When to Use Alteplase for STEMI
Alteplase is indicated for STEMI when primary PCI cannot be performed within 120 minutes of first medical contact, provided the patient presents within 12 hours of symptom onset and has no contraindications to fibrinolytic therapy. 1
Primary Indication: PCI-Related Delay
The fundamental decision point is timing to primary PCI:
- If primary PCI can be achieved within 90-120 minutes of first medical contact, proceed directly to the catheterization laboratory—fibrinolysis is NOT indicated 1, 2
- If primary PCI will be delayed beyond 120 minutes, initiate fibrinolytic therapy immediately, preferably in the pre-hospital setting 1, 3
This time-dependent approach reflects the critical reality that every minute of delay increases myocardial necrosis and worsens outcomes, with the greatest mortality benefit occurring within the first 3 hours of symptom onset 2
Specific Requirements for Alteplase Use
Patient Eligibility Criteria
- Symptom duration ≤12 hours with persistent ST-segment elevation 1
- No contraindications to fibrinolytic therapy 1
- Age considerations: Full dose for patients <75 years; half dose for patients ≥75 years 3
Alteplase as Preferred Fibrin-Specific Agent
When fibrinolysis is chosen, a fibrin-specific agent (tenecteplase, alteplase, or reteplase) is recommended over non-specific agents like streptokinase 1. The ESC guidelines give this a Class I, Level B recommendation, meaning alteplase is among the top-tier fibrinolytic choices 1
Mandatory Adjunctive Therapy with Alteplase
When administering alteplase for STEMI, you must provide:
- Aspirin (oral or IV if unable to swallow) immediately 1
- Clopidogrel (not prasugrel or ticagrelor initially) in addition to aspirin 1, 4
- Anticoagulation until revascularization or up to 8 days of hospitalization:
Post-Fibrinolysis Management Algorithm
All patients receiving alteplase require immediate transfer to a PCI-capable center regardless of apparent success 1, 4. The subsequent pathway depends on fibrinolysis outcome:
Successful Fibrinolysis
- Routine angiography and PCI between 2-24 hours after alteplase administration (Class I, Level A) 1, 4
- At time of PCI, transition from clopidogrel to a potent P2Y12 inhibitor (prasugrel or ticagrelor) 4
Failed Fibrinolysis
- Rescue PCI immediately if <50% ST-segment resolution at 60-90 minutes 1, 4
- Emergency angiography and PCI for hemodynamic instability, electrical instability, worsening ischemia, heart failure, or shock 1, 4
- Emergency PCI for recurrent ischemia or evidence of reocclusion 1, 4
Evidence Supporting Pharmaco-Invasive Strategy
Recent data demonstrate that a pharmaco-invasive approach with half-dose alteplase followed by timely PCI can achieve superior complete epicardial and myocardial reperfusion compared to delayed primary PCI (34.2% vs 22.8%, P=0.022) in patients presenting ≤6 hours with expected PCI delay 5. This strategy showed similar infarct size, left ventricular ejection fraction, and 30-day mortality, though minor bleeding was more frequent 5
Critical Contraindications and Pitfalls
Absolute Contraindications to Highlight
- Do NOT use nitrates in patients on phosphodiesterase-5 inhibitors (contraindicated for ≥48 hours after last tadalafil dose)—use morphine for pain control instead 2
- Avoid alteplase in patients with increased intracranial hemorrhage risk, as this remains the most serious complication 3, 6
Common Errors to Avoid
- Do NOT use prasugrel or ticagrelor as initial P2Y12 inhibitor with fibrinolysis—clopidogrel is specifically indicated in this setting 4
- Do NOT delay transfer to PCI-capable center after fibrinolysis, even if ST segments appear to resolve 4
- Do NOT continue clopidogrel after PCI is performed—escalate to prasugrel or ticagrelor at time of intervention 4
- Do NOT give alteplase >12 hours after symptom onset—it is ineffective and potentially harmful 6