To preliminarily explore the role of SIRT1 in left atrial remodeling and myocardial fibrosis, this experiment aimed to establish a mitral regurgitation (MR) model in miniature pigs and carried out long-term observations on the regulatory role of SIRT1 in mitral regurgitation-induced left atrial fibrosis. This evidence concerns the gene SIRT1 and Myocardial fibrosis.