A Novel Blood Pressure-independent Arterial Wall Stiffness Parameter; Cardio-Ankle Vascular Index (CAVI)

To measure the stiffness of the aorta, femoral artery and tibial artery noninvasively, cardio-ankle vascular index (CAVI) which is independent of blood pressure was developed. The formula for measuring this index is; CAVI=a{(2rho/DeltaP) x ln(Ps/Pd)PWV(2)} + b where, Ps and Pd are systolic and diastolic blood pressures respectively, PWV is pulse wave velocity between the heart and ankle, DeltaP is Ps - Pd, rho is blood density, and a and b are constants. This equation was derived from Bramwell-Hill's equation(1)), and stiffness parameter(2)). To elucidate the clinical utility of CAVI, the reproducibility and dependence on blood pressure were studied using VaSera (Fukuda Denshi Co., Ltd.). Furthermore, CAVI in…