Savarese G, et al. - Since therapy in heart failure (HF) is determined based on ejection fraction (EF), researchers determined the incidence, predictors, and prognostic significance of changes in EF in HF patients using logistic and Cox regressions. Participants were identified from the Swedish Heart Failure Registry and had ≥2 EF measurements. The participants were divided into heart failure with preserved ejection fraction (HFpEF) (EF ≥50%), heart failure with midrange ejection fraction (HFmrEF) (EF 40% to 49%), or heart failure with reduced ejection fraction (HFrEF) (EF <40%). One-fourth of HFrEF and HFmrEF patients showed increases in EF, and more than one-third of patients with HFpEF and HFmrEF exhibited decreases in EF. Use of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, female sex, cases of less severe HF, and comorbidities were the factors that predicted increased EF; decreased EF was predicted by diabetes, ischemic heart disease, and cases of more severe HF. A lower risk of mortality and/or HF hospitalizations was observed in relation to increased EF, while a higher risk was noted in relation to decreased EF.