# Prognostic value of neutrophil-lymphocyte ratio, absolute lymphocyte count, and thrombocyte-lymphocyte ratio in predicting the outcomes of tetralogy of fallot primary repair

## TL;DR

The study finds that the neutrophil-lymphocyte ratio (NLR) is a useful and accessible predictor of surgical complications in patients undergoing Tetralogy of Fallot repair.

## Contribution

The novel contribution is identifying NLR as a cost-effective biomarker for predicting postoperative complications in Tetralogy of Fallot surgery.

## Key findings

- Elevated NLR was weakly correlated with higher complication burdens in ToF patients.
- NLR showed the strongest predictive value among the three biomarkers tested for surgical complications.
- The study reported high complication rates and prolonged hospital stays following ToF repair.

## Abstract

Tetralogy of Fallot (ToF) is a chronic hypoxic condition that increases the risk of inflammatory responses during surgery. However, many inflammatory biomarkers used to predict surgical outcomes are costly and not widely accessible. This single-center, retrospective observational study aimed to compare the prognostic value of neutrophil-lymphocyte ratio (NLR), absolute lymphocyte count (ALC), and thrombocyte-lymphocyte ratio (TLR) in predicting outcomes of ToF primary repair. Between January 2020 and December 2022, 501 patients underwent ToF primary repair. Our findings revealed low postoperative reoperation (6.5%) and 30-day mortality (4.7%) rates, but prolonged LOS (92.2%) and a high complication rate (84%), with grade IVa (27.9%) and grade I (26.4%) complications being the most common. Elevated NLR (r = 0.132, p = 0.014), female gender (r = 0.117, p = 0.027), associated diagnoses (r = 0.104, p = 0.047), and prolonged surgical duration (r = 0.176, p = 0.001) were linked to higher complication burdens, though the correlations were weak. Among the three indexes, preoperative NLR demonstrated the strongest predictive value for complications, despite its low sensitivity and specificity. Given its accessibility and cost-effectiveness, NLR may serve as a useful tool for identifying high-risk patients and improving postoperative monitoring. Future multicenter prospective studies are necessary to validate the prognostic value of preoperative NLR under standardized conditions, across a broader patient population, and with more comprehensive confounding variables adjustments, ultimately improving ToF surgical outcomes (Clinical Trial NCT05976204).