The Carotid Revascularization Endarterectomy vs. Stenting Trial completes randomization: Lessons learned and anticipated results

The Carotid Revascularization Endarterectomy vs. Stenting Trial (CREST) completed randomization on July 18, 2008. Sponsored by the National Institute of Neurological Disorders and Stroke (NINDS), the trial has enrolled 2,522 participants across North America and is the largest randomized clinical trial (RCT) comparing the efficacy of carotid artery stenting (CAS) to carotid endarterectomy (CEA). It is also the largest RCT to assess carotid revascularization in both symptomatic and asymptomatic patients with carotid artery stenosis. Conventional-risk patients with symptomatic carotid stenosis (≥50% by angiography, ≥70% by ultrasound) or asymptomatic carotid stenosis (≥60% by angiography, ≥70% by ultrasound) were randomized to both treatment arms in a 1:1 ratio. Eligibility criteria for CREST were similar to those of the previous NINDS-sponsored CEA RCTs. The investigational devices used in the CAS arm of the study are the RX Acculink stent and the RX Accunet embolic protection system, (Abbott Vascular, Santa Clara, Calif). The primary aim is to contrast the efficacy of CAS versus CEA in preventing stroke, myocardial infarction, and all-cause mortality during a 30-day peri-procedural period, and ipsilateral stroke over the follow-up period (extending up to four years). The secondary aims are to contrast the efficacy of CAS and CEA in men and women, the restenosis rates of the two procedures, health-related quality of life, and cost effectiveness of CAS and CEA. The conclusion of enrollment in CREST marks the end of a long recruitment period from 117 community and academic hospital centers across the United States and Canada. Each surgeon and interventionalist underwent a rigorous credentialing process that included performance-assessment of prior CEA and CAS procedures. Credentialing of interventionalists also included a review of additional CAS procedures enrolled into a CREST lead-in phase prior to entering patients into the randomized trial; 1564 patients were enrolled in the lead-in, the final pathway for the largest credentialing effort to date for any clinical trial. CREST will provide long-term follow-up after carotid revascularization based on systematic ultrasonographic and neurologic surveillance, and on quality of life and cost-effectiveness comparisons between CAS and CEA in the setting of a RCT. We present a brief description of the CREST protocol, impediments that were overcome during the trial, salient results from the lead-in phase of the trial, a summary of enrollment activities and characteristics of the final cohort, and a timeline for anticipated results from the randomized phase.