Low-intensity anticoagulation for stroke prevention in elderly patients with atrial fibrillation: efficacy and safety in actual clinical practice.

Low-intensity warfarin (INR 1.5 to 2.5) was started in 63 patients with atrial fibrillation (AF) and they were prospectively followed for 2.3 +/- 1.4 years to determine the efficacy and safety of anticoagulation for stroke prevention in actual clinical practice. Although the patients in this practice were older (76 +/- 7 years), consisted of more women (52%), and had more risk factors for stroke compared with those in clinical trials, the annual event rates of stroke and systemic embolism in this practice were comparable to those of patients receiving warfarin in clinical trials (2.0% vs. 1.4% and 0.7% vs. 0.3%). The rate of major bleeding did not significantly differ between this practice and clinical trials (0.7% vs. 1.3%). The rate of minor bleeding was significantly lower in this practice than in clinical trials (3.4% vs. 7.9%). The data suggest that low-intensity anticoagulation is effective and safe for stroke prevention in elderly patients with AF at stroke risk in actual clinical practice.