BACKGROUND: We aimed to estimate the effect of extracorporeal cardiopulmonary resuscitation (ECPR) on neurological outcome and mortality, when compared to conventional cardiopulmonary resuscitation (CCPR), using an individual patient data meta-analysis (IPDMA). METHODS: A systematic literature search was performed up to the 20th of October 2022 in the PubMed, EMBASE and CENTRAL databases. For observational studies with unmatched populations, a propensity score including age, location of arrest and initial rhythm was used to match ECPR and CCPR patients in a 1:1 ratio. The primary and secondary outcomes were unfavorable neurological outcome (Cerebral Performance Category of 3-5) and mortality, respectively, which were both collected at different time-points. RESULTS: Data from 17 studies, including 2064 matched cardiac arrest (CA) patients (1031 ECPR and 1033 CCPR cases) were included. In comparison to CCPR, ECPR was associated with a decreased odds of unfavorable neurological outcome (847, 82.2% vs. 897, 86.8% - OR 0.68 [95%CI 0.53-0.87]; p = 0.002) and death (803, 77.9% vs. 860, 83.3% - OR 0.68 [95%CI 0.54-0.86]; p = 0.001). These results were consistent across most of the prespecified subgroups. Moreover, the odds of both unfavorable neurological outcome and mortality were significantly influenced by initial rhythm, cause of arrest and combinations of lactate levels on admission and duration of resuscitation. CONCLUSIONS: This IPDMA showed that ECPR was associated with significantly lower rates of unfavorable neurological outcome and mortality in refractory CA. The overall effect could be influenced by CA characteristics and the severity of the initial injury.
