Neuron specific enolase and S-100B as predictors of outcome after cardiac arrest and induced hypothermia

Aim: To assess the prognostic value of repetitive serum samples of neuron specific enolase (NSE) and S-100B in cardiac arrest patients treated with hypothermia. Methods: In a three-centre study, comatose patients after cardiac arrest were treated with hypothermia at 33 C for 24 h, regardless of cause or the initial rhythm. Serum samples were collected at 2, 24, 48 and 72 h after the arrest and analysed for NSE and S-100B in a non-blinded way. The cerebral performance categories scale (CPC) was used as the outcome measure; a best CPC of 1-2 during 6 months was regarded as a good outcome, a best CPC of 3-5 a poor outcome. Results: One centre was omitted in the NSE analysis due to missing 24 and 48 h samples. Two partially overlapping groups were studied, the NSE group (n = 102) and the S-100B group (n = 107). NSE at 48 h >28 mu g/l (specificity 100%, sensitivity 67%) and S-100B >0.51 mu g/l at 24 h (specificity 96%, sensitivity 62%) correlated with a poor outcome, and so did a rise in NSE of >2 mu g/l between 24 and 48 h (odds ratio 9.8, CI 3.5-27.7). A majority of missing samples (n = 123) were from the 2 h sampling time (n = 56) due to referral from other hospitals or inter-hospital transfer. Conclusion: NSE was a better marker than S-100B for predicting outcome after cardiac arrest and induced hypothermia. NSE above 28 mu g/l at 48 h and a rise in NSE of more than 2 mu g/l between 24 and 48 h were markers for a poor outcome. (C) 2009 Elsevier Ireland Ltd. All rights reserved.