# Serum Neuron-Specific Enolase as a Predictor of Neurological Outcomes at Hospital Discharge in Post-Cardiac Arrest Patients: A Prospective Study

## TL;DR

This study shows that measuring a brain injury biomarker called NSE 24-72 hours after cardiac arrest can predict neurological outcomes at hospital discharge.

## Contribution

The study identifies 72-hour NSE as a strong predictor of neurological outcomes in post-cardiac arrest patients.

## Key findings

- NSE levels at 24 and 72 hours were significantly higher in patients with unfavorable outcomes.
- NSE at 72 hours had 82% sensitivity and 90% specificity for predicting poor outcomes.
- The area under the curve for NSE was 0.89 at 72 hours, indicating strong predictive accuracy.

## Abstract

Background

Post-cardiac arrest encephalopathy is a major determinant of outcome in patients who achieve return of spontaneous circulation (ROSC). Despite advances in post-resuscitation care, accurately predicting neurological prognosis remains challenging. Serum neuron-specific enolase (NSE) is a validated biomarker of hypoxic-ischemic brain injury, although optimal time points and thresholds require further clinical evaluation.

Objective

This prospective study assessed the prognostic value of serum NSE measured at 24 and 72 hours after cardiac arrest in predicting neurological outcome at hospital discharge using the Cerebral Performance Category (CPC) scale.

Methods

We conducted a prospective observational study at County Emergency Clinical Hospital of Sibiu over a 12-month period (February 2024-February 2025). A total of 135 patients with post-cardiac arrest syndrome were admitted, of whom 120 met the inclusion criteria. Serum NSE levels were measured at 24 and 72 hours post-ROSC. Neurological outcome at discharge was categorized as favorable (Cerebral Performance Category, (CPC 1-2)) or unfavorable (CPC 3-5). Discrimination was evaluated using receiver operating characteristic (ROC) curves, and optimal cutoff values were identified using Youden’s index.

Results

Of the 120 included patients, 20 (17%) survived to hospital discharge. Median NSE concentrations at both 24 and 72 hours were significantly higher in patients with unfavorable outcomes (p< 0.001). NSE demonstrated good discriminative accuracy, with an AUC of 0.80 at 24 hours and 0.89 at 72 hours. The optimal prognostic cutoff at 72 hours was 68 ng/mL, yielding 82% sensitivity and 90% specificity for predicting an unfavourable outcome.

Conclusions

Serum NSE levels measured 24-72 hours after cardiac arrest are a reliable predictor of neurological outcome at hospital discharge. The strongest discriminative performance was observed at 72 hours. Incorporating NSE into a multimodal prognostication framework may enhance early risk assessment and guide clinical decision-making in post-cardiac arrest care.