Non-vitamin K antagonist oral anticoagulants for the prevention of recurrent venous thromboembolism

Venous thromboembolism (VTE) is associated with a risk of recurrence that depends on factors specific to index event and patient. A first unprovoked VTE increases the risk of a recurrent event, particularly during the first year after anticoagulation cessation. Determining a strategy for the long-term prevention of recurrent VTE poses challenges that stem from a lack of agreement on recommended therapy duration and varying treatment burden for the patient. Oral anticoagulants, including vitamin K antagonists and non-vitamin K antagonist oral anticoagulants (NOACs), are the main treatment options for the long-term prevention of recurrent VTE. However, the risk of VTE recurrence must be balanced against the risk of bleeding in each patient. Phase III clinical trials have evaluated rivaroxaban, apixaban and dabigatran for extended treatment and prevention of VTE versus placebo, and versus warfarin in the case of dabigatran. Compared with placebo treatment, each NOAC showed superior efficacy together with an acceptable safety profile during extended treatment periods of 6-18months. Patients receiving long-term NOAC therapy will still require regular risk factor assessment, but these agents may permit longer treatment duration with an improved benefit-risk profile.