Rethinking The Treatment Of Cardiac Arrest To Include Non-oxygen Metabolite Supplementation: Plasma Lysophosphatidylcholine Level Maintenance After Cardiac Arrest Is Critical For Survival

Cardiac arrest (CA) is a loss of circulation that curtails the supply of oxygen and non-oxygen metabolites to the whole body resulting in ischemia and death. Subsequent resuscitation is vital for survival, but also causes reperfusion injury. Oxygen deprivation as one arm of ischemia-reperfusion injury and its relationship with death is well-established, but its counterpart, metabolite dysfunction, is overlooked and poorly understood. We have previously shown that many metabolites are not normalized as efficiently or rapidly after resuscitation especially, particularly those that are severely decreased after CA. As such, we hypothesize that appropriate replenishment of certain metabolites is essential for survival. Lysophosphatidylcholine (LPC), an important family of phospholipids, is an example of such non-oxygen metabolites required post-CA. With multifactorial roles for maintaining homeostasis, such as acting as an energy substrate, maintaining membrane integrity, and functioning in inter- and intra-cellular signaling, decreased levels of LPC post-CA disrupts the various physiologic responsibilities resulting in profound systemic effects causing cellular and organ system injury. In this analysis, 1) phospholipid screening using HPLS-MS on plasma samples obtained from asphyxial-CA rats and human CA patients shows that LPC significantly decreases post-CA, especially during the reperfusion phase, and is strongly correlated with the duration of preceding CA and poor neurological/survival outcomes, and 2) individual supplementation of three species of LPC (LPC 18:0, LPC 18:1, and LPC 22:6) following resuscitation after 10 and 12 min rat CA helps improve survival and brain function as compared with vehicle. Overall, our study highlights that LPC is an essential, non-oxygen metabolite that is necessary to help promote survival after CA in rats that has therapeutic potential for human translation.