Clinical Study of Warfarin for Thromboembolism Prevention in the Elderly with Nonvalvular Atrial Fibrillation

Objective To investigate the efficacies and complications of warfarin for preventing thromboembolism associated with nonvalvular atrial fibrillation in older patients.Methods 151 older patients were enrolled with nonvalvular atrial fibrillation(aged from 60~75 years) during June 2005 to June 2007.They were randomly divided into warfarin group(n=76 warfarin incipient dosage 2.5 mg per day) and aspirin group(n=75 aspirin 300 mg per day),and all patients routine treatment were given.The patients in warfarin group were monitored international norma1ized ratio(INR) carefully and 1NR was controlled in 1.5~2.0.A1l patients were followed up 2 years in outpatient department or in the form of a telephone survey.The rate of ischemic stroke and complication were observed.Results 134 patients accom1ished the follow up,including 69 patients in warfarin group and 65 in aspirin group.11.2% patients did not finish the fol1ow up.During the 2 years follow up,the incidence of ischemic strokes was 2.8% in warfarin group and 7.8% in aspirin group(P0.05).Subcutaneous hemorrhage complications occurred in 3 patients in warfarin group.Large gastrointestinal hemorrhage occurred in 1 patient in aspirin group.The rate of complications was low in both groups(7.2% in warfarin group and 9.2% in aspirin group) and did not differ significantly(P0.05).Warfarin dosage targeted at 1.25～2.5mg per day.Conclusions Warfarin(INR 1.5~2.0) seems to be more effective and safe than aspirin in the prevention of throboembolism in older individuals with nonvalvular atrial fibrillation.