CAROTID-ARTERY DUPLEX SCANNING IN PREOPERATIVE ASSESSMENT FOR CORONARY-ARTERY REVASCULARIZATION - THE ASSOCIATION BETWEEN PERIPHERAL VASCULAR-DISEASE, CAROTID-ARTERY STENOSIS, AND STROKE

Purpose: The purpose of this study was to identify high-risk populatio ns for severe carotid artery disease (SCD) and neurologic events (NE) after nonemergency isolated coronary artery bypass graft procedures (C ABG). Methods: Between February 1989 and July 1992, 387 patients under went preoperative carotid artery duplex scanning as part of a preopera tive assessment for nonemergency cardiac procedures. Of these patients , 376 had isolated CABG, and 11 had combined carotid endarterectomy (C EA) and CABG. Patient demographics, risk factors, and preoperative neu rologic symptoms were recorded and analyzed. Severe carotid artery dis ease was defined as a 80% or greater stenosis of either internal carot id artery by carotid artery duplex scanning. Patients were evaluated f or neurologic events (cerebrovascular accident, transient ischemic att ack, amaurosis fugax, or reversible ischemic neurologic deficits) duri ng the in-hospital postoperative period. Results: The prevalence of SC D was 8.5% (33 patients). The 33 patients with SCD were significantly older (65.6 +/- 6.5 years vs 62.5 +/- 10.4 years,p = 0.02), had previo us CEA (27.3% vs 2.0%, p = 0.00001), had preoperative neurologic sympt oms (21.2% vs 5.9%, p = 0.002), and had peripheral vascular disease (P VD) (63.6% vs 16.9%, p = 0.00001). The sensitivity of PVD for SCD is 6 3.6% (n = 21/33) (specificity 83.1%, positive predictive value 25.9%, negative predictive value 96.1%). In patients undergoing CABG alone, t hose who had postoperative NE were older (69.6 +/- 6.7 years vs 62.5 /- 10.3 years, p = 0.036) and more likely to have PVD (50% vs 19.7%, p = 0.034), SCD (40% vs 4.9%, p = 0.001) and previous CEA (40% vs 2.7%, p = 0.0002). The incidence of postoperative NE in patients with SCD w as 18.2% vs 1.7% in patients without SCD (p = 0.001). The sensitivity of SCD for NE was 40% (n = 4/10) (specificity 95.1%, positive predicti ve value 18.2%, negative predictive value 98.3%). Conclusions: PVD may be helpful to identify patients at high risk for severe carotid arter y stenosis. Postoperative NE in patients with CABG are associated with increasing age, carotid artery stenosis greater than 80%, previous CE A, and PVD.