Is sex a factor in determining operative risk for aortocoronary bypass graft surgery?

This study examines trends and sex differences in characteristics of patients referred for bypass graft surgery to identify factors associated with operative morbidity and mortality.

Data were collected prospectively on consecutive patients (1132 men and 355 women). Over time, the proportion of patients > 65 years old, with diabetes, or requiring urgent surgery, increased. Predictors of mortality were age > 75 years, urgent surgery, and poor left ventricular (LV) grade. Women were older (62 +/- 9 versus 59 +/- 9 years, P < .001) and had more varicose veins (18% versus 7%, P < .001), diabetes (27% versus 18%, P < .001), hypertension (48% versus 41%, P < .05), peripheral vascular disease (16% versus 12%, P < .05), and more severe angina (P < .001). There were no sex differences in prior myocardial infarction (59% versus 62%) or need for urgent surgery (17% versus 18%). Women had a higher ejection fraction (51% +/- 12% versus 47% +/- 14%, P < .001) and fewer diseased vessels (2.4 +/- 0.7 versus 2.6 +/- 0.6, P < .001) and received fewer grafts (2.9 +/- 0.9 versus 3.3 +/- 0.8, P < .001). Women had smaller body size but were no more likely to have small target vessels (< 1.5 mm). There was no sex difference in operative mortality (1.4% versus 1.1%), perioperative myocardial infarction (4.8% versus 3.5%), need for intra-aortic balloon pump (10% versus 8%), stroke (1.7% versus 1.4%), reexploration for bleeding (1.7% versus 1.7%), or leg infection (2.0% versus 1.4%). Women had fewer sternal wound infections (0.6% versus 2.2%, P < .05).

Predictors of mortality include advanced age, decreased LV function, and need for urgent surgery. With time, despite increasing age, associated diabetes, and increased urgent surgery, operative mortality has decreased. Women were older and had more diabetes and hypertension but less extensive disease and better LV function. Bypass graft surgery was associated with equally low mortality in women and men (1.4% versus 1.1%). Concern over increased operative mortality in women should not bias referral patterns for angiography and coronary bypass graft surgery.