The primary aim of the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) is to contrast the relative effectiveness of carotid artery stenting (CAS) versus carotid endarterectomy (CEA) in preventing stroke, myocardial infarction, and death. Stents are medical devices approved and commonly used for treatment of heart disease. The stent that will be used in this trial is the Rapid Exchange(RX) ACCULINK(TM) Carotid Stent System, an elastic-like metal scaffold that is expanded inside a carotid artery to hold the vessel open.