Comparison of anti-inflammatory effects of rivaroxaban vs. dabigatran in patients with non-valvular atrial fibrillation (RIVAL-AF study): multicenter randomized study.

Some experimental studies have shown that direct oral anticoagulants (DOACs) have anti-inflammatory effects. However, the interval changes in inflammatory markers in patients with non-valvular atrial fibrillation (AF) who receive DOACs remain unknown. Between July 2013 and April 2014, a total of 187 AF patients randomly assigned to receive rivaroxaban (n = 91) or dabigatran (n = 96) were assessed for eligibility. The levels of the following inflammatory markers were serially evaluated: high-sensitivity C-reactive protein, pentraxin-3, interleukin (IL)-1ß, IL-6, IL-18, tumor necrosis factor-α, monocyte chemotactic protein-1, growth and differentiation factor-15, and soluble thrombomodulin (sTM). The aim in this study was to evaluate the anti-inflammatory effects of rivaroxaban and dabigatran in patients with AF, in addition to the impact of markers on bleeding events. Finally, 117 patients (rivaroxaban: n = 55, dabigatran: n = 62) were included in the analysis at 12 months. Although the interval changes in sTM levels tended to be greater in the dabigatran group [0.3 (0-0.7) vs. 0.5 (0-1.0) FU/ml, p = 0.061], there were no significant differences in the interval changes in any inflammatory marker between 2 groups. There were no significant differences in bleeding events between 2 groups. The interval changes in sTM levels were significantly greater in patients with bleeding compared with those without [0.8 (0.5-1.3) vs. 0.4 (- 0.1-0.8) FU/ml, p = 0.017]. There were no significant differences in the interval changes in any inflammatory marker between rivaroxaban and dabigatran treatments in patients with AF. The increased levels of sTM after DOACs treatment might be related to bleeding events.

Lipoxygenase products regulate nitric oxide and inducible nitric oxide synthase production in interleukin-1beta stimulated vascular smooth muscle cells.

In cultured vascular smooth muscle cells (VSMCs), interleukin-1beta (IL-1beta) stimulates inducible nitric oxide synthase (iNOS) expression and nitric oxide (NO) production. IL-1beta also activates phospholipase A2 (PLA2), and induces lipoxygenase (LOX) and cyclooxygenase-2 (COX-2). The present study investigated whether these metabolites are involved in the regulation of IL-1beta-induced NO production and iNOS expression. Pretreatment with ONO-RS-082, the secretory PLA2 (sPLA2) inhibitor, at 1 to 10 micromol/l reduced IL-1beta-stimulated nitrite production and iNOS expression. Nordihydroguaiaretic acid (NDGA, 1 to 10 micromol/l), the LOX inhibitor, also reduced IL-1beta (10 ng/ml)-stimulated nitrite production and iNOS expression in a dose-dependent manner. Exogenous 12(S)-hydroxyeicosatetraenoic acids (HETE) enhanced the IL-1beta-stimulated nitrite production and iNOS expression. On the other hand, the COX inhibitors, indomethacin and NS-398, had little effect on nitrite production or iNOS expression. These results suggest that LOX products play important roles in the regulation of stimulus-induced NO production in VSMCs.