Figure 3.

Influence of LMWHs on the estimation of rivaroxaban plasma concentration with the 3 chromogenic anti-Xa assays. Biophen DiXaI LOW and STA LAX are influenced by the presence of LMWH. Up to 0.12 IU/mL, Biophen DiXaI LOW performs better than Biophen DiXaI but above this threshold, the overestimation of the Biophen DiXaI LOW is higher than that of Biophen DiXaI which is not influenced by LMWH at these concentrations. Samples with LMWH concentrations below the LOQ of the heparin assay were not included. LMWH indicates low-molecular-weight heparin; LOQ, limit of quantitation.