【Abstract】Objective To explore the appropriate dose of rivaroxaban to prevent stroke in elderly Chinese patients with non-valvular atrial fibrillation in order to improve the effectiveness and safety of anticoagulation therapy. Methods From December 2016 to December 2018,152 consecutive elderly patients with nonvalvular atrial fibrillation admitted in the First Medical Center of Chinese PLA General Hospital were randomly divided into rivaroxaban A group and rivaroxaban B group. Group A received the international recommended dose of rivaroxaban (15 mg) and group B a low dose (10 mg). After 12-month follow-up, the clinical data of 73 patients in group A and 67 patients in group B got analyzed. The blood routine, coagulation function, plasma anti-Xa factor activity concentration were tested and thromboelastography was performed before and after the treatment of rivaroxaban. The bleeding events, ischemic events and all-cause deaths were recorded during 12 months of follow-up. SPSS statistics 26.0 was used to perform the statistical analysis. Student′s t test, Chi-square test, or Rank sum test was employed for intergroup comparison depending on different data types. Kaplan-Meier survival curve is plotted for survival analysis. Results There were no significant changes in the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), serum creatinine (SCr), blood urea nitrogen (BUN), uric acid (UA) and hemoglobin (Hb), blood platelet (PLT) count, or platelet aggregation before and after rivaroxaban treatment in both groups (P>0.05). The peak activated partial thromboplastin time (APTT), peak plasma prothrombin time (PT), peak prothrombin activity (PTA), peak international normalized ratio (INR) and trough concentration of anti-Xa factor were significantly higher in group A than group B (P<0.05). But there were neither obvious differences in the other coagulation indexes between the 2 groups (P>0.05), nor in the main indicators of the thromboelastogram between them (P>0.05). Except for hematuria, no significant differences were found in the incidences of ischemic events, major hemorrhagic events and all-cause deaths between the 2 groups (P>0.05). The results of Kaplan-Meier survival analysis showed that the cumulative survival rate of group A was 93.5% and that of group B was 84.6%, but there was also no statistical difference (P>0.05). Conclusion The risk of ischemia and hemorrhage in elderly patients with non-valvular atrial fibrillation in China needs to be individually assessed before the initiatively prevention and treatment of stroke. A low dose of rivaroxaban is recommended for anticoagulation therapy, which can achieve obvious and relatively safe clinical benefits.
