Israeli women were at a higher risk than men for mortality following coronary bypass surgery

Abstract

As part of a national study of surgical departments in Israel, cardiac surgery patients undergoing open heart surgery between 1987 and 1989 were followed-up prospectively. Of these, 1,046 patients had coronary artery bypass grafting (CABG) and are the subject of this report. The six-months mortality after surgery was 12.9% among 202 women and 4.1% among 844 men. Female gender was an independent predictor of mortality even after controlling for the effect of 14 putative risk factors. The adjusted relative risk for mortality in women compared to men was 2.79 (1.5–5.2). In an attempt to understand this excessive mortality among women, a detailed analysis in one of the participating hospitals revealed differences associated with surgical technique by gender, such as proportion of patients with entirely venous grafting vs internal mammary artery grafts (IMA). Thirty percent of women vs 4.8% of men had entirely venous grafting. Adjusting the data for differences in the proportion of venous grafting has obliterated the difference in mortality between the genders in that hospital. We suggest that interventions to reduce mortality among women should involve a more careful choice of female candidates for CABG surgery, as well as introduction of modifications in the operating technique.