Our results suggest that cardiac telocytes, novel cardiac interstitial cells, play a potent role in promoting the survival and inhibiting the apoptosis of cardiac endothelial cells (especially CMECs) under MI via CT exosomal miRNA-21-5p-targeted Cdip1 silencing to downregulate caspase-3 activity and facilitate cardiac angiogenesis to improve the regeneration of MI. Here, CASP3 is linked to myocardial infarction.