CREST-2: Identifying the Best Method of Stroke Prevention for Carotid Artery Stenosis: National Institute of Neurological Disorders and Stroke Organizational Update

One of the great achievements of modern medicine is the successful prevention of stroke and other cardiovascular diseases. Although the incidence of stroke has substantially declined over the last 30 years, ≈200 000 preventable stroke deaths still occur annually in the United States. According to a recent study based on the Greater Cincinnati/Northern Kentucky Stroke Study, annually ≈41 000 strokes in the United States are attributed to extracranial internal carotid artery stenosis. Early revascularization for symptomatic carotid stenosis—that is, in patients with recent ipsilateral stroke or TIA—is well established as effective at preventing ipsilateral stroke. Carotid stenosis in the absence of symptoms is extremely common, but the best treatment is unclear. While 2 randomized trials showed a benefit of carotid endarterectomy (CEA) over antiplatelet therapy with aspirin, the number needed to treat approaches 200. Does aggressive risk factor control change that balance? Population screening for carotid stenosis followed by revascularization is considered to cause net harm. Are complication rates from endarterectomy and stenting now low enough to justify expanding their indications in asymptomatic patients? The National Institute of Neurological Disorders and Stroke (NINDS)–funded CREST-2 trial (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial) is an ambitious attempt to further refine the treatment of asymptomatic carotid stenosis. As one of the largest randomized stroke prevention trials, the first CREST (Carotid Revascularization Endarterectomy Versus Stenting Trial) was designed to compare the safety and efficacy of 2 stroke prevention procedures for carotid artery narrowing—CEA and carotid artery stenting (CAS)—in symptomatic and asymptomatic individuals. Starting in December 2000, this NINDS-funded trial enrolled >2500 patients at 117 sites in the United States and Canada. Because of slow enrollment, the trial took 9 years to complete. In 2010, the results of CREST indicated that the 2 revascularization procedures were equivalent for …