Do women benefit more than men from off-pump coronary artery bypass grafting?

Objectives Outcomes after coronary artery bypass grafting (CABG) are worse in women than in men. This study aims to investigate whether off-pump coronary artery bypass (OPCAB) surgery improves the outcomes in women by comparing different outcome measures in both genders. Methods Patients who underwent isolated CABG, either on-pump (ONCAB) or OPCAB, between January 1998 and June 2017 were included. Primary endpoints were 30-day and 120-day mortality. Logistic regression models were constructed to evaluate the effect of the CABG technique on important outcomes such as mortality and the need for blood transfusion. Results The data of 17,052 patients were analysed, 3,684 of whom were women (414 OPCAB) and 13,368 men (1,483 OPCAB). The mean number of grafts was lower in the OPCAB group of both genders (p<0.001). Postoperatively, both men and women undergoing OPCAB surgery received fewer red blood cell transfusions (p<0.001) and had higher postoperative haemoglobin levels (p<0.001) than those undergoing ONCAB. Early mortality occurred less frequently after OPCAB surgery in both genders, although the difference was not significant. However, 120-day mortality was significantly lower after OPCAB surgery in women, even after correction for preoperative risk factors [odds ratio (OR)=0.356, 95% confidence interval (CI) 0.144-0.882, p=0.026]. The difference in 120-day mortality was not significant in men (OR=0.787, 95% CI 0.498-1.246, p=0.307). Conclusions Women undergoing CABG benefit more from OPCAB surgery than from ONCAB surgery in terms of 120-day mortality. This difference was not found in men in our patient population.