Vasoactive-inotropic score, inflammatory indices, and biochemical markers as early predictors of fulminant myocarditis in critically Ill children: a PICU-based retrospective cohort study

Fulminant myocarditis is a life-threatening condition associated with high mortality in critically ill children, and early identification of patients at risk for fulminant progression remains challenging. This study aimed to evaluate the prognostic value of the Vasoactive-Inotropic Score (VIS), serum albumin, systemic inflammatory indices, and conventional biomarkers in predicting fulminant myocarditis and composite adverse outcomes in pediatric intensive care unit (PICU)–admitted children with acute myocarditis. This single-center retrospective cohort study included 71 children (aged 1 month–18 years) admitted to the 30-bed PICU of Gaziantep City Hospital between January 2024 and January 2026 with a primary diagnosis of acute myocarditis. Patients were classified as fulminant (requiring inotropic or mechanical circulatory support due to hemodynamic disturbance) or non-fulminant. The composite adverse outcome comprised in-hospital mortality, extracorporeal membrane oxygenation (ECMO), continuous renal replacement therapy (CRRT), or invasive mechanical ventilation. All biomarkers were measured within the first 6 h of PICU admission. Children with concomitant sepsis or septic shock at PICU admission were excluded. Receiver operating characteristic (ROC) curve analysis was performed to determine optimal cut-off values and the area under the curve (AUC). Of 71 patients (median age 8.4 years; 59.2% male), 21 (29.6%) had fulminant myocarditis and 27 (38.0%) experienced the composite adverse outcome. In-hospital mortality was 66.7% in the fulminant group versus 0% in non-fulminant patients. The VIS demonstrated the highest discriminatory performance (AUC = 0.993; cut-off 14.2; sensitivity 95.2%, specificity 98.0%), followed by admission left ventricular ejection fraction (LVEF; AUC = 0.936) and serum albumin (AUC = 0.921). For the composite adverse outcome, LVEF (AUC = 0.931), VIS (AUC = 0.902), and albumin (AUC = 0.894) were the strongest predictors; lactate > 3.0 mmol/L achieved 100% specificity. Among the inflammatory indices, the systemic inflammatory response index (SIRI; AUC = 0.827) and the systemic immune-inflammation index (SII; AUC = 0.817) showed good discriminatory capacity, whereas the neutrophil-to-lymphocyte ratio (NLR) performed poorly (AUC = 0.657, 95% CI: 0.470–0.814). In PICU-admitted children with acute myocarditis, the VIS and serum albumin — both readily available at the bedside — showed strong discriminatory performance for fulminant myocarditis and for composite adverse outcomes. Because the need for vasoactive support forms part of the clinical construct of fulminant myocarditis, the discriminatory performance of the VIS for that particular endpoint should be interpreted with appropriate caution. Every child with an admission lactate > 3.0 mmol/L experienced a composite adverse outcome (specificity 100%, positive predictive value 100%), although a lactate at or below this threshold did not exclude an adverse outcome (sensitivity 70.4%). These cost-effective parameters may facilitate early risk stratification and timely escalation of care. Not applicable.