Moderate Aortic Valve Stenosis Is Associated With Increased Mortality Rate and Lifetime Loss: Systematic Review and Meta-Analysis of Reconstructed Time-to-Event Data of 409 680 Patients

BACKGROUND: The mortality risk attributable to moderate aortic stenosis (AS) remains incompletely characterized and has historically been underestimated. We aim to evaluate the association between moderate AS and all-cause death, comparing it with no/mild AS (in a general referral population and in patients with heart failure with reduced ejection fraction). METHODS AND RESULTS: A systematic review and pooled meta-analysis of Kaplan–Meier-derived reconstructed time-to-event data of studies published by June 2023 was conducted to evaluate survival outcomes among patients with moderate AS in comparison with individuals with no/mild AS. Ten studies were included, encompassing a total of 409 680 patients (11 527 with moderate AS and 398 153 with no/mild AS). In the overall population, the 15-year overall survival rate was 23.3% (95% CI, 19.1%–28.3%) in patients with moderate AS and 58.9% (95% CI, 58.1%–59.7%) in patients with no/mild aortic stenosis (hazard ratio [HR], 2.55 [95% CI, 2.46–2.64]; P<0.001). In patients with heart failure with reduced ejection fraction, the 10-year overall survival rate was 15.5% (95% CI, 10.0%–24.0%) in patients with moderate AS and 37.3% (95% CI, 36.2%–38.5%) in patients with no/mild AS (HR, 1.83 [95% CI, 1.69–2.0]; P<0.001). In both populations (overall and heart failure with reduced ejection fraction), these differences correspond to significant lifetime loss associated with moderate AS during follow-up (4.4 years, P<0.001; and 1.9 years, P<0.001, respectively). A consistent pattern of elevated mortality rate associated with moderate AS in sensitivity analyses of matched studies was observed. CONCLUSIONS: Moderate AS was associated with higher risk of death and lifetime loss compared with patients with no/mild AS.