Relationship between triglyceride-glucose index and coronary artery disease

Objective: Insulin resistance (IR) plays a key role in the atherosclerotic process and is known to increase the risk of coronary artery disease (CAD). The triglyceride-glucose (TyG) index has been proposed as a simple marker of IR and its association with metabolic disturbances has been demonstrated in multiple cohort studies. However, data on the relationship between the TyG index and both the presence and severity of CAD remain limited. In our study, we investigated the association of the TyG index with ST-segment elevation on ECG and angiographic lesion severity in young adults presenting to the emergency department with chest pain who were diagnosed with acute coronary syndrome (ACS) and underwent percutaneous coronary angiography (PCA). We aimed to assess the role of the TyG index in prognostication, its utility as a screening test for subclinical atherosclerosis, and its contribution to risk stratification and optimization of preventive strategies in a young ACS population. Methods: Following ethics committee approval (02.04.2025, decision no. 2025/53), this single-center, retrospective study included 208 patients under 45 years of age who presented with chest pain, were diagnosed with acute myocardial infarction, and underwent PCA. The TyG index was calculated as ln[fasting triglycerides (mg/dL) × fasting glucose (mg/dL) / 2]. Coronary lesion severity was categorized into three groups: (1) no critical lesion (<70% stenosis, no indication for percutaneous intervention), (2) single-vessel lesion (≥70% stenosis in one vessel with intervention indication), and (3) multivessel lesion (≥70% stenosis in more than one vessel with intervention indications). Results: Of the study cohort, 32 patients (19.2%) had no critical coronary lesions, 46 patients (27.5%) had single-vessel disease, and 89 patients (53.3%) had multivessel disease. A positive correlation was found between the TyG index and multivessel coronary lesion presence (AUC 0.604; 95% CI 0.522–0.681; p = 0.037), with an optimal cut-off value of 9.12 for predicting multivessel disease. Conversely, absence of critical lesions was negatively associated with the TyG index (AUC 0.681; p > 0.05), with a cut-off of 8.93. Analysis of variance showed a significant difference in TyG index across lesion-severity groups (F = 5.74; p < 0.05), with post-hoc testing revealing a significant difference between the no-lesion and multivessel groups (p < 0.05). Among patients with normal HbA1c, the TyG index also significantly differentiated lesion severity (F = 3.308; p < 0.05). Conclusion: In patients diagnosed with ACS, the TyG index is significantly associated with both the presence and extent of coronary artery lesions, emerging as a strong predictor of multivessel disease. As an inexpensive and routinely obtainable parameter, the TyG index may aid in early screening of patients with suspected ACS. Prospective studies are warranted to validate its prognostic value and explore its integration into clinical algorithms. Keywords: Triglyceride-Glucose Index; Myocardial Infarction; Emergency Medicine