Characteristics and prognosis of heart failure with improved compared with persistently reduced ejection fraction: A systematic review and meta-analyses:

AimsWe assessed the clinical characteristics and prognosis of chronic heart failure patients with improved ejection fraction (HFIEF) compared with persistently reduced ejection fraction (HFpREF) after evidence-based therapy.Methods and resultsWe performed a meta-analysis including 24 eligible observational studies comparing 2663 HFIEF (≥5% left ventricular ejection fraction (LVEF) improvement) versus 8355 HFpREF patients who received recommended drug therapy, cardiac resynchronization therapy and/or intracardiac defibrillator. LVEF was assessed at baseline and reassessed after 19 ± 19 months. The primary endpoints were all-cause mortality and appropriate shocks. The mean duration of follow-up was 39 ± 12 months. Among HFIEF patients, LVEF improved 16.3 percentage points (95% confidence interval 15.9–16.6, p < 0.0001). Compared with HFpREF patients, HFIEF patients had a comparable mean age (60.9 years vs. 62.4 years, p = 0.11), were more often women (33% vs. 25%), had a higher prevalence of non-ischaemic h...