Tenascin-C differentiates obstructive from non-obstructive coronary artery disease in non-ST-elevation acute coronary syndrome.

BACKGROUND: Differentiating obstructive from non-obstructive coronary artery disease (CAD) at the time of acute coronary syndrome (ACS) diagnosis remains challenging, and there is a need for biomarkers that can provide clearer discrimination. AIM: This study aims to assess Tenascin-C's diagnostic utility in predicting significant coronary artery stenosis in individuals with ACS. METHOD: In this prospective single-center observational study, 204 patients with NSTEMI or UAP who underwent invasive coronary angiography were included. Serum Tenascin-C levels were measured within 48 h using ELISA, and patients were classified as having critical (≥70%) or non-critical CAD based on blinded angiographic assessment. The relationship between Tenascin-C, critical stenosis, and GRACE and SYNTAX scores was evaluated using logistic regression, correlation analyses, and ROC curves. RESULTS: Tenascin-C levels demonstrated robust discriminative performance (AUC 0.85) and were considerably greater in patients with critical CAD among the 204 included patients. Tenascin-C was the sole independent predictor of critical stenosis in multivariate analysis. Tenascin-C showed a modest correlation with the GRACE score and a substantial correlation with the SYNTAX score. Tenascin-C maintained a good diagnostic accuracy (AUC 0.87) in individuals with borderline hs-TnT levels (12-52 ng/L). CONCLUSION: Tenascin-C demonstrated greater discriminative ability than hs-TnT for identifying critical coronary stenosis in patients with NSTEMI or UAP, particularly in the borderline troponin range. These findings suggest that Tenascin-C may provide complementary information to current biomarkers and support more precise clinical decision-making.