D-dimer to Establish Duration of Anticoagulation After Venous Thromboembolism
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The optimal duration of oral anticoagulant treatment in patients with idiopathic venous thromboembolism is still uncertain. The present study addresses the possible role of the D-dimer test in assessing the need for continuation of anticoagulation.The study aims at assessing whether D-dimer assay may have a role in guiding the duration of anticoagulation in these patients
Condition or disease
Deep Vein ThrombosisPulmonary Embolism
Drug: Vitamin K antagonist (Coumarin anticoagulants)
This is a multicenter prospective follow-up study in patients with a first episode of symptomatic idiopathic venous thromboembolism (proximal deep vein thrombosis and/or pulmonary embolism) who are treated with vitamin K antagonists (either warfarin or acenocoumarol) for a minimum of 3 months. Eligible patients who give informed consent are instructed to immediately stop oral anticoagulation and refrain from taking any other antithrombotic drugs until the next visit, scheduled after 30 days. At that visit, venous blood is sampled to perform D-dimer assay and thrombophilia tests. D-dimers are assessed using the Clearview Simplify D-dimer assay (Agen Biomedical Limited, Brisbane, Australia). Patients with normal D-dimer results do not continue anticoagulation, whereas those with elevated D-dimer results are randomized using a computer program to either stop or resume anticoagulation with vitamin K antagonists (INR 2.0-3.0). All patients are followed-up for 18 months. The study outcome are the composite of confirmed recurrent venous thromboembolism and major bleeding events. All suspected outcome events and all deaths are evaluated by a central adjudication committee whose members are unaware of the D-dimer and thrombophilia results and of the group assignments.
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Ages Eligible for Study:
18 Years and older (Adult, Senior)
Sexes Eligible for Study:
Accepts Healthy Volunteers:
Age > 18 years
After a first documented idiopathic proximal deep vein thrombosis and/or pulmonary embolism
After at least 3 months of oral anticoagulation
After written informed consent
If the Venous thromboembolism occurred:
during pregnancy or puerperium
after recent (i.e. within three months) fracture or plaster casting of a leg,
after immobilization with confinement to bed for three consecutive days
after surgery with general anesthesia lasting longer than 30 minutes
antiphospholipid antibody syndrome
serious liver disease or renal insufficiency (creatininemia > 2 mg/dL),
other indications for anticoagulation or contraindications for this treatment
limited life expectation
Patients who live too far from the clinical center
Fibrin fragment D
Fibrin Modulating Agents
Molecular Mechanisms of Pharmacological Action
Physiological Effects of Drugs