Is fibrinolysis (breakdown of fibrin) done in all ST-elevation myocardial infarctions (STEMI)?

Fibrinolysis in ST-Elevation Myocardial Infarction (STEMI)

Fibrinolysis is not performed in all ST-elevation myocardial infarctions (STEMI), but rather is reserved for specific clinical scenarios when primary percutaneous coronary intervention (PCI) cannot be performed in a timely manner. 1

Primary Reperfusion Strategy for STEMI

Primary PCI vs. Fibrinolysis

• Primary PCI is the preferred reperfusion strategy for STEMI when it can be performed within 90 minutes of first medical contact 2
• Fibrinolysis should be administered when primary PCI cannot be performed within 120 minutes of first medical contact 3
• The mortality benefit of fibrinolysis is directly related to time from symptom onset, with maximum benefit achieved with earliest possible administration 1

Indications for Fibrinolysis in STEMI

Fibrinolytic therapy should be administered to STEMI patients when:

• Symptom onset is within 12 hours 1
• ST elevation >0.1 mV in at least 2 contiguous precordial leads or 2 adjacent limb leads 1
• New or presumably new left bundle branch block (LBBB) 1
• Primary PCI cannot be performed within the recommended timeframe 1

Contraindications to Fibrinolysis

Absolute contraindications include:

• History of intracranial hemorrhage
• Significant closed head or facial trauma within past 3 months
• Uncontrolled hypertension
• Ischemic stroke within past 3 months
• Active bleeding or bleeding diathesis
• Suspected aortic dissection 1, 2

Decision Algorithm for Reperfusion in STEMI

1. First Medical Contact (FMC) Assessment:

   • Obtain 12-lead ECG within 10 minutes
   • Establish IV access
   • Administer aspirin 160-325 mg 2

2. Reperfusion Decision:

   • If primary PCI available within 90-120 minutes → Choose primary PCI
   • If primary PCI not available within 120 minutes → Administer fibrinolysis within 30 minutes of FMC 3
   • If patient has contraindications to fibrinolysis → Transfer for primary PCI regardless of time delay 1

3. Post-Fibrinolysis Management:

   • Monitor for reperfusion success
   • Consider rescue PCI for failed fibrinolysis (60-120 minutes after administration) 1
   • For successful fibrinolysis, consider early angiography within 24 hours 1

Current Practice Challenges

Despite guidelines recommending door-to-needle times ≤30 minutes for fibrinolysis, only 44.5% of patients receive fibrinolysis within this timeframe 4. Delays in fibrinolysis are associated with worse outcomes, including higher rates of death, shock, and stroke 4.

Special Considerations

• Patients ≥75 years have higher risk of intracranial hemorrhage with fibrinolysis 1
• Patients with high risk of intracranial hemorrhage (≥4%) should receive primary PCI rather than fibrinolysis 1
• In areas where primary PCI facilities are unavailable, modern fibrinolytic strategies (immediate fibrinolysis followed by transfer for rescue or early PCI) remain essential 5

Common Pitfalls to Avoid

1. Delaying fibrinolysis when primary PCI cannot be performed within the recommended timeframe
2. Administering fibrinolysis when contraindicated (especially in patients with history of intracranial bleeding)
3. Failing to recognize failed fibrinolysis and delaying rescue PCI
4. Not transferring patients to PCI-capable centers after fibrinolysis for potential early angiography
5. Using fibrinolysis in patients with only ST-segment depression (unless posterior MI is suspected) 1

The decision between primary PCI and fibrinolysis should be based on time from symptom onset, anticipated delays to primary PCI, contraindications to fibrinolysis, and available healthcare resources. While primary PCI is preferred when available in a timely manner, fibrinolysis remains a critical reperfusion strategy for many STEMI patients worldwide.