Can I use thrombolysis with tissue plasminogen activator (tPA) in a patient with ST-elevation myocardial infarction (STEMI)?

Management of STEMI: Primary PCI vs. Thrombolysis with tPA

Primary PCI is the preferred reperfusion strategy for STEMI patients when it can be performed within 120 minutes of first medical contact, but thrombolysis with tPA is an appropriate alternative when timely PCI is not available.

Reperfusion Strategy Decision Algorithm

Primary PCI (Preferred Option)

• Primary PCI has demonstrated superior outcomes compared to fibrinolytic therapy in multiple studies 1, 2
• Benefits include:
  • Lower short-term mortality rates
  • Less nonfatal reinfarction
  • Reduced risk of hemorrhagic stroke
  • Better reperfusion rates

When to Use Thrombolysis with tPA

• When primary PCI cannot be performed within 120 minutes of first medical contact 2
• Particularly beneficial when administered within the first 3 hours of symptom onset 1
• Should be initiated as soon as possible after STEMI diagnosis, preferably pre-hospital 2

Time-Based Decision Points

1. Within 0-3 hours of symptom onset: Both options viable; PCI preferred to prevent stroke 1
2. Within 3-12 hours of symptom onset: PCI strongly preferred to salvage myocardium 1
3. Beyond 12 hours: Primary PCI only recommended if clinical/ECG evidence of ongoing ischemia 2

Thrombolysis with tPA (Alteplase) Protocol

If choosing thrombolysis:

• Dosing: Weight-based, not to exceed 100 mg total dose 3
• Administration: IV infusion with specific protocol per FDA labeling 3
• Anticoagulation: Enoxaparin IV followed by SC is preferred over unfractionated heparin 2

Important Considerations

Contraindications to Thrombolysis

• Active internal bleeding
• Recent intracranial/intraspinal surgery or serious head trauma
• History of recent stroke
• Bleeding diathesis
• Current severe uncontrolled hypertension 3

High-Risk Patients

• For cardiogenic shock: Primary PCI is strongly recommended regardless of time delay 2
• PCI shows greatest mortality benefit in high-risk patients 1
• In the SHOCK trial, an absolute 9% reduction in 30-day mortality was observed with coronary revascularization 1

Post-Thrombolysis Management

• Even after successful thrombolysis, coronary angiography within 24 hours and PCI, if applicable, should be considered (pharmacoinvasive approach) 1, 4

Clinical Pitfalls to Avoid

1. Delaying reperfusion decision: Time is myocardium - make prompt decisions about reperfusion strategy
2. Underutilization of reperfusion therapy: A significant proportion of STEMI patients don't receive any reperfusion therapy, leading to worse outcomes 1
3. Inadequate PCI infrastructure: Primary PCI should only be performed in hospitals with established interventional programs and experienced teams 1
4. Ignoring transfer times: When calculating the 120-minute window for primary PCI, include realistic transfer times to PCI-capable centers
5. Overlooking bleeding risk: Thrombolysis carries higher risk of major bleeding and stroke compared to PCI 5

Quality Metrics for Primary PCI Programs

For centers performing primary PCI, the following benchmarks should be met:

• Medical contact-to-balloon or door-to-balloon times less than 90 minutes
• TIMI 2/3 flow rates obtained in more than 90% of patients
• Emergency CABG rate less than 2% among all patients undergoing the procedure
• Actual performance of PCI in a high percentage of patients (85%) brought to the laboratory
• Risk-adjusted in-hospital mortality rate less than 7% in patients without cardiogenic shock 1

Remember that the ultimate goal is rapid and complete reperfusion to reduce infarct size, preserve left ventricular function, and improve survival. The choice between primary PCI and thrombolysis should be guided by local resources, time factors, and patient-specific contraindications.