Timing of Subcutaneous Heparin After Impella Removal
Subcutaneous heparin should be initiated 4-6 hours after Impella removal in patients requiring anticoagulation, provided there are no signs of bleeding at the access site. 1
Risk Assessment for Post-Impella Anticoagulation
The decision to initiate subcutaneous heparin after Impella removal should be based on the patient's thromboembolism risk:
High Thromboembolism Risk Patients
- Recent (<3 months) stroke or TIA
- Mechanical heart valves (especially mitral position or older-generation valves)
- Recent (<3 months) venous thromboembolism
- Severe thrombophilia
- CHA₂DS₂-VASc score ≥7 or CHADS₂ score of 5-6 2
Moderate Thromboembolism Risk Patients
- Mitral valve without major risk factors
- CHA₂DS₂-VASc score of 5-6 or CHADS₂ score of 3-4
- VTE within past 3-12 months 2
Low Thromboembolism Risk Patients
- Bileaflet AVR without major risk factors
- CHA₂DS₂-VASc score of 1-4 or CHADS₂ score of 0-2
- VTE >12 months ago 2
Protocol for Subcutaneous Heparin Initiation After Impella
Initial Assessment (0-4 hours post-removal):
- Monitor access site for bleeding
- Check hemoglobin/hematocrit and coagulation parameters
Timing of Initiation:
- High-risk patients: Start subcutaneous heparin 4-6 hours after Impella removal if no bleeding 1
- Moderate-risk patients: Start subcutaneous heparin 6-12 hours after Impella removal
- Low-risk patients: Consider delaying heparin for 12-24 hours or using prophylactic dosing only
Dosing Considerations:
- For therapeutic anticoagulation: Weight-based dosing (e.g., 100 IU/kg twice daily)
- For prophylactic anticoagulation: Fixed dose (e.g., 5000 IU every 8-12 hours) 2
Special Considerations
Bleeding Risk Management
- Lower heparin targets appear to reduce major bleeding events without increasing thrombotic complications in post-Impella patients 3
- Careful monitoring of access site is crucial during the first 24 hours after device removal
- Consider prophylactic rather than therapeutic dosing in patients with high bleeding risk
Monitoring Parameters
- Check for access site bleeding before each dose
- Monitor platelet count for heparin-induced thrombocytopenia
- For patients transitioning to oral anticoagulation, continue subcutaneous heparin until INR is therapeutic for 48 hours 2
Pitfalls to Avoid
- Avoid immediate post-removal anticoagulation in patients with visible bleeding at access site
- Avoid crossing over between different anticoagulants (e.g., switching between LMWH and UFH) as this increases bleeding risk 2
- Avoid high-intensity anticoagulation immediately after Impella removal, as higher ACT levels (>168s) during Impella support have been associated with increased 30-day mortality 4
The timing of subcutaneous heparin after Impella removal requires balancing thrombotic and bleeding risks. While the American College of Neurosurgery recommends initiating heparin 4-6 hours after catheter removal in patients requiring anticoagulation 1, this timing should be adjusted based on individual patient risk factors and the presence of bleeding at the access site.