Treatment Differentials for Acute Myocardial Infarction (AMI)
Primary percutaneous coronary intervention (PCI) is the preferred treatment for ST-elevation myocardial infarction (STEMI) if available within 120 minutes of diagnosis, with immediate transfer to a PCI-capable center recommended for all patients regardless of thrombolysis eligibility. 1
Initial Management
Immediate Interventions
Antiplatelet therapy:
Reperfusion strategy:
Adjunctive pharmacotherapy:
- Intravenous nitroglycerin for 24-48 hours (avoid in hypotension, bradycardia, or excessive tachycardia) 2, 1
- Early intravenous beta-blocker therapy followed by oral therapy (contraindicated in hypotension, acute heart failure, AV block, or severe bradycardia) 2
- Anticoagulation with unfractionated heparin during primary PCI 1
Treatment Based on AMI Type
STEMI Management
Primary PCI approach:
Fibrinolytic approach (when PCI not available within 120 minutes):
Non-STEMI/Unstable Angina Management
- Dual antiplatelet therapy with aspirin plus P2Y12 inhibitor 1, 4
- Early invasive strategy for high-risk patients 1
- Conservative strategy with selective invasive approach for low-risk patients 1
Management of Complications
Cardiogenic Shock
- Immediate PCI if coronary anatomy is suitable 2
- Emergency CABG if coronary anatomy not suitable for PCI or PCI has failed 2
- Inotropic support for persistent hypotension 2
- Routine intra-aortic balloon pumping is not indicated 2
Heart Failure
- Diuretics (usually IV furosemide) 2
- ACE inhibitors within 24 hours for patients with evidence of heart failure, LV systolic dysfunction, diabetes, or anterior infarct 2
- Beta-blockers for patients with LVEF <40% after stabilization 2
- Mineralocorticoid receptor antagonists (MRAs) for patients with LVEF <40% and heart failure or diabetes 2
Arrhythmias
- Atropine for symptomatic sinus bradycardia or AV block with hypotension 2
- Avoid atropine in type II second-degree AV block or third-degree AV block with new wide QRS 2
- Pacemaker insertion for symptomatic bradycardia not responding to atropine 2
Long-Term Management
Pharmacotherapy
- Aspirin 75-100 mg daily indefinitely 2, 1
- P2Y12 inhibitor (in combination with aspirin) for 12 months 2, 1
- Beta-blockers for patients with heart failure or LVEF <40% 2, 1
- High-intensity statin therapy with LDL-C goal <70 mg/dL 2, 1
- ACE inhibitors (or ARBs if intolerant) for patients with heart failure, LV dysfunction, diabetes, or anterior infarct 2, 1
- Proton pump inhibitors for patients at high risk of gastrointestinal bleeding on DAPT 2
Lifestyle Modifications
- Smoking cessation with support, nicotine replacement therapies, varenicline, and bupropion 2
- Participation in cardiac rehabilitation program 2, 1
- Regular physical activity 1
- Diet low in saturated fat and cholesterol 2
Monitoring and Follow-up
- Echocardiography during hospital stay to assess LV and RV function 2
- Exercise testing before discharge (submaximal at 4-7 days or symptom-limited at 10-14 days) 2
- Regular monitoring of cardiac symptoms and medication adherence 1
- Periodic assessment of ventricular function 1
Common Pitfalls and Caveats
- Delayed reperfusion increases mortality in a continuous and non-linear fashion 1
- Calcium channel blockers have not been shown to reduce mortality in AMI patients and may be harmful in certain cases 2
- Nitroglycerin should not be used as a substitute for narcotic analgesics 2
- CYP2C19 poor metabolizers may have reduced effectiveness with clopidogrel 4
- Patients with recurrent chest pain due to pericarditis should receive high-dose aspirin (650 mg every 4-6 hours) rather than increasing anticoagulation 2