Neuron-specific enolase concentrations for the prediction of poor prognosis of comatose patients after out-of-hospital cardiac arrest: An observational cohort study

Abstract

Background: Neuron-specific enolase (NSE) is a biomarker for neurological outcomes after cardiac arrest with the most evidence collected thus far; however, recommended prognostic cutoff values are lacking owing to the discrepancies in the published data. Aims: The aim of the study was to establish NSE cutoff values for prognostication in the environment of a cardiac intensive care unit following out-of-hospital cardiac arrest (OHCA). Methods: A consecutive series of 82 patients admitted after OHCA were enrolled. Blood samples for the measurement of NSE levels were collected at admission and after 1 hour, 3, 12, 24, 48, and 72 hours. Neurological outcomes were quantified using the cerebral performance category (CPC) index. Each patient was classified into either the good (CPC ≤2) or poor prognosis (CPC ≥3) group. Results: Median NSE concentrations were higher in the poor prognosis group, and the difference reached statistical significance at 48 and 74 hours (84.4 ng/ml vs 22.9 ng/ml at 48 hours and 152.1 ng/ml vs 18.7 ng/ml at 72 hours; P <0.001, respectively). Moreover, in the poor prognosis group, NSE increased significantly between 24 and 72 hours (P <0.001). NSE cutoffs for the prediction of poor prognosis after OHCA were 39.8 ng/ml, 78.7 ng/ml, and 46.2 ng/ml for 24, 48, and 72 hours, respectively. The areas under the curve were significant at each time point, with the highest values at 48 and 72 hours after admission (0.849 and 0.964, respectively). Conclusions: Elevated NSE concentrations with a rise in levels in serial measurements may be utilized in the prognostication algorithm after OHCA.