Abstract Number: PB2475
Meeting: ISTH 2020 Congress
Theme: Venous Thromboembolism and Cardioembolism » VTE Treatment
Background: Apixaban, unlike Vitamin-K antagonists, has a predictable effect and does not require biological control routinely. However, estimation of plasmatic concentration could be useful in individual dose adjustment, certain clinical circumstances and selected patients.
Aims:
1) Evaluate biological effect of apixaban with chromogenic anti-Xa test with calibrators for apixaban and heparin
2) Analyze correlation between both techniques.
3) Study application of a correction factor to estimate plasmatic concentration of apixaban based on anti-Xa activity.
Methods: 100 patients anticoagulated with apixaban were included (1Jan2018 2018-31Dec2018). Anti Xa activity (HemosIL Liquid anti-Xa) and a chromogenic assay to estimate apixaban concentration with specific calibrator (TECHNOVIEW apixaban Cal High Set) in the ACL TOP coagulometer (Instrumentation Laboratory, MA, USA), were determined. Pearson´s coefficient was calculated to assess the correlation between both techniques. A linear regression was performed to calculate the estimated levels of apixaban based on anti-Xa activity. P< 0.05 were considered significant.
The results were validated in a prospective cohort of patients anticoagulated with apixaban (n=35) (1Jan2019-30Apr2019). Estimated apixaban levels (linear regression) and apixaban levels obtained with specific calibrator were compared. Statistical analysis was performed with SPSS version 19.0 for Windows (SPSS, Chicago, IL, USA).
Results: An excellent correlation was observed between the anti-Xa activity and the estimated levels of apixaban (Pearson´s test: r=0.930, p< 0.001). Using linear regression (y=140.54x + 1.3356) we estimated apixaban levels and compared them with those obtained with a specific calibrator. The median difference was 8.9 ng/ml. Figure 1.
Conclusions: Plasmatic concentration of apixaban can be estimated by applying a correction factor to the anti-Xa activity (calibrated for heparins). Anti Xa chromogenic assay with specific calibrators for apixaban is a quantitative method and easy to perform, allowing to determine estimated plasma concentration. This approach would reduce the cost of reagents, although a different correction factor needs to be calculated in each laboratory.
To cite this abstract in AMA style:
Velasco D, Vidal R, Garcia Raso A, Martin S, Llamas P. Correlation between Anti-Xa Activity and Plasmatic Levels of Apixaban [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/correlation-between-anti-xa-activity-and-plasmatic-levels-of-apixaban/. Accessed March 21, 2024.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/correlation-between-anti-xa-activity-and-plasmatic-levels-of-apixaban/