Stenoses, CarotidC2LOENCT05465122
CREST-2 Long-term Observational Extension Study
An observational study of Stenoses, Carotid, run by Mayo Clinic at 64 sites in 3 countries.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 35 years and older
- Conditions the study is for
- Stenoses, Carotid
- What is being tested?
- Carotid Endarterectomy, FDA-approved carotid stents and Intensive Medical Management
- Type of treatment
- Surgery or procedure
- How many people
- 2,480 participants
- Where
- 64 sitesin 3 countries
- Study dates
- 5 Jul 2022to 31 Aug 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 35 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Patients with asymptomatic carotid stenosis previously randomized in the CREST-2 trial.
Who may be able to join
- Currently active or graduated participants in the CREST-2 randomized trial
- Able to provide written informed consent by self
- Fluent in English or Spanish
Who cannot join
- Unable to provide written informed consent
- Inability to follow study procedures
Trial locations and contacts
64 sites in 3 countries.
64 sites in 3 countries
United States61 sites
VA Ann Arbor
Ann Arbor, Michigan, 48105
Seton Medical Center
Austin, Texas, 78705
VA Medical Center
Baltimore, Maryland, 21201
Johns Hopkins University
Baltimore, Maryland, 21224
University of Alabama at Birmingham
Birmingham, Alabama, 35233
Massachusetts General Hospital
Boston, Massachusetts, 02114
St. Elizabeth's Medical Center
Boston, Massachusetts, 02135
SUNY Buffalo
Buffalo, New York, 14203
University of Virginia
Charlottesville, Virginia, 22908
University of Chicago Medical Center
Chicago, Illinois, 60637
Morton Plant Mease Healthcare
Clearwater, Florida, 33756
Henry Ford Health System
Detroit, Michigan, 48202
Duke University Medical Center
Durham, North Carolina, 27710
Endeavor Health/NorthShore University
Evanston, Illinois, 60201
Inova Fairfax Hospital
Falls Church, Virginia, 22042
Michigan Vascular Center
Flint, Michigan, 48532
Mission Cardiovascular Research Institute
Fremont, California, 94538
University of Florida Health at Shands
Gainesville, Florida, 32610
North Memorial Medical Center
Golden Valley, Minnesota, 55422
Pinnacle Health
Harrisburg, Pennsylvania, 17043
Hartford Hospital
Hartford, Connecticut, 06102
University of Iowa Hospitals & Clinics
Iowa City, Iowa, 52242
Lyerly Neurosurgery/Baptist Health
Jacksonville, Florida, 32207
University of Florida Jacksonville
Jacksonville, Florida, 32209
Mayo Clinic Jacksonville
Jacksonville, Florida, 32224
Wellmont CVA Heart Institute
Kingsport, Tennessee, 37660
Tennova Healthcare
Knoxville, Tennessee, 37934
Gundersen Clinic, Ltd.
La Crosse, Wisconsin, 54601
Sparrow Clinical Research Institute
Lansing, Michigan, 48912
Baptist Health
Lexington, Kentucky, 40503
Central Arkansas VA
Little Rock, Arkansas, 72143
Kaiser Permanente Los Angeles
Los Angeles, California, 90027
USC/Keck Medical Center
Los Angeles, California, 90033
University of California Los Angeles
Los Angeles, California, 90095
Miami Cardiac and Vascular Institute
Miami, Florida, 33176
Yale New Haven Hospital
New Haven, Connecticut, 16520
Ochsner Health System
New Orleans, Louisiana, 70121
Weill Cornell Medical College
New York, New York, 10065
Deaconess Heart Group
Newburgh, Indiana, 47630
Cardiovascular Institute NW Florida
Panama City, Florida, 32405
Hospital of University of Pennsylvania
Philadelphia, Pennsylvania, 19104
Mayo Clinic Pheonix
Phoenix, Arizona, 85054
VA Pittsburgh
Pittsburgh, Pennsylvania, 15240
Maine Medical Center
Portland, Maine, 04102
Oregon Health & Science University
Portland, Oregon, 97239
The Miriam Hospital
Providence, Rhode Island, 02906
Mayo Clinic Rochester
Rochester, Minnesota, 55905
University of Utah Hospitals & Clinics
Salt Lake City, Utah, 84132
Kaiser Permanente Divsion of Research
San Francisco, California, 94115
Kaiser Permanente San Francisco
San Francisco, California, 94115
VA Puget Sound
Seattle, Washington, 98108
White Oak Medical Center
Silver Spring, Maryland, 20904
Prairie Heart/St. John's Hospital
Springfield, Illinois, 62701
Mercy Hospital
St Louis, Missouri, 63141
St. Joseph's Medical Center
Stockton, California, 95204
Crouse Hospital
Syracuse, New York, 13210
Mercy Health St. Vincent
Toledo, Ohio, 43608
Banner University Medical Center
Tucson, Arizona, 85724
Wake Forest Baptist Health
Winston-Salem, North Carolina, 27157
Berks Cardiologists
Wyomissing, Pennsylvania, 19610
Michigan Heart
Ypsilanti, Michigan, 48197
Canada2 sites
Nova Scotia Health Authority
Halifax, Nova Scotia, B3H 3A7
Vancouver General Hospital
Vancouver, British Columbia, V5Z 1M9
About this study
Official title: 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.
Read the 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.
- Conditions
- Stenoses, Carotid
- Being tested
- Carotid Endarterectomy, FDA-approved carotid stents, Intensive Medical Management
- Medical subject headings
- Carotid Stenosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Carotid EndarterectomyProcedure or surgery
This is the standard proven therapy for carotid stenosis that involves an arteriotomy followed by removal of plaque and reconstruction of the vessel.
FDA-approved carotid stentsProcedure or surgery
This is the standard proven therapy for carotid stenosis that involves an arteriotomy followed by removal of plaque and reconstruction of the vessel.
Intensive Medical ManagementOther
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.
| Study group | Role | What they receive |
|---|---|---|
| Carotid Stenting Group (CAS) | Subjects assigned to the intensive medical management with carotid stenting group in the CREST-2 study (NCT02089217) Receives: Procedure: FDA-approved carotid stents; Other: Intensive Medical Management | |
| Carotid Endarterectomy Group (CEA) | Subjects assigned to the intensive medical management with carotid endarterectomy group in the CREST-2 study (NCT02089217) Receives: Procedure: Carotid Endarterectomy; Other: Intensive Medical Management | |
| 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) Receives: Other: Intensive Medical Management | |
| 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) Receives: Other: Intensive Medical Management |
What is being measured
The primary outcome is the main question the study is designed to answer.
Stroke
Number of participants to experience a stroke
Measured: 5 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Jul 2022
- Study start5 Jul 2022
- Primary completion31 Aug 2027 (estimated)
- Study completion31 Aug 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Stenoses, CarotidStudies of the same condition, open and under way.
- More trials run by Mayo ClinicThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 2,480 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Mayo Clinic
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute of Neurological Disorders and Stroke (NINDS), University of Alabama at Birmingham, University of Maryland, Medical University of South Carolina
- Responsible party
- Principal investigator, James F. Meschia, Mayo Clinic
- Investigators
- James Meschia, MD, Principal investigator, Mayo Clinic
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05465122
- Sponsor's protocol ID
- 21-007363
- Other IDs
- 1U01NS119169-01A1
- Acronym
- C2LOE
- Status last verified
- May 2026
- First submitted
- 30 Jun 2022
- Last updated
- 28 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 28 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Long-Term Observational Extension of Participants in the CREST-2 Randomized Clinical Trial
- ClinicalTrials.gov ID
- NCT05465122
- Acronym / sponsor ID
- C2LOE / 21-007363
- Conditions
- Stenoses, Carotid
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 2,480 participants (estimated)
- Lead sponsor
- Mayo ClinicUniversity, hospital or other
- Collaborators
- National Institute of Neurological Disorders and Stroke (NINDS), University of Alabama at Birmingham, University of Maryland, Medical University of South Carolina
- Study start
- 5 Jul 2022 (actual)
- Primary completion
- 31 Aug 2027 (estimated)
- Study completion
- 31 Aug 2027 (estimated)
- First posted
- 19 Jul 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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 design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Carotid Stenting Group (CAS) | – | Procedure: FDA-approved carotid stents, Other: Intensive Medical ManagementSubjects assigned to the intensive medical management with carotid stenting group in the CREST-2 study (NCT02089217) |
| Carotid Endarterectomy Group (CEA) | – | Procedure: Carotid Endarterectomy, Other: Intensive Medical ManagementSubjects assigned to the intensive medical management with carotid endarterectomy group in the CREST-2 study (NCT02089217) |
| Intensive Medical Management Group - no CAS | – | Other: Intensive Medical ManagementSubjects assigned to the intensive medical management alone with no carotid stenting (CAS) group in the CREST-2 study (NCT02089217) |
| Intensive Medical Management Group - no CEA | – | Other: Intensive Medical ManagementSubjects assigned to the intensive medical management alone with no carotid endarterectomy (CEA) group in the CREST-2 study (NCT02089217) |
Who may qualify
- Ages
- 35 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients with asymptomatic carotid stenosis previously randomized in the CREST-2 trial.
Key inclusion criteria (3 listed)
- Currently active or graduated participants in the CREST-2 randomized trial
- Able to provide written informed consent by self
- Fluent in English or Spanish
Key exclusion criteria (2 listed)
- Unable to provide written informed consent
- Inability to follow study procedures
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Carotid EndarterectomyThis is the standard proven therapy for carotid stenosis that involves an arteriotomy followed by removal of plaque and reconstruction of the vessel. | Procedure or surgery | Carotid Endarterectomy Group (CEA) |
| FDA-approved carotid stentsThis is the standard proven therapy for carotid stenosis that involves an arteriotomy followed by removal of plaque and reconstruction of the vessel. | Procedure or surgery | Carotid Stenting Group (CAS) |
| Intensive Medical ManagementINTERVENT 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. | Other | Carotid Endarterectomy Group (CEA), Carotid Stenting Group (CAS), Intensive Medical Management Group - no CAS, Intensive Medical Management Group - no CEA |
Primary outcome
Stroke
Time frame: 5 years
Number of participants to experience a stroke
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 May 2026.
- Mayo Clinic Clinical TrialsLink provided by the sponsor.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
James Meschia, MD principal investigator
Mayo Clinic
64 sites in 3 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Stenoses, Carotid, run by Mayo Clinic at 64 sites in 3 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 28 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 64 sites in United States, Canada, Spain. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Stroke (time frame: 5 years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 May 2026.