Previous studies have reported that Post-Cardiac arrest (PCA) treatments including targeted temperature management (TTM), coronary reperfusion therapy (CRT), and extracorporeal membrane oxygenation (ECMO) are time-sensitive; however, there are no reports of the clinical outcomes of PCA treatment according to the scene time interval (STI). Our study aimed to investigated the clinical outcomes of PCA treatment according to the STI.

We used a Korean nationwide OHCA cohort database from January 2017 to December 2020. The inclusion criteria were all adult OHCA patients with a presumed cardiac etiology, bystander-witnessed arrest, and prehospital return of spontaneous circulation (ROSC). The outcomes were survival to discharge and good neurological recovery. The main exposure of interest was PCA treatment. We compared the outcomes using multivariable logistic regression, and interaction terms were included in the final model to assess whether the STI modified the effect of PCA treatment on clinical outcomes of OHCA.

TTM and CRT were associated with high survival to discharge and good neurological recovery. In the interaction analysis, ECMO had an interaction effect with the STI on a good CPC among patients with OHCA [short STI (0 to 11 min) (1.16 (0.77—1.75)), middle STI (12 to 15 min) (0.66 (0.41—1.06)), and long STI (16 to 30 min) (0.59 (0.40—0.88)) (p for interaction <0.05)].

In adult bystander-witnessed patients with OHCA with prehospital ROSC, an STI of >16 min was a risk factor for poor neurological outcome in those patients who underwent ECMO.