Abstract 3353

The new oral direct coagulation inhibitor rivaroxaban prolongs coagulation times of various coagulation assays in a concentration-dependent manner. A point of care determination of the anticoagulant effect of rivaroxaban would improve patient care and patient's safety in case of overdose of rivaroxaban. We have analysed intraindividual coefficients of variations (CV) of the Coagucheck XS compared to the STA Neoplastin Plus and STA Rotachrom heparin assays.

Rivaroxaban was spiked to whole blood and plasma from 10 healthy donors (50ng/ml, 200 ng/ml, and 600 ng/ml). Coagulation times and ratios were measured by means of the Coagucheck XS (recombinant human thromboplastin) from whole blood and plasma samples and STA Neoplastin Plus (rabbit brain thromboplastin). The concentration of rivaroxaban was determined using the factor Xa specific chromogenic substrate STA Rotachrom heparin assay. The intraindividual CVs were calculated from 10 determinations at 10 days for the methods at all concentrations of rivaroxaban.

Rivaroxaban prolonged coagulation times of all coagulation assays. The ratios increased from 0 ng/ml to 600 ng/ml rivaroxaban from 1.0 (50 ng/ml) to 1.20 (200 ng/ml) and 1.63 (600 ng/ml) using the whole blood Coagucheck XS method, from 1.0 to 1.33 to 1.85 using plasma on Coagucheck XS, and from 1.0 to 1.51 to 1.80 using the STA Neoplastin Plus assay, respectively. Values of the STA Rotachrom assay were used for comparison of the CVs of the methods. CVs were calculated from the original data (seconds or optical density). CVs were calculated from the intraindividual variation over 10 days for every volunteer. The median, minimum and maximum values are displayed as well as the p-value for the difference of the CVs between methods for every concentration of rivaroxaban (Kruskal Wallis test).

MethodRivaroxaban: 0ng/ml50ng/ml200ng/ml600ng/ml
Cogucheck XS CV median 1.04 0.99 1.04 0.87 
whole blood min-max 0.38–1.70 0.65–1.43 0.37–1.68 0.40–1.40 
Coagucheck XS CV median 1.08 1.01 1.04 1.80 
plasma min-max 0.83–2.38 0.46–2.80 0.61–2.36 0.52–3.17 
Neoplastin Plus CV median 1.83 1.74 3.97 4.30 
 min-max 1.06–2.17 1.33–2.67 1.75–4.83 2.02–6.09 
Rotachrom CV median 1.48 1.84 3.97 2.99 
 min-max 0.96–2.39 0.97–2.39 2.46–6.49 2.08–6.15 
p-value  0.0115 0.0011 <.0001 <.0001 
MethodRivaroxaban: 0ng/ml50ng/ml200ng/ml600ng/ml
Cogucheck XS CV median 1.04 0.99 1.04 0.87 
whole blood min-max 0.38–1.70 0.65–1.43 0.37–1.68 0.40–1.40 
Coagucheck XS CV median 1.08 1.01 1.04 1.80 
plasma min-max 0.83–2.38 0.46–2.80 0.61–2.36 0.52–3.17 
Neoplastin Plus CV median 1.83 1.74 3.97 4.30 
 min-max 1.06–2.17 1.33–2.67 1.75–4.83 2.02–6.09 
Rotachrom CV median 1.48 1.84 3.97 2.99 
 min-max 0.96–2.39 0.97–2.39 2.46–6.49 2.08–6.15 
p-value  0.0115 0.0011 <.0001 <.0001 
View Large

The point of care monitor Coagucheck XS using whole blood determines with the highest accuracy and precision the amount of rivaroxaban. The method may be used to screen for overdose in patients on treatment with rivaroxaban.

Disclosures:

Harenberg:Roche Diagnostics: Research Funding.

Topics:
coefficient of variation, prothrombin time, rivaroxaban, chorionic villi sampling, cyclical vomiting syndrome, heparin, overdose, thromboplastin, anticoagulants, factor xa

Author notes

*

Asterisk with author names denotes non-ASH members.

© 2011 by The American Society of Hematology
2011
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