Supra-normal and mildly reduced ejection fraction in women -An overlooked vulnerable subpopulation in heart failure

Background: Recently, patients with supra-normal left ventricular ejection fraction (snEF) are reported to have high risk of adverse outcomes, especially in women. We sought to evaluate sex-related differences in the association between LVEF and long-term outcomes in heart failure (HF) patients. Methods: The multicenter WET-HF Registry enrolled all patients hospitalized for acute decompensated HF (ADHF). We analyzed 3943 patients (age 77 years; 40.1% female) registered from 2006 to 2017. According to LVEF the patients were divided into the 3 groups: HF with reduced EF (HFrEF), mildly reduced EF (HFmrEF) and preserved EF. The primary endpoint was defined as the composite of cardiac death and ADHF rehospitalization after discharge. Results: In HFmrEF, implementation of guideline-directed medical therapy (GDMT) such as the combination of renin-angiotensin-system inhibitor (RASi) and β-blocker at discharge was significantly lower in women than men even after adjustment for covariates (p = 0.007). There were no such sex-related differences in HFrEF. Female sex was associated with higher incidence of the primary endpoint and ADHF rehospitalization after adjustment for covariates exclusively in HFmrEF. Restricted cubic spline analysis demonstrated a U-shaped relationship between LVEF and the hazard ratio of the primary endpoint showing higher event rate in HFmrEF and HFsnEF in women, but such relationship was not observed in men (p for interaction = 0.037). Conclusions: In women, mrEF and snEF were associated with worse long-term outcomes. Additionally, sex-related differences in the GDMT implementation for HFmrEF highlight the need for further exploration, which might lead to creation of sex-specific guidelines to optimize HF management.