Full Length ArticleWhole blood coagulation assays ROTEM and T-TAS to monitor dabigatran treatment

- Tests to assess dabigatran levels in acute situations would be valuable.
- ROTEM variable CT correlated strongly with dabigatran concentrations in patients.
- T-TAS variables detected dabigatran effects but correlated weaker to drug levels.
- ROTEM CT could be useful for measurements of dabigatran in emergency situations.

BackgroundA rapid and reliable assessment of the dabigatran effect is desirable in dabigatran treated patients with uncontrolled bleeding or before acute surgery.ObjectiveTo evaluate how the viscoelastic point-of-care test Rotational thromboelastometry (ROTEM) and Total Thrombus-formation system (T-TAS), which studies thrombus formation under flowing conditions, correlate with dabigatran concentrations in patients with atrial fibrillation (AF).MethodROTEM using the reagents In-tem, Ex-tem, Fib-tem or low tissue factor concentration (TF), and T-TAS with the AR-chip (shear rate 600 s− 1, representing flow in large arteries) were investigated in whole blood samples. Plasma concentrations were determined by mass spectrometry (LC-MS/MS) at trough and post-dose in 30 patients on dabigatran 150 mg BID.ResultsMedian plasma dabigatran concentrations at trough were 86 ng/mL (29-150) and post-dose (2.8 h after ingestion) 175 ng/mL (67-490). The ROTEM clotting time (CT) correlated strongly with dabigatran concentrations when activated with the reagents Ex-tem (r = 0.92, p < 0.01) and Fib-tem (r = 0.93, p < 0.01), while with In-tem and low TF the correlation was weaker (r = 0.72 and r = 0.36, p < 0.01). There were significant but weaker correlations also between dabigatran concentrations and T-TAS variables (r-values 0.39-0.41, p < 0.01), aPTT (r = 0.70, p < 0.01) and PT-INR (r = 0.43, p < 0.01) respectively.ConclusionsROTEM Ex-tem and Fib-tem CT shows a strong correlation with dabigatran concentrations in real-life AF-patients, and results are obtained within minutes. This could make ROTEM useful in acute situations. T-TAS detect differences in hemostasis caused by dabigatran, but the relationships to plasma concentrations of dabigatran are weaker than for ROTEM CT with the settings used in this study.