Highest Efficacy of Dual Antiplatelet Therapy After Carotid Artery Stenting in High Bleeding Risk Patients

July 12, 2026 updated by: Woo-Keun Seo

Clinical Trial to Obtain the Highest Efficacy of Dual Antiplatelet Therapy After Carotid Artery Stenting in High Bleeding Risk Patients

The optimal duration of dual antiplatelet therapy (DAPT) after carotid artery stenting (CAS) in patients at high bleeding risk (HBR) has not been established in randomized controlled trials. Current practice largely extrapolates from percutaneous coronary intervention (PCI) trials, but anatomical and procedural differences between coronary and carotid arteries limit the validity of this approach.

The CHET trial is a multicenter, randomized, open-label, superiority trial designed to compare two DAPT durations after CAS in patients at HBR. After CAS, all eligible patients receive aspirin (100 mg daily) and clopidogrel (75 mg daily) for a 30-day enrichment period. Patients who remain free of net clinical events at day 30 are randomized 1:1 to either single antiplatelet therapy (SAPT; aspirin 100 mg or clopidogrel 75 mg daily, at the treating physician's discretion) for 11 months, or continued DAPT for 11 months.

The primary hypothesis is that abbreviated DAPT followed by SAPT is superior to prolonged DAPT in reducing clinically significant bleeding (Bleeding Academic Research Consortium [BARC] type 2, 3, or 5) from 30 days to 12 months after CAS, while maintaining noninferiority in net clinical outcomes (composite of nonfatal stroke, nonfatal myocardial infarction, cardiovascular death, and major bleeding [BARC type 3 or 5]).

A total of 1,556 participants (778 per group) will be enrolled across multiple comprehensive stroke centers in the Republic of Korea. Patients will be followed at 5 and 11 months after randomization, with subsequent annual follow-up (in-person or by telephone) until study completion to capture long-term clinical events.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
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

  1. Study Design CHET is a prospective, multicenter, randomized, open-label, superiority trial conducted at comprehensive stroke centers in the Republic of Korea. Endpoint adjudication is performed by an independent Clinical Event Assessment Committee (CEAC) blinded to treatment allocation, and safety is overseen by an independent Data Safety Monitoring Board (DSMB).
  2. Randomization Patients who complete the 30-day enrichment period without a net clinical event are randomized 1:1 via a centralized, secure web-based system using permuted blocks of variable size, stratified by participating center. The allocation sequence and block sizes are concealed from investigators to maintain allocation concealment.

  3. Treatment Arms (11 months following randomization) Experimental arm (SAPT): Single antiplatelet therapy with either aspirin 100 mg once daily or clopidogrel 75 mg once daily, at the treating physician's discretion, for 11 months.

    Active comparator arm (DAPT): Continued dual antiplatelet therapy with aspirin 100 mg once daily and clopidogrel 75 mg once daily for 11 months.

  4. Follow-up Scheduled outpatient visits are performed at 5 months and 11 months after randomization (corresponding to approximately 6 and 12 months after CAS). Following the 11-month visit, participants are followed annually through outpatient visits or telephone contact until study completion in December 2029 to capture long-term clinical events. Antiplatelet therapy after the randomized 11-month treatment period is at the discretion of the treating physician and is not mandated by the protocol.
  5. Endpoints 1) Primary safety endpoint: Clinically significant bleeding (BARC type 2, 3, or 5) occurring from 30 days to 12 months after CAS.

2) Key secondary efficacy endpoint: Net clinical outcome, defined as the composite of nonfatal stroke, nonfatal myocardial infarction, cardiovascular death, and major bleeding (BARC type 3 or 5), occurring from 30 days to 12 months after CAS, evaluated under a noninferiority hypothesis (margin 5%, one-sided alpha 2.5%).

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.
Interventional

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.
1556

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

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

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • South Korea
      • Seoul, South Korea, 06351
        • Recruiting
        • Samsung Medical Center
        • Contact:
          • Woo-Keun Seo, Ph.D

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Patients ≥19 years
  2. Symptomatic patients with carotid artery stenosis* greater than 50% and asymptomatic patients with carotid artery stenosis* greater than 70% who are scheduled to undergo or who have undergone carotid artery stenting

  3. High bleeding risk is defined as a Bleeding Academic Research Consortium type 3 or 5 bleeding risk of ≥4% at 1 year or a risk of an intracranial hemorrhage (ICH) of ≥1% at 1 year, Patients who meet at least one of the criteria for high bleeding risk** below

    • The degree of stenosis is determined using the method performed in the North American Symptomatic Carotid Endarterectomy Trial.

      • Criteria for high bleeding risk (≥ 1)

        • Incidence of non-access site bleeding within 12 months prior to stenting (gastrointestinal tract or hematuria)
        • Presence of BARC type 3 or 5 bleeding regardless of the onset time, but the cause has not been completely cured.
        • Adults aged ≥75 years
        • Thrombocytopenia < 100,000/mm3 (based on the screening test)
        • Blood clotting disorders that increase bleeding (Von Willebrand disease, factor VII, VIII, IX, and XI deficiency)
        • Patients with anemia defined as hemoglobin <12g/dL in men and <11g/dL in women or patients who donated blood within 4 weeks (based on the screening test)
        • Patients received steroids or NSAIDs for ≥4 weeks
        • Patients with active malignancy (except for nonmelanoma skin cancer)
        • Renal disease (dialysis, transplantation, Estimated Glomerular Filtration Rate < 60ml/min per 1.73m2)
        • Liver disease (cirrhosis with portal hypertension)
        • Cerebral microbleeds ≥ 5
        • Stroke or transient ischemic attacks within 6 months or Transient amaurosis fugax
        • Incidence of nontraumatic intracerebral hemorrhage regardless of duration or incidence of traumatic intracerebral hemorrhage within 12 months

Exclusion Criteria:

  1. Incidence of net clinical events, including cardiovascular and cerebrovascular accidents or major bleeding events, within 30 days following carotid artery stenting
  2. Discontinuation of dual antiplatelet therapy within 30 days after carotid stent implantation (However, use of a single antiplatelet therapy within 7 days due to acute infection and trauma is allowed, but dual antiplatelet therapy must be administered at 28 to 30 days after carotid stent implantation)
  3. Coronary artery stenting or other vascular stenting or vascular recanalization within 1 year (Revascularization surgery that requires CABG(Coronary Artery Bypass Graft) and other dual antiplatelet therapy)
  4. Aspirin or clopidogrel hypersensitivity
  5. Pregnant or breastfeeding women (Women of childbearing need to check for pregnancy using urine or blood tests before enrollment, and use appropriate contraception methods during the clinical trial period)
  6. Patients requiring anticoagulation for ≥12 months
  7. Patients requiring administration of other antiplatelet therapies
  8. Patients who are participating in another intervention clinical trial

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

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
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.
Experimental: Single antiplatelet therapy (SAPT) group with aspirin or clopidogrel
1 month of dual antiplatelet therapy(100mg aspirin q.d. and 75mg clopidogrel q.d.)→ Randomization → 11 months of single antiplatelet therapy (100mg aspirin q.d. or 75mg clopidogrel q.d.)
Drug: Intervention 1(DAPT): Drug: Aspirin 100mg + Clopidogrel 75mg. Intervention 2(SAPT): Drug: Asprin 100mg or Clopidogrel 75mg

  • Arm A : Single antiplatelet therapy (SAPT) with aspirin or clopidogrel

    - 1 month of dual antiplatelet therapy(100mg aspirin q.d. and 75mg clopidogrel q.d.)→ Randomization → 11 months of single antiplatelet therapy (100mg aspirin q.d. or 75mg clopidogrel q.d.)

  • Arm B : Dual antiplatelet therapy (DAPT) with aspirin and clopidogrel - 1 month of dual antiplatelet therapy(100mg aspirin q.d. and 75mg clopidogrel q.d.) → Randomization → 11 months of dual antiplatelet therapy (100mg aspirin q.d. and 75mg clopidogrel q.d.)
Other Names:
  • Aspirin and,or Clopidogrel
Active Comparator: Dual antiplatelet therapy (DAPT) with aspirin and clopidogrel
1 month of dual antiplatelet therapy(100mg aspirin q.d. and 75mg clopidogrel q.d.) → Randomization → 11 months of dual antiplatelet therapy (100mg aspirin q.d. and 75mg clopidogrel q.d.)
Drug: Intervention 1(DAPT): Drug: Aspirin 100mg + Clopidogrel 75mg. Intervention 2(SAPT): Drug: Asprin 100mg or Clopidogrel 75mg

  • Arm A : Single antiplatelet therapy (SAPT) with aspirin or clopidogrel

    - 1 month of dual antiplatelet therapy(100mg aspirin q.d. and 75mg clopidogrel q.d.)→ Randomization → 11 months of single antiplatelet therapy (100mg aspirin q.d. or 75mg clopidogrel q.d.)

  • Arm B : Dual antiplatelet therapy (DAPT) with aspirin and clopidogrel - 1 month of dual antiplatelet therapy(100mg aspirin q.d. and 75mg clopidogrel q.d.) → Randomization → 11 months of dual antiplatelet therapy (100mg aspirin q.d. and 75mg clopidogrel q.d.)
Other Names:
  • Aspirin and,or Clopidogrel

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
Clinically significant bleeding
Time Frame: From 30 days after carotid artery stenting until 12 months
Bleeding Academic Research Consortium type 2, 3, or 5
From 30 days after carotid artery stenting until 12 months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Combined cardiovascular and cerebrovascular accidents
Time Frame: From 30 days after carotid artery stenting until 12 months
Combined outcome of nonfatal stroke, nonfatal myocardial infarction, death due to cardio- and cerebrovascular diseases, and major bleeding events
From 30 days after carotid artery stenting until 12 months

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.
Woo-Keun Seo

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.
Dong-A ST Co., Ltd.

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.

General Publications

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 15, 2024

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.
November 30, 2029

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.
December 31, 2030

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).
February 13, 2024

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.
February 16, 2024

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.
February 26, 2024

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.
July 14, 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.
July 12, 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

Keywords

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.
  • SMC 2023-12-107

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.

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