What is the treatment for ST-Elevation Myocardial Infarction (STEMI)?

Treatment for ST-Elevation Myocardial Infarction (STEMI)

Primary percutaneous coronary intervention (PCI) is the recommended first-line treatment for STEMI and should be performed within 90 minutes of first medical contact to reduce mortality and improve outcomes. 1

Initial Assessment and Management

• Perform ECG within 10 minutes of first medical contact
• Administer aspirin immediately (162-325 mg chewed or 75-250 mg IV) 2, 1
• Add a loading dose of a P2Y12 receptor inhibitor as early as possible:
  • Prasugrel 60 mg (preferred if primary PCI is planned and no history of stroke/TIA) 2
  • Ticagrelor 180 mg (alternative option) 1
  • Clopidogrel 600 mg (if prasugrel or ticagrelor contraindicated) 2

Reperfusion Strategy

Primary PCI (Preferred Strategy)

• Indicated for patients with:
  • Ischemic symptoms <12 hours (Class I, Level A) 2
  • Contraindications to fibrinolytic therapy regardless of time delay (Class I, Level B) 2
  • Cardiogenic shock or acute severe heart failure regardless of time from MI onset (Class I, Level B) 2
  • Evidence of ongoing ischemia between 12-24 hours after symptom onset (Class IIa, Level B) 2

Fibrinolytic Therapy

• Administer if PCI cannot be performed within 120 minutes of first medical contact 1
• Should be given within 30 minutes of first medical contact 1
• Options include tenecteplase, alteplase, or reteplase 1, 3
• After fibrinolysis, transfer to a PCI-capable center immediately 1

Anticoagulation During Primary PCI

• Unfractionated heparin (UFH):
  • With GP IIb/IIIa inhibitor: 50-70 U/kg IV bolus 2
  • Without GP IIb/IIIa inhibitor: 70-100 U/kg bolus 2
• Bivalirudin: 0.75 mg/kg IV bolus, then 1.75 mg/kg/h infusion (preferred over UFH with GP IIb/IIIa in patients at high bleeding risk) 2

Adjunctive Therapies During PCI

• Consider glycoprotein IIb/IIIa inhibitors in selected patients:
  • Abciximab, high-bolus-dose tirofiban, or double-bolus eptifibatide (Class IIa, Level A/B) 2
  • May be reasonable to administer in pre-catheterization laboratory setting (Class IIb, Level B) 2
  • Intracoronary abciximab may be considered (Class IIb, Level B) 2
• Stent placement (bare-metal or drug-eluting) is useful (Class I, Level A) 2
  • Bare-metal stents should be used in patients with high bleeding risk or inability to comply with prolonged DAPT 2

Post-PCI Antithrombotic Therapy

• Aspirin:
  • Continue indefinitely (Class I, Level A) 2
  • 81 mg daily is preferred over higher maintenance doses (Class IIa, Level B) 2, 4
• P2Y12 inhibitor:
  • Continue for at least 12 months after DES placement 2
  • For BMS, continue for at least 30 days and up to 1 year 2
  • Prasugrel 10 mg daily (5 mg if ≥75 years or <60 kg) 2
  • Ticagrelor 90 mg twice daily 1
  • Clopidogrel 75 mg daily (if prasugrel or ticagrelor contraindicated) 2

Management of Cardiogenic Shock

• Emergency revascularization with PCI or CABG is recommended regardless of time delay from MI onset (Class I, Level B) 2
• Intra-aortic balloon pump counterpulsation can be useful for patients who don't quickly stabilize with pharmacological therapy (Class IIa, Level B) 2
• Alternative LV assist devices may be considered in refractory shock (Class IIb, Level C) 2

Secondary Prevention Medications

• High-intensity statin therapy (Class I, Level B) 2
• ACE inhibitor within 24 hours for patients with:
  • Heart failure
  • LV systolic dysfunction (LVEF <40%)
  • Diabetes
  • Anterior infarct 2, 1
• Beta-blocker within 24 hours for patients with heart failure and/or LVEF <40% 1
• Mineralocorticoid receptor antagonist for patients with LVEF ≤40% and heart failure or diabetes 2, 1

Common Pitfalls and Caveats

• Avoid prasugrel in patients with prior stroke/TIA (Class III: Harm, Level B) 2
• Drug-eluting stents should not be used in patients unable to comply with prolonged DAPT (Class III: Harm, Level B) 2
• Fondaparinux is not recommended as sole anticoagulant for primary PCI (Class III: Harm, Level B) 2
• Avoid PCI of a non-infarct artery at the time of primary PCI in patients without hemodynamic compromise (Class III: Harm, Level B) 2
• Avoid intravenous beta-blockers in patients with hypotension, acute heart failure, AV block, or severe bradycardia 1

The treatment of STEMI requires rapid assessment and decision-making, with the goal of achieving reperfusion as quickly as possible to minimize myocardial damage and improve survival. The choice between primary PCI and fibrinolysis depends on the availability of PCI facilities and the anticipated time to reperfusion, with primary PCI being the preferred strategy when feasible within the recommended timeframes.