Unfractionated Heparin Dosing for NSTEMI

Initial Dosing Recommendations

The American College of Cardiology recommends an initial bolus of 60 U/kg (maximum 4,000 U) followed by an infusion of 12 U/kg/hour (maximum 1,000 U/hour) for patients with Non-ST-Elevation Myocardial Infarction (NSTEMI), with dose adjustments to maintain activated partial thromboplastin time (aPTT) at 1.5 to 2.0 times control (approximately 50 to 70 seconds) 1, 2
The maintenance dose should be an IV infusion of 12 U/kg/hour (maximum 1,000 U/hour) for NSTEMI patients, as recommended by the American College of Cardiology 1, 2
The target aPTT should be 1.5 to 2.0 times control (approximately 50 to 70 seconds) for NSTEMI patients, according to the American College of Cardiology 2
The available data do not suggest a benefit of prolonging the duration of the UFH infusion beyond 48 hours in the absence of ongoing indications for anticoagulation in NSTEMI patients, as stated in Circulation 3

For NSTEMI patients who will undergo percutaneous coronary intervention (PCI) with glycoprotein (GP) IIb/IIIa inhibitors, the American College of Cardiology recommends targeting an activated clotting time (ACT) of 200 seconds 1, 2
For NSTEMI patients who will undergo PCI without GP IIb/IIIa inhibitors, the American College of Cardiology recommends targeting an ACT of 250-300 seconds for HemoTec device or 300-350 seconds for Hemochron device 1, 2

Frequent monitoring of aPTT is essential to ensure therapeutic anticoagulation while minimizing bleeding risk in NSTEMI patients, as recommended by the American College of Cardiology 2
Excess dosing (>70 U/kg for bolus or >15 U/kg/hour for infusion) is associated with increased risk of major bleeding in NSTEMI patients, according to Circulation 3

For patients with renal insufficiency, standard UFH is preferred over low molecular weight heparin as it does not require dose adjustment for renal function, as stated in Praxis Medical Insights 4
Patients who have already received one form of anticoagulant (e.g., enoxaparin) should not be given additional UFH to avoid increased bleeding risk, according to Circulation and Praxis Medical Insights 5, 6

The American College of Cardiology recommends enoxaparin as an alternative anticoagulation option for NSTEMI, with a dose of 1 mg/kg subcutaneously every 12 hours (maximum 10,000 IU twice daily) 1
Bivalirudin is an alternative anticoagulation option for NSTEMI, with a dose of 0.1 mg/kg bolus, followed by 0.25 mg/kg/hour infusion, as recommended by the American College of Cardiology 1
Fondaparinux is an alternative anticoagulation option for NSTEMI, with a dose of 2.5 mg subcutaneously once daily, as recommended by the American College of Cardiology 1

Switching between different anticoagulants during the same admission increases bleeding risk in NSTEMI patients, according to Circulation and Praxis Medical Insights 5, 6
Failure to adjust dosing based on renal function can lead to accumulation and increased bleeding risk in NSTEMI patients, as stated in Praxis Medical Insights 4