Vitamin K (Phytonadione) Administration in 6 Left Ventricular Assist Device (LVAD) Patients to Stabilize INR

Background/Aims: Careful INR management to mitigate risk of LVAD hemolysis/thrombosis is complicated by dietary variability in vitamin K consumption. Patients may struggle with supratherapeutic and subtherapeutic INR values despite stable warfarin dosing which poses risks for both bleeding and thrombosis. We describe a patient for whom daily vitamin K administration was successfully utilized to stabilize INR. Methods: We identified 6 patients who had erratic INR readings despite stable doses of warfarin for whom low dose Vitamin K was initiated; 3 patients were supported with HeartWare LVADs, 2 with HeartMate III, and 1 with HeartMate II. Patients were evenly divided with regard to gender and indication as the cohort consisted of 3 males and 3 female, and 3 bridge to transplant (BTT) candidates and 3 destination therapy (DT) candidates. Results: Patients were supported with LVAD on average 153 days prior to Vitamin K administration (range 20 days to 371 days), spent on average 6.7 days in the hospital related to INR concerns, and had an average of 0.8 admissions prior to Vitamin K administration. Post Vitamin K administration, average hospitalizations per patient decreases to 0.7, number of days spent in the hospital related to INR admission fell to 2.8 days. Patients were followed on average for 114 days (range 1 day to 398 days) post vitamin K administration and did not experience any mortality or adverse events related to Vitamin K administration. Conclusion: Clotting factors II, VII, IX, and X and Protein C and S require vitamin K which is inhibited by Warfarin. Inconsistent vitamin K intake will increase and decrease clotting ability. Providing daily baseline vitamin k dosing reduces influence of daily variability of dietary vitamin K consumption and with frequent INR monitoring was safely done in this patient population. Baseline vitamin K dosing may reduce thrombus risk in LVAD patients with labile INRs and allows for improved outpatient INR management.