Wang Q, et al. - Researchers assessed the predictive value of Activin A expression in epicardial adipose tissue (EAT) on postoperative atrial fibrillation (AF) (POAF) in 89 patients receiving cardiac surgery with no history of AF, with 49 patients with valvular heart disease (VHD) and 40 patients with non-valvular heart disease (NVHD). Using quantitative polymerase chain reaction (qPCR), the expression of Activin A in EAT was determined. They performed echocardiography to determine the thickness of EAT (EATT). They also documented any new onset POAF before discharge. In this study, Activin A expression in EAT was identified as an independent risk factor for POAF. Also, Activin A expression enabled prediction of the occurrence of POAF with a sensitivity of 65.6% and specificity of 91.2%, and so, can be used for predicting POAF, especially in patients with VHD.