The statistics are stark: AFib increases the risk of ischemic stroke 5-fold in some series; it accounts for ≥15% of all strokes, 36% of strokes for individuals aged >80, and in up to 20% of cryptogenic strokes [9] [2] [10] [11] [12] More important, strokes in patients with AFib tend to be larger, more disabling, more likely to recur or be fatal, and more likely to prolong hospitalization; these patients may also present dementia.  In addition, strokes in patients with AFib result in greater healthcare costs compared to strokes in patients without AFib.  Most important, there are >100,000 embolic strokes per year as a result of AFib, with over 20,000 deaths – and these outcomes should be preventable with effective use of anticoagulation. 

Reiffel JA. Am J Med 2013; 126: 00-00.