This project explores the role and mechanism of ulinastatin in preventing cardiac dysfunction caused by cardiopulmonary bypass by reducing cardiac endothelial permeability through clinical research. Our previous basic research has found that inhibiting the TK/B1R/ARNT/MMP3/iNOS signaling axis in the acute phase of cardiac R/I can reduce the permeability of cardiac endothelial cells, reduce cardiac edema and improve cardiac function (this part has been completed) . This study intends to investigate the effects of ulinastatin on 24-hour cardiac function and prognosis in patients undergoing cardiac surgery undergoing cardiopulmonary bypass (cardiac function, inflammatory indicators, coagulation function, capillary leakage indicators, 28-day survival time, CCU time). At the same time, we observed the dynamic changes of TK/B1R/MMP3 during cardiopulmonary bypass in patients undergoing cardiac surgery and explored its relationship with prognosis, as well as the effect of ulinastatin intervention on TK/B1R/MMP3 before and after cardiopulmonary bypass.