Abstract 218: Novel Blood Biomarker Taurine and Glutamate for Early Predicting Outcomes After Out-of-hospital Cardiac Arrest

Abstract

Introduction: Out-of-Hospital cardiac arrest (OHCA) is the leading cause of death with an overall survival rate of less than 10%. Organ failure and metabolic impairment are two critical elements of post-CA syndrome. Taurine and glutamate are amino acids that are expressed primarily in heart and brain. The compensatory release during osmotic stress, as seen in CA, amplifies reperfusion injury, heart stunning and brain edema. Thus, taurine and glutamate concentrations in blood likely reflects the extent of injury in the heart and brain following CA. Hypothesis: Plasma taurine and glutamate concentration correlates with CA outcomes. Methods: Adult OHCA patients (n=37) at an urban academic ED were enrolled from 2018-2019. Among them, 14 were survivors (S) and 23 were nonsurvivors (NS). Blood samples were collected at various time points including the time at hospital arrival, 6, 24, 48, 72 hours after arrival (T0, 6, 24, 48 and 72 h, respectively), and measured. T-test and GEE were used for mean comparison and longitudinal trend analysis, respectively. p < 0.05 was considered as statistically significant. Results: Plasma taurine and glutamate concentrations were compared between S and NS at T0 and across all time points. Both concentrations were significantly higher in NS vs S group at T0 (for taurine: 77.7 ± 40.0 in NS vs. 60.0 ± 31.9 μM in S, p =0.014; for glutamate: 176.4 ± 98.7 in NS vs. 162.8 ± 111.1 μM in S, p =0.0496), and showed a decreasing trend over time. In the first 6 h, taurine and glutamate level decreased more in S group than NS group (over 30% drop in S compared to <15% drop in NS). In addition, a positive correlation of cerebral performance category was seen at T6 with taurine (p=0.0354), but not with glutamate. Conclusions: Blood taurine and glutamate may serve as early biomarkers in predicting OHCA outcomes. Monitoring their change over time can help physicians tailor treatment decisions and patient management.