Epidemiology of hospitalized heart failure: differences and similarities between patients with reduced versus preserved ejection fraction.

Annually, more than 1 million patients are hospitalized for heart failure (HF), translating to high healthcare utilization and cost burden. Among patients with hospitalized HF (HHF), approximately 50% have HF with preserved ejection fraction (HFpEF) and 50% have HF with reduced ejection fraction (HFrEF), with the proportion of patients with HFpEF increasing with time. This article defines the epidemiologic landscape of patients with HHF, comparing and contrasting those with HFpEF and HFrEF, and identifies key areas that require further investigation. More complete characterization of these populations may be the first step to developing effective therapies.