Management of Acute Myocardial Infarction

Initial Diagnosis and Assessment

• The European Society of Cardiology recommends obtaining a 12-lead ECG within 10 minutes of first medical contact and initiating continuous ECG monitoring with defibrillator capacity immediately 1, 2, 3
• Record and interpret the ECG at the point of first medical contact, whether pre-hospital or in-hospital, with a maximum target delay of 10 minutes 1, 2, 3
• Look for ST-segment elevation in two contiguous leads, but also recognize STEMI equivalents including new bundle branch block, ventricular pacing, hyperacute T-waves, isolated ST-depression in anterior leads, or universal ST depression with ST-elevation in aVR 2
• Administer oxygen only if oxygen saturation is below 90%—routine oxygen administration is not recommended 1, 3

Reperfusion Strategy Selection

• The European Society of Cardiology recommends choosing primary PCI if it can be performed within 120 minutes of STEMI diagnosis; otherwise, initiate fibrinolysis immediately (within 10 minutes) 2, 4
• Administer loading dose of aspirin (oral or IV if unable to swallow) immediately 1, 2, 3
• Give loading dose of prasugrel or ticagrelor (not clopidogrel) for primary PCI 1, 2, 3
• Administer unfractionated heparin as first-line anticoagulant (enoxaparin or bivalirudin are alternatives) 1, 2, 3

Primary PCI Pathway

• Use radial access as the standard approach 1, 2, 3
• Implant drug-eluting stents routinely 1, 2, 3
• Do not perform routine thrombus aspiration or deferred stenting—these are contraindicated 1, 2, 3

Fibrinolysis Pathway

• Initiate fibrinolytic therapy within 10 minutes of STEMI diagnosis if the patient presents within 12 hours of symptom onset and has no contraindications 4
• Use a fibrin-specific agent: tenecteplase, alteplase, or reteplase 4
• Administer aspirin loading dose (oral or IV) 4, 5
• Give clopidogrel loading dose immediately—this is the only P2Y12 inhibitor indicated with fibrinolysis (do not use prasugrel or ticagrelor initially) 4, 5

Post-Reperfusion Care

• Monitor patients for at least 24 hours after reperfusion therapy 1, 2, 3
• Pursue early ambulation and early discharge in uncomplicated patients 1, 2, 3
• Perform routine echocardiography during hospital stay to assess left and right ventricular function, detect mechanical complications, and exclude left ventricular thrombus 4

Maintenance Antithrombotic Therapy

• Continue dual antiplatelet therapy with aspirin plus prasugrel or ticagrelor for 12 months after PCI 1, 2, 3, 4, 5
• For patients initially treated with fibrinolysis and clopidogrel, switch to prasugrel or ticagrelor at the time of angiography/PCI 4, 5

Special Considerations for Cardiac Arrest

• Perform primary PCI in patients with resuscitated cardiac arrest and ST-elevation on post-resuscitation ECG 1, 2, 3
• In cases without ST-elevation but high suspicion of ongoing ischemia, perform urgent angiography within 2 hours after excluding non-coronary causes 1, 2, 3
• Initiate targeted temperature management early after resuscitation in patients who remain unresponsive 1, 3

Critical Pitfalls to Avoid

• Do not use prasugrel or ticagrelor as the initial P2Y12 inhibitor with fibrinolytic therapy—clopidogrel is specifically indicated in this setting, with transition to potent agents at the time of PCI 4, 5
• Do not delay transfer to a PCI-capable center after fibrinolysis—all patients require angiography regardless of apparent lysis success 4, 5
• Do not miss the 2-24 hour window for routine angiography after successful fibrinolysis—this timing is evidence-based and improves outcomes 4, 5
• Do not perform routine thrombus aspiration or deferred stenting during primary PCI—these strategies are contraindicated 1, 2, 3

Guideline Recommendations for STEMI Diagnosis, Reperfusion, and Post‑Reperfusion Management

Initial Diagnosis and Stabilization

• Obtain a 12‑lead electrocardiogram within 10 minutes of first medical contact and start continuous cardiac monitoring with defibrillator capability; if primary PCI can be performed within 120 minutes, it is the preferred reperfusion strategy, otherwise fibrinolytic therapy should be given within 10 minutes together with aspirin, clopidogrel and anticoagulation – European Society of Cardiology (ESC) STEMI guideline 6
• Record and interpret the 12‑lead ECG at the point of first medical contact with a maximum delay of 10 minutes – ESC STEMI guideline 6, 7, 8
• Begin ECG monitoring with defibrillator capacity immediately upon patient contact – ESC STEMI guideline 6, 7, 8
• Administer supplemental oxygen only when peripheral oxygen saturation is < 90 %; routine oxygen in patients with adequate saturation is not recommended – ESC STEMI guideline 6, 7

Reperfusion Strategy

Primary PCI (preferred when door‑to‑balloon ≤ 120 min)

• Give an aspirin loading dose (oral or intravenous if the patient cannot swallow) before PCI – ESC STEMI guideline 6, 8
• Give a loading dose of a potent P2Y12 inhibitor (prasugrel or ticagrelor) – clopidogrel is not recommended for primary PCI – ESC STEMI guideline 6, 7
• Use unfractionated heparin as the first‑line anticoagulant; low‑molecular‑weight heparin (enoxaparin) or bivalirudin are acceptable alternatives – ESC STEMI guideline 6
• Transfer the patient directly to the catheterisation laboratory, bypassing the emergency department – ESC STEMI guideline 6, 8

Fibrinolysis (when primary PCI cannot be achieved within 120 minutes)

• Fibrinolytic therapy is indicated for patients presenting within 12 hours of symptom onset who have no contraindications – ESC STEMI guideline 6, 7
• Use a fibrin‑specific thrombolytic agent (tenecteplase, alteplase, or reteplase) – ESC STEMI guideline 6
• Give an aspirin loading dose (oral or intravenous) together with fibrinolysis – ESC STEMI guideline 8
• Administer a loading dose of clopidogrel (the only P2Y12 inhibitor recommended with fibrinolysis; prasugrel and ticagrelor should not be used initially) – ESC STEMI guideline 7

Special Populations

• In patients who achieve return of spontaneous circulation after cardiac arrest and show ST‑elevation on the post‑resuscitation ECG, primary PCI should be performed – ESC STEMI guideline 6, 7
• Early targeted temperature management is recommended for resuscitated patients who remain unresponsive – ESC STEMI guideline 6, 7
• Pre‑hospital cooling with large volumes of cold intravenous fluid is contraindicated – ESC STEMI guideline 6, 7
• Routine PCI of an occluded infarct‑related artery performed > 48 hours after symptom onset is not indicated in asymptomatic patients – ESC STEMI guideline 6, 7
• In patients on chronic oral anticoagulants, with renal insufficiency, or who are elderly, dose adjustments of antithrombotic and anticoagulant therapies should be carefully considered – ESC STEMI guideline 6, 7

Post‑Reperfusion Care

• Monitor all patients for at least 24 hours after reperfusion therapy – ESC STEMI guideline 6, 7, 8
• Promote early ambulation and consider early discharge in patients with an uncomplicated clinical course – ESC STEMI guideline 6, 7
• Continue dual antiplatelet therapy with aspirin plus prasugrel or ticagrelor for 12 months after PCI, unless contraindicated (e.g., high bleeding risk) – ESC STEMI guideline 7, 8