Coronary heart disease ranks first as the leading cause of death in the world, an estimated 17.9 million people die every year. Coronary artery bypass surgery (CABG) is one of the management interventions for CHD patients, but the high mortality rate after CABG and other risks is still high. The STS score is one of two types of scores currently used to predict the incidence of mortality in patients undergoing cardiac surgery. Objective: To determine the role of STS scores in predicting Major Adverse Cardiovascular Events (MACE) in patients undergone coronary artery bypass surgery during admission in Haji Adam Malik General Hospital Medan. Methods: This study is a retrospective cohort study of 75 CHD patients who undergone CABG at Haji Adam Malik Hospital Medan from June 2019 to June 2020. Each patient who undergone CABG was calculated using the STS calculator to assess the risk of post-CABG outcome. There are nine risks that are assessed and then the relationship will be assessed with the incidence of MACE in CABG patients. Statistical analysis was performed to assess the role of the STS outcome score in predicting MACE. Results: From 75 patients undergoing CABG, 12 patients (16.0%) experienced major cardiovascular events (MACE). Acute heart failure was the highest MACE during hospitalization, around 33,3%. The STS risk score for prolonged ventilation and risk of major morbidity/mortality were predictor factors that were statistically significant, respectively with OR 0.061 and p value = 0037; and OR 5.667 and p value = 0.017, with constant being -36.794. The ROC analysis obtained a cutoff point of the STS score for the risk of prolonged ventilation against the incidence of MACE, namely at a score of 6,36% (AUC:0,868; sens 83,3%; spes 81,0%;p<0,001) and the cut-off point STS score for the risk of major morbidity/mortality to the incidence of MACE at a score of 10.355% (AUC: 0,852; sens 83,3%; spes;74,6%; p<0,001). Conclusion: STS score can be used as predictor of MACE in patients undergoing coronary artery bypass surgery.

Keywords : STS score, MACE, CABG