Aspirin and Clopidogrel After Quadruple Bypass Surgery
Yes, you need aspirin after CABG, but clopidogrel (dual antiplatelet therapy) is generally not routinely recommended unless specific high-risk features are present.
Aspirin After CABG: Essential and Lifelong
Aspirin 75-162 mg daily should be initiated within 6-48 hours post-operatively (as soon as bleeding concerns resolve) and continued indefinitely. 1
Timing and Dosing
- Start aspirin within 6-24 hours after surgery when there is no concern over bleeding 1
- Aspirin started within 48 hours post-CABG reduces mortality, MI, stroke, renal failure, and bowel infarction 1
- The benefit on saphenous vein graft (SVG) patency is lost if aspirin is delayed beyond 48 hours 1
- Recommended dose: 75-162 mg daily, continued lifelong 1
- Doses of 100-325 mg daily have shown efficacy for graft patency, though lower doses (75-100 mg) are preferred long-term to minimize bleeding risk 1
Evidence for Aspirin Benefit
- Aspirin significantly improves SVG patency rates, particularly during the first postoperative year 1
- Reduces overall mortality without increasing reoperation rates for bleeding 1
- The ATACAS trial showed aspirin started 1-2 hours pre-CABG and resumed within 24 hours post-CABG did not increase bleeding requiring reoperation 1
Clopidogrel After CABG: Not Routinely Recommended
Clopidogrel is NOT part of standard post-CABG therapy unless specific high-risk conditions exist. 1
When Clopidogrel May Be Considered
Dual antiplatelet therapy (aspirin + clopidogrel) may be considered only in selected patients at greater risk of graft occlusion and at low bleeding risk 1:
- Complex grafting procedures (e.g., multiple sequential grafts, poor target vessels)
- Prior history of graft failure
- Suboptimal surgical result
- High thrombotic risk features
Evidence Against Routine Dual Antiplatelet Therapy
- The CURE trial subanalysis showed clopidogrel benefit occurred primarily before CABG surgery, not after 1
- After CABG, no demonstrable difference in primary endpoints was found between clopidogrel and placebo groups 1
- Clopidogrel given within 5 days before CABG increases major bleeding by 50% and transfusion requirements by 70% 1
If Clopidogrel Was Used Pre-operatively
- Should have been stopped at least 5 days before elective CABG to minimize bleeding 1
- Can be restarted post-operatively if there was a specific indication (e.g., recent acute coronary syndrome, drug-eluting stent within past year) 1
- If restarted, continue for the duration indicated by the original indication (typically 12 months for ACS) 1
Special Circumstances Requiring Dual Antiplatelet Therapy
Recent Acute Coronary Syndrome
- If CABG was performed for recent MI or unstable angina, consider continuing clopidogrel 75 mg daily for up to 12 months in addition to aspirin 1
Recent Coronary Stenting Before CABG
- If drug-eluting stent placed <12 months before CABG: Continue dual antiplatelet therapy for at least 12 months total from stent placement 1
- If bare metal stent placed <1 month before CABG: Continue dual antiplatelet therapy for at least 1 month total from stent placement 1
Practical Algorithm
All CABG patients: Start aspirin 75-162 mg within 6-24 hours post-op, continue lifelong 1
Assess for high-risk features:
- Recent ACS (within 1 year)?
- Recent coronary stent (within timeframes above)?
- Complex grafting with poor targets?
- Prior graft failure?
If YES to high-risk features AND low bleeding risk: Add clopidogrel 75 mg daily for specified duration 1
If NO to high-risk features: Aspirin monotherapy only 1
Important Caveats
- Proton pump inhibitor should be added when using dual antiplatelet therapy to reduce GI bleeding risk 1
- Enteric-coated aspirin may result in suboptimal platelet inhibition; soluble aspirin may be preferred at low doses 1
- Monitor for bleeding complications, particularly in first 48 hours when aspirin is initiated 1
- Never discontinue aspirin long-term after CABG unless life-threatening bleeding occurs 1