Functional and structural alterations of large arteries: methodological issues.
Ultrasound assessment of vascular biomarkers has been implemented for screening, prevention and improvement of cardiovascular risk stratification beyond classical risk factors including smoking, diabetes, hypercholesterolemia and hypertension. Thus, the presence of vascular damage at the sub-clinical, asymptomatic stages can identify a "vulnerable" patient, and aid in implementing cardiovascular prevention strategies. Increased intima-media thickness of the common carotid artery is a well-known marker of early atherosclerosis, which significantly correlates with the development of coronary or cerebro-vascular disease. More recently, guidelines for cardiovascular prevention in hypertension also introduced other vascular parameters evaluating both mechanical and functional arterial properties of peripheral arteries. Increased arterial stiffness, which can be detected by ultrasound at the common carotid, has been shown to predict future cardiovascular events and it is already considered a subclinical target organ of hypertensive patients. Even earlier vascular abnormalities such as endothelial dysfunction in the peripheral arteries, detected as reduced flow-mediated dilation of the brachial artery by ultrasound, have also been mentioned for their possible clinical use in the future. This manuscript reviews clinical evidence supporting the use of these different vascular markers for cardiovascular risk stratification, focusing on the need for an accurate, robust and reliable methodology for the assessment of vascular markers, which could improve their predictive value and increase their use in routine clinical practice.