A combined analysis of these trials found the greatest benefit for CEA was in severe (70% 99%) ICA stenosis with recent symptoms. Post hoc analysis of these original trials found a greater benefit of CEA when the surgery was done in patients who were enrolled within 2 weeks of their last ischemic event. These trials were initiated >30 years ago, and current optimal medi- cal therapy was not used in these trials. There is a paucity of data on CEA compared with current optimal medical therapy in patients with symptomatic carotid stenosis. CEA also has been compared with CAS. Across several trials, CAS was associated with a higher periprocedural stroke rate, but similar results have been seen with CEA and CAS beyond the immediate periprocedural period. Extracranial-to-intracranial bypass for internal carotid occlusion has not been demonstrated to reduce the risk of recurrent stroke. Recommendation-Specific Supportive Text 1. A combined analysis by Rothwell et al369 of the original CEA trials (NASCET [North American Symptomatic Carotid Endarterectomy Trial], ECST [European Carotid Surgery Trial], and VA [Veterans Affairs Trial 309]) found robust benefit for CEA in patients with severe (70% 99%) ICA stenosis (16.0% absolute benefit over 5 years). In these studies, patients were typically >40 years of age and of either sex. The NASCET method of stenosis measurement was used in the combined analysis of the 3 trials. In the original trials (NASCET and ECST), angiography was used for stenosis mea- surements, but more recent trials (CREST [Carotid Revascularization Endarterectomy versus Stenting Trial]) and routine clinical practice typically use noninvasive imaging, with angiography used for cases with discrepant or ambiguous results from noninvasive tests. 2. Surgical results and statistical modeling from clini- cal trials such as NASCET and CREST support this threshold for perioperative outcomes.24 3. 