Prognostic factors for out-of-hospital cardiac arrest patients with prolonged low-flow time undergoing extracorporeal cardiopulmonary resuscitation.

Background: This study aimed to examine factors associated with favourable neurological outcomes in out-of-hospital cardiac arrest (OHCA) patients with low-flow time (LFT) exceeding 60 minutes following extracorporeal cardiopulmonary resuscitation (ECPR).

Methods: This was a secondary analysis of the SAVE-J II study, a retrospective, multicentre, registry study involving 36 participating institutions in Japan. OHCA patients ≥18 years old who underwent ECPR in Japan between January, 2013 and December, 2018 were registered. This study selected the non-hypothermic patients with LFT ≥ 60 minutes. The primary outcome was a favourable neurological outcome (cerebral performance categories 1-2). Multivariable logistic regression analyses were performed to assess the factors associated with a favourable neurological outcome.

Results: In total, 708 patients met the inclusion criteria, with favourable neurological outcomes at hospital discharge in 71 cases (10.0%). Age, shockable rhythm on hospital arrival, signs of life (SOLs) on hospital arrival, and transient return of spontaneous circulation (ROSC) were significantly associated with a favourable neurological outcome.

Conclusions: Approximately 10% of OHCA patients who underwent ECPR with LFT ≥ 60 minutes had favourable neurological outcomes. ECPR for non-hypothermic OHCA patients might be considered even with prolonged LFT based on age, shockable rhythm on hospital arrival, SOLs on hospital arrival, and presence of transient ROSC before ECMO initiation.