National Heart Lung and Blood Insitute (NIH) [Public domain] via Wikimedia CommonsThe Centers for Medicare and Medicaid Services (CMS) are considering an expansion of coverage for carotid angioplasty and stenting (CAS) with embolic protection to include, among other groups, patients at high risk for the surgical alternative (carotid endarterectomy, CEA) who have asymptomatic carotid stenosis of at least 80%. A key consideration that will drive this discussion centers on the currently available data supporting the benefits of CAS, the natural history of stroke risk in asymptomatic patients, and the relative merits of CEA and medical therapy in this subgroup.