Predictive role of perioperative neutrophil to lymphocyte ratio in pediatric congenital heart disease associated with pulmonary arterial hypertension

BACKGROUND: We aimed to explore the relationship between the neutrophil to lymphocyte ratio (NLR) and the early clinical outcomes in children with congenital heart disease (CHD) associated with pulmonary arterial hypertension (PAH) after cardiac surgery. METHODS: A retrospective observational study involving 190 children from January 2013 to August 2019 was conducted. Perioperative clinical and biochemical data were collected. RESULTS: We found that pre-operative NLR was significantly correlated with AST, STB, CR and UA (P < 0.05), while post-operative NLR was significantly correlated with ALT, AST, BUN (P < 0.05). Increased post-operative neutrophil count and NLR as well as decreased lymphocyte count could be observed after cardiac surgery (P < 0.05). Level of pre-operative NLR was significantly correlated with mechanical ventilation time, ICU stay time and total length of stay (P < 0.05), while level of post-operative NLR was only significantly correlated to the first two (P < 0.05). By using ROC curve analysis, relevant areas under the curve for predicting prolonged mechanical ventilation time beyond 24 h, 48 h and 72 h by NLR were statistically significant (P < 0.05). CONCLUSION: For patients with CHD-PAH, NLR was closely related to early post-operative complications and clinical outcomes, and could act as a novel marker to predict the occurrence of prolonged mechanical ventilation.