Extracorporeal cardiopulmonary resuscitation for refractory out-of-hospital cardiac arrest: a systematic review and meta-analysis of randomized clinical trials

IntroductionExtracorporeal cardiopulmonary resuscitation (ECPR) is currently recommended as a rescue therapy for selected patients in refractory out-of-hospital cardiac arrest (OHCA). However, there is conflicting evidence regarding its effect on survival and neurological outcomes. We conducted a systematic review and meta-analysis of randomized clinical trials (RCTs) to evaluate whether ECPR is superior to standard CPR in refractory OHCA.MethodsWe performed a systematic search of electronic databases (PubMed, CENTRAL, and Scopus) until March 2023. Studies were eligible if they a) were RCTs, and b) compared ECPR vs. standard CPR for OHCA. Outcomes were defined as survival with a favorable neurological status (cerebral performance category 1 or 2) at both the shortest follow-up and at 6 months, and in-hospital mortality. Meta-analyses using a random-effects model were undertaken.ResultsThree RCTs, with a total of four hundred and eighteen patients, were included. Compared with standard CPR, ECPR was associated with a non-statistically significant higher rate of survival with a favorable neurological outcome at the shortest follow-up (26.4% vs. 17.2%; RR 1.47 [95% CI 0.91-2.40], P = 0.12) and at 6 months (28.3% vs. 18.6%; RR 1.48 [95% CI 0.88-2.49], P = 0.14). The mean absolute rate of in-hospital mortality was not significantly lower in the ECPR group (RR 0.89 [95% CI 0.74-1.07], P = 0.23).ConclusionECPR was not associated with a significant improvement in survival with favorable neurologic outcomes in refractory OHCA patients. Nevertheless, these results constitute the rationale for a well-conducted, large-scale RCT, aiming to clarify the effectiveness of ECPR compared to standard CPR.