What is the appropriate thrombolytic treatment for a patient with acute myocardial infarction (AMI) when primary percutaneous coronary intervention (PCI) cannot be performed promptly?

Thrombolytic Treatment for Acute Anterior Wall Myocardial Infarction

For patients with acute anterior wall myocardial infarction (AWMI) who cannot receive timely primary PCI, tenecteplase (TNKase) is the recommended fibrinolytic agent due to its fibrin specificity, ease of administration as a single bolus, and established efficacy in reducing mortality. 1, 2

Reperfusion Strategy Decision Algorithm

1. Primary assessment:

   • Confirm STEMI diagnosis with 12-lead ECG within 10 minutes of arrival 1, 3
   • Determine time since symptom onset 1
   • Assess for contraindications to fibrinolysis 2

2. Choose reperfusion strategy:

   • If primary PCI can be performed within 90-120 minutes of first medical contact → Choose primary PCI 1
   • If primary PCI cannot be performed within 120 minutes → Administer fibrinolytic therapy within 30 minutes of arrival 1

Fibrinolytic Therapy Administration

• Timing: Administer as soon as possible, ideally within 12 hours of symptom onset 1
• Agent of choice: Fibrin-specific agent (tenecteplase, alteplase, or reteplase) 1
• Dosing for tenecteplase: Weight-based single IV bolus over 5 seconds 2
• Adjunctive therapy:
  • Aspirin 150-325 mg (oral or IV if unable to swallow) 1
  • Clopidogrel loading dose followed by daily maintenance 1
  • Anticoagulation with enoxaparin (preferred) or unfractionated heparin 1

Post-Fibrinolysis Management

• Transfer: All patients should be transferred to a PCI-capable center immediately after fibrinolysis 1
• Monitoring: Continuous cardiac monitoring for arrhythmias and bleeding complications 3, 2
• Rescue PCI indications:
  • Failed fibrinolysis (<50% ST-segment resolution at 60-90 minutes) 1
  • Hemodynamic or electrical instability 1
  • Recurrent ischemia 1
• Timing of angiography if fibrinolysis successful: 2-24 hours after fibrinolysis 1

Special Considerations for Anterior MI

• Higher risk for left ventricular dysfunction and heart failure 3
• Increased risk for mural thrombus formation and embolic stroke 3
• Greater likelihood of conduction disturbances and arrhythmias 3
• Perform echocardiography to evaluate LV function and detect complications 3

Potential Complications and Management

• Bleeding: Most common adverse reaction; avoid intramuscular injections and monitor closely 2
• Arrhythmias: Have anti-arrhythmic therapy available during administration 2
• Hypersensitivity reactions: Monitor during and for several hours after infusion 2
• Thromboembolism: Increased risk in patients with left heart thrombus 2

Common Pitfalls to Avoid

• Delaying fibrinolysis: Every minute counts; administer within 30 minutes of arrival if primary PCI is not available within 120 minutes 1
• Inadequate anticoagulation: Continue anticoagulation until revascularization or for up to 8 days 1
• Missing the transfer window: All patients should be transferred to a PCI-capable center after fibrinolysis 1
• Overlooking contraindications: Carefully screen for active bleeding, prior stroke, recent surgery/trauma, and uncontrolled hypertension 2
• Failing to recognize failed fibrinolysis: Monitor for <50% ST-segment resolution at 60-90 minutes and arrange immediate rescue PCI if needed 1