The Impact of Obesity on Early Post-Operative Atrial Fibrillation Burden

Abstract Background Obesity has been linked to development of post-operative atrial fibrillation (PoAF). This study is aimed at investigating the role of BMI in the evolution of de-novo, early PoAF by assessing differences between obese and non-obese patients undergoing cardiac surgery. Methods Patients with early de-novo PoAF were included. Continuous cardiac rhythms were recorded during the first 5 post-operative days in obese (N=67, 66 ± 9 years; 51 (76%) male) and non-obese (N=89, 69 ± 9; 75 (84%) male) patients without an AF history undergoing cardiac surgery. PoAF burden was defined as the ratio between total duration of all AF episodes and total recording time ( AFB(%)). Results A total of 1191 (median: 5/patient) PoAF episodes were identified in the obese group compared to 1218 (median: 4/patient) in the non-obese group. The median duration and number of prolonged (>60 minutes) PoAF episodes was higher in obese patients (250 versus 145 minutes, p=0.003 and median of 2 versus 1 episode, p=0.031). Obesity was associated with a larger early PoAF burden (obese patients: median 7%; IQR: 2.5-19.7% versus non-obese patients: median 3.2%; IQR: 0.5-8.8%, p=0.001) mainly on the third post-operative day (p=0.021). Conclusion Obesity predisposes to a larger number of prolonged AF episodes in the early, post-operative period after cardiac surgery for coronary artery disease and/or valvular heart disease. The higher AF burden in the early post-operative period occurred particularly on the third day. Future studies will determine whether obesity prevention may play a key role in reducing the incidence of PoAF in patients undergoing cardiac surgery.