Prognostic significance of indexed stroke volume in asymptomatic patients with moderate or severe aortic stenosis and preserved left ventricular ejection fraction

Introduction: When to intervene in asymptomatic patients with moderate or severe aortic stenosis (AS) and preserved left ventricular ejection fraction (LVEF) has not yet been determined. In patients with AS, low flow through the aortic valve is defined as indexed stroke volume (SVi) ≤35 ml/m2 . Our work aimed to determine the relationship between SVi and all-cause mortality in asymptomatic patients with moderate or severe AS, concordantly high mean gradient across the aortic valve (Pmean), and preserved LVEF. Methods: The study included 121 asymptomatic patients (69 men, mean age 66±11) with moderate-to-severe AS (aortic valve area ≤1.5 cm2 ), concordantly high Pmean (≥30 mmHg), and preserved LVEF (≥50%). The median follow-up was 38 months (IQR 35-42 months). Results: Ten patients (8%) died during the follow-up. All-cause mortality was significantly higher in the group of AS-patients with SVi ≤35 ml/m2 compared to those with SVi >35 ml/m2 (15% vs. 4%, p<0.045). The cumulative incidence of all-cause mortality was significantly higher in the group of AS-patients with SVi ≤35 ml/m2 compared to those with SVi >35 ml/m2 (log-rank p=0.035). The group of AS-patients with SVi ≤35 ml/m² had a 3.8-fold higher risk of all-cause mortality during long-term follow-up compared with those with SVi >35 ml/m² (HR: 3.845; 95% CI: 1.004-14.871; p=0.041). Conclusion: Left ventricular SVi may be a significant predictor of all-cause mortality during long-term follow-up in asymptomatic patients with moderate or severe AS, concordantly elevated Pmean, and preserved LVEF. Larger studies are needed to confirm these findings.