Warfarin in prevention of cerebral thromboembolism in elderly patients with nonvalvular atrial fibrillation

Objective To observe the anticoagulate effect and side effect of warfarin in prevention of cerebral thromboembolism in elderly patients with nonvalvular atrial fibrillation.Methods Two hundred and sixty four patients with atrial fibrillation were randomly divided into two groups and all took different target international normalize ratio(INR)of Warfarin.In the first group(152 patients)the INR was 1.7～2.2(low intensity)and in the second group(112 patients)the INR was 2.3～3.0(moderate intensity).The incidence of cerebral thromboembolism and hemorrhage were compared.Results Two hundred and forty two patients finally finished the observation,including 139 patientsin low intensity group and 103 in moderate intensity group.The yearly incidence of cerebral thromboembolism was 2.2% and 1.9% in low intensity and moderate group,respectively(P0.05).The incidence of severe bleedingin in low intensity group was not significant different with that in moderate intensity group(0.7% vs 1.0%,P0.05).The incidence of mild hemorrhagein the moderate intensity group was higher than that in low intensity group(1.07% vs 3.6%,P0.05).Conclusions To maintain the INR at 1.7～2.2 with warfarin could safely reduce the incidence of cerebral thromboembolism in elderly patients with nonvalvular atrial fibrillation.