Exploring The Obesity Paradox In Atrial Fibrillation. AFBAR (Atrial Fibrillation Barbanza Area) Registry Results.

ABSTRACT

INTRODUCTION AND OBJECTIVES: Previous studies have described an inverse relationship between obesity and adverse events in a variety of conditions. Our aim was to investigate the relationship between obesity and prognosis in patients with atrial fibrillation. METHODS: We studied 746 patients who were prospectively included, between January and April 2008, in the AFBAR (Atrial Fibrillation in BARbanza area) registry. Patients were categorized into 3 body mass index groups using baseline measurements normal (< 25 kg/m2), overweight (25-30 kg/m2), and obese (≥30 kg/m2). Survival free from the composite endpoint hospitalization for cardiovascular causes or all-cause mortality was compared across the 3 body mass index groups. A multivariable Cox proportional hazard regression was also performed to determine the independent effect of obesity as well as overweight, with respect to normal body mass index as a reference category, regarding the study endpoint. Median follow-up time was 36 (28-36) months. RESULTS: 49.3% were obese and 38.2% had overweight. The composite endpoint rate was 70.9%, 67.5%, and 57.6% for obese, overweight, and normal weight patients, respectively (log rank test; p=0.02). An inverse association of obesity with a favorable prognosis persisted even after multivariable adjustment hazard ratio 0.668; 95% confidence interval 0.449-0.995; p=0.047. Hazard ratio of overweight, however, was 0.741; 95% confidence interval 0.500-1.098; p=0.096. CONCLUSIONS: Obesity, defined as a body mass index ≥ 30 kg/m2, is associated with better prognosis in a community-based cohort of patients with atrial fibrillation.