Aortic valve replacement and mortality in asymptomatic individuals with severe aortic stenosis and left ventricular hypertrophy.

OBJECTIVES

Indications for aortic valve replacement (AVR) in severe asymptomatic aortic stenosis (AS) differ for individuals with normal versus low or decreasing left ventricular ejection fraction (LVEF). Conceptually, the development of left ventricular hypertrophy (LVH) could also indicate ventricular injury and potential need for earlier AVR.

METHODS

Initially, 1 232 492 echocardiography reports from 12 hospitals were identified; then previously validated, open-source natural language processing modules were applied to identify aortic gradients, LVEF, and the presence of LVH. These reports were linked to mortality data, key comorbidities, and date of any AVR. We then performed physician chart reviews, identified asymptomatic individuals with normal flow severe AS, LVEF ≥ 55%, and LVH, and confirmed key clinical data manually. To assess the association between AVR and mortality, Cox proportional hazards models considering treatment status (i.e., AVR or not considered as a time-dependent covariate) were used with the index echocardiogram as time zero.

RESULTS

After application of eligibility criteria, 607 unique, confirmed asymptomatic individuals remained for the primary analysis. After adjustment, and accounting for the time-dependence of AVR, AVR was associated with reduced mortality (hazard ratio 0.37; 95% confidence interval 0.25-0.55, P < 0.0001).

CONCLUSIONS

AVR was associated with reduced mortality for patients with severe asymptomatic AS, preserved LVEF, and LVH. This is the largest known analysis of aortic valve replacement outcomes in individuals with severe aortic stenosis and left ventricular hypertrophy. As clinical guidelines for intervention in asymptomatic severe aortic stenosis expand, left ventricular hypertrophy is easier to assess than myocardial fibrosis and may be a useful marker for patients who need to be prioritized. These results raise the potential of more proactive AVR in individuals with LVH, even among asymptomatic individuals with normal LVEF.