Abstract
BACKGROUND: The effect of coronary artery bypass grafting (CABG) on cardiac function improvement remains controversial. Furthermore, recent evidence suggests that improvement in cardiac function after CABG does not improve life expectancy. This study aimed to examine whether CABG improved cardiac function and how this improvement influenced all-cause mortality and to compare patient prognosis according to preoperative cardiac function. METHODS: This retrospective study included patients with a left ventricular ejection fraction (LVEF) of ≤35% who underwent CABG between January 1994 and December 2022. We compared patients with and without cardiac function improvement, defined as an increase in LVEF of ≥10%, to identify associated factors and assess the impact on all-cause mortality. We also compared outcomes according to the degree of preoperative LV dysfunction. RESULTS: Among the 166 patients included, 102 and 64 had a preoperative LVEF of 25%-35% and ≤25%, respectively. The mean follow-up duration was 79.9 ± 72.3 months. We observed significant LVEF improvement, from 28% (range, 23.3%-35%) preoperatively to 39% (range, 31%-46%) at 13.1 months postoperatively. The 7-year survival rates were similar in the ejection fraction ≤25% and 25%-35% groups (80.2% vs 73.8%, P = .11). However, patients with an LVEF improvement of ≥10% exhibited a markedly better prognosis than those without LVEF improvement at 7 years (85.9% vs 63.5%, P=.001). CONCLUSIONS: Our findings suggest that CABG may enhance cardiac function in more than half of patients with ischemic cardiomyopathy, with a correlation to improved all-cause mortality. Moreover, LVEF improvement after CABG is associated with an improved prognosis.