Mid-range left ventricular ejection fraction: Clinical profile and cause of death in ambulatory patients with chronic heart failure

© 2017 Elsevier B.V. Background The intermediate group of patients with heart failure (HF) and mid-range left ventricular ejection fraction (HFmrEF) may constitute a specific phenotype, but a direct evidence is lacking. This study aimed to know whether this HF category is accompanied by a particular clinical phenotype and prognosis. Methods and results This study includes 3446 ambulatory patients with chronic HF from two national registries. According to EF at enrollment, patients were classified as reduced (HFrEF, < 40%), mid-range (HFmrEF, 40–49%) or preserved (HFpEF, ≥ 50%). Patients were followed-up for a median of 41 months and the specific cause of death was prospectively registered. Patients with HFmrEF represented 13% of population and they exhibited a phenotype closer to HFrEF, except for a higher rate of coronary revascularization and diabetes, and a less advanced HF syndrome. The observed all-cause mortality was higher among HFrEF (33.0%), and similar between HFmrEF (27.8%) and HFpEF (28.0%) (p = 0.012); however, the contribution of each cause of death differed significantly between categories (p < 0.001). After propensity score matching, the risk of cardiovascular death, HF death or sudden cardiac death did not differ between HFmrEF and HFrEF in paired samples; however, patients with HFmrEF were at higher risk of cardiovascular death (sHR 1.71, 95% CI 1.13–2.57, p = 0.011) and sudden cardiac death (sHR 2.73, 95% CI 1.07–6.98, p = 0.036) than patients with HFpEF. Conclusions Patients in the intermediate category of HFmrEF conform a phenotype closer to the clinical profile of HFrEF, and associated to higher risk of sudden cardiac death and cardiovascular death than patients with HFpEF.