Abstract 4363608: Reversal of Decline in Premature Cardiac Arrest Mortality: Demographic and Regional Trends in the United States, 1999–2021

Background: Premature cardiac arrest (CA) is a major cause of death under 65. While declines in CA-related mortality have been observed, national, demographic, and regional trends for premature CA-related mortality remain unexplored. Aims: To evaluate national time trends and demographic and regional disparities in premature CA-related mortality in the United States from 1999 to 2021. Methods: CDC WONDER Multiple Cause-of-Death data was used to identify deaths with CA as an underlying or contributing cause (ICD-10 I46.0, I46.1, I46.9). Age-adjusted mortality rates (AAMRs) per 100,000 and annual percent changes (APCs) with 95% confidence intervals (CIs) were estimated using Joinpoint regression, stratified by sex, race, urbanization, and Census region. Reversal percentages were calculated as the ratio of post-inflection increase to prior decline. Results: Between 1999–2021, there were 1,740,130 premature CA-related deaths that occurred in the US. AAMRs declined from 36.5 in 1999 to 29.9 in 2012 (APC: –3.3% [1999–2002]; –0.9% [2002–2012]), then rose to 44.2 in 2021 (+2.6% [2012–2015]; +0.4% [2015–2019]; +18.0% [2019–2021]). The increase (14.3 [95% CI: 14.0–14.6]) exceeded the prior decline (6.6 [95% CI: 6.3–6.9]), yielding a 216.7% reversal. Males had higher AAMRs than females, rising from 45.0 to 54.7 (reversal: 216.9%) vs. 23.1 to 33.8 (reversal: 201.9%). Non-Hispanic (NH) Black individuals had the highest AAMR in 2021 (79.6) after an initial decline (–3.6% [2006–2011]) and sharp rise (+31.9% [2019–2021]). Hispanic individuals declined through 2011 (–2.4%) then rose, reaching 44.7; NH Whites had modest early declines, followed by a rise to 38.1. Rural AAMRs were higher than urban throughout. In 2020, rural areas reached 38.5 vs. 36.9 in urban areas. Rural mortality declined (–0.8% [1999–2008]) then rose (+2.3% [2008–2020]); urban declined through 2011 (–1.3%) and rose after 2018 (+6.7%). In 2021, the South had the highest AAMR (50.9), followed by the West (49.6), Midwest (42.9), and Northeast (35.3). All regions showed reversals with the steepest being in the West (535.7%) and lowest in the Northeast (109.8%). Conclusion: The reversal in premature CA-related mortality signals a serious public health setback. Mortality remained highest among males, NH Black individuals, rural populations, and the South and West regions of the US. The sharp, unequal rise highlights the need for equity-focused strategies in prevention, intervention, and emergency care.