Serum ferritin and clinical outcomes in children undergoing pediatric cardiac surgery

Abstract Introduction Hyperferritinemia is a prognostic marker in critical illness, but its role in postoperative outcomes of pediatric congenital heart defects remains poorly defined, especially in resource-limited settings. This study evaluated early serum ferritin as a predictor of outcomes after congenital heart surgery and its association with the PIM 3 score. Methods A single-center, prospective cohort study was conducted from April 2023 to October 2024 at a tertiary referral center in southeastern Brazil. Patients aged 29 days to 18 years, of both sexes, admitted to the PICU after congenital heart surgery were included and categorized as cyanotic or acyanotic. Statistical significance was defined as two-sided p < 0.05. Results A total of 105 patients were included. Median ferritin was higher in patients with PICU stays < 7 days (183 ng/mL; p = 0.004) and was significantly associated with a PIM 3 score ≥ 5% (642 ng/mL; p < 0.006). Cyanotic patients had longer PICU stays (11.0 vs. 7.2 days; p = 0.02), longer use of vasoactive drugs (3.8 vs. 2.6 days; p = 0.01), and accounted for all deaths ( p < 0.001). Hemoglobin and hematocrit were also significantly higher in cyanotic patients (14 vs. 13 g/dL and 40% vs. 37%; p < 0.001). Conclusions Serum ferritin may serve as a marker of secondary outcomes and aid early risk stratification in congenital heart defects patients in the PICU.