Association between bystander automated external defibrillator use and survival in witnessed out-of-hospital cardiac arrest: A nationwide observational study in South Korea.

AIM: Sudden cardiac arrest is a global health issue, with out-of-hospital cardiac arrest (OHCA) posing a major challenge. Bystander cardiopulmonary resuscitation (CPR) and automated external defibrillators (AEDs) improve survival and neurological outcomes. However, their actual usage involves numerous constraints. Therefore, to determine the association between bystander AED use and survival of patients with OHCA, we analyzed South Korea's national OHCA database.

METHODS: This retrospective study included cases from the Korea Disease Control and Prevention Agency's Out-of-Hospital Cardiac Arrest Surveillance database from January 2016 to December 2021. Adult OHCA cases treated with bystander intervention were categorized into two groups, CPR with AEDs and without AEDs. Propensity score matching was employed to control for confounders and analyze bystander AED use's impact on survival to discharge and neurological outcomes.

RESULTS: Of 182,508 OHCA cases, 35,840 met the inclusion criteria, with 234 (0.7%) receiving bystander CPR with AEDs. The survival rate to discharge in the AED and non-AED group was 46.6% and 23.0%, respectively. However, after adjusting for potential confounders, bystander AED use did not significantly affect survival to discharge (adjusted odds ratio [aOR] 1.01, 95% confidence interval [CI] 0.70-1.44) or favorable neurological outcomes (aOR 1.08, 95% CI 0.99-1.18).

CONCLUSION: Survival to discharge or favorable neurological outcomes of patients with OHCA managed using bystander-applied AEDs and those without showed no significant difference. Factors such as AED accessibility and bystander preparedness influence the impact of bystander AED use. Further research should optimize AED deployment and usage strategies to enhance patient survival rate.