Vitamin K for Perioperative Warfarin Management

Vitamin K Reversal of INR for Perioperative Management of Warfarin: : A Pilot Study to Assess Feasibility

This is a feasibility study of uninterrupted warfarin with a one time dose of Vitamin K before a surgical procedure.

Historically, warfarin is held for 5 days before a surgical procedure to obtain a safe INR (international normalized ratio) that minimizes bleeding risk. However, there is a strong rationale for continuing warfarin uninterrupted in the perioperative space and giving a one-time vitamin K dose to get a safe INR pre-operatively. This feasibility study will recruit patients who use warfarin and will measure their INR response after receiving a single pre-procedure vitamin K dose. This study will also assess the use of a one-time "loading" dose immediately post-operative to help the INR return to the therapeutic range sooner than continuing with the standard warfarin dosing.

Inclusion Criteria:

• Warfarin therapy for ≥3 months
• Use of home INR testing equipment
• Scheduled for a surgical procedure that requires INR ≤ 1.5 (typically achieved with warfarin interruption)
• INR ≤ 4 on day 7-10 prior to procedure

Exclusion Criteria:

• Surgical procedure does not require INR ≤1.5 (typically achieved with warfarin interruption)
• Surgical procedure with a high risk of bleeding or complications (urologic procedures, bronchoscopy, epidural injections, nerve blocks, spinal surgery)
• Warfarin therapy for < 3 months
• Lack of English language proficiency
• Use of a Heartmate II or HVAD left ventricular assist device
• Recent thrombotic event (within 3 months)
• CHA2DS2-VASc score >6
• INR >4 on day 7-10 prior to procedure
• Hypersensitivity to any component of Vitamin K or simple syrup (used in the compounding process)