Resting echocardiographic predictors for true-severe aortic stenosis in patients with low-gradient severe aortic stenosis: A dobutamine stress echocardiography study.

Abstract

Dobutamine stress echocardiography (DSE) is not always feasible in patients with low-gradient severe aortic stenosis (LG-SAS), and there are limited data available on the resting echocardiographic predictors for true-severe aortic stenosis (TSAS). This study investigated resting echocardiographic predictors for TSAS. Clinical data of 106 LG-SAS patients who underwent DSE were retrospectively analyzed. LG-SAS was defined as an aortic valve area index (AVAi)<.6cm2 /m2 , and a mean AV pressure gradient<40mm Hg. The velocity ratio (VR) was calculated as the peak left ventricular outflow tract velocity/peak AV velocity. TSAS was defined as a projected AVAi<.6cm2 /m2 . The mean age was 79.3 ± 7.3 years, and 45 (42.5%) were men. The resting AV data were as follows: AVAi, .50 ± .07 cm2 /m2 ; mean AV pressure gradient, 23.0 ± 7.4mm Hg; and VR, .25 ± .05. The projected AVAi was .58 ± .09 cm2 /m2 , and TSAS was documented in 65 (61.3%) patients. In multivariate analysis, the independent predictors of TSAS were AVAi (p=0.012) and VR (p=0.004) with respective best cut-off values of .52cm2 /m2 and .25 on receiver-operating characteristic curve analysis. According to incremental numbers of the predictors, correct classification percentages of TSAS significantly increased with the Cochran-Armitage trend test (16.2% in no predictors, 65.2% in one predictor, and 95.7 % in two predictors; p<0.001). Resting AVAi and VR were independent predictors of TSAS in LG-SAS patients. The true severity might be predictable using the combination of resting parameters.