Frequency, predictors, and prognosis of heart failure with improved left ventricular ejection fraction: a single‐centre retrospective observational cohort study

AIMS: An improved left ventricular ejection fraction (HFiEF) was observed across heart failure (HF) patients with a reduced or mid‐range ejection fraction (HFrEF or HFmrEF, respectively). We postulated that HFiEF patients are clinically distinct from non‐HFiEF patients. METHODS AND RESULTS: A total of 447 patients hospitalized due to a clinical diagnosis of HF (LVEF <50% at baseline) were enrolled from September 2017 to September 2019. Echocardiogram re‐evaluation was conducted repeatedly over 6 months of follow‐up after discharge. The primary endpoint included the composite of HF hospitalization and all‐cause mortality. Subjects (n = 184) with HFiEF (defined as an absolute LVEF improvement≥10%) were compared with 263 non‐HFiEF (defined by <10% improvement in LVEF) subjects. Multivariable Cox regression was performed and identified younger age, smaller left ventricular end diastolic dimension (LVEDD), beta‐blocker use, AF ablation and cardiac resynchronization therapy (CRT) as independent predictors of HFiEF. According to Kaplan–Meier analysis, HFiEF subjects had lower cardiac composite outcomes (P = 0.002) and all‐cause mortality (P = 0.003) than non‐HFiEF subjects. Multivariate Cox survival analysis revealed that non‐HFiEF (compared with HFiEF) was an independent predictor of both the primary endpoints (HR = 0.679, 95% CI: 0.451–0.907, P = 0.012), which was driven by all‐cause mortality (HR = 0.504, 95% CI: 0.256–0.991, P = 0.047). CONCLUSIONS: These data confirm that compared with non‐HFiEF, HFiEF is a distinct HF phenotype with favourable clinical outcomes.