Abstract 263: Disparities in Antiarrhythmic Practices for Out-of-Hospital Cardiac Arrest

Abstract

Background: Antiarrhythmics are an important treatment for out-of-hospital cardiac arrest (OHCA) with a shockable rhythm, but little is known about racial and ethnic disparities in antiarrhythmic administration practices. Objective: This study aims to investigate the association between community race/ethnicity and antiarrhythmic administration for OHCA. Hypothesis: OHCAs in minority communities receive antiarrhythmics less often and with a longer delay. Methods: We conducted a retrospective study of a national prehospital database, NEMSIS, linked to Census data. We included all cardiac arrests from 2018-2021 with a shockable rhythm. We stratified patients based on majority (>50%) zip code race/ethnicity (non-Hispanic White (White), non-Hispanic Black (Black), and Hispanic). For patients with a shockable rhythm at any point, we performed a mixed logistic regression model evaluating the association ZIP code race/ethnicity to administration of antiarrhythmic medication. We modeled EMS agency as a random intercept and adjusted for possible confounders. For patients with an initial shockable rhythm, we compared the time from EMS dispatch to first antiarrhythmic administration between strata. Results: Of 763,944 cardiac arrests, 203,816 had an initial shockable rhythm at any point during the encounter and 111,778 had an initial shockable rhythm. For patients with a shockable rhythm at any point, the median age was 65 (IQR 54-75), 68.5% were male, 65.9% occurred in a private residence, and 67.1% were bystander witnessed. Majority White (33.9%) received antiarrhythmics at a higher rate than majority Black (31.8%; aOR 0.89, 95% CI 0.85-0.94) and majority Hispanic (28.1%; aOR 0.89, 95% CI 0.84-0.94). For patients with an initial shockable rhythm, the time to antiarrhythmic for White (mean 22.2, SD 10.8, median 19.8 minutes, IQR 15-26.6 minute), was lower than Black (mean 22.6, SD 10.7, median 20.3 minutes, IQR 16.1-26.5 minutes, p=0.02) but higher than Hispanic (mean 20.3, SD 9.7, median 18.1 minutes, IQR 14.3-23.6 minutes, p<0.01). Conclusion: While antiarrhythmic administration rate was lower for minority communities and time to antiarrhythmic was higher for Black OHCAs, time to antiarrhythmic administration was lower for Hispanic OHCAs.