OC 15.1 - A novel Point-of-Care whole blood portable analyzer for direct oral anticoagulant monitoring

Background: Direct oral anticoagulants (DOACs) do not require routine laboratory monitoring. However, in specific clinical situations and for particular patient populations, testing may be important for patient management, e.g. in emergency or surgical situations. A new whole blood Point-of-Care (POC) coagulation analyzer (microDOAC) has been developed to fulfill this unmet clinical need. This highly innovative instrument is based on microfluidic technology and has key characteristics to allow patient real time monitoring in multiple clinical settings: fast turnaround time ( < 2min), handheld device, user-friendly and connectivity/patient traceability capabilities.

Aims: To assess microDOAC test sensitivity and specificity to detect DOAC at selected clinically relevant concentration thresholds.

Methods: Normal donor whole blood samples obtained by venipuncture in a plastic tube without anticoagulant were spiked with increasing DOAC concentrations (0-500 ng/mL) and tested in the microDOAC chip. The remaining volume was appropriately citrated for measuring DOAC levels by anti-FXa activity (Diagnostica Stago, France). microDOAC POC is based on a clotting time assay. Receiver operator characteristic (ROC) curves were used to identify the assay values (in seconds) that best discriminate DOAC levels ≥30, ≥50 or ≥75 ng/mL; additionally, sensitivity, specificity and agreement values were calculated.

Results: 160 apixaban or rivaroxaban spiked samples were tested (80 samples ranging 0-100 ng/mL; 80 samples from 100-500 ng/mL). A ROC curve (Fig. 1) was generated to determine sensitivity and specificity at the clinically relevant DOAC concentrations where the area under the curve (AUC) was 0.998, 0.995 and 0.999, respectively. Both sensitivity and specificity values of microDOAC test for apixaban samples (Table 1) were high (>96%) at clinically relevant cut-offs. Similar results were obtained with rivaroxaban samples.

Conclusion(s): We have developed a lab-quality specific assay in a POC device, sensitive to clinically relevant DOAC levels or a selected cut-off of interest which are critical in emergency situations.