Validation of neuron-specific enolase in cardiac arrest patients with limited withdrawal of life-sustaining therapy

Aim: We validated the prognostic performance of neuron-specific enolase (NSE) according to the recommended values in cardiac arrest (CA) survivors. Methods: We analyzed the data of adult CA survivors who underwent targeted temperature management between January 2014 and December 2020. We measured the NSE level 48 h and 72 h after CA. We performed receiver operating characteristics (ROC) and used the reference value (17 mu g/L) and the guidelines-suggested value (60 mu g/L) as thresholds. The primary outcome was 6-month neurological outcomes with Cerebral Performance Category (CPC), dichotomized into good (CPC 1 or 2) or poor (CPC 3-5). Results: Of the 513 included patients, 346 (67.4 %) patients had poor neurological outcomes. The area under ROC (AUC) of NSE at 48 h was 0.887 (95 % confidence intervals [CIs], 0.851-0.909) with the Youden index of 35.6 mu g/L. A false positive rate (FPR) of <2 % was observed (54.1 <mu>g/L). The thresholds values (17, 60) had a sensitivity of 86.1% and 56.7 % and a specificity of 66.7%and 98.8 %, respectively. The AUC of NSE at 72 h was 0.892 (95 % CIs, 0.849-0.920) with the Youden index of 30.4 mu g/L. The threshold values (17, 60) had a sensitivity of 86.0%and 59.4 % with a specificity of 72.2%and 98.3 %, respectively. An FPR of <2 % was observed (53.6 <mu>g/L). Among the 156 patients and 113 patients with NSE at 48 h and at 72 h <= 17 mu g/L, respectively, 109 and 83 patients had good neurological outcomes. Conclusions: The cut-off value of NSE (60 mu g/L) was acceptable to predict poor neurological outcomes with an FPR <2 % in cardiac arrest survivors, irrespective of at 48 or 72 h. NSE (17 <mu>g/L) can function as mitigating factor to deter early WLST.