Variations in Etiology and Management of Atrial Fibrillation in a Prospective Registry of 15,400 Emergency Department Patients in 46 Countries: The RE-LY AF Registry

Study Questions:

How does the presentation and management of patients with atrial fibrillation (AF) differ in various parts of the world?


A prospective registry enrolled 15,400 patients presenting to the emergency department with AF in 46 nations. Clinical data were collected through patient interviews and review of the medical record.


The average age was 65.9 ± 14.8 years, with patients in India, Middle East, and Africa being 10-12 years younger than those in the Americas, Europe, and China. Hypertension was present in 62% of patients overall, with the highest prevalence in Eastern Europe (81%), and lowest in India (42%). The average CHADS2 score was 1.8 ± 1.4, with the highest score in Eastern Europe (2.3 ± 1.2) and lowest in India (1.1 ± 1.1). Rheumatic heart disease (RHD) was present in 12% of the registry patients, and varied substantially across regions: 1.5% in Western Europe and 32% in India. The highest prevalence of obesity was found in North America (15%) and the lowest in Asia (0.6-2.2%). Among patients with a CHADS2 score ≥2, but without RHD, 45% of all patients were taking an oral anticoagulant at presentation, as compared to only 11-25% of patients in China, Africa, and India. The mean time in therapeutic range was highest in Western Europe (62%) and lowest in Asia and Africa (32-40%).


The authors concluded that there is a large global variation in age, contributing risk factors, and treatment of AF between regions.


The global variation in the presentation and management of patients with AF can largely be explained by the prevalence of recognized risk factors (e.g., hypertension, RHD, and obesity) and the disparity in resources. Given that the latter cannot be addressed easily, the most cost-effective method to combat AF is, of course, prevention. While treatment and prevention of hypertension and obesity are potentially feasible, prevention of RHD is more problematic. Access to medical treatment, and the fact that acute rheumatic fever may result from clinically inapparent infection, contribute to the high prevalence of RHD in the developing world. A vaccine may have profound implications on the morbidity associated with Streptococcal infections, but has thus far remained elusive.

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