Early Aortic Valve Replacement in Symptomatic Normal-Flow, LowGradient Severe Aortic Stenosis: A Propensity Score-Matched Retrospective Cohort Study

Background and Objectives: Aortic valve replacement (AVR) is considered a class I indication for symptomatic severe aortic stenosis (AS). However, there is little evidence regarding the potential benefits of early AVR in symptomatic patients diagnosed with normal-flow, low-gradient (NFLG) severe AS. Methods: Two-hundred eighty- one patients diagnosed with symptomatic NFLG severe AS (stroke volume index >= 35 mL/m(2), mean transaortic pressure gradient <40 mmHg, peak transaortic velocity <4 m/s, and aortic valve area <1.0 cm(2)) between January 2010 and December 2020 were included in this retrospective study. After performing 1:1 propensity score matching, 121 patients aged 75.1 +/- 9.8 years (including 63 women) who underwent early AVR within 3 months after index echocardiography, were compared with 121 patients who received conservative care. The primary outcome was a composite of all- cause death and heart failure (HF) hospitalization. Results: During a median follow-up of 21.9 months, 48 primary outcomes (18 in the early AVR group and 30 in the conservative care group) occurred. The early AVR group demonstrated a significantly lower incidence of primary outcomes (hazard ratio [HR], 0.52; 95% confidence interval [CI], 0.29-0.93; p=0.028); specifically, there was no significant difference in all-cause death (HR, 0.51; 95% CI, 0.23-1.16; p=0.110), although the early AVR group showed a significantly lower incidence of hospitalization for HF (HR, 0.43; 95% CI, 0.19-0.95, p=0.037). Subgroup analyses supported the main findings. Conclusions: An early AVR strategy may be beneficial in reducing the risk of a composite outcome of death or hospitalization for HF in symptomatic patients with NFLG severe AS. Future randomized studies are required to validate and confirm our findings.