Specific Point-of-Care Testing of Coagulation in Patients Treated with Dabigatran

Fig. 1. Diagnostic accuracy of point-of-care ecarin clotting time (POC-ECT), laboratory-based ECT, and laboratory-based Biophen Direct Thrombin Inhibitor (BDTI) assay. Scatter plots illustrate the correlation between dabigatran plasma concentrations determined by ultra-performance liquid chromatography/tandem mass spectrometry and ( A ) POC-ECT with whole blood (WB), ( B ) citrated blood (CB), ( C ) citrated plasma (CP) as well as ( D ) calibrated laboratory-based (lab.) ECT, and ( E ) calibrated laboratory-based (lab) BDTI. Green shaded bars indicate the treatment-relevant dabigatran plasma concentration thresholds of 30 ( darker ) and 50 ng/mL ( lighter ). Horizontal gray lines indicate suggested optimal cut-offs providing >95% sensitivity for detection of samples containing >30 ( solid ) and >50 ng/mL ( dashed ) of dabigatran. Diagonal black lines indicate regression lines with their respective equations and the squared Pearson's correlation coefficient ( R 2 ) to be found in the upper left corner of the diagrams.

Fig. 2. Comparison of agreement with ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) between calibrated point-of-care ecarin clotting time (POC-ECT) and two calibrated laboratory-based anti-IIa assays. Bland–Altman plots are used to display the agreement level between UPLC-MS/MS and calibrated POC-ECT: ( A ) all data and ( B ) 0–100 ng/mL; calibrated laboratory-based (lab.) ECT: ( C ) all data and ( D ) 0–100 ng/mL; as well as calibrated laboratory-based (lab.) Biophen Direct Thrombin Inhibitor (BDTI) assay: ( E ) all data and ( F ) 0–100 ng/mL; all measurements were performed using citrated plasma. Gray horizontal lines indicate a distance of 1.96 standard deviations ( short-dashed ) from the mean ( long-dashed ). Green shaded bars indicate the dabigatran plasma concentration treatment-relevant thresholds of 30 and 50 ng/mL. Diagonal red lines indicate regression curves with their respective equations and the squared Pearson's correlation coefficient ( R 2 ) to be found in the upper left corner of the diagrams.