From the Guidelines
Heparin can be administered to a patient with STEMI in cardiac arrest as part of the standard treatment protocol. The recommended dose is typically an initial bolus of unfractionated heparin at 60-70 units/kg (maximum 4,000-5,000 units) followed by an infusion of 12-15 units/kg/hour (maximum 1,000 units/hour), adjusted to maintain an activated partial thromboplastin time (aPTT) of 1.5-2.5 times control, as suggested by the anticoagulation strategies for primary percutaneous coronary intervention 1. For patients undergoing primary percutaneous coronary intervention (PCI), a higher bolus dose of 70-100 units/kg may be used.
Heparin administration should continue during resuscitation efforts as it prevents further clot formation and extension of the coronary thrombosis that caused the STEMI. The anticoagulant effect of heparin helps maintain vessel patency, especially if thrombolytic therapy is administered or if the patient undergoes emergency PCI, as recommended in the 2015 American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care 1.
However, clinicians should be aware of the increased bleeding risk, particularly with prolonged CPR, and should monitor for signs of bleeding. In patients with known heparin-induced thrombocytopenia, alternative anticoagulants such as bivalirudin or argatroban should be considered instead. Key considerations in the management of STEMI patients in cardiac arrest include:
- The importance of prompt reperfusion therapy, either through fibrinolysis or primary PCI, as emphasized in the guidelines 1
- The need for careful monitoring of anticoagulation and bleeding risks, particularly in patients receiving heparin 1
- The potential benefits of emergency coronary angiography in patients with suspected cardiac etiology of arrest and ST elevation on ECG, as recommended in the guidelines 1
From the Research
Administration of Heparin in STEMI with Cardiac Arrest
- The use of heparin in patients with ST-Elevation Myocardial Infarction (STEMI) is a common practice, especially during primary percutaneous coronary intervention (PPCI) 2, 3.
- However, the administration of heparin in STEMI patients who are in cardiac arrest is a more complex issue.
- A study published in 2024 found that pre-hospital heparin administration was not associated with improved infarct vessel patency or mortality in STEMI patients with out-of-hospital cardiac arrest 4.
- The study suggested that the use of heparin in this setting may not have a significant impact on patient outcomes.
Comparison with Other Anticoagulants
- Bivalirudin is an alternative anticoagulant that has been compared to heparin in STEMI patients undergoing PPCI 2, 5.
- A meta-analysis published in 2024 found that bivalirudin reduced all-cause mortality, cardiac mortality, and major bleeding compared to heparin, but increased reinfarction and stent thrombosis 5.
- However, the study also found that bivalirudin with a high-dose post-PCI infusion reduced cardiac mortality and major bleeding without an increase in ischemic events compared to heparin monotherapy.
Heparin Dosing and Administration
- The dosing and administration of heparin in STEMI patients is crucial to ensure effective anticoagulation and minimize the risk of bleeding 6.
- The American College of Cardiology/American Heart Association guidelines recommend an initial heparin bolus of 60 U/kg (maximum, 4000 U) followed by a 12-U/kg/h infusion (maximum 1000 U/h) for STEMI patients undergoing PPCI 6.
- However, the optimal dosing and administration of heparin in STEMI patients with cardiac arrest is not well established and requires further study.