The association between left ventricular ejection fraction and long-term survival: a large hospital-based cohort study in taiwan

Abstract

Abstract Background Left ventricular ejection fraction (LVEF) is the most commonly used metric for quantifying left ventricular function. A U-shaped relationship between LVEF and long-term survival with a nadir between 60-70% has been reported in the western, regardless of age, sex, or prevalent heart failure. However, the distribution of mortality risk across the spectrum of LVEF among Asian population remains unclear. Purpose We aim to investigate the distribution of mortality risk across the spectrum of LVEF among Asian population, as well as among different subgroups. Methods In this large hospital-based cohort study, consecutive participants who underwent echocardiography (2002-2021) in a tertiary medical center in Taiwan were included. LVEF was measured by echocardiography using biplane Simpson’s method. All LVEFs were categorized into intervals of 5% from <20% to ≥70%. The National Death Registry was linked to identify mortality and causes of death. Cox proportional hazards regression was used for analyses with adjustment for age, sex, body mass index, and comorbidities. Results A total of 142,834 participants (age 60.6 ± 18.4, men 50.5%) were included. During a mean follow-up of 58.1 ± 47.1 months, 17,317 subjects (12.1%) died. Overall, adjusted hazard ratios (HR) for all-cause mortality showed a U-shaped relationship between LVEF and long-term survival with a nadir of risk at LVEF of 60-70%. Compared with the reference group (LVEF: 60-65%), subjects with LVEF> 70% had a HR of 1.21 (95% confidence interval [CI]: 1.12-1.30) and those with LVEF of 50-55% had a HR of 1.28 (95% CI: 1.22-1.35). (Figure) Similar results with a nadir at 60-70% could also be observed when stratified by the age of 65, sex, comorbidities of hypertension, or diabetes. Conclusions A U-shaped relationship between LVEF and long-term survival with a nadir at LVEF of 60-70% can also be observed in the Asian population. This result may support the use of LVEF> 70% to define supranormal LVEF in Asian subjects.Figure