Early hospital readmission after coronary artery bypass grafting in men and women: a retrospective cohort study

Background Early hospital readmission after coronary artery bypass grafting (CABG) is a relevant quality and prognostic indicator, reflecting baseline patient characteristics as well as procedural complexity and the clinical course during initial hospitalization. Sex-related differences have been reported in postoperative outcomes; however, their independent contribution to early readmission remains uncertain. Purpose To compare baseline characteristics and postoperative mortality between men and women undergoing CABG and to identify factors independently associated with hospital readmission at 30, 60, and 90 days. Methods In this retrospective observational cohort, 1,548 consecutive patients undergoing CABG were included, of whom 1,122 were men. Baseline characteristics were compared between sexes using the Mann–Whitney test. Postoperative mortality was assessed using the chi-square or Fisher’s exact test, as appropriate. Hospital readmission within 30, 60, and 90 days after discharge was evaluated using univariate and multivariate logistic regression models adjusted for sex, age, length of hospital stay, length of intensive care unit (ICU) stay, and use of cardiopulmonary bypass (CPB). Statistical significance was defined as p<0.05. Results Women underwent CABG at an older age than men (64.0±9.4 vs. 62.9±9.5 years; p=0.012) and had longer hospital stays (27.2±21.1 vs. 21.3±15.9 days; p<0.001) and ICU stays (6.9±8.5 vs. 5.5±6.9 days; p<0.001). Left ventricular ejection fraction was higher in women both preoperatively (54.5±12.0 vs. 52.1±13.2%; p=0.002) and postoperatively (56.5±11.2 vs. 53.7±12.3%; p<0.001). Overall postoperative mortality was approximately 4%, numerically higher in women (5.2% vs. 3.5%), without statistically significant difference. In univariate analysis, length of hospital stay and CPB use were associated with readmission at 30, 60, and 90 days (p<0.001). In multivariate models, length of hospital stay remained the strongest independent predictor of readmission across all time points (p<0.001), along with CPB use (p<0.01), whereas sex, age, and ICU stay were not independently associated. Conclusion Despite relevant sex-related differences in baseline characteristics and postoperative course, early hospital readmission after CABG was primarily driven by factors reflecting procedural complexity and the clinical course during initial hospitalization. Length of hospital stay and CPB use emerged as the main independent determinants of short- and mid-term readmission.