Bridging Anticoagulation in Arterial Antiphospholipid Syndrome
Bridging anticoagulation is NOT required for patients with arterial Antiphospholipid Syndrome (APS) who are not undergoing a procedure or surgery. Continuous anticoagulation therapy should be maintained without interruption in these patients.
Understanding Anticoagulation in Arterial APS
Arterial APS requires long-term anticoagulation due to the high risk of thrombotic recurrence. The standard treatment is:
- Vitamin K antagonists (VKAs) such as warfarin as first-line therapy 1
- Target INR of 2.0-3.0 for most patients 1
- Direct Oral Anticoagulants (DOACs) are generally not recommended for arterial APS due to higher risk of recurrent arterial thrombosis compared to warfarin 1, 2
When Bridging IS Required
Bridging anticoagulation is only necessary when:
- A patient requires temporary interruption of oral anticoagulants for invasive procedures or surgery 1
- The patient has high-risk features such as:
- Mechanical heart valves
- Recent stroke or TIA within 3 months
- Recent venous thromboembolism (<3 months) 1
Bridging Protocol (When Needed for Procedures)
When bridging is required for procedures, the standard protocol includes:
- Discontinue warfarin 5 days before procedure 1
- Initiate unfractionated heparin (UFH) or low molecular weight heparin (LMWH) 3-4 days before procedure 1
- Stop UFH 4-6 hours before procedure or LMWH 24 hours before procedure 1
- Resume oral anticoagulant evening of or day after procedure 1
- Continue bridging until INR reaches therapeutic range 1
Management of Continuous Anticoagulation
For patients with arterial APS not undergoing procedures:
- Maintain continuous anticoagulation without interruption
- Regular INR monitoring (at least monthly when stable) 3
- Target INR 2.0-3.0 for most patients 1
- Consider higher intensity anticoagulation (INR 3.0-4.0) for patients with recurrent thrombosis despite standard therapy 2
- Combination therapy with antiplatelet agents may be more effective than single agents for secondary prevention in APS with arterial thrombosis 2
Monitoring Considerations
Accurate assessment of anticoagulation intensity is essential in APS patients because:
- Lupus anticoagulant can affect phospholipid-dependent coagulation monitoring tests 4
- Regular monitoring helps optimize anticoagulant dosing and minimize risks 4
- For patients on warfarin, INR should be determined at least weekly during initiation and at least monthly when stable 3
Special Situations
- For patients with renal impairment: Dose adjustments are required when using LMWH 1
- For patients with thrombocytopenia: Careful monitoring is needed 4
- For anticoagulant-refractory APS: Consider combination therapy with antiplatelet agents 2
Key Takeaway
The primary focus for arterial APS patients not undergoing procedures should be maintaining continuous therapeutic anticoagulation rather than implementing unnecessary bridging protocols, which would only introduce potential risks without providing benefits.