The effect of administering preprocedural VITamin K on the international normalized ratio in patients anticoagulated with ACEnocoumarol (VITKACE-study): a prospective cohort study

Abstract

Background: The effect of the vitamin K antagonist acenocoumarol on coagulation needs to be reversed when patients undergo an invasive procedure with considerable bleeding risk. A strategy to achieve this is by administering oral vitamin K before a procedure while continuing acenocoumarol.

Objectives: To assess the effect on periprocedural international normalized ratio (INR) values and safety using oral vitamin K as anticoagulant reversal method.

Methods: In this prospective cohort study, consecutive patients using acenocoumarol undergoing elective procedures between 2019 and 2022 were included. According to standard of care in our hospital, patients took 10 mg oral vitamin K 36 to 48 hours before the procedure while continuing their normal use of acenocoumarol. Effectiveness to lower INR to <1.8 preprocedural was assessed. Bleeding and thrombotic complications within 30 days after the procedure were assessed. Periprocedural course of INR was monitored by collecting additional blood samples.

Results: Seventy-four patients were included for analysis. On the day of the procedure, an adequate INR of <1.8 was achieved in 99% of patients. One clinically relevant nonmajor bleeding complication and no thrombotic complications were observed during the first 30 days after the procedure. INR gradually restored to therapeutic level during the days after the procedure.

Conclusion: Using oral vitamin K while patients continue acenocoumarol intake is an effective way to adequately lower INR before an invasive procedure. Low amount of bleeding complications and absence of thromboembolic complications suggest that this is a safe strategy. The INR values returned gradually to therapeutic range after the procedure, probably contributing to the observed low bleeding rate.

Keywords: acenocoumarol; hemorrhage; international normalized ratio; thromboembolism; vitamin K.