Understanding Risk Factors Involved in Developing a Second Blood Clot.

NCT ID: NCT00261014

Last Updated: 2015-11-18

Basic Information

• Recruitment Status: UNKNOWN
• Total Enrollment: 800 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2002-10-31
• Study Completion Date: 2016-03-31

Brief Summary

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.

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.

Conditions

Deep Vein Thrombosis

Study Design

• Study Time Perspective: PROSPECTIVE

Eligibility Criteria

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.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Canadian Institutes of Health Research (CIHR)

OTHER_GOV

Sponsor Role: collaborator

Biomerieux inc

INDUSTRY

Sponsor Role: collaborator

Heart and Stroke Foundation of Ontario

OTHER

Sponsor Role: collaborator

Ottawa Hospital Research Institute

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Marc Rodger, MD MSc

Role: PRINCIPAL_INVESTIGATOR

OHRI

Locations

QE II Health Sciences Centre

Halifax, Nova Scotia, Canada

London Health Sciences Centre

London, Ontario, Canada

The Ottawa Hospital

Ottawa, Ontario, Canada

Montreal General Hospital

Montreal, Quebec, Canada

Montreal Jewish General Hospital

Montreal, Quebec, Canada

Hopital du Sacre Coeur

Montreal, Quebec, Canada

CHU de le Cavale Blanche

Brest, , France

Countries

Canada; France

References

Wan T, Rodger M, Zeng W, Robin P, Righini M, Kovacs MJ, Tan M, Carrier M, Kahn SR, Wells PS, Anderson DR, Chagnon I, Solymoss S, Crowther M, White RH, Vickars L, Bazarjani S, Le Gal G. Residual pulmonary embolism as a predictor for recurrence after a first unprovoked episode: Results from the REVERSE cohort study. Thromb Res. 2018 Feb;162:104-109. doi: 10.1016/j.thromres.2017.11.020. Epub 2017 Dec 8.

Reference Type: DERIVED

PMID: 29224973 (View on PubMed)

Rodger MA, Scarvelis D, Kahn SR, Wells PS, Anderson DA, Chagnon I, Le Gal G, Gandara E, Solymoss S, Sabri E, Kovacs J, Kovacs MJ. Long-term risk of venous thrombosis after stopping anticoagulants for a first unprovoked event: A multi-national cohort. Thromb Res. 2016 Jul;143:152-8. doi: 10.1016/j.thromres.2016.03.028. Epub 2016 Mar 29.

Reference Type: DERIVED

PMID: 27086275 (View on PubMed)

Galanaud JP, Holcroft CA, Rodger MA, Kovacs MJ, Betancourt MT, Wells PS, Anderson DR, Chagnon I, Le Gal G, Solymoss S, Crowther MA, Perrier A, White RH, Vickars LM, Ramsay T, Kahn SR. Predictors of post-thrombotic syndrome in a population with a first deep vein thrombosis and no primary venous insufficiency. J Thromb Haemost. 2013 Mar;11(3):474-80. doi: 10.1111/jth.12106.

Reference Type: DERIVED

PMID: 23279046 (View on PubMed)

Galanaud JP, Holcroft CA, Rodger MA, Kovacs MJ, Betancourt MT, Wells PS, Anderson DR, Chagnon I, Le Gal G, Solymoss S, Crowther MA, Perrier A, White RH, Vickars LM, Ramsay T, Kahn SR. Comparison of the Villalta post-thrombotic syndrome score in the ipsilateral vs. contralateral leg after a first unprovoked deep vein thrombosis. J Thromb Haemost. 2012 Jun;10(6):1036-42. doi: 10.1111/j.1538-7836.2012.04713.x.

Reference Type: DERIVED

PMID: 22646832 (View on PubMed)

Kovacs MJ, Kahn SR, Wells PS, Anderson DA, Chagnon I, LE Gal G, Solymoss S, Crowther M, Perrier A, Ramsay T, Betancourt MT, White RH, Vickars L, Rodger MA. Patients with a first symptomatic unprovoked deep vein thrombosis are at higher risk of recurrent venous thromboembolism than patients with a first unprovoked pulmonary embolism. J Thromb Haemost. 2010 Sep;8(9):1926-32. doi: 10.1111/j.1538-7836.2010.03958.x.

Reference Type: DERIVED

PMID: 20561184 (View on PubMed)

Le Gal G, Kovacs MJ, Carrier M, Do K, Kahn SR, Wells PS, Anderson DA, Chagnon I, Solymoss S, Crowther M, Righini M, Perrier A, White RH, Vickars L, Rodger M. Validation of a diagnostic approach to exclude recurrent venous thromboembolism. J Thromb Haemost. 2009 May;7(5):752-9. doi: 10.1111/j.1538-7836.2009.03324.x. Epub 2009 Feb 18.

Reference Type: DERIVED

PMID: 19228281 (View on PubMed)

Rodger MA, Kahn SR, Wells PS, Anderson DA, Chagnon I, Le Gal G, Solymoss S, Crowther M, Perrier A, White R, Vickars L, Ramsay T, Betancourt MT, Kovacs MJ. Identifying unprovoked thromboembolism patients at low risk for recurrence who can discontinue anticoagulant therapy. CMAJ. 2008 Aug 26;179(5):417-26. doi: 10.1503/cmaj.080493.

Reference Type: DERIVED

PMID: 18725614 (View on PubMed)

Other Identifiers

2002452-01H

Identifier Type: -

Identifier Source: org_study_id