Abstract 104: Taurine As Biomarker And Therapeutic Target For Cardiac Arrest

Introduction: Out-of-hospital cardiac arrest (CA) is a leading cause of death with high mortality. Most patients die from post-CA syndrome due to ischemia/reperfusion injury-triggered responses. Taurine and glutamate, amino acids with cellular activities that are expressed primarily in heart and brain tissues, respectively, are released in response to CA. Hypothesis: Taurine and glutamate levels in blood reflect the extent of injury of CA. Taurine and glutamate could potentially regulate CA outcomes. Methods: Adult CA patients (n=51, 19 survivors, S and 32 nonsurvivors, NS; 35 received cooling treatment, C while 16 did not, NC) at an urban academic ED were enrolled from 2018-2019. Plasma taurine and glutamate collected at various time points including hospital arrival, 6, 24, 48 and 72 hours after arrival, and measured with commercially available assay kits. In a mouse model, 8-min asystolic cardiac arrest was induced with KCl, followed by initiation of CPR and randomized to blinded administration of taurine (50 mg/kg) or saline placebo at 90 second during CPR. Survival (4h) and mean arterial blood pressure (MAP) were evaluated. The Wilcoxon test and generalized estimating equation were used for comparison at each time point and longitudinal trend analysis for human data. Kaplan-Meier estimate and T-test were used for survival and mean comparison in mice. p <0.05 was considered statistically significant. Results: Plasma taurine and glutamate levels were highest at R0 and decreased over time in both S and NS, and were higher in NS than S. Taurine levels were significantly associated with survival (NS 66.24±41.36 vs. S 37.48±19.46 at 6h, p <0.05) while glutamate levels were not. Taurine levels in both C and NC groups demonstrated a significantly decreasing trend over time, but the C group showed more reduction ( p <0.05), while glutamate levels showed no significant trend. In mice, compared to saline, taurine treatment markedly improved 4h survival and MAP post-ROSC. Conclusions: Decreased release of taurine into blood is correlated with CA survival and may regulate CA outcomes. It has high translational potential as a biomarker for predicting CA survival, guiding cooling treatment, and serving as a therapeutic target to improve CA outcomes.