How to reverse an International Normalized Ratio (INR) of 5 in a patient with a Left Ventricular Assist Device (LVAD)?

Reversing an INR of 5 in a Patient with an LVAD

For a patient with an LVAD and an INR of 5 without active bleeding, the recommended approach is to hold warfarin doses temporarily and consider administering low-dose oral vitamin K (1-2 mg) to gradually reduce the INR to therapeutic range. 1, 2

Assessment of Bleeding Risk

First, determine if the patient has active bleeding:

• No active bleeding:

  • Hold warfarin doses
  • Consider oral vitamin K 1-2 mg
  • Monitor INR within 24 hours
  • Resume warfarin at a lower dose when INR approaches target range

• With active bleeding:

  • For minor bleeding: Hold warfarin and consider oral vitamin K 1-2 mg
  • For major/life-threatening bleeding: Administer intravenous prothrombin complex concentrate (PCC) along with low-dose vitamin K (1-2 mg) 1

Specific Management Algorithm

For INR of 5 without bleeding:

1. Hold 1-2 doses of warfarin
2. Consider oral vitamin K 1-2 mg (preferred over IV route due to lower risk of anaphylaxis) 1
3. Check INR within 24 hours
4. Resume warfarin at a reduced dose (typically 10-20% lower than previous) when INR approaches therapeutic range

For INR of 5 with bleeding:

1. Minor bleeding: Hold warfarin, administer oral vitamin K 1-2 mg, monitor closely
2. Major bleeding: Administer PCC (dosing based on INR level) plus low-dose vitamin K 1
   • For INR 4-6: 35 units/kg (maximum 3500 units) of PCC 2
   • PCC is preferred over fresh frozen plasma due to faster reversal and lower volume 1

Special Considerations for LVAD Patients

LVAD patients require careful management due to competing risks:

• Thrombotic risk: LVADs have a high risk of device thrombosis if anticoagulation is inadequate
• Bleeding risk: Excessive anticoagulation increases bleeding complications

The target INR for most LVAD patients is typically 2.0-3.0, similar to mechanical aortic valves 2, 3. Pharmacist-managed INR self-testing has been shown to improve time in therapeutic range for LVAD patients (44.4% vs 30.6% with usual care) 3.

Timing of Anticoagulation Resumption

After INR normalization:

• Resume warfarin therapy as soon as bleeding risk allows
• For patients at high thrombotic risk (including LVAD patients), consider resuming within 72 hours once hemostasis is achieved 2
• Consider a 10-20% dose reduction from previous maintenance dose

Pitfalls and Caveats

1. Avoid high-dose vitamin K: Using doses >5 mg may lead to prolonged warfarin resistance and difficulty re-establishing therapeutic anticoagulation, increasing thrombosis risk 1, 2

2. Monitor for LVAD thrombosis: Even with supratherapeutic INR, LVAD thrombosis can still occur. Maintain high suspicion for device thrombosis regardless of INR level 4

3. Avoid complete reversal unless necessary: In patients with small intracranial hemorrhages, some studies suggest that carefully selected LVAD patients may be safely managed by discontinuing anticoagulation and allowing INR to normalize physiologically rather than aggressive reversal 5

4. Consider frequent INR monitoring: After reversal, more frequent INR monitoring (every 1-2 days) is recommended until stable therapeutic range is achieved 2, 6

5. Investigate cause of elevated INR: Always identify and address the underlying cause of the elevated INR (medication interactions, dietary changes, etc.) to prevent recurrence 1