sTREM-1 Concentrations in Children Undergoing Cardiac Surgery: Description of Biomarker Levels According to RACHS-1 and TISS-28 Categories

Congenital heart defects represent prevalent malformations requiring complex surgical interventions. Outcomes are influenced by clinical severity, inflammatory response, and complexity of care, highlighting the need for improved risk stratification tools. Objectives: To describe the behavior and distribution of perioperative sTREM-1 concentrations in a pediatric cohort undergoing cardiac surgery, exploratorily stratified by RACHS-1 and TISS-28 severity scores. Methods: A translational cross-sectional study was conducted with 32 children (aged 0–14 years) undergoing surgical correction for congenital heart disease at a Brazilian public referral hospital (2021–2022). Exclusion criteria included genetic syndromes, active infections, or previous cardiac surgeries. Clinical severity was assessed using RACHS-1 (mortality risk) and TISS-28 (care complexity) scores. Serum sTREM-1 levels were measured via ELISA preoperatively and postoperatively. Statistical analysis involved the Shapiro–Wilk normality test, descriptive statistics expressed as medians and interquartile ranges, and Spearman’s rank correlation coefficient to evaluate the relationship between sTREM-1 levels and severity scores, with significance set at p < 0.05. Results: The cohort consisted predominantly of males (56.25%), term infants (93.75%), with 50% presenting cyanosis. RACHS-1 category 3 was most common (34.37%), while TISS-28 category 2 predominated (40.62%). Most patients were discharged (93.75%). Preoperative sTREM-1 levels showed no significant correlation with RACHS-1 (r_s = 0.265; p = 0.143) or TISS-28 scores (r_s = 0.227; p = 0.212). Conversely, postoperative sTREM-1 concentrations significantly and positively correlated with both RACHS-1 (r_s = 0.356; p = 0.045) and TISS-28 categories (r_s = 0.394; p = 0.026), reflecting higher biomarker levels in more severe clinical scenarios. Conclusions: Postoperative sTREM-1 levels correlated significantly with surgical risk and clinical severity, showing higher median concentrations in more severe RACHS-1 and TISS-28 categories. Conversely, no preoperative correlation was observed, suggesting sTREM-1 primarily reflects postoperative inflammatory responses and surgical complexity.