Increased Body Mass Index is Associated with Device Detected Silent Atrial Fibrillation

Introduction: Atrial fibrillation (AF) is the most common cardiac rhythm disturbance in clinical practice. To prevent adverse outcomes associated with AF, it is necessary to identify and manage the modifiable risk factors. An increased body mass index (BMI) is strongly associated with the incidence of clinically symptomatic AF. However, the association of increased BMI with asymptomatic AF is unknown. Patients and Methods: We prospectively evaluated 449 patients implanted with dual chamber pacemaker. Patients were divided into 3 groups according to their baseline BMI (normal weight: BMI 18-25 kg/m2, overweight: BMI 25-30 kg/m2, and obesity: BMI > 30 kg/m2). Six months after the device implantation, pacemakers were interrogated to identify atrial high rate episodes (AHREs), which were defined as episodes faster than 220 bpm and longer than 5 minutes. Results: AHRE was detected in 128 (28.5%) patients. Patients in the AHRE (+) group were older (65.51 ± 8.99 years vs. 70.84 ± 8.05 years, p< 0.01) and had greater BMI (26.84 ± 3.41 kg/m2 vs. 28.65 ± 3.75 kg/m2, p< 0.01) compared to those in the AHRE (-) group. Patients in the AHRE (+) group had significantly higher mean resting heart rate (84.03 ± 7.80 bpm vs. 74.76 ± 6.40 bpm, p< 0.01), greater left atrium antero-posterior (LA-AP) diameter (4.14 ± 0.33 cm vs. 3.90 ± 0.31 cm, p< 0.01), left atrium volume (31.92 ± 3.17 vs. 30.38 ± 3.15, p< 0.01), and CHA2DS2-VASc score (2.29 ± 0.83 vs. 1.81 ± 0.76, p< 0.01). On multivariate analysis, increased BMI, age, mean resting heart rate, LA-AP diameter, and CHA2DS2-VASc score were independently associated with the incidence of AHRE. Conclusion: Increased BMI is not only associated with symptomatic AF but also with asymptomatic AF detected by cardiac implantable electronic devices