Value of Screening Asymptomatic Carotid Artery Stenosis Prior to Coronary Artery Bypass Grafting: Analysis of the E-CABG Registry

Background and aim: The aim of this study was to evaluate the prognostic impact of asymptomatic carotid artery stenosis(CAS) in patients undergoing isolated coronary artery bypass grafting(CABG). Methods:Patients from the multicenter, prospective E-CABG registry without history of stroke or transient ischemic attack and screened by duplex ultrasound for CAS before isolated CABG were included in this analysis. Results:Among 2813 patients screened by duplex ultrasound for asymptomatic CAS, 11.1% had a CAS of 50-59%, 6.0% of 60-69%, 3.1% of 70-79%, 1.4% of 80-89%, 0.5% of 90-99%, and 1.1% had carotid occlusion. Postoperative stroke occurred in 25 patients(0.9%). Lesions were bilateral in five patients(25%) and ipsilateral to a CAS ≥50% in six patients(30%). In univariate analysis, the severity of CAS was associated with a significantly increased risk of stroke(p<0.0001). In multivariate analysis, a CAS of 90-99%(OR 12.03, 95%CI 1.34-108.23) and the presence of an occluded internal carotid artery(OR 8.783, 95%CI 1.820-42.40) were independent predictors of stroke along with urgency of the procedure, severe-massive bleeding according to the E-CABG classification and the presence of a porcelain ascending aorta. Conclusions: Among patients with asymptomatic CAS, the risk of stroke is significant only in patients with a stenosis ≥90%. Since this condition has a low prevalence and when left untreated is associated with a relatively low rate of stroke, preoperative screening of asymptomatic CAS before CABG may not be justified. Instead, avoiding manipulation of diseased ascending aorta and prevention of excessive bleeding may be more effective measures to prevent stroke after CABG.