Abstract 9278: No Improvement in the Operative Outcomes of Women Undergoing Coronary Artery Bypass Surgery in the United States, 2011-2020

Background: Women undergoing coronary artery bypass grafting (CABG) have significantly higher mortality and morbidity compared to men. While on a national level overall mortality after CABG has significantly decreased over the last decade, it is unclear if this trend of improvement applies to women. Objective: The aim of this analysis was to evaluate trends in outcomes of women undergoing CABG in the United States over the course of the last decade. Methods: The data for this study was provided through the STS Participant User File research program. Patients were included in the analysis if they underwent primary isolated CABG during the study period. Patients requiring resuscitation prior to surgery, emergent/salvage operations, and reoperation were excluded. The primary outcome was operative (30-day) mortality. The secondary outcome was the composite of operative mortality and morbidity (including operative mortality, stroke, renal failure, reoperation, deep sternal wound infection, prolonged mechanical ventilation, prolonged hospital stay). For all the outcomes, the STS definitions were used. The attributable risk (the effect of female sex on CABG outcomes) for the primary and secondary outcomes was calculated. Results: Between 2011 and 2020, 1,297,204 patients underwent multivessel CABG, 317,716 (24.5%) of which were women. The proportion of women decreased from 26.2% in 2011 to 22.7% in 2020 (P for trend <0.001). Women had a higher unadjusted operative mortality (2.8% vs 1.7%, P <0.001) and overall unadjusted incidence of the composite of operative mortality and morbidity (22.9% vs 16.7%, P <0.001) compared to men. The attributable risk of female sex for operative mortality varied from 1.28 in 2011 to 1.41 in 2020, with no significant change over the study period (P for trend=0.37). The attributable risk for the composite of operative mortality and morbidity was 1.08 in 2011 and 2020, with no significant change over the study period (P for trend=0.71). Conclusion: Female sex remains an independent risk factor for adverse outcomes following CABG and no significant improvement has been seen over the course of the last decade. Further investigation into the determinants of operative outcomes in women is urgently needed.