Four weeks after Exo treatment, venous blood samples were collected for ELISA to detect myocardial injury related indicators (BNP, CK-MB, cTnI and TNF-a), qRT-PCR and Western Blot to detect the expression level of key gene Smad3, HE staining and Masson staining to evaluate the degree of myocardial fibrosis. This evidence concerns the gene NPPB and Myocardial fibrosis.