PREDICTORS OF STROKE AFTER CARDIAC-SURGERY

From January 1, 1988 to September 30, 1993, 44 of 2,455 patients under going cardiac surgery for acquired heart disease at our institution su stained an intraoperative or postoperative cerebrovascular accident (C VA). Demographic data, atherosclerosis risk factors, past medical hist ory, cardiac catheterization reports, and intraoperative findings were retrospectively reviewed. The highest rate of CVA was in the sub-grou p of patients undergoing simultaneous myocardial revascularization and carotid endarterectomy (18.2%). The lowest rate was in a group of pat ients who underwent aortic valve replacement (0.9%). Severe aortic arc h atherosclerosis with the presence of atheromatous material or calcin osis at the cannulation site was identified intraoperatively in 43.2% of patients with neurological complications and in 5% of the group wit hout CVA (x(2) = 18.1, p = 0.0001). Of 44 patients with CVA, 13.6% had a history of preoperative completed stroke. CPB time was 90.1 +/- 4.9 min vs. 71.6 +/- 3.7 min (p = 0.004), and aortic cross-clamping time was 54.5 +/- 3.2 min compared to 39.8 +/- 2.7 min (p = = 0.001) in gro ups with and without postoperative stroke, respectively. Hypertension was an independent risk factor of postoperative CVA (x(2) = 9.5, p = 0 .02), but age was not. Neurological complications correlated with high operative mortality (38.6%) and prolonged postoperative hospital stay s (35.1 +/- 5.3). These data describe predictors for the development o f postcardiopulmonary bypass CVA and identify a high-risk subgroup for neurological events. The preoperative recognition of risk factors is an essential step toward the reduction of morbidity and mortality.