Advanced age, history of AF, metabolic syndrome, and cardiac and renal dysfunction have been found to be potential risk factors for POAF, but the underlying mechanisms of POAF remain elusive.9 Research9 has suggested that inflammation, dysregulation of the autonomic nervous system, and overactivation of the renin-angiotensin system (RAS) system are involved in the pathogenesis of POAF. Here, REN is linked to atrial fibrillation.