Change in neuron specific enolase levels in out-of-hospital cardiopulmonary arrest survivors as a simple and useful tool to predict neurological prognosis.

Introduction And Objectives: Neuron-specific enolase (NSE) is a prognostic marker in out-of-hospital cardiopulmonary arrest (OHCA) survivors treated with mild therapeutic hypothermia (MTH). The objectives were to analyze the correlation between dynamic changes in NSE and outcomes and to determine the measurement timing that best predicts neurological status.

Methods: Multicenter cohort study including patients admitted after shockable rhythm OHCA and treated with MTH. Serum NSE was sampled at 2 different times and Δ-NSE (%) was calculated as 100 x (NSE2-NSE1)/NSE1. In-hospital mortality and neurological outcome, as assessed by the Cerebral Performance Category (CPC) scale, were evaluated during admission and after a 6-month follow-up.

Results: We included 166 patients admitted to 4 hospitals. In-hospital mortality was 31.9%. Almost 60% of patients had a good neurological recovery (CPC 1-2). On univariate and multivariate logistic regression analyses, an increase in NSE levels was associated with higher in-hospital mortality and worse CPC on discharge and after 6-months (P<.001). Positive Δ-NSE showed an OR=9.28 (95% CI 4.40-19.57) for mortality, OR=11.23 (95% CI 5.24-24.11) for CPC 3-5 at discharge and OR=11.14 (95% CI 5.05-24.55) for CPC 3-5 after 6-months' follow-up (P<.001). The first NSE measurement, conducted at 18 to 24hours, and the second measurement at 69 to 77hours after OHCA showed a high area under the curve in predicting CPC at discharge (0.9389 and 0.9909, respectively; 0.8096 for the whole cohort).

Conclusions: Dynamic changes in NSE serum levels are good markers of hard clinical outcomes after an OHCA due to shockable rhythm in an MTH-treated cohort. NSE measurements at specific intervals after OHCA may predict events even more precisely.