Abstract 4135335: A randomized trial of expedited intra-arrest transfer versus more extended on-scene resuscitation for refractory out of hospital cardiac arrest: the EVIDENCE Study

Background: Refractory out-of-hospital cardiac arrest (OHCA) has poor outcomes. The benefit of expedited intra-arrest transport with ongoing resuscitation versus more extended on-scene resuscitation for refractory OHCA is not clear. Methods: In this Phase III, multi-center (15 hospitals), randomized, controlled trial conducted in Sydney, Australia, we assigned patients with refractory out-of-hospital cardiac arrest to receive either expedited intra-arrest transport, with mechanical cardiopulmonary resuscitation, to a cardiac catherization-capable hospital for coronary angiography and, where available, extracorporeal membrane oxygenation (ECMO) cardiopulmonary resuscitation (ECPR) or more extended on-scene conventional CPR (advanced cardiac life support). Eligible patients were between 18 and 70 years of age, had received bystander CPR, initial rhythm VT/VF/PEA, and did not have a return of spontaneous circulation after 15 minutes of CPR, or three rounds of resuscitation. The primary outcome was survival with a favorable neurologic outcome, defined as a Cerebral Performance Category score of 1 or 2 at hospital discharge. Analyses were performed on an intention-to-treat basis. Results: One hundred and ninety-seven (197) eligible patients were randomized (median age, 57.0 years; 77 [81%] men), 149 VT/VF (76%). Ninety-five were assigned to receive expedited transfer and 102 to receive conventional CPR. Ten patients in the expedited arms and 6 patients in the conventional arm received ECPR at hospital. At hospital discharge, 15 patients (14.7%) in the expedited transfer group (median on scene time 26 mins) were alive with a favorable neurologic outcome, as compared with 15 patients (15.8%) (median on-scene time 36 minutes). This treatment difference was small and statistically insignificant (risk difference -1.1% [95% CI: -12.2% to 10.0%]), adjusted relative risk 0.95 [p=0.87, 95% CI: 0.50 to 1.8]. Conclusions: Among patients with refractory out-of-hospital cardiac arrest, expedited intra-arrest transport did not significantly improve survival with neurologically favorable outcome at discharge compared with more extended on-scene resuscitation. However, clinically relevant differences could still be consistent with our results.