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Deep Vein ThrombosisNCT00261014

Understanding Risk Factors Involved in Developing a Second Blood Clot.

An observational study of Deep Vein Thrombosis, run by Ottawa Hospital Research Institute at 7 sites in 2 countries.

Unknown status

Status not confirmed. The sponsor has not verified this record for over two years, so it may be out of date.

Official record
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Trial 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… Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Deep Vein Thrombosis
How many people
800 participants
Where
7 sitesin 2 countries
Study dates
Oct 2002to Mar 2016
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Study population: patients diagnosed with idiopathic blood clots

Who may be able to join

  • 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
  • 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.
  • Patients currently on oral anticoagulants

Who cannot join

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

Trial locations and contacts

7 sites in 2 countries.

7 sites in 2 countries

Canada6 sites

  • QE II Health Sciences Centre

    Halifax, Nova Scotia, B3H 2Y9

  • London Health Sciences Centre

    London, Ontario, N6A 4G5

  • Montreal General Hospital

    Montreal, Quebec, H3G 1A4

  • Montreal Jewish General Hospital

    Montreal, Quebec, H3T 1E2

  • Hopital du Sacre Coeur

    Montreal, Quebec, H4J 1C5

  • The Ottawa Hospital

    Ottawa, Ontario, K1H 8L6

Other trials in Canada

France1 site

  • CHU de le Cavale Blanche

    Brest

Other trials in France

About this study

Official title: 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.

Read the 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.

Keywords
Recurrent, Idiopathic, Deep Vein Thrombosis, Pulmonary Embolism, Clinical Prediction Rule, Venous Thromboembolism, Risk Factors
Medical subject headings
Venous Thrombosis, Recurrence, Pulmonary Embolism, Venous Thromboembolism

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Incidence of adjudicated recurrent VTE during study follow-up

    Measured: 8 years

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted2 Dec 2005 (estimated)
  2. Study startOct 2002
  3. Primary completionMar 2016 (estimated)
  4. Study completionMar 2016 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Time perspective
Prospective
Enrolment
800 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT00261014
Sponsor's protocol ID
2002452-01H
Status last verified
Nov 2015
First submitted
30 Nov 2005
Last updated
18 Nov 2015
Results posted
No
Data monitoring committee
No

Publications

  • 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.

    PubMed 29224973

  • 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.

    PubMed 27086275

  • 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.

    PubMed 23279046

  • 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.

    PubMed 22646832

  • 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.

    PubMed 20561184

  • 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.

    PubMed 19228281

  • 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.

    PubMed 18725614

Questions about this trial

What is this clinical trial studying?

An observational study of Deep Vein Thrombosis, run by Ottawa Hospital Research Institute at 7 sites in 2 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: status not confirmed, as of the sponsor's last update on 18 Nov 2015. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 7 sites in Canada, France. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Results are not available in the source record.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Incidence of adjudicated recurrent VTE during study follow-up (time frame: 8 years). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT00261014, which also lists 7 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Nov 2015; AzTrials last refreshed its copy on 26 Oct 2026.

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