Can anticoagulation be held in a patient with a Left Ventricular Assist Device (LVAD)?

Anticoagulation Management in LVAD Patients

Anticoagulation should not be held in patients with Left Ventricular Assist Devices (LVADs) due to the significantly increased risk of ischemic stroke and death associated with discontinuation of anticoagulation for ≥30 days. 1

Rationale for Continuous Anticoagulation in LVAD Patients

LVAD patients have a high risk of thromboembolic complications that can occur at any point after implantation. These complications represent a major therapeutic challenge in this population and can lead to devastating outcomes including:

• Pump thrombosis
• Ischemic stroke
• Systemic thromboembolism
• Death

Evidence Supporting Continuous Anticoagulation

Research demonstrates that discontinuing anticoagulation for ≥30 days in LVAD patients is independently associated with:

• 8.5-fold increased risk of ischemic stroke
• 3.9-fold increased risk of death 1

The American Heart Association/American Stroke Association guidelines clearly state that warfarin together with aspirin is the standard antithrombotic regimen to minimize the risk of LVAD pump thrombosis and to prevent recurrent ischemic stroke or TIA. 2

Anticoagulation Protocol for LVAD Patients

1. Standard anticoagulation regimen:

   • Warfarin (target INR 2.5-3.5) 3
   • Aspirin 75-100 mg daily 2, 3

2. Monitoring requirements:

   • Regular INR monitoring to maintain therapeutic range
   • Aim for >60% time in therapeutic range (PTTR >60%), which is associated with significantly lower risk of both thromboembolism (HR: 0.37) and hemorrhage (HR: 0.45) 4

3. Contraindications to DOACs:

   • Direct oral anticoagulants (DOACs) should be avoided in LVAD patients 2, 3
   • Use of dabigatran instead of warfarin in LVAD patients causes harm (Class 3: Harm; Level of Evidence: B-R) 2

Management of Bleeding in LVAD Patients

If a patient with an LVAD develops bleeding:

1. Temporary interruption approach:

   • For minor bleeding: Consider temporary reduction of INR target while maintaining some anticoagulation effect
   • For major bleeding: Reverse anticoagulation with appropriate agents while planning for prompt reinitiation

2. Reversal of anticoagulation:

   • For warfarin: Administer 4-factor prothrombin complex concentrate (PCC) and vitamin K 2
   • Reversal of anticoagulation in LVAD patients does not appear to be associated with LVAD-related thrombosis based on observational data 2

3. Reinitiation strategy:

   • Restart anticoagulation as soon as hemostasis is achieved
   • For high rebleeding risk but high thrombotic risk, consider unfractionated heparin infusion initially due to its short half-life and availability of reversal agent 2
   • Avoid bridging with enoxaparin as it is associated with a fourfold increase in major bleeding events 5

Important Considerations and Pitfalls

• Avoid prolonged interruption: Even short periods off anticoagulation increase thrombotic risk
• Avoid supratherapeutic INR: Patients with bleeding events tend to have higher median INR (2.7) compared to those with thrombotic events (2.2) 6
• Coordinate with LVAD team: Always coordinate with the LVAD care team when considering any changes to anticoagulation 2
• Beware of drug interactions: Many medications can affect warfarin metabolism and INR stability
• Monitor for signs of pump thrombosis: Changes in pump parameters, hemolysis markers, or new heart failure symptoms

Conclusion

The evidence strongly supports maintaining continuous anticoagulation in LVAD patients. The risks of thromboembolism and death from withholding anticoagulation outweigh the risks of bleeding in most scenarios. When bleeding occurs, temporary reversal with a plan for prompt reinitiation is the safest approach.