Thromb Haemost 2013; 110(03): 543-549
DOI: 10.1160/TH13-03-0202
Blood Coagulation, Fibrinolysis and Cellular Haemostasis
Schattauer GmbH

Comparison of calibrated dilute thrombin time and aPTT tests with LC-MS/MS for the therapeutic monitoring of patients treated with dabigatran etexilate

Jonathan Douxfils
1  Department of Pharmacy, Namur Thrombosis and Hemostasis Center (NTHC), Namur Research Institute for LIfe Sciences (NARILIS), University of Namur, Belgium
,
Jean-Michel Dogné
1  Department of Pharmacy, Namur Thrombosis and Hemostasis Center (NTHC), Namur Research Institute for LIfe Sciences (NARILIS), University of Namur, Belgium
,
François Mullier
1  Department of Pharmacy, Namur Thrombosis and Hemostasis Center (NTHC), Namur Research Institute for LIfe Sciences (NARILIS), University of Namur, Belgium
2  Hematology Laboratory, Namur Thrombosis and Hemostasis Center (NTHC), Namur Research Institute for LIfe Sciences (NARILIS), CHU UCL Mont-Godinne-Dinant, Université Catholique de Louvain, Belgium
,
Bernard Chatelain
2  Hematology Laboratory, Namur Thrombosis and Hemostasis Center (NTHC), Namur Research Institute for LIfe Sciences (NARILIS), CHU UCL Mont-Godinne-Dinant, Université Catholique de Louvain, Belgium
,
Yuko Rönquist-Nii
3  Department of Clinical Pharmacology, Karolinska University Hospital and Clinical Pharmacology Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
,
Rickard E. Malmström
3  Department of Clinical Pharmacology, Karolinska University Hospital and Clinical Pharmacology Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
,
Paul Hjemdahl
3  Department of Clinical Pharmacology, Karolinska University Hospital and Clinical Pharmacology Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
› Author Affiliations
Further Information

Publication History

Received: 07 March 2013

Accepted after minor revision: 27 May 2013

Publication Date:
22 November 2017 (online)

Summary

Ways to monitor dabigatran etexilate (DE) therapy would be useful in certain situations. Functional assays such as aPTT or Hemoclot® Thrombin Inhibitor (HTI) have been proposed to evaluate dabigatran concentrations, but previous findings are based on in vitro studies and results must be confirmed in clinical samples. The aim of this study was to compare aPTT and HTI measurements with liquid chromatography- tandem mass spectrometry (LC-MS/MS) measurements of dabigatran in plasma samples from DE treated patients. Seventy-one plasma samples were included. aPTT was performed using STA-CKPrest® and SynthASil®. HTI was performed according to instructions from the manufacturer. The LC-MS/MS method utilised dabigatran- d3 as internal standard. The plasma concentration range was 0 to 645 ng/ml as measured by LC-MS/MS. Overall, the HTI and LC-MS/ MS analyses correlated well (r2=0.97). The Bland-Altman analysis showed a mean difference of 9 ng/ml (SD: 20 ng/ml). However, the HTI performed poorly at concentrations <50 ng/ml. LC-MS/MS was sensitive (limit of quantification 1.1 ng/ml) and specific for dabigatran. The aPTT methods did not correlate well with plasma concentrations measured by LC-MS/MS (r2 = 0.59 with SynthASil® and 0.50 with STACKPrest ®). In conclusion, the poor sensitivity, the important inter-individual variability, and the poor correlation with LC-MS/MS preclude the use of aPTT to estimate dabigatran concentrations. Due to its small inter-individual variability and good agreement with LC-MS/MS measurements, we recommend the use of HTI assays to rather accurately estimate concentrations of dabigatran <50 ng/ml. Quantification of lower dabigatran levels in DE-treated patients requires the “reference” LC-MS/MS method.