What is the management of ST-Elevation Myocardial Infarction (STEMI)?

Management of ST-Elevation Myocardial Infarction (STEMI)

Primary percutaneous coronary intervention (PCI) is the preferred reperfusion strategy for STEMI patients when it can be performed within 90 minutes of first medical contact. 1

Initial Assessment and Management

• Immediate measures (first 10 minutes):
  • Obtain 12-lead ECG within 10 minutes of first medical contact
  • Establish continuous ECG monitoring with defibrillator capacity
  • Administer 162-325 mg of aspirin (non-enteric coated, chewed) immediately 1
  • Add loading dose of P2Y12 inhibitor:
    • Preferred: Ticagrelor 180 mg or prasugrel 60 mg
    • Alternative: Clopidogrel 600 mg (especially if contraindications to prasugrel such as prior stroke/TIA) 1, 2
  • Start anticoagulation immediately (options: unfractionated heparin, enoxaparin, or bivalirudin) 1
  • Administer supplemental oxygen if arterial saturation <90% 3

Reperfusion Strategy Decision Algorithm

1. If PCI can be performed within 90 minutes of first medical contact:

   • Proceed directly to primary PCI (preferred strategy) 1
   • For high-risk patients with large infarct area, target ≤60 minutes 1
   • Transfer patients to PCI-capable centers, bypassing emergency departments when possible 1

2. If anticipated time from STEMI diagnosis to PCI exceeds 120 minutes:

   • Administer fibrinolytic therapy immediately (within 30 minutes of first medical contact) 1, 4
   • Transfer for early catheterization (within 24 hours) after fibrinolysis 1
   • For patients presenting within 2 hours of symptom onset with excessive transfer delays, fibrinolytic therapy followed by immediate transfer for rescue PCI if needed 1

Management of Hemodynamic Complications

For Pulmonary Congestion/Heart Failure:

• Administer oxygen to maintain saturation >90% 3
• Give morphine sulfate for pulmonary congestion 3
• Initiate ACE inhibitors with low initial dose (e.g., captopril 1-6.25 mg) unless systolic BP <100 mmHg 3
• Administer nitrates unless systolic BP <100 mmHg 3
• Consider diuretics (furosemide, torsemide, or bumetanide) if volume overload present 3
• Avoid beta-blockers or calcium channel blockers in patients with frank cardiac failure 3, 1
• Perform urgent echocardiography to assess LV/RV function and exclude mechanical complications 3

For Cardiogenic Shock:

• Intra-aortic balloon counterpulsation (IABP) is recommended when shock is not quickly reversed with pharmacological therapy 3
• Consider inotropic and vasopressor agents to maintain adequate perfusion 3
• Early revascularization (PCI or CABG) is recommended for patients <75 years old who develop shock within 36 hours of MI 3

Post-Reperfusion Management

• Continue dual antiplatelet therapy (DAPT) for at least 12 months after PCI 1
  • Prasugrel 10 mg daily (5 mg if ≥75 years or <60 kg) or clopidogrel 75 mg daily 5
  • Note: Clopidogrel may have reduced effectiveness in CYP2C19 poor metabolizers 2
• Initiate beta-blockers before discharge (start with low doses and titrate if heart failure present) 3
• Start statin therapy 1
• Initiate ACE inhibitors for patients with reduced ejection fraction 1
• Consider aldosterone blockade for patients with LVEF ≤0.40 and either symptomatic heart failure or diabetes (if creatinine ≤2.5 mg/dL in men, ≤2.0 mg/dL in women, and potassium ≤5.0 mEq/L) 3

Secondary Prevention

• Smoking cessation counseling
• Weight management and physical activity
• Diabetes management (goal HbA1c <7%)
• Blood pressure control (goal <140/90 mmHg or <130/80 mmHg for CKD or diabetes)
• Refer to cardiac rehabilitation 1

Key Time Targets

• ECG within 10 minutes of first medical contact
• Door-to-balloon time <90 minutes (ideally <60 minutes for high-risk patients)
• Fibrinolysis within 30 minutes of first medical contact (if PCI not available within 120 minutes)
• Early catheterization within 24 hours after fibrinolysis 1, 4

The evidence clearly demonstrates that timely reperfusion is critical for reducing mortality and preserving myocardial function in STEMI patients. Regional STEMI networks with standardized protocols for rapid diagnosis, transfer, and treatment are essential to optimize outcomes 1, 6.