RESUMO
Objective To assess the effectiveness and security of warfarin in the treatment of anticoagulation in elderly patients with chronic atrial fibrillation.Methods The patients of chronic atrial fibrillation were divided into two groups randomly warfarin group (group A) and aspirine group (group B). PT and INR of the whole patients were detected, the group A were administed 3 mg/d dose of warfarin. PT and INR were detected every other day. One week later, the dosage of warfarin was increased to 4 mg/d if INR did not reach 2.0-3.0. INR was detected every other week until it reached about 2.0-3.0. Four weeks later, INR was detected every month.. When the patients were inclined to hemorrhagia symptom, their INR was detected immediately. The patients group B were administered aspirin 300 mg orally twice a day . Results In group A, PT was significantly lower than that before treatment, P