Post-Myocardial Infarction Medication Regimen and Duration
Every patient discharged after myocardial infarction should receive indefinite aspirin (75–100 mg daily), dual antiplatelet therapy for 12 months, high-intensity statin therapy targeting LDL-C <70 mg/dL, an oral beta-blocker (minimum 3 years, preferably indefinitely), and an ACE inhibitor (indefinitely), with enrollment in cardiac rehabilitation. 1, 2
Core Medication Regimen
Antiplatelet Therapy
Aspirin:
- Start immediately with aspirin 162–325 mg on day 1, then continue indefinitely at 75–162 mg daily (preferably 75–100 mg to minimize bleeding risk). 1, 2
- Low-dose aspirin (75–100 mg) provides equivalent cardiovascular protection with fewer adverse events compared to higher doses. 1, 2
- If true aspirin allergy exists, substitute clopidogrel 75 mg daily indefinitely. 1, 2
Dual Antiplatelet Therapy (DAPT):
- Continue for exactly 12 months after MI with aspirin plus a P2Y12 inhibitor (ticagrelor, prasugrel, or clopidogrel). 1, 3, 2
- This 12-month duration applies regardless of whether the patient received PCI, fibrinolytic therapy, or medical management alone. 3
- After PCI with stenting, minimum durations are: bare-metal stent (1 month, ideally 12 months), drug-eluting stent (12 months). 1, 4, 3
- After 12 months, transition to aspirin monotherapy indefinitely. 1, 2
Beta-Blocker Therapy
- Start within the first 24 hours in hemodynamically stable patients and continue indefinitely (minimum 3 years). 1, 2
- Beta-blockers are particularly critical for patients with heart failure or LVEF <40%, but all post-MI patients benefit. 1, 2
- Avoid intravenous beta-blockers in patients with hypotension, acute heart failure, AV block, or severe bradycardia. 1
- Evidence supports indefinite use; the 20–25% reduction in mortality and reinfarction persists long-term. 1
ACE Inhibitor (or ARB) Therapy
- Initiate within 24 hours for all patients with anterior MI, heart failure, LVEF ≤40%, diabetes, or hypertension, and continue indefinitely. 1, 2
- Consider ACE inhibitors for all other post-MI patients even without these high-risk features. 1, 2
- Start with low doses (e.g., lisinopril 2.5–5 mg) and titrate upward as tolerated. 2
- For ACE inhibitor-intolerant patients, substitute an ARB (preferably valsartan). 1, 2
Aldosterone Antagonist:
- Add when LVEF ≤40% with symptomatic heart failure or diabetes, provided serum creatinine is ≤2.5 mg/dL (men) or ≤2.0 mg/dL (women) and potassium is ≤5.0 mEq/L. 1, 2
High-Intensity Statin Therapy
- Start as early as possible during the index hospitalization and maintain indefinitely. 1, 2
- Target LDL-C <70 mg/dL (1.8 mmol/L) or achieve ≥50% reduction if baseline LDL-C is 70–135 mg/dL. 1, 2
- High-intensity statins (e.g., atorvastatin 40–80 mg or rosuvastatin 20–40 mg) are preferred. 1
Duration Summary by Medication Class
| Medication | Duration | Key Points |
|---|---|---|
| Aspirin | Indefinitely | 75–100 mg daily after initial loading [1,2] |
| P2Y12 inhibitor | 12 months | Then discontinue; aspirin continues [1,3,2] |
| Beta-blocker | Indefinitely (minimum 3 years) | Especially critical if LVEF <40% [1,2] |
| ACE inhibitor/ARB | Indefinitely | Start within 24 hours [1,2] |
| Statin | Indefinitely | High-intensity, target LDL-C <70 mg/dL [1,2] |
| Aldosterone antagonist | Indefinitely | If LVEF ≤40% + HF or DM [1,2] |
Special Considerations
Anticoagulation
- Add warfarin (target INR 2.0–3.0) only for specific indications: atrial fibrillation, left ventricular thrombus, or extensive wall-motion abnormalities. 1, 2
- When combining warfarin with DAPT (triple therapy), target INR 2.0–2.5 and use low-dose aspirin (75–81 mg) to reduce bleeding risk. 1, 2
Proton-Pump Inhibitor
Extended DAPT Beyond 12 Months
- For select high-risk patients who tolerate DAPT without bleeding complications during the first 12 months, continuation beyond 12 months may be reasonable. 1, 3
- Options include aspirin plus ticagrelor 60 mg twice daily or aspirin plus rivaroxaban 2.5 mg twice daily. 1
Surgical Timing
- If CABG becomes necessary, discontinue clopidogrel ≥5 days before surgery, prasugrel ≥7 days, and ticagrelor ≥5–7 days, unless urgent revascularization benefits outweigh bleeding risks. 1, 3
Non-Pharmacological Interventions
Cardiac Rehabilitation
- Enroll all patients in a structured cardiac rehabilitation program. 1, 2
- Recommend ≥30 minutes of aerobic activity daily (or 3–4 sessions weekly) plus increased daily physical activity. 1, 2
Lifestyle Modifications
- Smoking cessation: Provide repeated counseling with pharmacotherapy (nicotine replacement, varenicline, or bupropion). 1, 2
- Mediterranean diet: Low in saturated fat, high in polyunsaturated fat, fruits, and vegetables; fatty fish ≥2 times weekly. 1
- Weight management: Target BMI 18.5–24.9 kg/m²; waist circumference <40 inches (men) or <35 inches (women). 1
Blood Pressure Control
Diabetes Management
Influenza Vaccination
- Provide annual influenza vaccine to all patients with cardiovascular disease. 2
Critical Pitfalls to Avoid
- Never discontinue DAPT prematurely in the first 12 months without compelling reasons such as life-threatening bleeding or urgent surgery. 3, 2
- Do not use high-dose aspirin (325 mg) for maintenance therapy; 75–100 mg provides equivalent protection with less bleeding. 1, 3, 2
- Do not prescribe prasugrel to patients with prior stroke or TIA (Class III Harm recommendation). 3
- Do not routinely use calcium-channel blockers for long-term secondary prevention after STEMI; they lack mortality benefit. 1, 2
- Premature DAPT discontinuation is the most significant risk factor for stent thrombosis, particularly with drug-eluting stents. 4
- Counsel patients on medication adherence before discharge; treatment adherence drops to approximately 57% after 2 years, which worsens outcomes. 2