PRELIMINARY-REPORT OF A GENETIC-BASIS FOR COGNITIVE DECLINE AFTER CARDIAC OPERATIONS

Background. Changes in memory and cognition frequently follow cardiac operations. We hypothesized that patients with the apolipoprotein E-ep silon 4 allele are genetically predisposed to cognitive dysfunction af ter cardiac operations. Methods. The apolipoprotein E-epsilon 4 allele was evaluated as a predictor variable for postoperative cognitive dys function in 65 patients undergoing cardiac bypass grafting at Duke Uni versity Medical Center. The primary outcome measure was performance on a cognitive battery administered preoperatively and at 6 weeks postop eratively. Results. In a multivariable logistic regression analysis in cluding apolipoprotein E-epsilon 4, preoperative score, age, and years of education, a significant association was found between apolipoprot ein E-epsilon 4 and change in cognitive test score in measures of shor t-term memory at 6 weeks postoperatively. Patients with lower educatio nal levels were more likely to show a decline in cognitive function as sociated with the apolipoprotein E-epsilon 4 allele. Conclusions. This study suggests that apolipoprotein E genotype is related to cognitive dysfunction after cardiopulmonary bypass. Cardiac surgical patients m ay be susceptible to deterioration after physiologic stress as a resul t of impaired genetically determined neuronal mechanisms of maintenanc e and repair. (C) 1997 by The Society of Thoracic Surgeons.