Predictive factors associated with favourable neurological outcomes after extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest: a retrospective multicentre cohort study

Abstract Background: Knowledge of the relative contributions of various factors to patient outcomes is crucial for optimal patient selection for extracorporeal cardiopulmonary resuscitation (ECPR) after out-of-hospital cardiac arrest (OHCA). However, evidence pertaining to their effects on neurological outcomes is limited. In this study, we investigated the predictive factors associated with favourable neurological outcomes after ECPR for OHCA. Methods: We performed a secondary analysis of the SAVE-J II data, a retrospective multicentre registry study involving 36 participating institutions in Japan. Between 2013 and 2018, 2157 patients with OHCA who underwent ECPR were enrolled in SAVE-J II. Adult patients (aged ≥ 18 years) with OHCA, who underwent ECPR before admission to the intensive care unit (ICU), were included in our secondary analysis. Our primary outcome was a favourable neurological outcome at hospital discharge, defined as a Cerebral Performance Category (CPC) score of 1 or 2. We used a multivariate logistic regression model to examine the association between predictive factors measured at the incident scene or upon hospital arrival, and favourable neurological outcomes. Results: A total of 1823 patients met study inclusion criteria. Multivariable analysis revealed that shockable rhythm at the scene of the OHCA (odds ratio (OR), 2.72; 95% confidence interval (CI), 1.43−5.38) and upon hospital arrival (OR, 2.56; 95% CI, 1.57−4.26), as well as unsustained return of spontaneous circulation (ROSC) (OR, 1.94; 95% CI, 1.02−3.61), gasping (OR, 4.67; 95% CI, 2.80−7.82), and pupillary reflex on arrival (OR, 3.06; 95% CI, 1.82−5.14) were significantly associated with favourable neurological outcomes. Conclusions: This retrospective multicentre cohort study suggests that shockable rhythm, unsustained ROSC, gasping, and pupillary reflex were associated with particularly favourable neurological outcomes in patients with OHCA undergoing ECPR.