Prognosis by aetiologies in extracorporeal cardiopulmonary resuscitation for out-of- hospital cardiac arrest: a retrospective multicentre cohort study

Abstract

Background The relative contributions of various factors to patient outcomes are essential for optimal patient selection for extracorporeal cardiopulmonary resuscitation (ECPR) in out-of-hospital cardiac arrest (OHCA). However, evidence of these aetiologies is limited. Therefore, in this study, we investigated the prognosis of the aetiologies of ECPR for OHCA.Methods This retrospective multicentre registry study involved 36 institutions in Japan and included adult patients with out-of-hospital cardiac arrest who underwent ECPR between January 2013 and December 2018. We assessed neurological outcomes at discharge based on aetiology using the cerebral performance category (CPC) score. The primary outcome was a favourable neurological outcome (CPC 1–2) at hospital discharge. We performed a multivariable logistic regression analysis to determine favourable neurological outcomes according to the aetiology of cardiac arrest.Results We identified 2,140 eligible patients, of whom 1,988 (92.9%) had cardiac arrest due to medical causes, and 152 (7.1%) had cardiac arrest due to non-medical causes. Most patients (1,663) were presumed to have cardiac causes. The proportion of patients with favourable neurological outcomes at hospital discharge was significantly higher in the non-medical-cause group than in the medical-cause group (26.3% vs. 14.0%, p < 0.001). Multivariable logistic regression analysis showed that accidental hypothermia (adjusted odds ratio [OR] = 6.89; 95% confidence interval [CI] = 4.01–11.85, p < 0.001) and pulmonary embolism (adjusted OR = 2.35; 95% CI = 1.14–4.85, p = 0.020) were associated with a significantly higher rate of favourable outcome than the presumed cardiac causes.Conclusions In this retrospective multicentre cohort study, accidental hypothermia and pulmonary embolism were associated with more favourable neurologic outcomes than the presumed cardiac causes. Prospective studies should be conducted to validate the findings of the present study.