In-hospital extracorporeal cardiopulmonary resuscitation for patients with out-of-hospital cardiac arrest: an analysis by time-dependent propensity score matching using a nationwide database in Japan

Abstract

Background Extracorporeal cardiopulmonary resuscitation (ECPR) has been proposed as a rescue therapy for patients with refractory cardiac arrest. This study aimed to evaluate the association between ECPR and clinical outcomes among patients with out-of-hospital cardiac arrest (OHCA) using risk-set matching with a time-dependent propensity score. Methods This was a secondary analysis of the JAAM-OHCA registry data, a nationwide multicenter prospective study of patients with OHCA, from June 2014 and December 2019, that included adults (≥ 18 years) with OHCA. Initial cardiac rhythm was classified as shockable and non-shockable. Patients who received ECPR were sequentially matched with the control, within the same time (minutes) based on time-dependent propensity scores calculated from potential confounders. The odds ratios with 95% confidence intervals (CI) for 30-day survival and 30-day favorable neurological outcomes were estimated for ECPR cases using a conditional logistic model. Results Of 57,754 patients in the JAAM-OHCA registry, we selected 1826 patients with an initial shockable rhythm (treated with ECPR, n = 913 and control, n = 913) and a cohort of 740 patients with an initial non-shockable rhythm (treated with ECPR, n = 370 and control, n = 370). In these matched cohorts, the odds ratio for 30-day survival in the ECPR group was 1.76 [95%CI 1.38–2.25] for shockable rhythm and 5.37 [95%CI 2.53–11.43] for non-shockable rhythm, compared to controls. For favorable neurological outcomes, the odds ratio in the ECPR group was 1.11 [95%CI 0.82–1.49] for shockable rhythm and 4.25 [95%CI 1.43–12.63] for non-shockable rhythm, compared to controls. Conclusion ECPR was associated with increased 30-day survival in patients with OHCA with initial shockable and even non-shockable rhythms. Further research is warranted to investigate the reproducibility of the results and who is the best candidate for ECPR. Graphical Abstract

Extracorporeal cardiopulmonary resuscitation versus conventional CPR in cardiac arrest: an updated meta-analysis and trial sequential analysis

“…In our previously published report, we discussed differing conclusions between the three RCTs examining this topic and proposed that varying times to cannulation between these studies might explain their differing results, with the RCT having the shortest time to cannulation having the greatest benefit seen in ECPR. We posit that this same variable may also explain the shift in these updated results, particularly with reference to the inclusion of Okada et al [8]. Okada and colleagues were able to achieve extremely fast time to ECPR cannulation, with a median time of under 30 min in both shockable and non-shockable cohorts, which corroborates with the findings from our prior meta-regression that mortality increases with low-flow time (HR [hazard ratio] per min: 1.01, 95% CI 1.00-1.01).…”

“…Although both new studies had large sample sizes, it was Okada et al [ 8 ] which included both shockable and non-shockable cohorts that primarily led to improvements in precision and generalisability of results, and an improved estimate in the OHCA cohort. The other new study, Choi et al [ 9 ], did not see any significant differences in mortality with ECPR, with results being imprecise.…”

“…Further details on the original methodology, along with their references, can be found in Additional file 1 : Original Methods and References for Original Methods. As both shockable and non-shockable cohorts in Okada et al [ 8 ] were matched separately, we have included these cohorts separately in this updated analysis. We used p-values of less than 0.05 as the threshold for statistical significance.…”

“…The publication of a new propensity score matched study by Okada et al [ 8 ] evaluating ECPR in over 2000 patients with OHCA is a timely addition to the literature, along with a similar study by Choi et al [ 9 ]. We believe that the publication of these new studies stands to enhance our understanding of this topic.…”