Trends in Sex-based Differences in Outcomes Following Coronary Artery Bypass Grafting in the United States Between 2004 and 2015

Background: The present study sought to examine the trends of sex-based differences in clinical outcomes after coronary artery bypass grafting (CABG), an area in which the current evidence remains limited.

Methods: All US adults hospitalized for first-time isolated CABG in the National Inpatient Sample database between 2004 and 2015 were included, stratified by sex. Multivariable regression analysis examined the adjusted odds ratios (OR) of postoperative in-hospital complications in females versus males. Trend analyses of sex-based differences in in-hospital post-operative complications over the study period were performed.

Results: Overall, 2,537,767 CABG procedures were analyzed, including 27.9% (n = 708,459) females. Female sex was associated with an increase in adjusted odds of all-cause mortality (OR 1.43 95% CI 1.40, 1.45), stroke (OR 1.34 95% CI 1.32, 1.37) and thoracic complications (OR 1.28 95% CI 1.27, 1.29) and lower odds of all-cause bleeding (OR 0.87 95% CI 0.86, 0.89) compared to males. Trend analysis revealed these sex differences to be persistent for mortality, stroke and thoracic complications (p = non-significant) but eliminated for bleeding over the study period (p < 0.001).

Conclusion: Despite technical advances over the 12-year period, worse post-operative outcomes including death, stroke, and thoracic complications have persisted in female patients after CABG. These findings are concerning and underscore the need for risk reduction strategies to address this disparity gap.