Vitamin K for Perioperative Warfarin Management

Purpose

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

Condition

  • Patients Anti-coagulated With Warfarin Who Require Surgery

Eligibility

Eligible Ages
Over 18 Years
Eligible Sex
All
Accepts Healthy Volunteers
No

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)

Study Design

Phase
Phase 4
Study Type
Interventional
Allocation
Randomized
Intervention Model
Parallel Assignment
Primary Purpose
Treatment
Masking
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
Standard Warfarin Dosing with Vitamin K 		Patients will receive their standard warfarin dosing before, during, and after their procedure. This is in addition to a one time dose of oral vitamin K pre-procedure.
  • Drug: Vitamin K
    10 mg of oral vitamin K will be given approximately 36-48 hours before procedure.
  • Drug: Warfarin (standard without loading)
    Patients receive their standard warfarin dosing without interruption.
    Other names:
    • Coumadin
Experimental
Loading Warfarin Dosing with Vitamin K 		Patients will receive their standard warfarin dosing before and during their procedure. On the night following the procedure, they will receive a one time loading dose of warfarin (twice their normal dose). Patients will then resume normal dosing of warfarin. This is in addition to a one time dose of oral vitamin K pre-procedure.
  • Drug: Vitamin K
    10 mg of oral vitamin K will be given approximately 36-48 hours before procedure.
  • Drug: Warfarin (standard with loading)
    Patients receive their standard warfarin dosing without interruption; patients also receive a one time loading dose (twice normal dose) of warfarin on the evening following their procedure.
    Other names:
    • Coumadin

Recruiting Locations

Michigan Medicine
Ann Arbor, Michigan 48109
Contact:
Geoffrey Barnes, MD
734 936-4000
gbarnes@med.umich.edu

More Details

Status
Recruiting
Sponsor
University of Michigan

Study Contact

Geoffrey Barnes, MD
734 936-4000
gbarnes@med.umich.edu

Detailed Description

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.