Is Dual Antiplatelet Therapy (DAPT) necessary after Coronary Artery Bypass Grafting (CABG)?

DAPT After CABG: Recommendations Based on Clinical Scenario

Dual antiplatelet therapy (DAPT) is generally not recommended after coronary artery bypass grafting (CABG) in patients with stable coronary artery disease (SCAD), but is recommended for 12 months in patients with acute coronary syndrome (ACS). 1

DAPT Recommendations by Clinical Scenario

Stable Coronary Artery Disease (SCAD)

• In patients with SCAD undergoing CABG, there is insufficient data to recommend routine DAPT 1
• DAPT (with clopidogrel initiated early postoperatively) for 12 months after CABG may be reasonable to improve vein graft patency in selected patients at low bleeding risk (Class IIb, Level B-NR recommendation) 1
• Aspirin therapy alone is the standard of care after CABG in SCAD patients 2

Acute Coronary Syndrome (ACS)

• In patients with ACS who undergo CABG, P2Y12 inhibitor therapy should be resumed after CABG to complete 12 months of DAPT therapy (Class I, Level C-LD recommendation) 1
• The default DAPT duration in ACS patients after CABG is 12 months, regardless of revascularization strategy 1
• Six-month therapy duration should be considered in high bleeding risk patients 1

Bleeding Risk Considerations

• The PRECISE-DAPT score can identify CABG patients with increased risk for post-discharge major bleeding with moderate accuracy 3
• For patients at high bleeding risk, a shorter duration of DAPT (6 months) should be considered 1
• In patients with increased bleeding risk (e.g., oral anticoagulation), the benefit/risk ratio may favor shorter-than-recommended duration of DAPT 1

Specific Antiplatelet Recommendations

• Aspirin therapy after CABG improves vein graft patency, particularly during the first postoperative year, and reduces major adverse cardiac events 1
• A daily aspirin dose of 81 mg (range, 75 mg to 100 mg) is recommended (Class I, Level B-NR) 1
• Clopidogrel is considered the default P2Y12 inhibitor when DAPT is indicated after CABG 1
• The use of ticagrelor or prasugrel is generally not recommended as part of triple antithrombotic therapy when oral anticoagulation is required 1

Ongoing Research

• The optimal antiplatelet strategy after CABG in patients with chronic coronary syndromes remains unclear 4
• The ODIN trial is evaluating the effect of short-term DAPT (ticagrelor plus low-dose aspirin) for 1 month after CABG in patients with chronic coronary syndromes 4
• Recent studies suggest that superior outcomes may be attained by combining prasugrel with aspirin, but further research is needed 5

Common Pitfalls and Practical Considerations

• DAPT remains underused in the CABG population, even among patients presenting after ACS, despite guideline recommendations 2
• In patients treated with DAPT after coronary stent implantation who subsequently undergo CABG, P2Y12 inhibitor therapy should be resumed postoperatively to complete the recommended duration of therapy 1
• For patients requiring urgent CABG after treatment with prasugrel, the risk of significant bleeding is substantial, and prasugrel should be discontinued at least 7 days prior to CABG when possible 6
• A proton pump inhibitor is recommended in patients at increased risk of gastrointestinal bleeding for the duration of combined antithrombotic therapy 1

Remember that decisions about treatment with and duration of DAPT require a thoughtful assessment of the benefit/risk ratio, with consideration of both thrombotic and bleeding risks 1.