Risk of Recurrent Venous Thrombosis: A Validation Study of the Vienna Prediction Model

Because of a high recurrence risk after unprovoked venous thromboembolism (VTE) indefinite anticoagulation is recommended, but confers a considerable bleeding risk. It is important to identify patients, in whom the recurrence risk is lower than the expected bleeding risk, and who will not benefit from long term anticoagulation. By use of a scoring model (Vienna Prediction Model), patients can be stratified according to their recurrence risk based on their sex, location of VTE and D-Dimer. Before implementation in routine care, an independent validation is required. Patients with unprovoked VTE will stop anticoagulation after 3-7 months and the recurrence risk will be estimated by use of the Vienna Prediction Model. Low risk patients with a score of <180 will be included and will be left untreated. Patients with a high score will not be included and their management will follow current guidelines. Follow-up will be two years and the endpoint will be recurrent symptomatic VTE.