Rehospitalization burden and morbidity risk in patients with heart failure with mid-range ejection fraction

Heart failure with mid-range ejection fraction (HFmrEF) has been proposed as a distinct HF phenotype, but whether patients on this category fare worse, similarly, or better than those with HF with reduced EF (HFrEF) or preserved EF (HFpEF) in terms of rehospitalization risks over time remains unclear.

We prospectively included 2961 consecutive patients admitted for acute HF (AHF) in our institution. Of them, 158 patients died during the index admission, leaving the sample size to be 2803 patients. Patients were categorized according to their EF: HFrEF if EF ≤ 40% (n = 908, 32.4%); HFmrEF if EF = 41-49% (n = 449, 16.0%); and HFpEF if EF ≥ 50% (n = 1446, 51.6%). Covariate-adjusted incidence rate ratios (IRRs) were used to evaluate the association between EF status and recurrent all-cause and HF-related admissions. At a median follow-up of 2.6 years (inter-quartile range: 1.0-5.3), 1663 (59.3%) patients died, and 6035 all-cause readmissions were registered in 2026 patients (72.3%), 2163 of them HF related. Rates of all-cause readmission per 100 patients-years of follow-up were 150.1, 176.9, and 163.6 in HFrEF, HFmrEF, and HFpEF, respectively (P = 0.097). After multivariable adjustment, when compared with that of patients with HFrEF and HFpEF, HFmrEF status was not significantly associated with a different risk of all-cause readmissions (IRR = 0.99; 95% confidence interval [CI], 0.77-1.27; P = 0.926; and IRR = 0.93; 95% CI, 0.74-1.18; P = 0.621, respectively) or HF-related readmissions (IRR = 1.06; 95% CI, 0.77-1.46; P = 0.725; and IRR = 1.11; 95% CI, 0.82-1.50; P = 0.511, respectively).

Following an admission for AHF, patients with HFmrEF had a similar rehospitalization burden and a similar risk of recurrent all-cause and HF-related admissions than had patients with HFrEF or HFpEF. Regarding morbidity risk, HFmrEF seems not to be a distinct HF phenotype.