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Clinical Decision Rule Validation Study to Predict Low Recurrent Risk in Patients With Unprovoked Venous Thromboembolism

Phase 4
Completed
Conditions
Idiopathic Venous Thromboembolism
Interventions
Other: Application of the"Men continue and HER DOO2" rule
Registration Number
NCT00967304
Lead Sponsor
Ottawa Hospital Research Institute
Brief Summary

The main objective of this study is to verify whether a new clinical decision rule identifying patients diagnosed with unprovoked blood clots who have a low risk of recurrence can safely stop oral anticoagulant therapy after 5-7 months of treatment.

Detailed Description

Up to 50% of patients with a first episode of venous thromboembolism (VTE) have no identifiable cause (i.e. are unprovoked VTEs). The risk of recurrent VTE in this large group of patients with unprovoked VTE after 3-6 months of anticoagulant therapy is 5-10.8% in the year following discontinuation of oral anticoagulant therapy. One in six to one in twenty recurrences of a new VTE are fatal. Given the intermediate risks of recurrence in unselected unprovoked VTE patients, clinicians do not have clear guidance on whether to continue or discontinue anticoagulants in patients with unprovoked VTE. Recently attention has turned to the concept of risk stratification to identify subgroups of patients with unprovoked VTE who could safely discontinue oral anticoagulation therapy (OAT).

In the REVERSE I study, a clinical decision rule derivation study conducted from 2001 to 2006, we developed and internally validated the clinical decision rule "Men continue and HER DOO2" that identifies patients with a first unprovoked VTE who likely have a low risk of recurrent VTE and could safely discontinue OAT subsequent to 5-7 months of OAT. The present study will evaluate if the "Men continue and HER DOO2" rule (comprised of gender, elevated D-dimer levels, post-thrombotic signs, obesity, and older age) is safe, clinically useful, and reproducible when prospectively implemented in multiple centers and a variety of settings. If this clinical decision rule is validated, it will provide physicians with important information to allow them to more confidently identify unprovoked VTE patients at low risk of VTE recurrence who may not need to continue OAT.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
2779
Inclusion Criteria
  • First episode of major unprovoked VTE
  • VTE objectively proven
  • VTE treated for 5-12 months with anticoagulant therapy authorized for the REVERSE II study (initial or ongoing therapy)
  • Absence of recurrent VTE during the treatment period
Exclusion Criteria
  • Less than 18 years of age
  • Patients who have already discontinued anticoagulant therapy
  • Patients requiring ongoing anticoagulation for reasons other than VTE
  • Being treated for a recurrent unprovoked VTE
  • Patients with high risk thrombophilia
  • patients who plan on using exogenous estrogen(OCP,HRT)if anticoagulant therapy is discontinued
  • Patients with pregnancy associated VTE
  • Geographically inaccessible for follow-up
  • Patients unable or unwilling to provide informed consent

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
1 Discontinue OAT or AAAApplication of the"Men continue and HER DOO2" rulePatients classified as being at low risk of recurrent VTE by the "HER DOO2"rule. If the clinical decision rule indicates that a patient is at low recurrence risk (\<3% per year); anticoagulant therapy will be withdrawn and the participant will then be followed for 1 year for any VTE recurrence and/or bleeding.
Primary Outcome Measures
NameTimeMethod
The primary study outcome is the incidence of adjudicated recurrent major VTE at 1 year in patients deemed by the "Men and HER DOO2" CDR to be at low risk of recurrent VTE.One year
Secondary Outcome Measures
NameTimeMethod
Any VTE 1 year event rate in low risk patientsOne year
Clinical utility of the ruleOne year
Major bleeding 1 year event rate in un-anticoagulated low risk patientsOne year
Major VTE 1 year event rate in high risk patients who continue anticoagulant therapyOne year
Major VTE 1 year event rate in high risk patients who discontinue anticoagulant therapyOne year
Major Bleeding 1 year event rate in high risk patientsOne year
Inter-observer reliability of the clinical decision ruleOne year

Trial Locations

Locations (23)

Penobscot Bay Medical Center

🇺🇸

Rockport, Maine, United States

UC Davis

🇺🇸

Santa Monica, California, United States

Prince of Wales Hospital

🇦🇺

Sydney, New South Wales, Australia

Ottawa Health Research Institute

🇨🇦

Ottawa, Ontario, Canada

Hamilton Health Sciences Corporation

🇨🇦

Hamilton, Ontario, Canada

SMBD Jewish General Hospital

🇨🇦

Montreal, Quebec, Canada

St. Mary's Hospital - CHUM

🇨🇦

Montreal, Quebec, Canada

Hopital Enfant Jesus

🇨🇦

Quebec, Canada

Centre Hospitalier Regional Universitaire de Brest

🇫🇷

Brest, France

Sahyadri Speciality Hospital

🇮🇳

Pune, India

Orange Lifesciences

🇮🇳

Nirmaya, India

Jashvant Patel Clinic

🇮🇳

Surat, India

Hopitaux Universitaires de Geneve

🇨🇭

Geneva, Switzerland

University Health Network

🇨🇦

Toronto, Ontario, Canada

Victoria Hospital

🇨🇦

London, Ontario, Canada

CDHA-Queen Elizabeth II Health Science Centre

🇨🇦

Halifax, Nova Scotia, Canada

Hamilton Health Sciences Center

🇨🇦

Hamilton, Ontario, Canada

Hopital Sacre Coeur

🇨🇦

Montreal, Quebec, Canada

McGill University Health Centre

🇨🇦

Montreal, Quebec, Canada

Saskatchewan Drug Research Institute

🇨🇦

Saskatoon, Saskatchewan, Canada

CUB Hopital Erasme

🇧🇪

Brussels, Belgium

Shefali Centre

🇮🇳

Shefali, India

Duke University

🇺🇸

Durham, North Carolina, United States

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