Brachial-Ankle Pulse Wave Velocity: Background, Method, and Clinical Evidence

The populations of many developed countries are becoming progressively older. In aged societies, assessment of total vascular risk is critically important, because old age is usually associated with multiple risks. In this regard, pulse wave velocity (PWV) could be a global cardiovascular marker, since it increases with advancing age, high blood pressure, hyperglycaemia, and other traditional risks, summating cardiovascular risks. Carotid-femoral PWV has been widely applied in Western countries and has been used as a gold-standard PWV measure. However, this measure has never been implemented by general practitioners in Japan, possibly because of methodological difficulties. The life expectancy of Japanese people is now the highest in the world, and the establishment of an adequate total vascular risk measure is an urgent need. Against this background, brachial-ankle PWV was developed at the beginning of this century.

Measurement of this parameter is easy, and its reproducibility is good. Moreover, the generality of the methodology is guaranteed. Brachial-ankle PWV has been reported to consistently increase with most traditional cardiovascular risk factors except dyslipidaemia. A meta-analysis of cohort studies including various levels of risk has shown that a 1 m/s increase in brachial-ankle PWV is associated with a 12% increase in the risk of cardiovascular events. Moreover, simultaneous evaluation of the ankle-brachial index could allow further risk stratification of high-risk individuals, who are common in aged societies. This unique feature is indispensable for the management of aged populations, who usually are exposed to multiple risks and have polyvascular diseases. This evidence, however, is chiefly derived from East Asian countries. The collection of data from Caucasian populations, therefore, remains a task for the future.

Brachial-ankle PWV has the potential to become a measure of arterial stiffness worldwide.