A wide range of ejection fraction (EF) thresholds have been used to categorize patients with heart failure (HF) with "preserved" EF. Our goal was to characterize the clinical and echocardiographic differences among patients with cardiac structural/functional alterations and mid-range EF (mrEF) (EF 40-49%) compared to preserved EF (pEF) (EF ≥ 50%), irrespective of HF. Patients with an EF ≥ 40% and echocardiographic evidence of structural alterations (left atrial enlargement and/or left ventricular hypertrophy) and/or functional alterations (evidence of diastolic dysfunction) were retrospectively selected. Patients with acute coronary syndromes and ≥ moderate left sided valvular diseases were excluded. Patients were divided according to EF to pEF group (n = 578) and mrEF (n = 86). Patients with mrEF were twice as likely to be men, had higher prevalence of hyperlipidemia, diabetes and smoking, compared to patients with pEF. History of coronary artery disease (CAD) was more frequent among mrEF (50% vs. 28%, p < 0.0001, respectively), and highest among the subgroup of patients with HF (83% vs. 35%, p < 0.0001, respectively). Patients with mrEF had increased LV mass index (131 ± 35 vs. 120 ± 26 g/m2, p < 0.001), LV end diastolic diameter (55 ± 5 vs 51 ± 3, p < 0.0001), mitral E to e' ratio (16 ± 7 vs. 14 ± 5, p = 0.001), and left atrial systolic diameter (44 ± 5 mm vs. 42 ± 4 mm, p = 0.01. respectively). Patients with mrEF demonstrated worse structural and functional echocardiographic alterations and were more likely to be men and to have CAD compared to patients with pEF.
Keywords: Diastolic dysfunction; Echocardiography; Heart failure; Mid-range ejection fraction.