Effectiveness of Bridging Anticoagulation for Surgery (The BRIDGE Study)

February 8, 2016 updated by: Duke University

Bridging Anticoagulation in Patients Who Require Temporary Interruption of Warfarin Therapy for an Elective Invasive Procedure or Surgery

Blood thinners, such as warfarin, prevent blood clots from forming, thereby reducing the risk of a stroke or heart attack. When people undergo surgery or certain procedures, they must stop using warfarin to prevent too much bleeding during and after the surgery or procedure. Some doctors prescribe a different blood thinner, one that works more quickly and wears off more quickly, to bridge the gap between starting and stopping warfarin. However, this short-term treatment is expensive, may increase the risk of bleeding, and has not been proven effective. This study will determine whether a bridging blood thinner called dalteparin is helpful or harmful for people with atrial fibrillation who stop taking warfarin in preparation for surgery or a procedure.

Study Overview

Detailed Description

Approximately 2 million people in North America take the anticoagulant warfarin to prevent stroke, heart attack, and other events related to blood clots. Warfarin needs to be stopped before a person undergoes surgery or certain procedures because it can cause dangerous amounts of bleeding during and after surgery. Some doctors give a low molecular weight heparin (LMWH) to patients during the 2-week period when participants are without the effects of warfarin. The LMWH has the same effect as warfarin, but it acts and then leaves the system more quickly than warfarin. However, the LMWH is expensive, may increase the risk of bleeding, and has not been proven effective. This study will determine the safety and efficacy of an LMWH in adults with atrial fibrillation who stop warfarin in preparation for surgery.

Participation in this study will last between 36 and 67 days. Participation will involve nine points of contact with researchers, at least two of which will be in-person visits at the research clinic. The others will be conducted by phone. All points of contact will include assessments on possible bleeding and any new symptoms. The first two of these points of contact, will take place at the signing of the informed consent, which will involve a screening of medical records and random assignment of participants to receive either the LMWH dalteparin or placebo. Participants will self-administer a subcutaneous injection of their assigned treatment twice a day for 3 days before the surgery or procedure and for 6 days after. During the course of the study, when participants visit their primary physicians for regularly scheduled appointments, it will be recommended that they undergo two international normalized ratio (INR) tests of blood clotting ability between day 2 and 10 after the surgery or procedure. The remaining seven points of contact will occur sometime between the day before surgery and 37 days after surgery. One of the in-person visits will occur within the first week after surgery and will include assessments on possible bleeding, any new symptoms, and INR results.

Study Type

Interventional

Enrollment (Actual)

1884

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 Locations

    • North Carolina
      • Durham, North Carolina, United States, 27715
        • Duke Clinical Research Institute

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

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Receiving warfarin therapy for at least 3 months, administered to achieve an international normalized ratio (INR) range of 2.0 to 3.0
  • Requiring temporary interruption of warfarin for pre-specified elective procedure or surgery
  • Presence of one of the following conditions:

    1. Chronic (permanent or paroxysmal) nonvalvular atrial fibrillation, confirmed by at least one prior electrocardiography recording or pacemaker or acid citrate dextrose (ACD) interrogation
    2. Chronic (permanent or paroxysmal) valvular atrial fibrillation with evidence of mitral valvular heart disease, confirmed by the same criteria as nonvalvular atrial fibrillation
  • Presence of at least one of the following major stroke risk factors:

    1. Older than 75 years of age
    2. Hypertension
    3. Diabetes mellitus
    4. Congestive heart failure or left ventricular dysfunction
    5. Previous ischemic stroke, systemic embolism, or transient ischemic attack (TIA)

Exclusion Criteria:

  • Any mechanical prosthetic heart valve
  • Stroke (ischemic or hemorrhagic), systemic embolism, or TIA within the past 12 weeks
  • Venous thromboembolism (deep vein thrombosis and/or pulmonary embolism) within past 12 weeks
  • Major bleeding within the past 6 weeks
  • Severe renal insufficiency, measured through a calculated creatinine clearance of less than 30 mL/min
  • Thrombocytopenia
  • Life expectancy less than 1 month
  • Condition that impairs compliance with trial protocol, such as cognitive impairment, an uncontrolled psychiatric condition, or geographic inaccessibility
  • Pregnancy
  • Allergy to heparin or history of heparin-induced thrombocytopenia
  • Having one of the following surgeries or procedures during warfarin interruption:

    1. Cardiac surgery, such as coronary artery bypass or heart valve replacement
    2. Neurosurgery that is intracranial or intraspinal, such as tumor resection or aneurysm repair
    3. High-risk non-surgical procedures, such as brain biopsy
  • Other surgical or non-surgical procedure that, at the discretion of the surgeon, precludes administration of therapeutic-dose low molecular weight heparin (LMWH) at any time in the post-procedure period
  • More than one surgery planned during the trial period
  • Prior participation in this 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: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Placebo
Normal saline solution, dosage determined by weight, self-administered by patient twice a day
Experimental: Dalteparin
Low molecular weight heparin (LMWH), dosage determined by weight, self-administered by patient twice a day
Other Names:
  • Fragmin

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of Arterial Thromboembolic Events
Time Frame: from subject signing of the consent until completed the study (Day -30 to Day +37)
The events are defined as arterial thromboembolism: stokes, transient ischemic attack and systemic embolism events were independently and blindly adjudicated
from subject signing of the consent until completed the study (Day -30 to Day +37)
Major Bleeding
Time Frame: from subject signing of the consent until completed the study (Day -30 to Day +37)
Major bleeding is defined as symptomatic bleeding associated with transfusion of more than two units of packed red blood cells or whole blood, or death
from subject signing of the consent until completed the study (Day -30 to Day +37)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of Subjects With Death, Acute Myocardial Infarction, Deep Vein Thrombosis, or Pulmonary Embolism
Time Frame: from subject signing of the consent until completed the study (Day -30 to Day +37)
from subject signing of the consent until completed the study (Day -30 to Day +37)
Number of Participants With Minor Bleeding
Time Frame: from subject signing of the consent until completed the study (Day -30 to Day +37)
Minor bleeding is defined as symptomatic or clinically-overt bleeding that does not satisfy the criteria for major bleeding
from subject signing of the consent until completed the study (Day -30 to Day +37)

Collaborators and Investigators

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

Sponsor

Investigators

  • Principal Investigator: Thomas L. Ortel, MD, Duke University
  • Principal Investigator: Victor Hasselblad, PhD, Duke Clinical 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.

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

July 1, 2009

Primary Completion (Actual)

February 1, 2015

Study Completion (Actual)

February 1, 2015

Study Registration Dates

First Submitted

November 5, 2008

First Submitted That Met QC Criteria

November 5, 2008

First Posted (Estimate)

November 6, 2008

Study Record Updates

Last Update Posted (Estimate)

March 7, 2016

Last Update Submitted That Met QC Criteria

February 8, 2016

Last Verified

January 1, 2016

More Information

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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