There is evidence on the role of the phosphotransfer system in the energy metabolism of the heart, with altered energetics playing an important role in the mechanisms of heart failure. Phosphocreatine plays an important part in the energy heart system. The investigators have just performed a systematic review and meta-analysis of randomized controlled trials (RCTs) and matched studies that compared phosphocreatine with placebo or standard treatment in patients with coronary artery disease or chronic heart failure or in those undergoing cardiac surgery. Patients receiving phosphocreatine had lower all-cause mortality as well as improved cardiac outcomes when compared to the control group, however, the quality of the included studies was low. Thus, the investigators plan to conduct an exploratory high quality RCT to investigate whether providing phosphocreatine compared to placebo improves the myocardial protection in high-risk patients scheduled for cardiac surgery and to determine the best research endpoint for future trials.