Gender influence on cognitive function after cardiac operation

Background. Women are at higher risk than men for stroke after cardiac operation. The purpose of this study was to evaluate for gender influences on the more common postoperative neurologic complication, cognitive dysfunction. Methods. A standard battery of neuropsychological tests was administered to 117 patients (79 men and 38 women) the day before and again 4 to 6 weeks after cardiac operation. The battery assessed a broad array of cognitive domains, including attention, memory, executive function, and psychomotor processing speed. Analysis was performed only on patients with data from both testing sessions. Data were analyzed to assess for a dichotomous definition of postoperative cognitive impairment and to evaluate for factors influencing test results for specific cognitive domains. Results. The frequency of one standard deviation decline on two or more cognitive tests compared with preoperative results (women, 10.7% versus men, 9.9%; p = 0.527), no decline, or one standard deviation improvement on each test postoperatively was no different between genders. After adjusting for age, gender, preexisting medical conditions, level of attained education, preoperative cognitive tests results, type of operation, and duration of cardiopulmonary bypass, female gender was independently associated with poorer performance postoperatively on visuospatial tasks. Other variables significantly related to postoperative cognitive function varied among the specific cognitive domains. Conclusions. These data suggest that, although the frequency of cognitive dysfunction after cardiac operation is similar for women and men, women appear more likely to suffer injury to brain areas subserving visuo-spatial processing. Risk factors for postoperative cognitive impairment vary depending on cognitive domain, suggesting multiple etiologies for this form of perioperative neurologic injury.