Park CS, et al. - Researchers studied clinical features, outcomes, and medical therapy in patients with heart failure with improved ejection fraction (HFiEF) in the KorAHF study, which included 5,625 consecutive patients hospitalized for acute HF. Baseline and follow-up echocardiography at 12 months was performed in 5,103 patients and 2,302 patients, respectively. Different HF phenotypes were defined: persistent HF with reduced ejection fraction (HFrEF; left ventricular ejection fraction [LVEF] ≤ 40% at baseline and at 1-year follow-up), HFiEF (LVEF ≤ 40% at baseline and improved up to 40% at 1-year follow-up), HF with midrange ejection fraction (LVEF between 40% and < 50%), and HF with preserved ejection fraction (LVEF ≥ 50%). Findings revealed HFiEF as a distinct entity with better clinical outcomes vs other phenotypes. β-blockers may offer some benefits for these patients. Positive predictors of HFiEF were younger age, female sex, de novo HF, hypertension, atrial fibrillation, and β-blocker use; negative predictors included diabetes mellitus and ischemic heart disease.