Neuron-specific Enolase Concentrations for the Prediction of Poor Prognosis of Comatose Patients after Out-of-hospital Cardiac Arrest: an Observational Cohort Study

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 significance at 48 and 74 h (84.4 ng/ml versus 22.9 ng/ml at 48 h and 152.1 ng/ml versus 18.7 ng/ml at 72 h, P < 0.001). Moreover, in the poor prognosis group, NSE increased significantly between 24 and 72 h (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 h, respectively. The areas under the curve were significant at each time point, with the highest values at 48 and 72 h after admission (0.849 and 0.964, respectively). Conclusion: Elevated NSE concentrations with a rise in levels in serial measurements may be utilized in the prognostication algorithm after OHCA.