Do I need to hold heparin (unfractionated heparin) in a patient undergoing heart catheterization?

Management of Heparin During Heart Catheterization

Heparin should be administered during heart catheterization procedures to prevent thromboembolic complications, with dosing based on access route and patient characteristics. 1

General Recommendations for Heparin Administration

• For standard left heart catheterization, administer an initial unfractionated heparin bolus of 100 U/kg (maximum 5000 U) intravenously at the start of the procedure to maintain ACT levels >200 seconds 1
• For patients undergoing transseptal puncture, heparin should be given after the puncture is completed to avoid increasing bleeding risk 2
• For left ventricular puncture procedures, heparin should be discontinued 4-6 hours before the procedure and can be restarted without a bolus more than 4 hours after peripheral vessel sheath removal 2
• Weight-based dosing is critical, as fixed-dose protocols may result in significant over or under-anticoagulation 1

Monitoring and Additional Dosing

• Target ACT should be >200 seconds for standard procedures, but consider higher targets (250-300 seconds) for high-risk thrombotic procedures 1
• Measure ACT approximately 1 hour after the initial bolus and then every 30 minutes for longer procedures 1
• For prolonged procedures (>60 minutes), administer additional boluses (50-100 U/kg) to maintain adequate anticoagulation 1

Special Considerations

Access Route Considerations

• For transradial access (preferred due to lower bleeding risk):

  • Standard heparin dosing (100 U/kg) is appropriate 2
  • Radial access is recommended when possible given the lower bleeding risk 2

• For transfemoral access:

  • Consider using vascular closure devices to minimize bleeding risk 2
  • Higher heparin doses may be required to maintain adequate anticoagulation 2

High Thrombotic Risk Patients

• For patients with mechanical heart valves or recent stroke:
  • Uninterrupted anticoagulation or minimal interruption is recommended 2
  • For patients at very high thrombotic risk, bridging with heparin should be started when INR falls below 2.0 2

Contraindications and Precautions

• Avoid heparin in patients with:

  • History of heparin-induced thrombocytopenia (HIT) 3
  • Known hypersensitivity to heparin or pork products 3
  • Uncontrolled active bleeding 3

• For patients with HIT, bivalirudin is the preferred alternative (IV bolus of 0.75 mg/kg followed by infusion at 1.75 mg/kg/hour) 1

Common Pitfalls to Avoid

• Inadequate initial dosing leading to subtherapeutic anticoagulation and increased thrombotic risk 1
• Failure to monitor ACT during prolonged procedures, resulting in inconsistent anticoagulation 1
• Overlooking the possibility of HIT in patients with previous heparin exposure 1, 4
• Crossing over between different anticoagulants (e.g., switching between unfractionated heparin and LMWH), which increases bleeding risk 2

Post-Procedure Management

• After uncomplicated coronary intervention, there appears to be little value in continuing heparin therapy 2
• Routine use of unfractionated heparin after an uncomplicated coronary angioplasty is no longer recommended and may be associated with more frequent bleeding events 2
• For patients on oral anticoagulants, restart therapy after careful evaluation of bleeding risk and post-procedure complications 2

By following these evidence-based recommendations, you can optimize anticoagulation during heart catheterization while minimizing both thrombotic and bleeding risks.