Impact of gender on mid-term prognosis of patients undergoing coronary artery bypass grafting

OBJECTIVES: We evaluated the impact of sex on mid-term prognosis in patients who underwent coronary artery bypass grafting (CABG). Data on gender differences in current management or clinical outcomes after CABG are controversial, and there have been limited data focusing on them. METHODS: This was a retrospective and prospective, single-center, observational study. Between January 2001 and December 2017, 6613 patients who underwent CABG were enrolled from an institutional registry of Samsung Medical Center, Seoul, Korea (Clinicaltrials.gov, NCT03870815) and divided into two groups according to sex (female group, n = 1679 vs. male group, n = 4934). The primary outcome was cardiovascular death or myocardial infarction (MI) at 5 years. Propensity score matching analysis was performed to reduce confounding factors. RESULTS: During a mean follow-up duration of 54 months, a total of 252 cardiovascular death or MIs occurred (female, 78 [7.5%] vs. male, 174 [5.7%]). Multivariate analysis revealed no significant difference in the incidence of cardiovascular death or MI at 5 years between female and male groups (hazard ratio [HR] 1.05; 95% confidence interval [CI] 0.78 to 1.41; p = 0.735). After propensity score matching, the incidence of cardiovascular death or MI was still similar between the two groups (HR 1.08; 95% CI 0.76 to 1.54; p = 0.666). The similarity of long-term outcomes between the two groups was consistent across various subgroups. There was also no significant difference in the risk of 5-year cardiovascular death or MI between males and females according to age (pre- and postmenopausal status) (p for interaction = 0.437). CONCLUSIONS: After adjusting for baseline differences, sex does not appear to influence long-term risk of cardiovascular death or MI in patients undergoing CABG. CLINICAL TRIALS.GOV NUMBER: NCT03870815.