Uninterrupted Clopidogrel Therapy Before Elective Colonoscopy Will Increase the Risk of Post-polypectomy Bleeding

January 29, 2019 updated by: Francis KL Chan, Chinese University of Hong Kong
This double-blind, randomized trial aims to evaluate whether uninterrupted anti-platelet therapy (clopidogrel) will increase the risk of bleeding associated with removal of polyp during colonoscopy in patients with coronary artery disease.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

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

Clopidogrel is a potent anti-platelet agent that, when combines with aspirin, is essential in treating acute myocardial infarction and preventing coronary stent thrombosis. However, adding clopidogrel to aspirin has been shown to substantially increase the risk of gastrointestinal bleeding by 70%. This increased bleeding risk is a particular concern for patients requiring colonoscopy. The latter is a gold standard for screening colorectal cancer. This endoscopic procedure is increasingly performed for patients on anti-platelet drugs because coronary artery disease is associated with increased risk of colorectal neoplasia. We have shown that over 30% of patients with coronary artery disease have colorectal neoplasia.

Management of patients on clopidogrel who undergo colonoscopy is a clinical dilemma. Continuation of clopidogrel may increase the risk of bleeding associated with endoscopic resection of polyps (post-polypectomy bleeding). This is a potentially serious complication because post-polypectomy bleeding is often delayed, difficult to locate, and may provoke acute coronary syndrome. Conversely, prolonged discontinuation of clopidogrel increases the risk of recurrent myocardial infarction and coronary stent thrombosis.

There is a lack of prospective data on the risk of post-polypectomy bleeding attributable to clopidogrel. Current American Society of Gastrointestinal Endoscopy and British Society of Gastroenterology Guidelines recommend withholding clopidogrel for 7 to 10 days in planned high risk endoscopic procedures such as colonoscopic polypectomy. However, this guideline is largely based on retrospective data and expert opinion. In fact, the anti-platelet effect of clopidogrel lasts for about 5 days only. Coronary stent thrombosis has been reported as early as 7 days after stopping clopidogrel. There remains a large gap in our knowledge on the risk of bleeding in patients taking clopidogrel who undergo gastrointestinal endoscopic procedures.

No randomized trials have assessed whether clopidogrel should be discontinued before colonoscopy. This randomized trial aims to assess whether uninterrupted clopidogrel therapy during colonoscopy will increase the risk of post-polypectomy bleeding. Irrespective of the outcome, this trial will be the first to provide controlled data on the risk of post-polypectomy bleeding with uninterrupted clopidogrel during colonoscopy. Unfortunately, this important clinical question is not a priority of pharmaceutical companies because clopidogrel will be off patent soon. The outcome of this industry-independent clinical trial may encourage health authorities and international guideline committees to review their recommendations on the management of anti-platelet therapy for high-risk endoscopic procedures.

Hypothesis Uninterrupted clopidogrel therapy increases the risk of post-polypectomy bleeding in patients undergoing elective colonoscopy

Aim To investigate whether uninterrupted clopidogrel therapy before elective colonoscopy will increase the risk of post-polypectomy bleeding

Study Design This is a double-blind, randomized, controlled trial in which patients receiving clopidogrel for coronary stents who require elective colonoscopy will be randomized to either clopidogrel or its placebo for one week prior to the endoscopic procedure

Colonoscopic Procedures Experienced colonoscopists will perform colonoscopy under conscious sedation with midazolam and pethidine. Bowel preparation consists of polyethylene glycol taken orally the evening and the morning before procedure together with a minimum of 2 liters of clear fluids. The adequacy of bowel preparation will be documented (poor, fair, good, or excellent). Colonoscopists will be instructed to remove all polyps during the colonoscopic examination. The location and morphologic feature of each polyp will be recorded. The size is measured using an open biopsy forceps (6 mm apart). Each lesion will be fixed in formalin and sent to the pathologist for histologic evaluation. No prophylactic clips or detachable loops will be applied if immediate bleeding is not observed after polypectomy. Intervention for immediate post-polypectomy bleeding including injection therapy alone or in combination with endoclip application, if any, will be recorded.

Follow-up assessment All patients will resume their usual prescriptions of clopidogrel after colonoscopy when oral intake is allowed. They will be monitored hourly for hemodynamic instability and any delayed post-polypectomy bleeding for 24 hours. After discharge, a designated research nurse will contact the patients by telephone on Day 2 and Day 7 for symptoms of bleeding. On Day 30, they will return for a full blood count and symptoms of delayed post-polypectomy bleeding. Emergency visits and hospital discharge summaries will be scanned for up to 6 months after colonoscopy for recurrent cardiothrombotic events. A 24-hour hotline will be provided for patients to report any adverse or serious events.

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 (Actual)

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.
216

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.
  • Phase 4

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

  • China
    • Hong Kong
      • Hong Kong, Hong Kong, China
        • Prince of Wales Hospital

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

14 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. On regular treatment with clopidogrel alone or in combination with other anti-platelet drugs (e.g. aspirin)
  2. Elective colonoscopy for asymptomatic screening of bowel cancer or investigation of bowel symptoms (e.g. altered bowel habit, rectal bleeding, anemia, polyp follow-up)
  3. Age ≥ 18
  4. Written informed consent

Exclusion Criteria:

  1. Coronary stent of any type placed within 30 days
  2. Cardiac-vascular event within 3 months
  3. Drug-eluting coronary stent placed within 6 months
  4. Terminal illness
  5. Concomitant use of anticoagulants
  6. Congenital or acquired bleeding diathesis showing clinical bleeding tendency (e.g. hemophilia, decompensated cirrhosis)
  7. Pregnancy or women of child-bearing age without regular use of contraception

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: Quadruple

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.
Active Comparator: Clopidogrel
Continue clopidogrel for 7 days prior to the endoscopic procedure
Drug: clopidogrel
Clopidogrel 7 days prior to the endoscopic procedure (Colonoscopy)
Other Names:
  • Plavix
Placebo Comparator: Placebo
Placebo daily for 7 days prior to the endoscopic procedure
Other: Placebo
Placebo for 7 days prior to the endoscopic procedure (Colonoscopy)

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
Delayed post-polypectomy bleeding
Time Frame: 30 days post-colonoscopy
The primary endpoint is delayed post-polypectomy bleeding. The latter is defined as rectal bleeding, starting after the colonoscope has been retracted from the anus to 30 days after the procedure.
30 days post-colonoscopy

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
Immediate post-polypectomy bleeding
Time Frame: Within 5 minutes after polypectomy
bleeding at the time of polypectomy that persists despite continuous irrigation with diluted epinephrine solution for 5 minutes.
Within 5 minutes after polypectomy
Serious Cardiothrombotic events
Time Frame: 6 months after colonoscopy
defined according to the antithrombotic trialists' criteria
6 months after colonoscopy

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.
Chinese University of Hong Kong

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: Francis KL Chan, MD, CUHK

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.
February 1, 2012

Primary Completion (Actual)

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.
April 1, 2018

Study Completion (Actual)

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.
April 1, 2018

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).
March 4, 2013

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.
March 5, 2013

First Posted (Estimate)

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.
March 7, 2013

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.
January 31, 2019

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.
January 29, 2019

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.
January 1, 2019

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.
  • UCP

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.

Clinical Trials on Gastrointestinal Bleeding

Clinical Trials on clopidogrel

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

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