Factors mediating community race and ethnicity differences in initial shockable rhythm for out-of-hospital cardiac...

Out-of-hospital cardiac arrest (OHCA) patients from minoritized communities have lower rates of initial shockable rhythm, which is linked to favorable outcomes. We sought to evaluate the importance of initial shockable rhythm on OHCA outcomes and factors that mediate differences in initial shockable rhythm.

We performed a retrospective study of the 2013-2022 Texas Cardiac Arrest Registry to Enhance Survival (TX-CARES). Using census tract data, we stratified OHCAs into majority race/ethnicity communities: >50% White, >50% Black, and >50% Hispanic/Latino. We compared logistic regression models between community race/ethnicity and OHCA outcome: (1) unadjusted, (2) adjusting for bystander CPR (bCPR), and (3) adjusting for initial rhythm. Using structural equation modeling, we performed mediation analyses between community race/ethnicity, OHCA characteristics, and initial shockable rhythm.

We included 22,730 OHCAs from majority White (21.1% initial shockable rhythm), 4,749 from majority Black (15.3% shockable), and 16,054 majority Hispanic/Latino (16.1% shockable) communities. Odds of favorable neurologic outcome were lower for majority Black (0.4 [0.3-0.5]) and Hispanic/Latino (0.6 [0.6-0.7]). While adjusting for bCPR minimally changed outcome odds, adjusting for shockable rhythm increased odds for Black (0.5 [0.4-0.5]) and Hispanic/Latino (0.7 [0.6-0.8]) communities. On mediation analysis for majority Black, the top mediators of initial shockable rhythm were public location (14.6%), bystander witnessed OHCA (11.6%), and female gender (5.7%). The top mediators for majority Hispanic/Latino were bystander-witnessed OHCA (10.2%), public location (3.52%), and bystander CPR (3.49%), CONCLUSION: Bystander-witnessed OHCA and public location were the largest mediators of shockable rhythm for OHCAs from minoritized communities.