Mattsson N, et al. - This study was planned to test serum tau as a predictor of neurological outcome after cardiac arrest. As per findings, serum tau proved a promising novel biomarker for prediction of neurological outcome in patients with cardiac arrest. It seemed significantly better in comparison to serum NSE, which is recommended in guidelines and currently used in clinical practice in several countries to predict outcome after cardiac arrest.

Methods

• The neuronal protein tau in serum was determined at 24, 48, and 72 h after cardiac arrest in 689 patients in the prospective international Target Temperature Management trial.
• Main outcome assessed included poor neurological outcome, defined as Cerebral Performance Category 3-5 at 6 months.

Results

• At 6 months after cardiac arrest, increased tau seemed linked with poor outcome (median 38.5 [IQR 5.7-245] ng/L in poor versus 1.5 [0.7-2.4] ng/L in good outcome, for tau at 72 h, p<0.0001).
• Compared to using clinical information, tau enhanced prediction of poor outcome (p<0.0001).
• For good outcome, tau cut-offs indicated low false positive rates (FPR) while retaining high sensitivity for poor outcome; for instance, tau at 72 h had FPR 2% (95% CI 1-4%) with sensitivity 66% (95% CI 61-70%).
• Tau indicated higher accuracy in comparison to serum NSE (the area under the receiver operating characteristic curve was 0.91 for tau versus 0.86 for NSE at 72 hours, p=0.00024).
• During follow-up (up to 956 days), there appeared a marked association between tau and overall survival.
• For patients randomized to 33°C and 36°C targeted temperature after cardiac arrest, the accuracy to predict outcome by serum tau remained equally high.