CODING FOR AN ANTICOAGULANT: SYSTEMATIC REVIEW OF PHARMACOGENETICS-GUIDED WARFARIN THERAPY ON THE THERAPEUTIC AND ADVERSE CLINICAL EVENTS ON PATIENTS WITH ATRIAL FIBRILLATION, PULMONARY EMBOLISM, AND DEEP VEIN THROMBOSIS

Background: Warfarin is an anticoagulant widely used to prevent thromboembolic events (TEs) in patients with various cardiovascular (CV) diseases. Pharmacogenomics (PGx)-guided testing is a growing method suggested to help predict warfarin dosing. A systematic review was performed to compare the incidence of thromboembolic events (TEs), bleeding events (BEs), time in therapeutic range (TTR), the proportion of time to therapeutic range (PTTR) and warfarin dose adjustments between PGx-guided warfarin therapy and standard of care (SOC) in patients with non-valvular atrial fibrillation (Afib), pulmonary embolism (PE), and deep vein thrombosis (DVT). Methods: Two reviewers independently searched MEDLINE, CINAHL, Web of Science, Embase, Cochrane Library and clinicaltrials.gov databases from October 2019-August2022 to identify studies. Abstracts were reviewed for outcomes of interest and patient demographics to identify patients present with International Normalized Ratio (INR) readings, TTR, PTTR, BEs and TEs. Results: From the database search, 28 articles were retrieved based on abstract screening. A total of 6 articles were ultimately selected for the systematic review. All articles found favor in the PGx-guided group in terms of TTR. There were findings favoring PTTR, decreased BEs, and fewer dose adjustments in the PGx-guided group. Conclusion: Results of the systematic review demonstrate that PGx-guided warfarin dosing may establish a longer TTR than SOC. In select patients, PGx-guided warfarin therapy may decrease PTTR, reduce BEs, and require fewer dose adjustments. There was no noted benefit in PGx-guided therapy to reduce TEs.