# Prognostic Value of Serum S100B Protein for Neurological Outcomes After Cardiac Arrest: A Systematic Review and Meta-Analysis

## TL;DR

This study finds that the protein S100B in blood can predict brain outcomes after cardiac arrest, helping doctors make better decisions.

## Contribution

This is the first systematic review and meta-analysis confirming S100B's reliability as an early biomarker for neurological prognosis after cardiac arrest.

## Key findings

- Lower S100B levels were strongly associated with better neurological outcomes after cardiac arrest.
- S100B showed high diagnostic accuracy with a pooled sensitivity of 0.63 and specificity of 0.93.
- Findings were consistent across different populations and time points, with minimal publication bias.

## Abstract

Background/Objectives: Cardiac arrest (CA) continues to be one of the leading causes of mortality and long-term neurological disability worldwide. Accurate early neuroprognostication after return of spontaneous circulation is essential for guiding post-resuscitation care. The calcium-binding astrocytic protein S100B has been identified as a potential biomarker for hypoxic–ischemic brain injury. This systematic review and meta-analysis assessed the prognostic and diagnostic efficacy of serum S100B in forecasting neurological outcomes after CA. Methods: Thorough searches of PubMed, Embase, Scopus, Web of Science, CENTRAL, and CINAHL from their inception to November 2025 uncovered 40 observational studies. Results: Pooled analyses employing random-effects models revealed markedly reduced S100B concentrations in patients with favourable neurological outcomes compared to those with unfavourable outcomes (standardized mean difference −1.78, 95%CI: −2.25 to −1.31; p < 0.001). The diagnostic accuracy was high, with pooled sensitivity and specificity of 0.63 and 0.93, respectively, and an area under the curve of 0.89 (95% CI 0.85–0.92). Subgroup and sensitivity analyses confirmed the robustness of these findings across various study populations and temporal points, with negligible evidence of publication bias. Conclusions: These results indicate that serum S100B is a reliable early biomarker of neurological prognosis after CA. Incorporating S100B into multimodal predictive frameworks may enhance post-resuscitation decision-making.