Discordant neuron-specific enolase and neurologic outcomes in out-of-hospital cardiac arrest: a decade-long analysis.

Abstract

To characterize the clinical profiles of out-of-hospital cardiac arrest (OHCA) survivors stratified according to peak neuron-specific enolase (NSE) concentrations measured within 72 h of arrest, and to identify independent clinical determinants of outcomes in patients exhibiting discordance between NSE levels and neurological status. This retrospective cohort study included comatose adult OHCA survivors who underwent targeted temperature management between 2014 and 2024. Patients were categorized based on peak NSE levels into normal (<17 μg/L), intermediate (17-60 μg/L), and high (≥60 μg/L) groups. The primary endpoint was poor neurological outcome at 6 months, defined as a Cerebral Performance Category score of 3-5. Least Absolute Shrinkage and Selection Operator penalized logistic regression was performed. Among 646 patients, 193 (29.9%) had normal, 182 (28.2%) intermediate, and 271 (41.9%) high NSE levels. The specificity of a peak NSE ≥60 μg/L for poor neurological outcomes was 98.5%. Within the normal NSE group, 26.4% (51/193) had poor outcomes, independently associated with older age, non-shockable rhythm, non-cardiac etiology, higher PaO₂, and elevated lactate. In the intermediate NSE group, 71.4% (130/182) had poor outcomes, independently associated with a non-shockable rhythm, higher initial Sequential Organ Failure Assessment scores, and a lower gray-to-white matter ratio on brain computed tomography. In patients with normal NSE levels, poor outcomes appear to be driven primarily by age and systemic physiological derangements. In the intermediate NSE group, outcomes reflect the combined effects of the initial hemodynamic insult, systemic organ dysfunction, and early cerebral edema, highlighting the importance of a multimodal prognostic approach.