This project aims to explore the metabolic characteristics of adverse renal outcomes in high-risk populations after cardiac surgery by using multi-omics techniques, in order to understand the metabolic changes in patients during the process of renal function decline and recovery. At the same time, this project will search for combinations of metabolic markers that predict the occurrence of adverse outcomes, establish predictive models, to help clinical early identification and warning of AKI, and implement prevention and intervention strategies, thereby improving the prognosis of patients and enhancing the safety and success rate of cardiac surgery.