Abstract Number: PB0394
Meeting: ISTH 2021 Congress
Background: Direct oral anticoagulants (DOAC) do not require routine laboratory monitoring but it is useful to know the impact on coagulation assays in order to interpret the results specially in emergency situations as bleeding or urgent perioperative management.
Aims: The objective of our study is to determnine de DOAC concentration with specific test in control patients under different DOAC treatment and compare the results with routine coagulation assays in different moments, plasma concentration at peak (3 hours after drug intake) and through (just before intake).
Methods: Samples from volunteers patients with non-valvular atrial fibrillation under DOAC treatmente were collected at peak and through plasma concentrations. For all samples prothrombine time (PT) with Tromborel and activated partial thromboplastin time (APTT) with Actin-FS were measured. For anti-Xa DOAC anti-Xa activity (heparin calibrated) with Innovance Heparine and plasma concentration with STA-Liquid anti-Xa (Stago) was quantified, for Dabigatran thrombin time (TT) with Thromboclotin and the specific test STA-ECAII (Stago) were used.
Results:
| APIXABAN n:15 Median (25th-75th percentile) |
RIVAROXABAN n:10 Median (25th-75th percentile) |
DABIGATRAN n:5 Median (25th-75th percentile) |
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| Through | Peak | Throuh | Peak | Through | Peak | |
| PT sec (normal range 10-14) |
13.1 (12.5-13.5) |
14.3 (13.5-14.8) |
12.8 (11.7-16.5) |
16.1 (15.5-24.2) |
15.6 (15.1-15.7) |
16.6 (16.3-17.8) |
| APTT ratio (normal range 0.8-1.2) |
1.15 (1.1-1.3) |
1.2 (1.1-1.2) |
1.1 (1.0-1.4) |
1.4 (1.3-1.7) |
1.7 (1.6-1.9) |
2.1 (1.8-2.2) |
| Anti-Xa IU/mL (heparin calibrated) |
0.56 (0.36-0.78) |
1.79 (1.25-2.01) |
0.25 (0.05-0.73) |
1.70 (1.63-1.75) |
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| Concentration ng/mL | 82 (66-106) |
223 (157-303) |
31 (11-73) |
228 (170-338) |
190 (158-205) |
300 (245-335) |
Results of coagulation test at through and peak moments under DOAC treatment
30 patients were included (59% males, median age 71 years. The results for different test are seen in Table 1. Under Dabigatran TT was uncoagulable for all samples, and all PT and APTT were pathological. The most statistical correlation test with ditrect FXa inhibitor was anti-Xa (heparin calibrated) specially at throug (Fig. 2).
Correlation between anti-Xa (heparin calibrated) and DOAC levels at through moments
Conclusions: The results of DOAC concentration are similar to literature except for Dabigatran which are higher maybe because few samples.
We confirm Dabigatran is the DOAC that most modifies coagulation assays specially APTT and Apixaban nearly no modifies them.
The quatification of DOAC levels in plasma is more informative and useful than other coagulation parameter. In case to measure low plasma concentrations specific test calibrated are required but if these are not available for direct FXa inhibitors a heparin-calibrated chromogenic assay can be indicative of clinically relevant levels of a ditrect FXa inhibitor.
To cite this abstract in AMA style:
Garcia-Donas G, García M, Bonete M, Rodríguez A. Laboratory Testing in Patients Treated with Direct Oral Anticoagulants: Our Experience [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/laboratory-testing-in-patients-treated-with-direct-oral-anticoagulants-our-experience/. Accessed October 1, 2023.« Back to ISTH 2021 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/laboratory-testing-in-patients-treated-with-direct-oral-anticoagulants-our-experience/