Objective  To study the effect of warfarin anticoagulation therapy in different intensity on prognosis and long-term efficacy in elderly patients with non-valvular atrial fibrillation.

  Methods  A total of 90 elderly patients with non-valvular atrial fibrillation admitted to our hospital were divided into low intensity group, standard intensity group and aspirin treatment group according to the intensity of warfarin anticoagulation therapy, with 30 cases in each group. International standardized ratio(INR) of low intensity group was 1.6~2.0, and 2.1~3.0 in standard intensity group. After 3, 6, 12, and 24 months of treatment, the improvement of renal function and the occurrence of thromboembolism, hemorrhage, and endpoint events were compared between the three groups.

  Results  There was no significant difference in creatinine clearance (Ccr) among the three groups after 3 months of treatment compared with before treatment (P>0.05). Ccr levels of of the three groups were improved after 3-month treatment(P < 0.05). After 6, 12 and 24 months of treatment, the Ccr levels of the low intensity group and the standard intensity group were significantly higher(P < 0.05), and was decreased in aspirin group compared with treatment before(P < 0.05), and significant differences were observed in low intensity group, and standard intensity group(P < 0.05). After treatment, the incidence of thromboembolism of the low intensity group and standard intensity group was significantly lower than that of aspirin group (P < 0.05). The incidence of endpoint events in low intensity group was significantly lower than that in aspirin group (P < 0.05), while there was no significant difference between standard intensity group and aspirin group (P>0.05).

  Conclusion  Low-intensity warfarin anticoagulation therapy can significantly improve renal function, reduce the incidence of bleeding and improve the safety of medication in the treatment of elderly patients with non-valvular atrial fibrillation.