Uninterrupted warfarin with a single vitamin K dose for surgery
Vitamin K Reversal of INR for Perioperative Management of Warfarin: : A Pilot Study to Assess Feasibility
This study tries giving one dose of vitamin K before surgery to people on long-term warfarin to see if they can safely keep taking warfarin through the procedure.
Quick facts
| Phase | Phase 4 |
|---|---|
| Study type | Interventional |
| Enrollment | 20 (estimated) |
| Ages | 18 Years and up |
| Sex | All |
| Sponsor | University of Michigan Academic / other |
| Locations | 1 site (Ann Arbor, Michigan) |
| Trial ID | NCT07515664 on ClinicalTrials.gov |
What this trial studies
This feasibility study tests continuing warfarin without interruption and giving a single preoperative oral vitamin K dose to lower INR to a safe level before surgery. Participants must have been on warfarin for at least three months, use home INR testing, and be scheduled for a procedure that typically requires an INR ≤ 1.5. Investigators will measure INR responses after the single pre-procedure vitamin K dose and will also compare whether an immediate postoperative vitamin K loading dose helps the INR return to therapeutic range faster than standard warfarin resumption. The study is being conducted at Michigan Medicine and uses home INR monitoring to track perioperative INR changes.
Who should consider this trial
Good fit: Ideal candidates are adults on stable warfarin therapy for at least three months who use home INR testing, have an INR ≤ 4 at screening (day 7–10 before procedure), and are scheduled for a procedure requiring an INR ≤ 1.5.
Not a fit: Patients undergoing high-bleeding-risk procedures, those with recent thrombotic events, very high stroke risk (CHA2DS2-VASc > 6), LVADs, lack of English proficiency, or INR > 4 at screening are excluded and unlikely to benefit from this approach.
Why it matters
Potential benefit: If successful, this approach could allow patients to avoid stopping warfarin around surgery and return to therapeutic INR sooner, potentially lowering clot risk from missed doses.
How similar studies have performed: There is limited prior data on uninterrupted warfarin with a single pre-op vitamin K dose, so this specific strategy remains largely untested in controlled trials.
Eligibility criteria
Show full inclusion / exclusion criteria
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)
Where this trial is running
Ann Arbor, Michigan
- Michigan Medicine — Ann Arbor, Michigan, United States (Recruiting)
Study contacts
- Principal investigator: Geoffrey Barnes, MD — University of Michigan
- Study coordinator: Geoffrey Barnes, MD
- Email: gbarnes@med.umich.edu
- Phone: 734 936-4000
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.