Antiplatelet Therapy Guidelines for Post-CABG Patients
Aspirin 75-100 mg daily should be initiated within 6 hours postoperatively and continued indefinitely in all patients after CABG surgery to improve graft patency and reduce mortality. 1
Primary Antiplatelet Recommendations
Aspirin Therapy
- Aspirin should be initiated as soon as there is no concern about bleeding, ideally within 6 hours after surgery 1
- Recommended dose: 75-100 mg daily indefinitely 1
- Soluble aspirin may be preferred over enteric-coated formulations, as enteric-coated aspirin has been associated with suboptimal inhibition of platelet aggregation in 44% of patients 1
- When given within 48 hours after CABG, aspirin reduces subsequent rates of mortality, MI, stroke, renal failure, and bowel infarction 1
Alternative for Aspirin-Intolerant Patients
- Clopidogrel 75 mg daily is the recommended alternative for patients who are intolerant of or allergic to aspirin 1
- Ticlopidine is not recommended due to potential life-threatening neutropenia, despite its efficacy at inhibiting platelet aggregation 1
Dual Antiplatelet Therapy (DAPT) Considerations
Standard CABG Patients
- For most patients undergoing isolated CABG without recent ACS or stenting, aspirin monotherapy is the standard approach 1
- DAPT may be considered after CABG in selected patients at greater risk of graft occlusion and at low risk of bleeding 1, 2
Post-ACS CABG Patients
- For patients with recent ACS who undergo CABG, DAPT with aspirin plus a P2Y12 inhibitor for 12 months is recommended 3
- DAPT compared with single antiplatelet therapy is associated with significantly lower all-cause mortality (OR 0.65), cardiovascular mortality (OR 0.53), and major adverse cardiac and cerebrovascular events (OR 0.68) 2
Post-PCI/Stent CABG Patients
- For patients with recent PCI/stent who undergo CABG, resuming P2Y12 inhibitor postoperatively and continuing DAPT until the recommended duration of therapy after PCI is completed 3
P2Y12 Inhibitor Selection
- Clopidogrel is the preferred P2Y12 inhibitor after CABG when DAPT is indicated 1, 3
- Recent evidence suggests that ticagrelor or prasugrel with aspirin may provide superior outcomes compared to clopidogrel with aspirin, with significantly lower all-cause mortality (OR 0.43) and cardiovascular mortality (OR 0.44) 2
- Prasugrel is contraindicated in patients with prior stroke/TIA 4
Bleeding Risk Management
- DAPT increases bleeding risk compared to aspirin alone (OR 1.30 for major bleeding, OR 1.87 for minor bleeding) 2
- A proton pump inhibitor is recommended in patients at increased risk of gastrointestinal bleeding for the duration of antiplatelet therapy 1
- For patients requiring oral anticoagulation, DOAC (unless contraindicated) is recommended in preference to VKA 1
- The use of ticagrelor or prasugrel is generally not recommended as part of triple antithrombotic therapy with aspirin and an oral anticoagulant 1
Timing Considerations for Surgery After P2Y12 Inhibitors
- When possible, delay CABG after P2Y12 inhibitor discontinuation:
Common Pitfalls and Caveats
- Delaying aspirin initiation beyond 48 hours after CABG results in loss of graft patency benefit 1
- Dipyridamole and warfarin add nothing to the effect of aspirin on SVG patency and may increase bleeding risk 1
- Enteric-coated aspirin may provide suboptimal platelet inhibition; soluble aspirin may be preferred 1
- Despite the potential benefits of DAPT, the increased bleeding risk must be carefully considered, especially in elderly patients or those with low body weight 2
The evidence clearly supports aspirin as the cornerstone of antiplatelet therapy after CABG, with consideration of DAPT in specific high-risk populations. The decision to use DAPT should balance the reduced risk of graft occlusion and ischemic events against the increased risk of bleeding complications.