner. PD, T1, T2, diffusion spin echo weightings were obtained. MR images were registered with digitized images of the corresponding histology. A pathologist identified regions of collagen, calcification, cholesterol, hemorrhage on the histological images. Training and ground truth regions were selected. The accuracy of the maximum likelihood classification was assessed on a pixel by pixel basis using truth regions identified on histological images. The accuracy of multispectral analysis was calcification (73%), fibrin (68%), cholesterol (62%), fibrous plaque (53%). This technique was limited by registration inaccuracies caused by partial volume effects and histological artifacts. Despite these limitations, accuracy results were reasonable. This technique, with continued improvements, provides a framework for evaluating the accuracy of different segmentation algorithms.
Histopathologic Characteristics of Atherosclerotic Coronary Disease and Implications of the Findings for the Invasive and Noninvasive Detection of Vulnerable Plaques
Narula, Jagat; Nakano, Masataka; Virmani, Renu; Kolodgie, Frank D.; Petersen, Rita; Newcomb, Robert; Malik, Shaista; Fuster, Valentin; Finn, Aloke V.
Objectives The goal of this study was to identify histomorphologic characteristics of atherosclerotic plaques and to determine the amenability of some of these components to be used as markers for invasive and noninvasive imaging. Background Rupture of the atherosclerotic plaques is responsible for the majority of acute coronary events, and the culprit lesions demonstrate distinct histopathologic features. It has been tacitly believed that plaque rupture (PR) is associated with angiographically minimally occlusive lesions. Methods We obtained 295 coronary atherosclerotic plaques, including stable (fibroatheroma [FA]; n = 105), vulnerable (thin-cap fibroatheroma [TCFA]; n = 88), and disrupted plaques (plaque rupture [PR]; n = 102) from the hearts of 181 men and 32 women who had died suddenly. The hierarchical importance of fibrous cap thickness, percent luminal stenosis, macrophage area, necrotic core area, and calcified plaque area was evaluated by using recursive partitioning analysis. Because clinical assessment of fibrous cap thickness is not possible by noninvasive imaging, it was excluded from the second set of partitioning analysis. Results Thickness of the fibrous cap emerged as the best discriminator of plaque type; the cap thickness measured 84-μm cap thickness. Although the majority of TCFA were found in the 54- to 84-μm thickness group, those with <54-μm thickness were more likely to show <74% luminal stenosis (area under the curve: FA, 1.0; TCFA, 0.89; PR, 0.90). After exclusion of cap thickness, analysis of the plaque characteristics revealed macrophage infiltration and necrotic core to be the 2 best discriminators of plaque types (area under the curve: FA, 0.82; TCFA, 0.58; PR, 0.72). More than 75% cross-section area stenosis was seen in 70% of PR and 40% of TCFA; only 5% PR and 10% TCFA were <50% narrowed. Conclusions This postmortem study defines histomorphologic characteristics of vulnerable plaques, which may help develop imaging strategies for
Cross-reacting antibacterial auto-antibodies are produced within coronary atherosclerotic plaques of acute coronary syndrome patients.
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Filippo Canducci
Full Text Available Coronary atherosclerosis, the main condition predisposing to acute myocardial infarction, has an inflammatory component caused by stimuli that are yet unknown. We molecularly investigated the nature of the immune response within human coronary lesion in four coronary plaques obtained by endoluminal atherectomy from four patients. We constructed phage-display libraries containing the IgG1/kappa antibody fragments produced by B-lymphocytes present in each plaque. By immunoaffinity, we selected from these libraries a monoclonal antibody, arbitrarily named Fab7816, able to react both with coronary and carotid atherosclerotic tissue samples. We also demonstrated by confocal microscopy that this monoclonal antibody recognized human transgelin type 1, a cytoskeleton protein involved in atherogenesis, and that it co-localized with fibrocyte-like cells transgelin+, CD68+, CD45+ in human sections of coronary and carotid plaques. In vitro fibrocytes obtained by differentiating CD14+ cells isolated from peripheral blood mononuclear cells also interacted with Fab7816, thus supporting the hypothesis of a specific recognition of fibrocytes into the atherosclerotic lesions. Interestingly, the same antibody, cross-reacted with the outer membrane proteins of Proteus mirabilis and Klebsiella pneumoniae (and possibly with homologous proteins of other enterobacteriaceae present in the microbiota. From all the other three libraries, we were able to clone, by immunoaffinity selection, human monoclonal antibodies cross-reacting with bacterial outer membrane proteins and with transgelin. These findings demonstrated that in human atherosclerotic plaques a local cross-reactive immune response takes place.
Identifying Vulnerable Atherosclerotic Plaque in Rabbits Using DMSA-USPIO Enhanced Magnetic Resonance Imaging to Investigate the Effect of Atorvastatin.
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Chunmei Qi
Full Text Available Rupture of an atherosclerotic plaque is the primary cause of acute cardiovascular and cerebrovascular syndromes. Early and non-invasive detection of vulnerable atherosclerotic plaques (VP would be significant in preventing some aspects of these syndromes. As a new contrast agent, dimercaptosuccinic acid (DMSA modified ultra-small super paramagnetic iron oxide (USPIO was synthesized and used to identify VP and rupture plaque by magnetic resonance imaging (MRI.Atherosclerosis was induced in male New Zealand White rabbits by feeding a high cholesterol diet (n = 30. Group A with atherosclerosis plaque (n = 10 were controls. VP was established in groups B (n = 10 and C (n = 10 using balloon-induced endothelial injury of the abdominal aorta. Adenovirus-carrying p53 genes were injected into the aortic segments rich in plaques after 8 weeks. Group C was treated with atorvastatin for 8 weeks. Sixteen weeks later, all rabbits underwent pharmacological triggering, and imaging were taken daily for 5 d after DMSA-USPIO infusion. At the first day and before being killed, serum MMP-9, sCD40L, and other lipid indicators were measured.DMSA-USPIO particles accumulated in VP and rupture plaques. Rupture plaques appeared as areas of hyper-intensity on DMSA-USPIO enhanced MRI, especially T2*-weighted sequences, with a signal strength peaking at 96 h. The group given atorvastatin showed few DMSA-USPIO particles and had lower levels of serum indicators. MMP-9 and sCD40L levels in group B were significantly higher than in the other 2 groups (P <0.05.After successfully establishing a VP model in rabbits, DMSA-USPIO was used to enhance MRI for clear identification of plaque inflammation and rupture. Rupture plaques were detectable in this way probably due to an activating inflammatory process. Atorvastatin reduced the inflammatory response and stabilizing VP possibly by decreasing MMP-9 and sCD40L levels.
Relationship between changes in coronary atherosclerotic plaque burden measured by intravascular ultrasound and cardiovascular disease outcomes: a systematic literature review.
Forbes, Carol; Quek, Ruben G W; Deshpande, Sohan; Worthy, Gill; Ross, Janine; Kleijnen, Jos; Gandra, Shravanthi R; Kassahun, Helina; Wong, Nathan D; Nicholls, Stephen J
Objective Evidence from coronary imaging studies suggests an association between increased atherosclerotic plaque burden and cardiovascular disease (CVD) outcomes. A systematic review was performed to evaluate the relationship between coronary atherosclerotic plaque burden changes measured by intravascular ultrasound (IVUS) and CVD outcomes. Research design and methods Rigorous systematic review methodology was used to identify prospective studies of any design assessing the relationship between atherosclerotic plaque volume (percentage or total atheroma volume [PAV or TAV]) changes and CVD outcomes, using multivariable analyses. Main outcome measures CVD outcomes including major adverse cardiac events (MACEs) and major adverse cardiac and cerebrovascular events (MACCEs). Results Literature searches from inception to February 2015 retrieved 6958 records after de-duplication. From these four studies (14 papers) were included. One study reported a significantly lower rate of CVD outcomes associated with a greater reduction in PAV (hazard ratio [HR] 0.26, 95% confidence interval [CI] 0.07-0.83). One study reported that large plaque volume was significantly associated with a greater risk of major adverse cardiac events (MACEs) (HR 1.73, 95% CI: 1.02-2.96). Similarly, a third study reported a significant increase in MACE with an increase in baseline PAV (HR 1.51, 95% CI: 1.06-2.51). Only one potentially inadequately powered Japanese study did not find a statistically significant relationship between PAV changes and MACE. Conclusions The current evidence suggests an independent and statistically significant association between increases in coronary atherosclerotic plaque burden measured by IVUS and greater long-term risk of future CVD outcomes. However, this evidence comes from a limited number of studies which mainly focus on Japanese populations and populations after PCI. Further large prospective studies are required to confirm these findings. PMID:26949994
Control study of MRI and histopathology in early atherosclerotic plaque of rabbits
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Objective: To explore the diagnostic value of MRI in the early atherosclerosis. Materials and Methods: Atherosclerosis was induced in 20 New Zealand White male rabbits with high cholesterol diet. Rabbits underwent serial MRI at 9 and 18 weeks after high cholesterol diet. Axial T1 and fat-suppressed PDWI spin echo images of the abdominal aorta were obtained above and below the right renal arteries. The signal intensity and morphologic features of plaque in the various phases after high cholesterol diet in MRI were analyzed and compared with those of histopathology. Results: Plaque could be observed in all animals on MRI at 9 weeks after high cholesterol diet, and mild enhancement of the plaque could be noted on enhanced imaging. Imaging effect was the best at T1 sequence. Plaque size increased gradually at 18 weeks. Plaque and vessel wall were all enrichment. In histopathology, foam cells, collagen and matrix fiber component can be seen in the various phases. Conclusion: The conventional MRI technique can be used to assess the formation and development of the early atherosclerosis dynamically and histologically. (authors)
Psychological stress increases expression of aortic plaque intercellular adhesion molecule-1 and serum inflammatory cytokines in atherosclerotic rabbit model
Institute of Scientific and Technical Information of China (English)
Muwei Li; Xianpei Wang; Lei Yang; Chuanyu Gao; Yexin Ma
Plaque rupture,platelet aggregation,and thrombogenesis are the main mechanisms of acute coronary syndrome (ACS),and inflammation factors play key roles in plaque unstability.Psychological stress promotes acute inflammatory response,leading to increased circulating levels of C-reactive protein (CRP),IL-6,and serum intercellular adhesion molecule (sICAM)-1.But it is not clear that whether psychological stress has a direct effect on atherosclerotic plaque stability.The purpose of this study was to investigate effects of chronic psychological stress on inflammatory marker (ICAM-1 ) in atherosclerotic plaque,and inflammatory markers in peripheral blood.Materials and methods Sixty male rabbits were randomized into 2 groups:the control group (n =10) and the atherosclerotic group (n =50).The latter were fed on high fatty diet and were given a large dose of vitamin D3 (3 600 000IU/kg) via intraperitoneal injection.After 8 weeks,the atherosclerotic model was estaslished.Then the 50 atherosclerotic model rabbits were divided into 3 subgroups:no-stress subgroup (n = 16),physiological stress subgroup (n = 16) and psychological stress subgroup (n =18).In physiological stress subgroup and psychological stress subgroup,drinking was cut from twice a day to once a day.At the same time,psychological stress subgroup was given empty bottle stress,and this process lasted for 2 weeks.One hour after the last stress,the blood samples were collected and the serum levels of CRP,IL-6 amd ICAM-1 were tested by radioimmunoassay or enzyme linked immunosorbent assay.The aorta and heart were extracted for pathology examination,and the express of ICAM-1 was tested by immunohistochemical examination.Results (1) After effective atherosclerotic animal model construction,the expression of ICAM-1 in aorta was higher in atherosclerotic group than that in control group (P<0.01),and was notably higher in psychological stress subgroup than that in no-stress subgroup or in physiological stress subgroup (2
Adhesive strength of atherosclerotic plaque in a mouse model depends on local collagen content and elastin fragmentation.
Wang, Ying; Johnson, John A; Fulp, Abigail; Sutton, Michael A; Lessner, Susan M
Atherosclerotic plaque rupture is a major cause of myocardial infarction and ischemic stroke. The adhesive strength of the bond between a plaque and the vascular wall, measured as local energy release rate, G, is used for quantitative plaque stability estimation. We tested the hypothesis that adhesive strength varies with plaque composition. Matrix metalloproteinase-12 (MMP12) deficiency was previously reported to alter lesion composition. To estimate G values, peeling experiments are performed on aortic plaques from apolipoprotein E knockout (apoE KO) and apoE MMP12 double knockout (DKO) male mice after 8 months on high-fat diet. For plaques in apoE KO and apoE MMP12 DKO mice, experimental values for G differ significantly (paveraging 19.2J/m(2) and 12.1J/m(2), respectively. Histology confirms that plaques delaminate along their interface with the underlying internal elastic lamina (IEL) in both genotypes. Quantitative image analysis of stained tissue sections demonstrates a significant positive correlation (p<0.05) between local collagen content of lesions and G values in both genotypes, indicating that adhesive strength of plaques depends on local collagen content. Surprisingly, macrophage content of aortic plaques is neither significantly correlated with G values nor significantly different between genotypes. The IEL underlying plaques in apoE KO mice is significantly more fragmented (number of breaks and length of breaks) than in apoE MMP12 DKO mice, suggesting that elastin fragmentation also influences adhesion strength of plaques. Overall, our results suggest that plaques adhere more strongly to the underlying IEL in apoE KO mice than in apoE MMP12 DKO mice. PMID:23261250
Atherosclerotic plaque volume and composition in symptomatic carotid arteries assessed with multidetector CT angiography; relationship with severity of stenosis and cardiovascular risk factors
Rozie, S.; de Weert, T. T.; de Monyé, C.; Homburg, P. J.; Tanghe, H L J; Dippel, D W J; van der Lugt, A.
The purpose of this study was to examine the volume and the composition of atherosclerotic plaque in symptomatic carotid arteries and to investigate the relationship between these plaque features and the severity of stenosis and the presence of cardiovascular risk factors. One hundred patients with cerebrovascular symptoms underwent CT angiography. We measured plaque volume (PV) and the relative contribution of plaque components (calcifications, fibrous tissue, and lipid) in the symptomatic a...
Tiaozhi Tongmai Granules reduce atherogenesis and promote the expression of ATP-binding cassette transporter A1 in rabbit atherosclerotic plaque macrophages and the liver
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Qing Sun
Conclusions: Tiaozhi Tongmai Granules appear to have an anti-atherogenic effect that is most likely mediated by simultaneously upregulating the protein expression of ABCA1 in rabbit atherosclerotic plaque macrophages and in the liver.
Cadmium exposure and atherosclerotic carotid plaques –Results from the Malmö diet and Cancer study
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Fagerberg, Björn, E-mail: email@example.com [Department of Molecular and Clinical Medicine, Wallenberg Laboratory for Cardiovascular and Metabolic Research, University of Gothenburg, Sahlgrenska University Hospital, SE-413 45 Gothenburg (Sweden); Barregard, Lars, E-mail: firstname.lastname@example.com [Occupational and Environmental Medicine, Sahlgrenska University Hospital and University of Gothenburg, SE 413 45 Gothenburg (Sweden); Sallsten, Gerd, E-mail: firstname.lastname@example.com [Occupational and Environmental Medicine, Sahlgrenska University Hospital and University of Gothenburg, SE 413 45 Gothenburg (Sweden); Forsgard, Niklas, E-mail: email@example.com [Department of Clinical Chemistry, Sahlgrenska University Hospital, SE-413 45 Gothenburg (Sweden); Östling, Gerd, E-mail: email@example.com [Cardiovascular Epidemiology, Department of Clinical Sciences in Malmö, CRC, Jan Waldenströms gata 35, Skane University Hospital, Malmö, 205 02 Malmö (Sweden); Persson, Margaretha, E-mail: firstname.lastname@example.com [Cardiovascular Epidemiology, Department of Clinical Sciences in Malmö, CRC, Jan Waldenströms gata 35, Skane University Hospital, Malmö, 205 02 Malmö (Sweden); Borné, Yan, E-mail: email@example.com [Cardiovascular Epidemiology, Department of Clinical Sciences in Malmö, CRC, Jan Waldenströms gata 35, Skane University Hospital, Malmö, 205 02 Malmö (Sweden); and others
Background: Epidemiological studies indicate that cadmium exposure through diet and smoking is associated with increased risk of cardiovascular disease. There are few data on the relationship between cadmium and plaques, the hallmark of underlying atherosclerotic disease. Objectives: To examine the association between exposure to cadmium and the prevalence and size of atherosclerotic plaques in the carotid artery. Methods: A population sample of 4639 Swedish middle-aged women and men was examined in 1991–1994. Carotid plaque was determined by B-mode ultrasound. Cadmium in blood was analyzed by inductively coupled plasma mass spectrometry. Results: Comparing quartile 4 with quartile 1 of blood cadmium, the odds ratio (OR) for prevalence of any plaque was 1.9 (95% confidence interval 1.6–2.2) after adjustment for sex and, age; 1.4 (1.1–1.8) after additional adjustment for smoking status; 1.4 (1.1–1.7) after the addition of education level and life style factors; 1.3 (1.03–1.8) after additional adjustment for risk factors and predictors of cardiovascular disease. No effect modification by sex was found in the cadmium-related prevalence of plaques. Similarly, ORs for the prevalence of small and large plaques were after full adjustment 1.4 (1.0–2.1) and 1.4 (0.9–2.0), respectively. The subgroup of never smokers showed no association between cadmium and atherosclerotic plaques. Conclusions: These results extend previous studies on cadmium exposure and clinical cardiovascular events by adding data on the association between cadmium and underlying atherosclerosis in humans. The role of smoking remains unclear. It may both cause residual confounding and be a source of pro-atherogenic cadmium exposure. - Highlights: • Blood cadmium level is associated with atherosclerotic plaques in the carotid artery. • The results extend previous knowledge of cadmium exposure and clinical events. • The role of smoking remains unclear.
Cadmium exposure and atherosclerotic carotid plaques –Results from the Malmö diet and Cancer study
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Background: Epidemiological studies indicate that cadmium exposure through diet and smoking is associated with increased risk of cardiovascular disease. There are few data on the relationship between cadmium and plaques, the hallmark of underlying atherosclerotic disease. Objectives: To examine the association between exposure to cadmium and the prevalence and size of atherosclerotic plaques in the carotid artery. Methods: A population sample of 4639 Swedish middle-aged women and men was examined in 1991–1994. Carotid plaque was determined by B-mode ultrasound. Cadmium in blood was analyzed by inductively coupled plasma mass spectrometry. Results: Comparing quartile 4 with quartile 1 of blood cadmium, the odds ratio (OR) for prevalence of any plaque was 1.9 (95% confidence interval 1.6–2.2) after adjustment for sex and, age; 1.4 (1.1–1.8) after additional adjustment for smoking status; 1.4 (1.1–1.7) after the addition of education level and life style factors; 1.3 (1.03–1.8) after additional adjustment for risk factors and predictors of cardiovascular disease. No effect modification by sex was found in the cadmium-related prevalence of plaques. Similarly, ORs for the prevalence of small and large plaques were after full adjustment 1.4 (1.0–2.1) and 1.4 (0.9–2.0), respectively. The subgroup of never smokers showed no association between cadmium and atherosclerotic plaques. Conclusions: These results extend previous studies on cadmium exposure and clinical cardiovascular events by adding data on the association between cadmium and underlying atherosclerosis in humans. The role of smoking remains unclear. It may both cause residual confounding and be a source of pro-atherogenic cadmium exposure. - Highlights: • Blood cadmium level is associated with atherosclerotic plaques in the carotid artery. • The results extend previous knowledge of cadmium exposure and clinical events. • The role of smoking remains unclear
Non-invasive imaging of atherosclerotic plaque macrophage in a rabbit model with F-18 FDG PET: a histopathological correlation
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Coronary atherosclerosis and its thrombotic complications are the major cause of mortality and morbidity throughout the industrialized world. Thrombosis on disrupted atherosclerotic plaques plays a key role in the onset of acute coronary syndromes. Macrophages density is one of the most critical compositions of plaque in both plaque vulnerability and thrombogenicity upon rupture. It has been shown that macrophages have a high uptake of 18F-FDG (FDG). We studied the correlation of FDG uptake with histopathological macrophage accumulation in atherosclerotic plaques in a rabbit model. Atherosclerosis was induced in rabbits (n = 6) by a combination of atherogenic diet and balloon denudation of the aorta. PET imaging was performed at baseline and 2 months after atherogenic diet and coregistered with magnetic resonance (MR) imaging. Normal (n = 3) rabbits served as controls. FDG uptake by the thoracic aorta was expressed as concentration (μCi/ml) and the ratio of aortic uptake-to-blood radioactivity. FDG uptake and RAM-11 antibody positive areas were analyzed in descending aorta. Atherosclerotic aortas showed significantly higher uptake of FDG than normal aortas. The correlation of aortic FDG uptake with macrophage areas assessed by histopathology was statistically significant although it was not high (r = 0.48, p < 0.0001). When uptake was expressed as the ratio of aortic uptake-to-blood activity, it correlated better (r = 0.80, p < 0.0001) with the macrophage areas, due to the correction for residual blood FDG activity. PET FDG activity correlated with macrophage content within aortic atherosclerosis. This imaging approach might serve as a useful non-invasive imaging technique and potentially permit monitoring of relative changes in inflammation within the atherosclerotic lesion
Oxidized low-density lipoproteins may induce expression of monocyte chemotactic protein-3 in atherosclerotic plaques
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Genes induced or suppressed by oxidized low-density lipoproteins (oxLDL) in human monocytic THP-1 cells were searched using the differential display reverse transcriptase polymerase chain reaction. One of the differentially expressed (up-regulated) cDNA fragments was found to contain sequences corresponding to monocyte chemotactic protein-3 (MCP-3). The stimulatory effect of the oxLDL on the expression of MCP-3 mRNA was both time- and dose-dependent. Treatment with GF109203X and genistein, inhibitors of protein kinase C and tyrosine kinase, respectively, had no effect on the induction of MCP-3 mRNA by oxLDL, while treatment with cycloheximide inhibited the induction. The induction was reproduced by the lipid components in oxLDL such as 9-HODE and 13-HODE, which are known to activate the peroxisome proliferator-activated receptor γ (PPARγ). Introduction of an endogenous PPARγ ligand, 15d-PGJ2, in the culture of THP-1 cells resulted in the induction of MCP-3 gene expression. Furthermore, analyses of human atherosclerotic plaques revealed that the expressional pattern of MCP-3 in the regions of neointimal and necrotic core overlapped with that of PPARγ. These results suggest that oxLDL delivers its signal for MCP-3 expression via PPARγ, which may be further related to the atherogenesis
Inhibition of lipoprotein-associated phospholipase A2 reduces complex coronary atherosclerotic plaque development
Wilensky, Robert L; Shi, Yi; Mohler, Emile R; Hamamdzic, Damir; Burgert, Mark E; Li, Jun; Postle, Anthony; Fenning, Robert S; Bollinger, James G; Hoffman, Bryan E; Pelchovitz, Daniel J; Yang, Jisheng; Mirabile, Rosanna C; Webb, Christine L; Zhang, LeFeng; Zhang, Ping; Gelb, Michael H; Walker, Max C; Zalewski, Andrew; Macphee, Colin H
Increased lipoprotein-associated phospholipase A2 (Lp-PLA2) activity is associated with increased risk of cardiac events, but it is not known whether Lp-PLA2 is a causative agent. Here we show that selective inhibition of Lp-PLA2 with darapladib reduced development of advanced coronary atherosclerosis in diabetic and hypercholesterolemic swine. Darapladib markedly inhibited plasma and lesion Lp-PLA2 activity and reduced lesion lysophosphatidylcholine content. Analysis of coronary gene expression showed that darapladib exerted a general anti-inflammatory action, substantially reducing the expression of 24 genes associated with macrophage and T lymphocyte functioning. Darapladib treatment resulted in a considerable decrease in plaque area and, notably, a markedly reduced necrotic core area and reduced medial destruction, resulting in fewer lesions with an unstable phenotype. These data show that selective inhibition of Lp-PLA2 inhibits progression to advanced coronary atherosclerotic lesions and confirms a crucial role of vascular inflammation independent from hypercholesterolemia in the development of lesions implicated in the pathogenesis of myocardial infarction and stroke. PMID:18806801
Calculation of arterial wall temperature in atherosclerotic arteries: effect of pulsatile flow, arterial geometry, and plaque structure
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Kim Taehong
Full Text Available Abstract Background This paper presents calculations of the temperature distribution in an atherosclerotic plaque experiencing an inflammatory process; it analyzes the presence of hot spots in the plaque region and their relationship to blood flow, arterial geometry, and inflammatory cell distribution. Determination of the plaque temperature has become an important topic because plaques showing a temperature inhomogeneity have a higher likelihood of rupture. As a result, monitoring plaque temperature and knowing the factors affecting it can help in the prevention of sudden rupture. Methods The transient temperature profile in inflamed atherosclerotic plaques is calculated by solving an energy equation and the Navier-Stokes equations in 2D idealized arterial models of a bending artery and an arterial bifurcation. For obtaining the numerical solution, the commercial package COMSOL 3.2 was used. The calculations correspond to a parametric study where arterial type and size, as well as plaque geometry and composition, are varied. These calculations are used to analyze the contribution of different factors affecting arterial wall temperature measurements. The main factors considered are the metabolic heat production of inflammatory cells, atherosclerotic plaque length lp, inflammatory cell layer length lmp, and inflammatory cell layer thickness dmp. Results The calculations indicate that the best location to perform the temperature measurement is at the back region of the plaque (0.5 ≤ l/lp ≤ 0.7. The location of the maximum temperature, or hot spot, at the plaque surface can move during the cardiac cycle depending on the arterial geometry and is a direct result of the blood flow pattern. For the bending artery, the hot spot moves 0.6 millimeters along the longitudinal direction; for the arterial bifurcation, the hot spot is concentrated at a single location due to the flow recirculation observed at both ends of the plaque. Focusing on the
Vulnerability of atherosclerotic plaques is associated with type I interferon in a murine model of lupus and atherosclerosis.
Zhang, C Y; Qu, B; Ye, P; Li, J; Bao, C D
This study aimed to investigate the relationship between type I interferon (IFN-I) and plaque stability in pristane-treated apolipoprotein E-knockout (ApoE(-/-)) mice. Antinuclear antibody (ANA) and extractable nuclear antigen antibody (ENA) levels were measured by immunofluorescence and enzyme-linked immunospot assay. Atherosclerotic plaques were detected by Sirius red/fast green staining. Cell apoptosis was detected by terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick-end labeling. Gene expression was determined by real-time PCR analyses. We found that pristane-treated ApoE(-/-) mice developed a lupus-like syndrome characterized by an increased production of serum ANA and ENA. Pristane treatment decreased the collagen content and increased the number of apoptotic cells in plaques. Moreover, IFN-induced ISG15, IFIT1-1, and IFIT1-2 gene expression was increased in peripheral blood cells and aortic plaques. An IFN-α-stimulated macrophage supernatant inhibited collagen type I, alpha 1 gene expression in vascular smooth muscle cells. We concluded that the vulnerability of plaques was associated with the activation of IFN-I in pristane-treated ApoE(-/-) mice. Thus, we speculated that the higher prevalence of cardiovascular events in patients with systemic lupus erythematosus could be due to plaque instability. PMID:26600548
Lipid volume fraction in atherosclerotic plaque phantoms classified under saline conditions by multispectral angioscopy at near-infrared wavelengths around 1200 nm.
Matsui, Daichi; Ishii, Katsunori; Awazu, Kunio
To identify high-risk atherosclerotic lesions, we require detailed information on the stability of atherosclerotic plaques. In this study, we quantitatively classified the lipid volume fractions in atherosclerotic plaque phantoms by a novel angioscope combined with near-infrared multispectral imaging. The multispectral angioscope was operated at peak absorption wavelengths of lipid in vulnerable plaques (1150, 1200, and 1300 nm) and at lower absorption wavelengths of water. The potential of the multispectral angioscope was demonstrated in atherosclerotic plaque phantoms containing 10-60 vol.% lipid and immersed in saline solution. The acquired multispectral data were processed by a spectral angle mapper algorithm, which enhanced the simulated plaque areas. Consequently, we classified the lipid volume fractions into five categories (0-5, 5-15, 15-30, 30-50, and 50-60 vol.%). Multispectral angioscopy at wavelengths around 1200 nm is a powerful tool for quantitatively evaluating the stability of atherosclerotic plaques based on the lipid volume fractions. PMID:26861978
Atherosclerotic plaque volume and composition in symptomatic carotid arteries assessed with multidetector CT angiography; relationship with severity of stenosis and cardiovascular risk factors
International Nuclear Information System (INIS)
The purpose of this study was to examine the volume and the composition of atherosclerotic plaque in symptomatic carotid arteries and to investigate the relationship between these plaque features and the severity of stenosis and the presence of cardiovascular risk factors. One hundred patients with cerebrovascular symptoms underwent CT angiography. We measured plaque volume (PV) and the relative contribution of plaque components (calcifications, fibrous tissue, and lipid) in the symptomatic artery. The contribution of different components was measured as the number of voxels within defined ranges of HU values (calcification >130 HU, fibrous tissue 60-130 HU, lipid core <60 HU). Fifty-seven patients had atherosclerotic plaque in the symptomatic carotid artery. The severity of stenosis and PV were moderately correlated. Age and smoking were independently related to PV. Patients with hypercholesterolemia had significantly less lipid and more calcium in their plaques than patients without hypercholesterolemia. Other cardiovascular risk factors were not significantly related to PV or plaque composition. Luminal stenosis of the carotid artery partly reflects the amount of atherosclerotic carotid disease. Plaque volume and plaque composition are associated with cardiovascular risk factors. (orig.)
Atherosclerotic plaque volume and composition in symptomatic carotid arteries assessed with multidetector CT angiography; relationship with severity of stenosis and cardiovascular risk factors
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Rozie, S.; Weert, T.T. de; Monye, C. de; Homburg, P.J.; Tanghe, H.L.J.; Lugt, A. van der [Erasmus MC, University Medical Center Rotterdam, Departments of Radiology, Rotterdam (Netherlands); Dippel, D.W.J. [Erasmus MC, University Medical Center Rotterdam, Department of Neurology, PO Box 2040, Rotterdam (Netherlands)
The purpose of this study was to examine the volume and the composition of atherosclerotic plaque in symptomatic carotid arteries and to investigate the relationship between these plaque features and the severity of stenosis and the presence of cardiovascular risk factors. One hundred patients with cerebrovascular symptoms underwent CT angiography. We measured plaque volume (PV) and the relative contribution of plaque components (calcifications, fibrous tissue, and lipid) in the symptomatic artery. The contribution of different components was measured as the number of voxels within defined ranges of HU values (calcification >130 HU, fibrous tissue 60-130 HU, lipid core <60 HU). Fifty-seven patients had atherosclerotic plaque in the symptomatic carotid artery. The severity of stenosis and PV were moderately correlated. Age and smoking were independently related to PV. Patients with hypercholesterolemia had significantly less lipid and more calcium in their plaques than patients without hypercholesterolemia. Other cardiovascular risk factors were not significantly related to PV or plaque composition. Luminal stenosis of the carotid artery partly reflects the amount of atherosclerotic carotid disease. Plaque volume and plaque composition are associated with cardiovascular risk factors. (orig.)
Selective removal of atherosclerotic plaque with a quantum cascade laser in the 5.7 µm wavelength range
International Nuclear Information System (INIS)
Atherosclerotic plaques consist mainly of cholesteryl esters, and the C=O stretching vibration mode of cholesteryl esters strongly absorbs radiation at a wavelength of 5.75 µm. For clinical application of less-invasive laser angioplasty with 5.75 µm, a compact laser is required. Quantum cascade lasers (QCLs) are semiconductor lasers that can emit radiation in the mid-IR range. In this study, the potential of the QCL for less-invasive laser angioplasty was evaluated. At the average power density of 180 W/cm2, the atherosclerotic aorta was ablated for the irradiation time of 1 s or more, whereas the normal aorta was ablated for more than 10 s. This demonstrates that selective ablation of the atherosclerotic aorta was achieved. However, strong coagulation and carbonization were observed. For reducing thermal effects, improving the pulse structure is required. In conclusion, the QCL achieved the selective ablation of the atherosclerotic lesions, which indicates the potential of the QCL. (author)
Selective removal of atherosclerotic plaque with a quantum cascade laser in the 5.7 µm wavelength range
Hashimura, Keisuke; Ishii, Katsunori; Awazu, Kunio
Atherosclerotic plaques consist mainly of cholesteryl esters, and the C=O stretching vibration mode of cholesteryl esters strongly absorbs radiation at a wavelength of 5.75 µm. For clinical application of less-invasive laser angioplasty with 5.75 µm, a compact laser is required. Quantum cascade lasers (QCLs) are semiconductor lasers that can emit radiation in the mid-IR range. In this study, the potential of the QCL for less-invasive laser angioplasty was evaluated. At the average power density of 180 W/cm2, the atherosclerotic aorta was ablated for the irradiation time of 1 s or more, whereas the normal aorta was ablated for more than 10 s. This demonstrates that selective ablation of the atherosclerotic aorta was achieved. However, strong coagulation and carbonization were observed. For reducing thermal effects, improving the pulse structure is required. In conclusion, the QCL achieved the selective ablation of the atherosclerotic lesions, which indicates the potential of the QCL.
Comparison between MDCT and Grayscale IVUS in a Quantitative Analysis of Coronary Lumen in Segments with or without Atherosclerotic Plaques
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Falcão, João L. A. A.; Falcão, Breno A. A. [Heart Institute (InCor), University of São Paulo Medical School (USP), São Paulo, SP (Brazil); Gurudevan, Swaminatha V. [Cedars-Sinai Heart Institute, Los Angeles, California, USA (United States); Campos, Carlos M.; Silva, Expedito R.; Kalil-Filho, Roberto; Rochitte, Carlos E.; Shiozaki, Afonso A.; Coelho-Filho, Otavio R.; Lemos, Pedro A. [Heart Institute (InCor), University of São Paulo Medical School (USP), São Paulo, SP (Brazil)
The diagnostic accuracy of 64-slice MDCT in comparison with IVUS has been poorly described and is mainly restricted to reports analyzing segments with documented atherosclerotic plaques. We compared 64-slice multidetector computed tomography (MDCT) with gray scale intravascular ultrasound (IVUS) for the evaluation of coronary lumen dimensions in the context of a comprehensive analysis, including segments with absent or mild disease. The 64-slice MDCT was performed within 72 h before the IVUS imaging, which was obtained for at least one coronary, regardless of the presence of luminal stenosis at angiography. A total of 21 patients were included, with 70 imaged vessels (total length 114.6 ± 38.3 mm per patient). A coronary plaque was diagnosed in segments with plaque burden > 40%. At patient, vessel, and segment levels, average lumen area, minimal lumen area, and minimal lumen diameter were highly correlated between IVUS and 64-slice MDCT (p < 0.01). However, 64-slice MDCT tended to underestimate the lumen size with a relatively wide dispersion of the differences. The comparison between 64-slice MDCT and IVUS lumen measurements was not substantially affected by the presence or absence of an underlying plaque. In addition, 64-slice MDCT showed good global accuracy for the detection of IVUS parameters associated with flow-limiting lesions. In a comprehensive, multi-territory, and whole-artery analysis, the assessment of coronary lumen by 64-slice MDCT compared with coronary IVUS showed a good overall diagnostic ability, regardless of the presence or absence of underlying atherosclerotic plaques.
Clinical feasibility of 3D automated coronary atherosclerotic plaque quantification algorithm on coronary computed tomography angiography: Comparison with intravascular ultrasound
International Nuclear Information System (INIS)
To evaluate the diagnostic performance of automated coronary atherosclerotic plaque quantification (QCT) by different users (expert/non-expert/automatic). One hundred fifty coronary artery segments from 142 patients who underwent coronary computed tomography angiography (CCTA) and intravascular ultrasound (IVUS) were analyzed. Minimal lumen area (MLA), maximal lumen area stenosis percentage (%AS), mean plaque burden percentage (%PB), and plaque volume were measured semi-automatically by expert, non-expert, and fully automatic QCT analyses, and then compared to IVUS. Between IVUS and expert QCT analysis, the correlation coefficients (r) for the MLA, %AS, %PB, and plaque volume were excellent: 0.89 (p < 0.001), 0.84 (p < 0.001), 0.91 (p < 0.001), and 0.94 (p < 0.001), respectively. There were no significant differences in the mean parameters (all p values >0.05) except %AS (p = 0.01). The automatic QCT analysis showed comparable performance to non-expert QCT analysis, showing correlation coefficients (r) of the MLA (0.80 vs. 0.82), %AS (0.82 vs. 0.80), %PB (0.84 vs. 0.73), and plaque volume (0.84 vs. 0.79) when they were compared to IVUS, respectively. Fully automatic QCT analysis showed clinical utility compared with IVUS, as well as a compelling performance when compared with semiautomatic analyses. (orig.)
Clinical feasibility of 3D automated coronary atherosclerotic plaque quantification algorithm on coronary computed tomography angiography: Comparison with intravascular ultrasound
Energy Technology Data Exchange (ETDEWEB)
Park, Hyung-Bok [Yonsei University Health System, Yonsei-Cedar Sinai Integrative Cardiovascular Imaging Research Center, Seoul (Korea, Republic of); Myongji Hospital, Division of Cardiology, Cardiovascular Center, Goyang (Korea, Republic of); Lee, Byoung Kwon [Yonsei University College of Medicine, Division of Cardiology, Gangnam Severance Hospital, Seoul (Korea, Republic of); Shin, Sanghoon [Yonsei University Health System, Yonsei-Cedar Sinai Integrative Cardiovascular Imaging Research Center, Seoul (Korea, Republic of); National Health Insurance Corporation Ilsan Hospital, Division of Cardiology, Goyang (Korea, Republic of); Heo, Ran; Chang, Hyuk-Jae; Chung, Namsik [Yonsei University Health System, Yonsei-Cedar Sinai Integrative Cardiovascular Imaging Research Center, Seoul (Korea, Republic of); Yonsei University Health System, Division of Cardiology, Severance Cardiovascular Hospital, Seoul (Korea, Republic of); Arsanjani, Reza [Cedars-Sinai Medical Center, Departments of Imaging and Medicine, Cedars-Sinai Heart Institute, Los Angeles, CA (United States); Kitslaar, Pieter H. [Leiden University Medical Center, Department of Radiology, Division of Image Processing, Leiden (Netherlands); Medis medical Imaging Systems B.V., Leiden (Netherlands); Broersen, Alexander; Dijkstra, Jouke [Leiden University Medical Center, Department of Radiology, Division of Image Processing, Leiden (Netherlands); Ahn, Sung Gyun [Yonsei University Wonju Severance Christian Hospital, Division of Cardiology, Wonju (Korea, Republic of); Min, James K. [New York-Presbyterian Hospital, Institute for Cardiovascular Imaging, Weill-Cornell Medical College, New York, NY (United States); Hong, Myeong-Ki; Jang, Yangsoo [Yonsei University Health System, Division of Cardiology, Severance Cardiovascular Hospital, Seoul (Korea, Republic of)
To evaluate the diagnostic performance of automated coronary atherosclerotic plaque quantification (QCT) by different users (expert/non-expert/automatic). One hundred fifty coronary artery segments from 142 patients who underwent coronary computed tomography angiography (CCTA) and intravascular ultrasound (IVUS) were analyzed. Minimal lumen area (MLA), maximal lumen area stenosis percentage (%AS), mean plaque burden percentage (%PB), and plaque volume were measured semi-automatically by expert, non-expert, and fully automatic QCT analyses, and then compared to IVUS. Between IVUS and expert QCT analysis, the correlation coefficients (r) for the MLA, %AS, %PB, and plaque volume were excellent: 0.89 (p < 0.001), 0.84 (p < 0.001), 0.91 (p < 0.001), and 0.94 (p < 0.001), respectively. There were no significant differences in the mean parameters (all p values >0.05) except %AS (p = 0.01). The automatic QCT analysis showed comparable performance to non-expert QCT analysis, showing correlation coefficients (r) of the MLA (0.80 vs. 0.82), %AS (0.82 vs. 0.80), %PB (0.84 vs. 0.73), and plaque volume (0.84 vs. 0.79) when they were compared to IVUS, respectively. Fully automatic QCT analysis showed clinical utility compared with IVUS, as well as a compelling performance when compared with semiautomatic analyses. (orig.)
Atherosclerotic Plaque Inflammation Varies Between Vascular Sites and Correlates With Response to Inhibition of Lipoprotein‐Associated Phospholipase A2
Fenning, Robert S.; Burgert, Mark E.; Hamamdzic, Damir; Peyster, Eliot G.; Mohler, Emile R.; Kangovi, Shreya; Jucker, Beat M.; Lenhard, Stephen C.; Macphee, Colin H.; Wilensky, Robert L.
Background Despite systemic exposure to risk factors, the circulatory system develops varying patterns of atherosclerosis for unclear reasons. In a porcine model, we investigated the relationship between site‐specific lesion development and inflammatory pathways involved in the coronary arteries (CORs) and distal abdominal aortas (AAs). Methods and Results Diabetes mellitus (DM) and hypercholesterolemia (HC) were induced in 37 pigs with 3 healthy controls. Site‐specific plaque development was studied by comparing plaque severity, macrophage infiltration, and inflammatory gene expression between CORs and AAs of 17 DM/HC pigs. To assess the role of lipoprotein‐associated phospholipase A2 (Lp‐PLA2) in plaque development, 20 DM/HC pigs were treated with the Lp‐PLA2 inhibitor darapladib and compared with the 17 DM/HC untreated pigs. DM/HC caused site‐specific differences in plaque severity. In the AAs, normalized plaque area was 4.4‐fold higher (P<0.001) and there were more fibroatheromas (9 of the 17 animals had a fibroatheroma in the AA and not the COR, P=0.004), while normalized macrophage staining area was 1.5‐fold higher (P=0.011) compared with CORs. DM/HC caused differential expression of 8 of 87 atherosclerotic genes studied, including 3 important in inflammation with higher expression in the CORs. Darapladib‐induced attenuation of normalized plaque area was site‐specific, as CORs responded 2.9‐fold more than AAs (P=0.045). Conclusions While plaque severity was worse in the AAs, inflammatory genes and inflammatory pathways that use Lp‐PLA2 were more important in the CORs. Our results suggest fundamental differences in inflammation between vascular sites, an important finding for the development of novel anti‐inflammatory therapeutics. PMID:25672369
Characteristics of carotid atherosclerotic plaques of chronic lipid apheresis patients as assessed by In Vivo High-Resolution CMR - a comparative analysis
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Grimm Jochen M
Full Text Available Abstract Background Components of carotid atherosclerotic plaques can reliably be identified and quantified using high resolution in vivo 3-Tesla CMR. It is suspected that lipid apheresis therapy in addition to lowering serum lipid levels also has an influence on development and progression of atherosclerotic plaques. The purpose of this study was to evaluate the influence of chronic lipid apheresis (LA on the composition of atherosclerotic carotid plaques. Methods 32 arteries of 16 patients during chronic LA-therapy with carotid plaques and stenosis of 1–80% were matched according to degree of stenosis with 32 patients, who had recently suffered an ischemic stroke. Of these patients only the asymptomatic carotid artery was analyzed. All patients underwent black-blood 3 T CMR of the carotids using parallel imaging and dedicated surface coils. Cardiovascular risk factors were recorded. Morphology and composition of carotid plaques were evaluated. For statistical evaluation Fisher's Exact and unpaired t-test were used. A p-value Results Patients in the LA-group were younger (63.5 vs. 73.9. years, p2, p Conclusion Results of this study suggest that, despite a severer risk profile for cardiovascular complications in LA-patients, chronic LA is associated with significantly lower lipid content in carotid plaques compared to plaques of patients without LA with similar degrees of stenosis, which is characteristic of clinically stable plaques.
Attenuation-based characterization of coronary atherosclerotic plaque: Comparison of dual source and dual energy CT with single-source CT and histopathology
International Nuclear Information System (INIS)
Objective: To compare different CT acquisition techniques regarding for attenuation-based characterization of coronary atherosclerotic plaques using histopathology as the standard of reference. Materials and methods: In a post mortem study 17 human hearts were studied with dual-source CT (DSCT) and dual energy CT (DECT) mode on a DSCT as well as with 16-slice single-source CT (SSCT). At autopsy, atherosclerotic lesions were cut at 5 μm sections. Histopathologic classification of the plaques according to the American Heart Association (AHA) criteria was performed by two pathologists. Attenuation values of all plaques were measured in DSCT, DECT and SSCT studies, respectively and classified based on attenuation according to modified AHA criteria. Results: 58 coronary plaques were identified at autopsy. Regardless of the CT technique only 52/58 plaques were found at CT (sensitivity = 89.6%). There was no significant difference between the mean attenuation values of different plaque types between DSCT, DECT, and SSCT: type IV: 11 HU/8 HU/19 HU; type Va: 44 HU/45 HU/52 HU; type Vb: 1088 HU/966 HU/1079 HU). The sensitivity for correct classification varied depending on the plaque type (type II = 0%, type III = 0%, type IV = 43%, type Va = 58%, Vb = 97%). Conclusion: Independent of the used acquisition technique, SSCT, DSCT and DECT show similar results for attenuation-based characterization of atherosclerotic coronary plaques.
Phage Display Identification of CD100 in Human Atherosclerotic Plaque Macrophages and Foam Cells
Luque, Maria Carolina Aquino; Gutierrez, Paulo Sampaio; Debbas, Victor; Martins, Waleska Kerllen; Puech-Leao, Pedro; Porto, Georgia; Coelho, Verônica; Boumsell, Laurence; Kalil, Jorge; Stolf, Beatriz
Atherosclerosis is a complex disease in which vessels develop plaques comprising dysfunctional endothelium, monocyte derived lipid laden foam cells and activated lymphocytes. Considering that humans and animal models of the disease develop quite distinct plaques, we used human plaques to search for proteins that could be used as markers of human atheromas. Phage display peptide libraries were probed to fresh human carotid plaques, and a bound phage homologous to plexin B1, a high affinity rec...
Evidence for roles of radicals in protein oxidation in advanced human atherosclerotic plaque
DEFF Research Database (Denmark)
Fu, S; Davies, Michael Jonathan; Stocker, R;
Oxidative damage might be important in atherogenesis. Oxidized lipids are present at significant concentrations in advanced human plaque, although tissue antioxidants are mostly present at normal concentrations. Indirect evidence of protein modification (notably derivatization of lysine) or...... close similarities in relative abundances in the latter two circumstances indicate that hydroxyl radical damage might occur in plaque. The relatively higher level of dityrosine in plaque than that observed after radiolysis suggests the additional involvement of HOCl-mediated reactions in advanced plaque....
Mast cell degranulator compound 48-80 promotes atherosclerotic plaque in apolipoprotein E knockout mice with perivascular common carotid collar placement
Institute of Scientific and Technical Information of China (English)
TANG Ya-ling; YANG Yong-zong; WANG Shuang; HUANG Tao; TANG Chao-ke; XU Zeng-xiang; SUN Yu-hui
Background Study of the relationship between mast cells and atherosclerosis is mostly dependent on pathological observation and cytology experiments. To investigate the effects of mast cells degranulation on plaque and their possible mechanisms we used apolipoprotein E knockout mice which had been placed perivascular common carotid collar with mast cells degranulator compound 48-80.Methods Forty apolipoprotein E knockout mice were fed a western-type diet and operated on with placement of perivascular right common carotid collar. Four weeks after surgery, the mice were intraperitoneally injected with compound 48-80 (0.5 mg/kg) or D-Hanks every other day for 4 times. The serum lipids and activity of tryptase were measured. Tissue sections were stained with hematoxylin and eosin. Corresponding sections were stained with toluidine blue and immunohistochemically with antibodies against macrophage-specific antigen, α-smooth muscle actin, interleukin-1β and van Willebrand factor. Simultaneously, basic fibroblast growth factor was detected by in situ hybridization and immunofluorescence.Results No pathological change was observed in common carotid non-collar placement but atherogenesis in common carotid collar placement of both groups. There was a significant increase in plaque area ((5.85±0.75)×104 vs (0.86±0.28)×104 μm2, P<0.05), the degree of lumen stenosis ((81±15)% vs (41±12)%, P <0.05), the activity of tryptase in serum ((0.57±0.13) U/L vs (0.36±0.10) U/L, P <0.05), and the percentage of degranulated mast cells ((80.6±17.8)% vs (13.5±4.1)%, P <0.05). The expressions of macrophage-specific antigen, α-smooth muscle actin, interleukin-1β, basic fibroblast growth factor and the density of neovessel in plaque were more in the compound 48-80 group than in the control group.Conclusions Perivascular common carotid collar placement can promote atherosclerotic plaque formation in apolipoprotein E knockout mice. Compound 48-80 increases plaque area and the degree
Aortic atherosclerotic plaque detection using a multiwavelength handheld photoacoustic imaging system
Hirano, Susumu; Namita, Takeshi; Kondo, Kengo; Yamakawa, Makoto; Shiina, Tsuyoshi
Patients affected by diseases caused by arteriosclerosis are increasing. Atherosclerosis, which is becoming an especially difficult health problem, forms plaques from lipids such as cholesterol located in walls of the aorta, cerebral artery, and coronary artery. Because lipid-rich plaques are vulnerable and because arterial rupture causes acute vascular occlusion, early detection is crucially important to prevent plaque growth and rupture. Ultrasound systems can detect plaques but cannot discriminate between vulnerable and equable plaques. To evaluate plaques non-invasively and easily, we developed a handheld photoacoustic imaging device. Its usefulness was verified in phantom experiments with a bovine aorta in which mimic plaque had been embedded. Photoacoustic images taken at wavelengths that produce high light absorbance by lipids show strong photoacoustic signals from the boundary of the mimic plaque. Results confirmed that our system can evaluate plaque properties by analysis with the photoacoustic spectrum. The effects of surrounding tissues and tissue components on plaque evaluation were investigated using a layered phantom. The mimic plaque located under a 6 mm blood layer was also evaluated. Results of these analyses demonstrate the system's usefulness.
Data on the lipoprotein (a), coronary atherosclerotic burden and vulnerable plaque phenotype in angiographic obstructive coronary artery disease.
Niccoli, Giampaolo; Chin, Diana; Scalone, Giancarla; Panebianco, Mario; Abbolito, Sofia; Cosentino, Nicola; Jacoangeli, Francesca; Refaat, Hesham; Gallo, Giovanna; Salerno, Gerardo; Volpe, Massimo; Crea, Filippo; De Biase, Luciano
Lipoprotein Lp(a) represents an independent risk factor for coronary artery disease (CAD). However, its association with CAD burden and lipid rich plaques prone to rupture in patients with acute coronary syndrome (ACS) still remains unknown. These data aim to investigate the association among serum Lipoprotein(a) (Lpa) levels, coronary atherosclerotic burden and features of culprit plaque in patients with ACS and obstructive CAD. For his reason, a total of 500 ACS patients were enrolled for the angiographic cohort and 51 ACS patients were enrolled for the optical coherence tomography (OCT) cohort. Angiographic CAD severity was assessed by Sullivan score and by Bogaty score including stenosis score and extent index, whereas OCT plaque features were evaluated at the site of the minimal lumen area and along the culprit segment. In the angiographic cohort, Lp(a) was a weak independent predictor of Sullivan score (p30 md/dl) compared to patients with lower Lp(a) levels (<30 md/dl) exhibited a higher prevalence of lipidic plaque at the site of the culprit stenosis (P=0.02), a wider lipid arc (p=0.003) and a higher prevalence of thin-cap fibroatheroma (p=0.004). PMID:27158659
Rate of Atherosclerotic Plaque Formation Predicts Cardiovascular Events in ESRD
Benedetto, Francesco Antonio; Tripepi, Giovanni; Mallamaci, Francesca; Zoccali, Carmine
Carotid intima media thickness (IMT) is a strong, independent predictor of cardiovascular events in both the general population and among those with end-stage renal disease (ESRD), but it is unknown whether changes in IMT or other ultrasound-measured indicators of atherosclerosis over time provide additional prognostic information. The progression of atherosclerosis with carotid ultrasound was followed in a cohort of 135 ESRD patients, 103 of whom had a repeat ultrasound after 15 mo of follow...
Characterising human atherosclerotic carotid plaque tissue composition and morphology using combined spectroscopic and imaging modalities.
Barrett, Hilary E; Mulvihill, John J; Cunnane, Eoghan M; Walsh, Michael T
Calcification is a marked pathological component in carotid artery plaque. Studies have suggested that calcification may induce regions of high stress concentrations therefore increasing the potential for rupture. However, the mechanical behaviour of the plaque under the influence of calcification is not fully understood. A method of accurately characterising the calcification coupled with the associated mechanical plaque properties is needed to better understand the impact of calcification on the mechanical behaviour of the plaque during minimally invasive treatments. This study proposes a comparison of biochemical and structural characterisation methods of the calcification in carotid plaque specimens to identify plaque mechanical behaviour. Biochemical analysis, by Fourier Transform Infrared (FTIR) spectroscopy, was used to identify the key components, including calcification, in each plaque sample. However, FTIR has a finite penetration depth which may limit the accuracy of the calcification measurement. Therefore, this FTIR analysis was coupled with the identification of the calcification inclusions located internally in the plaque specimen using micro x-ray computed tomography (μX-CT) which measures the calcification volume fraction (CVF) to total tissue content. The tissue characterisation processes were then applied to the mechanical material plaque properties acquired from experimental circumferential loading of human carotid plaque specimen for comparison of the methods. FTIR characterised the degree of plaque progression by identifying the functional groups associated with lipid, collagen and calcification in each specimen. This identified a negative relationship between stiffness and 'lipid to collagen' and 'calcification to collagen' ratios. However, μX-CT results suggest that CVF measurements relate to overall mechanical stiffness, while peak circumferential strength values may be dependent on specific calcification geometries. This study
Characterising human atherosclerotic carotid plaque tissue composition and morphology using combined spectroscopic and imaging modalities
Barrett, Hilary E; Mulvihill, John J.; Cunnane, Eoghan M; Walsh, Michael T
Calcification is a marked pathological component in carotid artery plaque. Studies have suggested that calcification may induce regions of high stress concentrations therefore increasing the potential for rupture. However, the mechanical behaviour of the plaque under the influence of calcification is not fully understood. A method of accurately characterising the calcification coupled with the associated mechanical plaque properties is needed to better understand the impact of ...
In-vivo quantitative T2 mapping of carotid arteries in atherosclerotic patients: segmentation and T2 measurement of plaque components
Biasiolli, Luca; Lindsay, Alistair C.; Chai, Joshua T.; Choudhury, Robin P.; Robson, Matthew D
Background Atherosclerotic plaques in carotid arteries can be characterized in-vivo by multicontrast cardiovascular magnetic resonance (CMR), which has been thoroughly validated with histology. However, the non-quantitative nature of multicontrast CMR and the need for extensive post-acquisition interpretation limit the widespread clinical application of in-vivo CMR plaque characterization. Quantitative T2 mapping is a promising alternative since it can provide absolute physical measurements o...
The relationship of the gene polymorphisms of matrix metalloproteinase-1, -2, -3 and -9 to the progression of coronary atherosclerotic plaque
International Nuclear Information System (INIS)
Objective: To evaluate the influence of the gene polymorphisms of matrix metalloproteinase(mmp)-1, -2, -3 and -9 on coronary atherosclerotic plaque progression. Methods: During the period of January 2005-December 2008, 80 patients with coronary heart disease underwent two times coronary angiography at authors' hospital. Based on the angiographic findings, the patients were classified into plaque progression group (n = 31) and plaque non-progression group (n = 49). Coronary atherosclerotic plaque progression was arbitrarily defined as that the minimal lumen diameter (MLD) of coronary artery showed a decrease ≥ 0.4 mm on the second coronary angiography. The detailed history and clinical examination results were collected, including serum concentrations of lipid profiling, fasting glucose and hs-CRP. Genotypings for polymorphic variances of MMP-1 (-1607 G / GG), MMP-2 (-955 A / C), MMP-3 (-1612 5A / 6A ) and MMP-9 (-1562 C/T) were performed by polymerase chain reaction (PCR) and sequencing analysis in two groups. Comparison of the clinical characteristics and polymorphisms between two groups was made to assess their effects on coronary atherosclerotic plaque progression. Results: More female patients and patients with acute coronary syndrome (ACS) were noted in patients with plaque progression compare to those with no progression (41.9% vs. 18.4%, P < 0.05 and 77.4% vs. 46.3%, P < 0.01, respectively). The serum hs-CRP level also significantly increased in group with plaque progression (0.26 ± 0.44 mg / L vs. 0.02 ± 0.14 mg / L, P < 0.01). Multivariable logistic regression analysis revealed that serum hs-CRP concentration and ACS were independent risk factors of coronary atherosclerotic plaque progression (OR: 12.63,95% CI:1.45-110.29, P < 0.05 and OR:2.99,95% CI:1.04-8.63, P < 0.05, respectively). The frequencies of 6A / 6A genotype and 6A allele of MMP-3 promoter at location -1612 were significantly higher in group with plaque progression than that in group with
The Clinical Value of High-Intensity Signals on the Coronary Atherosclerotic Plaques: Noncontrast T1-Weighted Magnetic Resonance Imaging
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Shoichi Ehara
Full Text Available Over the past several decades, significant progress has been made in the pathohistological assessment of vulnerable plaques and in invasive intravascular imaging techniques. However, the assessment of plaque morphology by invasive modalities is of limited value for the detection of subclinical coronary atherosclerosis and the subsequent prediction or prevention of acute cardiovascular events. Recently, magnetic resonance (MR imaging technology has reached a sufficient level of spatial resolution, which allowed the plaque visualization of large and static arteries such as the carotids and aorta. However, coronary wall imaging by MR is still challenging due to the small size of coronary arteries, cardiac and respiratory motion, and the low contrast-to-noise ratio between the coronary artery wall and the surrounding structures. Following the introduction of carotid plaque imaging with noncontrast T1-weighted imaging (T1WI, some investigators have reported that coronary artery high-intensity signals on T1WI are associated with vulnerable plaque morphology and an increased risk of future cardiac events. Although there are several limitations and issues that need to be resolved, this novel MR technique for coronary plaque imaging could influence treatment strategies for atherothrombotic disease and may be useful for understanding the pathophysiological mechanisms of atherothrombotic plaque formation.
Controlling the angiogenic switch in developing atherosclerotic plaques: Possible targets for therapeutic intervention
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Slevin Mark
Full Text Available Abstract Plaque angiogenesis may have an important role in the development of atherosclerosis. Vasa vasorum angiogenesis and medial infiltration provides nutrients to the developing and expanding intima and therefore, may prevent cellular death and contribute to plaque growth and stabilization in early lesions. However in more advanced plaques, inflammatory cell infiltration, and concomitant production of numerous pro-angiogenic cytokines may be responsible for induction of uncontrolled neointimal microvessel proliferation resulting in production of immature and fragile neovessels similar to that seen in tumour development. These could contribute to development of an unstable haemorrhagic rupture-prone environment. Increasing evidence has suggested that the expression of intimal neovessels is directly related to the stage of plaque development, the risk of plaque rupture, and subsequently, the presence of symptomatic disease, the timing of ischemic neurological events and myocardial/cerebral infarction. Despite this, there is conflicting evidence regarding the causal relationship between neovessel expression and plaque thrombosis with some in vivo experimental models suggesting the contrary and as yet, few direct mediators of angiogenesis have been identified and associated with plaque instability in vivo. In recent years, an increasing number of angiogenic therapeutic targets have been proposed in order to facilitate modulation of neovascularization and its consequences in diseases such as cancer and macular degeneration. A complete knowledge of the mechanisms responsible for initiation of adventitial vessel proliferation, their extension into the intimal regions and possible de-novo synthesis of neovessels following differentiation of bone-marrow-derived stem cells is required in order to contemplate potential single or combinational anti-angiogenic therapies. In this review, we will examine the importance of angiogenesis in complicated plaque
Chlamydia pneumoniae in atherosclerotic carotid artery plaques: high prevalence among heavy smokers.
Dobrilovic, N; Vadlamani, L; Meyer, M; Wright, C B
This study was designed to determine the prevalence of Chlamydia pneumoniae in carotid artery plaques. Although there have been numerous studies evaluating coronary plaques for this bacterium fewer studies have assessed noncoronary vasculature. In addition we wished to evaluate whether correlation exists between the presence of C. pneumoniae in carotid plaques and established risk factors for atherosclerosis. Sixty intact carotid artery plaques removed during surgery (carotid endarterectomy) were formalin-fixed and paraffin-embedded according to conventional techniques. These samples were evaluated by polymerase chain reaction analysis to detect presence of C. pneumoniae DNA. Results were tabulated and compared against established risk factors for atherosclerosis: diabetes, hypertension, hyperlipidemia, age, and smoking. Forty-two (70.0%) of the 60 plaques that were evaluated tested positive for the presence of C. pneumoniae DNA by polymerase chain reaction analysis. In the sample defined as being from heavy smokers (greater than 15-pack-year history) 33 (94.3%) of 35 plaques tested positive whereas two (5.7%) tested negative. This correlation demonstrated statistical significance (P = 1.36 x 10(-6), two-tailed Fisher exact test). Presence of C. pneumoniae in carotid plaques demonstrated no statistically significant correlation with diabetes, hypertension, or hyperlipidemia. Age as a risk factor was examined but not statistically evaluated because of the narrow range within our patient sample. Analysis of the data reveals that C. pneumoniae is present in large numbers of atheromatous plaques as is consistent with emerging data. What is interesting though is that 33 (94.3%) of the 35 smokers had plaques that tested positive for the bacterium as opposed to only nine (36.0%) of the 25 nonsmokers. Identification of specific populations exhibiting a high prevalence of C. pneumoniae may serve to focus future studies. Ongoing investigation will seek to determine whether C
Repeatability of in vivo quantification of atherosclerotic carotid artery plaque components by supervised multispectral classification
Gao, Shan; van 't Klooster, Ronald; van Wijk, Diederik F.; Nederveen, Aart J.; Lelieveldt, Boudewijn P.F.; van der Geest, Rob J.
Objective To evaluate the agreement and scan–rescan repeatability of automated and manual plaque segmentation for the quantification of in vivo carotid artery plaque components from multi-contrast MRI. Materials and methods Twenty-three patients with 30–70 % stenosis underwent two 3T MR carotid vessel wall exams within a 1 month interval. T1w, T2w, PDw and TOF images were acquired around the region of maximum vessel narrowing. Manual delineation of the vessel wall and plaque components (lipid...
Impaired gait pattern as a sensitive tool to assess hypoxic brain damage in a novel mouse model of atherosclerotic plaque rupture
Roth, Lynn; Van Dam, Debby; Van der Donckt, Carole; Schrijvers, Dorien M.; Lemmens, Katrien; Van Brussel, Ilse; De Deyn, Peter P.; Martinet, Wim; De Meyer, Guido R. Y.
Apolipoprotein E deficient (ApoE(-/-)) mice with abeterozygous mutation in the flbrillin-1 gene (Fbn1(C1039G+/-) show spontaneous atherosclerotic plaque ruptures, disturbances in cerebral flow and sudden death when fed a Western-type diet (WD). The present study focused on motor coordination and spa
Painting blood vessels and atherosclerotic plaques with an adhesive drug depot
Kastrup, Christian J.; Nahrendorf, Matthias; Figueiredo, Jose Luiz; Lee, Haeshin; Kambhampati, Swetha; Lee, Timothy; Cho, Seung-Woo; Gorbatov, Rostic; Iwamoto, Yoshiko; Dang, Tram T.; Dutta, Partha; Yeon, Ju Hun; Cheng, Hao; Pritchard, Christopher D.; Vegas, Arturo J.; Siegel, Cory D.; MacDougall, Samantha; Okonkwo, Michael; Thai, Anh; Stone, James R.; Coury, Arthur J.; Weissleder, Ralph; Langer, Robert; Anderson, Daniel G.
The treatment of diseased vasculature remains challenging, in part because of the difficulty in implanting drug-eluting devices without subjecting vessels to damaging mechanical forces. Implanting materials using adhesive forces could overcome this challenge, but materials have previously not been shown to durably adhere to intact endothelium under blood flow. Marine mussels secrete strong underwater adhesives that have been mimicked in synthetic systems. Here we develop a drug-eluting bioadhesive gel that can be locally and durably glued onto the inside surface of blood vessels. In a mouse model of atherosclerosis, inflamed plaques treated with steroid-eluting adhesive gels had reduced macrophage content and developed protective fibrous caps covering the plaque core. Treatment also lowered plasma cytokine levels and biomarkers of inflammation in the plaque. The drug-eluting devices developed here provide a general strategy for implanting therapeutics in the vasculature using adhesive forces and could potentially be used to stabilize rupture-prone plaques. PMID:23236189
[Mycoplasma pneumoniae and Chlamydia pneumoniae are associated to inflammation and rupture of the atherosclerotic coronary plaques].
Ramires, José Antonio F; Higuchi, Maria de Lourdes
In this review we report recent findings of our lab showing that Mycoplasma pneumoniae and Chlamydia pneumoniae are present in higher amount, associated with adventitial inflammation and positive vessel remodeling, in thrombosed coronary artery segments (CAS) of patients who died due to acute myocardial infarction. CD8T cell was the predominant lymphocytes in the plaque and CD24(B) cell in the adventitia. The mean numbers of lymphocytes were significantly higher in adventitia than in the plaque. Vulnerable plaques were usually associated with focal positive vessel remodeling and large lipidic atheromas. Mycoplasma is the only bacterium that needs cholesterol for proliferation. We hypothesized that the association of Mycoplasma pneumoniae and Chlamydia pneumoniae increases virulence of both bacteria, inducing inflammation and rupture of the plaque. The search of CMV and Helicobacter pylori resulted negative. PMID:15626350
Biomechanics of atherosclerotic coronary plaque: site, stability and in vivo elasticity modeling.
Ohayon, Jacques; Finet, Gérard; Le Floc'h, Simon; Cloutier, Guy; Gharib, Ahmed M.; Heroux, Julie; Pettigrew, Roderic I.
International audience Coronary atheroma develop in local sites that are widely variable among patients and are considerably variable in their vulnerability for rupture. This article summarizes studies conducted by our collaborative laboratories on predictive biomechanical modeling of coronary plaques. It aims to give insights into the role of biomechanics in the development and localization of atherosclerosis, the morphologic features that determine vulnerable plaque stability, and emergi...
Carotid and femoral atherosclerotic plaques show different morphology. : Patterns of Peripheral Arterial Disease
Herisson, Fanny; Heymann, Marie-Françoise; Chétiveaux, Maud; Charrier, Céline; Battaglia, Séverine; Pilet, Paul; Rouillon, Thierry; Krempf, Michel; Lemarchand, Patricia; Heymann, Dominique; Gouëffic, Yann
OBJECTIVE: Results of endovascular repair vary according to the arterial bed. We hypothesized that these differences may be related to the plaque features. To explore this hypothesis, we designed a prospective study that compared carotid and femoral atheroma. METHODS AND RESULTS: Patients that underwent femoral or carotid endarterectomy were included in our study. Demographic data and blood sampling were obtained prior to surgery. Plaques were evaluated for AHA grading, calcification and lipi...
Detection of early stage atherosclerotic plaques using PET and CT fusion imaging targeting P-selectin in low density lipoprotein receptor-deficient mice
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Nakamura, Ikuko, E-mail: firstname.lastname@example.com [RIKEN Center for Molecular Imaging Science, Kobe (Japan); Department of Cardiovascular Medicine, Saga University, Saga (Japan); Hasegawa, Koki [RIKEN Center for Molecular Imaging Science, Kobe (Japan); Department of Pathology and Experimental Medicine, Kumamoto University, Kumamoto (Japan); Wada, Yasuhiro [RIKEN Center for Molecular Imaging Science, Kobe (Japan); Hirase, Tetsuaki; Node, Koichi [Department of Cardiovascular Medicine, Saga University, Saga (Japan); Watanabe, Yasuyoshi, E-mail: firstname.lastname@example.com [RIKEN Center for Molecular Imaging Science, Kobe (Japan)
Highlights: ► P-selectin regulates leukocyte recruitment as an early stage event of atherogenesis. ► We developed an antibody-based molecular imaging probe targeting P-selectin for PET. ► This is the first report on successful PET imaging for delineation of P-selectin. ► P-selectin is a candidate target for atherosclerotic plaque imaging by clinical PET. -- Abstract: Background: Sensitive detection and qualitative analysis of atherosclerotic plaques are in high demand in cardiovascular clinical settings. The leukocyte–endothelial interaction mediated by an adhesion molecule P-selectin participates in arterial wall inflammation and atherosclerosis. Methods and results: A {sup 64}Cu-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid conjugated anti-P-selectin monoclonal antibody ({sup 64}Cu-DOTA-anti-P-selectin mAb) probe was prepared by conjugating an anti-P-selectin monoclonal antibody with DOTA followed by {sup 64}Cu labeling. Thirty-six hours prior to PET and CT fusion imaging, 3 MBq of {sup 64}Cu-DOTA-anti-P-selectin mAb was intravenously injected into low density lipoprotein receptor-deficient Ldlr-/- mice. After a 180 min PET scan, autoradiography and biodistribution of {sup 64}Cu-DOTA-anti-P-selectin monoclonal antibody was examined using excised aortas. In Ldlr-/- mice fed with a high cholesterol diet for promotion of atherosclerotic plaque development, PET and CT fusion imaging revealed selective and prominent accumulation of the probe in the aortic root. Autoradiography of aortas that demonstrated probe uptake into atherosclerotic plaques was confirmed by Oil red O staining for lipid droplets. In Ldlr-/- mice fed with a chow diet to develop mild atherosclerotic plaques, probe accumulation was barely detectable in the aortic root on PET and CT fusion imaging. Probe biodistribution in aortas was 6.6-fold higher in Ldlr-/- mice fed with a high cholesterol diet than in those fed with a normal chow diet. {sup 64}Cu-DOTA-anti-P-selectin m
Association between albuminuria, atherosclerotic plaques, elevated pulse wave velocity, age, risk category and prognosis in apparently healthy individuals
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Greve, Sara V; Blicher, Marie K; Blyme, Adam;
, with moderate SCORE or with high-intermediate or high FRS (all P hazard ratio 2.7 (1.6-4.8)] and 61...... years [hazard ratio 2.7 (1.5-4.7)], moderate [hazard ratio 2.4 (1.6-3.7)] or high SCORE risk group [hazard ratio 2.3 (1.2-4.7)] and low-intermediate [hazard ratio 3.3 (1.5-7.0)], high-intermediate [hazard ratio 2.3 (1.5-3.5)] and high FRS risk group [hazard ratio 2.0 (1.4-3.0)]. CONCLUSION: SVD...... atherosclerotic plaques or albuminuria defined as urine albumin/creatinine ratio at least 90th percentile of 0.73/1.06 mg/mmol men/women. In 2006, the composite endpoint (CEP) of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke and hospitalization for ischemic heart disease was recorded (n...
99mTc-interleukin-2 scintigraphy for the in vivo imaging of vulnerable atherosclerotic plaques
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Several histopathological studies have demonstrated that vulnerable plaques are enriched in inflammatory cells. The aims of this study were: (1a) to test the ability of 99mTc-labelled interleukin-2 (99mTc-IL2) to bind to IL2R-positive (IL2R+) cells in carotid plaques and (1b) to correlate the plaque uptake of 99mTc-IL2, measured in vivo, with the number of IL2R+ cells within the plaque, measured ex vivo by histology (transversal study, TS), and (2) to evaluate changes in 99mTc-IL2 uptake in plaques, before and after treatment with a statin or a hypocholesterolaemic diet (longitudinal study, LS). Ultrasound scan was performed for plaque characterisation and localisation. Fourteen patients (16 plaques) eligible for endoarterectomy were recruited for the TS and underwent 99mTc-IL2 scintigraphy before surgery. Nine patients (13 plaques) were recruited for the LS; these patients received atorvastatin or a standard hypocholesterolaemic diet and 99mTc-IL2 scintigraphy was performed before and after 3 months of treatment. The degree of 99mTc-IL2 uptake was expressed as the plaque/background (T/B) ratio. In patients from TS, T/B ratios correlated with the percentage of IL2R+ cells at histology (r=0.707; p=0.002) and the number of IL2R+ cells at flow cytometry (r=0.711; p=0.006). No correlations were observed between ultrasound scores and either scintigraphic or histological findings. In patients from the LS, the mean 99mTc-IL2 uptake decreased in statin-treated patients (1.75±0.50 vs 2.16±0.44; p=0.012), while it was unchanged in the patients on the hypocholesterolaemic diet (2.33±0.45 vs 2.34±0.5). 99mTc-IL2 accumulates in vulnerable carotid plaques; this accumulation is correlated with the amount of IL2R+ cells and is influenced by lipid-lowering treatment with a statin. (orig.)
Detection of thrombosis and plaque rupture in atherosclerotic rabbit model by using 3.0 T MR imaging
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Objective: To explore the imaging of the thrombosis after pharmacological triggering of plaque rupture in atherosclerotic rabbit model by using 3.0 T high-resolution magnetic resonance imaging. Methods: Twenty male New Zealand white rabbits were divided into an experimental group (n=16) and a control group (n=4). The aortic wall injuries were induced by an intravascular balloon in experimental group rabbits after high cholesterol diet. The pharmacological triggering with Russell's viper venom and histamine was performed after 3 months of establishment of model. All of the animals underwent pre-trigger and post-trigger MR examinations including 3D time of fight (3D TOF), T1WI, T2WI and post contrast T1WI. Euthanasia was performed in all rabbits and gross anatomy and histological specimen of aorta were obtained. Comparing the location and length of the thrombus between MRI images and histopathology was used Pearson test. Comparing the calculated indexes of abdominal aorta between rabbits with and without thrombosis was used AVONA test and LSD-t test. Results: After triggering, 8 in 14 survived rabbits developed thrombosis in experimental group, meanwhile, no thrombus was found in control group. The accuracy of multi-sequences MRI for detecting of thrombus was 87.1% (27/31). MRI data correlated with the histopathology regarding thrombus length (r=0.85, P2 vs. (8.93±5.36) mm2, P<0.01]. Conclusion: MRI is useful tool to determine the thrombosis and plaque rupture in atherosclerotic rabbit model. (authors)
Upstream Transcription Factor 1 (USF1) allelic variants regulate lipoprotein metabolism in women and USF1 expression in atherosclerotic plaque
Fan, Yue-Mei; Hernesniemi, Jussi; Oksala, Niku; Levula, Mari; Raitoharju, Emma; Collings, Auni; Hutri-Kähönen, Nina; Juonala, Markus; Marniemi, Jukka; Lyytikäinen, Leo-Pekka; Seppälä, Ilkka; Mennander, Ari; Tarkka, Matti; Kangas, Antti J.; Soininen, Pasi; Salenius, Juha Pekka; Klopp, Norman; Illig, Thomas; Laitinen, Tomi; Ala-Korpela, Mika; Laaksonen, Reijo; Viikari, Jorma; Kähönen, Mika; Raitakari, Olli T.; Lehtimäki, Terho
Upstream transcription factor 1 (USF1) allelic variants significantly influence future risk of cardiovascular disease and overall mortality in females. We investigated sex-specific effects of USF1 gene allelic variants on serum indices of lipoprotein metabolism, early markers of asymptomatic atherosclerosis and their changes during six years of follow-up. In addition, we investigated the cis-regulatory role of these USF1 variants in artery wall tissues in Caucasians. In the Cardiovascular Risk in Young Finns Study, 1,608 participants (56% women, aged 31.9 ± 4.9) with lipids and cIMT data were included. For functional study, whole genome mRNA expression profiling was performed in 91 histologically classified atherosclerotic samples. In females, serum total, LDL cholesterol and apoB levels increased gradually according to USF1 rs2516839 genotypes TT < CT < CC and rs1556259 AA < AG < GG as well as according to USF1 H3 (GCCCGG) copy number 0 < 1 < 2. Furthermore, the carriers of minor alleles of rs2516839 (C) and rs1556259 (G) of USF1 gene had decreased USF1 expression in atherosclerotic plaques (P = 0.028 and 0.08, respectively) as compared to non-carriers. The genetic variation in USF1 influence USF1 transcript expression in advanced atherosclerosis and regulates levels and metabolism of circulating apoB and apoB-containing lipoprotein particles in sex-dependent manner, but is not a major determinant of early markers of atherosclerosis. PMID:24722012
The influence of inaccuracies in carotid MRI segmentation on atherosclerotic plaque stress computations.
Nieuwstadt, Harm A; Speelman, Lambert; Breeuwer, Marcel; van der Lugt, Aad; van der Steen, Anton F W; Wentzel, Jolanda J; Gijsen, Frank J H
Biomechanical finite element analysis (FEA) based on in vivo carotid magnetic resonance imaging (MRI) can be used to assess carotid plaque vulnerability noninvasively by computing peak cap stress. However, the accuracy of MRI plaque segmentation and the influence this has on FEA has remained unreported due to the lack of a reliable submillimeter ground truth. In this study, we quantify this influence using novel numerical simulations of carotid MRI. Histological sections from carotid plaques from 12 patients were used to create 33 ground truth plaque models. These models were subjected to numerical computer simulations of a currently used clinically applied 3.0 T T1-weighted black-blood carotid MRI protocol (in-plane acquisition voxel size of 0.62 × 0.62 mm2) to generate simulated in vivo MR images from a known underlying ground truth. The simulated images were manually segmented by three MRI readers. FEA models based on the MRI segmentations were compared with the FEA models based on the ground truth. MRI-based FEA model peak cap stress was consistently underestimated, but still correlated (R) moderately with the ground truth stress: R = 0.71, R = 0.47, and R = 0.76 for the three MRI readers respectively (p carotid plaques with thin caps, the current clinically used in-plane acquisition voxel size (∼0.6 mm) is inadequate. FEA plaque stress computations would be considerably more reliable if they would be used to identify thick-cap carotid plaques with low stresses instead. PMID:24317274
Cardiovascular magnetic resonance parameters of atherosclerotic plaque burden improve discrimination of prior major adverse cardiovascular events
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Bansilal Sameer
Full Text Available Abstract Aims Patients with prior major cardiovascular or cerebrovascular events (MACE are more likely to have future recurrent events independent of traditional cardiovascular disease risk factors. The purpose of this study was to determine if patients with traditional risk factors and prior MACE had increased cardiovascular magnetic resonance (CMR plaque burden measures compared to patients with risk factors but no prior events. Methods and Results Black blood carotid and thoracic aorta images were obtained from 195 patients using a rapid extended coverage turbo spin echo sequence. CMR measures of plaque burden were obtained by tracing lumen and outer vessel wall contours. Patients with prior MACE had significantly higher MR plaque burden (wall thickness, wall area and normalized wall index in carotids and thoracic aorta compared to those without prior MACE (Wall thickness carotids: 1.03 ± 0.03 vs. 0.93± 0.03, p = 0.001; SD wall thickness carotids: 0.137 ± 0.0008 vs. 0.102 ± 0.0004, p Conclusion A greater plaque burden and plaque eccentricity is prevalent among patients with prior MACE.
Quantification of [18F]-FDG uptake in atherosclerotic plaque. Impact of renal function
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Impaired renal function causes both increased and prolonged tracer availability in the blood-pool which might result in increased tracer accumulation in atherosclerotic lesions. Therefore, the aim of this study was to investigate a possible correlation between the intensity of tracer uptake in atherosclerotic lesions and renal function. Data from 50 [18F]-fluoro-2-deoxy-D-glucose (FDG) scans were visually evaluated for tracer uptake in vessel wall alterations. Lesions were analyzed semiquantitatively by determining the blood-pool standardized uptake values (SUVblood-pools), maximum SUVs (SUVmaxs), and the target-to-background ratio (TBR). These parameters were tested for correlation with estimated glomerular filtration rate (eGFR), and cardiovascular risk factors. Both SUVblood-pools (rs=-0.32, p=0.03) and SUVmaxs for [18F]-FDG (rs=-0.50, p18F]-FDG demonstrated a significant positive correlation with eGFRs (rs=0.21, p=0.02). This study found that both intravascular tracer availability (SUVblood-pool) and intralesional tracer uptake (SUVmax) are influenced by renal function. Calculation of TBR to account for that effect may result in overcorrection in case of [18F]-FDG. Renal insufficiency or subclinical changes in renal function have to be considered as a confounding factor in PET of atherosclerotic lesions. (author)
Effect of delmopinol hydrochloride mouthrinse on plaque formation and gingivitis in "rapid" and "slow" plaque formers.
Zee, K; Rundegren, J; Attström, R
The aim of the present study was to investigate differences in the plaque and gingivitis inhibiting effect of delmopinol rinsing between "rapid" and "slow" plaque formers. 23 subjects (12 "rapid" and 11 "slow" plaque formers) were selected from 71 healthy young adults. The selection was based on the plaque index on the buccal surfaces of all premolars and 1st molars after 3-days without plaque control. The 23 subjects were randomly assigned into 3 groups with different mouthrinses, i.e., 0.1% delmopinol, 0.2% delmopinol, and placebo. The study was double-blind with parallel design between the "rapid" and "slow" plaque formers and cross-over design between 2 active periods and a placebo period. Each rinsing period lasted for 5 days. During the 3 test periods, the subjects refrained from all oral hygiene and rinsed 2x daily with either one of the 3 solutions. Gingival crevicular fluid (GCF) was collected from buccal surfaces of upper canines and premolars and bleeding on probing (BOP) recorded at 6 sites around each tooth before and after each test period. Plaque assessment, including plaque index (PI) and standardized color slides for planimetric analyses obtained from the canines and premolars, were only recorded after each test period. Results showed that the mean PI and planimetry values for both the "rapid" and "slow" plaque formers were lower than the placebo, for either the 0.1% or the 0.2% delmopinol mouthrinse. The differences between the" rapid" and "slow" plaque formers were not statistically significant. There was a small reduction in BOP in both groups for the delmopinol periods, as against a slight increase in the placebo period; the difference between the placebo group and the 2 groups of plaque formers was not statistically significant (p>0.6 for both 0.1% and 0.2% delmopinol). Results suggested that both 0.1% and 0.2% delmopinol reduce plaque formation and gingivitis to a similar extent in subjects with extreme rates of plaque formation. PMID:9226389
Carotid ultrasound symptomatology using atherosclerotic plaque characterization: a class of Atheromatic systems.
Acharya, U Rajendra; S, Vinitha Sree; Molinari, Filippo; Saba, Luca; Nicolaides, Andrew; Shafique, Shoaib; Suri, Jasjit S
In this paper, we present a Computer Aided Diagnosis (CAD) based technique (Atheromatic system) for classification of carotid plaques in B-mode ultrasound images into symptomatic or asymptomatic classes. This system, called Atheromatic, has two steps: (i) feature extraction using a combination of Discrete Wavelet Transform (DWT) and averaging algorithms and (ii) classification using Support Vector Machine (SVM) classifier for automated decision making. The CAD system was built and tested using a database consisting of 150 asymptomatic and 196 symptomatic plaque regions of interests which were manually segmented. The ground truth of each plaque was determined based on the presence or absence of symptoms. Three-fold cross-validation protocol was adapted for developing and testing the classifiers. The SVM classifier with a polynomial kernel of order 2 recorded the highest classification accuracy of 83.7%. In the clinical scenario, such a technique, after much more validation, can be used as an adjunct tool to aid physicians by giving a second opinion on the nature of the plaque (symptomatic/asymptomatic) which would help in the more confident determination of the subsequent treatment regime for the patient. PMID:23366606
Influence of insonification angle on echogenicity of B-mode images of atherosclerotic plaque in vitro
DEFF Research Database (Denmark)
Wilhjelm, Jens E.; Jespersen, Søren Kragh; Hansen, J. U.; Nyssen, N.I.H.
) volts was calculated for the plaque region in each image. The standard deviation over the 48 MAL values were for each of the 7 angles between 0.12 V and 0.18 V. For each scan plane, the standard deviation was also calculated over the 7 images. The mean and standard deviation of these 48 numbers were 0...
Mathematical modelling of atheroma plaque formation and development in coronary arteries
Cilla, Myriam; Peña, Estefanía; Martínez, Miguel A.
Atherosclerosis is a vascular disease caused by inflammation of the arterial wall, which results in the accumulation of low-density lipoprotein (LDL) cholesterol, monocytes, macrophages and fat-laden foam cells at the place of the inflammation. This process is commonly referred to as plaque formation. The evolution of the atherosclerosis disease, and in particular the influence of wall shear stress on the growth of atherosclerotic plaques, is still a poorly understood phenomenon. This work presents a mathematical model to reproduce atheroma plaque growth in coronary arteries. This model uses the Navier–Stokes equations and Darcy's law for fluid dynamics, convection–diffusion–reaction equations for modelling the mass balance in the lumen and intima, and the Kedem–Katchalsky equations for the interfacial coupling at membranes, i.e. endothelium. The volume flux and the solute flux across the interface between the fluid and the porous domains are governed by a three-pore model. The main species and substances which play a role in early atherosclerosis development have been considered in the model, i.e. LDL, oxidized LDL, monocytes, macrophages, foam cells, smooth muscle cells, cytokines and collagen. Furthermore, experimental data taken from the literature have been used in order to physiologically determine model parameters. The mathematical model has been implemented in a representative axisymmetric geometrical coronary artery model. The results show that the mathematical model is able to qualitatively capture the atheroma plaque development observed in the intima layer. PMID:24196695
Mathematical modelling of atheroma plaque formation and development in coronary arteries.
Cilla, Myriam; Peña, Estefanía; Martínez, Miguel A
Atherosclerosis is a vascular disease caused by inflammation of the arterial wall, which results in the accumulation of low-density lipoprotein (LDL) cholesterol, monocytes, macrophages and fat-laden foam cells at the place of the inflammation. This process is commonly referred to as plaque formation. The evolution of the atherosclerosis disease, and in particular the influence of wall shear stress on the growth of atherosclerotic plaques, is still a poorly understood phenomenon. This work presents a mathematical model to reproduce atheroma plaque growth in coronary arteries. This model uses the Navier-Stokes equations and Darcy's law for fluid dynamics, convection-diffusion-reaction equations for modelling the mass balance in the lumen and intima, and the Kedem-Katchalsky equations for the interfacial coupling at membranes, i.e. endothelium. The volume flux and the solute flux across the interface between the fluid and the porous domains are governed by a three-pore model. The main species and substances which play a role in early atherosclerosis development have been considered in the model, i.e. LDL, oxidized LDL, monocytes, macrophages, foam cells, smooth muscle cells, cytokines and collagen. Furthermore, experimental data taken from the literature have been used in order to physiologically determine model parameters. The mathematical model has been implemented in a representative axisymmetric geometrical coronary artery model. The results show that the mathematical model is able to qualitatively capture the atheroma plaque development observed in the intima layer. PMID:24196695
Viorica CHETRUS; I.R. ION
The aim of this study was to present the most effective and easiest ways to diagnoze dental plaque, and to distin‐ guish some modern and effective methods for its removal. Materials and method. The study was performed on 34 patients aged between 19‐42 years. For dental plaque detection, the (QHT) index in two different ‐ initial and final – stages, was used. For the removal of sub‐gingival and supra‐gingival soft and hard deposits, scaling was used, as well as AIR FLOW professional brushing f...
Nuclear medicine and coronary artery disease: evaluation of tracers of myocardial perfusion and vulnerable atherosclerotic plaque; Medecine nucleaire et maladie coronarienne: evaluation de traceurs de la perfusion myocardique et de la plaque d'atherome vulnerable
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Broisat, A
Coronary artery disease is one of the primary cause of mortality worldwide. Nuclear medicine is the major imaging technique for diagnosis and following of this disease. perfusion: nowadays, major radioactive agents used in clinical practice are myocardial perfusion tracers. The reference tracer is thallium-201. However, {sup 201}Tl presents some drawbacks. {sup 99m}Tcn-noet has been proposed for its replacement. This study shows that in contrast with previous studies realized in vitro on cardio myocytes, verapamil, an l-type calcium channel inhibitor, does not inhibit myocardial fixation of {sup 99m}Tcn-noet in vivo in dog. This data is in agreement with the hypothesis of a non specific endothelial fixation of this tracer. Moreover, this study shows that as a pure tracer of myocardial perfusion, {sup 99m}Tcn-noet can also be used to assess myocardial viability on a model of myocardial chronic infarction in rat. atherosclerosis: disruption of vulnerable atherosclerotic plaques is the main event leading to coronary accidents. The second part of this study concerns the evaluation of new potential tracers of the vulnerable atherosclerotic plaque in an experimental model of rabbit with an inheritable hypercholesterolemia. The four tracers evaluated (b2702(r), b2702-I, b2702-Tc and Tc-raft-b2702) are synthetic peptides comprising the residues 75-84 of hla-b2702, a molecule known to link vcam-1, an adhesion molecule expressed in vulnerable atherosclerotic plaque. The autoradiography studies show that all tracers accumulate within atherosclerotic plaque expressing vcam- and that. i-b2702 shows the best plaque/control fixation ratio. (author)
Correction of lumen contrast-enhancement influence on non-calcified coronary atherosclerotic plaque quantification on CT.
Kristanto, Wisnumurti; Tuncay, Volkan; Vliegenthart, Rozemarijn; van Ooijen, Peter M A; Oudkerk, Matthijs
Lumen contrast-enhancement influences non-calcified atherosclerotic plaque Hounsfield-unit (HU) values in computed tomography (CT). This study aimed to construct and validate an algorithm to correct for this influence. Three coronary vessel phantoms with 1, 2, and 4 mm circular hollow lumina; with normal and plaque-infested walls were scanned simultaneously in oil using a dual-source CT scanner. Scanning was repeated as the lumina were alternately filled with water and four contrast solutions (100-400 HU, at 100 HU intervals). Images were reconstructed at 0.4 mm x-y pixel size. Pixel-by-pixel comparisons of contrast-enhanced and non-contrast-enhanced images confirmed exponential declining patterns in lumen contrast-enhancement influence on wall HU-values from the lumen border (y = Ae(-λx) + c). The median difference of the inside and outside 2-pixel radius part of the contrast-enhanced coronary phantom wall to the reference (non-contrast-enhanced images) was 45 and 2 HU, respectively. Based on the lumen contrast-enhancement influence patterns, a generalized correction algorithm was formulated. Application of the generalized correction algorithm to the inside 2-pixel radius part of the wall reduced the median difference to the reference to 4 HU. In conclusion, lumen contrast-enhancement influence on the vessel wall can be defined by an exponential approximation, allowing correction of the CT density of the vessel wall closest to the lumen. With this correction, a more accurate determination of vessel wall composition can be made. PMID:25326412
Bacteria and bacterial DNA in atherosclerotic plaque and aneurysmal wall biopsies from patients with and without periodontitis
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Zahra Armingohar
Full Text Available Background: Several studies have reported an association between chronic periodontitis (CP and cardiovascular diseases. Detection of periodontopathogens, including red complex bacteria (RCB, in vascular lesions has suggested these bacteria to be involved in the pathogenesis of atherosclerosis and abdominal aortic aneurysms. Objective: In this study, we investigate bacteria and their DNA in vascular biopsies from patients with vascular diseases (VD; i.e. abdominal aortic aneurysms, atherosclerotic carotid, and common femoral arteries, with and without CP. Methods: DNA was extracted from vascular biopsies selected from 40 VD patients: 30 with CP and 10 without CP. The V3-V5 region of the 16S rDNA (V3-V5 was polymerase chain reaction (PCR-amplified, and the amplicons were cloned into Escherichia coli, sequenced, and classified (GenBank and the Human Oral Microbiome database. Species-specific primers were used for the detection of Porphyromonas gingivalis. In addition, 10 randomly selected vascular biopsies from the CP group were subjected to scanning electron microscopy (SEM for visualization of bacteria. Checkerboard DNA–DNA hybridization was performed to assess the presence of RCB in 10 randomly selected subgingival plaque samples from CP patients. Results: A higher load and mean diversity of bacteria were detected in vascular biopsies from VD patients with CP compared to those without CP. Enterobacteriaceae were frequently detected in vascular biopsies together with cultivable, commensal oral, and not-yet-cultured bacterial species. While 70% of the subgingival plaque samples from CP patients showed presence of RCB, only P. gingivalis was detected in one vascular biopsy. Bacterial cells were seen in all 10 vascular biopsies examined by SEM. Conclusions: A higher bacterial load and more diverse colonization were detected in VD lesions of CP patients as compared to patients without CP. This indicated that a multitude of bacterial species both
Vascular endothelial growth factor (VEGF and monocyte chemoattractant protein (MCP-1 levels unaltered in symptomatic atherosclerotic carotid plaque patients from North India
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Dheeraj eKhurana
Full Text Available We aimed to identify the role of vascular endothelial growth factor(VEGF and monocyte chemoattractant protein(MCP-1 as a serum biomarker of symptomatic carotid atherosclerotic plaque in North Indian population. Individuals with symptomatic carotid atherosclerotic plaque have high risk of ischemic stroke. Previous studies from western countries have shown an association between VEGF and MCP-1 levels and the incidence of ischemic stroke. In this study, venous blood from 110 human subjects was collected, 57 blood samples of which were obtained from patients with carotid plaques, 38 neurological controls without carotid plaques and another 15 healthy controls who had no history of serious illness. Serum VEGF and MCP-1 levels were measured using commercially available enzyme-linked immunosorbent assay(ELISA. We also correlated the data clinically and carried out risk factor analysis based on the detailed questionnaire obtained from each patient. For risk factor analysis, a total of 70 symptomatic carotid plaque cases and equal number of age and sex matched healthy controls were analyzed. We found that serum VEGF levels in carotid plaque patients did not show any significant change when compared to either of the controls. Similarly, there was no significant upregulation of monocyte chemoattractant protein-1 in the serum of these patients. The risk factor analysis revealed that hypertension, diabetes, and physical inactivity were the main correlates of carotid atherosclerosis(p<0.05. Prevalence of patients was higher residing in urban areas as compared to rural region. We also found that patients coming from mountaineer region were relatively less vulnerable to cerebral atherosclerosis as compared to the ones residing at plain region. We conclude that the pathogenesis of carotid plaques may progress independent of these inflammatory molecules. In parallel, risk factor analysis indicates hypertension, diabetes and sedentary lifestyle as the most
Virtual histology study of atherosclerotic plaque composition in patients with stable angina and acute phase of acute coronary syndromes without ST segment elevation
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Ivanović Miloš
Full Text Available Introduction. Rupture of vulnerable atherosclerotic plaques is the cause of most acute coronary syndromes (ACS. Postmortem studies which compared stable coronary lesions and atherosclerotic plaques in patients who have died because of ACS indicated high lipid-core content as one of the major determinants of plaque vulnerability. Objective. Our primary goal was to assess the potential relations of plaque composition determined by IVUS-VH (Intravascular Ultrasound - Virtual Histology in patients with stable angina and subjects in acute phase of ACS without ST segment elevation. Methods. The study comprised of 40 patients who underwent preintervention IVUS examination. Tissue maps were reconstructed from radio frequency data using IVUS-VH software. Results. We analyzed 53 lesions in 40 patients. Stable angina was diagnosed in 24 patients (29 lesions, while acute phase of ACS without ST elevation was diagnosed in 16 patients (24 lesions. In the patients in acute phase of ACS without ST segment elevation IVUS-VH examination showed a significantly larger area of the necrotic core at the site of minimal lumen area and a larger mean of the necrotic core volume in the entire lesion comparing to stable angina subjects (1.84±0.90 mm2 vs. 0.96±0.69 mm2; p<0.001 and 20.94±15.79 mm3 vs. 11.54±14.15 mm3; p<0.05 respectively. Conclusion. IVUS-VH detected that the necrotic core was significantly larger in atherosclerotic lesions in patients in acute phase of ACS without ST elevation comparing to the stable angina subjects and that it could be considered as a marker of plaque vulnerability.
Assessment of atherosclerotic plaque inflammation can be improved by delayed time point FDG PET CT imaging
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Blomberg, Björn; Thomassen, Anders; Hildebrandt, Malene;
contrast between plaque activity and blood pool activity over time. Global aortic uptake of 18-FDG was quantified by subtracting the blood pool SUVmean from aortic SUVmax (cSUV). The change in aortic TBR and cSUV over time was determined by a Student's paired t-test. Regression coefficients summarized the...... data. Results: At 90 minutes, the aortic TBR was 2.072 ± 0.599. At 180 minutes, the aortic TBR significantly increased to 3.488 ± 1.138 (P = <0.0001). At 90 minutes, the aortic cSUV was 1.122 ± 0.505. A significant relationship was observed between aortic cSUV, aging (β = 0.019; t = 2.79; df = 12; P...... = 0.016) and gender (β = 0.502; t = 2.30; df = 12; P = 0.040). At 180 minutes, the aortic cSUV significantly increased to 1.524 ± 0.577 (P = <0.0001). This resulted in a more significant relationship between aortic cSUV, aging (β = 0.025; t = 3.44; df = 12; P = 0.005) and gender (β = 0.542; t = 2...
The effect of interleukin and matrix metalloproteinase on the vulnerability of carotid atherosclerotic plaque and cerebral infarction
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HUANG Yan
Full Text Available Objective To investigate the relationship of IL-17, IL-10 and MMP-12 with the vulnerability of carotid atherosclerotic plaque and cerebral infarction. Methods According to clinical stroke event 70 carotid atherosclersis patients were divided into asymptomatic carotid atherosclerosis (ACAS group (n = 35 and acute atherosclerotic cerebral infarction (AACI group (n = 35. The patients were also divided into vulnerable plague (VP group (n = 38 and unvulnerable plague (UVP group (n = 32 by color ultrasonic technique. Normal control group (n = 35 was established. The plasma levels of cytokines were tested by enzyme-linked immunosorbent assay (ELISA. Results Compared with the control group, the concentrations of IL-17, IL-10 and MMP-12 in ACAS group and AACI group were significantly elevated (P = 0.000; P = 0.000, moreover, the concentrations of IL-17 and MMP-12 in AACI group were higher than those in ACAS group (P = 0.000; P = 0.002, respectively. In AACI group, the level of IL-10 was lower than the ACAS group and control group (P = 0.000, for all, whereas, no significant difference of IL-10 level was seen between ACAS group and control group (P = 0.275. In VP group, the concentrations of IL-17 and MMP-12 were higher than those in UVP group (P = 0.000 and 0.014, respectively. In VP group, the level of IL-10 was lower than that in UVP group and control group (P = 0.000, for all, but no significant difference of IL-10 level was seen between UVP group and control group (P = 0.742. Correlation analysis showed, the level of IL-17 was positively correlated with the level of MMP-12 (r = 0.640, P = 0.000, and was negatively correlated with the level of IL-10 (r =-0.430, P = 0.000. The level of MMP-12 was weakly negatively correlated with the level of IL-10 (r =-0.242, P = 0.013. Conclusion IL-17, IL-10 and MMP-12 all participate the pathological process of atherosclerosis and cerebral infarction. The elevated IL-17 and MMP-12 levels and decreased IL-10 level
Imaging with radiolabelled anti-membrane type 1 matrix metalloproteinase (MT1-MMP) antibody: potentials for characterizing atherosclerotic plaques
International Nuclear Information System (INIS)
Membrane type 1 matrix metalloproteinase (MT1-MMP) activates pro-MMP-2 and pro-MMP-13 to their active forms and plays important roles in the destabilization of atherosclerotic plaques. This study sought to determine the usefulness of 99mTc-labelled monoclonal antibody (mAb), recognizing MT1-MMP, for imaging atherosclerosis in a rabbit model (WHHLMI rabbits). Anti-MT1-MMP monoclonal IgG3 and negative control IgG3 were radiolabelled with 99mTc after derivatization with 6-hydrazinonicotinic acid (HYNIC) to yield 99mTc-MT1-MMP mAb and 99mTc-IgG3, respectively. WHHLMI and control rabbits were injected with these radio-probes. The aorta was removed and radioactivity was measured at 24 h after the injection. Autoradiography and histological studies were performed. 99mTc-MT1-MMP mAb accumulation in WHHLMI rabbit aortas was 5.4-fold higher than that of control rabbits. Regional 99mTc-MT1-MMP mAb accumulation was positively correlated with MT1-MMP expression (r = 0.59, p 99mTc-IgG3 accumulation was independent of MT1-MMP expression (r = 0.03, p = NS). The highest 99mTc-MT1-MMP mAb accumulation was found in atheromatous lesions (4.8 ± 1.9, %ID x BW/mm2 x 102), followed in decreasing order by fibroatheromatous (1.8 ± 1.3), collagen-rich (1.6 ± 1.0) and neointimal lesions (1.5 ± 1.5). In contrast, 99mTc-IgG3 accumulation was almost independent of the histological grade of lesions. Higher 99mTc-MT1-MMP mAb accumulation in grade IV atheroma was shown in comparison with neointimal lesions or other more stable lesions. Nuclear imaging with 99mTc-MT1-MMP mAb, in combination with CT and MRI, could provide new diagnostic imaging capabilities for detecting vulnerable plaques, although further investigations to improve target to blood ratios are strongly required. (orig.)
Interobserver agreement for the detection of atherosclerotic plaque in coronary CT angiography: comparison of two low-dose image acquisition protocols with standard retrospectively ECG-gated reconstruction
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Schuhbaeck, Annika; Rixe, Johannes; Hamm, Christian [University of Giessen, Department of Cardiology, Giessen (Germany); Marwan, Mohamed; Gauss, Soeren; Muschiol, Gerd; Ropers, Dieter; Daniel, Werner G.; Achenbach, Stephan [University of Erlangen, Department of Cardiology, Erlangen (Germany); Schneider, Christian [University of Giessen, Department of Radiology, Giessen (Germany); Lell, Michael [University of Erlangen, Department of Radiology, Erlangen (Germany)
We compared the interobserver variability concerning the detection of calcified and non-calcified plaque in two different low-dose and standard retrospectively gated protocols for coronary CTA. 150 patients with low heart rates and less than 100 kg body weight were randomised and examined by contrast-enhanced dual-source CT coronary angiography (100 kV, 320 mAs). 50 patients were examined with prospectively ECG-triggered axial acquisition, 50 patients with prospectively ECG-triggered high pitch spiral acquisition, and 50 patients using spiral acquisition with retrospective ECG gating. Two investigators independently analysed the datasets concerning the presence of calcified and non-calcified plaque on a per-segment level. Mean effective dose was 1.4 {+-} 0.2 mSv for axial, 0.8 {+-} 0.07 mSv for high-pitch spiral, and 5.3 {+-} 2.6 mSV for standard spiral acquisition (P < 0.0001). In axial acquisition, interobserver agreement concerning the presence of atherosclerotic plaque was achieved in 650/749 coronary segments (86.8%). In high-pitch spiral acquisition, agreement was achieved in 664/748 segments (88.8%, n.s.). In standard spiral acquisition, agreement was achieved in 672/738 segments (91.0%, P < 0.0001). Interobserver agreement was significantly higher for calcified than for non-calcified plaque in all data acquisition modes. Low-dose coronary CT angiography permits the detection of coronary atherosclerotic plaque with good interobserver agreement. (orig.)
Evaluation by multislice computed tomography of atherosclerotic coronary artery plaques in non-culprit, remote coronary arteries of patients with acute coronary syndrome
International Nuclear Information System (INIS)
Patients with acute coronary syndrome (ACS) frequently have vulnerable plaques in the remote coronary arteries, suggesting that ACS is part of the pan-coronary process. In the present study the computed tomography (CT) plaque density in non-culprit atherosclerotic coronary artery lesions was evaluated by multi-slice computed tomography (MSCT) in patients with ACS and non-ACS. MSCT was performed in 21 patients with ACS and 53 patients with non-ACS: 16 of the 21 ACS patients (76%) and 30 of the non-ACS 53 patients (57%) had non-calcified plaques in the non-culprit coronary arteries (p=0.18). CT-low-density plaques (CT density <68 Hounsfield units (HU)) were more frequent in the ACS group (13/16 patients, 81%) than in the non-ACS group (13/30 patients, 43%, p=0.03). In addition, the CT density of the non-culprit lesion was significantly lower in patients with ACS than in those with non-ACS (44.1±22.9 and 77.3±33.7 HU, respectively). Patients with ACS more frequently had CT-low-density plaques in the non-culprit, remote arteries than those with non-ACS, which suggests that ACS treatment should focus not only on stabilizing the culprit lesion but also on systemic stabilization of non-culprit lesions. (author)
The influence of constitutive law choice used to characterise atherosclerotic tissue material properties on computing stress values in human carotid plaques.
Teng, Zhongzhao; Yuan, Jianmin; Feng, Jiaxuan; Zhang, Yongxue; Brown, Adam J; Wang, Shuo; Lu, Qingsheng; Gillard, Jonathan H
Calculating high stress concentration within carotid atherosclerotic plaques has been shown to be complementary to anatomical features in assessing vulnerability. Reliability of stress calculation may depend on the constitutive laws/strain energy density functions (SEDFs) used to characterize tissue material properties. Different SEDFs, including neo-Hookean, one-/two-term Ogden, Yeoh, 5-parameter Mooney-Rivlin, Demiray and modified Mooney-Rivlin, have been used to describe atherosclerotic tissue behavior. However, the capacity of SEDFs to fit experimental data and the difference in the stress calculation remains unexplored. In this study, seven SEDFs were used to fit the stress-stretch data points of media, fibrous cap, lipid and intraplaque hemorrhage/thrombus obtained from 21 human carotid plaques. Semi-analytic solution, 2D structure-only and 3D fully coupled fluid-structure interaction (FSI) analyses were used to quantify stress using different SEDFs and the related material stability examined. Results show that, except for neo-Hookean, all other six SEDFs fitted the experimental points well, with vessel stress distribution in the circumferential and radial directions being similar. 2D structural-only analysis was successful for all seven SEDFs, but 3D FSI were only possible with neo-Hookean, Demiray and modified Mooney-Rivlin models. Stresses calculated using Demiray and modified Mooney-Rivlin models were nearly identical. Further analyses indicated that the energy contours of one-/two-term Ogden and 5-parameter Mooney-Rivlin models were not strictly convex and the material stability indictors under homogeneous deformations were not always positive. In conclusion, considering the capacity in characterizing material properties and stabilities, Demiray and modified Mooney-Rivlin SEDF appear practical choices for mechanical analyses to predict the critical mechanical conditions within carotid atherosclerotic plaques. PMID:26472305
Imaging of atherosclerotic aorta of rabbit model by detection of plaque inflammation with fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography
Institute of Scientific and Technical Information of China (English)
ZHAO Quan-ming; FENG Ting-ting; ZHAO Xin; XU Zhan-min; LIU Yu; LI De-peng; LI Li-qin; SU Gong; ZHANG Xiao-xia
Background Atherosclerotic plaque rupture is the primary mechanism of thrombosis which plays a key role in the onset of acute coronary syndromes. Detection of these plaques prone to rupture (vulnerable plaque) could be clinically significant for prevention of cardiac events. It has been shown that high metabolism cells have a high uptake of fluorine-18 fluorodeoxyglucose (18F-FDG). The objective of this study was to investigate the correlation of FDG uptake and the immuno-histochemistry parameters of plaques, and the effect of atorvastatin on vulnerable atherosclerotic plaque in a rabbit model.Methods Ten male New Zealand White rabbits were divided into three groups as follows: (1) normal control group (n=2,C group): the animals were fed a standard diet at 120 g/d and were given water ad labium; (2) atherosclerosis group (n=4,As group): animals were fed with high fat diet for 5 months after aortic endothelia damage; (3) treatment group (atherosclerosis + atorvastatin, n=4, Statin group): animals were fed with high fat diet for 5 months and then changed into normal chow plus atorvastatin (2.5 mg·d-1·kg-1) treatment for another 4 months. Then these four rabbits were imaged with fluorine-18 fluorodexyglucose positron emission tomography/computed tomography (PET/CT) and sacrificed for pathohistologic studies. FDG uptake by the aorta was expressed as target-to-background ratio (TBR). Maximal standardized uptake value (SUV) was measured over the thoracic and abdominal aortas. The aortic smooth muscle cell (SMC) number, CD-14 antibody positive cell (macrophage) number and the ratio of the thickness of fibrous cap to the thickness of lipid core (cap-to-core ratio) in atherosclerotic plaques were analyzed.Results As group showed significantly higher uptake of FDG than C group (SUVs: 0.746±0.172 vs. 0.286±0.073, P <0.001). After 4 months of atorvastatin treatment and the modification of diet, SUVs decreased significantly (Statin group:0.550±0.134, compared to As group
Increased expression of fatty acid binding protein 4 and leptin in resident macrophages characterises atherosclerotic plaque rupture
Lee, K.; Santibanez-Koref, M; Polvikoski, T; BIRCHALL, D; Mendelow, A D; Keavney, B.
Objective Resident macrophages play an important role in atheromatous plaque rupture. The macrophage gene expression signature associated with plaque rupture is incompletely defined due to the complex cellular heterogeneity in the plaque. We aimed to characterise differential gene expression in resident plaque macrophages from ruptured and stable human atheromatous lesions. Methods and results We performed genome-wide expression analyses of isolated macrophage-rich regions of stable and ruptu...
Imaging of inflamed carotid artery atherosclerotic plaques with the use of {sup 99m}Tc-HYNIC-IL-2 scintigraphy in end-stage renal disease patients
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Opalinska, Marta; Pach, Dorota; Sowa-Staszczak, Anna; Glowa, Boguslaw; Hubalewska-Dydejczyk, Alicja [Jagiellonian University Medical School, Nuclear Medicine Unit, Department of Endocrinology, Cracow (Poland); Stompor, Tomasz [University of Warmia and Mazury in Olsztyn, Department of Nephrology, Hypertensiology and Internal Medicine, Faculty of Medicine, Olsztyn (Poland); Mikolajczak, Renata; Garnuszek, Piotr; Maurin, Michal; Karczmarczyk, Urszula [National Centre for Nuclear Research Radioisotope Centre POLATOM, Otwock (Poland); Fedak, Danuta [Jagiellonian University Medical School, Clinical Biochemistry, Cracow (Poland); Krzanowski, Marcin; Sulowicz, Wladyslaw [Jagiellonian University Medical School, Department of Nephrology, Cracow (Poland); Rakowski, Tomasz [Jagiellonian University Medical School, 2nd Department of Cardiology, Institute of Cardiology, Cracow (Poland)
Identification of vulnerable plaques remains crucial for better cardiovascular risk assessment. At least 20% of inflammatory cells within unstable (vulnerable) plaques comprise T lymphocytes, which contain receptors for interleukin-2 (IL-2); those receptors can be identified by scintigraphy with radiolabelled IL-2.The aim of this study was to identify the ''inflamed'' (vulnerable) plaques by scintigraphy using IL-2 labelled with {sup 99m}Tc in the selected, high cardiovascular risk group of end-stage renal disease (ESRD) patients. A total of 28 patients (18 men, 10 women, aged 55.2 {+-} 9.6 years, 17 on peritoneal dialysis, 11 on haemodialysis) underwent common carotid artery (CCA) scintigraphy with the use of {sup 99m}Tc-hydrazinonicotinamide (HYNIC)-IL-2. In all cases, ultrasound examination of the CCA was performed and levels of selected proinflammatory factors, atherogenic markers and calcium-phosphate balance parameters were measured. Finally, the target to non-target (T/nT) ratio of IL-2 uptake in atherosclerotic plaques with intima-media thickness (IMT), classic cardiovascular risk factors and concentrations of the measured factors were compared. Increased {sup 99m}Tc-HYNIC-IL-2 uptake in atherosclerotic plaques in 38/41 (91%) cases was detected. The median T/nT ratio of focal {sup 99m}Tc-HYNIC-IL-2 uptake in atherosclerotic plaques was 2.35 (range 1.23-3.63). The mean IMT value on the side of plaques assessed by scintigraphy was 0.79 {+-} 0.18 mm (median 0.8, range 0.5-1.275). Correlations between T/nT ratio and homocysteine (R = 0.22, p = 0.037), apolipoprotein B (apoB) (R = 0.31, p = 0.008), apoB to apoA-I ratio (R = 0.29, p = 0.012) and triglyceride concentration (R = 0.26, p = 0.021) were detected. A lower T/nT ratio in patients with better parameters of nutritional status (haemoglobin, albumin, adiponectin) in comparison with patients with worse nutritional parameters (3.20 {+-} 0.5 vs 2.16 {+-} 0.68, p = 0.025) was revealed as well
Advantage in Bright-blood and Black-blood Magnetic Resonance Imaging with High-resolution for Analysis of Carotid Atherosclerotic Plaques
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Mei Li
Full Text Available Background: About 50% of the cerebral ischemia events are induced by intracranial and extracranial atherosclerosis. This study aimed to evaluate the feasibility and accuracy for displaying atherosclerotic plaques in carotid arteries and analyzing their ingredients by using high-resolution new magnetic resonance imaging (MRI techniques. Methods: Totally, 49 patients suspected of extracranial carotid artery stenosis were subjected to cranial MRI scan and magnetic resonance angiography (MRA examination on carotid arteries, and high-resolution bright-blood and black-blood MRI analysis was carried out within 1 week. Digital subtraction angiography (DSA examination was carried out for 16 patients within 1 month. Results: Totally, 103 plaques were detected in the 49 patients, which were characterized by localized or diffusive thickening of the vessel wall, with the intrusion of crescent-shaped abnormal signal into lumens. Fibrous cap was displayed as isointensity in T1-weighted image (T1WI and hyperintensities in proton density weighted image (PDWI and T2-weighted image (T2WI, lipid core was displayed as isointensity or slight hyperintensities in T1WI, isointensity, hyperintensities or hypointensity in PDWI, and hypointensity in T2WI. Calcification in plaques was detected in 11 patients. Eight patients were detected with irregular plaque surface or ulcerative plaques, which were characterized by irregular intravascular space surface in the black-blood sequences, black hypointensity band was not detected in three-dimensional time-of-flight, or the hypointensity band was not continuous, and intrusion of hyperintensities into plaques can be detected. Bright-blood and black-blood techniques were highly correlated with the diagnosis of contrast-enhanced MRA in angiostenosis degree, Rs = 0.97, P < 0.001. In comparison to DSA, the sensitivity, specificity, and accuracy of MRI diagnosis of stenosis for ≥50% were 88.9%, 100%, and 97.9%, respectively
The Arginine/ADMA Ratio Is Related to the Prevention of Atherosclerotic Plaques in Hypercholesterolemic Rabbits When Giving a Combined Therapy with Atorvastatine and Arginine
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Saskia J. H. Brinkmann
Full Text Available Supplementation with arginine in combination with atorvastatin is more efficient in reducing the size of an atherosclerotic plaque than treatment with a statin or arginine alone in homozygous Watanabe heritable hyperlipidemic (WHHL rabbits. We evaluated the mechanism behind this feature by exploring the role of the arginine/asymmetric dimethylarginine (ADMA ratio, which is the substrate and inhibitor of nitric oxide synthase (NOS and thereby nitric oxide (NO, respectively. Methods: Rabbits were fed either an arginine diet (group A, n = 9, standard rabbit chow plus atorvastatin (group S, n = 8, standard rabbit chow plus an arginine diet with atorvastatin (group SA, n = 8 or standard rabbit chow (group C, n = 9 as control. Blood was sampled and the aorta was harvested for topographic and histological analysis. Plasma levels of arginine, ADMA, cholesterol and nitric oxide were determined and the arginine/ADMA ratio was calculated. Results: The decrease in ADMA levels over time was significantly correlated to fewer aortic lesions in the distal aorta and total aorta. The arginine/ADMA ratio was correlated to cholesterol levels and decrease in cholesterol levels over time in the SA group. A lower arginine/ADMA ratio was significantly correlated to lower NO levels in the S and C group. Discussion: A balance between arginine and ADMA is an important indicator in the prevention of the development of atherosclerotic plaques.
Distribution of ultrasonic radiofrequency signal amplitude detects lipids in atherosclerotic plaque of coronary arteries: an ex-vivo study
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Moroi Masao
Full Text Available Abstract Background Accumulation of lipids within coronary plaques is an important process in disease progression. However, gray-scale intravascular ultrasound images cannot detect plaque lipids effectively. Radiofrequency signal analysis could provide more accurate information on preclinical coronary plaques. Methods We analyzed 29 zones of mild atheroma in human coronary arteries acquired at autopsy. Two histologic groups, i.e., plaques with a lipid core (group L and plaques without a lipid core (group N, were analyzed by automatic calculation of integrated backscatter. One hundred regions of interest were set on the target zone. Radiofrequency signals from a 50 MHz transducer were digitized at 240 MHz with 12-bit resolution. The intensity of integrated backscatter and its distribution within each plaque were compared between the two groups. Results Although the mean backscatter was similar between the groups, intraplaque variation of backscatter and backscatter in the axial direction were larger in group L than in group N (p = 0.02. Conventional intravascular ultrasound showed extremely low sensitivity for lipid detection, despite a high specificity. In contrast, a cut-off value>32 for the total variance of integrated backscatter identified lipid-containing plaque with a high sensitivity (85% and specificity (75%. Conclusion Compared with conventional imaging, assessment of the intraplaque distribution of integrated backscatter is more effective for detecting lipid. As coronary atheroma progresses, its composition becomes heterogeneous and multi-layered. This radiofrequency technique can portray complex plaque histology and can detect the early stage of plaque progression.
Pregnancy associated plasma protein-A (PAPP-A) is not a marker of the vulnerable atherosclerotic plaque
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Iversen, Kasper; Teisner, Ane; Dalager, Soren;
To investigate if pregnancy associated plasma protein-A (PAPP-A) was present in the vulnerable plaque, and if not, to find alternative hypothesis for the release of PAPP-A.......To investigate if pregnancy associated plasma protein-A (PAPP-A) was present in the vulnerable plaque, and if not, to find alternative hypothesis for the release of PAPP-A....
Pregnancy associated plasma protein-A (PAPP-A) is not a marker of the vulnerable atherosclerotic plaque
DEFF Research Database (Denmark)
Iversen, Kasper K; Teisner, Ane Søgaard; Dalager, Soren;
OBJECTIVE: To investigate if pregnancy associated plasma protein-A (PAPP-A) was present in the vulnerable plaque, and if not, to find alternative hypothesis for the release of PAPP-A. DESIGN AND METHODS: Vulnerable plaques and control tissues were examined by immunohistochemistry. Volunteers and...
TU-F-12A-06: BEST IN PHYSICS (IMAGING) - A Novel Catheter-Based Radionuclide Imaging System to Characterize Atherosclerotic Plaque
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Zaman, R; Kosuge, H; Carpenter, C; Pratx, G; Sun, C; McConnell, M; Xing, L [Stanford University School of Medicine, Stanford, CA (United States)
Purpose: Atherosclerosis underlies coronary artery diseases, the leading cause of death in the United States and worldwide. In this study, we developed a novel catheter-based radionuclide imaging (CRI) system to image 18F-fluorodeoxyglucose (18F-FDG), a radionuclide, a marker of vascular inflammation, in murine carotid arteries and characterized the system for spatial resolution from multiple scintillating materials. Methods: The catheter system includes 35 mm and 8 mm fixed focal length lenses, which are subsequently connected to a CMOS camera and fiber holder. The distal ferrule of an image bundle is terminated with a wide-angle lens. The novelty of this system is a scintillating balloon with a crystal tip in the front of the wide angle lens to image light from the decay of 18F-FDG emission signal. The scintillating balloon is fabricated from 1mL of silicone RTV catalyst mixed with 1 mL base and 50 mg/mL calcium fluoride doped with Europium (CaF2:Eu). To identify the optimal scintillating materials with respect to resolution, we calculated modulation transfer function (MTF) of Yttrium Aluminum Garnet doped with Cerium (YAG:Ce), anthracene, and CaF2:Eu phosphors using a thin line optical phantom (Fig. 1a-1b). Macrophage-rich FVB murine atherosclerotic carotid plaque model (n = 4) was used in ex vivo experiments. Confirmatory imaging was also performed by an external optical imaging system (IVIS-200). Results: Analysis of the different phosphors (Fig 1b) showed that CaF2:Eu enabled the best resolution of 1.2μm. The CRI system visualized 18F-FDG in atherosclerotic plaques (Fig. 1d). The ligated left carotid (LR) artery exhibited 4× higher 18F-FDG signal intensity compared to the non-ligated right carotid (negative control) artery (1.65×10{sup 2} ±4.07×10{sup 1} vs. 4.44×10{sup 1}±2.17×10{sup 0}, A.U., p = 0.005) and confirmed with IVIS-200 (Fig. 1d). Conclusion: This CRI system enables high-resolution and sensitive detection of 18F-FDG uptake by murine
Ultrasound and Biochemical Diagnostic Tools for the Characterization of Vulnerable Carotid Atherosclerotic Plaque.
Lechareas, Simeon; Yanni, Amalia E; Golemati, Spyretta; Chatziioannou, Achilles; Perrea, Despoina
Stroke is a leading cause of morbidity and mortality worldwide, and characterization of vulnerable carotid plaque remains the spearhead of scientific research. Plaque destabilization, the key factor that induces the series of events leading to the clinical symptoms of carotid artery disease, is a consequence of complex mechanical, structural and biochemical processes. Novel imaging and molecular markers have been studied as predictors of disease outcome with promising results. The aim of this review is to present the current state of research on the association between ultrasound-derived echogenicity indices and blood parameters indicative of carotid plaque stability and activity. Bibliographic research revealed that there are limited available data. Among the biomarkers studied, those related to oxidative stress, lipoproteins and diabetes/insulin resistance are associated with echolucent plaques, whereas adipokines are associated with echogenic plaques. Biomarkers of inflammation and coagulation have not exhibited any conclusive relationship with plaque echogenicity, and it is not possible to come to any conclusion regarding calcification-, apoptosis- and neo-angiogenesis-related parameters because of the extremely limited bibliographic data. PMID:26493239
{sup 99m}Tc-interleukin-2 scintigraphy for the in vivo imaging of vulnerable atherosclerotic plaques
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Annovazzi, Alessio; D' Alessandria, Calogero; Scopinaro, Francesco [University La Sapienza, Nuclear Medicine, 2nd Faculty of Medicine, Rome (Italy); Bonanno, Elena; Spagnoli, Luigi G. [University Tor Vergata, Department of Biopathology and Diagnostic Imaging, Rome (Italy); Arca, Marcello [University La Sapienza, Department of Clinical and Applied Medical Therapy, 1st Faculty of Medicine, Rome (Italy); Marcoccia, Antonella; Violi, Francesco [University La Sapienza, Medical Clinical Institute 1, 1st Faculty of Medicine, Rome (Italy); Toma, Giorgio De [University La Sapienza, Department of Surgery Pietro Valdoni, 1st Faculty of Medicine, Rome (Italy); Signore, Alberto [University La Sapienza, Nuclear Medicine, 2nd Faculty of Medicine, Rome (Italy); University of Groningen, Department of Nuclear Medicine, Groningen (Netherlands); Ospedale S. Andrea, Nuclear Medicine, Roma (Italy)
Several histopathological studies have demonstrated that vulnerable plaques are enriched in inflammatory cells. The aims of this study were: (1a) to test the ability of {sup 99m}Tc-labelled interleukin-2 ({sup 99m}Tc-IL2) to bind to IL2R-positive (IL2R+) cells in carotid plaques and (1b) to correlate the plaque uptake of {sup 99m}Tc-IL2, measured in vivo, with the number of IL2R+ cells within the plaque, measured ex vivo by histology (transversal study, TS), and (2) to evaluate changes in {sup 99m}Tc-IL2 uptake in plaques, before and after treatment with a statin or a hypocholesterolaemic diet (longitudinal study, LS). Ultrasound scan was performed for plaque characterisation and localisation. Fourteen patients (16 plaques) eligible for endoarterectomy were recruited for the TS and underwent {sup 99m}Tc-IL2 scintigraphy before surgery. Nine patients (13 plaques) were recruited for the LS; these patients received atorvastatin or a standard hypocholesterolaemic diet and {sup 99m}Tc-IL2 scintigraphy was performed before and after 3 months of treatment. The degree of {sup 99m}Tc-IL2 uptake was expressed as the plaque/background (T/B) ratio. In patients from TS, T/B ratios correlated with the percentage of IL2R+ cells at histology (r=0.707; p=0.002) and the number of IL2R+ cells at flow cytometry (r=0.711; p=0.006). No correlations were observed between ultrasound scores and either scintigraphic or histological findings. In patients from the LS, the mean {sup 99m}Tc-IL2 uptake decreased in statin-treated patients (1.75{+-}0.50 vs 2.16{+-}0.44; p=0.012), while it was unchanged in the patients on the hypocholesterolaemic diet (2.33{+-}0.45 vs 2.34{+-}0.5). {sup 99m}Tc-IL2 accumulates in vulnerable carotid plaques; this accumulation is correlated with the amount of IL2R+ cells and is influenced by lipid-lowering treatment with a statin. (orig.)
Distribution of selected elements in atherosclerotic plaques of apoE/LDLR-double knockout mice subjected to dietary and pharmacological treatments
International Nuclear Information System (INIS)
Gene-targeted, apolipoprotein E and LDL receptor-double knockout (apoE/LDLR-/-) mice represent a new animal model that displays severe hyperlipidemia and atherosclerosis. The aim of the present study was to show changes in histomorphology and in distribution of selected elements in atherosclerotic plaques of apoE/LDLR-/- mice fed egg-rich proatherosclerotic diet (5% egg-yolk lyophilisate) supplemented or not with perindopril (inhibitor of angiotensin converting enzyme; 2 mg/kg b.w.). Synchrotron radiation micro-X-ray fluorescence spectrometry was combined with histological stainings to determine distribution and concentration of trace and essential elements in atherosclerotic lesions. More advanced atherosclerotic lesions expressed by total area occupied by lipids (oil red-O staining) and by macrophages (CD68 immunohistochemistry) were observed in animals fed egg-rich diet. The perindopril treatment attenuated these effects. No significant differences were observed in the number of intimal smooth muscle cells (smooth muscle actin immunohistochemistry). In animals fed egg-rich diet significantly higher concentrations of Ca and significantly lower contents of S, Cl, , Fe, Cu, Zn and Se in atheromas were seen in comparison to chow diet-fed animals. After pharmacological treatment, concentrations of S, Cl, Fe, Cu, Zn and Se showed the tendency to achieve levels like in animals fed normal diet. K level differed only in group treated with perindopril. Concentration of P did not significantly vary in all experimental groups. Perindopril showed its potency to reduce atherosclerosis, as estimated by the size of the atheroma and content of pro- and antiatherogenic elements.
Distribution of selected elements in atherosclerotic plaques of apoE/LDLR-double knockout mice subjected to dietary and pharmacological treatments
Gajda, Mariusz; Kowalska, Joanna; Banaś, Agnieszka; Banaś, Krzysztof; Kwiatek, Wojciech M.; Kostogrys, Renata B.; Mateuszuk, łukasz; ChŁopicki, Stefan; Litwin, Jan A.; Appel, Karen
Gene-targeted, apolipoprotein E and LDL receptor-double knockout (apoE/LDLR -/-) mice represent a new animal model that displays severe hyperlipidemia and atherosclerosis. The aim of the present study was to show changes in histomorphology and in distribution of selected elements in atherosclerotic plaques of apoE/LDLR -/- mice fed egg-rich proatherosclerotic diet (5% egg-yolk lyophilisate) supplemented or not with perindopril (inhibitor of angiotensin converting enzyme; 2 mg/kg b.w.). Synchrotron radiation micro-X-ray fluorescence spectrometry was combined with histological stainings to determine distribution and concentration of trace and essential elements in atherosclerotic lesions. More advanced atherosclerotic lesions expressed by total area occupied by lipids (oil red-O staining) and by macrophages (CD68 immunohistochemistry) were observed in animals fed egg-rich diet. The perindopril treatment attenuated these effects. No significant differences were observed in the number of intimal smooth muscle cells (smooth muscle actin immunohistochemistry). In animals fed egg-rich diet significantly higher concentrations of Ca and significantly lower contents of S, Cl, , Fe, Cu, Zn and Se in atheromas were seen in comparison to chow diet-fed animals. After pharmacological treatment, concentrations of S, Cl, Fe, Cu, Zn and Se showed the tendency to achieve levels like in animals fed normal diet. K level differed only in group treated with perindopril. Concentration of P did not significantly vary in all experimental groups. Perindopril showed its potency to reduce atherosclerosis, as estimated by the size of the atheroma and content of pro- and antiatherogenic elements.
Distribution of selected elements in atherosclerotic plaques of apoE/LDLR-double knockout mice subjected to dietary and pharmacological treatments
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Gajda, Mariusz, E-mail: email@example.com [Department of Histology, Jagiellonian University Medical College, Kopernika 7, 31-034 Krakow (Poland); Kowalska, Joanna [Institute of Nuclear Physics, Radzikowskiego 152, 31-342 Krakow (Poland); Banas, Agnieszka; Banas, Krzysztof [Singapore Synchrotron Light Source, National University of Singapore, 5 Research Link, 117603 Singapore (Singapore); Kwiatek, Wojciech M. [Institute of Nuclear Physics, Radzikowskiego 152, 31-342 Krakow (Poland); Kostogrys, Renata B. [Department of Human Nutrition, Agricultural University of Krakow, Balicka 122, 30-149, Krakow (Poland); Mateuszuk, Lukasz; ChLopicki, Stefan [Department of Experimental Pharmacology, Jagiellonian University Medical College, Kopernika 7, 31-531 Krakow (Poland); Litwin, Jan A. [Department of Histology, Jagiellonian University Medical College, Kopernika 7, 31-034 Krakow (Poland); Appel, Karen [Hasylab, DESY, Notkestrasse 85, D-22607, Hamburg (Germany)
Gene-targeted, apolipoprotein E and LDL receptor-double knockout (apoE/LDLR{sup -/-}) mice represent a new animal model that displays severe hyperlipidemia and atherosclerosis. The aim of the present study was to show changes in histomorphology and in distribution of selected elements in atherosclerotic plaques of apoE/LDLR{sup -/-} mice fed egg-rich proatherosclerotic diet (5% egg-yolk lyophilisate) supplemented or not with perindopril (inhibitor of angiotensin converting enzyme; 2 mg/kg b.w.). Synchrotron radiation micro-X-ray fluorescence spectrometry was combined with histological stainings to determine distribution and concentration of trace and essential elements in atherosclerotic lesions. More advanced atherosclerotic lesions expressed by total area occupied by lipids (oil red-O staining) and by macrophages (CD68 immunohistochemistry) were observed in animals fed egg-rich diet. The perindopril treatment attenuated these effects. No significant differences were observed in the number of intimal smooth muscle cells (smooth muscle actin immunohistochemistry). In animals fed egg-rich diet significantly higher concentrations of Ca and significantly lower contents of S, Cl, , Fe, Cu, Zn and Se in atheromas were seen in comparison to chow diet-fed animals. After pharmacological treatment, concentrations of S, Cl, Fe, Cu, Zn and Se showed the tendency to achieve levels like in animals fed normal diet. K level differed only in group treated with perindopril. Concentration of P did not significantly vary in all experimental groups. Perindopril showed its potency to reduce atherosclerosis, as estimated by the size of the atheroma and content of pro- and antiatherogenic elements.
Lumen segmentation and motion estimation in B-mode and contrast-enhanced ultrasound images of the carotid artery in patients with atherosclerotic plaque.
Carvalho, Diego D B; Akkus, Zeynettin; van den Oord, Stijn C H; Schinkel, Arend F L; van der Steen, Antonius F W; Niessen, Wiro J; Bosch, Johan G; Klein, Stefan
In standard B-mode ultrasound (BMUS), segmentation of the lumen of atherosclerotic carotid arteries and studying the lumen geometry over time are difficult owing to irregular lumen shapes, noise, artifacts, and echolucent plaques. Contrast enhanced ultrasound (CEUS) improves lumen visualization, but lumen segmentation remains challenging owing to varying intensities, CEUS-specific artifacts and lack of tissue visualization. To overcome these challenges, we propose a novel method using simultaneously acquired BMUS&CEUS image sequences. Initially, the method estimates nonrigid motion (NME) from the image sequences, using intensity-based image registration. The motion-compensated image sequence is then averaged to obtain a single "epitome" image with improved signal-to-noise ratio. The lumen is segmented from the epitome image through an intensity joint-histogram classification and a graph-based segmentation. NME was validated by comparing displacements with manual annotations in 11 carotids. The average root mean square error (RMSE) was 112±73 μm . Segmentation results were validated against manual delineations in the epitome images of two different datasets, respectively containing 11 (RMSE 191±43 μm) and 10 (RMSE 351±176 μm ) carotids. From the deformation fields, we derived arterial distensibility with values comparable to the literature. The average errors in all experiments were in the inter-observer variability range. To the best of our knowledge, this is the first study exploiting combined BMUS&CEUS images for atherosclerotic carotid lumen segmentation. PMID:25423650
Grating-based X-ray phase-contrast tomography of atherosclerotic plaque at high photon energies
International Nuclear Information System (INIS)
Background: Tissue characterization of atherosclerosis by absorption-based imaging methods is limited due to low soft-tissue contrast. Grating-based phase-contrast computed tomography (PC-CT) may become an alternative for plaque assessment if the phase signal can be retrieved at clinically applicable photon energies. The aims of this feasibility study were (i) to characterize arterial vessels at low and high photon energies, (ii) to extract qualitative features and (iii) quantitative phase-contrast Hounsfield units (HU-phase) of plaque components at 53 keV using histopathology as gold standard. Materials and methods: Five human carotid artery specimens underwent grating-based PC-CT using synchrotron radiation of either 23 keV or 53 keV and histological work-up. Specimens without advanced atherosclerosis were used to extract signal criteria of vessel layers. Diseased specimens were screened for important plaque components including fibrous tissue (FT), lipid (LIP), necrotic core (NEC), intraplaque hemorrhage (IPH), inflammatory cell infiltration (INF) and calcifications (CA). Qualitative features as well as quantitative HU-phase were analyzed. Results: Thirty-three regions in 6 corresponding PC-CT scans and histology sections were identified. Healthy samples had the same signal characteristics at 23 keV and 53 keV with bright tunica intima and adventitia and dark media. Plaque components showed differences in signal intensity and texture at 53 keV. Quantitative analysis demonstrated the highest HU-phase of soft plaque in dense FT. Less organized LIP, NEC and INF were associated with lower HU-phase values. The highest HU-phase were measured in CA. Conclusion: PC-CT of atherosclerosis is feasible at high, clinically relevant photon energies and provides detailed information about plaque structure including features of high risk vulnerable plaques. (orig.)
The effect of lipid regulation with atorvastatin on the blood lipid levels and carotid artery plaques in patients with atherosclerotic cerebral infarction
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Shu XU
Full Text Available Objective To analyze the effect of intensive lipid regulation treatment with atorvastatin on the blood lipid levels and carotid artery plaques in patients with atherosclerotic cerebral infarction. Methods Ninety-two patients with atherosclerotic cerebral infarction were randomly divided into two groups: observation group (treated by atorvastatin calcium with the dosage of 20 mg/d, N = 46 and control group (treated by diet without lipid-rich food, N=46. Besides, other drugs given to the patients in two groups were the same. The blood lipid levels and the changes of carotid artery plaques in two groups were analyzed and compared before treatment and 3 months after treatment. Results After treatment, the concentrations of total cholesterol [TC, (4.23 ± 0.92 mmol/L vs (5.24 ± 0.68 mmol/L], triglyceride [TG, (2.46 ± 0.28 mmol/L vs (3.33 ± 0.47 mmol/L], low-density lipoprotein cholesterol [LDL-C, (2.52 ± 0.38 mmol/L vs (4.78 ± 0.86 mmol/L] in the patients of observation group were all decreased and significantly lower than those in the control group (P = 0.000, for all, and the concentration of high-density lipoprotein cholesterol [HDL-C, (1.13 ± 0.41 mmol/L vs (0.85 ± 0.32 mmol/L] in the patients of observation group was increased and significantly than that in the control group (P = 0.003. The carotid artery plaque size [(20.25 ± 0.32 mm2 vs (24.42 ± 10.33 mm2] and thickness [(0.59 ± 0.13 mm vs (1.93 ± 0.23 mm] of carotid artery plaques and intima?media thickness [IMT, (1.32 ± 0.67 mm vs (1.63 ± 0.56 mm] of common carotid artery (CCA in the patients of observation group were all significantly lower than those in patients in the control group (P = 0.000, 0.000, 0.010, respectively. Comparing serum alanine aminotransferase (ALT, aspartate aminotransferase (AST, creatine kinase (CK and creatinine (Cr levels after treatment with before treatment, there was no significant difference between 2 groups (P > 0.05, for all. Conclusions
Assessment of atherosclerotic plaque collagen content and architecture using polarization-sensitive optical coherence tomography (Conference Presentation)
Doradla, Pallavi; Villiger, Martin; Tshikudi, Diane M.; Bouma, Brett E.; Nadkarni, Seemantini K.
Acute myocardial infarction, caused by the rupture of vulnerable coronary plaques, is the leading cause of death worldwide. Collagen is the primary extracellular matrix macromolecule that imparts the mechanical stability to a plaque and its reduction causes plaque instability. Intracoronary polarization sensitive optical coherence tomography (PS-OCT) measures the polarization states of the backscattered light from the tissue to evaluate plaque birefringence, a material property that is elevated in proteins such as collagen with an ordered structure. Here we investigate the dependence of the PS-OCT parameters on the quantity of the plaque collagen and fiber architecture. In this study, coronary arterial segments from human cadaveric hearts were evaluated with intracoronary PS-OCT and compared with Histopathological assessment of collagen content and architecture from picrosirius-red (PSR) stained sections. PSR sections were visualized with circularly-polarized light microscopy to quantify collagen birefringence, and the additional assessment of color hue indicated fibril thickness. Due to the ordered architecture of thick collagen fibers, a positive correlation between PS-OCT retardation and quantity of thick collagen fibers (r=0.54, p=0.04), and similarly with the total collagen content (r=0.51, p=0.03) was observed. In contrast, there was no perceivable relationship between PS-OCT retardation and the presence of thin collagen fibers (r=0.08, p=0.07), suggesting that thin and disorganized collagen fiber architecture did not significantly contribute to the PS-OCT retardation. Further analysis will be performed to assess the relationship between PS-OCT retardation and collagen architecture based on immunohistochemical analysis of collagen type. These results suggest that intracoronary PS-OCT may open the opportunity to assess collagen architecture in addition total collagen content, potentially enabling an improved understanding of coronary plaque rupture.
HMGB1 is associated with atherosclerotic plaque composition and burden in patients with stable coronary artery disease.
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Martin Andrassy
Full Text Available OBJECTIVES: The role of inflammation in atherosclerosis is widely appreciated. High mobility group box 1 (HMGB1, an injury-associated molecular pattern molecule acting as a mediator of inflammation, has recently been implicated in the development of atherosclerosis. In this study, we sought to investigate the association of plasma HMGB1 with coronary plaque composition in patients with suspected or known coronary artery disease (CAD. DESIGN: HMGB1, high sensitive troponin T (hsTnT and high sensitive C-reactive protein (hsCRP were determined in 152 consecutive patients with suspected or known stable CAD who underwent clinically indicated 256-slice coronary computed tomography angiography (CCTA. Using CCTA, we assessed 1 coronary calcification, 2 non-calcified plaque burden and 3 the presence of vascular remodeling in areas of non-calcified plaques. RESULTS: Using univariate analysis, hsCRP, hsTnT and HMGB1 as well as age, and atherogenic risk factors were associated with non-calcified plaque burden (r = 0.21, p = 0.009; r = 0.48, p<0.001 and r = 0.34, p<0.001, respectively. By multivariate analysis, hsTnT and HMGB1 remained independent predictors of the non-calcified plaque burden (r = 0.48, p<0.01 and r = 0.34, p<0.001, respectively, whereas a non-significant trend was noticed for hs-CRP (r = 0.21, p = 0.07. By combining hsTnT and HMGB1, a high positive predictive value for the presence of non-calcified and remodeled plaque (96% and 77%, respectively was noted in patients within the upper tertiles for both biomarkers, which surpassed the positive predictive value of each marker separately. CONCLUSIONS: In addition to hs-TnT, a well-established cardiovascular risk marker, HMGB1 is independently associated with non-calcified plaque burden in patients with stable CAD, while the predictive value of hs-CRP is lower. Complementary value was observed for hs-TnT and HMGB1 for the prediction of complex coronary plaque.
Quantitative analysis of ultrasound B-mode images of carotid atherosclerotic plaque: correlation with visual classification and histological examination
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Wilhjelm, Jens E.; Grønholdt, Marie-Louise; Wiebe, Brit;
regions of the plaque in still ultrasound images from three orthogonal scan planes and finally a histological analysis of the surgically removed plaque. The quantitative comparison was made with the linear model and with separation of the available data into training and test sets. The comparison of...... subjective classification with features from still ultrasound images revealed an overall agreement of 60 % for classification of echogenicity and 70 % for classification of structure. Comparison of the histologically determined relative volume of soft materials with features from the still images revealed a...... soft materials for individual patients. Reasons for this is discussed in the paper, together with suggestions for improvements....
Clinical Study on Effect of Garlicin in Stabilizing the Carotid Artery Atherosclerotic Plaque in Patients with Primary Hypertension and Coronary Artery Disease
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CHENG Wen-li; KE Yuan-nan; SHI Zai-xiang; WANG Ying; CHEN Li; JU Gao; FAN Shu-ying
Objective: To investigate the effect of garlicin in treating carotid artery atherosclerotic plaque (CAAP) in patients with primary hypertension and coronary heart disease (PHT-CHD). Methods: Seventynine patients with PHT-CHD were randomly divided into the treated group (39 patients) treated with garlicin and fosinopril and the control group (40 patients) treated with fosinopril alone. The change of CAAP was evaluated by high frequency ultrasonic examination every six months, and the changes of intercellular adhesion molecule-1 (ICAM-1) and high sensitive C-reactive protein (hs-CRP) were measured by ELISA, with the observation proceeding for 52 weeks totally. Results: By the end of the experiment, the number of complex plaques, Crouse integrals, intima-media thickness, serum ICAM-1 and hs-CRP were significantly lower in the treated group than those in the control group with significant difference (P<0.05). Conclusion; Garlicin could stabilize CAAP to a certain extent and shows a definite vascular protective effect in patients with PHT-CHD.
Detection of vulnerable atherosclerotic plaque and prediction of thrombosis events in a rabbit model using 18F-FDG -PET/CT.
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Quan-ming Zhao
Full Text Available BACKGROUND: Detection of vulnerable plaques could be clinically significant in the prevention of cardiovascular events. We aimed to compare Fluorine-18 fluorodeoxyglucose ((18F-FDG uptake in vulnerable and stable plaques, and investigate the feasibility of predicting thrombosis events using Positron Emission Tomography/Computed Tomography (PET/CT angiography. METHODS: Atherosclerosis was induced in 23 male New Zealand white rabbits. The rabbits underwent pharmacological triggering to induce thrombosis. A pre-triggered PET/CTA scan and a post-triggered PET/CTA scan were respectively performed. (18F-FDG uptake by the aorta was expressed as maximal standardized uptake value (SUVmax and mean SUV (SUVmean. SUVs were measured on serial 7.5 mm arterial segments. RESULTS: Thrombosis was identified in 15 of 23 rabbits. The pre-triggered SUVmean and SUVmax were 0.768 ± 0.111 and 0.804 ± 0.120, respectively, in the arterial segments with stable plaque, and 1.097 ± 0.189 and 1.229 ± 0.290, respectively, in the arterial segments with vulnerable plaque (P<0.001, respectively. The post-triggered SUVmean and SUVmax were 0.849 ± 0.167 and 0.906 ± 0.191, respectively in the arterial segments without thrombosis, and 1.152 ± 0.258 and 1.294 ± 0.313, respectively in the arterial segments with thrombosis (P<0.001, respectively. The values of SUVmean in the pre-triggered arterial segments were used to plot a receiver operating characteristic curve (ROC for predicting thrombosis events. Area under the curve (AUC was 0.898. Maximal sensitivity and specificity (75.4% and 88.5%, respectively were obtained when SUVmean was 0.882. CONCLUSIONS: Vulnerable and stable plaques can be distinguished by quantitative analysis of (18F-FDG uptake in the arterial segments in this rabbit model. PET/CT may be used for predicting thrombosis events and risk-stratification in patients with atherosclerotic disease.
The role of contrast-enhanced ultrasound (CEUS) in visualizing atherosclerotic carotid plaque vulnerability: Which injection protocol? Which scanning technique?
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Iezzi, Roberto, E-mail: firstname.lastname@example.com [Department of Bioimaging and Radiological Sciences, Institute of Radiology, "A. Gemelli" Hospital—Catholic University, L.go A Gemelli 8, 00168 Rome (Italy); Petrone, Gianluigi [Institute of Pathology, "A. Gemelli" Hospital—Catholic University, L.go A Gemelli 8, 00168, Rome (Italy); Ferrante, Angela [Department of Vascular Surgery, "A. Gemelli" Hospital—Catholic University, L.go A Gemelli 8, 00168 Rome (Italy); Lauriola, Libero [Institute of Pathology, "A. Gemelli" Hospital—Catholic University, L.go A Gemelli 8, 00168, Rome (Italy); Vincenzoni, Claudio [Department of Vascular Surgery, "A. Gemelli" Hospital—Catholic University, L.go A Gemelli 8, 00168 Rome (Italy); Torre, Michele Fabio la [Department of Bioimaging and Radiological Sciences, Institute of Radiology, "A. Gemelli" Hospital—Catholic University, L.go A Gemelli 8, 00168 Rome (Italy); Snider, Francesco [Department of Vascular Surgery, "A. Gemelli" Hospital—Catholic University, L.go A Gemelli 8, 00168 Rome (Italy); Rindi, Guido [Institute of Pathology, "A. Gemelli" Hospital—Catholic University, L.go A Gemelli 8, 00168, Rome (Italy); Bonomo, Lorenzo [Department of Bioimaging and Radiological Sciences, Institute of Radiology, "A. Gemelli" Hospital—Catholic University, L.go A Gemelli 8, 00168 Rome (Italy)
Highlights: • CEUS is a safe and efficacious technique for the identification and characterization of carotid plaque. • CEUS represents a diagnostic tool for the management of patients with carotid plaque, particularly in asymptomatic patients. • Improved diagnostic performance is achieved with the injection of 4 mL bolus of contrast-medium. • Improved diagnostic performance is achieved with the use of Dynamic Imaging rather than late-phase imaging. - Abstract: Purpose: To correlate the degree of plaque vulnerability as determined by contrast-enhanced ultrasound (CEUS) with histological findings. Secondary objectives were to optimize the CEUS acquisition technique and image evaluation methods. Materials and methods: Fifty consecutive patients, either symptomatic and asymptomatic referring to our department in order to perform carotid endarterectomy (TEA), were enrolled. Each patient provided informed consent before undergoing CEUS. Ultrasound examination was performed using high-frequency (8–14 MHz) linear probe and a non-linear pulse inversion technique (mechanical index: 0.09–1.3). A double contrast media injection (Sonovue, 2 mL and 4 mL; Bracco, Italy) was performed. Two videotapes were recorded for every injection: early "dynamic" phase and late "flash" phase, performed with 6 high mechanical index impulses. Movies were quantitatively and qualitatively evaluated. Qualitative and quantitative evaluation were statistically compared to immunohistological diagnosis of vulnerable plaque, considered as gold standard. Results: Qualitative CEUS evaluation obtained high statistical results when compared to immunohistological results, with values of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of 94%, 68%, 87%, 85% and 86%, respectively, which became higher if considering only asymptomatic patient, with a NPV of 91%. Nevertheless, quantitative software evaluation proved less
The role of contrast-enhanced ultrasound (CEUS) in visualizing atherosclerotic carotid plaque vulnerability: Which injection protocol? Which scanning technique?
International Nuclear Information System (INIS)
Highlights: • CEUS is a safe and efficacious technique for the identification and characterization of carotid plaque. • CEUS represents a diagnostic tool for the management of patients with carotid plaque, particularly in asymptomatic patients. • Improved diagnostic performance is achieved with the injection of 4 mL bolus of contrast-medium. • Improved diagnostic performance is achieved with the use of Dynamic Imaging rather than late-phase imaging. - Abstract: Purpose: To correlate the degree of plaque vulnerability as determined by contrast-enhanced ultrasound (CEUS) with histological findings. Secondary objectives were to optimize the CEUS acquisition technique and image evaluation methods. Materials and methods: Fifty consecutive patients, either symptomatic and asymptomatic referring to our department in order to perform carotid endarterectomy (TEA), were enrolled. Each patient provided informed consent before undergoing CEUS. Ultrasound examination was performed using high-frequency (8–14 MHz) linear probe and a non-linear pulse inversion technique (mechanical index: 0.09–1.3). A double contrast media injection (Sonovue, 2 mL and 4 mL; Bracco, Italy) was performed. Two videotapes were recorded for every injection: early "dynamic" phase and late "flash" phase, performed with 6 high mechanical index impulses. Movies were quantitatively and qualitatively evaluated. Qualitative and quantitative evaluation were statistically compared to immunohistological diagnosis of vulnerable plaque, considered as gold standard. Results: Qualitative CEUS evaluation obtained high statistical results when compared to immunohistological results, with values of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of 94%, 68%, 87%, 85% and 86%, respectively, which became higher if considering only asymptomatic patient, with a NPV of 91%. Nevertheless, quantitative software evaluation proved less
Defining the non-vulnerable and vulnerable patients with computed tomography coronary angiography: evaluation of atherosclerotic plaque burden and composition.
Rodriguez-Granillo, Gaston A; Carrascosa, Patricia; Bruining, Nico; Waksman, Ron; Garcia-Garcia, Hector M
The shift from coronary plaque stability to plaque instability remains poorly understood despite enormous efforts and expenditures have been assigned to the study of the subject. On the other hand, there have been serious advances in imaging helping us to characterizenon-vulnerable patients The latter has much more value in the clinical decision-making process since it provides high certainty that the patient's probability of a future acute event is low and treatment decisions should be made accordingly. Although coronary plaque rupture is still recognized as the main source of acute thrombotic events, numerous studies have shown that the prediction of events on an individual basis is far more complex and demands a more open approach aimed at characterizing patient risk rather than assessing the risk of thrombosis of a single plaque. Computed tomography coronary angiography (CTCA) has the ability to evaluate non-invasively the extent, burden, severity, and characteristics of coronary artery disease (CAD) and has a close relationship to intravascular ultrasound. On the basis of an excellent negative predictive value with an annualized event rate of ∼0.20% assessed over more than 6000 patients, thus providing a 5-year warranty period, CTCA has been identified as the finest non-invasive tool to exclude CAD. This means that CTCA is able to reliably characterize the non-vulnerable patient. Conversely, in the past few years, several studies have attempted to establish CTCA-derived predictors of acute coronary syndromes, both from a lesion level and a patient level basis with very low positive predictive value, thus questioning the vulnerable patient/plaque concept. PMID:26903599
Selective ablation of rabbit atherosclerotic plaque with less thermal effect by the control of pulse structure of a quantum cascade laser in the 5.7 μm wavelength range
Hashimura, Keisuke; Ishii, Katsunori; Awazu, Kunio
Cholesteryl esters are main components of atherosclerotic plaques and have an absorption peak at the wavelength of 5.75 μm originated from C=O stretching vibration mode of ester bond. Our group achieved the selective ablation of atherosclerotic lesions using a quantum cascade laser (QCL) in the 5.7 μm wavelength range. QCLs are relatively new types of semiconductor lasers that can emit mid-infrared range. They are sufficiently compact and considered to be useful for clinical application. However, large thermal effects were observed because the QCL worked as quasicontinuous wave (CW) lasers due to its short pulse interval. Then we tried macro pulse irradiation (irradiation of pulses at intervals) of the QCL and achieved effective ablation with less-thermal effects than conventional quasi-CW irradiation. However, lesion selectivity might be changed by changing pulse structure. Therefore, in this study, irradiation effects of the macro pulse irradiation to rabbit atherosclerotic plaque and normal vessel were compared. The macro pulse width and the macro pulse interval were set to 0.5 and 12 ms, respectively, because the thermal relaxation time of rabbit normal and atherosclerotic aortas in the oscillation wavelength of the QCL was 0.5-12 ms. As a result, cutting difference was achieved between rabbit atherosclerotic and normal aortas by the macro pulse irradiation. Therefore, macro pulse irradiation of a QCL in the 5.7 μm wavelength range is effective for reducing thermal effects and selective ablation of the atherosclerotic plaque. QCLs have the potential of realizing less-invasive laser angioplasty.
Enhancement of plaque formation and cell fusion of an enteropathogenic coronavirus by trypsin treatment.
Storz, J.; Rott, R; Kaluza, G.
Plaque formation, replication, and related cytopathic functions of the enteropathogenic bovine coronavirus strain L9 in bovine fetal thyroid (BFTy) and bovine fetal brain (BFB) cells were investigated in the presence and absence of trypsin. Plaque formation was enhanced in both cell types. Plaques reached a size with an average diameter of 5 mm within 4 days with trypsin in the overlay, whereas their diameter remained less than 1 mm at this time after plating without trypsin in the overlay. F...
Atherosclerotic Plaque Inflammation Varies Between Vascular Sites and Correlates With Response to Inhibition of Lipoprotein‐Associated Phospholipase A2
Fenning, Robert S.; Burgert, Mark E.; Hamamdzic, Damir; Peyster, Eliot G.; Mohler, Emile R; Kangovi, Shreya; Jucker, Beat M.; Lenhard, Stephen C.; Macphee, Colin H.; Wilensky, Robert L.
Background Despite systemic exposure to risk factors, the circulatory system develops varying patterns of atherosclerosis for unclear reasons. In a porcine model, we investigated the relationship between site‐specific lesion development and inflammatory pathways involved in the coronary arteries (CORs) and distal abdominal aortas (AAs). Methods and Results Diabetes mellitus (DM) and hypercholesterolemia (HC) were induced in 37 pigs with 3 healthy controls. Site‐specific plaque development was...
Cholesterol-independent effects of atorvastatin prevent cardiovascular morbidity and mortality in a mouse model of atherosclerotic plaque rupture.
Roth, Lynn; Rombouts, Miche; Schrijvers, Dorien M; Martinet, Wim; De Meyer, Guido R Y
Because cholesterol-independent effects of statins are difficult to determine in patients, we studied these pleiotropic effects in apolipoprotein E-deficient (ApoE(-/-)) mice with a mutation in the fibrillin-1 gene (Fbn1(C1039G+/-)). These mice develop exacerbated atherosclerosis and spontaneous plaque ruptures, accompanied by myocardial infarctions (MI) and sudden death. ApoE(-/-)Fbn1(C1039G+/-) mice were fed a Western diet (WD). At week 10 of WD, mice were divided in a control (WD), atorvastatin (10mg/kg/day + WD) and cholesterol withdrawal group (cholW, normal chow). The latter was included to compare the effects of atorvastatin with dietary lipid lowering. Fifteen weeks later, the mice were sacrificed. CholW, but not atorvastatin, reduced plasma cholesterol. Survival increased from 50% to 90% both in cholW and atorvastatin treated mice. CholW as well as atorvastatin treatment increased plaque collagen and fibrous cap thickness, but they did not affect the amount of plaque macrophages and T cells. MMP-2 and MMP-9 activity was significantly lower and the expression of MMP-12, TNF-α and IL-1β was strongly reduced in both treatment groups. Blood monocytes and neutrophils returned to baseline levels (ApoE(-/-) mice before the onset of atherosclerosis). Importantly, atorvastatin but not cholW significantly reduced coronary stenosis (from 50 to 28%) and the occurrence of MI (from 43 to 10%). In conclusion, independent of cholesterol lowering, atorvastatin significantly reduced mortality, plaque vulnerability and inflammation to the same extent as cholW. In addition, atorvastatin but not cholW reduced coronary stenosis and the occurrence of MI. These data unequivocally illustrate the significance of the pleiotropic effects of atorvastatin in the prevention of cardiovascular morbidity and mortality. PMID:26826559
64Cu-DOTATATE PET/MRI for detection of activated macrophages in carotid atherosclerotic plaques
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Pedersen, Sune Folke; Sandholt, Benjamin Vikjær; Keller, Sune Høgild;
selected markers of plaque vulnerability using real-time quantitative polymerase chain reaction. These results were compared with in vivo 64Cu-DOTATATE uptake calculated as the mean standardized uptake value. Univariate analysis of real-time quantitative polymerase chain reaction and PET showed that...... cluster of differentiation 163 (CD163) and CD68 gene expression correlated significantly but weakly with mean standardized uptake value in scans performed 85 minutes post injection (P<0.001 and P=0.015, respectively). Subsequent multivariate analysis showed that CD163 correlated independently with 64Cu...
Maintenance of Macrophage Redox Status by ChREBP Limits Inflammation and Apoptosis and Protects against Advanced Atherosclerotic Lesion Formation
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Vincent Sarrazy
Full Text Available Enhanced glucose utilization can be visualized in atherosclerotic lesions and may reflect a high glycolytic rate in lesional macrophages, but its causative role in plaque progression remains unclear. We observe that the activity of the carbohydrate-responsive element binding protein ChREBP is rapidly downregulated upon TLR4 activation in macrophages. ChREBP inactivation refocuses cellular metabolism to a high redox state favoring enhanced inflammatory responses after TLR4 activation and increased cell death after TLR4 activation or oxidized LDL loading. Targeted deletion of ChREBP in bone marrow cells resulted in accelerated atherosclerosis progression in Ldlr−/− mice with increased monocytosis, lesional macrophage accumulation, and plaque necrosis. Thus, ChREBP-dependent macrophage metabolic reprogramming hinders plaque progression and establishes a causative role for leukocyte glucose metabolism in atherosclerosis.
Disturbed flow mediated modulation of shear forces on endothelial plane: A proposed model for studying endothelium around atherosclerotic plaques
Balaguru, Uma Maheswari; Sundaresan, Lakshmikirupa; Manivannan, Jeganathan; Majunathan, Reji; Mani, Krishnapriya; Swaminathan, Akila; Venkatesan, Saravanakumar; Kasiviswanathan, Dharanibalan; Chatterjee, Suvro
Disturbed fluid flow or modulated shear stress is associated with vascular conditions such as atherosclerosis, thrombosis, and aneurysm. In vitro simulation of the fluid flow around the plaque micro-environment remains a challenging approach. Currently available models have limitations such as complications in protocols, high cost, incompetence of co-culture and not being suitable for massive expression studies. Hence, the present study aimed to develop a simple, versatile model based on Computational Fluid Dynamics (CFD) simulation. Current observations of CFD have shown the regions of modulated shear stress by the disturbed fluid flow. To execute and validate the model in real sense, cell morphology, cytoskeletal arrangement, cell death, reactive oxygen species (ROS) profile, nitric oxide production and disturbed flow markers under the above condition were assessed. Endothelium at disturbed flow region which had been exposed to low shear stress and swirling flow pattern showed morphological and expression similarities with the pathological disturbed flow environment reported previously. Altogether, the proposed model can serve as a platform to simulate the real time micro-environment of disturbed flow associated with eccentric plaque shapes and the possibilities of studying its downstream events.
Plaque of atherosclerosis in aorta: review on atherogenesis, formation of plaque, clinical significance, methods of imaging and treatment
International Nuclear Information System (INIS)
There is a certain consensus in the literature that the earliest stage of atherogenesis is characterized by the accumulation of spongy cells in the region of the intimal artery. Risk factors such as arterial hypertension, smoking, diabetes mellitus, hypercholesterolemia, male gender and advanced age predispose a person to the formation of plaques in the coronaries and aorta. A greater number of acute coronary events as well as strokes have been observed in people with these risk factors. Strokes are the third cause of death in the USA, with about 40% of the cases being of cryptogenic origin. Since 1989 the atheroma plaques which develop in the thoracic aorta have been considered to be responsible for cerebral and peripheral strokes which were previously considered cryptogenic because imaging techniques such as electrocardiogram transesophageal, computerized tomogram, nuclear magnetic angio-resonance have visualized and characterized the lesions with plaques of arteriosclerosis in the thoracic aorta. The authors of this article made a systematic review in the PUBMED about arteriosclerosis in the aorta and its diagnostic methods. This review includes the physiopathology of the formation of atheroma to the aorta and its consequences, diagnostic methods such as echo transesophageal, computerized tomogram and angio resonance, as well as the advantages and disadvantages of each method of identification of the lesions. An analysis of the clinical significance of the size, form and location of the atheroma plaques in the thoracic aorta were made based on clinical studies, as well as their treatment with anticoagulants, antiplatelet and drugs to reduce cholesterol. (author)
A direct vulnerable atherosclerotic plaque elasticity reconstruction method based on an original material-finite element formulation: theoretical framework
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The peak cap stress (PCS) amplitude is recognized as a biomechanical predictor of vulnerable plaque (VP) rupture. However, quantifying PCS in vivo remains a challenge since the stress depends on the plaque mechanical properties. In response, an iterative material finite element (FE) elasticity reconstruction method using strain measurements has been implemented for the solution of these inverse problems. Although this approach could resolve the mechanical characterization of VPs, it suffers from major limitations since (i) it is not adapted to characterize VPs exhibiting high material discontinuities between inclusions, and (ii) does not permit real time elasticity reconstruction for clinical use. The present theoretical study was therefore designed to develop a direct material-FE algorithm for elasticity reconstruction problems which accounts for material heterogeneities. We originally modified and adapted the extended FE method (Xfem), used mainly in crack analysis, to model material heterogeneities. This new algorithm was successfully applied to six coronary lesions of patients imaged in vivo with intravascular ultrasound. The results demonstrated that the mean relative absolute errors of the reconstructed Young's moduli obtained for the arterial wall, fibrosis, necrotic core, and calcified regions of the VPs decreased from 95.3±15.56%, 98.85±72.42%, 103.29±111.86% and 95.3±10.49%, respectively, to values smaller than 2.6 × 10−8±5.7 × 10−8% (i.e. close to the exact solutions) when including modified-Xfem method into our direct elasticity reconstruction method. (paper)
Modulating the Gut Microbiota Improves Glucose Tolerance, Lipoprotein Profile and Atherosclerotic Plaque Development in ApoE-Deficient Mice.
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Ida Rune
Full Text Available The importance of the gut microbiota (GM in disease development has recently received increased attention, and numerous approaches have been made to better understand this important interplay. For example, metabolites derived from the GM have been shown to promote atherosclerosis, the underlying cause of cardiovascular disease (CVD, and to increase CVD risk factors. Popular interest in the role of the intestine in a variety of disease states has now resulted in a significant proportion of individuals without coeliac disease switching to gluten-free diets. The effect of gluten-free diets on atherosclerosis and cardiovascular risk factors is largely unknown. We therefore investigated the effect of a gluten-free high-fat cholesterol-rich diet, as compared to the same diet in which the gluten peptide gliadin had been added back, on atherosclerosis and several cardiovascular risk factors in apolipoprotein E-deficient (Apoe-/- mice. The gluten-free diet transiently altered GM composition in these mice, as compared to the gliadin-supplemented diet, but did not alter body weights, glucose tolerance, insulin levels, plasma lipids, or atherosclerosis. In parallel, other Apoe-/- mice fed the same diets were treated with ampicillin, a broad-spectrum antibiotic known to affect GM composition. Ampicillin-treatment had a marked and sustained effect on GM composition, as expected. Furthermore, although ampicillin-treated mice were slightly heavier than controls, ampicillin-treatment transiently improved glucose tolerance both in the absence or presence of gliadin, reduced plasma LDL and VLDL cholesterol levels, and reduced aortic atherosclerotic lesion area. These results demonstrate that a gluten-free diet does not seem to have beneficial effects on atherosclerosis or several CVD risk factors in this mouse model, but that sustained alteration of GM composition with a broad-spectrum antibiotic has beneficial effects on CVD risk factors and atherosclerosis
Anti-atherosclerotic potential of gossypetin via inhibiting LDL oxidation and foam cell formation
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Gossypetin, a flavone originally isolated from Hibiscus species, has been shown to possess antioxidant, antimicrobial, and antimutagenic activities. Here, we investigated the mechanism(s) underlying the anti-atherosclerotic potential of gossypetin. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) scavenging activity assay showed that the addition of > 50 μM of gossypetin could scavenge over 50% of DPPH radicals. The inhibitory effects of gossypetin on the lipid and protein oxidation of LDL were defined by thiobarbituric acid reactive substance (TBARS) assay, the relative electrophoretic mobility (REM) of oxidized LDL (ox-LDL), and fragmentation of apoB in the Cu2+-induced oxidation of LDL. Gossypetin showed potential in reducing ox-LDL-induced foam cell formation and intracellular lipid accumulation, and uptake ability of macrophages under non-cytotoxic concentrations. Molecular data showed that these influences of gossypetin might be mediated via peroxisome proliferator-activated receptor α (PPARα)/liver-X receptor α (LXRα)/ATP-binding cassette transporter A1 (ABCA1) and PPARγ/scavenger receptor CD36 pathways, as demonstrated by the transfection of PPARα siRNA or PPARγ expression vector. Our data implied that gossypetin regulated the PPAR signals, which in turn led to stimulation of cholesterol removal from macrophages and delay atherosclerosis. These results suggested that gossypetin potentially could be developed as an anti-atherosclerotic agent. - Highlights: • The anti-atherosclerotic effect of gossypetin in vitro was examined. • Gossypetin inhibited LDL oxidation. • Gossypetin showed potential in reducing on the formation of foam cells. • Gossypetin functions against ox-LDL through PPARa activation and PPARγ depression
Anti-atherosclerotic potential of gossypetin via inhibiting LDL oxidation and foam cell formation
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Chen, Jing-Hsien [School of Nutrition, Chung Shan Medical University, Taichung, Taiwan (China); Department of Medical Research, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Tsai, Chia-Wen [Department of Nutrition, China Medical University, Taichung, Taiwan (China); Wang, Chi-Ping [Department of Clinical Laboratory, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Lin, Hui-Hsuan, E-mail: email@example.com [Department of Medical Research, Chung Shan Medical University Hospital, Taichung, Taiwan (China); School of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan (China)
Gossypetin, a flavone originally isolated from Hibiscus species, has been shown to possess antioxidant, antimicrobial, and antimutagenic activities. Here, we investigated the mechanism(s) underlying the anti-atherosclerotic potential of gossypetin. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) scavenging activity assay showed that the addition of > 50 μM of gossypetin could scavenge over 50% of DPPH radicals. The inhibitory effects of gossypetin on the lipid and protein oxidation of LDL were defined by thiobarbituric acid reactive substance (TBARS) assay, the relative electrophoretic mobility (REM) of oxidized LDL (ox-LDL), and fragmentation of apoB in the Cu{sup 2+}-induced oxidation of LDL. Gossypetin showed potential in reducing ox-LDL-induced foam cell formation and intracellular lipid accumulation, and uptake ability of macrophages under non-cytotoxic concentrations. Molecular data showed that these influences of gossypetin might be mediated via peroxisome proliferator-activated receptor α (PPARα)/liver-X receptor α (LXRα)/ATP-binding cassette transporter A1 (ABCA1) and PPARγ/scavenger receptor CD36 pathways, as demonstrated by the transfection of PPARα siRNA or PPARγ expression vector. Our data implied that gossypetin regulated the PPAR signals, which in turn led to stimulation of cholesterol removal from macrophages and delay atherosclerosis. These results suggested that gossypetin potentially could be developed as an anti-atherosclerotic agent. - Highlights: • The anti-atherosclerotic effect of gossypetin in vitro was examined. • Gossypetin inhibited LDL oxidation. • Gossypetin showed potential in reducing on the formation of foam cells. • Gossypetin functions against ox-LDL through PPARa activation and PPARγ depression.
Oleic acid induces smooth muscle foam cell formation and enhances atherosclerotic lesion development via CD36
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Tang Bing
Full Text Available Abstract Background Elevated plasma free fatty acid (FFA levels have been linked to the development of atherosclerosis. However, how FFA causes atherosclerosis has not been determined. Because fatty acid translocase (FAT/CD36 is responsible for the uptake of FFA, we hypothesized that the atherogenic effects of FFA may be mediated via CD36. Results We tested this hypothesis using cultured rat aortic smooth muscle cells (SMCs treated with oleic acid (OA. We found that OA induces lipid accumulation in SMCs in a dose dependent manner. Rat aortic SMCs treated for 48 hours with OA (250 μmol/L became foam cells based on morphological (Oil Red O staining and biochemical (5 times increase in cellular triglyceride criteria. Moreover, specific inhibition of CD36 by sulfo-N-succinimidyl oleate significantly attenuated OA induced lipid accumulation and foam cell formation. To confirm these results in vivo, we used ApoE-deficient mice fed with normal chow (NC, OA diet, NC plus lipolysis inhibitor acipimox or OA plus acipimox. OA-fed mice showed increased plasma FFA levels and enhanced atherosclerotic lesions in the aortic sinus compared to the NC group (both p 5 μm2 vs. OA plus acipimox: 2.60 ± 0.10 ×105 μm2, p p Conclusions These findings suggest that OA induces smooth muscle foam cell formation and enhances atherosclerotic lesions in part though CD36. Furthermore, these findings provide a novel model for the investigation of atherosclerosis.
Coronary-Heart-Disease-Associated Genetic Variant at the COL4A1/COL4A2 Locus Affects COL4A1/COL4A2 Expression, Vascular Cell Survival, Atherosclerotic Plaque Stability and Risk of Myocardial Infarction.
Yang, Wei; Ng, Fu Liang; Chan, Kenneth; Pu, Xiangyuan; Poston, Robin N; Ren, Meixia; An, Weiwei; Zhang, Ruoxin; Wu, Jingchun; Yan, Shunying; Situ, Haiteng; He, Xinjie; Chen, Yequn; Tan, Xuerui; Xiao, Qingzhong; Tucker, Arthur T; Caulfield, Mark J; Ye, Shu
Genome-wide association studies have revealed an association between coronary heart disease (CHD) and genetic variation on chromosome 13q34, with the lead single nucleotide polymorphism rs4773144 residing in the COL4A2 gene in this genomic region. We investigated the functional effects of this genetic variant. Analyses of primary cultures of vascular smooth muscle cells (SMCs) and endothelial cells (ECs) from different individuals showed a difference between rs4773144 genotypes in COL4A2 and COL4A1 expression levels, being lowest in the G/G genotype, intermediate in A/G and highest in A/A. Chromatin immunoprecipitation followed by allelic imbalance assays of primary cultures of SMCs and ECs that were of the A/G genotype revealed that the G allele had lower transcriptional activity than the A allele. Electrophoretic mobility shift assays and luciferase reporter gene assays showed that a short DNA sequence encompassing the rs4773144 site interacted with a nuclear protein, with lower efficiency for the G allele, and that the G allele sequence had lower activity in driving reporter gene expression. Analyses of cultured SMCs from different individuals demonstrated that cells of the G/G genotype had higher apoptosis rates. Immunohistochemical and histological examinations of ex vivo atherosclerotic coronary arteries from different individuals disclosed that atherosclerotic plaques with the G/G genotype had lower collagen IV abundance and thinner fibrous cap, a hallmark of unstable, rupture-prone plaques. A study of a cohort of patients with angiographically documented coronary artery disease showed that patients of the G/G genotype had higher rates of myocardial infarction, a phenotype often caused by plaque rupture. These results indicate that the CHD-related genetic variant at the COL4A2 locus affects COL4A2/COL4A1 expression, SMC survival, and atherosclerotic plaque stability, providing a mechanistic explanation for the association between the genetic variant and CHD
Intraplaque hemorrhage is associated with higher structural stresses in human atherosclerotic plaques: an in vivo MRI-based 3d fluid-structure interaction study
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Canton Gador
Full Text Available Abstract Background Studies using medical images have shown that intraplaque hemorrhage may accelerate plaque progression and may produce a stimulus for atherosclerosis development by increasing lipid core and plaque volume and creating new destabilizing factors. Image-based 3D computational models with fluid-structure interactions (FSI will be used to perform plaque mechanical analysis and investigate possible associations between intraplaque hemorrhage and both plaque wall stress (PWS and flow shear stress (FSS. Methods In vivo MRI data of carotid plaques from 5 patients with intraplaque hemorrhage confirmed by histology were acquired. 3D multi-component FSI models were constructed for each plaque to obtain mechanical stresses. Plaque Wall Stress (PWS and Flow Shear Stress (FSS were extracted from all nodal points on the lumen surface of each plaque for analysis. Results The mean PWS value from all hemorrhage nodes of the 5 plaques combined was higher than that from non-hemorrhage nodes (75.6 versus 68.1 kPa, P = 0.0003. The mean PWS values from hemorrhage nodes for each of the 5 plaques were all significantly higher (5 out of 5 than those from non-hemorrhage nodes (P 2, P = 0.0002. However, the mean flow shear stress values from individual cases showed mixed results: only one out of five plaques showed mean FSS value from hemorrhage nodes was higher than that from non-hemorrhage nodes; three out of five plaques showed that their mean FSS values from hemorrhage nodes were lower than those from non-hemorrhage nodes; and one plaque showed that the difference had no statistical significance. Conclusion The results of this study suggested that intraplaque hemorrhage nodes were associated with higher plaque wall stresses. Compared to flow shear stress, plaque wall stress has a better correlation with plaque component feature (hemorrhage linked to plaque progression and vulnerability. With further validation, plaque stress analysis may provide
颈动脉粥样硬化斑块与血浆纤维蛋白原的关系%Relationship between Carotid Atherosclerotic Plaque and Plasma Fibrinogen
Institute of Scientific and Technical Information of China (English)
戴志刚; 王涛; 武文元
[ Objective ] To study the relationship between carotid atherosclerosis and plasma fibrinogen. [ Methods] Color Doppler was carried out on carotid artery of 65 carotid atherosclerotic patients, recording position, echo intensity of artherosclerotic plaque,carotid artery intima-media thickness and vessel inside diameter. According to carotid artery stenosis, the patients were divided into 4 groups, and were re-divided into 2 groups ( hard plaque and soft plaque ) on the basis of character of atherosclerotic plaque, meanwhile, detecting the level of plasma fibrinogen, and performing statistical analysis. [ Results ] With the increasing level of plasma fibrinogen , the degree of carotid atherosclerotic stenosis was increased, showing positive correlation; the rate of plasma fibrinogen soft plaque of middle and high density groups is obviously higher than the lower density group. [ Conclusion ] Plasma fibrinogen level is closely correlated with characteristic of carotid atherosclerotic plaque. Plasma fibrinogen may determine the stability of carotid atherosclerotic plaque. And the increasing level of plasma fibrinogen is closely related with carotid atherosclerosis and plays an important role in its development.%目的 探讨患者颈动脉粥样硬化程度以及颈动脉粥样硬化性质与血浆纤维蛋白原的关系.方法 对存在颈动脉粥样硬化的65例患者进行颈动脉彩色多普勒检查,记录颈动脉粥样硬化斑块的部位、回声强度、颈总动脉分叉处内膜中层厚度及血管内径,并根据颈动脉狭窄程度分为4组,再根据超声检查动脉硬化斑块性质分为硬斑和软斑2组,同时检测血浆纤维蛋白原水平,进行统计学分析.结果 随着血浆纤维蛋白原水平的升高,动脉粥样硬化狭窄程度也随之增加,且呈正相关;中、高浓度纤维蛋白原组软斑发生率明显多于低浓度组.结论 血浆纤维蛋白原水平与颈动脉粥样硬化斑块的性质有关,血浆纤维蛋�