Association of ejection fraction with mortality and cardiovascular events in patients with coronary artery disease

Abstract

Aims: Recent studies suggested that both left ventricular ejection fraction (LVEF) lower than 60% or higher than 65% were associated with an increased mortality in the general population. Uncertainty remains regarding adverse outcomes across LVEF in coronary artery disease (CAD). The common understanding was that LVEF <40% was associated with an increased risk of mortality. But the threshold at LVEF of 40% was arbitrary because quite a lot of adverse outcomes existed in patients with ejection fraction >40%. We aimed to evaluate the relationship between LVEF and mortality or adverse events in CAD patients undergoing percutaneous coronary intervention (PCI). Methods and results: A total of 10 252 CAD patients undergoing PCI from an observational cohort were studied. All-cause mortality and major adverse cardiovascular and cerebrovascular events (MACCE) were set as outcomes. Kaplan–Meier curves, adjusted Cox regression models, and restricted cubic spline analyses were used for evaluation. A total of 137 (1.3%) patients had all-cause mortality, and 816 (8.0%) patients had MACCE during a median of 2.4 years of follow-up. The median LVEF was 64%. All-cause mortality and MACCE rates changed substantially across LVEF categories, and a linear inverse relationship of LVEF with all-cause mortality and MACCE risk was observed. All-cause mortality or MACCE risk increased significantly below an LVEF of 55 or 65%, respectively. Patients with LVEF <55% had a more than 3.5-fold higher mortality than those with LVEF ≥55%. Patients with LVEF <65% had a more than 1.3-fold higher MACCE than those with LVEF ≥65%. Below 55 or 65%, there was a rise in mortality or MACCE. A gradient–response relationship was observed, with an all-cause mortality risk range between 8.6-fold and 3.0-fold increase from LVEF <40 to 50–54.9% and MACCE risk range between 2.4-fold and 1.4-fold from LVEF <40 to 60–64.9%. Conclusions: In CAD patients undergoing PCI, LVEF lower than 55% or LVEF lower than 65% was correlated with increased all-cause mortality and MACCE respectively, whereas higher LVEF was not.