In the Department of Cardiovascular Surgery, we are mainly conducting clinical research aimed at improving the results of cardiovascular surgery. In general, in the field of cardiovascular surgery, the target cases are often high-risk, so we are focusing on the development of surgical methods and research on pre-, intra-, and post-operative management. The target diseases are divided into ischemic heart disease, valvular disease, aortic disease, and congenital heart disease, and the range is wide because independent studies have been conducted for each. In addition, researches on artificial organs such as heart-lung machines are being conducted, leading to improvements in their performance and results. We are also planning heart transplantation and large-scale clinical trials in collaboration with other facilities. Currently, we are conducting researches on the following contents. (1) Study on the correlation between postoperative acute renal dysfunction and biomarkers in cardiac surgery cases. (2) Elucidation of factors that affect the recovery of physical function after cardiac surgery. (3) Research on improving the prognosis of life in coronary artery bypass grafting. (4) Research related to heart-lung machine and extracorporeal circulation.