Heart failure with "mid-range" ejection fraction: a new clinical entity ?

The new entity of heart failure with mid-range ejection fraction (HFmrEF) is defined as clinical syndrome characterized by typical symptoms and signs of heart failure (HF), an EF of 40-49%, elevated natriuretic peptides and documentation of structural heart disease. Prevalence has been estimated at 10-20% of all patients with HF. Compared to the populations with reduced (HFrEF) and preserved (HFpEF) EF, patients with HFmrEF show in general intermediate clinical characteristics. However, coronary disease as aetiology of HF is similar in HFmrEF and HFrEF and significantly more prevalent than in HFpEF. Outcome is poor as in the other HF categories. Frequently, HFmrEF seems to be a transitory stage from or to HFrEF and HFpEF respectively. Preliminary data suggest a potential benefit of evidence-based drug treatment for HFrEF also in HFmrEF.