In summary, our study determined that the occurrence of postoperative AF in patients who have no previous history of AF was correlated with atrial fibrosis and that the MAPKs/TGF-β1/TRAF6 signaling pathway was altered in these patients, which suggests that this pathway is an important signaling pathway in the CTGF expression induced by AngII. This evidence concerns the gene AGT and atrial fibrillation.