Anticoagulation Therapy in NSTEMI

Introduction to Anticoagulation

The American College of Cardiology recommends enoxaparin as a preferable alternative to unfractionated heparin (UFH) in patients with NSTEMI, unless severe renal impairment or CABG is planned within 24 hours, with a Level of Evidence A 1

For patients with NSTEMI managed with an initial conservative approach, the American Heart Association suggests enoxaparin (Class IIa, Level of Evidence A) or fondaparinux (Class IIa, Level of Evidence B) as reasonable alternatives to UFH 2, 3
Enoxaparin demonstrates similar or improved composite outcomes compared to UFH, though with a small increase in minor bleeding complications, in patients with NSTEMI 2, 3
For patients with NSTEMI proceeding to early catheterization and possible PCI, the American College of Cardiology recommends either enoxaparin or UFH as reasonable choices (Class IIa, Level of Evidence A) 2, 3

The American College of Cardiology recommends administering enoxaparin 1 mg/kg subcutaneously every 12 hours for 2-8 days or until hospital discharge 1
Antiplatelet therapy with aspirin and/or clopidogrel must be added to anticoagulation (Class I, Level of Evidence A), according to the American Heart Association 1

If PCI occurs within 8 hours of the last subcutaneous enoxaparin dose, no additional anticoagulation is needed, as recommended by the American College of Cardiology 4
If PCI is planned 8-12 hours after the last dose, an additional intravenous dose of 0.3 mg/kg enoxaparin should be administered immediately before PCI, according to the American Heart Association 4

For patients with severe renal impairment (CrCl <30 mL/min), the American College of Cardiology recommends UFH as the first-line anticoagulant, as it does not require renal dose adjustment and allows precise titration via aPTT monitoring 5
If enoxaparin must be used in patients with severe renal impairment, the dose should be reduced to 1 mg/kg subcutaneously once daily with mandatory anti-Xa monitoring, as suggested by the American Heart Association 5
Bivalirudin or UFH may be considered (Class IIb, Level of Evidence A) in patients with renal insufficiency, according to the American College of Cardiology 2, 3

Switching between enoxaparin and UFH in either direction significantly increases bleeding risk (Class III recommendation - causes harm), as warned by the American Heart Association 2, 3, 4
The American College of Cardiology recommends not using ACT as a guide to anticoagulation in patients receiving enoxaparin, as low-molecular-weight heparins have little effect on ACT measurements 4
Standard twice-daily enoxaparin dosing (1 mg/kg q12h) should never be used in patients with CrCl <30 mL/min without dose reduction and anti-Xa monitoring, as recommended by the American College of Cardiology 5