Immediate Management of Code STEMI
Activate the cardiac catheterization laboratory immediately and transfer the patient directly to the cath lab, bypassing the emergency department if possible, while simultaneously administering aspirin 162-325 mg (chewed) and obtaining a 12-lead ECG within 10 minutes of first medical contact. 1, 2
Initial Assessment and Diagnosis (0-10 minutes)
- Obtain 12-lead ECG within 10 minutes of first medical contact—diagnosis requires >0.1 mV ST-segment elevation in two contiguous leads, new left bundle branch block, or true posterior MI pattern 1, 2
- Do not delay reperfusion therapy for additional testing except when alternate diagnoses like aortic dissection or pericarditis are suspected 1
- Establish IV access and draw labs (troponin, CBC, INR, aPTT, electrolytes, creatinine, lipid panel) but do not wait for results before proceeding 1
- Apply continuous cardiac monitoring with defibrillator immediately available 3
Immediate Medical Therapy (Administer Simultaneously)
Antiplatelet Therapy
- Aspirin 162-325 mg oral (chewed) or 250-500 mg IV if unable to swallow—administer immediately as first-line therapy 1, 3, 2
- P2Y12 inhibitor loading dose before or at time of PCI 1, 2:
Symptom Management
- Morphine sulfate 2-4 mg IV, repeat 2-8 mg every 5-15 minutes as needed for chest pain 1
- Nitroglycerin 0.4 mg sublingual every 5 minutes (maximum 3 doses) UNLESS 1:
- Systolic BP <90 mmHg or >30 mmHg below baseline
- Heart rate <50 or >100 bpm
- Right ventricular infarction suspected
- Phosphodiesterase inhibitor use within 24 hours (48 hours for tadalafil)
- Oxygen supplementation only if arterial saturation <90% or pulmonary congestion present 1
Reperfusion Strategy Decision (Critical Time-Dependent Choice)
PRIMARY PCI (Preferred Strategy)
Choose primary PCI if ALL of the following can be met 1, 2:
- Skilled PCI facility accessible (operators >75 cases/year, team >36 cases/year)
- First medical contact to device time ≤90 minutes (if presenting directly to PCI-capable hospital)
- First medical contact to device time ≤120 minutes (if requiring transfer)
- Door-in-door-out time ≤30 minutes for transfers 2
Primary PCI is MANDATORY regardless of time delay in 2:
- Cardiogenic shock (Killip class III or greater)
- Acute severe heart failure
- Contraindications to fibrinolysis
Primary PCI Protocol
- Anticoagulation 2:
- Unfractionated heparin 70-100 U/kg IV bolus (if no GP IIb/IIIa inhibitor planned) OR
- Bivalirudin 0.75 mg/kg IV bolus followed by 1.75 mg/kg/h infusion
- Continue enoxaparin through PCI if already administered: no additional dose if within 8 hours; 0.3 mg/kg IV bolus if 8-12 hours since last dose 2
- Drug-eluting stents or bare-metal stents are both acceptable 1
- Thrombus aspiration should be considered as important device adjunct 5
FIBRINOLYTIC THERAPY (When Primary PCI Cannot Be Achieved)
Administer fibrinolytic therapy immediately if 1, 6, 2:
- Symptom onset <12 hours
- Anticipated first medical contact to device time >120 minutes
- No contraindications to fibrinolysis
Absolute Contraindications to Fibrinolysis 1, 6
- Any prior intracranial hemorrhage
- Known structural cerebral vascular lesion or malignant intracranial neoplasm
- Ischemic stroke within 3 months
- Suspected aortic dissection
- Active bleeding or bleeding diathesis
- Significant closed-head or facial trauma within 3 months
Fibrinolytic Protocol
Adjunctive anticoagulation (minimum 48 hours, up to 8 days) 2, 1:
- Enoxaparin (preferred) 2:
- Age <75 years: 30 mg IV bolus, then 1 mg/kg subcutaneous every 12 hours (max 100 mg first 2 doses)
- Age ≥75 years: no bolus, 0.75 mg/kg subcutaneous every 12 hours (max 75 mg first 2 doses)
- CrCl <30 mL/min: 1 mg/kg subcutaneous every 24 hours
- Unfractionated heparin (alternative): 60 U/kg IV bolus (max 4000 U), then 12 U/kg/h infusion (max 1000 U), adjusted to aPTT 1.5-2.0 times control 2, 1
- Enoxaparin (preferred) 2:
Clopidogrel loading dose 1:
- Age ≤75 years: 300 mg
- Age >75 years: 75 mg (no loading dose)
Post-Fibrinolytic Management (Critical)
- Transfer ALL patients to PCI-capable center immediately after fibrinolysis 1, 6, 2
- Assess reperfusion at 60-90 minutes by ST-segment resolution, symptom relief, hemodynamic stability 1, 6
- Rescue PCI immediately if 1, 6, 2:
- <50% ST-segment resolution at 60-90 minutes (failed reperfusion)
- Hemodynamic instability develops
- Electrical instability (ventricular arrhythmias)
- Cardiogenic shock
- Routine angiography 2-24 hours after successful fibrinolysis (do NOT perform within first 2-3 hours) 2, 1, 6
Special Situations
Cardiogenic Shock
- Emergency revascularization with PCI or CABG immediately, irrespective of time delay from MI onset 2
- Intra-aortic balloon pump for patients not quickly stabilized with pharmacological therapy 2, 5
- Fibrinolytic therapy if unsuitable for PCI/CABG and no contraindications 2
Out-of-Hospital Cardiac Arrest
- Immediate angiography and PCI in resuscitated patients whose initial ECG shows STEMI 2
- Therapeutic hypothermia should be started as soon as possible in comatose patients 2
Critical Pitfalls to Avoid
- Never delay primary PCI to obtain additional imaging or consultations unless alternate life-threatening diagnosis suspected 1, 3
- Never withhold aspirin due to bleeding concerns—the mortality benefit far outweighs bleeding risk 1, 3
- Never administer beta-blockers or calcium channel blockers acutely in patients with pulmonary congestion or low-output state 2, 1
- Never perform PCI of non-infarct artery at time of primary PCI in hemodynamically stable patients 2
- Never delay fibrinolysis beyond 30 minutes of arrival when primary PCI cannot be achieved within 120 minutes 2, 1
- Avoid prasugrel in patients >75 years, <60 kg, or prior stroke/TIA due to increased bleeding risk 4
Post-Procedure Immediate Management
- High-intensity statin therapy initiated immediately 2, 1
- Beta-blockers started orally in patients with heart failure or LVEF <40% unless contraindicated 1
- ACE inhibitors within 24 hours in patients with heart failure, LV dysfunction, diabetes, or anterior infarct 1
- Dual antiplatelet therapy: aspirin 75-100 mg daily plus P2Y12 inhibitor for minimum 12 months (drug-eluting stents) or 30 days (bare-metal stents) 1, 3