Anti-inflammatory effect of factor-Xa inhibitors in Japanese patients with atrial fibrillation.

Activated factor-X (FXa) plays an important role not only in the coagulation cascade, but also in pro-inflammatory responses. However, few data exist regarding the anti-inflammatory effect of FXa inhibitors in clinical practice. The aim of this study was to evaluate the anti-inflammatory and anti-atherosclerotic effects of FXa inhibitors in Japanese patients with non-valvular atrial fibrillation (NVAF). Eighty-three patients with NVAF were treated with FXa inhibitors from March 2013 to March 2015 at our institution. Of these, 55 patients who were not pretreated with warfarin or dabigatran (rivarixaban in 23 patients and apixaban in 32) were included in this study. We measured various inflammatory and coagulation markers at baseline and at 6 months after treatment. Plasma concentrations of pentraxin 3 (PTX3) (from 2.45 ± 1.31 to 1.97 ± 1.00 ng/mL, p = 0.0009) and fibrin and fibrinogen degradation products (FDP) D-dimer (from 1.18 ± 0.70 to 0.74 ± 0.32 μg/mL, p < 0.0001) decreased, while those of TM (from 2.9 ± 0.8 to 3.2 ± 0.9 FU/mL, p = 0.003) increased significantly at 6 months. Interestingly, change of each marker denoted the same tendency in both rivaroxaban and apixaban. In conclusion, the present study suggests that FXa inhibitors have not only an anti-coagulant effect but also anti-inflammatory effects in patients with NVAF. Further large-scale prospective study is necessary to evaluate whether changes in these markers will be associated with a lower risk for future cardiovascular events.