The importance of prior stroke for the adjusted risk of neurologic injury after cardiac surgery for women and men

Background: Women arc at higher risk for stroke after cardiac surgery than men. Prior analysis of risk profiles for perioperative stroke that have mostly combined data from women and men may fail to identify gender-specific risks. The purpose of this study was to evaluate whether patient gender impacts adjusted risk for stroke after cardiac surgery. Methods. Demographic and perioperative data were prospectively collected from 2,972 patients undergoing cardiac surgery. Carotid artery ultrasound examination was performed before surgery for patients aged 65 yr or older or when there was a history of transient ischemic attacks or prior stroke. Epiaortic ultrasound was performed at the time of surgery in all patients to assess for atherosclerosis of the ascending aorta. Results: Strokes occurred after surgery in 30 women and 18 men (P < 0.0001). Based on multivariate logistic regression analysis, a history of a stroke was the strongest predictor of new stroke for both women and men. Low cardiac output syndrome, atherosclerosis of the ascending aorta, and diabetes mellitus were significantly associated with stroke for women but not for men. Analysis on the data from all patients using a gender-interaction term found that the risk for stroke associated with patient age, atherosclerosis of the aorta, diabetes, and duration of cardiopulmonary bypass was not affected by gender. The prior stroke-gender interaction, however, was significant (P = 0.017), suggesting that a prior cerebrovascular event was a more important predictor of stroke for men than women. Conclusions: These data show that prior stroke before surgery is strongly and independently associated with susceptibility for stroke after cardiac surgery, particularly for men. Other risk factors for perioperative stroke, though, do not appear to be influenced by patient gender.