The Combination of Biomarkers for Prognostication of Long-Term Outcome in Patients Treated with Mild Hypothermia After Out-of-Hospital Cardiac Arrest—A Pilot Study

Abstract

To explore if the brain biomarker neuron-specific enolase (NSE) in combination with a biomarker for stress; CT-proAVP (copeptin), oxidation; peroxiredoxin 4 (Prx4), inflammation; procalcitonin (PCT), or with biomarkers from the heart; midregional proatrial natriuretic peptide (MR-proANP), or troponin T (TnT) can improve the prognostic accuracy of long-term outcome after out-of-hospital cardiac arrest (OHCA). Serum samples from cardiac arrest patients, treated at 33°C for 24 hours, were collected serially at 12, 24, and 48 hours after cardiac arrest. The concentration of the investigated biomarkers was measured using stored samples, and long-term outcome was evaluated by the cerebral performance category (CPC) at 6 months. Poor outcome was defined as CPC 3-5. Sixty-two patients with OHCA of presumed cardiac cause were included. NSE had best prognostic accuracy for poor outcome at 48 hours with a receiver operating characteristic area under curve (AUC) of 0.94 (95% confidence interval [CI] 0.87-1). The combination of NSE with TnT, both at 48 hours, increased the AUC to 0.98 (95% CI 0.95-1, likelihood ratio [LR] test p-value 0.07, net reclassification index [NRI] <0.001); NSE and MR-proANP, both at 12 hours, yielded an AUC of 0.91 (95% CI 0.80-1, LR test p-value 0.0014, NRI p-value 0.003); NSE at 48 hours with MR-proANP at 12 hours yielded an AUC of 0.97 (95% CI 0.92-1, LR test p-value 0.055, NRI p-value 0.04). This pilot study suggests that a combination of biomarkers with NSE could be beneficial for improving early prognostication of long-term outcome following OHCA.