Long-term mortality after coronary surgery in women patients depend on diabetes and age

There is general consensus of the higher short-term risk in women after coronary artery bypass grafts (CABG), nonetheless, long-term survival is a matter of debate. We aimed to compare in a national database with over 10 years of follow-up long-term survival in women versus men and its interaction with diabetes and age.

This is a national retrospective cohort study from Uruguay. Patients were included if they underwent isolated CABG between 1 January 2002 and 31 December 2022. The primary outcome was survival. The secondary outcome was a composite of operative mortality, postoperative stroke, deep sternal wound infection and kidney failure requiring dialysis. Interaction of age and diabetes was explored in the survival analysis after adjusting for baseline characteristics.

During the included study period, 21 959 patients (5778 were women) underwent isolated CABG in Uruguay. Among people with diabetes, women had worse survival, while no differences between gender were found in the non-diabetic population. Survival at 1 year after CABG was significantly lower in women (hazard ratio (HR) = 1.20; 95% confidence interval (CI): 1.07, 1.35; P = 0.002). Survival after 1-year was higher in women (P < 0.001). Absence of diabetes improved survival (HR = 0.83; 95% CI: 0.77, 0.89; P < 0.001), while presence of diabetes made survival between men and women similar (HR = 1.00; 95% CI: 0.92, 1.09; P = 0.946). Interaction between age and gender showed that women older than 60 years old had better survival than men. Composite outcome was worse in women (OR = 1.47; 95% CI: 1.24, 1.75).

Women patients have worse overall mortality but better long-term survival than men. Diabetes and age have significant interaction with the long-term outcomes. Better survival is seen in women older than 60 years old.