title: Thrombelastography detects dabigatran at therapeutic concentrations in vitro to the same extent as gold-standard tests.
abstract: OBJECTIVE
  Dabigatran is an oral anticoagulant approved for treatment of non-valvular atrial fibrillation, deep venous thrombosis (DVT), pulmonary embolism and prevention of DVT following orthopedic surgery. Monitoring of the dabigatran level is essential in trauma and bleeding patients but the available plasma-based assays may not sufficiently display its hemostatic effect. This study investigated the in vitro effect of different concentrations of dabigatran on whole blood thrombelastography (TEG) and its correlation to the specific but time-consuming plasma-based tests Hemoclot and Ecarin Clotting Time (ECT).
  
  
  METHODS
  Blood was collected from 8 healthy donors (two females, six males) with a median age of 46 years and it was spiked with dabigatran to a range of plasma concentrations (0, 50, 100, 200 and 400 ng/ml) covering the therapeutic level.
  
  
  RESULTS
  Mean TEG R at 0 ng/ml=5.963 min, 50 ng/ml=7.425 min, 100 ng/ml=8.425 min, 200 ng/ml=9.775 min, 400 ng/ml=11.813 min. A significant overall increase (p=0.001) in TEG reaction time (R) was found across increasing dabigatran concentrations i.e. 0 vs 50 vs 100 vs 200 vs 400 ng/ml (p<0.000 p=0.027 p=0.026, p=0.005, respectively). TEG R correlated strongly with Hemoclot (R(2)=0.891, p<0000) and ECT (R(2)=0.914, p<0.000) and Hemoclot and ECT were strongly inter-correlated (R(2)=0.978, p<0.000).
  
  
  CONCLUSIONS
  The whole blood viscoelastic assay TEG R displayed linearity towards fixed concentrations of dabigatran and correlated strongly to the current gold-standard tests Hemoclot and ECT, for assessing dabigatran. TEG R is applicable as a rapid and precise whole blood monitoring test for dabigatran treated patients in the emergency setting.
authors.affiliation: Section for Transfusion Medicine, Capital Region Blood Bank, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark. Electronic address: sacha@solbeck.dk.
authors.forename: Sacha
authors.initials: S
authors.lastname: Solbeck
authors.affiliation: Section for Transfusion Medicine, Capital Region Blood Bank, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark.
authors.forename: Sisse R
authors.initials: SR
authors.lastname: Ostrowski
authors.affiliation: Section for Transfusion Medicine, Capital Region Blood Bank, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark; Department of Anaesthesiology, Centre of Head and Orthopaedics, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Jakob
authors.initials: J
authors.lastname: Stensballe
authors.affiliation: Section for Transfusion Medicine, Capital Region Blood Bank, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark; Department of Surgery, University of Texas Health Medical School, Houston, TX, USA.
authors.forename: Pär I
authors.initials: PI
authors.lastname: Johansson
mesh_terms: D000328:Adult; D000991:Antithrombins / Q000097:blood* / Q000627:therapeutic use; D001777:Blood Coagulation / Q000187:drug effects / Q000502:physiology; D002318:Cardiovascular Diseases / Q000097:blood / Q000188:drug therapy; D000069604:Dabigatran / Q000097:blood* / Q000627:therapeutic use; D016903:Drug Monitoring / Q000379:methods* / Q000592:standards; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012015:Reference Standards; D013916:Thrombelastography / Q000379:methods* / Q000592:standards
chemical_list: D000991:Antithrombins; D000069604:Dabigatran
keywords: Anticoagulation; Dabigatran; Ecarin clotting time; Thrombelastography; Thrombin time