Influence of dabigatran, rivaroxaban or apixaban treatment on hemostasis point-of-care testing (POCT) in patients with atrial fibrillation.

The rapid monitoring of anticoagulant effect of new oral anticoagulants (NOA) – dabigatran, rivaroxaban, apixaban – might be required in specific conditions to prevent the risk of bleedings or thrombosis. As clinical application of NOAs is gradually growing, it might be noteworthy to know their influence on hemostasis POCT. This study was aimed to assess the NOA effect on the POC parameters in patients with atrial fibrillation. Whole blood was taken just before (TTrough) and 3 hrs after the administration (Tmax) (TTrough: 110 – dabigatran, 57 – rivaroxaban and 30 – apixaban patients; Tmax, 62, 18 and 18 patients). ACT, aPTT, PT (Hemochron Signature/Elite, ITC, USA), thromboelastometry (ROTEM, TEM Int, Germany) and platelet function analysis (Innovance-PFA-200, Siemens, Germany) were performed. Dabigatran and rivaroxaban plasma levels were measured with Hemoclot technique and Biophen DXaI (HyphenBiomed, France), respectively. At TTrough, patients showing normal clotting times were: ACT, 2/110 (dabigatran), 9/57 (rivaroxaban) 7/30 (apixaban); aPTT, 5/57 (rivaroxaban), 5/30 (apixaban). Rivaroxaban or apixaban patients showed prolonged PT. At Tmax, all patients showed ACT, aPTT and PT significantly prolonged (p<0.001), except for 3/18 (ACT) and 5/18 (aPTT) patients on apixaban. Dynamic parameters of ROTEM tests (EXTEM, INTEM, ECATEM) were significantly prolonged (p<0.001); no change was observed in PFA-200-CTs. Significant relationships were observed between plasma drug concentration and clotting parameters (at least, p=0.01). NOAs exhibit distinct effects on clotting and platelet function POCT. Use of clotting POCT might provide information in emergency clinical setting to evaluate the impact of these drugs on clotting system, when rapid medical decision should be taken.