Heparin Regimen After TNK for STEMI

Standard UFH Dosing Protocol

The American College of Cardiology recommends unfractionated heparin (UFH) as a 60 U/kg IV bolus (maximum 4,000 U) followed by 12 U/kg/hour infusion (maximum 1,000 U/hour), adjusted to maintain aPTT at 1.5-2.0 times control (50-70 seconds), and continued for at least 48 hours up to 8 days or until revascularization 1, 2
The initial bolus of UFH should be 60 U/kg IV (maximum 4,000 U) 1, 2
The maintenance infusion of UFH should be 12 U/kg/hour (maximum 1,000 U/hour for patients >70 kg) 1, 2
The target aPTT for UFH therapy should be 1.5-2.0 times control (approximately 50-70 seconds) 1, 2

The American College of Cardiology recommends checking aPTT at 3, 6, 12, and 24 hours after initiation of UFH therapy, and rechecking 4-6 hours after any dose adjustment 1, 2, 3
Daily platelet count monitoring is recommended to detect heparin-induced thrombocytopenia 1, 2, 3

The minimum duration of UFH therapy should be 48 hours 3
The preferred duration of UFH therapy is throughout index hospitalization, up to 8 days 3, 4

The American College of Cardiology recommends enoxaparin as an acceptable alternative to UFH in select patients, with a dosing regimen of 30 mg IV bolus followed by 1.0 mg/kg subcutaneous every 12 hours 1, 2
Enoxaparin is contraindicated in patients aged ≥75 years, or with significant renal dysfunction 1, 2, 4

If glycoprotein IIb/IIIa inhibitors are planned, the UFH bolus should be reduced to 50-70 U/kg (instead of 60 U/kg) 5, 6
The target ACT during PCI should be 200-250 seconds (vs 250-300 seconds without GP IIb/IIIa) 6, 3

For patients with heparin-induced thrombocytopenia, bivalirudin represents an alternative, with a dosing regimen of 0.25 mg/kg bolus followed by 0.5 mg/kg/hour for 12 hours, then 0.25 mg/kg/hour for 36 hours 2, 4
The European Society of Cardiology guidelines emphasize that UFH remains the standard therapy for STEMI patients undergoing primary PCI, and switching between UFH and LMWH should be avoided 7