b'CARES 2023 Annual ReportResearch HighlightsAutomated External Defibrillator Use After Out-of-Hospital Cardiac Arrest at Recreational FacilitiesAhmed A. Kolkailah MD, MSc and Saket Girotra MD, SM Division of Cardiology, University of Texas Southwestern Medical Center, Dallas, TX, USAOut-of-hospital cardiac arrest (OHCA) during exercise is often due to a ventricular arrhythmia, for which prompt application of an automated external defibrillator (AED) can be lifesaving. Given that proximity to an AED is a major barrier, some states have enacted laws that require athletic facilities to have an AED available on-site. 2-5However, contemporary data on bystander application of AEDs in states that have enacted these laws is lacking. To address this knowledge gap, we used CARES to examine rates of bystander AED application for OHCA at recreational facilities in states with and without laws mandating the presence of AEDs in athletic facilities. 6We included all adult (18 years) OHCA cases that occurred between 2013 and 2021 at a recreational facility in the United States. We excluded OHCA cases that were witnessed by a 911 responder, low volume states (5 cases), and cases from states that changed their law status during the study period. The primary exposure was whether the state in which the arrest occurred passed legislation to mandate an AED at athletic facilities prior to 2013. The primary outcome was bystander AED application following the OHCA, and secondary outcomes included survival to hospital admission and survival to hospital discharge.A total of 4,145 non-traumatic OHCAs occurred at recreational facilities in the 13 states with an AED mandate and 5,145 cases occurred in the 27 states without an AED mandate. The mean age was 56.916.4 years, 85.5% were men, and 54.7% were White. The initial presenting rhythm was shockable in 46.8% of cases, 67.6% of arrests were witnessed by a bystander, and bystander CPR was performed in 61.3% of cases. Most patient and cardiac arrest characteristics were similar between states with and without AED laws; however, states with AED laws had a higher proportion of arrests with a presumed cardiac etiology (79.0% vs. 74.9%) and a lower rate of bystander CPR (57.9% vs. 64.0%). Among states with laws mandating AEDs at athletic facilities, the median rate of bystander AED application was 19.0%, which varied markedly across states (interquartile range [IQR]: 15.1-22.0%, range: 8.6-28.8%). The overall rate of survival to hospital admission was 44.5% (IQR: 39.4-56.9%, range: 36.0-58.6%), and survival to hospital discharge was 31.0% (IQR: 25.2-32.8%, range: 18.9-42.9%). Among states without laws mandating AEDs at athletic facilities, the median rate of bystander AED application was 18.2% (IQR: 13.9-25.0%, range: 7.4-50.0%) (Figure). The overall rate of survival to hospital admission was 45.0%(IQR: 38.4-52.1%, range: 33.3-70.0%), and survival to hospital discharge was 28.4% (IQR: 25.9-37.5%, range: 15.8-50.0%).In this contemporary cohort of OHCA cases at recreational facilities, we found that bystander AED application was remarkably low. Despite nearly half of the cohort (47%) having an initial shockable rhythm, fewer than 1 in 5 victims had an AED applied by a bystander, regardless of the states AED law status. Our findings highlight the need for improving rates of bystander AED application following OHCA that go beyond legislative measures. Efforts to mitigate these sobering findings may include ensuring that AEDs are available on-site with appropriate signage and directions, dispatcher-assisted guidance on their usage, and continued education of the lay public on performing prompt lifesaving interventions such as CPR and appropriate AED use.26 27'