Multiple arterial vs. single arterial coronary artery bypass grafting: sex-related differences in outcomes.

Background And Aims: Uncertainty exists over whether multiple arterial grafting has a sex-related association with survival after coronary artery bypass grafting. This study aims to compare the long-term survival of using multiple arterial grafting vs. single arterial grafting in women and men undergoing coronary artery bypass grafting.

Methods: The retrospective study used the Australian and New Zealand Society of Cardiothoracic Surgical Database with linkage to the National Death Index. Patients from 2001 to 2020 were identified. Sex-stratified, inverse probability weighted Cox proportional hazard model was used to facilitate survival comparisons. The primary outcome was all-cause mortality.

Results: A total number of 54 275 adult patients receiving at least two grafts in primary isolated bypass operations were analysed. The entire study cohort consisted of 10 693 (19.7%) female patients and 29 711 (54.7%) multiple arterial grafting procedures. At a median (interquartile range) postoperative follow-up of 4.9 (2.3-8.4) years, mortality was significantly lower in male patients undergoing multiarterial than single arterial procedures (adjusted hazard ratio 0.82; 95% confidence interval 0.77-0.87; P < .001). The survival benefit was also significant for females (adjusted hazard ratio 0.83; 95% confidence interval 0.76-0.91; P < .001) at a median (interquartile range) follow-up of 5.2 (2.4-8.7) years. The interaction model from Cox regression suggested insignificant subgroup effect from sex (P = .08) on the observed survival advantage. The survival benefits associated with multiple arterial grafting were consistent across all sex-stratified subgroups except for female patients with left main coronary disease.

Conclusions: Compared to single arterial grafting, multiple arterial revascularization is associated with improved long-term survival for women as well as men.