Risk of recurrence and optimal duration of anticoagulation

Abstract

Venous thromboembolism (VTE) requires anticoagulant therapy to prevent recurrent VTE. Recurrent VTE may cause acute morbidity, be life-threatening, be fatal, and/or disabling. After completing initial short-term anticoagulant therapy, clinicians and patients must weigh and balance the risk/consequences of recurrent VTE and the benefits of continuing anticoagulants against the major bleeding risks of extended anticoagulant therapy in addition to the costs and burdens of extended anticoagulant therapy. The risk of recurrent VTE after completing anticoagulant therapy is highly dependent on the presence of a provoking factor associated with the index VTE and the strength of this provoking factor. Patients with VTE provoked by a major transient risk factor have a low risk of recurrent VTE and can discontinue anticoagulants after short-term therapy. Patients with VTE provoked by an ongoing major risk factor, patients with recurrent VTE, and patients with potent thrombophilia require extended anticoagulant therapy. There is considerable uncertainty in patients with unprovoked VTE and patients with VTE associated with minor transient risk factors. This chapter discusses clinical decision rules and other approaches to assist clinicians and patients in making this important lifelong decision.