Reducing Gastrointestinal Bleeding With Proton Pump Inhibitor Therapy in Acute Venous Thromboembolism

January 20, 2026 updated by: Ottawa Hospital Research Institute

Reducing Gastrointestinal Bleeding With Proton Pump Inhibitor Therapy in Acute Venous Thromboembolism: Pilot Randomized Study (RADIANT Study)

The investigators are studying whether treatment with a proton pump inhibitor called omeprazole reduces gastrointestinal bleeding in older adults taking blood thinners for a blood clot (venous thromboembolism). The purpose of this study, a pilot study or a feasibility study, is to test the study plan and determine whether enough participants will join a larger study and accept the study procedures.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Venous thromboembolism (VTE) refers to blood clots that form in the veins of the body, including the arms or legs (deep vein thrombosis [DVT]), abdomen (portal vein thrombosis), or lungs (pulmonary embolism [PE]). These blood clots are treated with medication to reduce blood clotting called anticoagulants. The main complication of anticoagulants is bleeding, the majority of which comes from the stomach or intestines (gastrointestinal tract). Anticoagulants do not cause bleeding, but they may make bleeding worse. Uncommonly, serious gastrointestinal (GI) bleeding can happen leading to hospitalization and even death. The chance of bleeding is highest in the first few months after starting anticoagulants.

Proton pump inhibitors (PPIs) are medications that lower the acid content of the stomach. The medication in this study, a type of proton pump inhibitor called omeprazole, is approved in Canada for treating stomach ulcers, heartburn, and a stomach infection called Helicobacter pylori. The use of omeprazole in this study is considered investigational. This means that Health Canada has not approved the use of omeprazole as a treatment for preventing gastrointestinal bleeding in patients taking anticoagulants. Some studies suggest that they may reduce gastrointestinal bleeding for people taking anticoagulants.

The investigators are studying whether treatment with a proton pump inhibitor called omeprazole reduces gastrointestinal bleeding in older adults taking anticoagulants for venous thromboembolism.

The investigators plan to do a large, randomized trial which is the best way to test the effect of a treatment. To do this, some of the participants in this study will get omeprazole and others will get a placebo (a substance that looks like the study omeprazole but does not have any active or medicinal ingredients). The placebo in this study is not intended to have any effect on bleeding. A placebo is used to make the results of the study more reliable.

Primary Objective To assess the feasibility of a full-scale double-blind placebo-controlled randomized trial to determine whether omeprazole reduces the risk of upper GI bleeding in older adults receiving anticoagulation for acute VTE compared to placebo.

Secondary Objectives:

  1. To measure additional feasibility outcomes
  2. To measure informative outcomes
  3. To measure key clinical outcomes

Study Type

Interventional

Enrollment (Estimated)

360

Phase

  • Phase 3

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

  • Name: Deborah Siegal, MD
  • Phone Number: 78804 (613) 737-8899
  • Email: dsiegal@toh.ca

Study Locations

  • Canada
    • Ontario
      • Ottawa, Ontario, Canada, K1H 8L6
        • Recruiting
        • The Ottawa Hospital
        • Principal Investigator:
          • Deborah Siegal, MD
        • Contact:
        • Contact:
      • St. Catharines, Ontario, Canada, L2S 0A9
        • Not yet recruiting
        • Niagara Health System - St. Catharines Site
        • Principal Investigator:
          • Blair Leonard, MD
        • Contact:
      • Toronto, Ontario, Canada, M5G 2c4
        • Recruiting
        • University Health Network - Toronto General
        • Principal Investigator:
          • Peter Gross, MD
        • Contact:
    • Quebec

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

Ages Eligible for Study

  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Male or female 65 years or older at the time of enrolment. Enrolment is limited to older adults as age is an important non-modifiable risk factor for bleeding. This will ensure the study population includes participants who may be more likely to benefit from omeprazole (compared to those with no risk factors) because all participants will have at least 1 risk factor for bleeding.
  2. Newly diagnosed VTE which includes VTE at any site such as (but not limited to) DVT of upper or lower limbs, PE, cerebral vein thrombosis, portal vein thrombosis, other splanchnic vein thrombosis.
  3. Planned for 3 months (90 days) or more of therapeutic anticoagulation with any anticoagulant.
  4. Patient or delegate is able and willing to comply with follow-up examinations contained within the consent form.

Exclusion Criteria:

  1. Therapeutic anticoagulation therapy for more than 7 days
  2. Currently prescribed PPI for regular daily use (patients receiving H2 receptor antagonists will not be excluded),
  3. Previous upper GI bleeding,
  4. Need for dual antiplatelet therapy,
  5. Contraindications to omeprazole (hypersensitivity to omeprazole, or other substituted benzimidazole PPIs, concomitant use with products that contain rilpivirine, significant drug interactions, up to the discretion of the site investigator),
  6. Life expectancy is less than 3 months.

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
Intervention / Treatment
Experimental: Daily dose of omeprazole 20 mg
Participants randomized to the experimental arm will take one omeprazole 20 mg tablet by mouth every day for the duration of their participation in the study.
Drug: Omeprazole 20 mg Oral Tablet
Omeprazole once daily for 90 days
Other Names:
  • Omeprazole
Placebo Comparator: Daily dose of placebo
Participants randomized to the control arm will take one placebo tablet by mouth every day for the duration of their participation in the study.
Other: Placebo
Placebo once daily for 90 days

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Study feasibility at participating centres
Time Frame: 24 months
The mean number of participants recruited per site per month
24 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Eligibility Rate
Time Frame: 24 months
Proportion of screened patients who are eligible
24 months
Consent Rate
Time Frame: 24 months
Proportion of eligible patients who provide consent
24 months
Retention Rate
Time Frame: 27 months
Proportion of participants who completed all study procedures
27 months
Adherence Rate
Time Frame: 27 months
adherence to study drug measured by pill count or assessing the patient diary at the end of follow-up
27 months

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Risk Factors
Time Frame: 24 months
The proportion of participants with the following risk factors for bleeding at baseline: decreased kidney function (defined as estimated glomerular filtration rate [eGFR] <60 mL/min/1.73 m2), active cancer, concurrent antiplatelet and/or NSAID therapy, chronic liver disease, chronic anemia.
24 months
Patients already prescribed proton pump inhibitor
Time Frame: 24 months
The proportion of screened patients already receiving prescribed proton pump inhibitor therapy
24 months
Reasons for Declining Participation
Time Frame: 24 months
Patients are not required to provide a reason for declining to participate. However, for those patients who are willing to share, reasons for declining participation will be reviewed
24 months
New PPI prescription
Time Frame: 27 months
The proportion of participants with new prescription for proton pump inhibitor during the study
27 months
Recurrent VTE
Time Frame: 27 months
The proportion of patients that have a recurrent venous thromboembolism during the study
27 months
Mortality
Time Frame: 27 months
The proportion of patients who die from gastrointestinal bleeding, and all-cause mortality during the study
27 months
Serious Adverse Events
Time Frame: 27 months
The proportion of patients who have a serious adverse event during the study
27 months
Change in health-related quality of life
Time Frame: 27 months
Change in health-related quality of life as measured by the EuroQol EQ-5D-5L Quality of Life questionnaire at 90 days compared to baseline. This questionnaire includes the patient's thoughts about their health, including mobility, self-care, usual activities, pain or discomfort, and anxiety or depression. The lowest possible score is 5 and the highest is 25. A lower score represents a worse quality of life. The questionnaire also includes a Visible Analog Scale where patients are asked to picture a vertical line that is numbered from 0 to 100. 100 at the top of the line means the best health the patient can imagine and 0 at the bottom of the line means the worst health the patient can imagine. Patients are asked to provide a number that best represents their health at the time of completing the questionnaire.
27 months
Change in functional status
Time Frame: 27 months
Change in functional status as measured by the Standard Assessment of Global Activities in the Elderly (SAGE) scale at 90 days compared to baseline. The SAGE questionnaire measures what patients are doing in their community and their homes. Patients are asked to indicate the level of difficulty they have with each of the questions in the past month with a response of no difficulty, mild, moderate, or severe difficulty. Mild = minimal/occasional difficulty that does not affect the ability to perform the activity or task; Moderate = some/regular difficulty that does affect the ability to perform the task, although they may still be able to perform the task; Severe = extreme/constant difficulty performing the task or the task is not completed and/or is completed by someone else because of its difficulty.
27 months
Clinically Relevant Upper Gastrointestinal Bleeding Events
Time Frame: 27 months
Adjudicated clinically relevant upper gastrointestinal bleeding (major upper gastrointestinal bleeding plus clinically relevant non-major [CRNM] upper GI bleeding, adapted from International Society on Thrombosis and Haemostasis (ISTH) criteria for major bleeding and CRNM bleeding).
27 months
Rate of endoscopically confirmed upper gastrointestinal bleeding
Time Frame: 27 months
Proportion of patients who have upper gastrointestinal bleeding as confirmed by endoscope at 30, 60, and 90 days post randomization
27 months
Rate of lower gastrointestinal bleeding
Time Frame: 27 months
Proportion of patients who have lower gastrointestinal bleeding at 30, 60, and 90 days post randomization
27 months
All major gastrointestinal bleeding
Time Frame: 27 months
Proportion of patients who have confirmed major gastrointestinal bleeding by adjudication at 30, 60, and 90 days post randomization
27 months
All clinically relevant non-major gastrointestinal bleeding
Time Frame: 27 months
Proportion of patients who have confirmed clinically relevant non-major gastrointestinal bleeding by adjudication at 30, 60. 90 days
27 months
All major bleeding
Time Frame: 27 months
Proportion of patients who have confirmed major bleeding by adjudication, including major GI bleeding) at 30, 60, 90 days post randomization
27 months
All clinically relevant non-major bleeding
Time Frame: 27 months
Proportion of patients who have confirmed clinically relevant non-major bleeding (including CRNM GI bleeding) at 30, 60, and 90 days post randomization
27 months
Hospitalization for gastrointestinal bleeding
Time Frame: 27 months
Proportion of patients hospitalized for gastrointestinal bleeding at 30, 60. and 90 days post randomization
27 months

Collaborators and Investigators

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

Sponsor

Ottawa Hospital Research Institute

Investigators

  • Principal Investigator: Deborah Siegal, MD, Ottawa Hospital Research Institute

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)

November 6, 2024

Primary Completion (Estimated)

December 1, 2027

Study Completion (Estimated)

March 1, 2028

Study Registration Dates

First Submitted

March 19, 2024

First Submitted That Met QC Criteria

April 26, 2024

First Posted (Actual)

May 1, 2024

Study Record Updates

Last Update Posted (Actual)

January 22, 2026

Last Update Submitted That Met QC Criteria

January 20, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • RADIANT-001

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

CONVERGE trials will be conducted within specific research domains under a core protocol outlining shared elements, including broad inclusion criteria, a minimum set of core outcomes, event adjudication, and data sharing to the CONVERGE shared data repository. Patients meeting domain-specific inclusion criteria can be enrolled in individual trials based on pre-defined additional characteristics. RADIANT will be the first trial conducted within the Acute VTE Treatment Domain.

IPD Sharing Time Frame

Starting after study completion

IPD Sharing Access Criteria

Select members of the International Network of VENous Thromboembolism Clinical Research Networks (INVENT) participating in CONVERGE trials will enter into an agreement to enhance data-sharing and meta-analysis across trials. Access will be restricted by strict authentication processes and data will be maintained on secure servers.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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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