In the past 2 decades, 2 large multicenter trials have demonstrated the efficacy of carotid endarterectomy (CEA) for patients with asymptomatic carotid stenosis: the Asymptomatic Carotid Atherosclerosis Study (ACAS) and the Asymptomatic Carotid Surgery Trial (ACST).1,2 These trials found that CEA, compared with best medical therapy, was associated with a significant relative risk reduction of 50% during 5 years but only an absolute reduction in ipsilateral stroke of 0.5% to 1% per year. With the number needed to treat to prevent 1 stroke in 1 year approaching 100 to 200, whether this degree of stroke reduction is clinically significant has been debated.3 The trials have led to evidence-based recommendations supporting CEA for selected patients with asymptomatic carotid stenosis and a surge in carotid revascularization procedures in recent years. Among Medicare patients in the period 2004-2006, 87% of carotid artery stenting (CAS) and 88% of CEA procedures were performed in asymptomatic patients.4