In an adult with acute ST‑elevation myocardial infarction who has received loading doses of aspirin and a P2Y12 inhibitor, what is the next step when ST‑segment elevation persists?

ST-Elevation Persisting After Loading Doses: Immediate Management

When ST-segment elevation persists despite loading doses of aspirin and a P2Y12 inhibitor, the patient should be immediately transferred to a PCI-capable center for rescue PCI, as this represents failed fibrinolysis requiring urgent mechanical reperfusion. 1

Clinical Context and Recognition

This scenario indicates one of two situations:

• Failed fibrinolysis (if fibrinolytic therapy was given) – persistent coronary occlusion despite pharmacologic reperfusion 1
• Primary PCI delay – patient received antiplatelet loading but definitive mechanical reperfusion has not yet occurred 2

The persistence of ST-elevation beyond 60-90 minutes after fibrinolytic administration signals treatment failure and mandates immediate action. 1

Immediate Management Algorithm

Step 1: Transfer to PCI-Capable Center (Class IIa, Level B)

• All patients with failed reperfusion or reocclusion after fibrinolytic therapy should undergo urgent coronary angiography and rescue PCI. 1
• Transfer should occur immediately, without waiting for additional medical therapy to take effect. 2
• The ACC/AHA guidelines classify this as a Class IIa recommendation with Level B evidence, indicating it is reasonable and supported by moderate-quality data. 1

Step 2: Do NOT Readminister Fibrinolytic Agents

• Readministration of a fibrinolytic agent is NOT recommended as the primary strategy for persistent ST-elevation. 1
• The REACT trial demonstrated that readministration of fibrinolytics was not superior to conservative therapy and significantly inferior to rescue PCI. 1
• A second dose of a non-immunogenic fibrinolytic may only be considered if rescue PCI is absolutely unavailable, the infarct is large, and bleeding risk is low – but this is a last resort. 1

Step 3: Anticoagulation Support for PCI

• Continue or initiate unfractionated heparin with additional boluses as needed to support the PCI procedure. 1
• Weight-adjusted UFH dosing should be administered, taking into account whether GP IIb/IIIa receptor antagonists have been given. 1
• Fondaparinux should NOT be used as the sole anticoagulant for PCI due to catheter thrombosis risk (Class III: Harm). 1

Step 4: P2Y12 Inhibitor Management

For patients who already received a loading dose of clopidogrel with fibrinolytic therapy:

• Continue clopidogrel 75 mg daily without an additional loading dose. 1

For patients who have NOT received a P2Y12 loading dose:

• Give clopidogrel 300 mg if PCI will occur within 24 hours of fibrinolytic therapy. 1
• Give clopidogrel 600 mg if PCI will occur more than 24 hours after fibrinolytic therapy. 1
• Prasugrel 60 mg is reasonable once coronary anatomy is known, but should NOT be given sooner than 24 hours after a fibrin-specific agent. 1

Critical Timing Considerations

• The European Society of Cardiology emphasizes that rescue PCI should be performed as soon as possible after recognition of failed fibrinolysis, ideally within 120 minutes of STEMI diagnosis. 2
• Persistent ST-elevation represents ongoing myocardial injury and infarct expansion, making time-to-reperfusion the most critical determinant of mortality and morbidity. 2

Common Pitfalls to Avoid

Pitfall 1: Waiting for "More Time" for Medications to Work

• Once ST-elevation persists beyond 60-90 minutes after fibrinolysis, further delay worsens outcomes. 1, 2
• Do not wait for additional antiplatelet effects – proceed directly to mechanical reperfusion. 2

Pitfall 2: Giving Additional Fibrinolytic Doses

• This increases bleeding risk (especially intracranial hemorrhage in elderly patients) without improving outcomes compared to rescue PCI. 1

Pitfall 3: Treating Non-Culprit Vessels During Rescue PCI

• Only the infarct-related artery should be treated during the acute rescue PCI procedure unless the patient is in cardiogenic shock. 2

Pitfall 4: Using Prasugrel Too Early After Fibrinolysis

• Prasugrel should NOT be administered within 24 hours of fibrin-specific fibrinolytic therapy due to increased bleeding risk. 1
• Prasugrel is also contraindicated in patients with prior stroke or TIA (Class III: Harm). 1

Post-Rescue PCI Management

• Continue aspirin 81-325 mg daily indefinitely (81 mg preferred). 1
• Continue P2Y12 inhibitor (clopidogrel 75 mg, prasugrel 10 mg, or ticagrelor 90 mg twice daily) for 12 months. 1, 3
• Continuous cardiac monitoring for at least 24 hours to detect arrhythmias. 2
• Monitor for recurrent ischemia with serial ECGs and clinical assessment. 2

Alternative Scenario: No Fibrinolysis Given Yet

If the patient received only antiplatelet loading doses but no reperfusion therapy has been attempted:

• Primary PCI remains the definitive treatment and should be performed within 90-120 minutes of first medical contact. 2
• If primary PCI cannot be performed within 120 minutes, fibrinolytic therapy should be initiated immediately. 2
• The persistent ST-elevation in this context simply confirms the diagnosis and urgency – it does not represent treatment failure. 2