OBJECTIVE:To explore the effect of dabigatran etexilate on coagulation indexes and safety of elderly patients with persistent atrial fibrillation. METHODS:52 elderly patients with persistent atrial fibrillation were randomly divided into obser-vation group and control group by random number table,26 cases in each group. Creatinine clearance rate in observation group was higher than 30 ml/min,110 mg Dabigatran etexilate capsule was orally given,bid;when 15-30 ml/min,55 mg capsule was orally given,bid. Control group orally received Warfarin sodium tablet with initial dose of 2.5 mg,qd,according to international normal-ized ratio (INR) after 3-5 days till maintained in 2.0-3.0. After 3 months,coagulation indexes [prothrombin time (PT),activated partial thromboplastin time (APTT),thrombin time (TT),INR,platelet count (PLT),fibrinogen (FIB)] before and after treat-ment,incidences of clinical events (cerebral embolism,cerebral hemorrhage,fatal bleeding,the remaining parts of embolism, death)and adverse reactions in 2 groups were compared. RESULTS:There was no significant difference in PT,APTT,TT,PLT and FIB between 2 groups before treatment(P>0.05);after treatment,PT and INR in 2 groups significantly increased,and obser-vation group was obviously better than control group,the difference was statistically significant(P<0.05). No cerebral hemorrhage or fatal hemorrhage occurred in the two groups. There was no significant difference in the incidence of cerebral embolism between 2 groups (P>0.05);the incidence of remaining parts of embolism,death in observation group significantly lower than control group,the difference was statistically significant(P<0.05). The incidence of adverse reactions in observation group was significant-ly lower than control group,the difference was statistically significant (P<0.05). CONCLUSIONS:Dabigatran etexilate shows good coagulation effect on elderly patients with persistent atrial fibrillation,which can effectively improve PT and INR levels and reduce the incidences of clinical events,with good safety.