P6536Comparison of characteristics and 3-year outcomes in patients with acute heart failure with preserved, mid-range, and reduced ejection fraction

Background: Clinical characteristics and outcomes of acute heart failure (AHF) according to left ventricular ejection fraction (LVEF) have not been fully elucidated. Especially, patients with borderline LVEF were not well represented in previous clinical trials and registries, and thus this is a grey zone with scarce data requiring further empirical characterization. Purpose: We performed a comprehensive comparison of the epidemiology, pattern of in-hospital managements, and clinical outcomes with predictors in patients with AHF with different LVEF categories. Methods and results: The Korean Acute Heart Failure registry is a prospective multicenter cohort enrolling 5,320 hospitalized patients with AHF classified based on LVEF according to the 2016 European Society of Cardiology guidelines. We divided patients into three groups; LVEF <40% as HF with reduced ejection fraction (HFrEF), LVEF ≥50%, as HF with preserved EF (HFpEF) and borderline LVEF 40%–50%.as HF with mid-range EF (HFmrEF). Fifty-nine percent of patients had HFrEF, 16% had HFmrEF, and 25% had HFpEF. Compared to patients with HFrEF, those with HFpEF were older, more often female, and more likely to have non-ischemic aetiology. Patients with HFmrEF showed epidemiological profiles intermediate between HFrEF and HFpEF, and had a propensity to present de-novo HF with ischemic aetiology. Patients with lower LVEF had worse short-term outcomes; all-cause in-hospital mortality of HFrEF, HFmrEF, and HFpEF was 5.1%, 3.6%, and 3.0% respectively. Discharged patients with AHF showed poor 3-year all-cause mortality up to 38%, which was comparable between the LVEF subgroups (P=0.623). Notably, ischemic aetiology was associated with the worst long-term outcome only in patients with HFrEF.