Current guidelines recommend standard warfarin anticoagulation international normalized ratio (INR) goal of 2.0-3.0 in adults with non valvular atrial fibrillation (NVAF). The investigators hypothesized that low-intensity warfarin (INR 1.5-2.0) has the same effectiveness and better security in elderly patients (>75) with NVAF.
Atrial fibrillation is the commonest chronic arrhythmia in clinical practice, especially in octogenarians. Nonvalvular atrial fibrillation increases the risk of ischemic stroke by approximately 5-fold and these strokes result in higher mortality and disability. Warfarin is recommended as first line anticoagulation treatment in patients with NVAF who are at moderate or high risk of stroke,while antiplatelet agents, such as aspirin, give a more convenient but less effective alternative in the prevention of ischemic stroke and are recommended in low risk patients.Current guideline about warfarin anticoagulation therapy recommend that target INR value must be maintained between 2.0 and 3.0,which not only reduces the frequency of ischaemic stroke but also its low incidence of major bleeding. However, the current status of anticoagulation therapy for elderly Chinese AF patients, particularly in aged over 80 years, is not clear. The purpose of the present study was to test the hypothesis that an INR target of 1.5-2.0 can provide the same efficacy and better safety as compare with a standard target of 2.0-3.0 in patients over 75 with NVAF.
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