Heparin Administration in STEMI Patients
Primary PCI Strategy
- The American College of Cardiology recommends unfractionated heparin (UFH) administration as a weight-adjusted intravenous bolus of 70-100 U/kg (maximum 5,000 U) when used alone in patients undergoing primary percutaneous coronary intervention (PCI) 1
- A reduced dose of 60 U/kg (maximum 4,000 U) should be used when UFH is administered with glycoprotein IIb/IIIa inhibitors in patients undergoing primary PCI 1
- Target activated clotting time (ACT) should be 250-350 seconds (200-250 seconds with GPIIb/IIIa inhibitors) in patients undergoing primary PCI 1
- Heparin infusion is typically discontinued at the end of the primary PCI procedure in patients undergoing primary PCI 1
Fibrinolytic Therapy Strategy
- The American Heart Association recommends UFH administration as a 60 U/kg IV bolus (maximum 4,000 U) followed by an infusion of 12 U/kg/hour (maximum 1,000 U/hour) in patients receiving fibrinolytic therapy 2, 3
- The infusion should be adjusted to maintain activated partial thromboplastin time (aPTT) at 1.5 to 2.0 times control (approximately 50 to 70 seconds) in patients receiving fibrinolytic therapy 3, 4
- Anticoagulation should continue for a minimum of 48 hours, and preferably for the duration of the index hospitalization, up to 8 days or until revascularization if performed in patients receiving fibrinolytic therapy 3
- For patients receiving fibrin-specific agents, heparin is strongly recommended 3
- For patients receiving non-selective fibrinolytic agents, heparin is particularly important for those at high risk for systemic emboli 5
No Reperfusion Therapy
- The European Society of Cardiology recommends UFH administration as soon as possible in patients not receiving reperfusion therapy 6
- Weight-adjusted dosing of 60-70 U/kg IV bolus followed by 12-15 U/kg/hour infusion is recommended in patients not receiving reperfusion therapy 4
- Angiography before hospital discharge is recommended, similar to patients after successful fibrinolysis, in patients not receiving reperfusion therapy 6
Monitoring and Safety Considerations
- For patients on fibrinolytic therapy, aPTT should be checked at 3, 6, 12, and 24 hours after initiation 1, 4
- Daily monitoring of platelet counts is recommended in patients receiving UFH 5
- More frequent monitoring of aPTT and full weight adjustment of heparin may decrease the risk of non-cerebral bleeding complications 1
- The American College of Cardiology recommends considering enoxaparin (low-molecular-weight heparin) as an alternative to UFH in patients under 75 years of age receiving fibrinolytic therapy, provided significant renal dysfunction is not present 5
Alternative Anticoagulants
- The American College of Cardiology recommends considering enoxaparin (low-molecular-weight heparin) as an alternative to UFH in patients under 75 years of age receiving fibrinolytic therapy, provided significant renal dysfunction is not present 5
- For patients ≥75 years receiving enoxaparin, the initial bolus should be omitted and starting with 0.75 mg/kg SC every 12 hours is recommended 4