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 by an experienced team. 1

Initial Assessment and Management

• Immediate administration of 162-325 mg of non-enteric coated aspirin should be given to all STEMI patients upon first medical contact 1
• Supplemental oxygen should be administered to maintain arterial saturation >90% in patients with pulmonary congestion 1
• Morphine sulfate should be given to patients with pulmonary congestion or ongoing ischemic pain 1
• Oral beta-blocker therapy should be administered promptly to patients without contraindications, regardless of reperfusion strategy 1
• Intravenous beta-blockers may be reasonable for patients without contraindications, especially with tachyarrhythmias or hypertension 1

Reperfusion Strategies

Primary PCI (Preferred Strategy)

• Primary PCI should be performed within 90 minutes of first medical contact (door-to-balloon time) 1
• For patients presenting to non-PCI capable facilities, transfer for primary PCI is recommended if the first medical contact-to-device time can be achieved within 120 minutes 1
• Antiplatelet therapy before PCI:
  • P2Y12 inhibitor (prasugrel, ticagrelor, or clopidogrel) should be administered as early as possible 1, 2
  • Prasugrel (60 mg loading dose, 10 mg daily maintenance) is indicated for STEMI patients undergoing PCI, but is contraindicated in patients with prior stroke/TIA or active bleeding 2
  • Consider 5 mg daily maintenance dose of prasugrel for patients <60 kg 2

Fibrinolytic Therapy

• Administer when primary PCI cannot be performed within 120 minutes of first medical contact 1, 3
• Most effective when given within 12 hours of symptom onset 3
• Fibrinolytic-specific agents (alteplase, reteplase, tenecteplase) are preferred over non-specific agents (streptokinase) 3
• Contraindicated in patients with prior intracranial hemorrhage, known cerebrovascular lesion, or recent head trauma 3

Pharmacoinvasive Approach

• Consider for patients initially treated with fibrinolytics when:
  • Cardiogenic shock develops 1
  • Severe heart failure/pulmonary edema develops 1
  • Hemodynamic or electrical instability occurs 1
  • Evidence of failed fibrinolysis (persistent ST elevation) 4

Management of Complications

Cardiogenic Shock

• Emergency revascularization (PCI or CABG) is recommended regardless of time delay from MI onset 1
• Intra-aortic balloon counterpulsation is useful for patients who don't stabilize quickly with pharmacological therapy 1
• Consider alternative LV assist devices for refractory shock 1
• Intra-arterial monitoring is recommended 1
• Fibrinolytic therapy should be administered if PCI/CABG is not feasible 1

Pulmonary Edema/Heart Failure

• ACE inhibitors should be initiated within 24 hours in patients with anterior STEMI, heart failure, or ejection fraction ≤0.40 1
• Start with a short-acting ACE inhibitor at low dose (e.g., captopril 1-6.25 mg) 1
• Angiotensin receptor blockers should be given to patients intolerant of ACE inhibitors 1
• Aldosterone antagonists should be given to patients with EF ≤0.40 who are already receiving an ACE inhibitor and beta-blocker and have either symptomatic heart failure or diabetes 1

Mechanical Complications

• Echocardiography should be used to evaluate for mechanical complications (ventricular septal rupture, papillary muscle rupture, free wall rupture) 1
• Emergency surgical repair should be considered for patients with VSR, papillary muscle rupture, or free wall rupture 1

Post-STEMI Care

• High-intensity statin therapy should be initiated or continued in all STEMI patients without contraindications 1
• Obtain a fasting lipid profile within 24 hours of presentation 1
• Implantable cardioverter-defibrillator therapy is indicated before discharge in patients who develop sustained ventricular tachycardia/fibrillation >48 hours after STEMI (if not due to transient/reversible causes) 1
• Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor should be continued for at least 12 months in patients receiving stents 1

Special Considerations

• For patients ≥75 years old with cardiogenic shock, emergency revascularization can be effective, especially in those with good prior functional status 1
• Beta-blockers or calcium channel blockers should not be administered acutely to patients with frank cardiac failure, pulmonary congestion, or signs of low-output state 1
• For patients requiring anticoagulation (atrial fibrillation, mechanical valves, venous thromboembolism), minimize the duration of triple therapy (vitamin K antagonist, aspirin, P2Y12 inhibitor) to limit bleeding risk 1