Effect of intra-arrest transport, extracorporeal cardiopulmonary resuscitation and immediate invasive assessment in refractory out-of-hospital cardiac arrest: a long-term follow-up of the Prague OHCA trial

Abstract

Background: Randomized data evaluating the impact of the extracorporeal cardiopulmonary resuscitation (ECPR) approach on long-term clinical outcomes in patients with refractory out-of-hospital cardiac arrest (OHCA) are lacking. The objective of this follow-up study was to assess the long-term clinical outcomes of the ECPR-based versus CCPR approach.

Methods: The Prague OHCA trial was a single-center, randomized, open-label trial. Patients with witnessed refractory OHCA of presumed cardiac origin, without return of spontaneous circulation, were randomized during ongoing resuscitation on scene to conventional CPR (CCPR) or an ECPR-based approach (intra-arrest transport, ECPR if ROSC is not achieved prehospital and immediate invasive assessment).

Results: From March 2013 to October 2020, 264 patients were randomized during ongoing resuscitation on scene, and 256 patients were enrolled. Long-term follow-up was performed 5.3 (interquartile range 3.8-7.2) years after initial randomization and was completed in 255 of 256 patients (99.6%). In total, 34/123 (27.6%) patients in the ECPR-based group and 26/132 (19.7%) in the CCPR group were alive (log-rank P = 0.01). There were no significant differences between the treatment groups in the neurological outcome, survival after hospital discharge, risk of hospitalization, major cardiovascular events and quality of life. Of long-term survivors, 1/34 (2.9%) in the ECPR-based arm and 1/26 (3.8%) in the CCPR arm had poor neurological outcome (both patients had a cerebral performance category score of 3).

Conclusions: Among patients with refractory OHCA, the ECPR-based approach significantly improved long-term survival. There were no differences in the neurological outcome, major cardiovascular events and quality of life between the groups, but the trial was possibly underpowered to detect a clinically relevant difference in these outcomes. Trial registration ClinicalTrials.gov Identifier: NCT01511666, Registered 19 January 2012.

Keywords: Extracorporeal cardiopulmonary resuscitation; Extracorporeal membrane oxygenation; Long-term; Out-of-hospital cardiac arrest; Quality of life.

Fig. 1

Trial profile. CCPR conventional cardiopulmonary resuscitation, CPR cardiopulmonary resuscitation, ECPR extracorporeal cardiopulmonary resuscitation

Fig. 2

A Kaplan–Meier plot showing cumulative patient survival from index cardiac arrest to last follow-up for the intention-to-treat population. CCPR conventional cardiopulmonary resuscitation, ECPR extracorporeal cardiopulmonary resuscitation. B Kaplan–Meier plot showing cumulative patient survival from index cardiac arrest to last follow-up for the per-protocol population. *The per-protocol analysis is a post hoc analysis that includes only those patients who completed the treatment originally allocated (excluding all crossovers, 20/256 patients (7.8%) were crossed over, 11 crossovers from the CCPR group to the ECPR-based group and 9 from the ECPR-based group to the CCPR group). CCPR conventional cardiopulmonary resuscitation, ECPR extracorporeal cardiopulmonary resuscitation. C Kaplan–Meier plot showing cumulative patient survival from index cardiac arrest to last follow-up for the as-treated population. *The as-treated analysis is a post hoc analysis that pooled all randomized patients according to their treatment allocation after the accepted crossover (20/256 patients (7.8%) were crossed over, 11 crossovers from the CCPR group to the ECPR-based group and 9 from the ECPR-based group to the CCPR group). CCPR conventional cardiopulmonary resuscitation, ECPR extracorporeal cardiopulmonary resuscitation

Fig. 3

Neurological outcome results assessed by CPC at 30-day (A), 180-day (B) and the last-follow-up (median 5.3 years, IQR 3.8–7.2 years) (C) for CCPR group and ECPR-based group. CCPR conventional cardiopulmonary resuscitation, CPC cerebral performance category, ECPR extracorporeal cardiopulmonary resuscitation