Abstract
INTRODUCTION: Traumatic Brain Injury (TBI)-induced secondary myocardial injury (SMI) is a severe complication with poor prognosis, but reliable early predictive tools are lacking. This study aimed to develop and validate a nomogram for predicting this risk in TBI patients admitted to the intensive care unit (ICU). METHODS: We retrospectively analyzed 1,042 ICU-admitted TBI patients without pre-existing cardiac disease from the MIMIC-IV database, randomly divided into training (n = 729) and internal validation (n = 313) sets at a 7:3 ratio. An external validation cohort of 200 patients from Zhejiang Provincial People's Hospital (2020-2025) was also included. Five key predictors were identified via univariate and multivariate logistic regression. RESULTS: The final model included blood urea nitrogen, hemoglobin, Sequential Organ Failure Assessment (SOFA) score, serum potassium, and creatinine. It showed good discriminative ability: training set AUC = 0.772 (95%CI: 0.737-0.808), internal validation set AUC = 0.785 (95%CI: 0.733-0.837), and external validation set AUC = 0.848 (95%CI: 0.778-0.917). CONCLUSIONS AND DISCUSSION: This nomogram, based on easily accessible clinical parameters, enables early risk stratification of SMI in TBI patients before cardiac biomarker elevation, providing a practical tool for targeted clinical monitoring and intervention.