Management of ST-Elevation Myocardial Infarction (STEMI)

Initial Assessment and Immediate Actions

The American College of Cardiology recommends obtaining a 12-lead ECG within 10 minutes of emergency department arrival for all patients with chest discomfort or STEMI symptoms 1, 2.
STEMI is confirmed by ST-segment elevation >0.1 mV in at least two contiguous precordial or adjacent limb leads, new left bundle branch block, or true posterior MI 1.
If the initial ECG is non-diagnostic but clinical suspicion remains high, perform serial ECGs at 5-10 minute intervals or use continuous 12-lead ST-segment monitoring 1, 2.
Administer aspirin 162-325 mg immediately upon first medical contact—this is non-negotiable for all STEMI patients 1, 2, 3.
Place the patient on continuous cardiac monitoring for arrhythmia detection 3.

Primary PCI is the preferred reperfusion strategy if first medical contact-to-device time can be achieved within 120 minutes 1, 2, 3.
If primary PCI cannot be performed within 120 minutes, immediately initiate fibrinolytic therapy within 30 minutes of hospital arrival using a fibrin-specific agent 1, 2, 3.
Tenecteplase is preferred as a single weight-adjusted IV bolus; reduce the dose by 50% in patients ≥75 years old to reduce stroke risk 3.
Transfer all patients receiving fibrinolysis to a PCI-capable center immediately after administration for angiography between 2-24 hours post-fibrinolysis 3, 4.

For primary PCI, administer dual antiplatelet therapy with aspirin plus a potent P2Y12 inhibitor before the procedure 1, 3.
Prasugrel 60 mg loading dose is preferred over clopidogrel for patients undergoing primary PCI, provided they have no history of stroke/TIA and are not ≥75 years old 3.
For fibrinolysis, use aspirin plus clopidogrel as the P2Y12 inhibitor of choice 1.
Anticoagulation: Use unfractionated heparin as weight-adjusted IV bolus followed by infusion for primary PCI 3.
Continue dual antiplatelet therapy for at least 12 months in patients receiving stents 2.

Beta-blockers should be administered promptly unless contraindications exist (frank heart failure, hypotension, persistent tachycardia, bradycardia, or signs of low-output state) 2, 3, 5, 6.
Morphine sulfate 2-4 mg IV with increments of 2-8 mg at 5-15 minute intervals for ongoing ischemic pain or pulmonary congestion 2, 3.
Oxygen supplementation only if arterial oxygen saturation <90%—routine oxygen administration is not beneficial 2, 3.
Avoid ibuprofen as it blocks the antiplatelet effects of aspirin 5, 6.

Initiate ACE inhibitors within 24 hours in all patients, particularly those with anterior MI, heart failure, or ejection fraction ≤0.40 2, 3, 5, 6.
High-intensity statin therapy should be started in all STEMI patients without contraindications 2.
Warfarin (INR 2.0-3.0) is indicated for patients with persistent or paroxysmal atrial fibrillation 5, 7.

Emergency revascularization (PCI or CABG) is recommended regardless of time delay from MI onset for patients with cardiogenic shock 1, 2, 3, 4.
Intra-aortic balloon counterpulsation is useful for patients with cardiogenic shock not quickly stabilized with pharmacological therapy 1, 2, 3.

Cardiac rehabilitation programs are recommended for all STEMI patients, particularly those with multiple modifiable risk factors 7.
Smoking cessation is mandatory—provide counseling to patient and family, along with pharmacological therapy (nicotine replacement and bupropion) and formal smoking-cessation programs 5, 6.
Routine echocardiography during hospital stay to assess LV and RV function, detect mechanical complications, and exclude LV thrombus 1.