Acute Myocardial Infarction Management with Tenecteplase

Introduction to Tenecteplase Administration

• The American College of Cardiology recommends a single intravenous weight-based bolus of Tenecteplase (TNK) administered over 5 seconds, with dosing as follows: 30 mg for weight <60 kg, 35 mg for 60-69 kg, 40 mg for 70-79 kg, 45 mg for 80-89 kg, and 50 mg for ≥90 kg, according to the weight-based dosing regimen [1]
• The following table outlines the TNKase dosing and administration volumes:

Timing and Patient Selection for Tenecteplase Administration

• Initiate treatment as soon as possible after onset of STEMI symptoms, with the greatest benefit occurring within the first 12 hours after symptom onset [1]
• Tenecteplase may be considered in symptomatic patients presenting >12 hours after symptom onset with a large area of myocardium at risk or hemodynamic instability when PCI is unavailable [1]

Adjunctive Therapies with Tenecteplase

• The American College of Cardiology recommends antiplatelet therapy with aspirin (162-325 mg loading dose, followed by daily maintenance) and clopidogrel (300 mg loading dose for patients <75 years of age, 75 mg for patients ≥75 years) [1, 2]
• Anticoagulation with unfractionated heparin (UFH) or enoxaparin is recommended, with UFH administered as a 60 U/kg IV bolus (maximum 4000 U) followed by 12 U/kg/hr infusion (maximum 1000 U/hr), adjusted to maintain aPTT at 1.5-2.0 times control [3]

Special Considerations for Tenecteplase Administration

• Consider half-dose for patients >75 years old to reduce the risk of intracranial hemorrhage [2]
• Post-fibrinolysis care should include transfer to a PCI-capable center immediately after fibrinolytic therapy and early angiography between 2 and 24 hours with intent to perform PCI to reduce rates of death or MI [1]

Contraindications and Precautions for Tenecteplase Administration

• Absolute contraindications include any prior intracranial hemorrhage, known structural cerebral vascular lesion, known malignant intracranial neoplasm, ischemic stroke within 3 months, suspected aortic dissection, active bleeding or bleeding diathesis, significant closed-head or facial trauma within 3 months, intracranial or intraspinal surgery within 2 months, and severe uncontrolled hypertension (SBP >180 mm Hg or DBP >110 mm Hg) [1]
• Relative contraindications include history of chronic, severe, poorly controlled hypertension, significant hypertension on presentation, history of prior ischemic stroke >3 months, dementia, known intracranial pathology not covered in absolute contraindications, traumatic or prolonged CPR, major surgery (<3 weeks), recent internal bleeding, noncompressible vascular punctures, pregnancy, and active peptic ulcer [1]

Benefits of Tenecteplase

• Tenecteplase has higher fibrin specificity compared to other thrombolytic agents and offers several advantages, including single bolus administration, equivalent 30-day mortality rates compared to alteplase, and reduced non-cerebral bleeding compared to alteplase [1]