What is the management approach for a patient presenting with ST-Elevation Myocardial Infarction (STEMI)?

Management of ST-Elevation Myocardial Infarction (STEMI)

Primary percutaneous coronary intervention (PCI) is the recommended reperfusion strategy for STEMI when it can be performed within 90 minutes of first medical contact by experienced operators at a PCI-capable facility. 1

Initial Assessment and Triage

• Immediate ECG: Obtain 12-lead ECG within 10 minutes of first medical contact 1
• Establish continuous monitoring: Set up ECG monitoring with defibrillator capacity immediately 1
• Oxygen therapy: Administer supplemental oxygen only if arterial saturation <90% 1
• Triage decision: Based on time from symptom onset and anticipated transfer time to PCI-capable facility

Reperfusion Strategy

Primary PCI Pathway

• First medical contact-to-device time ≤90 minutes is the goal for patients directly transported to PCI-capable hospitals 1
• First medical contact-to-device time ≤120 minutes for patients requiring transfer from non-PCI-capable hospitals 1
• Immediate transfer for patients with cardiogenic shock or severe heart failure regardless of time delay from MI onset 1
• Antiplatelet therapy:
  • Loading dose of aspirin 162-325 mg (non-enteric coated, chewed) immediately 1
  • Loading dose of a potent P2Y12 inhibitor: ticagrelor 180 mg or prasugrel 60 mg (preferred over clopidogrel) 1, 2
  • Clopidogrel 600 mg if prasugrel/ticagrelor unavailable or contraindicated 1
• Anticoagulation: Start immediately with unfractionated heparin, enoxaparin, or bivalirudin 1

Fibrinolytic Therapy Pathway

• Indicated when anticipated delay to PCI exceeds 120 minutes from first medical contact 1
• Administer within 30 minutes of first medical contact 3
• Fibrin-specific agent (tenecteplase, alteplase, or reteplase) recommended 3
• Contraindications to fibrinolysis include:
  • Active internal bleeding
  • History of cerebrovascular accident
  • Intracranial/intraspinal surgery or trauma within 2 months
  • Intracranial neoplasm, arteriovenous malformation, or aneurysm
  • Known bleeding diathesis
  • Severe uncontrolled hypertension 4
• Transfer to PCI-capable center immediately after fibrinolysis for early angiography (2-24 hours) 3
• Emergency angiography and rescue PCI if fibrinolysis fails (<50% ST-segment resolution at 60-90 minutes) or if hemodynamic/electrical instability develops 3

Medication Management

Antiplatelet Therapy

• Dual antiplatelet therapy (DAPT) for 12 months after PCI 3, 1
  • Aspirin 75-100 mg daily long-term 3
  • P2Y12 inhibitor (ticagrelor or prasugrel preferred over clopidogrel) 1
  • Proton pump inhibitor recommended with DAPT in patients at high risk of gastrointestinal bleeding 3

Additional Medications

• Beta-blockers: Start before discharge with low doses and titrate if heart failure present; avoid in patients with hypotension, acute heart failure, AV block, or severe bradycardia 3, 1
• ACE inhibitors: Start within 24 hours in patients with heart failure, LV systolic dysfunction, diabetes, or anterior infarct 3
• Statins: High-intensity statin therapy as early as possible 3, 1
• Aldosterone antagonists: Consider for patients with LVEF ≤40% and either symptomatic heart failure or diabetes 1

Management of Complications

• Cardiogenic shock: Immediate transfer to PCI-capable facility regardless of time delay from MI onset 1
• Mechanical complications: Perform urgent echocardiography to assess LV/RV function and exclude mechanical complications 1
• Arrhythmias: Have anti-arrhythmic therapy available for bradycardia and/or ventricular irritability 4
• Heart failure: Consider diuretics (e.g., furosemide) if volume overload present 1

Secondary Prevention

• Cardiac rehabilitation: Refer all patients 3, 1
• Smoking cessation: Provide counseling and pharmacotherapy 3, 1
• Risk factor management:
  • Diabetes management (goal HbA1c <7%)
  • Blood pressure control (goal <140/90 mmHg or <130/80 mmHg for patients with chronic kidney disease or diabetes) 1

Special Considerations

• Elderly patients (≥75 years): Prasugrel generally not recommended except in high-risk patients (diabetes or prior MI) 2
• Low body weight (<60 kg): Consider reduced maintenance dose of prasugrel (5 mg daily) 2
• Prior stroke/TIA: Prasugrel contraindicated; use clopidogrel instead 2
• Planned CABG: When possible, discontinue prasugrel at least 7 days prior to surgery 2

The evidence strongly supports that timely reperfusion is critical in STEMI management, with primary PCI being the preferred strategy when available within the recommended timeframes. When primary PCI cannot be delivered promptly, a pharmacoinvasive approach with immediate fibrinolysis followed by transfer for early angiography represents a reasonable alternative 1, 5.