ABRIDGE: Low Molecular Weight Heparin in Bridging Patients After Mechanical Valve Replacement

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00298285
Recruitment Status : Completed
First Posted : March 2, 2006
Last Update Posted : November 9, 2007
Information provided by:
The Cleveland Clinic

Brief Summary:
The primary aim is to determine the rate of major bleeding and blood clots when using enoxaparin as a bridge to oral blood thinning medication in patients who have undergone mechanical valve replacement.

Condition or disease Intervention/treatment Phase
Mechanical Valve Replacement Warfarin Therapy Drug: enoxaparin Phase 4

Detailed Description:

Patients who undergo mechanical heart valve replacement are usually placed on long-term oral anticoagulation (blood thinning) medication to prevent blood clots from forming on the mechanical valve. This is started in the hospital with intravenous unfractionated heparin; patients must remain in the hospital while on unfractionated heparin. At the same time, an oral blood thinner is started (warfarin). This process is commonly referred to as "bridging." Once the warfarin reaches the proper level, the intravenous heparin is stopped.

This is a single center, non-randomized pilot study using twice a day enoxaparin injections in place of unfractionated heparin as a bridge to warfarin therapy. A total of approximately 100 patients will be enrolled. Patients will be instructed how to give the enoxaparin injections at home. Blood will be drawn every 1-2 days to monitor warfarin levels. Once discharged, patients will continue to have their blood level checked until warfarin is at the correct level, at which point enoxaparin will be discontinued. All patients who develop signs or symptoms of a stroke or abnormal blood clotting will be asked to return for an echocardiogram. An echocardiogram and 12-lead ECG will be done at approximately 30 days after the start of the study.

Additionally the first 100 consecutive patients who fit the inclusion criteria but do not consent to the enoxaparin strategy will be asked to enter a registry that will monitor their hospital stay and information from their routine 30 day follow-up visit will be collected.

Study Type : Interventional  (Clinical Trial)
Enrollment : 100 participants
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: ABRIDGE: Low Molecular Weight Heparin in Bridging Patients After Mechanical Valve Replacement. A Pilot Study
Study Completion Date : October 2006

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Blood Thinners
Drug Information available for: Heparin
U.S. FDA Resources

Primary Outcome Measures :
  1. arterial thromboembolism
  2. major bleeding

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

Patients meeting all the following will be considered for enrollment.

  1. Male or non-pregnant female (negative pregnancy test is required for women of child bearing potential) ≥ 18 of age who are able to provide informed consent and able to self-administer enoxaparin.
  2. Body weight ≥ 45kg and ≤ 150kg.
  3. Patients who are post prosthetic mechanical valve surgery and will need oral anticoagulation after discharge from the hospital.

    • One who has undergone valve replacement with mechanical prosthesis in the mitral position.
    • One who has undergone valve replacement with mechanical prosthesis in the aortic position.
    • One who has undergone valve replacement with mechanical prosthesis in the tricuspid position.

Exclusion Criteria:

Patients with any of the following will not be eligible for enrollment in the study:

  1. Contraindication or sensitivity to unfractionated heparin/ low molecular weight heparin: history of heparin associated thrombocytopenia, heparin induced thrombocytopenia, or heparin induced thrombotic thrombocytopenia syndrome;
  2. History of, or current, cardiogenic shock;
  3. Active endocarditis (requiring > 4 weeks of antibiotics);
  4. Active bleeding or bleeding diathesis;
  5. History of gastrointestinal bleeding and /or endoscopically verified ulcer disease within the last three months;
  6. Known proliferative diabetic retinopathy or history of intraocular bleeding;
  7. Ischemic stroke in the previous three months or any hemorrhagic stroke, known brain tumor, intracranial aneurysm or intracranial AV malformation;
  8. Renal insufficiency (cr clearance < 30 cc/min), cr clearance calculation:

    Women = 0.85 x (140 - age) x body weight (kg) / 72 x serum creat (mg/dl), Men = (140 - age) x body weight (kg) / 72 x serum creat (mg/dl), or patient with a renal transplant;

  9. Anemia (Hgb < 8 gm/dl);
  10. Thrombocytopenia (platelet count < 100 x 109/L);
  11. Liver disease demonstrated by ALT > 144u/L
  12. Uncontrolled hypertension (systolic blood pressure >180mmHg or diastolic blood pressure >100mmHg);
  13. Life expectancy less than 6 months;
  14. Moderate pericardial effusion as diagnosed by echo;
  15. Concomitant use of clopidogrel, or cyclooxygenase 1 or 2 inhibitors or use within seven days;

Non- medical exclusion

  1. Patients unable or unwilling to provide consent.
  2. Patients unable or unwilling to have follow-up echocardiogram.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00298285

United States, Ohio
Cleveland Clinic
Cleveland, Ohio, United States, 44195
Sponsors and Collaborators
The Cleveland Clinic
Principal Investigator: Allan Klein, MD The Cleveland Clinic Identifier: NCT00298285     History of Changes
Other Study ID Numbers: ABRIDGE
First Posted: March 2, 2006    Key Record Dates
Last Update Posted: November 9, 2007
Last Verified: January 2006

Keywords provided by The Cleveland Clinic:
mechanical valve replacement

Additional relevant MeSH terms:
Heparin, Low-Molecular-Weight
Fibrinolytic Agents
Fibrin Modulating Agents
Molecular Mechanisms of Pharmacological Action