Anticoagulant Therapy
Conditions
Brief summary
This is a feasibility study of uninterrupted warfarin with a one time dose of Vitamin K before a surgical procedure.
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.
Interventions
DRUGVitamin K
10 mg of oral vitamin K will be given approximately 36-48 hours before procedure.
DRUGWarfarin (standard without loading)
Patients receive their standard warfarin dosing without interruption.
DRUGWarfarin (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.
Sponsors
University of Michigan
National Heart, Lung, and Blood Institute (NHLBI)
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
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)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Feasibility of patient recruitment | Within two weeks (from outreach to five days prior to procedure) | Percentage of recruited patients among those initially screened |
| INR reversal | Within 12 hours prior to procedure | Percentage of enrolled patients with an INR less than or equal to 1.5 on morning of procedure |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Fidelity to intervention protocol | 12 day span from 2 days pre-operative through 10 days post-operative | Percent of patients who achieved both elements of the intervention: 1) continued warfarin uninterrupted peri-operatively; 2) Administration of oral vitamin K on the evening of pre-operative day 2 |
| Fidelity to randomization | 24 hours (day of procedure) | Percent of patients who used the appropriate dose of warfarin that was recommended immediately post -procedure based on randomization |
| Cost per recruited patient | 12 day span from 2 days pre-operative through 10 days post-operative | Study costs per patient recruited through end of follow up. Inclusive of personnel, supplied, medication costs. |
| Patient acceptability | 10 days post procedure | Data gathered with an acceptability survey, measured on a Likert scale ranging from 1-5 where 5 means most acceptable and 1 means least acceptable. |
| Clinical acceptability | 10 days post procedure | Data gathered with an acceptability survey, on a Likert scale ranging from 1-5 where 5 means most acceptable and 1 means least acceptable. |
| Therapeutic INR by post-operative day 5 | day 5 post procedure | Percent of patients whose INR has returned to their therapeutic range by day 5 post-procedure |
| Adverse events | 30 days post procedure | Any bleeding or thromboembolic complication that occurs with 30-days following the surgical procedure |
| Canceled procedures | 24 hours prior to procedure | Percent of procedures that are canceled due to an INR greater than 1.5 |
| Additional warfarin reversal pre-operative | 24 hours pre-procedure | Use of any additional warfarin reversal agents (e.g., fresh frozen plasma, prothrombin complex concentrate, additional vitamin K) |
Countries
United States
Contacts
CONTACTGeoffrey Barnes, MD
PRINCIPAL_INVESTIGATORGeoffrey Barnes, MD
University of Michigan
Outcome results
None listed