Association of Triglyceride-Glucose Index with the Severity (Assessed by SYNTAX Score) of Coronary Artery Disease in Patients with Acute Coronary Syndrome

Background: Acute Coronary Syndrome (ACS) is a significant manifestation of coronary artery disease (CAD). Severity of CAD is determined by SYNTAX score based on coronary angiogram which is an invasive procedure. A noninvasive evaluation of CAD severity by Triglyceride-Glucose (TyG) index before coronary angiogram might help with risk assessment and selection of treatment strategy. Objective: To evaluate the association of Triglyceride-Glucose (TyG) index with severity of CAD determined by SYNTAX score in patients with ACS. Methods: This cross-sectional study was done in the department of Biochemistry of Sir Salimullah Medical College from March 2024 to February 2025. A total 224 patients with ACS undergoing coronary angiography were enrolled as study subjects by purposive sampling. TyG index was calculated from fasting plasma glucose and fasting serum triglycerides level. Subjects were grouped according to the tertile of TyG index into tertile 1 (T1), tertile 2 (T2) & tertile 3 (T3). A SYNTAX score of ≤22 was considered as not severe and a SYNTAX score of > 22 was considered as severe CAD. Severity of CAD was compared among different tertile groups by chi square test. Association of high TyG Index with severity of CAD was determined by odds ratio (OR). The correlation of TyG Index with severity of CAD was determined by Pearson’s correlation coefficient test. The cut off point of TyG index was determined by Youden’s Index. The diagnostic role of TyG index for detection of severe CAD was determined by Receiver operator characteristic (ROC) curve, the area under (AUC) curve, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy. P-value ≤0.05 was considered statistically significant. Results: Among 224 subjects divided into TyG index tertiles, the highest tertile (T3) was strongly associated with a high SYNTAX score (>22), and subjects with high TyG index (>8.47) found to have 37.83 times more risk to have severe CAD (OR= 37.83, CI:17.06-84.0). The TyG index showed a significant positive correlation with the SYNTAX score (r=0.880, p< 0.001). Receiver operating characteristics (ROC) curve analysis of TyG index (cut-off point 8.47) for predicting severe CAD showed the area under curve (AUC) to be 0.99, sensitivity 76.5%, specificity 92.0%, PPV 88.0%, NPV 83.5% and accuracy 85.0%. Conclusion: High TyG index was associated with increased severity of coronary artery disease in ACS patients. High TyG index was a good predictor of severe CAD with high sensitivity , specificity, diagnostic accuracy and AUC. Bangladesh Medical Res Counc Bull 2025;51(3): 145-150