Thrombelastography detects dabigatran at therapeutic concentrations in vitro to the same extent as gold-standard tests

BACKGROUND/OBJECTIVES: 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).

METHOD: Blood was collected from 8 healthy donors (two females, six males) with a median age of 46years and it was spiked with dabigatran to a range of plasma concentrations (0, 50, 100, 200 and 400ng/ml) covering the therapeutic level.

RESULTS: Mean TEG R at 0ng/ml=5.963min, 50ng/ml=7.425min, 100ng/ml=8.425min, 200ng/ml=9.775min, 400ng/ml=11.813min. 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 400ng/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).

CONCLUSION: 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.