What is the recommended antiplatelet therapy for a patient 4 weeks post Coronary Artery Bypass Graft (CABG) surgery?

Antiplatelet Therapy Recommendations for Post-CABG Patients at 4 Weeks

For patients 4 weeks post-CABG surgery, dual antiplatelet therapy (DAPT) with aspirin 81 mg daily and clopidogrel 75 mg daily is recommended to continue for a total of 12 months after surgery to improve vein graft patency and reduce mortality. 1

General Recommendations Based on Clinical Scenario

For Patients with Stable Ischemic Heart Disease (SIHD)

• DAPT with aspirin 81 mg daily and clopidogrel 75 mg daily for 12 months after CABG is reasonable to improve vein graft patency 1
• Aspirin therapy should be continued indefinitely in all patients with coronary artery disease 1
• Low-dose aspirin (75-100 mg daily) is preferred over higher doses to minimize bleeding risk while maintaining efficacy 1

For Patients with Recent Acute Coronary Syndrome (ACS)

• P2Y12 inhibitor therapy should be resumed after CABG to complete a full 12 months of DAPT therapy after the ACS event 1
• For ACS patients who underwent CABG, continuing DAPT for 12 months is associated with significantly fewer deaths compared to aspirin alone 1

Evidence Supporting DAPT After CABG

• Recent meta-analysis shows DAPT compared to single antiplatelet therapy (SAPT) is associated with significantly lower all-cause mortality (OR 0.65) and cardiovascular mortality (OR 0.53) 2
• DAPT improves vein graft patency rates, particularly during the first postoperative year 1, 3
• The only randomized controlled trial demonstrating benefit showed significantly higher vein graft patency at 3 months in patients treated with clopidogrel and aspirin versus aspirin monotherapy 1

Important Considerations

Bleeding Risk Assessment

• DAPT is associated with higher rates of major bleeding (OR 1.30) and minor bleeding (OR 1.87) compared to SAPT 2
• In patients who develop high bleeding risk (e.g., requiring oral anticoagulation) or significant overt bleeding, discontinuation of P2Y12 inhibitor therapy may be reasonable 1

Duration of Therapy Based on Clinical Context

• Duration of DAPT can vary from as little as 4 weeks to >12 months depending on clinical setting and bleeding risk 1
• For patients who had a coronary stent placed or ACS before CABG, P2Y12 inhibitor therapy should be resumed post-operatively to complete the recommended duration 1, 4

Special Situations

Off-Pump CABG

• DAPT may have significant protective effects in patients who underwent off-pump CABG 5, 4

Patients Requiring Anticoagulation

• For patients requiring oral anticoagulation who are <1 year post-CABG, consider stopping aspirin and continuing clopidogrel along with anticoagulation 1
• For patients >1 year post-CABG requiring anticoagulation, antiplatelet therapy may be stopped and most patients can be treated with anticoagulation alone 1

Common Pitfalls to Avoid

• Discontinuing DAPT too early (before 12 months) in post-CABG patients without compelling reasons, which may increase risk of graft occlusion 1, 6
• Using high-dose aspirin (>100 mg daily), which increases bleeding risk without additional antithrombotic benefit 1
• Failing to resume P2Y12 inhibitor therapy after CABG in patients with recent ACS or PCI 1

Remember that at 4 weeks post-CABG, you are still early in the recommended 12-month DAPT course, and continuing this therapy is supported by guidelines to improve graft patency and clinical outcomes.