Predictors of adverse neurological outcome following cardiac surgery

Abstract

Introduction: Stroke is a debilitating complication of cardiac surgery. Many intraoperative and postoperative factors predict the likelihood of post-cardiac surgery stroke. We evaluated preoperative parameters, seeking correlations with adverse neurological outcome following cardiac surgery. We investigated the possibility of preoperative carotid ultrasonography to select patients for carotid endarterectomy pre- or intraoperatively. Methods: We conducted a retrospective analysis of 61 patients who suffered stroke post-cardiac surgery from 2003 to 2006. Data was collected for patient and disease characteristics, preoperative status, intraoperative events and postoperative course. Postoperative neurological complications were subdivided into three groups: mild/temporary events, moderate events such as seizures, and severe events such as stroke. A mild/temporary event was defined as a focal neurological deficit of less than 24 hours in duration. Results: A total of 2,226 cardiac cases were retrospectively evaluated. The frequency of stroke was 61 patients (2.7 percent). The mean age of these patients was 63.7 +/- 7.4 years, and 40 (65.6 percent) were males. Logistic EuroSCORE, left ventricular ejection fraction (as determined by two-dimensional echocardiogram) and aortic cross-clamp time were significantly correlated with postoperative neurological complications, with a p-value of less than 0.05 for all subgroups. There was a significant correlation between the presence of preoperative carotid disease (as proven by pre- and postoperative carotid ultrasonography) and postoperative neurological events (p-value equals 0.033). However, atrial fibrillation did not correlate with postoperative stroke. Conclusion: The stage of cardiac disease (risk factor level, ejection fraction and presence of carotid stenosis) correlates with stroke and may predict an adverse neurological outcome.