4assay normalization depends on NOAC type, NOAC concentration, TF concentration and used thromboplastin reagent.
This table summary clearly shows that the applicability of a particular test in monitoring NOAC or VKA anticoagulation does not translate directly to applicability in reversal assessment. The PT remains the appropriate test when managing VKA anticoagulation. TGA may also be suitable, but this requires further validation. Specialty assays suited for NOAC monitoring (ecarin clotting time, ECT; thrombin time, TT; direct thrombin inhibitor assay, DTI; chromogenic factor Xa inhibitor assay, Xa-i) do not apply to reversal assessment. Monitoring NOAC reversal is feasible with PT, TEG/ROTEM and TGA. However, most readout parameters only show partial NOAC reversal. Global assays, in general, show low sensitivity to NOACs (see Table 2).