title: The influence of gender on the outcome of coronary artery bypass surgery.
abstract: BACKGROUND
  To assess the impact of gender as an independent risk factor for early and late morbidity and mortality following coronary artery bypass surgery.
  
  
  METHODS
  Perioperative and long-term data on all 4,823 patients undergoing isolated coronary bypass operations from November 1989 to July 1998 were analyzed. Of these patients, 932 (19.3%) were females.
  
  
  RESULTS
  During the years 1989 to 1998 there was a progressive increase in the percentage of women undergoing coronary artery bypass surgery. The following preoperative risk factors were more prevalent among women than men: age above 70, angina class 3 or 4, urgent operation, preoperative intraaortic balloon pump usage, congestive heart failure, previous percutaneous transluminal coronary angioplasty, diabetes, hypertension, and peripheral vascular disease (all p < 0.05). Men were more likely to have an ejection fraction less than 35%, three-vessel disease, repeat operations, and a recent history of smoking. Women had a statistically significant smaller mean body surface area than men (1.72+/-0.18 versus 1.96%+/-0.26% m2). On average, women had fewer bypass grafts constructed than men (2.9%+/-0.8% versus 3.2%+/-0.9%) and were less likely to have internal mammary artery grafting (76.2% versus 86.1%), multiple arterial conduits (10.1% versus 19.8%), or coronary endarterectomy performed (4.9% versus 8.6%). The early mortality rate in women was 2.7% versus 1.8% in men (p = 0.09). Women were more prone to perioperative myocardial infarction (4.5% versus 3.1% p < 0.05). After adjustment for other risk variables, female gender was not an independent predictor of early mortality but was a weak independent predictor for the prespecified composite endpoint of death, perioperative myocardial infarction, intraaortic balloon counterpulsation pump insertion, or stroke (8.55 versus 5.9%; odds ratio, 1.30; 95% confidence interval, 0.99 to 1.68; p = 0.05) Recurrent angina class 3 or 4 was more frequent in female patients (15.2%+/-4.0% versus 8.5%+/-2.0% at 60 months, p = 0.001) but not repeat revascularization procedures (percutaneous transluminal coronary angioplasty, redo) (0.6%+/-0.3% versus 4.1%+/-0.8% at 60 months). Actuarial survival at 60 months was greater in women then men (93.1%+/-1.7% versus 90.0%+/-1.0%), and after adjustment for other risk variables, female gender was protective for late survival (risk ratio, 0.40; 95% confidence interval, 0.16-0.74; p < 0.005).
  
  
  CONCLUSIONS
  Perioperative complications were increased and recurrent angina more frequent in women. Despite this, late survival was increased in women compared with men after adjustment for other risk variables
authors.affiliation: Division of Cardiovascular Surgery, Sunnybrook and Women's College Health Sciences Center, University of Toronto, Ontario, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Abramov
authors.forename: M G
authors.initials: MG
authors.lastname: Tamariz
authors.forename: J Y
authors.initials: JY
authors.lastname: Sever
authors.forename: G T
authors.initials: GT
authors.lastname: Christakis
authors.forename: G
authors.initials: G
authors.lastname: Bhatnagar
authors.forename: A L
authors.initials: AL
authors.lastname: Heenan
authors.forename: B S
authors.initials: BS
authors.lastname: Goldman
authors.forename: S E
authors.initials: SE
authors.lastname: Fremes
mesh_terms: D000367:Age Factors; D000368:Aged; D000787:Angina Pectoris / Q000150:complications; D015906:Angioplasty, Balloon, Coronary; D001830:Body Surface Area; D001026:Coronary Artery Bypass / Q000401:mortality; D048909:Diabetes Complications; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012307:Risk Factors; D012737:Sex Factors; D015996:Survival Rate; D016896:Treatment Outcome; D014652:Vascular Diseases / Q000150:complications