Rivaroxaban Plasma Concentration and Clinical Outcomes on Older Patients with Non-valvular Atrial Fibrillation and Pulmonary Infection.

Introduction: Infection may induce thrombotic and hemorrhagic events; however, it is currently unclear whether the inflammatory response affects the coagulation function and the clinical efficacy and safety of rivaroxaban in older patients with non-valvular atrial fibrillation (NVAF). Objective: This project aimed to assess the effectiveness and safety of the non-vitamin K antagonist oral anticoagulant rivaroxaban in older patients with NVAF complicated by infection, and to provide a basis for possible drug dose adjustment. Methods: A total of 152 NVAF patients aged ≥ 65 years admitted to the Fifth People's Hospital of Shanghai from June 2020 to May 2022 were included in this prospective, observational study. The changes in steady-state plasma concentration of rivaroxaban and FXa inhibition rate were compared between patients with and without infection, and the impact on the occurrence of infection, thrombotic events, and bleeding events was compared through 1-year follow-up. Results: Our results showed that patients in the infection group had abnormal inflammation markers, as well as an increased occurrence of bleeding and thrombotic events during hospitalization and follow-up. The high incidence of bleeding events in patients was closely related to the occurrence of infection, lymphocyte reduction, and increased neutrophil-lymphocyte ratio. The increase in thrombotic events was related to a decrease in rivaroxaban plasma concentration. Bleeding events in patients taking anticoagulant drugs are not necessarily due to drug accumulation. Conclusions: Timely control of infection, assessment of bleeding and thrombotic risks, and selection of appropriate anticoagulation treatment strategies should be made in older NVAF patients who develop pulmonary infection. Clinical Trials Registration: Chinese Clinical Trial Registry Number ChiCTR2000033144. [ABSTRACT FROM AUTHOR]