Magnetic resonance imaging findings and postoperative neurologic dysfunction in elderly patients undergoing coronary artery bypass grafting

Background. Small cerebral infarctions are common in elderly patients, but the association between the magnetic resonance imaging finding and neurologic dysfunction after coronary artery bypass grafting has not been evaluated. Methods. We determined, prospectively, whether varying degrees of abnormal findings on magnetic resonance images of the brain increased the incidence of preoperative cognitive decline, postoperative neuropsychological dysfunction, and stroke in 421 elderly patients (≥ 60 years) undergoing coronary artery bypass grafting. Results. Control patients (almost normal or leukoaraiosis, N = 212) had rates of postoperative neuropsychological dysfunction (7%) and stroke (1.4%); the small infarctions group (some small infarctions, N = 126) had rates of 13% and 5.6%, respectively; whereas patients with multiple infarctions (multiple small infarctions or broad infarctions, N = 83) had rates of 20% and 8.4%, respectively (p = 0.004, p = 0.013). In the group with multiple infarctions, 49 patients (59%) were asymptomatic and 21 patients (25%) had cognitive decline. Stepwise logistic regression analysis demonstrated that the significant predictors of multiple small infarctions or large infarctions were history of cerebrovascular disease, renal insufficiency, cognitive decline, and cerebral arteriosclerosis. Conclusions. Multiple infarctions significantly increase the risk of neurologic dysfunction after coronary artery bypass grafting. Routine screening for preoperative cognitive decline should be performed to detect underlying ischemic cerebral disease in elderly patients.