A Novel Marker for Predicting Fulminant Myocarditis: Systemic Immune-Inflammation Index

Area of Science:

• Pediatric Cardiology
• Pediatric Inflammation
• Biomarker Discovery

Background:

• Myocarditis requires effective prognostic biomarkers for timely risk stratification and improved clinical decision-making.
• The prognostic value of the systemic immune-inflammatory index (SII) in pediatric fulminant myocarditis remains unassessed.

Purpose of the Study:

• To determine the prognostic effect of SII and other inflammatory markers in pediatric myocarditis.
• To identify factors associated with adverse outcomes in pediatric myocarditis.

Main Methods:

• Retrospective analysis of 106 children (1 month to 18 years) diagnosed with myocarditis.
• Evaluation of inflammatory markers including SII, white blood cell count (WBC), and absolute neutrophil count (ANC).
• Assessment of correlation between SII and left ventricular ejection fraction (LVEF).

Main Results:

• Fulminant myocarditis occurred in 15% of patients.
• Median SII was significantly higher in the fulminant myocarditis group (1927) compared to the non-fulminant group (351) (p < 0.001).
• SII, ANC, and WBC demonstrated high area under the curve (AUC) values for predicting fulminant myocarditis (AUCs 0.92, 0.94, and 0.87, respectively).
• SII showed a significant negative correlation with LVEF (r = -0.576, p < 0.001).

Conclusions:

• The systemic immune-inflammatory index (SII) is a valuable and independent predictor of prognosis in pediatric myocarditis.
• SII, derived from routine blood tests, facilitates early recognition of adverse outcomes in children with myocarditis.
• ANC and WBC also show significant potential in predicting fulminant myocarditis in pediatric patients.