Should dual or single antiplatelet therapy (aspirin + clopidogrel) be used after carotid endarterectomy?

Antiplatelet Therapy After Carotid Endarterectomy

Single antiplatelet therapy with aspirin (75-100 mg daily) is recommended after carotid endarterectomy (CEA) for long-term management, with a Class I, Level of Evidence A recommendation. 1

Evidence-Based Recommendations

Standard Approach

• Single antiplatelet therapy is the standard of care after CEA:
  • Aspirin 75-100 mg daily (preferred) 1
  • Alternative options for aspirin-intolerant patients:
    • Clopidogrel 75 mg daily 1
    • Extended-release dipyridamole plus low-dose aspirin (25 mg and 200 mg twice daily) 1

Special Considerations for Symptomatic Patients

• For recently symptomatic patients, the American College of Cardiology and European Society of Cardiology recommend:
  • Dual antiplatelet therapy (DAPT) with aspirin 75-100 mg plus clopidogrel 75 mg daily for 21-30 days after CEA 1
  • Followed by indefinite antiplatelet monotherapy

Benefits and Risks of Antiplatelet Therapy

Benefits

• Antiplatelet drugs significantly reduce stroke risk after CEA (OR 0.58; 95% CI 0.34-0.98) 1
• Dual antiplatelet therapy has been shown to:
  • Reduce post-operative embolization 2
  • Reduce stroke due to early postoperative carotid thrombosis 3
  • Potentially reduce TIA or stroke (0.9% vs 1.6%, p=0.002) 4

Risks

• Dual antiplatelet therapy is associated with:
  • Increased risk of postoperative bleeding requiring reoperation (1.3% vs 0.7%, p=0.004) 4
  • Five-fold increased risk of postoperative bleeding after CEA (OR 5.1; 95% CI 1.8-14.2) 5

Long-term Management

• Beyond the first month after CEA, single antiplatelet therapy should be continued indefinitely for long-term prophylaxis against ischemic cardiovascular events 1
• Lower-dose aspirin (75-100 mg) is preferred over higher doses due to similar efficacy with lower bleeding risk 1

Special Patient Populations

• For patients with both carotid disease and atrial fibrillation requiring oral anticoagulation:
  • Oral anticoagulation alone (preferably with a direct oral anticoagulant) is recommended 1
  • Oral anticoagulation can typically be initiated 3-14 days after surgery 1
  • Combination therapy with antiplatelet agents increases bleeding risk without clear benefit 6

Practical Considerations

• Aspirin should be continued throughout the perioperative period 3
• Aggressive treatment of post-CEA hypertension is critical, particularly in recently symptomatic patients 3
• Routine post-operative surveillance with duplex ultrasound is reasonable at 1 month, 6 months, and annually after CEA 1

In conclusion, while dual antiplatelet therapy may offer neurologic protection in the immediate post-operative period, particularly for symptomatic patients, the evidence strongly supports single antiplatelet therapy for long-term management after CEA to balance stroke prevention with bleeding risk.