THE ROLE OF CAROTID SCREENING BEFORE CORONARY-ARTERY BYPASS

Five hundred thirty-nine patients with no symptoms of cerebral ischemia undergoing coronary artery bypass were preoperatively evaluated for presence of cartoid stenosis by noninvasive methods (duplex scanning and ocular pneumoplethysmography-Gee). Overall prevalence of carotid stenosis 〉 75% was higher (8.7%) than that generally reported. Age 〉 60 years was significantly related to presence of carotid stenosis 〉 75% (11.3% vs 3.8%,p = 0.003). Risk factors such as hypercholesterolemia, hypertension, diabetes mellitus, and smoking were not predictive for carotid stenosis, postoperative stroke, or death. Carotid stenosis 〉 75% (odds ratio 9.87, p < 0.005) and coronary artery bypass redo (odds ratio 5.26, p < 0.05) were both independent predictors of stroke risk. Patients were divided into four groups: group 1, minimal or mild degree of carotid stenosis (<50%), not submitted to prophylactic carotid endarterectomy (432 patients, 80.1%); group 2, moderate degree of stenosis (50% to 75%), no prophylactic carotid endarterectomy (60 patients, 11.2%); group 3, severe carotid stenosis; (〉75%), submitted to prophylactic carotid endarterectomy (19 patients, 3.5%), group 4, severe carotid stenosis (〉75%) no prophylactic carotid endarterectomy (28 patients, 5.2%). Patients in group 4 had significantly higher stroke rate (14.3%) compared to the other three groups (1.1%) (p = 0.0019). The finding of carotid stenosis greater than 75% in patients over 60 years of age was associated with occurrence of stroke in 15% of cases. Carotid screening is helpful to determine patients at increased risk of stroke and should be performed in patients 〉60 years. Although mechanism of stroke is unknown in patients with carotid stenosis, prophylactic carotid endarterectomy may reduce its occurrence (J VASC SURG 1990;12:724-31.) © 1990, Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter. All rights reserved.