Low prevalence of significant carotid artery disease on ultrasound in patients proceeding to coronary artery bypass surgery

Background: Cardiothoracic surgery is associated with an increased risk of perioperative stroke. Preoperative carotid ultrasonography can identify significant stenosis, but there is debate about the value of screening. The aims of this study were to (i) determine the prevalence of significant carotid artery disease in screened patients undergoing cardiothoracic surgery and (ii) correlate their ultrasonographic findings with perioperative strokes. Methods: Retrospective analysis of 166 patients (118 men, 48 women) who underwent a preoperative carotid ultrasound and coronary artery bypass graft surgery (CABG) from 2004 to 2007. Perioperative strokes were recorded and compared with ultrasonographic and clinical data. A separate cohort of 1423 patients (1064 men, 359 women) who underwent CABG over the same period was also evaluated. Results: Only 11 screened patients (6.6%) had significant (>70%) carotid artery disease and two of these underwent simultaneous carotid endarterectomy. There were five perioperative strokes in screened patients, four of which occurred in individuals with <50% disease. Compared with the non-screened cohort, ultrasound screened patients were older and more likely to have a prior stroke or transient ischaemic attack, hypertension, hypercholesterolaemia, peripheral vascular disease and/or renal impairment than non-screened patients. There was no significant difference in perioperative strokes compared with non-screened patients (3% vs 1.2% respectively, P = NS). Conclusion: There is a low prevalence of significant carotid artery disease in ultrasound screened patients. The risk of perioperative strokes in screened patients is low and not significantly different from non-screened patients.