Heart failure with mid-range ejection fraction: pro and cons of the new classification of Heart Failure by European Society of Cardiology guidelines

Currently, the assessment of left ventricular ejection fraction (LVEF) is the cornerstone of the classification of patients with heart failure (HF). The mid-range LVEF (HFmrEF) category was identified in an attempt to uncover specific characteristics of these patients. So far, the analysis of trials, registries, and observational studies have demonstrated that patients with mid-range LVEF belong to a patient cohort with generally intermediate clinical profile as compared with other groups but with a remarkable variety of intrinsic phenotypes. This is due to the limitations of LVEF as the sole criterion to categorize patients with HF and characterize their prognosis, above all when it is >40%. To better define the HFmrEF phenotype, it is reasonable to consider other parameters, such as LVEF changes over time, HF aetiology, co-morbidities, and other imaging parameters. A multiparametric evaluation may contextualize a patient with HFmrEF in a more defined phenotype with a specific prognosis.