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Invited Commentary
Apr 23, 2012

A New Era in Stroke Prevention for Atrial Fibrillation: Comment on “Current Trial-Associated Outcomes With Warfarin in Prevention of Stroke in Patients With Nonvalvular Atrial Fibrillation

Author Affiliations

Author Affiliations: Clinical Epidemiology Unit, Division of General Medicine, Massachusetts General Hospital, Boston (Dr Singer); and Division of Research, Kaiser Permanente Northern California, Oakland (Dr Go).

Arch Intern Med. 2012;172(8):631-633. doi:10.1001/archinternmed.2012.897

The article by Agarwal et al1 summarizing the performance of warfarin in recent trials of stroke prevention in atrial fibrillation (AF) in this issue of the Archives provides an opportunity to review the growing set of novel anticoagulation alternatives for patients with AF and the remaining role for warfarin.

Atrial fibrillation, the most common significant cardiac arrhythmia, raises the risk of ischemic stroke 5-fold. Dose-adjusted warfarin therapy reduces this risk by two-thirds.2 However, warfarin therapy is burdensome and risky, and its effect varies as a result of food and drug interactions and genetic differences.3 The safe management of warfarin therapy demands frequent international normalized ratio (INR) testing and dose adjustment as well as ongoing patient education regarding common hazards. The risks of ischemic stroke and intracranial hemorrhage are minimized at INR values of 1.8 to 3.5.4 Beyond this range, the risks increase steeply.