Management of thrombophilia.

It is now possible to identify acquired and hereditary risk factors in a substantial percentage of patients presenting with a venous thrombotic event. Discovery of the factor V Leiden and prothrombin G20210A mutations has greatly increased the percentage of patients in whom venous thrombosis can be attributed to hereditary thrombophilia. There is, however, considerable uncertainty as to how this information should be used in patient management. Although prolonged anticoagulation at an international normalized ratio of 2-3 is highly effective in preventing thrombotic recurrences, this benefit is partially offset by major bleeding which occurs at an average rate of 2%-3% per year. A decision as to the overall benefit of extended anticoagulation in the individual patient requires assessment of the risk of recurrence in the absence of treatment vs. the bleeding risk associated with prolonged anticoagulation. Low-intensity warfarin therapy or novel anticoagulants such as oral direct thrombin inhibitors may prove effective strategies for preventing recurrent venous thromboembolism in patients with thrombophilia.