Global thromboelastometry in patients receiving direct oral anticoagulants: the RO-DOA study.

Rapidly available tests might be useful to measure the anticoagulant effect of direct oral anticoagulants (DOAs) in emergency situations as bleedings, surgery, or before thrombolysis. The aim of this study was to assess the effects of DOAs on global thromboelastometry (ROTEM). Coagulation parameters assessed at peak and trough in patients with non-valvular atrial fibrillation receiving apixaban, dabigatran or rivaroxaban at steady-state (patients) were compared to those of healthy volunteers (controls). Citrated blood samples were tested by ROTEM using diluted EXTEM assay, with and without the addition of an anti-FXa catcher, and using ECATEM-B, with and without the addition of an anti-FIIa catcher. Overall 30 patients (10 for each DOA) and 15 controls were included. The mean clotting time (CT) of patients at peak and trough were significantly higher compared to controls. The mean CT was significantly shortened after the addition of the anti-FXa catcher to apixaban (p = 0.005 for peak and p = 0.009 for trough) and to rivaroxaban samples (p = 0.005 for both peak and trough) and after the addition of anti-FIIa cather to dabigatran samples (p = 0.005 for both peak and trough). ROC curve analyses showed a good accuracy for CT and for CT/CT + catcher (CTc) in measuring dabigatran anticoagulant activity (AUC 1.000 and 0.993, respectively); for CT, CT/CTc and clot formation time (CFT)/CFT + catcher (CFTc) in measuring both apixaban activity (0.917, 0.880 and 0.880, respectively) and rivaroxaban activity (0.973, 0.987 and 0.860, respectively). In this study the use of ad-hoc designed reagents and catcher molecules was able to accurately identify DOAs activity at ROTEM.