In patients with acute heart failure admitted with LVEF ≤40%, 15% had HFimpEF at predischarge reassessment, and HFimpEF was independently associated with lower 1-year and 5-year all-cause mortality risk compared with patients with nonimproved LVEF.
Key Findings
Results
Approximately 14.9% of acute heart failure patients admitted with LVEF ≤40% achieved heart failure with improved ejection fraction (HFimpEF) by hospital discharge.
Overall population included 779 patients with LVEF ≤40% at admission.
HFimpEF was defined as LVEF >40% at discharge with an improvement in LVEF ≥10%.
116 of 779 patients (14.9%) met the HFimpEF criteria at discharge.
Data were collected retrospectively with ≥2 in-hospital echocardiographic evaluations required for inclusion.
Results
Valvular heart disease was an independent predictor of in-hospital HFimpEF.
Odds ratio for valvular heart disease as a predictor of HFimpEF was 3.460 (P=0.001).
This was identified through multivariable logistic regression analysis.
Valvular pathogenesis was the strongest positive predictor of HFimpEF among those identified.
Results
Lower left ventricular volumes at admission were independently associated with higher likelihood of achieving HFimpEF.
Odds ratio was 0.957 per 1 mL/m² increase in left ventricular volumes (P<0.001).
This indicates that less severe left ventricular remodeling predicted in-hospital LVEF improvement.
Finding was identified through multivariable logistic regression.
Results
Absence of right ventricular dysfunction was an independent predictor of in-hospital HFimpEF.
Odds ratio for absence of right ventricular dysfunction was 0.518 (P=0.017).
Right ventricular dysfunction was thus associated with lower likelihood of achieving HFimpEF.
This was one of three independent predictors identified in the multivariable model.
Results
LVEF at admission was not associated with 1-year all-cause death.
Admission LVEF value alone did not predict 1-year mortality in this cohort.
This finding contrasts with the prognostic value of in-hospital LVEF trajectory.
The result underscores the importance of reassessing LVEF trajectory rather than relying solely on admission values.
Results
HFimpEF was independently associated with significantly lower 1-year all-cause mortality compared with patients with nonimproved LVEF.
Hazard ratio for 1-year all-cause death in HFimpEF patients was 0.324 (P=0.008).
This represents approximately a 68% relative reduction in 1-year mortality risk.
Patients were classified according to in-hospital LVEF trajectory for this analysis.
Association remained independent after multivariable adjustment.
Results
HFimpEF was independently associated with lower 5-year all-cause mortality compared with patients with nonimproved LVEF.
Hazard ratio for 5-year all-cause death in HFimpEF patients was 0.584 (P=0.013).
This represents approximately a 42% relative reduction in 5-year mortality risk.
The prognostic benefit of HFimpEF extended beyond the first year of follow-up.
Results
The majority of patients who achieved HFimpEF maintained LVEF >40% at 12-month follow-up, though a minority reverted to reduced ejection fraction.
Among patients discharged with HFimpEF who were reevaluated after 12 months, 86% maintained LVEF >40%.
14% of patients with HFimpEF at discharge showed LVEF ≤40% again at the 1-year ambulatory follow-up visit.
LVEF trajectories were assessed at a follow-up ambulatory visit at 1 year after discharge.
What This Means
This research suggests that among patients hospitalized for acute heart failure with a weak heart pump (measured by a low ejection fraction, or LVEF, of 40% or less), about 1 in 7 patients showed meaningful improvement in heart pump function by the time of discharge — a condition called 'heart failure with improved ejection fraction' (HFimpEF). Patients most likely to experience this improvement were those whose heart failure was caused by valve problems, those with less enlarged or damaged hearts at admission, and those without additional dysfunction of the right side of the heart.
This research suggests that tracking how a patient's LVEF changes during hospitalization — rather than simply measuring it at admission — provides important prognostic information. Patients who achieved HFimpEF during their hospital stay had dramatically better survival outcomes: roughly 68% lower risk of dying within 1 year and 42% lower risk of dying within 5 years compared to patients whose LVEF did not improve. Notably, the LVEF value at admission alone did not predict 1-year mortality, reinforcing the value of repeat echocardiographic assessment during hospitalization.
This research also suggests that the improvement in heart function seen at discharge tends to be durable: 86% of HFimpEF patients who were re-evaluated after 12 months maintained improved ejection fraction, while 14% reverted to reduced function. These findings highlight the potential importance of routinely reassessing heart function before discharge in acute heart failure patients, as early recovery of cardiac function appears to mark a meaningfully different and more favorable disease course.
Cocianni D, Barbisan D, Perotto M, Contessi S, Savonitto G, Rizzi J, et al.. (2026). In-Hospital Improved Left Ventricular Ejection Fraction and Prognosis in Acute Heart Failure.. Journal of the American Heart Association. https://doi.org/10.1161/JAHA.125.048255