Abstract 4141689: Sex-based Differences of Inpatient Mortality Following Coronary Artery Bypass Grafting: Insight From Large National Database

Background: Female patients referred for coronary artery bypass grafting (CABG) are generally older and have more comorbidities than their male counterparts. Although higher perioperative mortality among female patients has been reported, there is a lack of large-scale, real-life data on this outcome and its trend. Aim: To study the mortality rate among female patients undergoing CABG from 2015-2020 and compare it with that of their male counterparts. Methods: The National Inpatient Sample from January 2015 to December 2020 was utilized to identify the study population using the International Classification of Diseases, Ninth and Tenth Revisions, Clinical Modification. The primary outcome was the overall in-hospital mortality of CABG based on sex, and the secondary outcome was the mortality trend between the groups. Results: We evaluated 929,759 patients who underwent CABG, of whom 230,000 (24.3%) were female. The female patient group was slightly older than the male patient group (66.4 vs 65.4 years, P<.001) and had a lower proportion of Caucasians (73.7% vs 79.4%, P<.001). Overall mortality among the female patients was nearly double that of their male counterparts (2.5% vs 1.4%, P<.001). Over the study period, the adjusted mortality rate declined in both sexes but remained higher in the female group (Fig. 1A). Among female patients, the mortality rate decreased from 2.5% in 2015 to 1.6% in 2019 (P<.001), then increased to 2.0% in 2020 (P=.050). The mortality rate among male patients consistently declined, from 1.9% in 2015 to 1.2% in 2020 (P<.001). Conclusion: This analysis reveals that female patients undergoing CABG have higher mortality rates than their male counterparts despite overall declines in mortality rates over the study period. The persistent disparity and the observed increase in mortality in female patients in 2020 highlight the need for further research to identify and address the precipitating factors of this outcome.