What is the management strategy for 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 by an experienced team within 120 minutes of STEMI diagnosis; if this timeline cannot be met, immediate fibrinolytic therapy should be administered within 30 minutes of first medical contact. 1, 2

Initial Diagnosis and Assessment

• Twelve-lead ECG recording and interpretation should be obtained as soon as possible at first medical contact, with a maximum target delay of 10 minutes 1, 2
• ECG monitoring with defibrillator capacity should be initiated immediately in all patients with suspected STEMI 1, 2
• Routine oxygen therapy is not recommended in patients with oxygen saturation ≥90% 1, 2
• Aspirin (oral 150-325 mg or IV 250-500 mg if unable to swallow) should be administered as soon as possible to all patients without contraindications 1, 2

Reperfusion Strategy Selection

• The decision between primary PCI and fibrinolysis depends on time from STEMI diagnosis to anticipated reperfusion 1, 2:
  • If anticipated time to PCI-mediated reperfusion is ≤120 minutes → Primary PCI
  • If anticipated time to PCI-mediated reperfusion is >120 minutes → Immediate fibrinolysis

Primary PCI Strategy

• Patients should be transferred directly to the catheterization laboratory, bypassing the emergency department 1, 2
• PCI-capable centers should deliver 24/7 service and perform primary PCI without delay 1, 2
• Antithrombotic therapy for primary PCI 1, 2, 3:
  • Aspirin (150-325 mg orally or 250-500 mg IV)
  • A potent P2Y12 inhibitor (prasugrel or ticagrelor preferred over clopidogrel) administered before or at the time of PCI
  • Anticoagulation with unfractionated heparin (UFH) as an IV bolus at 100 U/kg (60 U/kg if GPIIb/IIIa inhibitors are used)
  • Fondaparinux is not recommended for primary PCI

Fibrinolytic Strategy

• Fibrinolytic therapy should be initiated within 30 minutes of first medical contact when primary PCI cannot be performed within 120 minutes 1, 2
• Preferably administered in the pre-hospital setting if available 1, 2
• A fibrin-specific agent (tenecteplase, alteplase, or reteplase) is recommended 1, 2
• Antithrombotic therapy with fibrinolysis 1, 2:
  • Aspirin (oral or IV)
  • Clopidogrel added to aspirin (prasugrel and ticagrelor are not recommended with fibrinolysis)
  • Anticoagulation (preferably enoxaparin) until revascularization or for the duration of hospital stay (up to 8 days)
• Transfer to a PCI-capable facility after fibrinolysis is recommended (pharmaco-invasive approach) 1, 4

Management of Complications

Cardiogenic Shock

• Intra-aortic balloon counterpulsation is recommended when shock is not quickly reversed with pharmacological therapy 1
• Intra-arterial monitoring is recommended 1
• Early revascularization (PCI or CABG) is recommended for patients <75 years old who develop shock within 36 hours of MI and are suitable for revascularization that can be performed within 18 hours of shock 1
• Vasopressor support should be given for hypotension that does not resolve after volume loading 1
• Echocardiography should be used to evaluate mechanical complications 1

Pulmonary Congestion/Heart Failure

• Oxygen supplementation to arterial saturation >90% is recommended 1
• Morphine sulfate should be given to patients with pulmonary congestion 1
• ACE inhibitors should be given to patients with pulmonary edema unless systolic blood pressure is <100 mmHg or >30 mmHg below baseline 1
• Beta-blockers or calcium channel blockers should not be administered acutely to patients with frank cardiac failure 1

In-Hospital Management

• Routine echocardiography should be performed during hospitalization to assess LV and RV function, detect mechanical complications, and exclude LV thrombus 1, 2
• Dual antiplatelet therapy (DAPT) with aspirin plus a P2Y12 inhibitor should be maintained for 12 months 1, 2
• High-intensity statin therapy should be initiated as early as possible 1, 2
• Beta-blockers should be started orally in patients with heart failure and/or LVEF <40% unless contraindicated 1, 2
• ACE inhibitors should be started within 24 hours in patients with heart failure, LV systolic dysfunction, diabetes, or anterior infarct 1, 2

Post-Discharge Management

• Antiplatelet therapy with low-dose aspirin (75-100 mg) should be continued indefinitely 1, 2
• DAPT should be continued for 12 months after PCI unless there are contraindications 1, 2, 3
• A proton pump inhibitor should be used in combination with DAPT in patients at high risk of gastrointestinal bleeding 1, 2
• LDL-C should be targeted to <70 mg/dL or reduced by at least 50% if baseline is between 70-135 mg/dL 1, 2
• Smoking cessation counseling with pharmacological support should be provided 1, 2
• Participation in a cardiac rehabilitation program is strongly recommended 1, 2

Special Considerations

• Patients with cardiac arrest and an ECG consistent with STEMI should undergo a primary PCI strategy 1, 2
• In patients ≥75 years with shock, early revascularization may be reasonable for selected patients with good prior functional status 1
• Prasugrel should be avoided in patients ≥75 years of age, with history of stroke/TIA, or weight <60 kg due to increased bleeding risk 3
• For patients not undergoing reperfusion, supportive care and secondary prevention medications should still be administered 1, 5