Sex differences in long-term survival after total arterial coronary artery bypass grafting

OBJECTIVES: It is uncertain if the evidence on improved long-term survival of total arterial coronary artery bypass grafting applies to female patients. This study aims to compare the long-term survival outcomes of using total arterial revascularization (TAR) versus at least 1 saphenous vein graft separately for men and women. METHODS: This retrospective analysis of the Australian and New Zealand Society of Cardiac-Thoracic Surgical Database had administrative linkage to the National Death Index. We identified all patients undergoing primary isolated coronary bypass from June 2001 to January 2020 inclusive. Following sex stratification, propensity score matching with 36 variables and Cox proportional hazard regression were used to facilitate adjusted comparisons. A Cox interaction-term analysis was performed to investigate the impact of sex on TAR survival benefit. The primary outcome was all-cause mortality. RESULTS: Of the 69 624 eligible patients receiving at least 2 grafts, 13 019 (18.7%) were female patients. Matching generated 14 951 male and 3530 female pairs. Compared to vein-dependent procedures, TAR was associated with significantly reduced incidence of long-term all-cause mortality for both male (hazard ratio, 0.86; 95% confidence interval, 0.81-0.91; P < 0.001) and female (hazard ratio, 0.82; 95% confidence interval, 0.73-0.91; P < 0.001) cohorts. Interaction-term analysis indicated no significant subgroup effect from sex (P = 0.573) on the survival advantage of TAR. The treatment effect provided by TAR remained significant across most sex-stratified disease subgroups. CONCLUSIONS: TAR, when compared to the use of at least 1 saphenous vein graft, provides comparable superior long-term survival outcomes in both females and males.