In this experimental study, Dias et al. investigated whether thrombelastography (TEG) could detect and differentiate between the two different classes of NOACs, thrombin inhibitors (dabigatran) and factor Xa inhibitors (rivaroxaban and apixaban), in low, normal and high doses using spiked blood samples from healthy volunteers.
The main findings were that both R time and TMRTG parameters in the kaolin TEG test were sensitive to dabigatran and apixaban whereas the ACT parameter in the rapidTEG test was sensitive to all 3 NOACs tested. In the presence of factor Xa inhibitors, the ecarin test induced signiﬁcant shortening of kaolin TEG R times whereas in the presence of direct thrombin inhibitors only a small and dose-dependent R time shortening was observed. Based on this, the authors conclude that the ecarin TEG test allows for discrimination between the presence of direct thrombin inhibitors and factor Xa inhibitors.
The results are in alignment with previous studies demonstrating that thrombelastography provides a quick and dose-dependent determination of the anticoagulant effects of dabigatran whereas detection of the anticoagulant effects of rivaroxaban and apixaban requires application of reagents that test both the extrinsic and intrinsic pathways (rapidTEG).
The clinical relevance of this study is that it emphasises that thrombelastography applied in the acute care setting can provide a quick and reliable determination of the anticoagulant effects of dabigatran and, if tested by rapidTEG, also rivaroxaban and apixaban.
– Sisse Rye Ostrowski