Effect of Cardiac Arrest Center Protocol Implementation on Survival After Nontraumatic Out‐of‐Hospital Cardiac Arrest

Evidence on the effect of treatment at a cardiac arrest center (CAC) on clinical outcomes is incomplete and conflicting. The aim was to evaluate the effect of treatment at a CAC on survival after out-of-hospital cardiac arrest. For this retrospective cohort study, data from all 790 consecutive patients admitted to our center from January 2018 to May 2023 after nontraumatic out-of hospital cardiac arrest were analyzed. All CAC protocols were completely introduced in October 2020. The primary end point was death or unfavorable neurological outcome (cerebral performance category 3-5) at 90 days. Patients were stratified by Cardiac Arrest Survival Score. We compared 432 patients (54.7%) managed before to 358 patients (45.3%) after full CAC implementation. Their median age was 68 (interquartile range, 56-78) years before and 67 (interquartile range, 55-78) thereafter. Cardiac Arrest Survival Score was significantly higher before CAC introduction (median, 28.9% [interquartile range, 8.78-59.9]) than after (6.9% [interquartile range, 1.1-23.3]; P<0.01). The incidence of the primary end point did not differ significantly between the 2 periods in multivariable analysis (82.9% versus 84.3%; hazard ratio [HR], 0.95 [95% CI, 0.74-1.23]; P=0.7). However, there was significant statistical interaction between CAC implementation and Cardiac Arrest Survival Score (P<0.048). The risk of death or unfavorable neurological outcome at 90 days was significantly lower after than before CAC implementation (HR, 0.73 [95% CI, 0.54-0.98]; P=0.04) in patients with Cardiac Arrest Survival Score above the overall median of 15.5%. Coordinated and specialized treatment in a certified CAC may not impact outcomes in patients with low survival probability after nontraumatic out-of-hospital cardiac arrest, but appears to improve survival in patients with intermediate and high survival probability.