Extracorporeal cardiopulmonary resuscitation with temperature management could improve the neurological outcomes of out-of-hospital cardiac arrest: a retrospective analysis of a nationwide multicenter observational study in Japan

BACKGROUND: Target temperature management (TTM) is an effective component of treating out-of-hospital cardiac arrest (OHCA) after return of spontaneous circulation in conventional cardiopulmonary resuscitation. However, therapeutic hypothermia (32–34 °C TTM) is not recommended based on the results of recent studies. Extracorporeal cardiopulmonary resuscitation (ECPR) with veno-arterial extracorporeal membrane oxygenation is another promising therapy for OHCA, but few studies have examined the effectiveness of ECPR with TTM. Therefore, we hypothesized that ECPR with TTM could have the effectiveness to improve the neurological outcomes for adults following witnessed OHCA, in comparison to ECPR without TTM. METHODS: We performed retrospective subanalyses of the Japanese Association for Acute Medicine OHCA registry. We focused on adults who underwent ECPR for witnessed OHCA. We performed univariate (the Mann–Whitney U test and Fisher’s exact test), multivariable (logistic regression analyses), and propensity score analyses (the inverse probability of the treatment-weighting method) with to compare the neurological outcomes between patients with or without TTM, among all eligible patients, patients with a cardiogenic cause, and patients divided into subgroups according to the interval from collapse to pump start (ICPS) (> 30, > 45, or > 60 min). RESULTS: We analyzed data for 977 patients. Among 471 patients treated with TTM, the target temperature was therapeutic hypothermia in 70%, and the median interval from collapse to target temperature was 249 min. Propensity score analysis showed a positive association between TTM and favorable neurological outcomes in all patients (odds ratio 1.546 [95% confidence interval 1.046–2.286], P = 0.029), and in patients with ICPS of > 30 or > 45 min, but not in those with ICPS of > 60 min. The propensity score analysis also showed a positive association between TTM and favorable neurological outcomes in patients with a cardiogenic cause (odds ratio 1.655 [95% confidence interval 1.096–2.500], P = 0.017), including in all ICPS subgroups (> 30, > 45, and > 60 min). CONCLUSION: Within patients who underwent ECPR following OHCA, ECPR with TTM could show the potential of improvement in the neurological outcomes, compared to ECPR without TTM.