Cardiac Arrest Registry To Enhance Survival Research Articles

Implantable Cardioverter-Defibrillators Among Older Survivors of Out-of-Hospital Cardiac Arrest.

Although current guidelines recommend implantable cardioverter-defibrillator (ICD) placement in survivors of out-of-hospital cardiac arrest, contemporary data on secondary-prevention ICDs in survivors of out-of-hospital cardiac arrest remain limited. Using 2013 to 2019 CARES (Cardiac Arrest Registry to Enhance Survival) linked to Medicare, we identified 3226 patients aged ≥65 years with an initial shockable rhythm who survived to discharge without severe neurological disability. Multivariable hierarchical regression models were used to examine the association between patient variables and ICD placement and quantify hospital variation in ICD implantation. The mean age was 72.2 years, 23.5% were women, 10% were Black individuals, and 4% were Hispanic individuals. Overall, 997 (30.9%) patients received an ICD before discharge, 1266 (39.2%) at 90 days, and 1287 (39.9%) within 6 months. Older age (≥85 years), female sex, history of diabetes, calendar year, and presentation with acute myocardial infarction were associated with lower odds of ICD implantation, but race or ethnicity was not associated with ICD implantation. Among 297 hospitals, the median proportion of survivors receiving ICD at discharge was 28.6% (interquartile range, 20%-50%). The relative odds of ICD implantation varied by 62% across hospitals (median odds ratio, 1.62 [95% CI, 1.38-1.82]) after adjusting for case mix. Fewer than 1 in 3 survivors of out-of-hospital cardiac arrest due to a shockable rhythm received a secondary-prevention ICD before discharge. Although patient variables were associated with ICD implantation, there was no difference by race or ethnicity. Even after adjusting for patient case mix, ICD implantation varied markedly across hospitals.

Emergency Medical Service Agency Practices and Cardiac Arrest Survival

Survival for out-of-hospital cardiac arrest (OHCA) varies widely across emergency medical service (EMS) agencies in the US. However, little is known about which EMS practices are associated with higher agency-level survival. To identify resuscitation practices associated with favorable neurological survival for OHCA at EMS agencies. This cohort study surveyed EMS agencies participating in the Cardiac Arrest Registry to Enhance Survival (CARES) with 10 or more OHCAs annually during January 2015 to December 2019; data analyses were performed from April to October 2023. Survey of resuscitation practices at EMS agencies. Risk-standardized rates of favorable neurological survival for OHCA at each EMS agency were estimated using hierarchical logistic regression. Multivariable linear regression then examined the association of EMS practices with rates of risk-standardized favorable neurological survival. Of 577 eligible EMS agencies, 470 agencies (81.5%) completed the survey. The mean (SD) rate of risk-standardized favorable neurological survival was 8.1% (1.8%). A total of 7 EMS practices across 3 domains (training, cardiopulmonary resuscitation [CPR], and transport) were associated with higher rates of risk-standardized favorable neurological survival. EMS agencies with higher favorable neurological survival rates were more likely to use simulation to assess CPR competency (β = 0.54; P = .05), perform frequent reassessment (at least once every 6 months) of CPR competency in new staff (β = 0.51; P = .04), use full multiperson scenario simulation for ongoing skills training (β = 0.48; P = .01), perform simulation training at least every 6 months (β = 0.63; P < .001), and conduct training in the use of mechanical CPR devices at least once annually (β = 0.43; P = .04). EMS agencies with higher risk-standardized favorable neurological survival were also more likely to use CPR feedback devices (β = 0.58; P = .007) and to transport patients to a designated cardiac arrest or ST-segment elevation myocardial infarction receiving center (β = 0.57; P = .003). Adoption of more than half (≥4) of the 7 practices was more common at EMS agencies in the highest quartile of favorable neurological survival rates (70 of 118 agencies [59.3%]) vs the lowest quartile (42 of 118 agencies [35.6%]) (P < .001). In a national registry for OHCA, 7 practices associated with higher rates of favorable neurological survival were identified at EMS agencies. Given wide variability in neurological survival across EMS agencies, these findings provide initial insights into EMS practices associated with top-performing EMS agencies in OHCA survival. Future studies are needed to validate these findings and identify best practices for EMS agencies.

Prehospital Ground and Helicopter-Based Extracorporeal Cardiopulmonary Resuscitation (ECPR) Reduce Barriers to ECPR: A GIS Model

Introduction Evidence suggests that Extracorporeal Cardiopulmonary Resuscitation (ECPR) can improve survival rates for nontraumatic out-of-hospital cardiac arrest (OHCA). However, when ECPR is indicated over 50% of potential candidates are unable to qualify in the current hospital-based system due to geographic limitations. This study employs a Geographic Information System (GIS) model to estimate the number of ECPR eligible patients within the United States in the current hospital-based system, a prehospital ECPR ground-based system, and a prehospital ECPR Helicopter Emergency Medical Services (HEMS)-based system. Methods We constructed a GIS model to estimate ground and helicopter transport times. Time-dependent rates of ECPR eligibility were derived from the Resuscitation Outcome Consortium (ROC) database, while the Cardiac Arrest Registry to Enhance Survival (CARES) registry determined the number of OHCA patients meeting ECPR criteria within designated transportation times. Emergency Medical Services (EMS) response time, ECPR candidacy determination time, and on-scene time were modeled based on data from the EROCA trial. The combined model was used to estimate the total ECPR eligibility in each system. Results The CARES registry recorded 736,066 OHCA patients from 2013 to 2021. After applying clinical criteria, 24,661 (3.4%) ECPR-indicated OHCA were identified. When considering overall ECPR eligibility within 45 min from OHCA to initiation, only 11.76% of OHCA where ECPR was indicated were eligible in the current hospital-based system. The prehospital ECPR HEMS-based system exhibited a four-fold increase in ECPR eligibility (49.3%), while the prehospital ground-based system showed a more than two-fold increase (28.4%). Conclusions The study demonstrates a two-fold increase in ECPR eligibility for a prehospital ECPR ground-based system and a four-fold increase for a prehospital ECPR HEMS-based system compared to the current hospital-based ECPR system. This novel GIS model can inform future ECPR implementation strategies, optimizing systems of care.

Differences in Out-of-Hospital Cardiac Arrest Outcomes Among 5 Racial/Ethnic Groups

Objective Out-of-hospital cardiac arrest (OHCA) is a major health problem and one of the leading causes of death in adults older than 40. Multiple prior studies have demonstrated survival disparities based on race/ethnicity, but most of these focus on a single racial/ethnic group. This study evaluated OHCA variables and outcomes among on 5 racial/ethnic groups. Methods This is a retrospective review of data for adult patients in the Cardiac Arrest Registry to Enhance Survival (CARES) from 3 racially diverse urban counties in the San Francisco Bay Area from May 2009 to October 2021. Stratifying by 5 racial/ethnic groups, we evaluated patient survival outcomes based on patient demographics, emergency medical services response location, cardiac arrest characteristics, and hospital interventions. Adjusted risk ratios were calculated for survival to hospital discharge, controlling for sex, age, response locations, median income of response location, arrest witness, shockable rhythm, and bystander cardiopulmonary resuscitation as well as clustering by census tract. Results There were 10,757 patient entries analyzed: 42% White, 24% Black, 18% Asian, 9.3% Hispanic, 6.0% Pacific Islander, 0.7% American Indian/Alaska Native, and 0.1% multiple races selected; however, only the first 5 racial/ethnic groups had sufficient numbers for comparison. The adjusted risk ratio for survival to hospital discharge was lower among the 4 racial/ethnic groups compared with the White reference group: Black (0.79, p = 0.003), Asian (0.78 p = 0.004), Hispanic (0.79, p = 0.018), and Pacific Islander (0.78, p = 0.041) groups. The risk difference for positive neurologic outcome was also lower among all 4 racial/ethnic groups compared with the White reference group. Conclusions The Black, Asian, Hispanic, and Pacific Islander groups were less likely to survive to hospital discharge from OHCA when compared with the White reference group. No variables were associated with decreased survival across any of these 4 groups.

The Public Health and Economic Impact of Drug Overdose Out-of-Hospital Cardiac Arrest in the United States

Objective To calculate disability-adjusted life years (DALY) and labor productivity loss due to drug overdose out-of-hospital cardiac arrest (DO-OHCA) and compare its contribution to the burden of disease and economic impact of all-cause nontraumatic out-of-hospital cardiac arrest (OHCA) in the US. Methods We performed a retrospective observational cohort analysis of all adult (age ≥18 years) nontraumatic emergency medical services-treated OHCA events, including those due to DO-OHCA, from the national Cardiac Arrest Registry to Enhance Survival (CARES) database from January 1, 2017 and December 31, 2020. The main outcome measures of interest were disability-adjusted life years, annual, and lifetime labor productivity loss over the 4-year study period. The findings for the study population were extrapolated to a national level using the CARES population catchment and U.S. population estimates by year. Results A total of 378,088 adult OHCA events, including 23,252 DO-OHCA (6.2%) met study inclusion criteria. The DO-OHCA DALY increased from 156,707 in 2017 to 265,692 in 2020. Per year, DO-OHCA contributed to 11.4%, 12.0%, 10.5%, and 11.4% of all OHCA DALY lost from 2017-2020, respectively. The mean annual and lifetime productivity losses for all OHCA were stable over time (annual: $47K in 2017 to $50K in 2020; lifetime: $647K in 2017 to $692K in 2020). The CARES population catchment increased by 39.8% over the study period (102.6 M in 2017 to 143.4 M in 2020). For DO-OHCA, the mean annual productivity loss was approximately 30% higher than non-DO-OHCA ($64K vs. $49K in 2020, respectively). The mean lifetime productivity loss for DO-OHCA was 2.5 times higher than non-DO-OHCA ($1.6 M vs. $630K in 2020, respectively). Conclusions The DALY due to DO-OHCA has increased over time with expansion of the CARES dataset, but its relative contribution to total OHCA DALY (all non-traumatic etiologies) remained fairly stable. The DO-OHCAs represent approximately 6% of all adult non-traumatic EMS-treated OHCA events but has a disproportionately greater economic impact. Continued efforts to reduce DO-OHCA through public health initiatives are warranted to lessen the societal impact of OHCA in the U.S.

Sex Differences in Receipt of Bystander Cardiopulmonary Resuscitation Considering Neighborhood Racial and Ethnic Composition.

Bystander cardiopulmonary resuscitation (B-CPR) and defibrillation for out-of-hospital cardiac arrest (OHCA) vary by sex, with women being less likely to receive these interventions in public. It is unknown whether sex differences persist when considering neighborhood racial and ethnic composition. We examined the odds of receiving B-CPR stratified by location and neighborhood. We hypothesized that women in predominantly Black neighborhoods will have a lower odds of receiving B-CPR. We conducted a retrospective study using the Cardiac Arrest Registry to Enhance Survival (CARES). Neighborhoods were classified by census tract. We modeled the odds of receipt of B-CPR (primary outcome), automatic external defibrillation application, and survival to hospital discharge (secondary outcomes) by sex. CARES collected 457 621 arrests (2013-2019); after appropriate exclusion, 309 662 were included. Women who had public OHCA had a 14% lower odds of receiving B-CPR (odds ratio [OR], 0.86 [95% CI, 0.82-0.89]), but effect modification was not seen by neighborhood (P=not significant). In predominantly Black neighborhoods, women who had public OHCA had a 13% lower odds of receiving B-CPR (adjusted OR, 0.87 [95% CI, 0.76-0.98]) and 12% lower odds of receiving automatic external defibrillation application (adjusted OR, 0.88 [95% CI, 0.78-0.99]). In predominantly Hispanic neighborhoods, women who had public OHCA were less likely to receive B-CPR (adjusted OR, 0.83 [95% CI, 0.73-0.96]) and less likely to receive automatic external defibrillation application (adjusted OR, 0.74 [95% CI, 0.64-0.87]). Women with public OHCA have a decreased likelihood of receiving B-CPR and automatic external defibrillation application. Findings did not differ significantly according to neighborhood composition. Despite this, our work has implications for considering strategies to reduce disparities around bystander response.

Cardiac Arrest Following Drug Overdose in the United States: An Analysis of the Cardiac Arrest Registry to Enhance Survival.

Given increases in drug overdose-associated mortality, there is interest in better understanding of drug overdose out-of-hospital cardiac arrest (OHCA). A comparison between overdose-attributable OHCA and nonoverdose-attributable OHCA will inform public health measures. We analyzed data from 2017 to 2021 in the Cardiac Arrest Registry to Enhance Survival (CARES), comparing overdose-attributable OHCA (OD-OHCA) with OHCA from other nontraumatic causes (non-OD-OHCA). Arrests involving patients <18 years, health care facility residents, patients with cancer diagnoses, and patients with select missing data were excluded. Our main outcome of interest was survival with good neurological outcome, defined as Cerebral Performance Category score 1 or 2. From a data set with 537 100 entries, 29 500 OD-OHCA cases and 338 073 non-OD-OHCA cases met inclusion criteria. OD-OHCA cases involved younger patients with fewer comorbidities, were less likely to be witnessed, and less likely to present with a shockable rhythm. Unadjusted survival to hospital discharge with Cerebral Performance Category score =1 or 2 was significantly higher in the OD-OHCA cohort (OD: 15.2% versus non-OD: 6.9%). Adjusted results showed comparable survival with Cerebral Performance Category score =1 or 2 when the first monitored arrest rhythm was shockable (OD: 28.9% versus non-OD: 23.5%, P=0.087) but significantly higher survival rates with Cerebral Performance Category score =1 or 2 for OD-OHCA when the first monitored arrest rhythm was nonshockable (OD: 9.6% versus non-OD: 3.1%, P<0.001). Among patients presenting with nonshockable rhythms, OD-OHCA is associated with significantly better outcomes. Further research should explore cardiac arrest causes, and public health efforts should attempt to reduce the burden from drug overdoses.

Statewide implementation of the cardiac arrest registry to enhance survival in Ohio

ObjectivePublic health surveillance is essential for improving community health. The Cardiac Arrest Registry to Enhance Survival (CARES) is a surveillance system for out-of-hospital cardiac arrest (OHCA). We describe results of the organized statewide implementation of Ohio CARES. MethodsWe performed a retrospective analysis of CARES enactment in Ohio. Key elements included: establishment of statewide leadership, appointment of a dedicated coordinator, conversion to a statewide subscription, statewide dissemination of information, fundraising from internal and external stakeholders, and conduct of resuscitation academies. We identified all adult (≥18 years) OHCA reported in the registry during 2013–2020. We evaluated OHCA characteristics before (2013–2015) and after (2016–2019) statewide implementation using chi-square test. We evaluated trends in OHCA outcomes using the Cochran-Armitage test of trend. ResultsStatewide CARES promotion increased participation from 2 (urban) to 136 (129 urban, 7 rural) EMS agencies. Covered population increased from 1.2 M (10% of state) to 4.8 M (41% of state). After statewide implementation, OHCA populations increased male (58.1% vs 60.8%, p < 0.01), white (50.1% vs 63.7%, p < 0.01), bystander witnessed (26.9% vs 32.9%, p < 0.01) OHCAs. Bystander CPR (34.7% vs 33.2%, p = 0.22), bystander AED (13.5% vs 12.3%, p = 0.55) and initial rhythm (shockable 18.0% vs 18.3%, p = 0.32) did not change. From 2013 to 2019 there were temporal increases in ROSC (29.7% to 31.9%, p-trend = 0.028), survival (7.4% to 12.3%, p-trend < 0.001) and survival with good neurologic outcome (5.6% to 8.6%, p-trend = 0.047). ConclusionThe organized statewide implementation of CARES in Ohio was associated with marked increases in community uptake and concurrent observed improvements in patient outcomes. These results highlight key lessons for community-wide fostering of OHCA surveillance.

Abstract 417: Advanced vs. Basic Life Support Outcome Variation in the Treatment of Out-of-Hospital-Cardiac-Arrest in Detroit

Background: Out-of-Hospital-Cardiac-Arrest (OHCA) may be treated with Advanced Life Support (ALS) and Basic Life Support (BLS). Previous literature has indicated that ALS provides no additional benefit to OHCA patients. This study compared OHCA outcomes between prehospital ALS or BLS care in a city with a preponderance of BLS only care. Study Objectives: To test for associations between prehospital ALS or BLS care stratified by initial cardiac rhythm on ROSC, discharged alive from the hospital, and on favorable neurological outcome at hospital discharge in OHCA of a presumed cardiac origin. Methods: A retrospective cohort of 6746 patients with non-traumatic OHCA who received CPR from a transporting EMS agency was collected using the Cardiac Arrest Registry to Enhance Survival (CARES) database. Patients were sorted into 4 cohorts based on ALS vs BLS care and initial shockable vs non-shockable cardiac rhythms. Cohorts were compared utilizing chi-squared and multivariable logistic regression analysis against the outcome variables of sustained ROSC, discharged alive from the hospital, and a favorable neurological outcome at hospital discharge. Results: After controlling for covariates, the odds of sustained ROSC were statistically significantly higher for S-ALS vs. NS-BLS (OR=4.4, p.001), S-BLS vs. NS-BLS (OR=1.8, p.001), and NS-ALS vs. NS-BLS (OR=2.2, p.001). The association between cohort and discharged alive from the hospital was also statistically significant (p.001), and discharged alive rates were S-ALS (17.9%); S-BLS (11.8%); NS-ALS (3.7%); NS-BLS (4.0%). The association between cohort and favorable neurological outcome was also statistically significant (p.001), and outcome rates were S-ALS (74.6%); S-BLS (58.2%); NS-ALS (36.5%); NS-BLS (41.6%). The odds of favorable neurological outcome were higher for S-ALS vs. NS-BLS (OR=2.6, p.001). Conclusion: In contrast to previous literature, ALS care in the study was superior to BLS care. ALS care was associated with higher rates of ROSC in OHCA patients regardless of rhythm. Further, ALS care was associated with higher rates of being discharged alive from the hospital and favorable neurological outcomes among patients with a shockable rhythm.

Abstract 406: Texas Out of Hospital Cardiac Arrest Disparities for Rural Patient Care From Statewide Out-of-Hospital Cardiac Arrest Data Registry - The Texas Cares Project

Introduction: Out-of-hospital cardiac (OHCA) arrest victims from rural settings suffer worse outcomes. We evaluated the association between rural setting and post-arrest care and outcomes. Hypothesis: Receiving treatment for OHCA at a rural hospital will be associated with a lower rate of post OHCA care and lower rate of favorable neurologic outcomes (cerebral performance score 1 or 2). Methods: We performed a retrospective analysis of the Texas Cardiac Arrest Registry to Enhance Survival (CARES) from 2014-2021. We included adult OHCAs not listed as DNR. We defined hospital urbanicity as the proportion of OHCAs originating from rural census tracts. We defined hospitals as rural if more than 25% of included OHCAs were rural. We evaluated the association between rural hospital status and patient and prehospital care characteristics - age, race, initial rhythm, response time, bystander CPR - and hospital care characteristics - targeted temperature management (TTM) and percutaneous coronary intervention (PCI) rates. We evaluated the association between rural hospital status and favorable neurological outcomes with logistic regression, adjusted for patient and prehospital factors, hospital care, and census tract median household income. Results: We included 31,569 encounters with OHCA at 161 unique hospitals. The rural hospital group included 1,213 OHCA encounters (3.8%) at 25 hospitals (15.5%). Patient factors between groups were similar other than a higher rate of white patients in the rural group. Rates of angiography (16.1% non rural, 17.1% rural), PCI (8.2%, 8.7%), and TTM (30.6%,34.7%) were not statistically different. Treatment at rural hospitals was not associated with a statistically significant decreased odds of good neurological outcome (aOR 1.02, 95%ci 0.83-1.24). Conclusion: Treatment for OHCA at rural hospitals was not associated with a lower rate of post OHCA care or lower rate of favorable neurologic outcome

Abstract 266: Texas Out of Hospital Cardiac Arrest Gender Disparities From Statewide Out-of-Hospital Cardiac Arrest Data Registry - The Texas Cares Project

Introduction: Female out-of-hospital cardiac arrest (OHCA) victims experience differences in care and worse rates of survival compared to male victims. Gender differences in time spent by prehospital care teams on scene with patients has not been studied. Hypothesis: There are gender disparities in scene time and outcomes. Increased scene time is associated with worse outcomes for Males and Females. Methods: We performed a retrospective, cohort study of the Texas Cardiac Arrest Registry to Enhance Survival (CARES) from 2014-201. We included adult OHCAs not witnessed by prehospital personnel that included scene time data and did not result in return of spontaneous circulation in the field that were transferred to emergency departments for ongoing resuscitation. We described OHCA demographics. We evaluated the association between gender and scene time. Using multivariable logistic regression, we evaluated the association of scene time with favorable neurologic outcome, (cerebral performance category (CPC) of 1 or 2). Results: We include 11,782 encounters with OHCA not witnessed by prehospital personnel, of these 7,185 were male and 4,597 female. Female OHCAs were older than male (mean 63.7 vs 61.3, p &amp;lt; 0.01). Female patients had slightly longer scene times than males (mean 29.2 vs 27.9). Female patients were less likely to have favorable neurologic outcomes (12.5% women vs 17.3% men, p &lt; 0.01 by chi2). Adjusting for age, gender, race, initial rhythm and bystander CPR in the multivariable model, increased scene time remained associated with a lower odds of favorable neurologic outcome (OR 0.96, 95%CI 0.95-0.96). Conclusions: OHCAs with longer duration scene time were associated with a lower likelihood of favorable neurologic outcome. Female patients were likely to have longer scene time duration and worse rate of favorable neurologic outcome.

Abstract 430: Impact of the COVID-19 Pandemic on Out-of-Hospital Cardiac Arrest (OHCA) in Wayne County, Michigan

Background: The COVID-19 pandemic has affected the incidence, presentation, care, and survival of OHCA. Early in the pandemic, healthcare systems were challenged by work force reduction due to illness and supply chain disruptions. We hypothesize there was an increase in the number of OHCA and a decrease in patient survival during the COVID-19 pandemic. Methods: We analyzed data from the Michigan Cardiac Arrest Registry to Enhance Survival (CARES) from 2018-2022 in Wayne County from two systems of care, Health Emergency Medical Services (HEMS) and Detroit East Medical Control Authority (DEMCA). We compared patient arrests and response characteristics during time periods: 2018-2019 (pre COVID-19), 2020-2021 (COVID-19), and 2022. Descriptive statistics were utilized for this retrospective review. Results: 40 EMS agencies are included, and 12,695 OHCA cases were identified. HEMS and DEMCA recorded a total of 2,262 OHCA in 2018 and 2,401 in 2019. OHCA increased to 2,797 in 2020, 2,652 in 2021, and to 2,583 in 2022. There was a 6.1% increase in OHCA from 2018 to 2019, and a 16.5% increase in 2020, with a decrease of 6.4% in both 2021 and 2022. This trend is similarly observed in the rate of asystole as presenting rhythm. In 2018 and 2019, an average of 46.8% of patients were pronounced in the emergency department (ED) or on scene. This average rose to 56.8% in 2020 and 2021 and was 47.9% in 2022. There was also a decline in the average percentage of patients surviving until hospital admission, 23.3% in 2018 and 2019 and decreased to 18.4% in 2020 and 2021, and 22.5% in 2022. ( Figure 1. ) Conclusion: The COVID-19 pandemic may have impacted pre-hospital mortality and morbidity. There was an increase in OHCA and asystole as a presenting rhythm. The percentage of patients pronounced in the ED or on scene also increased. This data demonstrates that as a region, we have not returned to pre-pandemic levels and survivability for OHCA. Figure 1. Comparison of OHCA EMS Runs from 2018-2022 in Wayne County, MI

Abstract 385: Comparison of Rapid Implementation of Automated Head and Thorax Elevation With Active Compression Decompression Cardiopulmonary Resuscitation and an Impedance Threshold Device versus National Outcome Data: A Prospective Observational Study

Background: Pre-clinical work has shown automated head and thorax elevation with active compression decompression CPR and an impedance threshold device (AHUP-CPR) improved 24-hour neurological survival. Propensity matched studies of out-of-hospital-cardiac arrest (OHCA) patients have shown a time dependent association between survival to hospital discharge (SHD) and application of AHUP CPR.Hypothesis: Rapid application of AHUP CPR for OHCA will have a higher incidence of SHD compared to national data. Methods: This is an ongoing prospective observational study of patients from an AHUP-CPR registry of non-traumatic adult OHCA receiving AHUP CPR as part of first responder care. OHCA patients from pre-hospital sites that consistently implemented rapid AHUP CPR were included. Patient demographics, arrest characteristics, ROSC, SHD, and SHD with favorable neurological function, defined as a Cerebral Performance Category score of 1 or 2, were recorded. Data are reported as means ± SD. Combined 2021 and 2022 data from the Cardiac Arrest Registry to Enhance Survival (CARES) were used for comparison of the primary study endpoint, SHD, and secondary endpoints. Chi-square testing was used to compare outcomes. Results: Of 11 registry sites, 7 (US States AL, FL, IL, MN, OK, TN, VA) met inclusion criteria and 1457 patients from January 2020 to June 2023 were enrolled. Average age was 65 ± 16.4 years, 61.8% (901) were male, and 71% (1035) received AHUP CPR. Average time (mm:ss) from 9-1-1 call to start of CPR was 9:52 (6:47) and time to start of AHUP CPR was 12:59 (5:51). Presenting rhythms were: asystole 47.8% (696), PEA 25.8% (376), and VF 20.5% (298). For all AHUP patients, SHD was 13.6% (198) versus 9.2% (26316/286525) for CARES (p &lt; 0.0001). SHD with favorable neurological function was higher for AHUP (10.3% (150) versus 7.3% for CARES (20889), p &lt; 0.0001) and ROSC (29.4% (428) vs 27.0% (77301), p = 0.039). Conclusions: In an unadjusted analysis, the incidence of SHD, ROSC, and neurologically favorable SHD with rapid implementation of AHUP-CPR was higher than nationally reported data. These results support prior findings of a time sensitive association between survival and time to AHUP-CPR. Additional analyses and study are needed for confirmation.

Abstract 380: Prehospital Ground and Helicopter-Based Extracorporeal Cardiopulmonary Resuscitation (ECPR) Reduce Barriers to ECPR: A GIS Model

Introduction: Evidence suggests that ECPR can improve survival rates for nontraumatic out-of-hospital cardiac arrest (OHCA). However, over 50% of potential ECPR candidates are unable to qualify in the current hospital-based system due to geographic limitations. This study employs a Geographic Information System (GIS) model to estimate the number of ECPR eligible patients within the U.S. in the current hospital-based system, a prehospital ECPR ground-based system, and a prehospital ECPR HEMS-based system (Figure 1). Methods: We constructed a GIS model to estimate ground and helicopter transport times. Time-dependent rates of ECPR eligibility were derived from the Resuscitation Outcome Consortium (ROC) database, while the Cardiac Arrest Registry to Enhance Survival (CARES) registry determined the number of OHCA patients meeting ECPR criteria within designated transportation times. EMS response time, ECPR candidacy determination time, and on-scene time were modeled based on data from the EROCA trial (Figure 1). The combined model was used to estimate the total ECPR candidates in each system. Results: The CARES registry recorded 736,066 OHCA patients from 2013 to 2021. After applying clinical eligibility criteria, 24,661 (3.4%) patients were eligible for ECPR. When considering overall ECPR eligibility within 45 minutes from OHCA to initiation, only 11.76% of clinically eligible patients qualified in the current hospital-based system. The prehospital ECPR HEMS-based system exhibited a four-fold increase in ECPR eligibility (49.3%), while the prehospital ground-based system showed a more than two-fold increase (28.4%). Conclusions: The study demonstrates a two-fold increase in ECPR eligibility for a field-deployable ground-based system and a four-fold increase for a prehospital ECPR HEMS-based system compared to the current hospital-based OHCA system. This novel GIS model can inform future ECPR implementation strategies, optimizing systems of care.

Abstract 125: The Association of Racial Residential Segregation and Survival to Discharge After Out-of-Hospital Cardiac Arrest in the United States

Introduction: Racial and economic segregation is associated with poor health outcomes, including out-of-hospital cardiac arrest (OHCA) survival. Prior work identified disparities in OHCA survival for Medicare beneficiaries associated with residential segregation. We sought to use registry data to evaluate this association of racial and economic segregation with OHCA survival to discharge. Methods: We conducted a retrospective analysis of the 2013-2021 Cardiac Arrest Registry toEnhance Survival OHCA dataset. Arrests with missing data, pediatric patients, or EMS-witnessed were excluded. Our primary predictor, the index of concentration at the extremes(ICE), is a validated measure of racial and economic segregation. We examined three ICE measures (race, income, and race + income) calculated from US Census data and binned into tract-level quintiles. The primary outcome was survival to discharge. We performed multi-levelPoisson regression, with hospital random effect, and adjusted for age, gender, race and ethnicity, witness status, location, and bystander CPR to predict relative risk of survival to discharge and good neurological outcome. Results: We identified 624,626 adult OHCA patients with median age 64 years (SD 17), 38%female, 22% Black/African American, 50% White, 6.8% Hispanic/Latino. Overall, 156,712 (25%)survived to hospital admission, 10% survived to hospital discharge and 6.3% had good neurological outcome. Patients residing in the most segregated White and higher income tracts(Q5) had a 7-10% higher likelihood of survival to discharge compared to the most segregatedBlack and lower income communities (Q1) across all three measures (race RR: 1.09, CI 1.05-1.12; income RR: 1.07, CI 1.04-1.10; race + income RR: 1.10, CI 1.06-1.13). Similarly, neurological recovery was higher in Q5 (race RR: 1.20, CI 1.15-1.25; income RR: 1.12, CI 1.08-1.16; race + income RR: 1.19, CI 1.15-1.23) compared to Q1. Conclusion: We identified outcome disparities across three ICE measures for residents of the most segregated and lowest income Black census tracts compared to those in most segregated higher income White census tracts. Future work should focus on interventions for these disparities to improve survival and address health inequities.

Abstract 131: Sex-Based Differences in the Extracorporeal Cardiopulmonary Resuscitation Population for Out-of-Hospital Cardiac Arrest in the Minneapolis Metro Area

Background: Women constitute nearly 40% of out-of-hospital cardiac arrests (OHCA), receive less bystander CPR, and guideline-directed interventions such as post-arrest coronary angiography. Aims: To identify the presence of sex-based differences in utilization of extracorporeal cardiopulmonary resuscitation (ECPR) for refractory OHCA in the Minneapolis (MSP) metro area. Methods: Patients who met all eligibility criteria for the Minnesota Resuscitation Consortium (MRC) ECPR protocol between 2013-2021 were identified in the Cardiac Arrest Registry to Enhance Survival (CARES) registry. Patients who presented to the University of Minnesota (UMN) for the MRC ECPR protocol between 2014-2021 were identified. Arrest data, patient characteristics and mortality were compared between the sexes in both populations. Results: We identified 2790 OHCA patients through the CARES registry of whom 685 (24.6%) were women. There were 443 referrals to UMN for ECPR, of whom 87 (19.6%) were women. There were significantly more eligible women who arrested than those referred for ECPR (p =0.02). In the MSP metro area, women were more likely to suffer cardiac arrest at home (59% vs 66%, p&lt;0.01), less likely to receive bystander CPR (42% vs 35%, p&lt;0.01) and have greater time to professional CPR (6.3 vs 5.4 minutes, p&lt;0.01). Among referrals for MRC ECPR protocol, there were no differences in arrest characteristics or age between men and women. Multivariate analysis for neurologically favorable survival showed female sex was associated with decreased survival in the community (p=0.03), but trended towards increased survival in the UMN ECPR cohort (p=0.08) (Figure 1). Conclusion: Women suffering from cardiac arrest have higher mortality and are less likely to be referred for ECPR. However, after referral for ECPR, sex is not associated with survival. Pre-hospital factors result in fewer women referred for ECPR and warrant further investigation to identify potential interventions.

Abstract 264: Impact of Receiving Hospital on Disparities in Out-of-Hospital Cardiac Arrest

Background: Minority out-of-hospital cardiac arrest (OHCA) victims suffer from worse outcomes. The factors contributing to these disparities are not completely understood, and little is known about the impact of receiving hospital on OHCA. Hypothesis: Receiving hospital plays an important role in OHCA outcome disparities. Methods: We performed a retrospective, cohort study of the national Cardiac Arrest Registry to Enhance Survival (CARES). We included OHCAs from 2014- 2021 that survived to hospital admission. Based on census tract data, we stratified OHCAs based on majority race/ethnicity: &gt;50% White, &gt;50% Black, and &gt;50% Hispanic/Latino. We stratified hospitals into quartiles based on hospital rate of the outcome, survival with favorable neurologic outcome, cerebral performance category of 1 of 2. We evaluated the association between race/ethnicity and care at increasing hospital performance quartile. We compared four models evaluating the association between race/ethnicity and outcome: 1) omitting receiving hospital and bystander CPR (B-CPR), 2) adjusting for B-CPR, 2) additionally adjusting for receiving hospital as a random intercept, and 3) adjusting for hospital performance quartile. We adjusted all models for possible confounders. Results: We include 124,908 OHCAs that survived to hospital admission; 90,034 majority White, 20,600 majority Black, and 14,338 majority Hispanic. Compared to White, Black (OR 0.1, 95% CI 0.1-0.1) and Hispanic OHCAs were less likely to be cared for at high performing hospitals. Ignoring receiving hospital, outcomes were worse for Black (19.7%, aOR 0.43, 95% CI 0.40-0.46) and Hispanic (22.1%, aOR 0.49, 95% CI 0.45-0.54) than White (33.5%). While adjusting for B-CPR did not change survival odds, adjusting for receiving hospital as a random intercept improved outcome odds for Black (aOR 0.60, 95% CI 0.54-0.67) and Hispanic (aOR 0.61, 95% CI 0.53-0.69). Adjusting for hospital performance quartile also improved outcome odds for Black (aOR 0.79, 95% CI 0.73-0.85) and Hispanic/Latino (aOR 0.78, 95% CI 0.70-0.86). Conclusion: OHCAs from minority communities were less likely to be cared for at higher performing hospitals, and adjusting for receiving hospital significantly diminished OHCA outcome disparities.

Abstract 409: Burden of Overdose in Young Adult Cardiac Arrest Cases

Introduction: Overdose related out-of-hospital cardiac arrests (OHCA) are preventable devastating occurrences, often affecting young adults, leading to many years of productive life lost. The purpose of this study was to characterize overdose related OHCA over time and assess its excess burden in young adult cases in the state of Illinois. Methods: The Cardiac Arrest Registry to Enhance Survival (CARES) database was used. We excluded pediatric and trauma cases. Bivariate associations were assessed. Population attributable fractions (PAF) were also calculated. Results: During 2018 to 2022, a total of 23,637 non-traumatic adult OHCA cases were reported to CARES from Illinois (with a population catchment &gt;40% in 2022). Of these, 8.2% (N=1,928) were overdose related. Overdose accounts for 9.5% of the OHCA in males, and 5.9% in females. By race and ethnicity, 9.6% of cases in Hispanics, 9.3% in Blacks and 7.3% in Whites are due to overdose. The number of overdose related OHCA peaked in 2020 (n=449); however, 2022 (n=432) contributed to the historically highest proportion of overdose related OHCA (8.5%). While the overall mean age for OHCA was 63.7 (SD=17) years with a peak at 60 years, the mean age for overdose cases was 44.7 (SD=13.5) with a peak at 50 years. While young adults (18-34-year-olds) have a lower likelihood of cardiac arrests accounting for only 6% of the total OHCA, they contribute 26% of the overdose OHCA. Young adult OHCA cases are nearly six times more likely to be overdose related (Relative Risk=5.5; 95% CI: 5.0 - 6.0) as compared to older cases. In terms of population impact, 21% of the overdose related OHCA are attributed to young adult cases (PAF=0.212). If young adults had the same risk of overdose-related OHCA as older cases, we would expect 408 fewer overdose-related OHCA, and the rate of overdose-related OHCA would drop from 8.2% to 6.4%. Similarly, for adults &lt;40 years of age, 31% of the overdose related cardiac arrests are attributed to these young cases (PAF=0.309), and we would expect 596 fewer cases had the risk of overdose related OHCA been same as older cases. Conclusion: Overdose related OHCAs represent a significant burden in younger patients. Prevention strategies that reduce the burden of overdose related OHCA should be a public health priority.

Abstract 340: Automated External Defibrillator Utilization After Out-of-Hospital Cardiac Arrest at Recreational Facilities in the United States

Background: Given the importance of public access defibrillation, some U.S. states have passed laws requiring an automatic external defibrillator (AED) to be available on-site at athletic facilities. However, rates of bystander AED application during out-of-hospital cardiac arrest (OHCA) in states with and without such laws remain unknown. Research Question: What are the rates of bystander AED application during OHCA at recreational facilities in U.S. states that mandate AEDs availability at such locations? Aim: To examine the rates of bystander AED application for OHCA at recreational facilities in states with and without laws mandating the presence of AEDs at athletic facilities. Methods: We included adults (≥18 years) in the Cardiac Arrest Registry to Enhance Survival (CARES) registry with a non-traumatic OHCA during 2013-2021 at a recreational facility in the U.S. The primary outcome was bystander AED application during OHCA. Secondary outcomes included survival to hospital admission and survival to hospital discharge. We examined the rates of bystander AED application and survival outcomes in states with laws that mandate AEDs at athletic facilities and in states without such laws. Results: Overall, there were 4,145 OHCAs cases at recreational facilities in 13 states that mandated AEDs at athletic facilities and 5,145 cases in 27 states that did not. In states with laws, the median rate of bystander AED application was 19.0%, with large between-state variation (IQR: 15.1%-22.0%). The median rate of survival to hospital admission was 44.5% (IQR 39.4%-56.9%) and survival to hospital discharge was 31.0% (IQR 25.2%-32.8%). In non-law states, the median rate of bystander AED application was 18.2% (IQR: 13.9%-25.0%). The median rate of survival to hospital admission was 45.0% (IQR 38.4%-52.1%) and survival to hospital discharge was 28.4% (IQR 25.9%-37.5%). Conclusions: Despite state laws that mandate on-site availability of an AED, rates of bystander AED application for OHCA at recreational facilities in such states remain low, with notable state-level variability. Our findings highlight that improving bystander AED application during OHCA will need to go beyond making AEDs available on-site.

Abstract 410: Differences in Survivability of Out-of-Hospital Cardiac Arrest in Rural versus Urban Minnesota

Background: Out-of-Hospital Cardiac Arrest (OHCA) survival has improved in North America due to improved awareness, training, and bystander CPR. An important factor complicating OHCA survival is location on initial arrest, due to distance and access to emergency medical services (EMS). Aims: We sought to examine characteristics of OHCA encounters in Minnesota and determine underlying factors for differences in OHCA survival in rural versus urban areas. Methods: We examined data from the Cardiac Arrest Registry to Enhance Survival (CARES) registry between 2013-2021 in Minnesota. The analyses included encounters from 31 EMS services across the state. The Office of Management and Budget (OMB) county rural-urban classification schema was used to designate categories of rural (non-metropolitan counties of less than 50,000 population) versus urban (metropolitan counties with populations of 50,000 or more). Results: We identified 21,257 patient encounters, of which 3,524 (16.6%) of encounters were designated as rural and 17,733 (83.4%) as urban. In our cohort, patients were predominately male. Rural arrest patients tended to be older (mean age, 64.5 vs 60.6 years, p&lt;0.01) and had a higher prevalence of heart disease (32.2% vs 26.9%, p&lt;0.01). Rural arrests were more likely to be witnessed (57.1% vs 51.6%, p&lt;0.01), receive bystander CPR (42.3% vs 35.2%, p&lt;0.01), and have AED use prior to EMS arrival (55.7% vs 53.5%, p&lt;0.01). The average time for EMS arrival at scene of arrest was longer among rural encounters (12.9 vs 10.6 minutes; p&lt;0.01). Overall, survival-to-discharge was significantly lower among rural versus urban communities (9.3% vs 13.1%, p&lt;0.01). Conclusion: In this analysis of the CARES dataset in Minnesota, there were significant differences in survival characteristics between rural vs urban OHCA patients. These findings warrant greater investment in rural EMS agencies and modifiable resuscitation practices to improve survival among rural communities.