Ejection fraction at hospital admission stratifies mortality risk in HFmrEF patients aged ≥ 70 years: a retrospective analysis from a tertiary university institution.

Background: During the last few years, increasing focus has been placed on heart failure with mildly reduced ejection fraction (HFmrEF), an intermediate phenotype from preserved to reduced ejection fraction (EF). However, clinical features and outcome of HFmrEF in elderly patients aged ≥ 70 yrs have been poorly investigated.

Methods: The present study retrospectively included all consecutive patients aged ≥ 70 yrs discharged from our Institution with a first diagnosis of HFmrEF, between January 2020 and November 2020. All patients underwent transthoracic echocardiography. The primary outcome was all-cause mortality, while the secondary one was the composite of all-cause mortality + rehospitalization for all causes over a mid-term follow-up.

Results: The study included 107 HFmrEF patients (84.3 ± 7.4 yrs, 61.7% females). Patients were classified as "old" (70-84 yrs, n = 55) and "oldest-old" (≥ 85 yrs, n = 52) and separately analyzed. As compared to the "oldest-old" patients, the "old" ones were more commonly males (58.2% vs 17.3%, p < 0.001), with history of coronary artery disease (CAD) (54.5% vs 15.4%, p < 0.001) and significantly lower EF (43.5 ± 2.7% vs 47.3 ± 3.6%, p < 0.001) at hospital admission. Mean follow-up was 1.8 ± 1.1 yrs. During follow-up, 29 patients died and 45 were re-hospitalized. Male sex (HR 6.71, 95% CI 1.59-28.4), history of CAD (HR 5.37, 95% CI 2.04-14.1) and EF (HR 0.48, 95% CI 0.34-0.68) were independently associated with all-cause mortality in the whole study population. EF also predicted the composite of all-cause mortality + rehospitalization for all causes. EF < 45% was the best cut-off value to predict both outcomes.

Conclusions: EF at hospital admission is independently associated with all-cause mortality and rehospitalization for all causes in elderly HFmrEF patients over a mid-term follow-up.