VPB0569 - Evaluation of the FibWave in Edoxaban and Healthy Samples, a Comparison with the APTT- and PT-based Clot Waveform Analysis

Background: Edoxaban is used for several thromboembolic diseases, known to impact coagulation assays and enhance FX-dependent fibrinolysis and plasmin generation. The activated partial thromboplastin time (APTT) and prothrombin time (PT) are routinely available, but the sensitivity depends on reagent. Beside them, the CWA and FibWave are coagulation assays based on the analysis of clot formation kinetics.

Aims: This study compares the FibWave to the APTT- and PT-based CWA and assesses the fibrinolytic activity in edoxaban and healthy samples.

Methods: APTT, PT and FibWave analysis were performed on 68 healthy individuals (23 men, 22 women not using combined hormonal contraception (no CHC) and 23 women using hormonal contraception (CHC) and 71 edoxaban samples (plasma samples were collected at Cthrough and/or Cmax. The APTT and PT were performed with SynthasIL and ReadiPlasTin. For the FibWave, the intrinsic and extrinsic pathways were assessed with diluted STA-PTT-Automate “FibIn” and with phospholipids (±4µM) plus tissue factor (±5pM) “FibEx”, respectively. The fibrinolysis activity was assessed with tissue plasminogen activator “FibtPA”. For edoxaban samples, concentration was measured using a calibrated chromogenic anti-Xa assay, Biophen® Direct Anti-Xa Inhibitor.

Results: Significant differences were only observed in clotting time between healthy individuals with FibEx. Interestingly, with FibEx and PT-based CWA, the women with hormonal contraception had a higher velocity, acceleration and deceleration of coagulation compared to the other groups (p <.05). Similarly, the fibrinolysis time and velocity were higher in women on CHC compared to men (p <.05).
Pearson’s correlation test showed significant correlations between clotting times from APTT/PT/FibEx /FibIn assays and chromogenic measurements. The clotting time from FibEx demonstrated a better correlation (r=0.89) than PT (r=0.79), aPTT (r=0.65) and FibIn (r=0.61). The fibrinolysis time was prolonged in Cmax compared to Cthrough (p <.05).

Conclusion(s): The FibEx methodology has better potential to reflect the global coagulation activity compared to APTT- and PT-based CWA in healthy and edoxaban samples.