Treatment of Myocardial Infarction vs Coronary Artery Disease
Myocardial infarction (MI) requires immediate reperfusion therapy (primary PCI within 120 minutes or fibrinolysis if PCI unavailable), while stable coronary artery disease (CAD) is managed with optimal medical therapy and selective revascularization based on symptom severity and lesion complexity. 1, 2
Acute Myocardial Infarction Management
Initial Assessment and Triage
- Immediate ECG within 10 minutes of first medical contact 2
- Rapid assessment of vital signs and hemodynamic stability 1
- Oxygen administration only if SaO2 <90% 2
- Pain relief with titrated IV opioids (morphine 2-4 mg IV) 1, 2
- Sublingual nitroglycerin (0.4 mg every 5 minutes, up to 3 doses) for ongoing chest pain 1
Reperfusion Strategy
Primary PCI (preferred if available within 120 minutes of STEMI diagnosis) 1, 2
Fibrinolytic therapy (if PCI not available within 120 minutes) 2
Early Pharmacotherapy
- Beta-blockers: Begin with IV metoprolol (three 5 mg boluses at 2-minute intervals) followed by oral therapy (50 mg every 6 hours for 48 hours, then 100 mg twice daily) if hemodynamically stable 3
- ACE inhibitors: Start within 24 hours in stable patients, especially with anterior MI, heart failure, or reduced ejection fraction 1, 2
- High-intensity statins: Initiate immediately regardless of baseline lipid levels 2, 4
- Dual antiplatelet therapy: Continue for 12 months 1, 2
Monitoring for Complications
- Urgent echocardiography to assess ventricular function and detect mechanical complications 1, 2
- Monitor for arrhythmias, heart failure, cardiogenic shock, and mechanical complications 1
Stable Coronary Artery Disease Management
Pharmacological Therapy
- Antiplatelet therapy: Daily aspirin (75-162 mg) 1
- Statins: High-intensity therapy to achieve LDL-C <70 mg/dL 1, 4
- Beta-blockers: First-line for symptom relief, especially with prior MI 1
- ACE inhibitors: Recommended for patients with diabetes, hypertension, or reduced ejection fraction 1
- Nitrates: For symptom relief (not shown to reduce mortality) 1
- Calcium channel blockers: Alternative or add-on therapy when beta-blockers are contraindicated or ineffective 1
Revascularization Considerations
- Consider revascularization for:
Key Differences Between MI and CAD Management
| Aspect | Myocardial Infarction | Stable CAD |
|---|---|---|
| Urgency | Immediate intervention | Elective management |
| Initial therapy | Reperfusion (PCI or fibrinolysis) | Optimal medical therapy |
| Antiplatelet | Dual therapy (aspirin + potent P2Y12 inhibitor) | Usually single agent (aspirin) |
| Beta-blockers | IV then oral | Oral only |
| Revascularization | Urgent/emergent | Selective based on symptoms and anatomy |
Long-term Management for Both Conditions
Secondary Prevention
- Smoking cessation 1
- Regular physical activity and cardiac rehabilitation 1, 2
- Blood pressure control (target <130/80 mmHg) 1
- Lipid management with high-intensity statins 4
- Diabetes management 1
- Weight management and healthy diet 1
Follow-up
- Regular monitoring of cardiac symptoms
- Medication adherence assessment
- Periodic assessment of ventricular function, especially after MI 1
- Stress testing or imaging as indicated for recurrent symptoms 1
Common Pitfalls to Avoid
- Delaying reperfusion therapy in MI while waiting for cardiac biomarker results 2
- Using calcium channel blockers as first-line therapy in post-MI patients 2
- Administering beta-blockers to hemodynamically unstable MI patients 1, 2
- Overlooking right ventricular involvement in inferior MI 2
- Inadequate secondary prevention measures after successful treatment 1, 6
Post-MI patients have significantly poorer long-term outcomes compared to stable CAD patients even after successful revascularization, highlighting the importance of aggressive secondary prevention 6.