Heart failure with mid-range ejection fraction: a distinct clinical entity? Insights from the Trial of Intensified versus standard Medical therapy in Elderly patients with Congestive Heart Failure (TIME-CHF)

Aims: While the conditions of heart failure (HF) with reduced (HFrEF, LVEF < 40%) and preserved (HFpEF, LVEF ≥ 50%) left ventricular ejection fraction (LVEF) are well characterized, it is unknown whether patients with HF and mid-range LVEF (HFmrEF, LVEF 40-49%) have to be regarded as a separate clinical entity. The aim of this study was to characterize these three populations and to compare outcome and response to therapy.

Methods and results: The analysis was based on the Trial of Intensified versus standard Medical therapy in Elderly patients with Congestive Heart Failure (TIME-CHF) comprising a population with established HF including the whole spectrum of LVEF. Of the 622 patients, 108 (17%) were classified as having HFmrEF. This group was in general found to be 'intermediate' regarding clinical characteristics with a comparable and high burden of comorbidities and equally impaired quality of life but was more likely to have coronary artery disease as compared with the HFpEF group. During a median follow-up of 794 days, mortality was 39.7% without significant differences between groups. N-terminal pro-B-type natriuretic peptide (NT-proBNP)-guided as compared with standard therapy resulted in improved survival free of HF hospitalizations in HFrEF and HFmrEF, but not in HFpEF.

Conclusion: Although the 'intermediate' clinical profile of HFmrEF between HFrEF and HFpEF would support the conclusion that HFmrEF is a distinct clinical entity, we hypothesize that HFmrEF has to be categorized as HFrEF because of the high prevalence of coronary artery disease and the similar benefit of NT-proBNP-guided therapy in HFrEF and HFmrEF, in contrast to HFpEF.