A Review of Serum Biomarkers for Neurologic Prognostication After Cardiac Arrest

Neurologic prognostication for comatose survivors of cardiac arrest is a complex task with a profound impact on clinical outcomes. Laboratory biomarkers provide objective data with regard to the degree of cerebral injury and can contribute to establishing the overall prognosis. This review provides a comprehensive overview of all laboratory markers currently utilized both in the clinical and research settings. Biomarkers currently under investigation have a wide range of features, which make for a challenging integration into prognostication protocols and models; these include different half-lives, presence in nonneuronal tissues, metabolic characteristics, and detection characteristics. Ultimately, each of these properties results in variable sensitivity and specificity with regard to predicting neurologic outcome. Neuron-specific enolase is the only biomarker widely used in clinical practice at this time. Tau, glial fibrillary acidic protein, and neurofilament light chain are promising investigational markers that have been studied in large clinical trials, with neurofilament light chain having the strongest characteristics in discriminating between good and poor neurologic outcomes. The characteristics and potential role as biomarkers are also reviewed for ubiquitin C-terminal hydrolase L1 protein, S100B protein, interleukins, and microRNAs.