Objectives To investigate the latest cutoff value of high-sensitivity cardiac troponin I for major adverse cardiac events (MACEs) during the perioperative period of coronary artery bypass grafting (CABG). Methods A total of 200 patients, into MACEs and non-MACEs groups according to the occurrence of MACEs over a 12 day postoperative period underwent a complete baseline history survey, physical examination, 12-lead electrocardiogram (ECG), and laboratory examination during a preoperative cardiology consultation. Serum levels of hs-TnI, myohemoglobin, creatine kinase MB isoform (CK-MB), and B-type natriuretic peptide were assessed using a Beckman DXI800 automatic chemiluminescence immune analyzer. Results The 200 patients were classified into the MACEs (n=10) and non-MACEs (n=190) groups. Based on a receiver-operating characteristic analysis, the optimal 4–6 h postoperative hs-TnI, CK-MB, and MYO joint cut-off levels for predicting perioperative MACEs were 2,622.3 pg/mL, 17.9 ng/mL, and 190.2 ng/mL, respectively. The AUC was 0.779 (95% confidence interval: 0.622–0.937; p<0.05) with a sensitivity of 80.0% and a specificity of 74.0%. When the hs-TnI, CK-MB, and MYO levels exceeded the joint cut-off levels, the incidence of MACEs was significantly increased during the perioperative period (Log rank p<0.05). Cox regression analysis showed that dyslipidemia, left ventricular ejection fraction <50%, hs-TnI level, and myohemoglobin level were the main risk factors for MACEs after CABG (p<0.05). Conclusion An hs-TnI level of 2,622.3 pg/mL, CK-MB level of 17.9 ng/mL, and MYO level of 190.2 ng/mL were the cutoff values for predicting MACEs. Dyslipidemia, left ventricular ejection fraction <50%, hs-TnI level, and myohemoglobin level were the main risk factors for MACEs after CABG.