Is there an indication for Plavix (clopidogrel) two years after Coronary Artery Bypass Grafting (CABG)?

Clopidogrel (Plavix) Use Two Years After CABG

Clopidogrel is not indicated for routine use two years after coronary artery bypass grafting (CABG) in the absence of other compelling indications. 1

Evidence-Based Recommendation

The 2016 ACC/AHA guidelines on dual antiplatelet therapy (DAPT) provide clear direction regarding antiplatelet therapy following CABG:

• For patients with stable ischemic heart disease (SIHD) who underwent CABG, DAPT with clopidogrel is only recommended for 12 months post-operatively to improve vein graft patency (Class IIb recommendation) 1
• Beyond 12 months after CABG, there is no evidence supporting continued clopidogrel therapy in the absence of other indications 1

Clinical Decision Algorithm

1. Assess time since CABG:

   • If >12 months post-CABG (as in this case at 2 years), clopidogrel is not routinely indicated

2. Evaluate for other potential indications for clopidogrel:

   • Recent acute coronary syndrome (ACS) within past 1-3 years
   • Recent percutaneous coronary intervention (PCI) with stent placement
   • Aspirin intolerance or allergy
   • Peripheral arterial disease

3. If none of these indications exist:

   • Discontinue clopidogrel
   • Continue aspirin monotherapy indefinitely (75-100mg daily) 1

Important Considerations

Vein Graft Patency

The primary rationale for DAPT after CABG is to improve vein graft patency. However, this benefit is primarily seen within the first 12 months after surgery. The 2016 ACC/AHA guidelines state: "In patients with SIHD, treatment with DAPT (with clopidogrel initiated early postoperatively) for 12 months after CABG may be reasonable to improve vein graft patency" (Class IIb recommendation) 1.

Bleeding Risk vs. Ischemic Benefit

Continuing DAPT beyond 12 months increases bleeding risk without clear evidence of additional benefit for graft patency. A 2013 study showed that clopidogrel use was not associated with better 5-year outcomes following CABG 2.

Special Circumstances

If the patient had CABG following an acute coronary syndrome (ACS), the guidelines suggest that DAPT may be reasonable for 1-3 years after the ACS event in selected patients who have tolerated DAPT without bleeding complications 1. However, this recommendation is based on the ACS indication rather than the CABG itself.

Common Pitfalls to Avoid

1. Continuing DAPT indefinitely without clear indication: This increases bleeding risk without proven benefit.

2. Abrupt discontinuation without consideration of other indications: Always assess if there are other reasons the patient might need clopidogrel (e.g., recent PCI, peripheral arterial disease).

3. Failure to maintain aspirin therapy: Even when clopidogrel is discontinued, aspirin therapy (75-100mg daily) should generally be continued indefinitely after CABG 1.

4. Overlooking aspirin alternatives: For patients who cannot tolerate aspirin, clopidogrel monotherapy is a reasonable alternative for long-term therapy 1.

In conclusion, for a patient two years post-CABG without other compelling indications, clopidogrel therapy should be discontinued while maintaining aspirin monotherapy for long-term secondary prevention.