Clinical trial NCT02297373: Clinical Predictors for Venous Thromboembolism in Patients With a History of Thrombosis (PREDICTORS)
Official title: Clinical Predictors for Venous Thromboembolism in Patients With a History of Thrombosis
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Thromboembolic Disease Recurrent
Deep Vein Thrombosis
Pulmonary Embolism
Venous Thromboembolism
Recurrent Thromboembolic Disease
Lead sponsor: Ottawa Hospital Research Institute
Sponsor class: OTHER
First posted: 2014-11-21
Enrollment: 747
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Outpatients presenting with suspected acute recurrent VTE.

Brief summary: Patients with a history of blood clots are at risk of developing additional clots in the future. Doctors use a tool called a clinical decision rule to tell them how likely it is that a patient has a blood clot and if they should have further testing to look for the clot. This tool may cause doctors to over-diagnosis a recurrent clot because the symptoms may be left over from the previous clot. Correctly diagnosing a recurrent blood clot is very important since there are risks associated with both over-diagnosis and under-diagnosis. If a recurrent blood clot is missed (under-diagnosis) the patient is at risk of death from a clot in the lungs. If blood thinners are prescribed when they are not needed (over-diagnosis), the patient may have to take blood thinners for their lifetime and risk having serious bleeding.

Detailed description: Several tools have been developed to standardize the diagnostic management of a suspected first blood clot. One of these tools is the use of a clinical decision rule. Clinical decision rules have been designed to help clinicians make diagnostic and therapeutic decisions at the bedside. A score is computed on the presence of some criteria from the patient's medical history, clinical signs and symptoms. The score provides the probability of a blood clot. The rules can be used in combinations with a simple blood test - called D-dimer - to identify patients at low risk who don't require diagnostic imaging testing. Benefits include reduced costs, length in hospital and radiation exposure.

Patients with prior blood clots have been shown to be less likely to benefit from the non-invasive testing. Therefore, they often need to undergo imaging tests, which are frequently difficult to interpret in patients with prior blood clots since residual clots are often present and are difficult to distinguish from a recurrent clot.

The objective of this study is to try to prospectively assess the role of existing clinical decision rules in patients with prior blood clots, and to attempt to improve them in order to increase the yield of non-invasive testing and to reduce the risk of over-diagnosis with imaging tests.

With respect to this study, clots within the deep veins of the legs are called deep vein thrombosis (DVT), while clots in the lungs are called pulmonary embolism (PE).

Eligibility criteria: Inclusion Criteria:

* Outpatients with clinically suspected acute recurrent DVT or PE regardless of whether the previous event was a DVT or PE
* Age ≥18 years old
* Willing and able to give informed consent

Exclusion Criteria:

* Life expectancy less than 3 months
* Suspicion of upper extremity thrombosis or thrombosis at an unusual site (e.g. cerebral or abdominal venous thrombosis)
* Previous VTE was distal DVT or subsegmental PE
* Suspected recurrent VTE is asymptomatic
* Previously enrolled in this study

Primary outcomes:
measure: Validation of the Wells DVT clinical decision rule
timeFrame: 3 years
measure: Validation of the Wells PE clinical decision rule
timeFrame: 3 years
measure: Validation of the Geneva PE clinical decision rule
timeFrame: 3 years
Secondary outcomes:
measure: Clinical decision rule for suspected VTE in patients with a history of VTE
timeFrame: 3 years
measure: Accuracy of current D-dimer testing methods
timeFrame: 3 years
measure: Rate of confirmed events using current Wells DVT/Wells PE/Geneva PE in participants on anticoagulant therapy
timeFrame: 3 years
Other outcomes:
Locations:
city: Halifax
country: Canada
facility: Nova Scotia Health Authority
state: Nova Scotia
city: Hamilton
country: Canada
facility: Hamilton Health Sciences Centre
state: Ontario
city: London
country: Canada
facility: Lawson Health Research Institute
state: Ontario
city: Ottawa
country: Canada
facility: The Ottawa Hospital
state: Ontario
city: Ottawa
country: Canada
facility: Hopital Montfort
state: Ontario
city: Toronto
country: Canada
facility: Humber River Hospital
state: Ontario
city: Montreal
country: Canada
facility: Sir Mortimer B. Davis Jewish General Hospital
state: Quebec
city: Leiden
country: Netherlands
facility: Leiden University Medical Centre
city: Geneva
country: Switzerland
facility: Geneva University Hospital
Study officials:
affiliation: Ottawa Hospital
name: Gregoire Le Gal, MD
role: PRINCIPAL_INVESTIGATOR
References: