Analyzing Short and Medium-Term Morbidity and Mortality in Patients with Heart Failure and Borderline Ejection Fraction (EF: 40-49%).

Introduction: Heart failure with moderately impaired ejection fraction (HFmEF) has garnered increasing attention in recent years. However, understanding this new phenotype, particularly concerning morbidity and mortality, remains limited. Materials and Methods: A prospective, observational, and single-center study spanning 26 months was conducted on 204 patients with HFmEF selected from 447 patients with chronic heart failure (CHF) categorized based on their left ventricular ejection fraction (LVEF): HF with reduced ejection fraction (HFrEF) if LVEF ≤ 40% (n = 173) and HF with preserved ejection fraction (HFpEF) if LVEF ≥ 50% (n = 70). This study included a detailed evaluation of factors precipitating cardiovascular (CV) death and rehospitalizations in patients with HFmEF. Results: After a mean follow-up of 431 days in the HFmEF patient group, our results indicated that CV mortality at six months was 2.5%, and at one year, it was 5.9%. Prognostic factors for survival included chronic kidney disease, blood glucose level > 1.4g/l, presence of moderate to severe secondary mitral insufficiency, sphericity index < 1.7, elevated pulmonary vascular resistance, and resistance to diuretic treatment. HF rehospitalization rates at 6 and 12 months were 2.5% and 8.3%, respectively. Predictive factors for HF rehospitalizations included diabetes, hemoglobin level < 13g/dl, left atrial volume > 34 ml/m3-, mitral S-wave < 0.05cm/s, non-improvement of global longitudinal strain, and resistance to diuretic treatment. Conclusion: This category of HF remains underrecognized and neglected by practitioners, and its prognosis is formidable, especially in the presence of adverse prognostic factors.