Understanding Risk Factors Involved in Developing a Second Blood Clot.

November 17, 2015 updated by: Ottawa Hospital Research Institute

REcurrent VEnous Thromboembolism Risk Stratification Evaluation A Study to Develop a Clinical Prediction Rule to Predict Low Recurrence Risk in Patients With Idiopathic Venous Thromboembolism.

The purpose of this study is to develop a way to predict which patients diagnosed with idiopathic blood clots can safely stop warfarin therapy after six months. We will use patient characteristics, blood test results and imaging test results to identify those patients who have the lowest risk of developing a new blood clot after warfarin is stopped.

Study Overview

Status

Unknown

Conditions

Detailed Description

The risk of recurrent VTE in patients with idiopathic VTE subsequent to three to six months of oral anticoagulant therapy remains high (5-27% per year). The risk of recurrent VTE, however, is not likely high enough to justify indefinite anticoagulation in all patients with a first idiopathic VTE due to the rate of major bleeding with oral anticoagulants (2-6% per year), the inconvenience and cost of oral anticoagulant therapy, monitoring of oral anticoagulant therapy (e.g. prescription costs, time off work to go for lab tests, parking etc) and the lifestyle limitations of oral anticoagulant therapy (avoidance of certain physical activities, dietary restrictions, avoidance of pregnancy). Further, as some have argued, perhaps all that anticoagulant therapy achieves is to delay recurrent VTE and, as a recent editorial suggested, a tailored approached is required to determine sub-groups who require lifelong anticoagulation. A means to stratify patients with idiopathic VTE to identify a group at low risk of recurrent VTE who could safely discontinue oral anticoagulants subsequent to six months of therapy would be a significant advance in the care of these patients.

Study Type

Observational

Enrollment (Anticipated)

800

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

  • Canada
    • Nova Scotia
      • Halifax, Nova Scotia, Canada, B3H 2Y9
        • QE II Health Sciences Centre
    • Ontario
      • London, Ontario, Canada, N6A 4G5
        • London Health Sciences Centre
      • Ottawa, Ontario, Canada, K1H 8L6
        • The Ottawa Hospital
    • Quebec
      • Montreal, Quebec, Canada, H3G 1A4
        • Montreal General Hospital
      • Montreal, Quebec, Canada, H3T 1E2
        • Montreal Jewish General Hospital
      • Montreal, Quebec, Canada, H4J 1C5
        • Hopital du Sacré Cœur
  • France
      • Brest, France
        • CHU de le Cavale Blanche

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

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

patients diagnosed with idiopathic blood clots

Description

Inclusion Criteria:

  1. Objectively proven (as previously described (8)) proximal idiopathic deep vein thrombosis or pulmonary embolism. Idiopathic will be defined as VTE occurring in the absence of fracture, plaster cast, immobilization greater than 3 days or a general anesthetic in the last three months prior to VTE diagnosis; a known deficiency of antithrombin, protein C or protein S; and malignancy in the last five years
  2. Patients treated initially with a minimum of five days of heparin or low molecular weight heparin and oral anticoagulants with a target intensity of 2.0 - 3.0 with no recurrence in the subsequent six months.
  3. Patients currently on oral anticoagulants

Exclusion Criteria:

  1. Recurrent idiopathic VTE (i.e. ≥ 2 previous idiopathic VTE). Previous secondary VTE is not an exclusion criterion;
  2. Age <18;
  3. Known deficiency of proteins S, protein C or antithrombin;
  4. Known, persistently positive anticardiolipin antibodies (titers > 30U/ml);
  5. Known, persistently positive lupus anticoagulant;
  6. Combined thrombophilic defects (e.g. homozygous for FVL or PGM, or compound heterozygous for FVL and PGM);
  7. Refusal of informed consent.

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

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Incidence of adjudicated recurrent VTE during study follow-up
Time Frame: 8 years
8 years

Collaborators and Investigators

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

Sponsor

Ottawa Hospital Research Institute

Collaborators

Canadian Institutes of Health Research (CIHR)
Heart and Stroke Foundation of Ontario
Biomerieux inc

Investigators

  • Principal Investigator: Marc Rodger, MD MSc, OHRI

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

October 1, 2002

Primary Completion (Anticipated)

March 1, 2016

Study Completion (Anticipated)

March 1, 2016

Study Registration Dates

First Submitted

November 30, 2005

First Submitted That Met QC Criteria

November 30, 2005

First Posted (Estimate)

December 2, 2005

Study Record Updates

Last Update Posted (Estimate)

November 18, 2015

Last Update Submitted That Met QC Criteria

November 17, 2015

Last Verified

November 1, 2015

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2002452-01H

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 Deep Vein Thrombosis

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Sri Lanka

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

3
Subscribe