This is a PDF fle of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its fnal form. Please note that during the production process errors may be discovered which could afect the content, and all legal disclaimers that apply to the journal pertain. Accepted Manuscript TH Open Measurement of Anticoagulation in Patients on Dabigatran, Rivaroxaban and Apixaban Therapy by Novel Automated Thrombelastography Ramin Artang, Joao Dias, Mark Walsh, Kevin P Bliden, Jørn Dalsgaard Nielsen, Maren Anderson, Brain Thurston, Udaya S. Tantry, Jan Hartmann, Paul A Gurbel. Afliations below. DOI: 10.1055/a-1692-1415 Please cite this article as: Artang R, Dias J, Walsh M et al. Measurement of Anticoagulation in Patients on Dabigatran, Rivaroxaban and Apixaban Therapy by Novel Automated Thrombelastography. TH Open 2021. doi: 10.1055/a-1692-1415 Confict of Interest: JDD and JH were employees of Haemonetics Corporation at the time of the study. This study was supported by Haemonetics Corporation (Boston, Massachusetts). This study was supported by Haemonetics Corporation (http://dx.doi.org/10.13039/100015135) Trial registration: NCT02798328, ClinicalTrials.gov (http://www.clinicaltrials.gov/), Prospective observational multi-center study Abstract: Background: Direct-acting oral anticoagulants (DOACs) do not require monitoring. Measurement of DOAC efect would be useful in the event of bleeding, trauma, and thromboembolism while on anticoagulation. We evaluated the efectiveness of the investigational DOAC assays on the TEG®6s Hemostasis Analyzer to assess the anticoagulant efect of DOACs in patients treated for atrial fbrillation or DVT. Methods: Patients on treatment for a minimum of 7 days with standard doses of dabigatran, rivaroxaban and apixaban were included. DOAC plasma concentrations and TEG®6s R-time were measured and correlated. The sensitivity, specifcity and ne- gative predictive value (NPV) of R-time to detect DOAC concentrations of ≥ 30, ≥ 50 and ≥ 100 ng/mL were calculated. Results: 189 Subjects were included, (n=50) on apixaban, (n= 62) on rivaroxaban, (n=53) on dabigatran and (n=24) on no DOAC were studied. Using the direct thrombin inhibitor (DTI) channel, R-time demonstrated strong linear correlation with dabigatran levels (r = 0.93, p < 0.0001). Using the anti-factor Xa (AFXa) channel, R-time demonstrated strong non-linear correlation with rivaroxaban and apixaban levels (rs = 0.92 and 0.84 respectively, p < 0.0001 for both). R-time revealed strong sensitivity and NPV in detecting low DOAC levels for the predefned concentrations. Conclusion: R-time measured by TEG®6s DOAC Specifc cartridge has a strong correlation with concentrations of the most commonly used DOACs, with high sensitivity and NPV for detecting lower drug levels that are considered clinically relevant for patients in need of antidote, or prior to urgent surgery. Further studies to determine the relation of R-time to clinical outcomes are warranted. Corresponding Author: Ramin Artang, Essentia Health Saint Mary‘s Medical Center, Cardiology, 407 East 3rd Street, 55805-1984 Duluth, United States, ramin_ artang@yahoo.com, ramin.artang@essentiahealth.org Afliations: Ramin Artang, Essentia Health Saint Mary‘s Medical Center, Cardiology, Duluth, United States Ramin Artang, Copenhagen University Hospital, Cardiology, Copenhagen , Denmark Submission Date: 2021-08-23 Accepted Date: 2021-11-04 Publication Date: Accepted Manuscript This article is protected by copyright. All rights reserved. 2021-11-09