Preoperative Neutrophil-Lymphocyte Ratio Can Predict Outcomes for Patients Undergoing Tetralogy of Fallot Repair

From heart to gut: Exploring the gut microbiome in congenital heart disease

Congenital heart disease (CHD) is a prevalent birth defect and a significant contributor to childhood mortality. The major characteristics of CHD include cardiovascular malformations and hemodynamical disorders. However, the impact of CHD extends beyond the circulatory system. Evidence has identified dysbiosis of the gut microbiome in patients with CHD. Chronic hypoxia and inflammation associated with CHD affect the gut microbiome, leading to alterations in its number, abundance, and composition. The gut microbiome, aside from providing essential nutrients, engages in direct interactions with the host immune system and indirect interactions via metabolites. The abnormal gut microbiome or its products can translocate into the bloodstream through an impaired gut barrier, leading to an inflammatory state. Metabolites of the gut microbiome, such as short-chain fatty acids and trimethylamine N-oxide, also play important roles in the development, treatment, and prognosis of CHD. This review discusses the role of the gut microbiome in immunity, gut barrier, neurodevelopment, and perioperative period in CHD. By fostering a better understanding of the cross-talk between CHD and the gut microbiome, this review aims to contribute to improve clinical management and outcomes for CHD patients.

The role of neutrophil-to-lymphocyte ratio in predicting mortality after bidirectional Glenn procedure

This study aimed to address the role of various inflammation-related blood indices for the assessment of in-hospital outcomes in subjects undergoing Glenn procedure. Subjects who underwent the Glenn procedure for hypoplastic left heart syndrome were analysed retrospectively. Subjects were divided into two groups: Group 1 consisted of 78 patients who were discharged, and Group 2 included 12 patients who died after surgery. Post-operative third-day neutrophil count and neutrophil-to-lymphocyte ratio value were significantly higher in the exitus group compared to the discharged group (p = 0.006 and p = 0.003, respectively). Third-day neutrophil-to-lymphocyte ratio was positively correlated with duration of intubation (r = 0.253, p = 0.018), length of stay in ICU (r = 0.296, p = 0.006) and length of hospital stay (r = 0.297, p = 0.005). Multiple logistic regression analysis revealed that patients with high third-day neutrophil-to-lymphocyte ratio (≥6) had 14.227-fold higher risk of death compared to those with lower values. In addition, higher pulmonary arterial pressure was associated with increased risk of death. Receiver operating characteristics analysis revealed that neutrophil-to-lymphocyte ratio had 66.67% sensitivity, 84% specificity, 81.61% accuracy, 40.00% positive predictive value and 94.03% negative predictive value with a cut-off point of ≥6 to predict mortality. Third-day neutrophil-to-lymphocyte ratio and increased post-operative pulmonary arterial pressure are significant predictors for in-hospital mortality in Glenn procedure recipients. A cut-off value of ≥6 for third-day neutrophil-to-lymphocyte ratio predicts mortality with 66.67% sensitivity and 84% specificity. Given its simplicity and availability, post-operative neutrophil-to-lymphocyte ratio should be monitored on a daily basis to identify patients with high risk for mortality after Glenn procedure.

Neutrophil-Lymphocyte Ratio in Congenital Heart Surgery: What Is Known and What Is New?

Operative mortality after repair of congenital heart disease has improved dramatically over the past few decades. Nevertheless, there is always room for the additional mitigation of complications and mortality. Being able to anticipate adverse outcomes is clearly important, especially when using low-cost and easily accessible resources. The neutrophil-lymphocyte ratio (NLR) is defined as the ratio of the absolute neutrophil to lymphocyte count, which can be easily measured using a regular white blood cell count. Recently, preoperative NLR has been shown to be a predictor of outcomes in patients undergoing congenital heart surgery. Although it presented promising results, there are still many gaps to be filled like the normal value for children, the ideal cutoff value to predict adverse outcomes, the wide variation and its correlation with other biomarkers, and if it is a modifiable risk factor. The aim of this review is to understand the prognostic value of preoperative NLR as a biomarker predictor of outcomes in patients undergoing congenital heart surgery based on previous clinical studies and to propose future directions in order to solve the above-mentioned questions.

The role of the neutrophil-lymphocyte ratio for pre-operative risk stratification of acute kidney injury after tetralogy of Fallot repair

INTRODUCTION

Acute kidney injury is a risk factor for chronic kidney disease and mortality after congenital heart surgery under cardiopulmonary bypass. The neutrophil-lymphocyte ratio is an inexpensive and easy to measure biomarker for predicting outcomes in children with congenital heart disease undergoing surgical correction.

OBJECTIVE

To identify children at high risk of acute kidney injury after tetralogy of Fallot repair using the neutrophil-lymphocyte ratio.

METHODS

This single-centre retrospective analysis included consecutive patients aged < 18 years who underwent tetralogy of Fallot repair between January 2014 and December 2018. The pre-operative neutrophil-lymphocyte ratio was measured using the last pre-operative complete blood count test. We used the Acute Kidney Injury Network definition.

RESULTS

A total of 116 patients were included, of whom 39 (33.6%) presented with acute kidney injury: 20 (51.3%) had grade I acute kidney injury, nine had grade II acute kidney injury (23.1%), and 10 (25.6%) had grade III acute kidney injury. A high pre-operative neutrophil-lymphocyte ratio was associated with grade III acute kidney injury in the post-operative period (p = 0.04). Patients with acute kidney injury had longer mechanical ventilation time (p = 0.023), intensive care unit stay (p < 0.001), and hospital length of stay (p = 0.002).

CONCLUSION

Our results suggest that the pre-operative neutrophil-lymphocyte ratio can be used to identify patients at risk of developing grade III acute kidney injury after tetralogy of Fallot repair.