For an adult who survived an acute myocardial infarction, what secondary‑prevention medications should a primary care physician prescribe and how long should each be continued?

Post-MI Secondary Prevention Medication Regimen

Every adult who survives a myocardial infarction should be prescribed four core medications indefinitely: aspirin 75-100 mg daily, a P2Y12 inhibitor for 12 months, a high-intensity statin lifelong, and a beta-blocker for at least 3 years (often continued indefinitely), plus an ACE inhibitor if there is left ventricular dysfunction, heart failure, diabetes, or hypertension. 1, 2

Core Medication Classes and Duration

Antiplatelet Therapy

Aspirin:

• Start with 150-325 mg loading dose immediately, then reduce to 75-100 mg daily after the first month and continue indefinitely 1, 2
• Low-dose aspirin (75-100 mg) provides equivalent anti-ischemic benefit with fewer adverse events compared to higher doses 1
• This is a Class I, Level A recommendation with lifelong continuation 1

P2Y12 Inhibitor (Dual Antiplatelet Therapy - DAPT):

• Continue for exactly 12 months after MI with PCI 1, 2
• Ticagrelor 90 mg twice daily is preferred for all moderate-to-high risk patients (those with elevated troponins), regardless of whether they underwent PCI 2
• Prasugrel 10 mg daily is an alternative if PCI was performed and coronary anatomy is known 2
• Clopidogrel 75 mg daily is reserved for patients who cannot tolerate ticagrelor or prasugrel, or who require oral anticoagulation 1, 2
• After 12 months, discontinue the P2Y12 inhibitor and continue aspirin monotherapy 1

Important caveat: In patients at high bleeding risk but not high ischemic risk, DAPT can be shortened to 1-3 months after PCI, then continue with single antiplatelet therapy 1

Statin Therapy

High-intensity statin initiated immediately and continued lifelong 2, 3

• Atorvastatin 40-80 mg daily is the preferred agent 3
• Target LDL-C <1.8 mmol/L (70 mg/dL) or at least 50% reduction from baseline 3
• This is a Class I recommendation with strong mortality benefit 2

Beta-Blocker Therapy

Continue for a minimum of 3 years, often indefinitely 4

• Preferred agents: bisoprolol, carvedilol, or extended-release metoprolol succinate 1, 4
• These provide 20-25% reduction in reinfarction and significant mortality benefit 4
• Greatest benefit in patients with heart failure, left ventricular systolic dysfunction, or ventricular arrhythmias 4
• Many experts recommend indefinite continuation, particularly if hypertension or heart failure is present 4

ACE Inhibitor (or ARB)

Initiate early and continue indefinitely if any of the following are present: 1, 3

• Left ventricular systolic dysfunction (LVEF <40%)
• Heart failure
• Diabetes mellitus
• Hypertension
• Anterior MI

The polypill concept (aspirin + ACE inhibitor + statin) has shown improved adherence compared to separate medications 1

Special Considerations and Common Pitfalls

Bleeding Risk Management

• Add a proton pump inhibitor for gastric protection in patients at increased bleeding risk: elderly, history of GI bleeding, chronic NSAID/steroid use, or on combination antithrombotic therapy 1
• Avoid omeprazole and esomeprazole with clopidogrel due to CYP2C19 inhibition, though clinical significance remains debated 1, 3

Premature Discontinuation

• The greatest drop in medication adherence occurs within the first year post-MI 5
• Patient education must begin immediately after infarction to prevent premature discontinuation 5
• Never stop DAPT prematurely in stented patients—this dramatically increases stent thrombosis risk 3

Patients Requiring Anticoagulation

• If atrial fibrillation or other indication for oral anticoagulation exists, use oral anticoagulant alone (preferably DOAC) plus clopidogrel 75 mg daily, omitting aspirin to reduce bleeding risk 1
• DAPT duration should be minimized (1-3 months) in this population 1

Drug Interactions

• Avoid NSAIDs, particularly ibuprofen, which blocks aspirin's antiplatelet effects 3
• Never use nitrates with phosphodiesterase-5 inhibitors due to severe hypotension risk 3

Algorithm Summary

Month 1:

• Aspirin 150-325 mg daily
• P2Y12 inhibitor (ticagrelor preferred)
• High-intensity statin
• Beta-blocker
• ACE inhibitor (if indicated)

Months 2-12:

• Aspirin 75-100 mg daily
• P2Y12 inhibitor (continue)
• High-intensity statin
• Beta-blocker
• ACE inhibitor (if indicated)

After 12 months:

• Aspirin 75-100 mg daily (indefinitely)
• Discontinue P2Y12 inhibitor (unless high ischemic risk and low bleeding risk, then consider extended therapy with ticagrelor 60 mg twice daily) 1
• High-intensity statin (indefinitely)
• Beta-blocker (minimum 3 years, often indefinitely)
• ACE inhibitor (indefinitely if indicated)

After 3 years:

• Continue all medications except beta-blocker may be discontinued if no heart failure, hypertension, or LV dysfunction 4
• However, many clinicians continue beta-blockers indefinitely given the strong evidence for long-term benefit 4