Is Stiffness Parameter β Useful for the Evaluation of Atherosclerosis? ∼ Its Clinical Implications, Limitations, and Future Perspectives

Atherosclerosis comprises two components, atherosis and sclerosis, characterized by morphological wall thickening and functional stiffening, respectively, of the arterial wall. In recent years, much interest has been directed to the role of functional changes in large arteries, i.e., increased stiffness or decreased elasticity, on the development of cardiovascular diseases. In fact, the clinical evaluation of arterial stiffness is increasingly performed in patients with cardiovascular risk factors. Local arterial stiffness is measured using an ultrasound technique implemented with an echo-tracking system at the common carotid and femoral arteries. Several indices of local arterial stiffness are obtained by ultrasound, among which stiffness parameter beta is unique because it is the least affected by blood pressure at the time of measurement. Evidence from cross-sectional studies indicates that increased stiffness parameter beta is associated with a number of cardiovascular risk factors, such as older age, smoking, insufficient physical activity, hypertension, obesity, metabolic syndrome, insulin resistance, type 2 diabetes, chronic kidney disease, and comorbid cardiovascular disease. Results from several prospective observational studies also suggest that carotid stiffness parameter beta is a useful surrogate marker of cardiovascular events and/or mortality, although the results differ depending on the characteristics of the study subjects. Furthermore, several interventional studies have shown that carotid stiffness parameter beta improved after lifestyle modification or drug treatment. In this review, we summarize the current evidence of stiffness parameter beta of the carotid artery and discuss its clinical implications as a marker of vascular health or as a predictor of cardiovascular outcomes.

Automated summary

Atherosclerosis consists of wall thickening and stiffening of the arterial wall, with a focus on the impact of functional changes in large arteries on cardiovascular diseases. Local arterial stiffness can be measured by ultrasound, with stiffness parameter beta showing associations with multiple cardiovascular risk factors. Research indicates that carotid stiffness parameter beta can serve as a surrogate marker for cardiovascular events and mortality.