Heartbeat: Time to switch from aortic valve area to aortic valve index?

Abstract

Many patients with severe symptomatic aortic stenosis (AS) present for medical care late in the disease course, at a time point when outcomes after surgical or transcatheter aortic valve replacement may not be optimal. The diagnosis of AS is often missed on physical examination by primary care providers.1 Even when an echocardiogram is obtained, discrepancies in measures of AS severity can lead to confusion and failure to refer patients for appropriate intervention. In an effort to use a systems-based approach to improving diagnosis of severe AS, Bradley and colleagues looked at the accuracy of echocardiographic measures of AS severity in over 77 thousand patients over a 4 year period in a single US-based healthcare organisation.2 A combined assessment, using peak velocity, mean gradient, and the dimensionless index (simpler surrogate for aortic valve area [AVA}), provided the best sensitivity (92%) and specificity (99%) for diagnosis of severe AS compared with any single measure alone. (figure 1) Figure 1 Schematic of echocardiographic measures of aortic stenosis as the measurement of left ventricular outflow tract (LVOT) diameter is squared in the …