Overcoming Limitations in Out-of-Hospital Cardiac Arrest Extracorporeal Cardiopulmonary Resuscitation: Optimizing Assessment and Patient Selection for Future Clinical Trials

In the pre-hospital setting, the efficacy and superiority analysis of the extracorporeal cardiopulmonary resuscitation (ECPR) technique presents significant methodological challenges. While ECPR has shown promising results in improving patient outcomes in cases of in-hospital cardiac arrest (IHCA), recent meta-analyses showed no significant disparities in mortality between ECPR and conventional CPR among out-of-hospital cardiac arrest (OHCA) patients. Furthermore, ECPR failed to demonstrate a conclusive advantage concerning neurological outcomes in this patient population. As pointed out previously, the observed results reflect the substantial heterogeneity in confounders due to patient selection, cost-effectiveness, and on-ground technical and logistical challenges. Such inhomogeneity may negate the potential benefits of extracorporeal cardiopulmonary resuscitation (ECPR) by increasing the risk of brain injury and organ failure. Given these findings, we agree that more studies are needed to elucidate appropriate patient populations and timing of ECPR among OHCA patients. However, we would like to highlight additional methodological aspects that need to be accounted for when designing future clinical trials.