From the FDA Drug Label
For patients with a first episode of DVT or PE who have documented antiphospholipid antibodies or who have two or more thrombophilic conditions, treatment for 12 months is recommended and indefinite therapy is suggested For patients with a first episode of DVT or PE who have documented deficiency of antithrombin, deficiency of Protein C or Protein S, or the Factor V Leiden or prothrombin 20210 gene mutation, homocystinemia, or high Factor VIII levels (>90th percentile of normal), treatment for 6 to 12 months is recommended and indefinite therapy is suggested for idiopathic thrombosis
The appropriate workup for a patient with suspected hypercoagulability includes:
- Testing for antiphospholipid antibodies
- Testing for thrombophilic conditions such as:
- Deficiency of antithrombin
- Deficiency of Protein C or Protein S
- Factor V Leiden or prothrombin 20210 gene mutation
- Homocystinemia
- High Factor VIII levels (>90th percentile of normal) The appropriate treatment includes:
- Warfarin therapy for 6 to 12 months or indefinitely, depending on the underlying condition and risk factors
- Target INR of 2.0-3.0 for most patients, but may be adjusted based on individual risk factors and conditions 1
- Dabigatran may not be recommended for patients with triple-positive antiphospholipid syndrome due to increased risk of thrombosis 2
From the Research
The workup for suspected hypercoagulability should begin with a thorough history and physical examination, focusing on personal or family history of thrombosis, pregnancy complications, and autoimmune disorders, as recommended by 3. The evaluation process should be guided by the clinical presentation, suspected pathophysiology, and an understanding of how test results may affect patient care. Key aspects to consider include:
- Personal or family history of thrombosis
- Pregnancy complications
- Autoimmune disorders Laboratory testing should include:
- Complete blood count
- Prothrombin time
- Activated partial thromboplastin time
- Specific tests for inherited and acquired thrombophilias, such as:
- Factor V Leiden mutation
- Prothrombin gene mutation
- Protein C and S deficiency
- Antithrombin deficiency
- Antiphospholipid antibodies
- Homocysteine levels Timing of testing is crucial, as acute thrombosis and anticoagulation can affect results; ideally, testing should occur at least 2-3 weeks after completing anticoagulation therapy, as noted in 4 and 5. Treatment depends on the specific cause and clinical presentation. For acute thrombosis, standard anticoagulation with heparin (unfractionated or low molecular weight) followed by warfarin or direct oral anticoagulants (DOACs) like apixaban, rivaroxaban, or dabigatran is recommended, as suggested by 6 and 3. Duration of anticoagulation varies: 3-6 months for provoked thrombosis, while unprovoked or recurrent events may require indefinite treatment. For pregnant patients with thrombophilia, prophylactic low molecular weight heparin may be indicated, as mentioned in 5. Patients with antiphospholipid syndrome often require long-term warfarin with higher INR targets, as noted in 5. Management should be individualized based on thrombosis risk, bleeding risk, and patient preferences, with regular monitoring of anticoagulation efficacy and potential complications, as emphasized in 3.