No thrombophilia testing is indicated in this patient. No evidence indicates that identification of a thrombophilia in this patient would influence the duration or intensity of anticoagulant therapy. Consequently, the American Society of Hematology recommends against thrombophilia testing in patients who develop a venous thromboembolism (VTE) in the setting of a major transient risk factor (surgery, trauma, or prolonged immobility). The appropriate duration of anticoagulation for this patient with VTE due to recent trauma and major surgery is 3 months, regardless of identification of a thrombophilia. It is unclear which patients benefit from thrombophilia testing. It may be appropriate to consider evaluation for a strong thrombophilia in a patient with VTE who is at intermediate risk for recurrent VTE by traditional recurrence risk factors. These are patients with a thromboembolism associated with minor VTE risk factors, such as women with hormone- or pregnancy-associated VTE or men or women with VTE associated with minor immobility or minor surgery. Finding a strong thrombophilia in these patients may be one of the indications for long-term anticoagulation.
Antiphospholipid antibodies (APLAs) impart a greater risk of arterial and venous thromboembolism. Although the prothrombin time (PT) and activated partial thromboplastin time (aPTT) may be elevated in patients with APLAs, they are not adequately sensitive or specific to indicate the presence or absence of this cause of thrombophilia. If antiphospholipid syndrome is suspected, APLA tests (lupus anticoagulant, anticardiolipin antibodies, and anti-β2-glycoprotein I antibodies) should be ordered, independent of whether the PT and aPTT are normal or prolonged. Testing for any of these conditions is not indicated in this patient.
If thrombophilia testing is indicated, evaluation should be based on the circumstances, location, and extent of the thrombosis, possibly with input from a coagulation subspecialist. Factor V Leiden and the prothrombin G20210A mutation are the most common inherited thrombophilias and are associated with a mildly increased risk for VTE.