Clinical trial NCT00895505: D-Dimer Guided Oral Anticoagulant Treatment (OAT)
Official title: Safety and Efficacy of a D-Dimer-Guided Strategy for Extension of Secondary Prophylaxis of Venous Thromboembolism - a Prospective and Randomized Management Trial
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: PHASE3
Conditions: Deep Venous Thrombosis
Keywords: DVT
Venous thromboembolism
D-Dimer
thrombophilia
secondary prophylaxis
secondary prophylaxis using oral anticoagulant treatment (OAT)
higher risk of recurrence in patients showing increased levels
of D-Dimer after withdrawal of OAT
D-Dimer-based treatment
Lead sponsor: University Hospital, Bonn
Sponsor class: OTHER
Collaborators: name: German Research Foundation
name: German Federal Ministry of Education and Research
First posted: 2009-05-08
Enrollment: 300
Sex: ALL
Minimum age (years): 18
Maximum age (years): 85
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL

Brief summary: This clinical trial will investigate the hypothesis that D-Dimer testing can be successfully used to tailor the duration of OAT in patients after an unprovoked episode of deep venous thrombosis (DVT) using a prospective, randomized, and controlled design.

Detailed description: After a first episode of acute deep venous thrombosis (DVT) the risk of recurrence is relatively high and clinical consequences are important. Therefore, secondary prophylaxis using oral anticoagulant treatment (OAT) is usually established in these patients. This treatment very effectively reduces the risk of recurrences but induces an increased risk of bleeding. Major bleeding complications can be expected in \~2% patient-years. Therefore, current recommendations limit OAT to a period of 3 to 12 months. After stopping of OAT, however, \~10 % of patients with an initial episode of unprovoked DVT will develop a recurrent event within 1 year. This group of patients may benefit from prolonged OAT. The results of 2 independent observational studies showed a significantly higher risk of recurrence in patients showing increased levels of D-Dimer after withdrawal of OAT. D-Dimer is a biomarker that indicates fibrin formation followed by fibrinolysis. Based on these data we hypothesize that D-Dimer testing can be successfully used to tailor the duration of OAT in patients after an unprovoked episode of DVT. This clinical trial will investigate this hypothesis using a prospective, randomized, and controlled design.

Eligibility criteria: Inclusion Criteria:

To be enrolled in this study, patients must:

* have an objectively confirmed first episode of unprovoked VTE or of VTE during a minor transient risk factor. Minor transient risk factors include 6 weeks of estrogen therapy, prolonged air travel (i.e., \> 6 hours), pregnancy, less marked leg injuries or immobilization without injury or surgical intervention
* be scheduled to receive oral anticoagulant treatment for at least 3 months
* be willing to be randomized
* be willing to participate for the full duration of the study

Exclusion Criteria:

* pregnancy or breast feeding
* contraindications against OAT (i.e., intracranial hemorrhage, subarachnoid hemorrhage, hemorrhagic stroke)
* age \< 18 years
* presence of antiphospholipid antibodies or any other thrombophilic risk factor requiring long-term OAT (i.e., antithrombin deficiency, hereditary PC deficiency)
* poor patient compliance

Primary outcomes:
measure: Incidence and severity of objectively documented deep vein thrombosis (DVT) and/or pulmonary embolism (PE)
timeFrame: Duration of intervention per patient (24 months)
Secondary outcomes:
measure: Incidence and severity of signs and symptoms associated with OAT-induced bleeding measured using the World Health Organization (WHO) bleeding scale.
timeFrame: Duration of intervention per patient (24 months)
Other outcomes:
Locations:
city: Bonn
country: Germany
facility: Institut für Experimentelle Hämatologie und Transfusionsmedizin, Universitätsklinikum Bonn
state: Nordrhein-Westfalen
Study officials:
affiliation: Institut für Experimentelle Hämatologie und Transfusionsmedizin, Universitätsklinikum Bonn
name: Bernd Poetzsch, Professor
role: PRINCIPAL_INVESTIGATOR
References: