Endoplasmic reticulum stress markers are of no value in predicting cardiopulmonary resuscitation success and survival in out-of hospital cardiac arrest: A nested case-control study

The purpose of this study was to determine the value of the endoplasmic reticulum (ER) stress markers glucose-regulated protein 78 (GRP78), C/EBP homologous protein (CHOP) and PERK in predicting the success of cardiopulmonary resuscitation (CPR) or post-CPR survival. Materials and Methods Non-traumatic out-of-hospital CA patients were included in this prospective, nested case-control study. Standard CPR and post-resuscitative care were applied. Levels of ER stress markers were measured at presentation and were investigated to determine whether they might constitute a marker predicting return of spontaneous circulation (ROSC) or sustained ROSC, and of 24-h, and 1 and 3-month survival. Results Fifty-two out of 99 non-traumatic CA patients were enrolled. ROSC was determined at a level of 25%, sustained ROSC at 23%, 24-h survival at 7%, and 1- and 3-month survival at 4.6%. No difference was determined in terms of ER stress markers between patients with and without ROSC or sustained ROSC. Only PERK levels were higher in surviving patients than non-surviving subjects in terms of 24-h survival (p = 0.01). Otherwise, no stress markers differed between surviving and non-surviving patients at any survival time point. Conclusion ER stress markers are of no value in determining establishment of ROSC or sustained ROSC, success of CPR, or survival. Only PERK levels may be valuable in terms of 24-h survival.