Carotid Revascularization Endarterectomy Versus Stenting Trial
Carotid Revascularization Endarterectomy Versus Stenting Trial
The purpose of the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) is
 to compare the relatively new procedure of stent-assisted carotid angioplasty (CAS) to the
 traditional and accepted surgical approach of carotid endarterectomy (CEA) for the treatment
 of carotid artery stenosis to prevent recurrent strokes in those patients who have had a TIA
 (transient ischemic attack) or a mild stroke within the past 6 months (symptomatic) and in
 those patients who have not had any symptoms within the past 6 months (asymptomatic).
The primary aim of the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST)
 is to contrast the relative effectiveness of carotid artery stenting (CAS) versus carotid
 endarterectomy (CEA) in preventing stroke, myocardial infarction, and death. Stents are
 medical devices approved and commonly used for treatment of heart disease. The stent that
 will be used in this trial is the Rapid Exchange(RX) ACCULINK(TM) Carotid Stent System, an
 elastic-like metal scaffold that is expanded inside a carotid artery to hold the vessel open.

 The RX ACCUNET(TM) Embolic Protection System (an umbrella-like device that expands above the
 narrowed portion of the carotid artery) will be used in conjunction with the RX ACCULINK
 stent. The RX ACCUNET system is designed to capture embolic material that could break off
 from the narrowed area in the carotid artery while still allowing blood to flow through the
 vessel during the procedure. Embolic material could block blood flow to the arteries beyond
 the narrowing and be harmful to the brain. The RX ACCUNET System is closed and removed after
 the stent is placed.

 CEA involves a neck incision and physical removal of the plaque from the inside of the
 artery. CAS involves insertion of a catheter or tube into an artery in the groin and then
 threading the catheter through the arteries of the body to the location of the plaque within
 the carotid artery in the neck. The stent is then placed to cover the plaque and hold the
 artery open. Participants will be randomly assigned to undergo either CAS or CEA, and all
 patients will receive best medical management, which includes treatment with aspirin,
 treatment of high blood pressure, and treatment of other stroke risk factors. Participants
 will be followed for up to ten years.

 With the simplification of the protocol for long-term follow-up, the focus for secondary
 outcomes is to assess restenosis and viability of the procedure. Restenosis rates on an
 annual basis in both the endarterectomy and stenting arms of the study will be assessed using
 carotid duplex ultrasound exams performed annually (standard of care).

 In addition to restenosis, the "viability" of the procedures will be assessed by the need (or
 lack of need) for repeat revascularization (either open surgical or endovascular) after the
 index procedure. The question "has a new carotid intervention been performed since last
 follow-up" will be asked at every contact with the patient. If answered positively,
 additional data will be collected on the appropriate case report forms(CRFs).

 LINKAGE OF CREST COHORT WITH CENTERS FOR MEDICAID AND MEDICARE SERVICES(CMS) ADMINISTRATIVE
 DATA

 The purpose of linking Medicare-eligible CREST participants with CMS data files is to assess
 patient outcomes and utilization of health care services. This plan to link in- and
 out-patient episodes of care using national Medicare data establishes a new resource that
 will enhance current follow-up strategies, as well as explore alternative strategies to
 ascertain patient outcomes for future clinical studies.
Inclusion Criteria:

 -  Symptomatic patients with recent neurological events (TIA or non-disabling stroke)
 with an associated carotid stenosis greater than or equal to 50% by angiography or
 greater than or equal to 70% by ultrasound or greater than or equal to 70% by Computed
 Tomography Angiography (CTA) or Magnetic Resonance Angiography (MRA) are eligible for
 randomization.

 -  Asymptomatic patients with no recent (in the last 6 months) neurological events
 referable to the study with artery and carotid stenosis (patients with symptoms beyond
 180 days are considered asymptomatic) greater than or equal to 60% by angiography or
 greater than or equal to 70% by ultrasound or greater than or equal to 80% by CTA or
 MRA are eligible for randomization.

 Exclusion Criteria:

 -  Conditions that: (1) interfere with the evaluation of endpoints, (2) are known to
 interfere with the completion of CEA or CAS, or (3) affect the likelihood of survival
 for the study period (4 years). Chronic atrial fibrillation and/or anti-coagulation or
 episodic atrial fibrillation within the last 6 months.