What to do for a patient on aspirin and clopidogrel for ACS who now requires apixaban for pulmonary embolism?

Management of Anticoagulation for ACS Patient Who Develops Pulmonary Embolism

For a patient on 75mg aspirin and clopidogrel due to ACS who requires apixaban 10mg BD for pulmonary embolism, the optimal approach is to discontinue aspirin, continue clopidogrel, and add apixaban at the prescribed dose. 1

Rationale for Recommended Approach

The management of patients requiring both antiplatelet therapy for ACS and anticoagulation for venous thromboembolism requires careful consideration of both thrombotic and bleeding risks. The 2021 ACC expert consensus provides clear guidance for this scenario:

Key Considerations:

• Triple therapy (dual antiplatelet therapy plus anticoagulation) significantly increases bleeding risk without providing additional thrombotic protection
• The timing of the ACS event is critical in determining the optimal regimen

Management Algorithm:

1. If ACS occurred <12 months ago:

   • Stop aspirin
   • Continue clopidogrel (P2Y12 inhibitor)
   • Add apixaban 10mg BD for pulmonary embolism 1

2. If ACS occurred >12 months ago:

   • Stop both aspirin and clopidogrel
   • Use apixaban 10mg BD alone 1

Evidence Supporting This Approach

The 2021 ACC expert consensus pathway clearly states that for patients with a history of ACS who are on DAPT and develop a condition requiring anticoagulation (such as pulmonary embolism), the recommended approach is to:

• If <12 months since ACS: "Stop aspirin, continue the P2Y12 inhibitor (with preference given to clopidogrel), and start an OAC (with preference given to a DOAC)" 1
• If >12 months since ACS: "APT may be stopped and most patients can be treated with an OAC alone" 1

This approach is supported by evidence showing that dual therapy with a P2Y12 inhibitor plus anticoagulation provides similar protection against thrombotic events compared to triple therapy, with a significant reduction in bleeding risk 2.

Important Considerations and Monitoring

• Bleeding risk assessment: Regular monitoring for signs of bleeding is essential, as even dual therapy carries increased bleeding risk compared to single therapy
• Duration of therapy: The P2Y12 inhibitor (clopidogrel) should be continued for a total of 12 months from the ACS event 1
• Dosing of apixaban: Ensure the 10mg BD dose is appropriate based on patient characteristics:
  • Consider dose reduction to 2.5mg BD if patient meets at least 2 of: age ≥80 years, weight ≤60kg, or serum creatinine ≥1.5mg/dL 1

Common Pitfalls to Avoid

1. Continuing triple therapy: Adding apixaban to both aspirin and clopidogrel significantly increases bleeding risk without providing additional thrombotic protection 2

2. Discontinuing all antiplatelet therapy too early: If the ACS event was recent (<12 months), maintaining one antiplatelet agent (preferably clopidogrel) is important for preventing stent thrombosis 1

3. Using inappropriate anticoagulant dosing: Ensure the apixaban dose is appropriate for the patient's characteristics and renal function

4. Failing to reassess therapy: The need for continued antiplatelet therapy should be reassessed regularly, particularly once 12 months have passed since the ACS event

By following this evidence-based approach, you can effectively manage both the pulmonary embolism and ACS while minimizing the risk of bleeding complications.