Diagnostic Value of Copeptin and Growth Differentiation Factor-15 for Sepsis-Related Myocardial Injury

Biomarkers play a critical role in the diagnosis and clinical decision-making for sepsis-related myocardial injury (SMI). SMI has no single accepted definition. Copeptin and growth differentiation factor-15 (GDF-15), which are associated with stress response and systemic inflammation, have emerged as potential diagnostic markers. This study aimed to investigate the expression levels of copeptin and GDF-15 in SMI patients and evaluate their diagnostic utility.

This case-control study enrolled 148 sepsis patients admitted to the emergency department and 43 healthy controls. Patients with sepsis were divided into the SMI group and the non-SMI group. SMI was defined as cTnT >40.0 pg/mL and/or LVEF <50% in patients with sepsis, after excluding clear alternative causes of myocardial injury. Blood samples were collected within 48 hours after admission, and serum copeptin and GDF-15 levels were measured and compared with clinical indicators. Univariate and multivariate logistic regression analyses were performed to identify factors associated with SMI. The diagnostic performance of copeptin and GDF-15 was evaluated using receiver operating characteristic (ROC) curve analysis.

Copeptin and GDF-15 levels were significantly elevated in SMI patients compared to both sepsis patients without myocardial injury and healthy controls (P < 0.01). Multivariate analysis confirmed that copeptin (OR 1.018, 95% CI: 1.001-1.035) and GDF-15 (OR 1.266, 95% CI: 1.102-1.454) were independently associated with SMI. ROC analysis demonstrated diagnostic performance for SMI, with an AUC of 0.884 (95% CI: 0.837-0.931) for copeptin and 0.862 (95% CI: 0.810-0.914) for GDF-15. The combined use of both biomarkers further improved diagnostic accuracy (AUC = 0.911, 95% CI: 0.871-0.951).

Serum copeptin and GDF-15 levels were elevated in patients with SMI and may provide complementary value for identifying myocardial injury in patients with sepsis, with enhanced diagnostic capability when used in combination. Further validation in larger multicenter studies is needed before these biomarkers can be used in routine clinical practice.