NCT07515664 · University of Michigan
Vitamin K for Perioperative Warfarin Management
What this study is about
This is a feasibility study of uninterrupted warfarin with a one time dose of Vitamin K before a surgical procedure.
View original scientific description
This is a feasibility study of uninterrupted warfarin with a one time dose of Vitamin K before a surgical procedure.
Interventions
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.
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.
Primary outcome measures
Feasibility of patient recruitment
Time frame: Within two weeks (from outreach to five days prior to procedure)
Percentage of recruited patients among those initially screened
INR reversal
Time frame: Within 12 hours prior to procedure
Percentage of enrolled patients with an INR less than or equal to 1.5 on morning of procedure
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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
- Ann Arbor, Michigan
Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Apr 13, 2026 · Source of record for eligibility and locations