Vitamin K for Perioperative Warfarin Management

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)