#3662 FREQUENCY OF INR TESTING IN HEMODIALYSIS PATIENTS ON VITAMIN K ANTAGONISTS: A RETROSPECTIVE STUDY

Abstract

Abstract Background and Aims Despite the rising of direct oral anticoagulant agents’ use in the general population, vitamin K antagonists (VKA) are still used in hemodialysis (HD) French patients with atrial fibrillation. These HD patients on VKA have also poor levels of time in therapeutic range. It is recommended generally to follow patients with monthly INR, however there is lack of such evidence in HD. This study aims to analyze the frequency of INR testing needed in HD patients. Method This is a retrospective study of all patients treated with VKA in three French dialysis units between 1st January and 31st December 2022. Patients are followed with weekly INR. Variables collected included over twelve months the number of INR tests, their percentage within target, above target and below target, and number of VKA dose adjustment. Bleedings, transfusions, thrombotic events and antibiotic use were recorded. Linear regression analysis evaluated factors associated with number of VKA dose adjustment per year. This study was conducted in concordance with the Declaration of Helsinki 1975. Results Out of 160 HD patients, 45 (28.1%) were on VKA for paroxysmal or chronic atrial fibrillation. Their characteristics are summarized in Table 1. A total of 2609 INR tests were performed over a year with a mean of 57.9±18.6 per patient. The median number of VKA dose adjustment per year was 11 (8, 13). A significant correlation was found between the number of antibiotics and number of VKA dose adjustment (Spearman Rho = 0.360, p = 0.015). In univariate regression analysis, factors associated with higher numbers of dose adjustment were diabetes, sevelamer and blood flow (Table 2). Bleeding was not significantly different between those with high versus low VKA dose adjustment. Conclusion In this study, 22% of tests led to VKA dose adjustment. Patients with diabetes, on sevelamer, treated with antibiotics and with lower serum albumin needed frequent INR testing more than once monthly. These results could be helpful in contexts with limited resources.