Anticoagulation: risks and benefits in atrial fibrillation.

Anticoagulation with warfarin has been shown to be effective in preventing ischemic stroke in patients with atrial fibrillation. However, physicians have been reluctant to prescribe this therapy for patients age 60 and older because of the associated risk of bleeding during antithrombotic therapy. Four clinical features independently increase the risk of stroke in individuals with atrial fibrillation: previous stroke or transient ischemic attack, diabetes, history of hypertension, and advancing age. In individual patients, bleeding complications can be reduced by eliminating loading doses, monitoring therapy frequently during the initiation phase, targeting lower INRs, recognizing the potential for drug interactions, and identifying clinical risk factors.