Neurofilament light as an outcome predictor after cardiac arrest: a post hoc analysis of the COMACARE trial

PURPOSE: Neurofilament light (NfL) is a biomarker reflecting neurodegeneration and acute neuronal injury, and an increase is found following hypoxic brain damage. We assessed the ability of plasma NfL to predict outcome in comatose patients after out-of-hospital cardiac arrest (OHCA). We also compared plasma NfL concentrations between patients treated with two different targets of arterial carbon dioxide tension (PaCO(2)), arterial oxygen tension (PaO(2)), and mean arterial pressure (MAP). METHODS: We measured NfL concentrations in plasma obtained at intensive care unit admission and at 24, 48, and 72 h after OHCA. We assessed neurological outcome at 6 months and defined a good outcome as Cerebral Performance Category (CPC) 1–2 and poor outcome as CPC 3–5. RESULTS: Six-month outcome was good in 73/112 (65%) patients. Forty-eight hours after OHCA, the median NfL concentration was 19 (interquartile range [IQR] 11–31) pg/ml in patients with good outcome and 2343 (587–5829) pg/ml in those with poor outcome, p < 0.001. NfL predicted poor outcome with an area under the receiver operating characteristic curve (AUROC) of 0.98 (95% confidence interval [CI] 0.97–1.00) at 24 h, 0.98 (0.97–1.00) at 48 h, and 0.98 (0.95–1.00) at 72 h. NfL concentrations were lower in the higher MAP (80–100 mmHg) group than in the lower MAP (65–75 mmHg) group at 48 h (median, 23 vs. 43 pg/ml, p = 0.04). PaCO(2) and PaO(2) targets did not associate with NfL levels. CONCLUSIONS: NfL demonstrated excellent prognostic accuracy after OHCA. Higher MAP was associated with lower NfL concentrations. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00134-020-06218-9) contains supplementary material, which is available to authorized users.