CREST-2 Long-term Observational Extension Study (C2LOE)

May 26, 2026 updated by: James F. Meschia, Mayo Clinic

Long-Term Observational Extension of Participants in the CREST-2 Randomized Clinical Trial

The purpose of this Long-Term Observational Extension of Participants in the CREST-2 Randomized Clinical Trial (C2LOE - ClinicalTrials.gov Identifier: NCT02089217) study is to study is to assess post-procedural efficacy of carotid endarterectomy and carotid stenting.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Atherosclerotic plaque in the carotid arteries is responsible for 10 to 15% of all ischemic strokes. The ongoing NINDS-funded CREST-2 multicenter randomized clinical trial is testing whether in the short term (up to 4 years after study entry) procedural revascularization improves stroke prevention above and beyond what can be achieved with intensive medical management of vascular risk factors, especially hypertension and hyperlipidemia. Our proposal is for an observational extension of the CREST-2 clinical trial to test whether revascularization improves stroke prevention in the clinically relevant long term (up to 8 to 10 years). The current application proposes to use a site-less, centralized telephone approach to extend the follow-up of CREST-2 trial participants for assessing the primary study outcome (stroke) for up to 10 years. The average follow-up will increase from between 2-3 years (clinic-based randomized trial) to 7-8 years (observational extension). Each patient will be contacted by telephone at 6-month intervals, and queried regarding all hospitalizations since the last contact. Suspected stroke events will be adjudicated by an expert clinical events committee based on medical record review.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
2480

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • British Columbia
      • Vancouver, British Columbia, Canada, V5Z 1M9
        • Vancouver General Hospital
    • Nova Scotia
      • Halifax, Nova Scotia, Canada, B3H 3A7
        • Nova Scotia Health Authority
  • Spain
      • Barcelona, Spain, 08036
        • Hospital Clinic of Barcelona
  • United States
    • Alabama
      • Birmingham, Alabama, United States, 35233
        • University of Alabama at Birmingham
    • Arizona
      • Phoenix, Arizona, United States, 85054
        • Mayo Clinic Pheonix
      • Tucson, Arizona, United States, 85724
        • Banner University Medical Center
    • Arkansas
      • Little Rock, Arkansas, United States, 72143
        • Central Arkansas VA
    • California
      • Fremont, California, United States, 94538
        • Mission Cardiovascular Research Institute
      • Los Angeles, California, United States, 90095
        • University of California Los Angeles
      • Los Angeles, California, United States, 90027
        • Kaiser Permanente Los Angeles
      • Los Angeles, California, United States, 90033
        • USC/Keck Medical Center
      • San Francisco, California, United States, 94115
        • Kaiser Permanente San Francisco
      • San Francisco, California, United States, 94115
        • Kaiser Permanente Divsion of Research
      • Stockton, California, United States, 95204
        • St. Joseph's Medical Center
    • Connecticut
      • Hartford, Connecticut, United States, 06102
        • Hartford Hospital
      • New Haven, Connecticut, United States, 16520
        • Yale New Haven Hospital
    • Florida
      • Clearwater, Florida, United States, 33756
        • Morton Plant Mease Healthcare
      • Gainesville, Florida, United States, 32610
        • University of Florida Health at Shands
      • Jacksonville, Florida, United States, 32224
        • Mayo Clinic Jacksonville
      • Jacksonville, Florida, United States, 32209
        • University of Florida Jacksonville
      • Jacksonville, Florida, United States, 32207
        • Lyerly Neurosurgery/Baptist Health
      • Miami, Florida, United States, 33176
        • Miami Cardiac and Vascular Institute
      • Panama City, Florida, United States, 32405
        • Cardiovascular Institute NW Florida
    • Illinois
      • Chicago, Illinois, United States, 60637
        • University Of Chicago Medical Center
      • Evanston, Illinois, United States, 60201
        • Endeavor Health/NorthShore University
      • Springfield, Illinois, United States, 62701
        • Prairie Heart/St. John's Hospital
    • Indiana
      • Newburgh, Indiana, United States, 47630
        • Deaconess Heart Group
    • Iowa
      • Iowa City, Iowa, United States, 52242
        • University of Iowa Hospitals & Clinics
    • Kentucky
      • Lexington, Kentucky, United States, 40503
        • Baptist Health
    • Louisiana
      • New Orleans, Louisiana, United States, 70121
        • Ochsner Health System
    • Maine
      • Portland, Maine, United States, 04102
        • Maine Medical Center
    • Maryland
      • Baltimore, Maryland, United States, 21224
        • Johns Hopkins University
      • Baltimore, Maryland, United States, 21201
        • VA Medical Center
      • Silver Spring, Maryland, United States, 20904
        • White Oak Medical Center
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Massachusetts General Hospital
      • Boston, Massachusetts, United States, 02135
        • St. Elizabeth's Medical Center
    • Michigan
      • Ann Arbor, Michigan, United States, 48105
        • VA Ann Arbor
      • Detroit, Michigan, United States, 48202
        • Henry Ford Health System
      • Flint, Michigan, United States, 48532
        • Michigan Vascular Center
      • Lansing, Michigan, United States, 48912
        • Sparrow Clinical Research Institute
      • Ypsilanti, Michigan, United States, 48197
        • Michigan Heart
    • Minnesota
      • Golden Valley, Minnesota, United States, 55422
        • North Memorial Medical Center
      • Rochester, Minnesota, United States, 55905
        • Mayo Clinic Rochester
    • Missouri
      • St Louis, Missouri, United States, 63141
        • Mercy Hospital
    • New York
      • Buffalo, New York, United States, 14203
        • SUNY Buffalo
      • New York, New York, United States, 10065
        • Weill Cornell Medical College
      • Syracuse, New York, United States, 13210
        • Crouse Hospital
    • North Carolina
      • Durham, North Carolina, United States, 27710
        • Duke University Medical Center
      • Winston-Salem, North Carolina, United States, 27157
        • Wake Forest Baptist Health
    • Ohio
      • Toledo, Ohio, United States, 43608
        • Mercy Health St. Vincent
    • Oregon
      • Portland, Oregon, United States, 97239
        • Oregon Health & Science University
    • Pennsylvania
      • Harrisburg, Pennsylvania, United States, 17043
        • Pinnacle Health
      • Philadelphia, Pennsylvania, United States, 19104
        • Hospital of University of Pennsylvania
      • Pittsburgh, Pennsylvania, United States, 15240
        • VA Pittsburgh
      • Wyomissing, Pennsylvania, United States, 19610
        • Berks Cardiologists
    • Rhode Island
      • Providence, Rhode Island, United States, 02906
        • The Miriam Hospital
    • Tennessee
      • Kingsport, Tennessee, United States, 37660
        • Wellmont CVA Heart Institute
      • Knoxville, Tennessee, United States, 37934
        • Tennova Healthcare
    • Texas
      • Austin, Texas, United States, 78705
        • Seton Medical Center
    • Utah
      • Salt Lake City, Utah, United States, 84132
        • University of Utah Hospitals & Clinics
    • Virginia
      • Charlottesville, Virginia, United States, 22908
        • University of Virginia
      • Falls Church, Virginia, United States, 22042
        • INOVA Fairfax Hospital
    • Washington
      • Seattle, Washington, United States, 98108
        • VA Puget Sound
    • Wisconsin
      • La Crosse, Wisconsin, United States, 54601
        • Gundersen Clinic, Ltd.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Patients with asymptomatic carotid stenosis previously randomized in the CREST-2 trial.

Description

Inclusion Criteria:

  • Currently active or graduated participants in the CREST-2 randomized trial
  • Able to provide written informed consent by self
  • Fluent in English or Spanish

Exclusion Criteria:

  • Unable to provide written informed consent
  • Inability to follow study procedures

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Intensive Medical Management Group - no CAS
Subjects assigned to the intensive medical management alone with no carotid stenting (CAS) group in the CREST-2 study (NCT02089217)
Other: Intensive Medical Management
INTERVENT risk factor management program to help manage patient's risk factors. The INTERVENT program will provide individualized risk factor counseling sessions (via telephone or internet) at regular interval by healthcare workers who are specially trained to help patients follow the medical management plan.
Intensive Medical Management Group - no CEA
Subjects assigned to the intensive medical management alone with no carotid endarterectomy (CEA) group in the CREST-2 study (NCT02089217)
Other: Intensive Medical Management
INTERVENT risk factor management program to help manage patient's risk factors. The INTERVENT program will provide individualized risk factor counseling sessions (via telephone or internet) at regular interval by healthcare workers who are specially trained to help patients follow the medical management plan.
Carotid Stenting Group (CAS)
Subjects assigned to the intensive medical management with carotid stenting group in the CREST-2 study (NCT02089217)
Other: Intensive Medical Management
INTERVENT risk factor management program to help manage patient's risk factors. The INTERVENT program will provide individualized risk factor counseling sessions (via telephone or internet) at regular interval by healthcare workers who are specially trained to help patients follow the medical management plan.
Procedure: FDA-approved carotid stents
This is the standard proven therapy for carotid stenosis that involves an arteriotomy followed by removal of plaque and reconstruction of the vessel.
Carotid Endarterectomy Group (CEA)
Subjects assigned to the intensive medical management with carotid endarterectomy group in the CREST-2 study (NCT02089217)
Other: Intensive Medical Management
INTERVENT risk factor management program to help manage patient's risk factors. The INTERVENT program will provide individualized risk factor counseling sessions (via telephone or internet) at regular interval by healthcare workers who are specially trained to help patients follow the medical management plan.
Procedure: Carotid Endarterectomy
This is the standard proven therapy for carotid stenosis that involves an arteriotomy followed by removal of plaque and reconstruction of the vessel.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Stroke
Time Frame: 5 years
Number of participants to experience a stroke
5 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Mayo Clinic

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Medical University of South Carolina
University of Maryland
University of Alabama at Birmingham
National Institute of Neurological Disorders and Stroke (NINDS)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: James Meschia, MD, Mayo Clinic

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 5, 2022

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 31, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 31, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 30, 2022

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 15, 2022

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 19, 2022

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 28, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 26, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 21-007363
  • 1U01NS119169-01A1 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings