Neuron-specific enolase and S-100b in prolonged targeted temperature management after cardiac arrest: A randomised study.

BACKGROUND: We aimed to investigate the impact of prolonged targeted temperature management (TTM) in cardiac arrest patients on release of serum levels of NSE and S-100b and their prognostic performances.

METHODS: This is a substudy of the Targeted Temperature Management for 24 vs 48h trial. NSE and S-100b levels were analysed retrospectively in serum samples collected upon admission, at 24, 48, and 72h after reaching the target temperature of 33±1°C. The primary outcome was biomarker serum concentrations and secondary outcome was the cerebral performance category score after 6 months.

RESULTS: 115 patients from two centres were analysed. NSE and S-100b levels did not differ between TTM groups at any single time-point. Poor outcome patients had higher biomarker levels at 24, 48, and 72h: NSE: 9.73 (7.2; 10.9) versus 20.40 (12.7; 27.2), 8.86 (6.6; 9.6) versus 17.47 (11.1; 37.3) and 6.23 (5.3; 8.5) versus 31.05 (12.8; 52.5) respectively and S-100b: 0.09 (0.07; 0.11) versus 0.23 (0.19; 0.39), 0.08 (0.07; 0.09) versus 0.18 (0.15; 0.33) and 0.07 (0.06; 0.08) versus 0.13 (0.09; 0.23). The daily changes in NSE from admission to Day 2 after the cardiac arrest (CA) were also related to the outcome (p=0.003 and p=0.02). The best prediction of outcome was found at 72h for NSE and at 24h as well as 48h for S100b.

CONCLUSIONS: No clinically relevant differences were found in the levels of NSE or S-100b between standard and prolonged TTM. Prognostic reliability of NSE and S-100b was unaltered by prolonged TTM.