What is the role of vitamin K (Vit K) injection in correcting elevated International Normalized Ratio (INR) in patients with heart failure (HF) and reduced ejection fraction (EF)?

Vitamin K Injection for Elevated INR in Heart Failure with Reduced Ejection Fraction

For patients with heart failure and reduced ejection fraction who have elevated INR, vitamin K injection should not be routinely used for INR correction unless the INR exceeds 10 or active bleeding is present. 1

Management Algorithm Based on INR Level

For INR 4.5-10 Without Bleeding:

• First-line approach: Withhold vitamin K antagonist (VKA) therapy temporarily
• Not recommended: Routine administration of vitamin K 1
• Rationale: Evidence shows no significant difference in major bleeding outcomes between vitamin K administration and simply withholding VKA (2% vs 0.8%)

For INR >10 Without Bleeding:

• Consider: Low-dose oral vitamin K (2.5 mg)
• Rationale: May reduce INR more rapidly than withholding VKA alone
• Evidence: Retrospective data shows patients given oral vitamin K 2 mg were less likely to still have INR >5 by day 3 compared to those who only had warfarin withheld (11.1% vs 46.7%) 1

For Any INR with Active Bleeding:

• Recommended: Rapid reversal with vitamin K 10 mg IV plus prothrombin complex concentrate (PCC) 1
• Alternative: Fresh frozen plasma if PCC unavailable
• Important: IV vitamin K should be infused slowly due to risk of anaphylaxis (3 in 100,000 patients) 1

Special Considerations in Heart Failure Patients

Heart failure patients with reduced ejection fraction require careful management of anticoagulation due to:

1. Higher risk of thromboembolism, especially with atrial fibrillation
2. Potential hemodynamic compromise from bleeding events
3. Medication interactions affecting INR stability

Route of Administration When Vitamin K Is Needed

• Preferred route: Oral administration for non-emergency situations 2
• IV administration: Reserved for emergency situations requiring rapid reversal 1
• Not recommended: Subcutaneous injection (less effective than IV, with risk of cutaneous reactions) 2

Dosing Considerations

• For INR 4.5-10: If vitamin K is deemed necessary despite recommendations, use 1-2.5 mg oral dose 2
• For INR >10: 2.5-5 mg oral dose may be appropriate 2
• For active bleeding: 10 mg IV plus coagulation factor replacement 1

Pitfalls and Caveats

1. Overcorrection risk: Using high doses of vitamin K can lead to resistance to re-anticoagulation
2. Thromboembolism risk: Rapid reversal may increase risk of thrombotic events, particularly concerning in HF patients
3. Anaphylaxis risk: IV vitamin K carries risk of anaphylactoid reactions 2
4. Rebound effect: Without vitamin K, simply giving coagulation factors may lead to rebound anticoagulation as factors are consumed 3

Monitoring After Intervention

• Check INR within 24 hours after any intervention
• For patients requiring temporary discontinuation of anticoagulation, assess thromboembolism risk
• Consider resuming anticoagulation once INR returns to therapeutic range, especially in high-risk patients

The decision to use vitamin K for INR correction should balance the risks of bleeding against the risks of thromboembolism, with particular attention to the unique cardiovascular needs of heart failure patients with reduced ejection fraction.