Can a hypercoagulable workup be done in a patient already on Eliquis (apixaban)?

Hypercoagulable Workup in Patients on Apixaban (Eliquis)

Yes, a hypercoagulable workup can be performed while a patient is on Eliquis (apixaban), but certain tests will be affected by the anticoagulant and may yield false results, while others remain reliable.

Tests Affected by Apixaban

• Significantly affected tests (may give unreliable results) 1:
  • Prothrombin time (PT)
  • Activated partial thromboplastin time (aPTT)
  • Anti-factor Xa activity assays
  • Thrombin generation tests

Tests Minimally Affected by Apixaban

• Reliable tests that can be performed while on apixaban 1:
  • Antithrombin III activity
  • Protein C and S antigen levels
  • Factor V Leiden genetic testing
  • Prothrombin gene mutation testing
  • Antiphospholipid antibody testing

Management Options for Comprehensive Testing

For patients requiring a complete hypercoagulable workup including tests affected by apixaban, there are two approaches:

Option 1: Temporary Discontinuation of Apixaban

If clinically safe and the patient is at low thrombotic risk:

1. Consult with the prescribing physician
2. Temporarily discontinue apixaban for 3-5 days to allow drug clearance
3. Perform comprehensive testing
4. Resume apixaban promptly after testing 1

Option 2: Bridging Therapy for High-Risk Patients

For patients with high thrombotic risk (recent thrombosis or multiple prior events):

1. Switch from apixaban to a short-acting parenteral anticoagulant
2. Options include:
   • Argatroban (very short half-life)
   • Fondaparinux
3. Perform testing while on bridging therapy
4. Resume apixaban after testing 1

Important Considerations

• Risk assessment: Evaluate the patient's thrombotic risk before making any changes to anticoagulation
• Timing: If possible, schedule the hypercoagulable workup before initiating anticoagulation
• Interpretation: When interpreting results, consider the potential impact of apixaban on test results
• Documentation: Clearly document the patient's anticoagulation status at the time of testing

Pitfalls to Avoid

• Never discontinue anticoagulation in high-risk patients without bridging therapy
• Don't interpret functional coagulation assays (PT, aPTT) without considering the impact of apixaban
• Avoid unnecessary testing if results won't change management
• Don't delay testing if clinical suspicion for thrombophilia is high and results would impact long-term management

By carefully selecting appropriate tests and managing anticoagulation appropriately, a meaningful hypercoagulable workup can be performed in patients on apixaban therapy.