In‐Hospital Improved Left Ventricular Ejection Fraction and Prognosis in Acute Heart Failure

Background The in‐hospital trajectories of left ventricular ejection fraction (LVEF) in patients admitted for acute heart failure have been poorly investigated. We sought to assess the rate of heart failure with improved ejection fraction (HFimpEF) at discharge in acute heart failure, to identify predictors of HFimpEF and to evaluate the association of HFimpEF with outcome. Methods We retrospectively enrolled patients admitted for acute heart failure, with ≥2 in‐hospital echocardiographic evaluations of LVEF and with LVEF ≤40% at admission. HFimpEF was defined as LVEF >40% at discharge, with an improvement in LVEF ≥10%. The primary end point was 1‐year all‐cause death. Trajectories of LVEF were also assessed at follow‐up ambulatory visit at 1 year after discharge. Results The overall population included 779 patients with LVEF ≤40% at admission; at discharge, 14.9% had HFimpEF. The independent predictors of HFimpEF were valvular heart disease (odds ratio, 3.460; P =0.001), lower left ventricular volumes (odds ratio, 0.957 per 1 mL/m 2 increase; P <0.001), and absence of right ventricular dysfunction (odds ratio, 0.518; P =0.017). LVEF at admission was not associated with 1‐year all‐cause death. When patients were classified according to the in‐hospital LVEF trajectory, HFimpEF was independently associated with a lower risk of 1‐year (hazard ratio [HR], 0.324; P =0.008) and 5‐year all‐cause death (HR, 0.584; P =0.013). Among patients discharged with HFimpEF who were reevaluated after 12 months, 86% maintained LVEF >40%, while 14% showed again LVEF ≤40%. Conclusions In patients with acute heart failure admitted with LVEF ≤40%, 15% had HFimpEF at predischarge reassessment. Valvular pathogenesis of heart failure with reduced ejection fraction, absent right ventricular dysfunction and less severe left ventricular remodeling were associated with higher likelihood of in‐hospital HFimpEF. One‐year and 5‐year mortality risk was lower in patients with HFimpEF compared with patients with nonimproved LVEF.