Vitamin K versus Warfarin Interruption Alone in Patients without Bleeding and an International Normalized Ratio >10

BACKGROUND: Reversal of an international normalized ratio (INR) >10 with vitamin K is recommended in patients experiencing bleeding; however, information on outcomes with reversal using vitamin K in non-bleeding patients is lacking. OBJECTIVE: To compare clinical and safety outcomes between non-bleeding patients receiving warfarin with an INR >10 who did and did not receive a prescription for vitamin K. PATIENTS/METHODS: This was a retrospective cohort study conducted in an integrated healthcare delivery system. Adult patients receiving warfarin therapy who experienced an INR >10 without bleeding between 01/01/2006 and 06/30/2018 were included. Patients were assessed for an outpatient dispensing or in-office administration of vitamin K on the day of or the day after an INR >10 and then clinically-relevant bleeding, thromboembolism, all-cause mortality, and time to INR 0.05). Patients dispensed vitamin K had a higher likelihood of mortality (15.1% vs. 10.1%, p=0.032, adjusted odds ratio=1.63, 95% confidence interval 1.03 to 2.57). Overall, time to an INR 10.