What medications are recommended for patients post myocardial infarction (MI) and coronary artery bypass graft (CABG)?

Medication Management After Myocardial Infarction and Coronary Artery Bypass Grafting

After myocardial infarction (MI) and coronary artery bypass grafting (CABG), patients should receive aspirin 75-100 mg daily indefinitely, a P2Y12 inhibitor (preferably clopidogrel 75 mg daily) for 12 months, a high-intensity statin, an ACE inhibitor, and a beta-blocker to reduce mortality and improve outcomes. This comprehensive medication regimen is supported by multiple guidelines and has been shown to significantly reduce cardiovascular events and mortality.

Antiplatelet Therapy

Aspirin

• Start aspirin 75-100 mg daily as soon as possible after surgery (within 6 hours postoperatively) and continue indefinitely 1
• Low-dose aspirin (81 mg daily) is preferred over higher maintenance doses to reduce bleeding risk while maintaining efficacy 1

P2Y12 Inhibitors

• For patients with recent MI who undergo CABG, add a P2Y12 inhibitor (preferably clopidogrel 75 mg daily) for 12 months 1, 2
• Clopidogrel is the preferred P2Y12 inhibitor after CABG 1, 2
• Important contraindication: Prasugrel should not be administered to patients with a history of prior stroke or transient ischemic attack 1

Duration of Dual Antiplatelet Therapy (DAPT)

• For patients with MI and CABG: DAPT for 12 months 1
• For patients with CABG only (stable coronary disease): Aspirin monotherapy is standard, but adding clopidogrel may improve vein graft patency 2, 3
• For patients with drug-eluting stents prior to CABG: Continue DAPT for at least 12 months 1

Lipid-Lowering Therapy

• High-intensity statin up to the highest tolerated dose 1
• Target LDL-C level <1.4 mmol/L (55 mg/dL) and ≥50% reduction from baseline 1
• If target not achieved with maximum tolerated statin dose, add ezetimibe 1

Renin-Angiotensin-Aldosterone System Inhibitors

ACE Inhibitors

• Start ACE inhibitors indefinitely in all patients with:
  • LVEF ≤40% 1
  • Hypertension 1
  • Diabetes 1
  • Chronic kidney disease 1
• Consider ACE inhibitors in all other post-MI patients 1

Angiotensin Receptor Blockers (ARBs)

• Use ARBs in patients who are intolerant of ACE inhibitors and have:
  • Heart failure 1
  • LVEF ≤40% 1
  • Hypertension 1

Aldosterone Blockers

• Start aldosterone blockers in patients without significant renal dysfunction or hyperkalemia who:
  • Are already receiving therapeutic doses of an ACE inhibitor and beta-blocker
  • Have LVEF ≤40%
  • Have diabetes or heart failure 1

Beta-Blockers

• Start and continue indefinitely in all post-MI patients unless contraindicated 1
• Use as needed to manage angina, arrhythmias, or blood pressure in all other patients 1

Special Considerations

Patients Requiring Oral Anticoagulation

• For patients with indication for oral anticoagulation (e.g., atrial fibrillation):
  • Direct oral anticoagulant (DOAC) is preferred over vitamin K antagonist (VKA) 1
  • After PCI, early cessation of aspirin (≤1 week) followed by DOAC plus clopidogrel for up to 6-12 months is recommended 1
  • Triple therapy (aspirin + P2Y12 inhibitor + anticoagulant) significantly increases bleeding risk and should be minimized 1

Bleeding Risk Management

• Use proton pump inhibitors in patients at increased risk of gastrointestinal bleeding 1
• Consider lower-dose aspirin (75-81 mg) in patients at higher bleeding risk 1
• Regular assessment for bleeding complications is essential 1

Diabetes Management

• Target HbA1c <7% 1
• Initiate lifestyle modifications and appropriate pharmacotherapy 1

Common Pitfalls and Caveats

1. Underuse of DAPT after CABG: Despite guideline recommendations, DAPT is often underutilized in post-CABG patients, particularly those with recent ACS 4
2. Delayed resumption of antiplatelet therapy: P2Y12 inhibitors should be resumed as soon as deemed safe after surgery 1
3. Inadequate duration of therapy: Premature discontinuation of antiplatelet therapy increases risk of thrombotic events
4. Inappropriate dosing: Using higher than recommended aspirin doses increases bleeding risk without additional benefit 1
5. Failure to assess bleeding risk: Not considering individual bleeding risk can lead to complications, especially with combination antithrombotic therapy

This comprehensive medication regimen has been shown to significantly reduce mortality, recurrent ischemic events, and improve graft patency in patients after MI and CABG. Regular follow-up and monitoring for medication adherence and side effects are essential for optimal outcomes.