Atherosclerotic Peripheral Vascular Disease Symposium II

Carotid artery disease is a major cause of ischemic stroke, the risk of which is directly related to the severity of stenosis and presence of symptoms.1,2 Stroke is the third leading cause of death in the United States, with approximately three quarters of a million strokes per year. Stroke is the leading cause of functional impairment, with more than 20% of survivors requiring institutional care and up to one third having a permanent disability.3 More worrisome, however, is the fact that as the population ages, the number of patients having strokes appears to be increasing.4 The pathophysiology of stroke may be broadly classified as hemorrhagic, embolic, or ischemic. The majority of strokes are caused by embolic events due to atheroemboli from the carotid artery, the ascending aorta, and arch vessels or cardiac thromboembolism from the left atrium or ventricle. It is estimated that carotid artery stenosis is responsible for 15% to 20% of all strokes.5 As percutaneous treatment options expand, there is uncertainty about appropriate therapy for carotid disease. This document will focus on 3 current controversies: (1) carotid artery revascularization in asymptomatic patients, (2) carotid artery stenting (CAS) in patients who are considered to be at increased surgical risk for carotid endarterectomy (CEA), and (3) the current role for CAS in patients at average surgical risk. ### Prevalence and Natural History The prevalence of asymptomatic extracranial carotid stenosis (≥50%) in persons >65 years of age is estimated to be between 5% and 10%, whereas ≤1% of patients are estimated to have a severe narrowing (>80%).6 In asymptomatic patients with ≥50% carotid artery stenoses, the annual risk of stroke is between 1% and 4.3%.2,7 Long-term (10- to 15-year) cohort studies in asymptomatic patients with moderate to severe carotid stenosis demonstrate an ipsilateral stroke rate between 0.9% and 1.1% per …