The utility of selective screening for carotid stenosis in cardiac surgerypatients

Purpose. To determine if any of 8 categorical clinical variables can be use d to select patients and improve the yield of a screening program for sever e carotid stenosis (greater than or equal to 80%) in elective cardiac surge ry patients. Methods. A prospective cohort analysis of 200 consecutive patients prior to elective cardiac surgery for the following variables: age, gender, smoking , carotid bruit, peripheral vascular disease, hyperlipidaemia, previous neu rologic symptoms and diabetes mellitus. All patients were subsequently scre ened with carotid duplex scanning for the presence of severe carotid stenos is. Positive scans were confirmed by angiography. Results. Sixteen patients (8%) were identified with severe carotid stenosis . Univariate analysis Identified three variables that increase risk for car otid stenosis: carotid bruit (relative risk(RR)=16.4, 5.4-57.6 95% confiden ce interval, p<0.001), neurological history (RR-10.3, 3.9-23.2, p<0.001) an d peripheral vascular disease (RR=5.3, 1.9-14.9, p<0.001). Stepwise logisti c regression analysis identified previous neurologic history and carotid br uit as independent predictors of stenosis. If screening for carotid stenosi s was limited to patients with these two variables, then 37 (18.5% of total ) patients would have been screened. Fourteen of these 37 (37.8%) had a sev ere carotid stenosis. Two patients with stenosis (12.5% of those with carot id stenosis, 1% of total patient population) would not have been screened. Conclusions. Clinical variables can be used to improve the yield of a preop erative screening program for carotid stenosis.