Overweight and obesity in patients with atrial fibrillation: Sex differences in 1-year outcomes in the EORP-AF General Pilot Registry

Background: The impact of overweight and obesity on outcomes in "real world" patients with atrial fibrillation (AF) is not fully defined. Second, sex differences in AF outcomes may also exist. Methods and results: The aim was to investigate outcomes at 1 year follow-up for AF patients enrolled in the EORP-AF Registry, according to BMI (kg/m(2)), comparing patients with normal BMI (18.5 to < 25 kg/m(2)), overweight (25 to < 30 kg/m(2)) and obesity (30 kg/m(2)), in relation to sex differences. Among 2,540 EORP AF patients (38.9% female; median age 69) with 1 year follow-up data available, 720 (28.3%) had a normal BMI, 1,084 (42.7%) were overweight, and 736 (29.0%) were obese. Obese patients were younger and with more prevalent diabetes mellitus and hypertension (P < 0.001). One-year outcomes showed that all-cause mortality was significantly different according to BMI among female patients (9.3% normal BMI, 5.3% overweight, and 4.3 % obese, P = 0.023), but not among male patients (P = 0.748). The composite outcome of thromboembolic events and death was also significantly different, being lower in obese females (P = 0.035). Among male patients, bleeding events were significantly more frequent in obese subjects (P = 0.035). On multivariable Cox analysis, BMI was not independently associated with all-cause mortality. Conclusions: Among AF patients, overweight and obesity are common and associated with better outcomes in females (a finding previously reported as "obesity paradox"), while no significant differences in outcomes are detected among male patients. Final multivariable model found that increasing BMI was not associated with increased risk of all-cause death; conversely, age and comorbidities persisted as major determinants.