PMC8804532_01
TTE and brain MRI. (A-C) Longitudinal TTE: (A,B) apical 4-chamber and (C) parasternal long-axis views. (A) TTE shows tiny MAC along the posterior mitral annulus 1 year ago (arrowhead). (B,C) TTE after admission shows MAC progression (arrowhead) and a large round mass superimposed on the MAC (arrow). Mass with wide attachment (10 x11 mm in size) is characterized by heterogeneity and oscillation. (C) Notably, color Doppler TTE showed no significant mitral regurgitation. (D-G) Brain diffusion-weighted MRI detects multiple acute cerebral infarctions in both hemispheres (arrowheads). LA, left atrium; LV, left ventricle; MAC, mitral annular calcification; MRI, magnetic resonance imaging; TTE, transthoracic echocardiography.
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Pelvic computed tomography revealed that the balloon of the Foley catheter was observed in the prostatic urethra, suggesting urethral injury (Supplementary Figure 1A). On day 4, follow-up laboratory test results revealed leukocytosis (16,600/muL) with further increased C-reactive protein levels of 15.9 mg/dL (Supplementary Figure 1B). Notably, an inhomogeneous mobile mass superimposed on the MAC was observed despite the absence of remarkable mitral regurgitation, suggesting vegetations (Figures 1A-C; Supplementary Videos 1, 2). Brain magnetic resonance imaging revealed multiple cerebral infarctions compatible with systemic embolism (Figures 1D-G).
TEE of the mitral valve. (A) 3D TEE or (B,C) 2D color Doppler TEE shows a long mobile mass of vegetations which consist of body part (arrow) and tail part (dotted arrow), containing calcium-dense stippling, attached to the calcified posterior mitral annulus (arrowheads). Note the intact valve leaflets. (D) 4D TEE with Flexi-slice mode demonstrates MAC with a central echolucent area (arrowheads) around the P2 segment of the mitral valve. (E) Q-analysis presents a contrast analysis that traces the grayscale intensity in a defined region of interest as a function of time: green, yellow, and red depicts the center of MAC, the periphery of MAC, and normal cardiac muscle tissue as a control, respectively (left). Time-intensity curves are plotted for the respective region of interest (right): X axis, Time (s); and Y axis, Intensity scale (logarithmic) (dB). AML, anterior mitral leaflet; Ao, aorta; LA, left atrium; LV, left ventricle; MAC, mitral annular calcification; PML, posterior mitral leaflet; TEE, transesophageal echocardiography.
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TEE further characterized the vegetations involving the MAC. 2D/3D TEE revealed a growing and prolapsing mass of vegetations originating from the MAC (Figures 2A-C; Supplementary Videos 3, 4). Notably, the MAC where vegetations were attached was located around the P2 segment of the mitral valve (MV) and contained a hypoechoic region in the center, suggesting an annular abscess (Figure 2D). In addition, Q-analysis demonstrated that the hypoechoic region showed a low-intensity signal, which was different from both adjacent calcification and normal tissue and indicates a distinct property, supporting this notion (Figure 2E).
Intraoperative and pathological findings. (A) Intraoperative view of the mitral valve. A large mass of vegetations superimposed on mitral annular calcification (arrow) is observed around the P2 segment in the posterior mitral annulus (white arrowheads). (B,C) Representative macro-photographs of the extracted mitral valve leaflets (B, PML; C, AML). (D,E) Histological findings of the resected PML shows dystrophic calcification (yellow arrowheads), and surrounding neutrophilic inflammatory cell infiltration and bacterial agglomeration (red arrowheads) [(D) hematoxylin and eosin staining, Bar 200 mum; (E), gram staining, Bar 20 mum]. AML, anterior mitral leaflet; LA, left atrium; PML, posterior mitral leaflet.
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Visual inspection of the MV revealed a large mass of vegetations superimposed on the calcified posterior annulus of the MV (Figures 3A-C). Finally, gram-positive bacterial infection was confirmed by pathological examination of the resected MV (Figures 3D,E).
Timeline of case presentation. BCs, blood cultures; CTRX, ceftriaxone; IE, infective endocarditis; MAC, mitral annular calcification; MINO, minocycline; MRI, magnetic resonance imaging; MRSA, methicillin-resistant Staphylococcus aureus; MV, mitral valve; MVR, mitral valve replacement; ST, sulfamethoxazole/trimethoprim; TEE, transesophageal echocardiography; TTE, transthoracic echocardiography; UTI, urinary tract infection; VCM, vancomycin.
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