DOAC Dipstick Testing Can Reliably Exclude the Presence of Clinically Relevant DOAC Concentrations in Circulation

Area of Science:

• Clinical Pharmacology
• Diagnostic Testing
• Pharmacokinetics

Background:

• Determining clinically relevant plasma levels of direct oral anticoagulants (DOACs) is crucial in specific clinical scenarios.
• Existing methods for DOAC quantification can be complex or time-consuming, necessitating simpler diagnostic approaches.

Purpose of the Study:

• To evaluate the utility of qualitative urine testing using DOAC Dipstick to exclude significant plasma concentrations of DOACs (≥30 ng/mL).
• To determine the negative predictive value (NPV) and other diagnostic parameters of the DOAC Dipstick for direct factor Xa inhibitors (DXIs) and direct thrombin inhibitors (DTIs).

Main Methods:

• A prospective single-center cohort study included 128 patients treated with apixaban, rivaroxaban, or dabigatran.
• DOAC urine testing was performed using DOAC Dipstick and compared with plasma concentrations measured by chromogenic substrate assays.
• Logistic regression analysis identified optimal plasma concentration thresholds for DXI and DTI detection.

Main Results:

• DOAC Dipstick demonstrated 100% NPV and sensitivity for excluding DOACs at plasma concentrations ≥30 ng/mL.
• At optimized thresholds (≥14 ng/mL for DXI, ≥19 ng/mL for DTI), diagnostic performance improved significantly, with values ranging from 86% to 100%.
• Visual DOAC Dipstick analysis showed 100% agreement with the optoelectronic DOASENSE Reader.

Conclusions:

• DOAC Dipstick urine testing is a reliable method to exclude the presence of DOACs at plasma concentrations >14 ng/mL for DXIs and >19 ng/mL for DTIs.
• The study supports the use of DOAC Dipstick as a valuable tool for rapid assessment of DOAC presence in clinical practice.
• Further studies are needed to confirm its performance in detecting lower DOAC plasma concentrations.