Association of left ventricular ejection fraction with risk of cardiovascular diseases: a prospective cohort study.

Left ventricular ejection fraction (LVEF) is the most ubiquitous parameter in cardiac imaging examinations, we aimed to investigate the associations between subtle changes of LVEF and risk of common cardiovascular diseases. This is a prospective cohort study based on UK Biobank. LVEF was obtained from cardiac magnetic resonance. Incident cardiovascular disease was the outcome, including heart failure, atrial fibrillation, ischemic heart disease, and myocardial infarction. Cox proportional hazard model was the main method. A U-shaped relationship was observed between quantified LVEF and cardiovascular events risk with the nadir at the LVEF of 55-64%. As compared to moderate LVEF (55-64%), both low (40-54%) and high LVEF ( ≥ 5%) were related to higher risk of cardiovascular diseases after adjusting for confounders (HR = 1.15, 95%CI = 1.02-1.30; HR = 1.34, 95%CI = 1.05-1.72). Specifically, low LVEF was associated with increased risk of heart failure while high LVEF predominantly predicted elevated risk of ischemic heart diseases, both low and high LVEF were related to a borderline higher incidence of atrial fibrillation. Besides, associations with specific cardiovascular diseases varied by age, sex or comorbidities. There was a U-shaped relationship between LVEF and cardiovascular events risk with the nadir at the LVEF of 55-64%, while these associations were disease-specific and varied by age, sex or comorbidities.