Dielectric blood coagulometry to evaluate coagulation activity in patients prescribed factor Xa inhibitors undergoing...

Dielectric blood coagulometry (DBCM) is a coagulation test based on dielectric permittivity. We recently developed a new cartridge to evaluate the anticoagulation effect of factor Xa inhibitors and investigated the usefulness of this system in the clinical setting. Here, we evaluate the relationship among the coagulation time measured by DBCM, plasma concentrations of factor Xa inhibitors, and peak thrombin generation using blood samples from patients prescribed factor Xa inhibitors undergoing elective surgery.

Whole-blood samples were collected at the preoperative visit and after anesthetic induction in the operating room, and our cartridge was used to measure the coagulation time by DBCM. Plasma was used to evaluate thrombin generation and to perform in vitro quantification of factor Xa inhibitors. Spearman's correlation was used to analyze correlations, and receiver operating characteristic (ROC) curves were used to evaluate diagnostic performance.

The DBCM coagulation time correlated with plasma factor Xa inhibitor concentrations (Rs = 0.87 for apixaban [n = 57, P < 0.001]; Rs = 0.91 for rivaroxaban [n = 49, P < 0.001]) and peak thrombin generation (Rs = -0.80 for apixaban [n = 57, P < 0.001]; Rs = -0.84 for rivaroxaban [n = 49, P < 0.001]). Samples with factor Xa inhibitor concentrations <30 ng/mL had an area under the ROC curve of 0.98 (95 % confidence interval 0.96-1.0) for apixaban and 0.99 (95 % confidence interval 0.99-1.0) for rivaroxaban.

DBCM was a useful point-of-care test to evaluate the anticoagulation effect induced by factor Xa inhibitors.