Thrombophilia testing has limited usefulness in clinical decision-making and should be used selectively

Management of venous thromboembolism (VTE) includes evaluation for hypercoagulable state, especially if the VTE occurs in young patients, is recurrent, or is associated with a positive family history. These laboratory tests are costly, and surprisingly, there is little evidence showing that testing leads to improved clinical outcomes. Evidence based on observational prospective studies suggests that optimal duration of anticoagulation should be based on clinical risks resulting in VTE, such as transient, permanent, and idiopathic or unprovoked risks, and less on abnormal thrombophilia values. Thrombophilia screening is important in a subgroup of clinical scenarios, such as when there is clinical suspicion of antiphospholipid antibody syndrome, heparin resistance, or warfarin necrosis; with thrombosis occurring in unusual sites (such as mesenteric or cerebral deep venous thrombosis); and for pregnant women or those seeking pregnancy or considering estrogen-based agents. Thrombophilia screening is not likely to be helpful in most cases of first-time unprovoked VTE in the setting of transient risks, active malignant disease, deep venous thrombosis of upper extremity veins or from central lines, two or more VTEs, or arterial thrombosis with pre-existing atherosclerotic risk factors. The desire by both patient and physician for a scientific explanation of the clotting event may alone lead to testing, and if so, it should be with the understanding that an abnormal test result will likely not change management, and normal results do not accurately exclude a thrombophilic defect because there are likely factors yet to be discovered. Such false assumptions may lead to shorter durations of treatment than are optimal.