Background: Extracranial internal carotid artery stenosis is a risk factor for perioperative stroke in coronary artery bypass (CAB) surgery. Although both selective and nonselective methods of preoperative carotid screening have been advocated, it is unclear which approach is most clinically efficacious.
Methods: Hospital records for 1421 consecutive CAB patients from January 2000 through April 2002 were reviewed. Univariate and multivariate analyses were performed across selected parameters to identify risk factors for significant carotid stenosis (> or = 70%). Patients were retrospectively stratified into high- or low-risk groups based on risk factors common to carotid stenosis and perioperative stroke. The prevalence of carotid stenosis, surgical management, and perioperative stroke rates were determined for each group.
Results: One-thousand one-hundred thirty-eight patients out of 1421 patients (80.1%) underwent preoperative carotid screening. The prevalence of significant carotid stenosis was 13.4%. Univariate risk factors for stenosis included an age of more than 65 years, peripheral vascular disease, prior cerebrovascular accident, history of cerebrovascular disease, left main coronary disease, carotid bruit, female gender, and hypertension. Carotid stenosis was a risk factor for stroke, neurologic injury, in-hospital mortality, and longer hospitalization. Prevalence of carotid stenosis was greater in high-risk patients (17.8%, N = 708) versus low-risk patients (6.1%, N = 426). Concomitant or staged carotid endarterectomy (CEA)/CAB was more commonly performed in the high-risk group (5.8% vs. 1%, p < 0.001). All nine patients with significant carotid stenosis who suffered perioperative strokes were in the high-risk group (9 out of 708 vs 0 out of 426, p = 0.016).
Conclusions: In our cohort, selectively screening only patients with either an age of more than 65, carotid bruit, or cerebrovascular disease would have reduced the screening load by nearly 40% with negligible impact on surgical management or neurologic outcomes.