Abstract 14010: Synergistic Influence of Rivaroxaban on Platelets, Inflammation and Coagulation Biomarkers in Patients With CAD and/or PAD on Aspirin Therapy

Abstract

Background: Cardiovascular benefits of 2.5 mg twice daily rivaroxaban plus aspirin therapy (RIV+ASA) has been demonstrated in patients with arterial diseases. Hypothesis: RIV+ASA is associated with reduced platelet activation and plasma inflammation and coagulation activation markers in patients with CAD and/or PAD who were on ASA. Methods: In this open-label biomarker study, patients on 81 mg/day ASA were randomized to continue ASA or RIV+ASA for 12 weeks. We assessed ADP-, α-thrombin-, and tissue factor-induced platelet aggregation (PA) using conventional aggregometry, platelet-fibrin clot strength (PFCS) by INTEM (intrinsic pathway activator) and EXTEM (extrinsic pathway activator) using thromboelastometry, shear-induced PA by platelet function analyzer-100, D-dimer and fibrinogen using coagulation analyzer, hs-CRP and interleukin-6 using ELISA method at baseline, and four weeks and 12 weeks post-randomization. Results: Data was available in 9 patients with RIV + ASA and ten patients with ASA-only therapy. Most patients were male, Caucasians, obese and older. There were no differences in baseline demographics, medications, and laboratory values between groups, except patients in RIV + ASA group had higher white blood cell counts (p=0.028) and lower baseline 2uM ADP-induced PA (p=0.03). There were no differences in other laboratory measurements between baseline and post-randomization time points within the group or at 4- and 12-week time points between groups, except D-dimer values were significantly lower at 12 weeks (p=0.038) in the RIV + ASA vs. ASA-only group. No significant adverse events were observed. Conclusions: Twelve weeks of rivaroxaban plus aspirin vs. aspirin was associated with similar levels of platelet aggregation, platelet fibrin clot strength, fibrinogen and inflammation markers, and lower d-dimer levels.