Prevalence of Left Ventricular Hypertrophy Caused by Systemic Hypertension Preceding the Development of Severe Aortic Stenosis

Abstract

It is generally assumed that left ventricular (LV) hypertrophy in aortic stenosis (AS) is a compensatory adaptation to chronic outflow obstruction. The advent of transcutaneous aortic valve replacement has stimulated more focus on AS in older patients, most of whom have antecedent hypertension. Accordingly, our aim was to investigate the interaction between hypertension and AS on LV remodeling in contemporary practice. We studied consecutive patients referred for echocardiograms with initial aortic valve (AV) peak velocity <3.0 m/s and a peak velocity of >3.5 m/s on a subsequent study performed at least 5 years later. LV size and geometry were measured echocardiographically. Midwall fractional shortening (FSmw) and peak systolic stress were calculated from 2-dimensional echocardiographic and Doppler data. Of 80 patients with progressive AS, 59% were women with mean age 82 ± 9 years. The average interval between the 2 echocardiograms was 5.9 ± 1.8 years. During the study period, peak velocity increased from 2.5 ± 0.4 to 4.2 ± 0.6 m/s (p < 0.01) and LV mass indexed to body surface area increased from 80 ± 28 to 122 ± 51 g/m2 (p < 0.01) with a corresponding shift from normal or concentric LV remodeling geometry to concentric hypertrophy. There was no correlation between change in LV mass index and AV mean gradient or valvulo-arterial impedance. However, change in LV mass index did correlate positively with initial peak velocity and inversely with initial LV mass. Plots of FSmw against circumferential stress at baseline and follow-up suggest that systolic function more than compensates for increasing load in many patients. In conclusion, most patients seen in our practice with severe AS have antecedent hypertension and LV remodeling at a time when outflow obstruction is mild. LV remodeling worsens in parallel with worsening severity of AS. Remodeling in these patients features increasing concentric remodeling of the LV, rather than LV dilation. Systolic function, as assessed by FSmw, remains compensated, or even improves relative to afterload, during progression of AS. Given these findings, we speculate that regression of LV hypertrophy to normal will not be affected by transcutaneous aortic valve replacement because LV hypertrophy preceded hemodynamically severe AS.