Abstract 246: Therapeutic Hypothermia Mimicking Peptide Administration During Cardiopulmonary Resuscitation Improved Cardiac Arrest Survival in Swine

Abstract

Background: Out-of-hospital sudden cardiac arrest is a leading cause of death in the United States, affecting over 350,000 people per year with an overall survival rate around 10%. CPR, defibrillation, and therapeutic hypothermia are common resuscitation strategies, but hypothermia is difficult to implement timely to achieve survival benefit. A cell-permeable peptide TAT-PHLPP9c has been shown to alter metabolic pathways similar to hypothermia, and decreases the release of two biomarkers, taurine and glutamate, during the high osmotic stress of heart stunning and brain injury in a mouse arrest model. Hypothesis: TAT-PHLPP9c, given during CPR, enhances 24-hour survival in a swine ventricular fibrillation (VF) model. Methods: In 14 (8 controls and 6 treated) sedated, intubated, and mechanically ventilated swine, after 5 min of VF, ACLS with vest CPR and periodic defibrillations was performed. Venous blood samples were collected at baseline, after 2 min of CPR, and at 2 and 30 min after return of spontaneous circulation (ROSC). The animals were survived up to 24 hrs and plasma samples were analyzed for glutamate and taurine in 2 controls and 1 animal given peptide. Results: Three of the control animals had ROSC, but none survived for 24 hrs, while 4 of 6 treated animals achieved neurologically intact survival at 24 hrs (p < 0.02). Compared to baseline, both taurine and glutamate plasma concentrations increased in the control group, but the increase was reduced substantially by the peptide treatment at 30 min after ROSC (Figure). Conclusion: The use of the cooling mimicking peptide TAT-PHLPP9c administered during CPR significantly improved 24-hour survival in this swine model of cardiac arrest. It reduced the increase of cerebral and myocardial metabolic biomarkers, which encourages utilizing a strategy of cell-permeable peptides for intravenous administration for more rapid onset of hypothermia-like salutary effects than are possible with current CPR cooling devices.