Risk assessment for recurrence and optimal agents for extended treatment of venous thromboembolism.

Venous thromboembolism (VTE) has a variable recurrence rate after the discontinuation of anticoagulant treatment. Therefore, the duration of anticoagulation therapy after a first VTE should be tailored to the estimated risk for recurrence. Anticoagulant therapy should be discontinued after the initial 3 to 6 months in those patients who had the first episode in association with temporary risk factors. The duration of anticoagulant therapy in patients who had a first episode of cancer-associated VTE should be reassessed over time based on the persistence of cancer and anticancer therapy. After 3 to 6 months of anticoagulant treatment for VTE, patients with a first unprovoked event and an estimated low risk for bleeding complications should be evaluated for indefinite treatment on an individualized basis. New oral anticoagulants have been evaluated for the extended treatment of VTE. Large phase 3 studies have shown that dabigatran, rivaroxaban, and apixaban are effective and safe in this indication. These agents do not require monitoring for dose adjustment and could make extended treatment more feasible and acceptable to patients.