Application of a Novel Two-Dimensional Echocardiographic Calcium Quantification Method to Assess All Severities of Aortic Stenosis

Abstract

Aortic valve (AV) calcification (AVC) is a strong predictor of aortic stenosis (AS) severity. The two-dimensional AVC (2D-AVC) ratio, a gain-independent ratio composed of the average pixel density of the AV and the aortic annulus, has previously shown strong correlations with two-dimensional (2D) echocardiographic hemodynamic parameters for severe AS and AVC by cardiac computed tomography. We hypothesize that the 2D-AVC ratio correlates with hemodynamic parameters in all severities of AS. A total of 285 patients with a normal AV (n=49), aortic sclerosis (n=75), or mild (n=38), moderate (n=72), or severe (n=51) AS undergoing 2D echocardiography were retrospectively evaluated, and the 2D-AVC ratios were correlated to mean AV gradient, peak AV velocity, AV area, and dimensionless index. The 2D-AVC ratios of various AS severities were compared against each other via area under the curve (AUC) analysis. The 2D-AVC ratio is strongly correlated with mean AV gradient (r=0.79, P<.0001) and peak AV velocity (r=0.78, P<.0001). There was moderate correlation with the AV area (r=-0.58, P<.0001) and dimensionless index (r=-0.67, P<.0001) across all AS severities. The 2D-AVC ratio also distinguished nonmoderate AS (mild AS+normal AV) from moderate or greater (moderate+severe) AS (AUC=0.93) and moderate versus severe AS (AUC=0.88). The 2D-AVC ratio exhibits moderate to strong correlation with 2D echocardiographic hemodynamic parameters across all severities of AS.