Predictors and Prognostic Factors of Heart Failure with Improved Ejection Fraction

Background: Heart failure with reduced ejection fraction (HFrEF) patients who have improved ejection fraction have a better prognosis than those with persistently reduced ejection fraction. This study aimed to analyze the predictors for progression of patients with HFrEF to heart failure with improved ejection fraction (HFimpEF), as well as their characteristics and analyze predictors for prognosis. Methods: A retrospective analysis was conducted on 1251 patients with HFrEF at baseline, who also had a second echocardiogram ≥3 months. After left ventricular ejection fraction (LVEF) reassessment, patients were separated into the HFimpEF group (n = 408) and the persistent HFrEF group (n = 611). The primary endpoint was a composite of cardiovascular death or heart failure hospitalization. Results: Multivariate logistic regression showed that without history of alcohol consumption (OR: 0.47, 95% CI: 0.28–0.78), non-New York Heart Association (NYHA) class III–IV (OR: 0.28, 95% CI: 0.15–0.52), without dilated cardiomyopathy (OR: 0.47, 95% CI: 0.26–0.84), concomitant hypertension (OR: 1.53, 95% CI: 1.02–2.29), β-blockers use (OR: 2.29, 95% CI: 1.54–3.43), and lower uric acid (OR: 0.999, 95% CI: 0.997–1.000) could predict LVEF improvement. Kaplan-Meier curves demonstrated that HFimpEF patients had a significantly lower incidence of adverse events than HFrEF patients (log Rank p < 0.001). Multivariate Cox regression found that older age (HR: 1.04, 95% CI: 1.02–1.06), NYHA class III–IV (HR: 2.25, 95% CI: 1.28–3.95), concomitant valvular heart disease (HR: 1.98, 95% CI: 1.01–3.85), and higher creatinine (HR: 1.003, 95% CI: 1.001–1.004) were independent risk factors for the primary endpoint in HFimpEF patients. Conclusions: HFrEF patients without a history of alcohol consumption, non-NYHA class III–IV, without dilated cardiomyopathy, concomitant hypertension, β-blockers use, and lower uric acid were more likely to have LVEF improvement. Although the prognosis of HFimpEF patients was better than that of HFrEF patients, older age, NYHA class III–IV, concomitant valvular heart disease, and higher creatinine were still risk factors for cardiovascular events in HFimpEF patients.