Whole blood coagulation assays ROTEM and T-TAS to monitor dabigatran treatment

Thromb Res. 2017 May;153:76-82. doi: 10.1016/j.thromres.2017.03.018. Epub 2017 Mar 18.

Abstract

Background: A rapid and reliable assessment of the dabigatran effect is desirable in dabigatran treated patients with uncontrolled bleeding or before acute surgery.

Objective: To 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).

Method: ROTEM using the reagents In-tem, Ex-tem, Fib-tem or low tissue factor concentration (TF), and T-TAS with the AR-chip (shear rate 600s-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 150mg BID.

Results: Median plasma dabigatran concentrations at trough were 86ng/mL (29-150) and post-dose (2.8h after ingestion) 175ng/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.

Conclusions: ROTEM 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.

Keywords: Atrial fibrillation; Dabigatran; Drug monitoring; Flow chamber system; Thromboelastography.

MeSH terms

  • Aged
  • Antithrombins / blood
  • Antithrombins / pharmacology
  • Antithrombins / therapeutic use*
  • Atrial Fibrillation / blood
  • Atrial Fibrillation / drug therapy*
  • Blood Coagulation / drug effects*
  • Blood Coagulation Tests / methods*
  • Dabigatran / blood
  • Dabigatran / pharmacology
  • Dabigatran / therapeutic use*
  • Drug Monitoring / methods*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Point-of-Care Systems*
  • Thrombelastography / methods
  • Whole Blood Coagulation Time / methods

Substances

  • Antithrombins
  • Dabigatran