CAPITAL: Carotid Artery Plaque Intravascular Ultrasound Evaluation

Inclusion Criteria:

• >18 years of age
• Patient must be:

Symptomatic with lesions >/= to 50% stenosis, or Asymptomatic with lesions of >/= to 75% stenosis in at least one carotid artery, specific to the internal carotid artery, common carotid artery or bifurcated region; documented through acceptable ultrasound studies, completed within 30 days of recruitment.

• For patients with bilateral carotid disease- procedures need to be staged greater than 30 days apart. The lesion that has a greater degree of stenosis will be considered as the index procedure.
• Women of childbearing potential must have a negative pregnancy test within 7 days prior to treatment.
• The patient is able to give informed consent.

Exclusion Criteria:

• The patient is experiencing a new (acute) neurologic event or has experienced a stroke within the last 30 days prior to enrollment.
• The patient has intracranial tumors, arterial vascular malformations >5mm, aneurysms or severe intracranial stenosis distal to the target lesion.
• Presence of thrombus at the target site or loose 'floating' debris as determined by duplex analysis and/or angiography.
• Existing hemorrhagic disease or coagulation problems creating inability to obtain homeostasis at entry site.
• The patient has an allergy to, or is unable to tolerate, heparin, concomitant medications (clopidogrel or ticlid, aspirin) or to nitinol metal.
• The patient has a history of or known reaction to radiocontrast agent (radiopaque dye) and is unable to be premedicated.
• Coumadin treatment that has continued during the 48 hours prior to enrollment and an INR above hospital normals (i.e. in the event of atrial fibrillation or prosthetic valve replacement).
• Hemodynamic instability at the time of intervention.
• Severe chronic renal insufficiency (plasma/ serum creatinine> 2.5 mg/dL) at the time of intervention, except in patients on dialysis.