Why Are the Results of Coronary Artery Bypass Grafting in Women Worse?

A study was conducted to assess the early results of isolated coronary artery bypass grafting in women and to determine the risk factors for early postoperative complications. Between January 1994 and July 2001, 1,730 patients (301 women and 1,429 men) underwent isolated myocardial revascularization. Conventional bypass procedure was performed on 1,554 patients (270 female and 1,284 male) and off-pump procedure on 176 patients (31 female and 145 male). Hospital mortality was significantly higher in women than in men (5.6% versus 2.9%). Low cardiac output syndrome developed in 8.6% of women and 8.5% of men. Postoperative myocardial infarction occurred in 5.3% of women and 4.3% of men (p < 0.05). The rate of infectious complications was significantly higher in women (7.0%) than in men (5.8%). The independent risk factors for early mortality in women were left ventricular ejection fraction below 40%, left main disease, and urgent operation. The need for urgent surgery in women was also found to be a significant independent predictor of low cardiac output syndrome and postoperative myocardial infarction. In conclusion, higher hospital mortality and morbidity in women undergoing coronary surgery are partially related to the severity of coronary atherosclerosis and comorbid conditions.