Management of ST-Elevation Myocardial Infarction (STEMI)
Primary percutaneous coronary intervention (PCI) is the recommended method of reperfusion when it can be performed in a timely fashion by experienced operators within 90 minutes of first medical contact. 1
Initial Assessment and Management
- Perform a 12-lead ECG within 10 minutes of first medical contact 2
- Establish continuous ECG monitoring with defibrillator capacity immediately
- Administer 162-325 mg of aspirin (non-enteric coated, chewed) immediately upon STEMI diagnosis 2
- Administer supplemental oxygen if arterial saturation <90% 2
- Consider morphine for pain relief and pulmonary congestion 2
Reperfusion Strategy Decision Algorithm
Primary PCI Pathway (Preferred)
- Transport directly to a PCI-capable hospital with an ideal first medical contact-to-device time of ≤90 minutes 1
- For patients initially arriving at a non-PCI-capable hospital, immediate transfer to a PCI-capable facility is recommended with a goal first medical contact-to-device time of ≤120 minutes 1
- Add loading dose of a P2Y12 inhibitor:
- Start anticoagulation immediately (unfractionated heparin, enoxaparin, or bivalirudin) 2
Fibrinolysis Pathway
- Indicated when anticipated delay to PCI exceeds 120 minutes from first medical contact 1
- Should be administered within 30 minutes of hospital arrival 1
- Preferably started in pre-hospital setting when appropriate 4
- Contraindications include prior intracranial hemorrhage, known cerebrovascular lesion, recent major trauma/surgery, active bleeding, and suspected aortic dissection 2
- Follow with transfer to a PCI-capable center for:
Special Circumstances
- For patients with cardiogenic shock or severe heart failure: Immediate transfer to PCI-capable facility regardless of time delay from MI onset 1
- For resuscitated out-of-hospital cardiac arrest with STEMI on ECG: Immediate angiography and PCI when indicated 1
- For patients presenting 12-24 hours after symptom onset with clinical/ECG evidence of ongoing ischemia: Primary PCI is reasonable 1
- Therapeutic hypothermia should be initiated as soon as possible in comatose STEMI patients with out-of-hospital cardiac arrest due to VF/VT 1
Adjunctive Pharmacotherapy
- Dual antiplatelet therapy:
- Beta-blockers: Start before discharge (use low doses and titrate if heart failure present) 2
- ACE inhibitors: Initiate with low dose unless systolic BP <100 mmHg 2
- Statins: High-intensity statin therapy 2
- Aldosterone antagonists: Consider for patients with LVEF ≤40% and either symptomatic heart failure or diabetes 2
Post-STEMI Care and Secondary Prevention
- Discontinue NSAIDs (except aspirin) due to increased risks of mortality, reinfarction, and heart failure 1
- Refer to cardiac rehabilitation 2
- Smoking cessation counseling and support 2
- Weight management and physical activity recommendations 2
- Diabetes management (goal HbA1c <7%) 2
- Blood pressure control (goal <140/90 mmHg or <130/80 mmHg for patients with chronic kidney disease or diabetes) 2
Monitoring for Complications
- Perform echocardiography to assess LV/RV function and exclude mechanical complications 2
- Monitor for right ventricular failure (hypotension, clear lung fields, elevated jugular venous pressure) 2
- Assess for ventricular septal rupture (new systolic murmur) 2
- Avoid beta-blockers in hypotensive patients or those with signs of heart failure 2
The most critical factor in STEMI management is minimizing the time from symptom onset to reperfusion therapy. A well-coordinated system of care with standardized protocols for rapid diagnosis, transfer, and treatment is essential to optimize outcomes and can prevent 6-8 events per 100 patients 2.