Hypercoagulability: too many tests, too much conflicting data.

It is now possible to identify hereditary and acquired risk factors in a substantial percentage of patients presenting with a venous thrombotic event. The clinician is faced with an ever-growing number of laboratory tests that can be ordered in such patients, and there is considerable uncertainty as to how this information should be utilized in patient management. Some have argued that widespread testing of thrombosis patients for prothrombotic abnormalities such as the factor V Leiden and prothrombin G20210A mutations has been prematurely adopted into clinical practice as there are few data that their identification leads to improved clinical outcomes. Dr. Rosendaal provides an overview of the epidemiology of venous thrombosis with an emphasis on hereditary and acquired risk factors. The presentation will include information obtained from properly designed case-control studies as well as family studies. While some have suggested treatment strategies for managing patients with hereditary thrombophilia with prior thrombotic events or for managing patients undergoing procedures associated with increased thrombotic risk, clinical decision making is complicated by the need to assess the risk of recurrence and the likely benefit of prolonged anticoagulation versus the associated bleeding risk. Drs. Bauer, Heit, and Rosendaal discuss their approaches to patient management. Case presentations are used to illustrate the impact of laboratory test results on decisions.