Stroke As The Initial Manifestation Of Atrial Fibrillation: The Framingham Heart Study

Background and Purpose-To prevent strokes that may occur as the first manifestation of atrial fibrillation (AF), screening programs have been proposed to identify patients with undiagnosed AF who may be eligible for treatment with anticoagulation. However, the frequency with which patients with AF present with stroke as the initial manifestation of the arrhythmia is unknown.Methods-We estimated the frequency with which AF may present as a stroke in 1809 community-based Framingham Heart Study participants with first-detected AF and without previous strokes, by tabulating the frequencies of strokes occurring on the same day, within 30 days before, 90 days before, and 365 days before first-detected AF. Using previously reported AF incidence rates, we estimated the incidence of strokes that may represent the initial manifestation of AF.Results-We observed 87 strokes that occurred 1 year before AF detection, corresponding to 1.7% on the same day, 3.4% within 30 days before, 3.7% within 90 days before, and 4.8% 1 year before AF detection. We estimated that strokes may present as the initial manifestation of AF at a rate of 2 to 5 per 10000 person-years, in both men and women.Conclusions-We observed that stroke is an uncommon but measureable presenting feature of AF. Our data imply that emphasizing cost-effectiveness of population-wide AF-screening efforts will be important given the relative infrequency with which stroke represents the initial manifestation of AF.