Inappropriately high left-ventricular mass in asymptomatic mild-moderate aortic stenosis

Abstract

In some patients with aortic stenosis left-ventricular hypertrophy exceeds what is needed to sustain the hemodynamic load imposed by the aortic stenosis, a condition named inappropriately high left-ventricular mass (iLVM). Although iLVM is associated with increased mortality after aortic valve replacement, prevalence and covariates of iLVM in asymptomatic aortic stenosis are unknown. We analyzed baseline data from 1614 patients (67 ± 10 years, 51% hypertensive) recruited in the Simvastatin Ezetimibe in Aortic Stenosis study evaluating placebo-controlled combined simvastatin and ezetimibe treatment in asymptomatic mild-moderate aortic stenosis. iLVM was diagnosed by Doppler echocardiography as LVM greater than 28% of the expected LVM predicted from height, sex and stroke work. iLVM was detected in 268 patients (16.6%), irrespective of concomitant hypertension. Patients with iLVM had higher body weight, LVM and relative wall thickness, higher prevalence of systolic dysfunction (88 vs. 15%) and lower left-ventricular afterload (all P < 0.01) than patients with appropriate LVM in spite of comparable aortic stenosis severity. In multivariate analysis, all these five variables were independently associated with iLVM. The simple coexistence of low stress-corrected midwall shortening and left-ventricular hypertrophy was the best clinical model describing iLVM phenotype (sensitivity 72%, specificity 96%, area under the receiver operating characteristic curve 0.954). iLVM is common in asymptomatic mild-moderate aortic stenosis and unrelated to severity of aortic stenosis or presence of hypertension. iLVM was associated with combined concentric geometry and reduced left-ventricular myocardial contractility, suggesting iLVM in asymptomatic aortic stenosis as a marker of more advanced myocardial disease.