Characteristics of cerebrovascular accidents after coronary artery bypass grafting

Abstract

The records of all patients who had a cerebrovascular accident (CVA) following coronary artery bypass surgery were reviewed to determine the incidence, etiology, and outcome following such an event. Between January 1, 1987, and December 31, 1990, 3,428 patients underwent bypass grafting and 46 had a CVA, documented by head computed tomography (CT) after neurologic findings were appreciated, for an incidence of 1.3 per cent. In 16 patients, a neurologic deficit was documented less than 12 hours after surgery and was presumed to have been an intraoperative event. The remaining 30 patients became symptomatic between postoperative days 2 and 7. Twenty-five patients (54%) exhibited neurologic and CT findings suggestive of an embolic event, while the remaining 21 patients appeared to have sustained an infarct as a result of cerebral hypoperfusion. Nine patients with CVA had a carotid bruit documented in the preoperative period, and seven of these suffered their ischemic event in the ipsilateral distribution. Five patients had a documented CVA previously, and four were shown to have extended areas of previous infarction. The mortality following CVA was 35 per cent. Of the survivors, 70 per cent had some improvement in symptoms at the time of discharge; 60 per cent of survivors were discharged to their homes and the remainder to extended care facilities. Although CVA following coronary bypass grafting is an uncommon event, some patients at increased risk may benefit from more aggressive preoperative noninvasive evaluation and intraoperative monitoring. A better understanding of the etiology of postoperative stroke may help to prevent its high morbidity and mortality, which has been demonstrated.