Prognostic markers in pediatric dilated cardiomyopathy: Focus on the neutrophil‑to‑lymphocyte ratio and the systemic inflammatory index

Dilated cardiomyopathy (DCM) is a major cause of heart failure and transplantation in children. Despite advances in care, predicting outcomes remains difficult. Inflammatory markers, such as the neutrophil-to-lymphocyte ratio (NLR) and the systemic inflammatory index (SII), have demonstrated prognostic value in adults, but their role in pediatric DCM remains unclear. The present study aimed to assess the association of NLR, SII and other clinical, laboratory and echocardiographic parameters with mortality in pediatric DCM. In the present retrospective single-center study, 52 pediatric patients with DCM diagnosed between January 2000 and June 2021 were analyzed. Demographic, clinical, laboratory and echocardiographic data at diagnosis were collected from hospital electronic medical records. NLR and SII were calculated from complete blood counts, whereas mortality was the primary outcome. Statistical methods included receiver operating characteristic (ROC) curve analysis, Kaplan-Meier survival estimates and Cox regression. In the present study, 16 patients (30.8%) succumbed during follow-up, and NLR and SII were found to be significantly higher in deceased patients compared with survivors (P=0.003 and P=0.016, respectively). ROC analysis confirmed the predictive value of NLR (AUC, 0.785) and SII (AUC, 0.728). The optimal cut-off values were >2.75 for NLR and >1,428,898 for SII. Cox regression identified parameters associated with mortality, including low serum sodium and magnesium levels, elevated NLR and SII, reduced mitral E wave velocity and positive family history of DCM. In conclusion, elevated NLR and SII at diagnosis are associated with increased mortality in pediatric patients with DCM. As cost-effective and easily accessible markers of systemic inflammation, these indices may serve as useful adjuncts to conventional risk assessment, particularly in settings with limited access to advanced laboratory testing. However, further prospective multicenter studies are needed to validate their prognostic role.