Evaluation of Sudden Cardiac Arrest by Race/Ethnicity Among Residents of Ventura County, California, 2015-2020

Importance: Sudden cardiac arrest (SCA) is a major public health problem. Owing to a lack of population-based studies in multiracial/multiethnic communities, little information is available regarding race/ethnicity-specific epidemiologic factors of SCA. Objective: To evaluate the association of race/ethnicity with burden, outcomes, and clinical profile of individuals experiencing SCA. Design, Setting, and Participants: A 5-year prospective, population-based cohort study of out-of-hospital SCA was conducted from February 1, 2015, to January 31, 2020, among residents of Ventura County, California (2018 population, 848 112: non-Hispanic White White, 45.8%; Hispanic/Latino Hispanic, 42.4%; Asian, 7.3%; and Black, 1.7% individuals). All individuals with out-of-hospital SCA of likely cardiac cause and resuscitation attempted by emergency medical services were included. Exposures: Data on circumstances and outcomes of SCA from prehospital emergency medical services records and data on demographics and pre-SCA clinical history from detailed archived medical records, death certificates, and autopsies. Main Outcomes and Measures: Annual age-adjusted SCA incidence by race and ethnicity and SCA circumstances and outcomes by ethnicity. Clinical profile (cardiovascular risk factors, comorbidity burden, and cardiac history) by ethnicity, overall, and stratified by sex. Results: A total of 1624 patients with SCA were identified (1059 65.2% men; mean SD age, 70.9 16.1 years). Race/ethnicity data were available for 1542 (95.0%) individuals, of whom 1022 (66.3%) were White, 381 (24.7%) were Hispanic, 86 (5.6%) were Asian, 31 (2.0%) were Black, and 22 (1.4%) were other race/ethnicity. Annual age-adjusted SCA rates per 100 000 residents of Ventura County were similar in White (37.5; 95% CI, 35.2-39.9), Hispanic (37.6; 95% CI, 33.7-41.5; P = .97 vs White), and Black (48.0; 95% CI, 30.8-65.2; P = .18 vs White) individuals, and lower in the Asian population (25.5; 95% CI, 20.1-30.9; P = .006 vs White). Survival to hospital discharge following SCA was similar in the Asian (11.8%), Hispanic (13.9%), and non-Hispanic White (13.0%) (P = .69) populations. Compared with White individuals, Hispanic and Asian individuals were more likely to have hypertension (White, 614 76.3%; Hispanic, 239 79.1%; Asian, 57 89.1%), diabetes (White, 287 35.7%; Hispanic, 178 58.9%; Asian, 37 57.8%), and chronic kidney disease (White, 231 29.0%; Hispanic, 123 40.7%; Asian, 33 51.6%) before SCA. Hispanic individuals were also more likely than White individuals to have hyperlipidemia (White, 380 47.2%; Hispanic, 165 54.6%) and history of stroke (White, 107 13.3%; Hispanic, 55 18.2%), but less likely to have a history of atrial fibrillation (White, 251 31.2%; Hispanic, 59 19.5%). Conclusions and Relevance: The results of this study suggest that the burden of SCA was similar in Hispanic and White individuals and lower in Asian individuals. The Asian and Hispanic populations had shared SCA risk factors, which were different from those of the White population. These findings underscore the need for an improved understanding of race/ethnicity-specific differences in SCA risk.