Arterial Stiffness: Is This a Marker for the Current Status or Future?

Brachial-ankle pulse wave velocity (baPWV) can be measured using a simple and highly reproducible method; therefore, measurement of this parameter is highly feasible in clinical practice. However, the clinical significance of baPWV measurement is not yet completely established. Several cross-sectional studies have suggested that baPWV measurement may be a useful screening test for subclinical atherosclerosis. Other prospective studies have reported that baPWV is a useful predictor of future cardiovascular events. Two recent aggregate meta-analyses have confirmed that increased arterial stiffness as assessed by baPWV is an independent risk factor affecting cardiovascular prognosis 1, 2). Two plausible explanations have been proposed for the association of baPWV with cardio-vascular prognosis 3). One is that baPWV reflects the atherosclerotic burden, including the formation of focal plaque lesions in the systemic arterial tree, and is therefore an acceptable marker to predict future car-diovascular events. This is also the reason why baPWV measurement has been suggested as a screening test for subclinical atherosclerosis. Another explanation is as follows: The conduit arteries are highly elastic. This elasticity has beneficial effects on the cardiovascular system, such as facilitating organ blood supply during diastole, particularly to the heart, reducing the cardiac afterload, and/or protecting the arterial wall and micro-vasculature from the mechanical stresses generated by cardiac contractions. Impaired arterial elasticity, i.e., increased arterial stiffness, causes increased cardiac afterload, impaired coronary blood supply, microvas-cular damage in the brain and kidney, and atherogen-esis. Some studies have reported the existence of a significant association of baPWV with coronary calcifica-tion/coronary atherosclerosis as assessed by coronary computed tomography or with carotid atherosclerosis as assessed by carotid ultrasound 4-6). To establish the aforementioned notion that baPWV reflects the ath-erosclerotic burden in the systemic arterial tree, studies to examine the association of baPWV with the severity of atherosclerosis at multiple sites in the arterial tree are needed. In the present study, Joo et al examined the association of baPWV with subclinical atherosclerosis not only in the carotid artery as assessed by ultrasound examination but also in the coronary arteries as assessed by computed tomography angiography in 773 subjects having components of the metabolic syndrome 7). They found that baPWV was higher in subjects with composite subclinical atherosclerosis than in those without subclinical atherosclerosis and concluded that baPWV has a modest diagnostic potential for subclin-ical atherosclerosis (i.e., the crude odds ratio to predict composite subclinical atherosclerosis was 1.40, although this was not significant after adjustments). On …