History of Changes for Study: NCT02240862
The CREST-2 Companion Registry (C2R)
Latest version (submitted July 19, 2022) on
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Study Record Versions
Version A B Submitted Date Changes
1 September 12, 2014 None (earliest Version on record)
2 October 9, 2014 Study Status, Eligibility and Study Description
3 February 6, 2015 Recruitment Status, Study Status and Contacts/Locations
4 June 25, 2015 Recruitment Status, Contacts/Locations, Sponsor/Collaborators, Study Status, Groups and Interventions, Study Identification, Study Description, References, Eligibility, Conditions and Oversight
5 November 4, 2015 Contacts/Locations and Study Status
6 May 17, 2016 Study Status
7 April 13, 2017 Study Status, Contacts/Locations, Eligibility, Study Description, Oversight and Study Identification
8 September 7, 2017 Study Status and Eligibility
9 March 20, 2018 Study Status
10 September 6, 2018 Study Status
11 February 12, 2019 Study Status
12 October 16, 2019 Sponsor/Collaborators, Study Status and Contacts/Locations
13 December 11, 2019 Study Status and Study Design
14 March 31, 2020 Study Status and Contacts/Locations
15 July 16, 2021 Study Status
16 July 19, 2022 Contacts/Locations and Study Status
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Study NCT02240862
Submitted Date:  September 12, 2014 (v1)

Open or close this module Study Identification
Unique Protocol ID: C2R
Brief Title: The CREST-2 Companion Registry (C2R)
Official Title: The CREST-2 Companion Registry
Secondary IDs:
Open or close this module Study Status
Record Verification: September 2014
Overall Status: Not yet recruiting
Study Start: October 2014
Primary Completion: October 2021 [Anticipated]
Study Completion:
First Submitted: September 12, 2014
First Submitted that
Met QC Criteria:
September 12, 2014
First Posted: September 16, 2014 [Estimate]
Last Update Submitted that
Met QC Criteria:
September 12, 2014
Last Update Posted: September 16, 2014 [Estimate]
Open or close this module Sponsor/Collaborators
Sponsor: Mayo Clinic
Responsible Party: Principal Investigator
Investigator: Thomas G. Brott, M.D.
Official Title: PI
Affiliation: Mayo Clinic
Collaborators: National Institute of Neurological Disorders and Stroke (NINDS)
Centers for Medicare and Medicaid Services
University of Maryland
Society for Vascular Surgery
American College of Cardiology
Open or close this module Oversight
U.S. FDA-regulated Drug:
U.S. FDA-regulated Device:
Data Monitoring:
Open or close this module Study Description
Brief Summary: The objective of the CREST-2 Registry is to promote the rapid initiation and completion of enrollment in the CREST-2 randomized clinical trial ( ID NCT02089217). Patients with severe symptomatic and asymptomatic carotid artery occlusive disease will be treated with carotid artery stenting performed by adequately experienced and skilled interventionists. Interventionists' eligibility will be determined by the multi-specialty CREST-2 Interventional Management Committee. Patient eligibility will include patients with conventional or high risk, symptomatic and asymptomatic carotid artery disease. Patients will be followed for the occurrence of post-complications. The primary safety and quality endpoint will be the occurrence of any stroke or death within the 30-day period following the stenting procedure. The individual interventionist safety and quality results from the CREST-2 Registry will help guide selection of interventionists for participation in the CREST-2 randomized clinical trial. Enrollment into the CREST-2 Registry will begin in 2014 and continue until publication of the primary results from the CREST-2 randomized clinical trial.
Detailed Description:

This description provides the framework for the companion registry to accompany the CREST-2 trial ( NCT02089217) .


  1. The C2R CAS Registry will promote rapid initiation and completion of enrollment in the CREST-2 trial
  2. CAS will be performed by adequately experienced operators within the trial and the registry
  3. Clinical outcomes of trial and registry patients will be closely monitored
  4. The framework is designed to prevent inappropriate use of CAS outside of the trial and the registry
  5. Patient periprocedural outcomes (i.e. patient safety) are equally important in registries and in randomized clinical trials. Final decisions will be taken in light of the paramount importance of patient outcomes and benefit.

    Registry Data Collection:

    The registry will leverage existing data-collection infrastructure, the Society of Vascular Surgery's (SVS) Vascular Quality Initiative (VQI) and the American College of Cardiology's (ACC) National Cardiovascular Data Registry (NCDR), and will harmonize a core, research quality group of data fields to be collected. This effort has involved collaboration with their respective (and other) professional societies and both organizations have agreed to participate in this effort. The specific logistics of data-collection and transfer are:

    • The interventionist must pick a registry, SVS VQI or ACC NCDR.
    • Each then notifies that registry in writing that any cases they submit that are intended for the C2R, and CMS reimbursement, should be submitted to the C2R.
    • The C2R cases are reviewed by the Chair of the C2R Management Team and the CREST-2 Team.
    • Reports of the cases, including whether or not they are CREST eligible, will be maintained so the spreadsheet will always have data on individuals as the data are reviewed by the C2R (this may be in bunches of ~ 5 cases or so); these reports will allow close monitoring of registry interventionists and registry sites.
    • Official reports to the C2R Management Team, the Steering Committee, and other parties (NINDS, CMS) can be prepared biannually.

    The final mechanisms through which this will be accomplished are being finalized. These may need to be modified to some degree based on technical and policy limitations of those systems. Operational responsibility for managing all aspects of the registry will be carried out under the existing CREST-2 management structures, but with separate, dedicated oversight. The type of data to be collected is focused on the following:

    The registry will collect information on key co-morbidities to stratify risk and limit the outcome measures to essential, easily used standardized measures that are commonly part of stenting trials, including the NIH Stroke Scale and the Modified Rankin Scale (mRS). The 30-day visit will be conducted face-to-face with a history, examination and testing. The 1-year visit will be completed via telephone to minimize patient burden. The co-morbidities that will be collected at baseline include all the elements necessary to stratify risk using the published technique used in ECST-2 [Rothwell PM]. The NIH Stroke Scale will be performed by certified personnel other than the operator pre- and post-procedure.

    • DEMOGRAPHICS AND MEDICAL HISTORY: Gender, Symptomatic Status, Carotid Artery to be Treated, Hypertension, Plaque morphology, Diabetes, Myocardial Infarction, Brain Imaging Reports for Patients with a Neurological Event, TIA, New Seizure, Intracranial Hemorrhage, Hyper-perfusion Syndrome, Congestive Heart Failure, New Requirement for Dialysis, Infection
    • PATIENT ASSESSMENT, IMAGING AND OUTCOMES: NIH Stroke Scale, Modified Rankin, Access Site Hemorrhage Requiring Transfusion or Surgery, Recurrent Hospitalization or Need for Second Carotid Procedure, New Onset of Renal Failure Requiring Dialysis, Imaging (e.g. Duplex Ultrasound) to Evaluate Stent Patency, Patient Reported Outcomes (instruments TBD), Stroke, Death

    The Registry will also collect information on features that represent inclusion/exclusion criteria for the CREST-2 randomized trial. The purpose is to facilitate monitoring of the type of patients being enrolled in the Registry, and ensuring that CREST-2-eligible patients are not being enrolled excessively into the Registry once CREST-2 credentialing has been achieved. The limits for Registry enrollment are discussed in detail in the sections below. Data-collection, transfer and review will occur rapidly enough that sites not complying with enrollment limitations will be identified rapidly and appropriate action taken. Reports on characteristics of patients enrolled by individual interventionists at each site will be prepared to monitor enrollment at a specific and granular level.

    The CREST-2 Companion Registry focuses on procedural details that will facilitate an assessment for credentialing interventionists into the CREST-2 trial. The interventional management committee of CREST-2 will review this data to make decisions regarding whether or not to approve a particular operator for randomizing patients into the trial.

    • Total number of cases performed per year, total number of cases performed in career, selection of devices, case selection, stroke rate, hemorrhagic complications.
    • Techniques for access, sheath placement, wire access, embolic protection, angioplasty, stent deployment, use of post-stent angioplasty, selection of closure devices, use of medications (antiplatelets, anticoagulation, atropine, nitroglycerine).

    Eligibility to participate in the C2R


    • Any center currently certified by CMS to provide CAS will be eligible to apply for participation in the C2R. These centers must explicitly state their intent to enroll patients in CREST-2 once they have met the minimum volume requirements for the trial.
    • Any center applying for participation in the C2R must apply for certification through either ACE or IAC.


    • Individual operators must have done at least 50 total procedures to be eligible for the registry. If they have done less than 50 procedures, then they must have done at least 8 procedures over the last 2 years.
    • Individual operators must have been reviewed and approved by the CREST-2 IMC. Regardless of the number of individual interventionists at a center, each participating center will be subject to the overall enrollment restriction of 1:1 in the registry versus CREST-2.
    • The number of procedures required to be performed in the registry prior to achieving credentialing to randomize patients in the CREST-2 trial will vary according to the volume of experience of individual operators and their outcomes (to be determined by the CREST-2 IMC).

    Procedures to ensure enrollment into the randomized trial

    • The maximal lead in number for the C2R for a given site prior to randomization into CREST-2 will be a total of 75 cases or 30 CREST-2 eligible patients, whichever comes first. Sites that have credentialed, IMC-initiated, operators will be expected to enroll eligible patients into the randomized trial prior to reaching this threshold. Operators that have been credentialed by the IMC to enroll patients in CREST-2 must begin to enroll eligible patients in the trial, while other operators at the same site continue to work toward credentialed status. Sites that have reached the maximum thresholds above and are not initiated as CREST-2 sites will have registry status denied at the discretion of the C2R steering committee depending on bona fide, good faith efforts to meet CREST-2 site initiation requirements.
    • The C2R will track whether or not each patient enrolled in the registry was CREST-2 eligible. Once any operator at a site has been approved to enroll patients in CREST-2, the site will be expected to offer enrollment into CREST- 2 to every CREST-2 eligible patient. It is anticipated that not all such CREST-2 eligible patients will consent to randomization into CREST-2; such patients, those who decline consent, can be enrolled into the registry. However, only one such CREST-2 eligible patient can be enrolled into the registry for each patient enrolled into CREST-2, i.e. in a 1:1 ratio. Patients that are not eligible for CREST-2 are not subject to this requirement (though the site remains obligated to the requirement that the maximal lead in number prior to randomization into CREST-2 will be a total of 75 cases or 30 CREST-2 eligible patients, whichever comes first). Sites that do not maintain the 1:1 ratio of patients enrolled in CREST-2 to trial-eligible patients enrolled in the C2R will be notified by the C2R Steering Committee that they are on a 30 day probationary status to remedy the situation. If not remedied, they will be notified that their C2R status is being revoked.
    • Centers/operators that have begun to enroll patients in CREST-2 must enroll all additional CAS patients in the CREST-2 trial unless they are not eligible for the trial, they decline to participate, or until the CAS arm of CREST-2 is fully enrolled. Those CREST-2 eligible patients who decline enrollment into CREST-2 can be enrolled into the registry in a 1:1 ratio (see above bullet point). Physicians who are cleared for randomization in CREST-2 may not enroll CREST-2 eligible patients in the registry unless the patient declines participation in CREST-2 (and the 1:1 ratio is being met at the site as defined above), until the CAS arm of the trial is fully enrolled. Any asymptomatic patient who is enrolled in the registry by a physician cleared for randomization must have the CREST-2 exclusion criterion clearly documented.
    • Sites that are not enrolling into CREST-2 at a reasonable rate (to be determined by the C2R Steering Committee and the CREST-2 Executive Committee) will have their eligibility to enroll in the C2R suspended until they are adequately enrolling in the trial.
    • Once the CAS arm of CREST-2 is fully enrolled, continued enrollment of eligible patients (see inclusion/exclusion criteria above) in the C2R will be allowed.
    • The DSMB will review CREST-2 trial results at end of enrollment of the CREST-2 trial to decide at that time if it is ethical to continue the CREST-2 Companion Registry.

    Registry Oversight / Governance

    The C2R will be operated under a multi-specialty Steering Committee. The Steering Committee will include members from relevant disciplines. Representatives from the Mayo Clinic, NINDS, and CMS will be nonvoting ex-officio members of the Steering Committee. The Steering Committee shall provide strategic direction to the C2R, monitor all activities, and have ultimate authority and responsibility for the scientific integrity and appropriate use of the C2R data for research and publications. Operational responsibilities of the Steering Committee will include oversight of the CAS operator/facility credentialing process as well as developing and improving other key aspects of registry functions.

    The steering committee will also have primary responsibility for oversight of the C2R and for ensuring that the terms of the registry framework described in this document are correctly and consistently applied. The SC will also have the discretion to modify elements of this framework if such changes are determined to be necessary for the successful implementation of the CREST-2 trial and C2R.

    All committee members are required to submit relationship with industry information and other relevant conflicts of interest.

    A five-person Management Team will carry out day-to-day management and regulatory responsibilities, reporting to the Steering Committee. Membership will include at least one leader from the surgical, stenting, and neurological communities. The registry Principal Investigator (PI) will be Brajesh K. Lal, Co-Principal Investigator of CREST-2.

Open or close this module Conditions
Conditions: Severe Carotid Artery Disease
Open or close this module Study Design
Study Type: Observational [Patient Registry]
Observational Study Model: Cohort
Time Perspective: Prospective
Biospecimen Retention:
Biospecimen Description:
Enrollment: 4000 [Anticipated]
Number of Groups/Cohorts 1
Target Follow-Up Duration: 12 Months
Open or close this module Groups and Interventions
Groups/Cohorts Interventions
Severe Carotid Artery Disease
Device: Carotid Artery Stent
Open or close this module Outcome Measures
Primary Outcome Measures:
1. Any stroke or death within 30 days after the stenting procedure.
[ Time Frame: 30 days ]

Open or close this module Eligibility
Study Population: Patients aged 18 - 80 years old with symptomatic or asymptomatic carotid artery disease.
Sampling Method: Non-Probability Sample
Minimum Age: 18 Years
Maximum Age: 80 Years
Sex: All
Gender Based:
Accepts Healthy Volunteers: No

Eligibility Criteria for C2R

Asymptomatic patients

  • Patient age ≥ 18 and ≤ 80
  • ≥70% stenosis, standard surgical risk for CEA
  • ≥70% stenosis, high anatomic risk for CEA
  • ≥70% stenosis, high physiologic risk for CEA, excluding patients with < 5 years life expectancy and/or any of the following diagnoses:
  • NYHA Class IV CHF
  • COPD on chronic continuous oxygen therapy
  • Childs D liver failure
  • End-stage renal failure
  • Cancer with metastatic spread and/or undergoing active chemotherapeutic treatment
  • Any dementia considered greater than "mild"

Symptomatic patients

For the purpose of this framework, symptomatic patients are defined by the following characteristics: ipsilateral carotid Transient Ischemic Attack (TIA), with neurologic symptoms persisting less than 24 hours; ipsilateral non-disabling stroke (modified Rankin Scale ≤ 2); ipsilateral transient monocular blindness: amaurosis fugax.

  • Patient age ≥ 18 and ≤ 80
  • ≥70% stenosis, standard surgical risk for CEA
  • ≥50% to 69% stenosis, high anatomic risk for CEA
  • ≥70% stenosis, high anatomic and/or physiologic risk for CEA - currently covered by Medicare, but sites will be strongly encouraged to voluntarily include these patients in the registry
  • ≥70% stenosis, post-CEA and -CAS - currently covered by Medicare, but sites will be strongly encouraged to voluntarily include these patients in the registry
  • ≥70% stenosis, post-irradiation - currently covered by Medicare, but sites will be strongly encouraged to voluntarily include these patients in the registry
Open or close this module Contacts/Locations
Central Contact Person: Alexa N Richie, DrHSc
Telephone: 844-956-1826
Study Officials: Brajesh K Lal, MD
Principal Investigator
University of Maryland
Locations: United States, Florida
Thomas G. Brott
Jacksonville, Florida, United States, 32224
Contact:Contact: Alexa N Richie, DrHSc 844-956-1826
Open or close this module IPDSharing
Plan to Share IPD:
Open or close this module References
Citations: Rothwell PM, Mehta Z, Howard SC, Gutnikov SA, Warlow CP. Treating individuals 3: from subgroups to individuals: general principles and the example of carotid endarterectomy. Lancet. 2005 Jan 15-21;365(9455):256-65. doi: 10.1016/S0140-6736(05)17746-0. PubMed 15652609
Available IPD/Information:

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