Abstract
The triglyceride-glucose (TyG) index is a surrogate marker of insulin resistance (IR) asso-ciated with atherosclerosis, endothelial dysfunction, and cardiovascular disease (CVD). Chronic total occlusion (CTO) presents major clinical challenges, especially in patients undergoing percutaneous coronary intervention (PCI). This narrative review explores the role of the TyG index in predicting CTO development and adverse cardiovascu-lar outcomes. A literature review of studies assessing the association between the TyG index and CTO, PCI outcomes, and contrast-induced nephropathy (CIN) was conducted. Pathophysiological mechanisms linking IR, TyG, and CTO progression were evaluated, and the predictive utility of the TyG index in risk stratification and post-PCI complica-tions was analyzed. Multiple studies show that a higher TyG index is strongly associated with increased CTO risk, poor collateral circulation, CIN, and adverse outcomes after PCI. Elevated TyG values were independently predictive of impaired collateral formation in diabetic and non-diabetic patients, with stronger effects in metabolically vulnerable subgroups. Individuals with higher TyG levels had a greater likelihood of developing CIN, with analyses confirming its role as an independent predictor. Long-term prognosis in CTO patients was also worse with elevated TyG, with higher rates of major adverse car-diovascular events. The TyG index demonstrated consistent predictive capability com-pared with other metabolic markers, supporting its potential as a low-cost tool for risk stratification. The TyG index is a cost-effective biomarker for predicting adverse out-comes in CTO patients. Its incorporation into clinical assessment may improve early risk identification and support individualized PCI planning.