Evaluating aortic stiffness through an arm cuff oscillometric device: is validation against invasive measurements enough?

Abstract

Introduction Following the 2006 expert consensus document of the European Network for Noninvasive Investigation of Large Arteries [1], arterial stiffness and central pressure measurements should be considered as recommended tests for the evaluation of cardiovascular risk, particularly in patients in whom target organ damage is not discovered by routine investigations. Within the area of noninvasive methods, pulse wave recording and analysis either from central (ascending aorta, carotid artery) or peripheral (radial artery) sites have become popular, particularly after the release of dedicated commercial devices [2]. Theoretically, pulse wave analysis should allow calculation of at least three parameters related to arterial wall properties: central pulse pressure, central systolic pressure and the augmentation index (Aix). There is large consensus that these parameters should not be considered as direct measures of arterial stiffness, but rather as surrogate estimates. Conversely, most investigators [1] agree that pulse wave velocity (PWV) is the more direct measure of arterial stiffness. Unfortunately there are different definitions of PWV, and different measurement sites have been proposed while, at the same time, the number of published papers on the validity and prognostic value of carotid–femoral, aortic, brachial–ankle and local PWVs is constantly increasing. Carotid–femoral PWV (PWVcf), the ‘gold standard’ of arterial stiffness [1], and aortic PWV (PWVao) are supported by the largest amount of epidemiological evidence on their ability to predict cardiovascular events in specific subgroups of patients and, possibly, in the population at large. However, there is also increasing evidence that central Aix predicts allcause mortality in end-stage renal disease and cardiovascular events in hypertension and coronary artery disease [1].