Indications for carotid screening in patients with coronary artery disease

We reviewed the literature about the usefulness of screening for carotid artery lesions in patients with coronary artery disease (CAD). The use of duplex ultrasonography to detect carotid lesions has a two-fold interest in this situation. First, it enables the detection of severe carotid artery stenosis (CS), a potentially reversible cause of stroke. Stroke is frequent in patients with CAD, accounting for at least in one-fourth of all cardiovascular events during follow-up. The mean prevalence of CS > 60% in patients with CAD is 9%, too low to justify routine carotid screening. However, older age, history of a cerebrovascular event, and peripheral arterial disease are useful factors for focusing screening on a high-risk subset of patients with CAD. Trials assessing the interest of prophylactic carotid surgery in asymptomatic CS of 60% or more found similar benefits in the subset of patients with CAD. Screening for CS in patients undergoing coronary artery bypass grafting is also important because CS is a marker, and sometimes the source, of perioperative stroke. Unfortunately, randomized studies to determine the best strategy in this situation are lacking. Second, while measurement of the carotid intima-media thickness does not provide substantial prognostic information for patients with CAD, the presence of plaque, especially hypoechogenic or echolucent (lipid-rich) plaque, is associated with an unstable or high-risk cardiovascular status. In this situation, specific studies are warranted to compare carotid imaging with biomarkers such as C-reactive protein and stratify the cardiovascular risk.