Occurrence of death and stroke in patients in 47 countries 1 year after presenting with atrial fibrillation: a cohort study

Summary Background Atrial fibrillation is an important cause of morbidity and mortality worldwide, but scant data are available for long-term outcomes in individuals outside North America or Europe, especially in primary care settings. Methods We did a cohort study using a prospective registry of patients in 47 countries who presented to a hospital emergency department with atrial fibrillation or atrial flutter as a primary or secondary diagnosis. 15 400 individuals were enrolled to determine the occurrence of death and strokes (the primary outcomes) in this cohort over eight geographical regions (North America, western Europe, and Australia; South America; eastern Europe; the Middle East and Mediterranean crescent; sub-Saharan Africa; India; China; and southeast Asia) 1 year after attending the emergency department. Patients from North America, western Europe, and Australia were used as the reference population, and compared with patients from the other seven regions Findings Between Dec 24, 2007, and Oct 21, 2011, we enrolled 15 400 individuals to the registry. Follow-up was complete for 15 361 (99·7%), of whom 1758 (11%) died within 1 year. Fewer deaths occurred among patients presenting to the emergency department with a primary diagnosis of atrial fibrillation compared with patients who had atrial fibrillation as a secondary diagnosis (377 [6%] of 6825 patients vs 1381 [16%] of 8536, p Interpretation Marked unexplained inter-regional variations in the occurrence of stroke and mortality suggest that factors other than clinical variables might be important. Prevention of death from heart failure should be a major priority in the treatment of atrial fibrillation. Funding Boehringer Ingelheim.