Optimal Threshold of Left Ventricular Ejection Fraction for Aortic Valve Replacement in Asymptomatic Severe Aortic Stenosis: A Systematic Review and Meta‐Analysis

BACKGROUND: The optimal threshold of left ventricular ejection fraction (LVEF) that should prompt aortic valve replacement (AVR) in asymptomatic patients with high‐gradient severe aortic stenosis (AS) is controversial. The aim of this study was to assess the relationship between LVEF and mortality benefit in comparing early AVR versus watchful waiting in asymptomatic patients with severe AS. METHODS AND RESULTS: MEDLINE, Embase, Web of Science, and Google Scholar were searched for observational studies and randomized controlled trials on adults with asymptomatic severe AS. Severe AS was defined by a peak aortic velocity ≥4 m/s and/or mean aortic valve gradient ≥40 mm Hg and/or calculated aortic valve area <1.0 cm(2) or an indexed valve area <0.6 cm(2). Studies comparing AVR with conservative management were included and meta‐analysis on all‐cause mortality was performed. Ten eligible studies were identified with a total of 3332 patients. In 5 observational studies comparing early AVR versus watchful waiting, our meta‐analysis showed early AVR was associated with lower mortality with a hazard ratio (HR) of 0.41 (CI, 0.23–0.71; P<0.01). In 4 observational studies comparing AVR versus no AVR, our meta‐analysis showed AVR was associated with lower mortality with a HR of 0.31 (CI, 0.17–0.58; P<0.001). In a meta‐regression analysis pooling all 10 studies, there was no statistically significant correlation between study mean LVEF and the size of mortality benefit of AVR (P=0.83). CONCLUSIONS: Among asymptomatic patients with high‐gradient severe AS, AVR was associated with a mortality benefit across the spectrum of LVEF. Our study calls into question the need of an LVEF threshold for recommending AVR in this patient population.