ObjectiveTo investigate the predictive value of a new nutritional index, triglycerides-total cholesterol-body mass index (TCBI), for prolonged postoperative hospital stay in patients undergoing coronary artery bypass grafting surgery (CABG). MethodsA retrospective analysis was conducted on the clinical data of CABG patients admitted to Wuhan Asian Heart Hospital, Wuhan University of Science and Technology from January 2022 to March 2024. Based on the postoperative hospital stay duration of CABG patients, they were divided into two groups: normal hospital stay group (≤14 days) and prolonged hospital stay group (>14 days). Univariate and multivariate logistic regression analyses were used to identify independent factors associated with prolonged postoperative hospital stay in CABG patients. The receiver operating characteristic (ROC) curve was employed to evaluate the predictive value of TCBI for prolonged postoperative hospital stay. ResultsA total of 460 patients were included, with 289 males (62.8%) and 171 females (37.2%), with an average age of 67 years (range 35-83 years). The TCBI level in the prolonged hospital stay group was significantly lower than that in the normal hospital stay group [1161.71 (825.36, 1511.78) vs. 1777.60 (1354.53, 2448.60), P<0.001]. Multivariate logistic regression analysis revealed that drinking history (OR=2.222, P=0.022), low absolute lymphocyte count (OR=0.169, P<0.001), low serum albumin (OR=0.624, P<0.001), and low TCBI (OR=0.816, P<0.001) were independent risk factors for prolonged postoperative hospital stay in CABG patients. ROC curve results showed that the area under the curve for TCBI to predict prolonged hospital stay was 0.808, with a sensitivity of 72.8% and specificity of 70.9% at a cutoff value of 1446.11. ConclusionTCBI is an effective predictive indicator for prolonged postoperative hospital stay in CABG patients, and the risk of prolonged postoperative hospital stay is higher in CABG patients with TCBI ≤1446.11.