Boston Scientific Embolic Protection, Inc. (EPI): A Carotid Stenting Trial for High-Risk Surgical Patients (BEACH)

Key General Inclusion Criteria: * Patient must meet criteria for either A or B: A. Symptomatic: Carotid stenosis of greater than or equal to 50% via angiography with associated cerebral or retinal TIA or ischemic stroke symptoms within 180 days of the procedure, which are determined to have occurred in the cerebral hemisphere or eye ipsilateral to the target carotid artery lesion and to be reasonably attributable to that lesion; or B. Asymptomatic: Carotid stenosis greater than or equal to 80% via angiography without associated cerebral or retinal TIA or ischemic stroke symptoms within 180 days of the procedure. * Target lesion is in the native common carotid artery (CCA), internal carotid artery (ICA), or carotid bifurcation. * Target arterial segment to be stented has a diameter of greater than or equal to 4.0 mm to less than or equal to 9.0 mm. * Vessel diameter distal to the target lesion is greater than or equal to 3.5 mm and less than or equal to 5.5 mm as an optimal "landing zone" for placement of the FilterWire EZ System with visual angiographic recommendations as described in the instructions for use (IFU). Key High-Risk Eligibility Inclusion Criteria: * Patients must qualify in at least one high-risk category. The high-risk categories are defined as: * Anatomical conditions \[one (1) criterion qualifies\] * Co-morbid conditions Class I \[one (1) criterion qualifies\] * Co-morbid conditions Class II \[two (2) criteria qualify\] Exclusion Criteria: * Patient has experienced an evolving, acute, or recent stroke within 21 days of study evaluation. * A total occlusion of the ipsilateral carotid artery. (Only for Roll-In and Pivotal patients.) * A total occlusion of the contralateral carotid artery. (Only for Bilateral Registry patients.) * Pre-existing stent(s): * Roll-In and Pivotal Patients: located within the ipsilateral carotid distribution; a stent was placed in a contralateral vessel within the previous 30 days of the study enrollment. * Bilateral Registry Patients: located within the carotid distribution. * A target lesion which is expected to require more than one stent. * Known cardiac sources of emboli of a type likely to be associated with cerebral ischemic events \[e.g. endocarditis, intracardiac thrombus, embolic-associated cardiovascular lesions, or any current arrhythmia (e.g. atrial fibrillation, atrial flutter, etc.)\]. * Myocardial infarction (MI) within 72 hours prior to the index procedure, defined as creatine kinase (CK)-MB \> 2 X the local laboratory's upper limit of normal (ULN). * Any surgery requiring general anesthesia (e.g. coronary artery bypass graft \[CABG\], valve replacement, or abdominal aortic aneurysm) less than or equal to 30 days preceding the stent procedure. * The patient is enrolled in another investigational study protocol and has not completed the required follow-up period of the evaluation. The patient may not participate in another investigational study that may confound the treatment or outcomes of the BEACH protocol.