Trends in Overdose-Related Out-of-Hospital Cardiac Arrests in Arizona.

AIM: Opioid overdose mortality has increased in North America; however, recent regional trends in the proportion of treated overdose-related out-of-hospital cardiac arrests (OD-OHCA) compared to out-of-hospital cardiac arrests of presumed cardiac etiology (C-OHCA) are largely unknown. Our aim is to assess trends in the prevalence and outcomes of OD-OHCA compared to C-OHCA in Arizona.

METHODS: Statewide, observational study utilizing an Utstein-style database with EMS-first care reports linked with hospital records, and vital statistics data from 2010-2015.

RESULTS: There were 21,658 OHCA during the study period. After excluding non-C-OHCA, non-OD-OHCA, and cases missing outcome data, 18,562 cases remained. Of these remaining cases, 17,591 (94.8%) were C-OHCA and 971 (5.2%) were OD-OHCA. There was a significant increase in the proportion of OD-OHCA from 2010, 4.7% (95% CI: 3.9-5.5) to 2015, 6.6% (95% CI: 5.8-7.5). Mean age for OD-OHCA was 38 years compared to 66 years for C-OHCA, (p < 0.0001). Initial shockable rhythm was present in 7.1% of OD-OHCA vs. 22.6% of C-OHCA (p < 0.0001). Overall survival to discharge in the OD-OHCA group was 18.6% vs. 11.9% in C-OHCA (p < 0.0001). After risk adjustment, we found an aOR of 2.1 (95% CI: 1.8-2.6) for survival in OD-OHCA compared to C-OHCA.

CONCLUSION: There has been a significant increase in the proportion of OD-OHCA in Arizona between 2010-2015. OD-OHCA patients were younger, were less likely to present with a shockable rhythm, and more likely to survive than patients with C-OHCA. These data should be considered in prevention and treatment efforts.