Carotid artery stenting (CAS) is less invasive and has a lower incidence of systemic complications such as myocardial infarction compared with carotid endarterectomy. Clopidogrel Resistance and Embolism in Carotid Artery Stenting (CRECAS) The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Patients with symptomatic or asymptomatic carotid stenosis in whom carotid artery stenting is planned are randomised between antiplatelet therapy with ticagrelor plus aspirin or clopidogrel plus aspirin and examined with brain MRI before and after stent treatment. In carotid stenting, a long, hollow tube (catheter) is threaded through the arteries to the narrowed carotid artery in the neck. A metal mesh tube (stent) is inserted into the vessel to serve as a scaffold that helps prevent the artery from narrowing again. The catheter and the filter — which catches any debris that may break off during the procedure — are removed. The CYP2C19 gene plays a detrimental role in the metabolism of clopidogrel. This study aimed to investigate the association between CYP2C19 polymorphisms and the clinical efficacy of clopidogrel therapy in patients who have undergone carotid artery stenting (CAS). Dual antiplatelet therapy (DAPT) using acetylsalicylic acid (ASA, 75-325 mg daily) associated with a thienopyridine (either clopidogrel 75 mg daily or ticlopidine 250 mg twice a day) is strongly recommended by the international guidelines for patients undergoing carotid artery stenting (CAS) to reduce perioperative neurologic events. Antiplatelet Therapy in Carotid Artery Stenting and Carotid Endarterectomy in the Asymptomatic Carotid Surgery Trial-2 Author links open overlay panel A. Huibers a c A. Halliday a R. Bulbulia b G. Coppi d G.J. de Borst c ACST-2 Collaborative Group Carotid artery stenting is being used as an alternative to carotid endarterectomy, both within the context of clinical trials and in non-surgical candidates. Antiplatelet Therapy in Carotid Artery Stenting and Carotid Endarterectomy in the Asymptomatic Carotid Surgery Trial-2 A. Huibers a,c, A. Halliday a,*, R. Bulbulia b, G. Coppi d, G.J. de Borst c, on behalf of the ACST-2 Collaborative Group Carotid artery stenting (CAS) is a minimally invasive technique for treating carotid artery disease. Carotid endarterectomy (CEA) has been shown to reduce the incidence of stroke in patients with symptomatic and asymptomatic carotid stenosis.