D-dimer Levels During and After Anticoagulation in Patients With a Previous Venous Thromboembolism: Effects on the Risk of Recurrence

Study Overview
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Brief Summary
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The results of the Prolong study, currently submitted for publication, show that patients with a first unprovoked venous thromboembolic event who have altered D-dimer levels, measured one month after anticoagulation with vitamin K antagonists is stopped, have a high rate of recurrences (about 14%) and a prolongation of anticoagulation is effective in reducing significantly this rate. Those patients with normal D-dimer (about 60% of all patients examined) have a low rate of recurrences (about 5%) and likely a prolongation of anticoagulation in all these patients cannot be recommended. In line with these results, the Prolong-Two study aims at assessing the predictive role for recurrence of D-dimer levels measured: a) during anticoagulation, b) one month after its withdrawal and c) periodically during follow up. Patients with a first unprovoked venous thromboembolism (including proximal deep vein thrombosis of a leg and/or pulmonary embolism) which are treated with vitamin K antagonists for not less than 6 months are considered for the study. D-dimer assay is performed during anticoagulation and patients with altered results continue the anticoagulation for 6 more months. Those with normal D-dimer stop the anticoagulant treatment and are again examined one month later. Anticoagulation is resumed for 6 more months in those patients with abnormal D-dimer results but is permanently stopped in those with a normal assay. The latter patients are examined and D-dimer assay performed again every two months to evaluate the natural history of the assay after anticoagulation is stopped and the possible predictive value for recurrence of a change of the assay during follow-up from normal to abnormal results.

Official Title
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A Multicentre, Prospective, Observational Study on the Predictive Role for Recurrence of D-dimer Levels Measured During and After Anticoagulation in Patients With a First Venous Thromboembolism Episode (the PROLONG-II Study)

Conditions
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Deep Vein Thrombosis, Pulmonary Embolism

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria Age > 18 years After a first documented idiopathic proximal deep vein thrombosis and/or pulmonary embolism After at least 6 months of oral anticoagulation After written informed consent Exclusion Criteria: Age > 82 y Recurrent venous thromboembolism 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 Patients with: active cancer antiphospholipid antibody syndrome antithrombin deficiency 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

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 82 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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D-dimer, Deep Vein Thrombosis, Pulmonary Embolism, Recurrence, Duration of Anticoagulation, Vitamin K Antagonists