An analysis of individual-level information of heart failure (HF) patients revealed that there was a left ventricular ejection fraction (LVEF) threshold of around 40% to 50% where the pattern of patient characteristics changed, and event rates began to increase compared with higher LVEF values. The analysis was performed on 33 699 HF patients enrolled in 6 randomized controlled trials with reduced and preserved ejection fraction. As LVEF increased, age, the proportion of women, body mass index, systolic blood pressure, and prevalence of atrial fibrillation and diabetes increased, whereas ischemic pathogenesis, estimated glomerular filtration rate, and NT-proBNP (N-terminal pro-B-type natriuretic peptide) decreased. As LVEF increased >50%, age and the proportion of women continued to increase, and ischemic pathogenesis and NT-proBNP decreased, but other characteristics did not change meaningfully. The incidence of most clinical outcomes (except noncardiovascular death) decreased as LVEF increased, with a LVEF inflection point of around 50% for all-cause and cardiovascular death, around 40% for pump failure death, and around 35% for HF hospitalization. Higher than those thresholds, there was little further decline in the incidence rate. In patients with a high-normal LVEF, there were no structural differences suggestive of amyloidosis, consistent with NT-proBNP levels in a subset of patients with echocardiographic data. The findings support current upper LVEF thresholds defining HF with mildly reduced ejection fraction based on prognosis. Source: https://www.ahajournals.org/
