What is the role of tenecteplase (thrombolytic agent) in the management of myocardial infarction (MI)?

Role of Tenecteplase in Myocardial Infarction Management

Tenecteplase is a fibrin-specific thrombolytic agent recommended for reperfusion therapy in ST-elevation myocardial infarction (STEMI) when primary percutaneous coronary intervention (PCI) cannot be performed in a timely manner within 90-120 minutes of first medical contact. 1

Primary Reperfusion Strategy

• Primary PCI is the preferred reperfusion strategy for STEMI when it can be performed by an experienced team within 90-120 minutes of STEMI diagnosis 1, 2
• When primary PCI cannot be performed in a timely manner, fibrinolytic therapy should be initiated as soon as possible, preferably in the pre-hospital setting 1
• A fibrin-specific agent (tenecteplase, alteplase, or reteplase) is recommended over non-fibrin-specific agents 1

Tenecteplase Administration

• Tenecteplase is administered as a single weight-adjusted intravenous bolus 3:
  • 30 mg for weight <60 kg
  • 35 mg for 60-69 kg
  • 40 mg for 70-79 kg
  • 45 mg for 80-89 kg
  • 50 mg for ≥90 kg
• For patients ≥75 years old, a 50% dose reduction is recommended to reduce stroke risk 2

Advantages of Tenecteplase

• Tenecteplase has higher fibrin specificity and resistance to plasminogen activator inhibitor-1 compared to other thrombolytics 4
• Its longer half-life (90-130 minutes) allows for single-bolus administration, making it more convenient than infusion regimens 3, 5
• In the ASSENT-2 trial, tenecteplase showed equivalent 30-day mortality rates (6.2%) compared to alteplase but with fewer noncerebral bleeding complications 3, 4

Adjunctive Therapy with Tenecteplase

• Oral or IV aspirin (150-325 mg) should be administered immediately 1
• Clopidogrel should be added to aspirin 1, 2
• Anticoagulation should be administered until revascularization or for the duration of hospital stay (up to 8 days) 1:
  • Enoxaparin IV followed by subcutaneous (preferred over unfractionated heparin) 1
  • Unfractionated heparin as weight-adjusted IV bolus followed by infusion 1

Post-Fibrinolytic Management

• Transfer to a PCI-capable center following fibrinolysis is indicated in all patients immediately after fibrinolysis 1
• Rescue PCI is indicated immediately when fibrinolysis has failed (<50% ST-segment resolution at 60-90 minutes) or in the presence of hemodynamic or electrical instability 1
• Angiography and PCI of the infarct-related artery is recommended between 2-24 hours after successful fibrinolysis 1

Special Considerations

• Tenecteplase is particularly beneficial in patients presenting late (>4 hours after symptom onset) due to its higher fibrin specificity 1, 4
• Tenecteplase is contraindicated in patients with prior intracranial hemorrhage, known structural cerebral vascular lesion, ischemic stroke within 3 months, suspected aortic dissection, active bleeding, or significant closed-head trauma within 3 months 1
• For patients in cardiogenic shock, primary PCI remains the preferred strategy over fibrinolytic therapy 1, 2

Efficacy and Safety Profile

• Tenecteplase achieves TIMI grade 3 flow (complete reperfusion) in approximately 63-66% of patients at 90 minutes 3
• Intracranial hemorrhage risk is similar to alteplase (approximately 0.9%) 3
• Noncerebral bleeding complications are lower with tenecteplase compared to alteplase (26.4% vs. 29.0%) 3, 4

Tenecteplase represents an important reperfusion option for STEMI patients when timely primary PCI is not available, offering the convenience of single-bolus administration while maintaining efficacy comparable to other fibrinolytic agents with a favorable bleeding profile.