ObjectiveTo assess the effects of comorbidities, fragility, and quality of life (QOL) on long-term prognosis in ambulatory patients with heart failure (HF) with midrange left ventricular ejection fraction (HFmrEF), an unexplored area.Patients and MethodsConsecutive patients prospectively evaluated at an HF clinic between August 1, 2001, and December 31, 2015, were retrospectively analyzed on the basis of left ventricular ejection fraction category. We compared patients with HFmrEF (n=185) to those with reduced (HFrEF; n=1058) and preserved (HFpEF; n=162) ejection fraction. Fragility was defined as 1 or more abnormal evaluations on 4 standardized geriatric scales (Barthel Index, Older Americans Resources and Services scale, Pfeiffer Test, and abbreviated-Geriatric Depression Scale). The QOL was assessed with the Minnesota Living with Heart Failure Questionnaire. A comorbidity score (0-7) was constructed. All-cause death, HF-related hospitalization, and the composite end point of both were assessed.ResultsComorbidities and QOL scores were similar in HFmrEF (2.41±1.5 and 30.1±18.3, respectively) and HFrEF (2.30±1.4 and 30.8±18.5, respectively) and were higher in HFpEF (3.02±1.5, P<.001, and 36.5±20.7, P=.003, respectively). No statistically significant differences in fragility between HFmrEF (48.6%) and HFrEF (41.9%) (P=.09) nor HFpEF (54.3%) (P=.29) were found. In univariate analysis, the association of comorbidities, QOL, and fragility with the 3 end points was higher for HFmrEF than for HFrEF and HFpEF. In multivariate analysis, comorbidities were independently associated with the 3 end points (P≤.001), and fragility was independently associated with all-cause death and the composite end point (P<.001) in HFmrEF.ConclusionComorbidities and fragility are independent predictors of outcomes in ambulatory patients with HFmrHF and should be considered in the routine clinical assessment of HFmrEF.