Background Factors associated with out‐of‐hospital cardiac arrest (OHCA) outcome disparities remain poorly understood. We evaluated the role of receiving hospital on OHCA outcome disparities. Methods and Results We studied people with OHCA who survived to hospital admission from TX‐CARES (Texas Cardiac Arrest Registry to Enhance Survival), 2014 to 2021. Using census data, we stratified OHCAs into majority (>50%) strata: non‐Hispanic White race and ethnicity, non‐Hispanic Black race and ethnicity, and Hispanic or Latino ethnicity. We stratified hospitals into performance quartiles based on the primary outcome, survival with good neurologic outcome. We evaluated the association between race and ethnicity and care at higher‐performance hospitals. We compared 3 models evaluating the association between race and ethnicity and outcome: (1) ignoring hospital, (2) adjusting for hospital as a random intercept, and (3) adjusting for hospital performance quartile. We adjusted models for possible confounders. We included 10 434 OHCAs. Hospital performance quartile outcome rates ranged from 11.3% (fourth) to 37.1% (first). Compared with OHCAs in neighborhoods of majority White race, those in neighborhoods of majority Black race (odds ratio [OR], 0.1 [95% CI, 0.1–0.1]) and Hispanic or Latino ethnicity (OR, 0.2 [95% CI, 0.2–0.2]) were less likely to be cared for at higher‐performing hospitals. Compared with White neighborhoods (30.1%) and ignoring hospital, outcomes were worse in Black neighborhoods (15.4%; adjusted OR [aOR], 0.5 [95% CI, 0.4–0.5]) and Hispanic or Latino neighborhoods (19.2%; aOR, 0.6 [95% CI, 0.5–0.7]). Adjusting for hospital as a random intercept, outcomes improved for Black neighborhoods (aOR, 0.9 [95% CI, 0.7–1.05]) and Hispanic or Latino neighborhoods (aOR, 0.9 [95% CI, 0.8–0.99]). Adjusting for hospital performance quartile, outcomes improved for Black neighborhoods (aOR, 0.8 [95% CI, 0.7–1.01]) and Hispanic or Latino neighborhoods (aOR, 0.9 [95% CI, 0.8–0.996]). Conclusions In Black and Hispanic or Latino communities, OHCAs were less likely to be cared for at higher‐performing hospitals, and adjusting for receiving hospital improved OHCA outcome disparities.

Background Most studies on bystander cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrest (OHCA) have focused on in-hospital or short-term survival. Objectives The purpose of this study was to examine the association between bystander CPR and long-term survival outcomes for OHCA. Methods Within the Cardiac Arrest Registry to Enhance Survival, we identified 152,653 patients with OHCA ≥65 years of age or older. Using multivariable hierarchical logistic regression, we first examined the association between bystander CPR and in-hospital survival. Then, among those surviving to discharge and linked to Medicare files, we evaluated the association between bystander CPR and long-term mortality over 5 years using multivariable Cox regression. Results Overall, 58,464 (38.3%) received bystander CPR. Patients receiving bystander CPR were more likely to have an OHCA that was witnessed, in a public location, and with an initial shockable rhythm. Bystander CPR was associated with a 24% higher likelihood of surviving to hospital discharge (10.2% vs 5.5%; adjusted relative risk: 1.24 [95% CI: 1.19-1.29]; P < 0.001), and this survival benefit was similar (interaction P = 0.24) for those who were 65 to 74, 75 to 84, and ≥85 years of age. Among patients surviving to hospital discharge (median follow-up of 31 months), bystander CPR was additionally associated with lower long-term mortality vs those without bystander CPR (adjusted hazard ratio: 0.78 [95% CI: 0.73-0.84]; P < 0.001), and this benefit was also consistent across age groups (interaction P = 0.13). Conclusions In older adults with OHCA, bystander CPR was associated with higher rates of in-hospital survival. This survival benefit was not attenuated by competing mortality risks but increased in magnitude after hospital discharge.

Background Survival for out-of-hospital cardiac arrest (OHCA) varies across emergency medical service (EMS) agencies. Yet, little is known about resuscitation response and quality improvement activities at EMS agencies. We describe herein a novel survey to EMS agencies in a U.S. registry for OHCA. Methods Using data from the Cardiac Arrest Registry to Enhance Survival (CARES), we identified 577 EMS agencies with ≥10 OHCA cases annually between 2015 and 2019 that remained active in CARES. We administered a survey to EMS directors regarding agency characteristics, cardiac arrest response, relationships with first responders and dispatchers, quality improvement activities and perceived barriers in the community. Results Of eligible EMS agencies, 470 (81.5%) completed the survey. The high completion rate was likely due to frequent personalized emails and phone calls, liaising with CARES state coordinators to encourage survey response, and multiple periodic drawings of an automated external defibrillator during the survey period for participating EMS agencies. The survey examined rates of resuscitation training modalities; use of resuscitation equipment and devices in the field; frequency of simulation; non-EMS stakeholder response to OHCA (dispatchers, fire, police); quality improvement; and community factors affecting bystander response to OHCA. Conclusions In this study design paper on the RED-CASO survey, we provide summary data on EMS agency characteristics in the U.S. Upon linkage to CARES patient-level data, this survey will provide critical insights into ‘best practices’ at EMS agencies with the highest OHCA survival rates as well as provide insights into current disparities in outcomes.

Background: For out-of-hospital cardiac arrest (OHCA), assignment of race/ethnicity data can be challenging. Validation of race/ethnicity in registry data with patients’ self-reported race/ethnicity would provide insights regarding misclassification. Methods: Using recently linked 2013–2019 Cardiac Arrest Registry to Enhance Survival (CARES) data with Medicare files, we examined the concordance of race/ethnicity in CARES with self-reported race/ethnicity in Medicare. Among patients with unknown race/ethnicity in CARES, race/ethnicity data from Medicare files were reported. Results: Of 26,875 patients in the linked data, 5757 (21.4%) had unknown race/ethnicity in CARES. Of the remaining 21,118 patients, 14,284 (67.6%) were identified in CARES as non-Hispanic White, 4771 (22.6%) as non-Hispanic Black, 1213 (5.7%) as Hispanic, 760 (3.6%) as Asian or Pacific Islander, and 90 (0.4%) as American Indian or Alaskan Native. The concordance rate for race/ethnicity between CARES and Medicare was 93.4% for patients reported as non-Hispanic White in CARES, 89.1% for non-Hispanic Blacks, 74.6% for Hispanics, 69.6% for Asians and Pacific Islanders, and 37.8% for American Indian or Alaskan Natives. For the 5757 patients with unknown race/ethnicity in CARES, 3973 (69.0%) self-reported in Medicare as non-Hispanic White, 617 (10.7%) as non-Hispanic Black, 425 (7.4%) as Hispanic, 491 (8.5%) as Asian or Pacific Islander, and 52 (0.9%) as American Indian or Alaskan Native. Race/ethnicity remained unknown in 199 (3.5%) of patients. Conclusion: Race/ethnicity in CARES was highly concordant with self-reported race/ethnicity in Medicare, especially for non-Hispanic White and Black individuals. For patients with unknown race/ethnicity data in CARES, the vast majority were of White race.

Background: Out-of-hospital cardiac arrest (OHCA) is one of the leading causes of death and disability worldwide. Overall survival after an OHCA has been reported to be poor and limited studies have been conducted in developing countries. We aimed to investigate the rates of survival from OHCA and explore components of the chain of survival in a developing country. Methods: We conducted a multicenter prospective cohort study in the emergency departments (ED) of five major public and private sector hospitals of Karachi, Pakistan from January 2013 to April 2013. Twenty-four hour data collection was performed by trained data collectors, using a structured questionnaire. All patients ≥18 years of age, presenting with OHCA of cardiac origin, were included. Patients with do-not-resuscitate status or referred from other hospitals were excluded. Our primary outcome was survival of OHCA patients at the end of ED stay. Results: During the three month period, data was obtained from 310 OHCA patients. The overall survival to ED discharge was 1.6 % which decreased to 0 % at 2-months after discharge. More than half (58.3 %) of these OHCA patients were brought to the hospital in a non-EMS (emergency medical service) vehicle i.e. public or private transportation. Patients utilizing non-EMS transportation reached the hospital earlier with a median time of 23 min compared to patients utilizing any type of ambulances which had a delay of 7 min hospital reaching time (median time 30 min). However, patients utilizing ambulances with life-support facilities, as compared to all other types of pre-hospital transportation, had the shortest time to first life-support intervention (15 min). Most of the patients (92.9 %) had a witnessed cardiac arrest out of which only a small percentage (2.3 %) received bystander CPR (cardio pulmonary resuscitation). Median time from arrest to receiving first CPR was 20 min. Only 1 % of patients were found to have a shockable rhythm on first assessment. Conclusion: This study showed that the overall survival of OHCA is null in this population. Lack of bystander CPR and weaker emergency medical services (EMS) leading to a delay in receiving life-support interventions were some of the important observations. Poor survival emphasizes the need to standardize EMS systems, initiate public awareness programs and strengthen links in the chain of survival.

Background-Firefighter first responders dispatched in parallel with emergency medical services (EMS) personnel for out-ofhospital cardiac arrests (OHCA) can provide early defibrillation to improve survival. We examined whether survival following first responder defibrillation differed according to driving distance from nearest fire station to OHCA site. Methods and Results-From the CARES (Cardiac Arrest Registry to Enhance Survival) registry, we identified non-EMS witnessed OHCAs of presumed cardiac cause from 2010 to 2014 in Durham, Mecklenburg, and Wake counties, North Carolina. We used logistic regression to estimate the association between calculated driving distances (≤1, 1-1.5, 1.5-2, and >2 miles) and survival to hospital discharge following first responder defibrillation compared with defibrillation by EMS personnel. In total, 5020 OHCAs were included in the study. First responders more often applied the first automated external defibrillators at the shortest distances (≤1 mile) versus longest distances (>2 miles) (53.4% versus 46.6%, respectively, P<0.001). When compared with EMS defibrillation, first responder defibrillation within 1 mile and 1 to 1.5 miles of the nearest fire station was associated with increased survival to hospital discharge (odds ratio 2.01 [95% confidence interval 1.46-2.78] and odds ratio 1.61 [95% confidence interval 1.10-2.35], respectively). However, at the longest distances (1.5-2.0 and >2.0 miles), survival following first responder defibrillation did not differ from EMS defibrillation (odds ratio 0.77 [95% confidence interval 0.48-1.21] and odds ratio 0.97 [95% confidence interval 0.67-1.41], respectively). Conclusions-Shorter driving distance from nearest fire station to OHCA location was associated with improved survival following defibrillation by first responders. These results suggest that the location of first responder units should be considered when organizing prehospital systems of OHCA care.

Background The natural cycle of large‐scale wildfires is accelerating, increasingly exposing both rural and populous urban areas to wildfire emissions. While respiratory health effects associated with wildfire smoke are well established, cardiovascular effects have been less clear. Methods and Results We examined the association between out‐of‐hospital cardiac arrest and wildfire smoke density (light, medium, heavy smoke) from the National Oceanic Atmospheric Association's Hazard Mapping System. Out‐of‐hospital cardiac arrest data were provided by the Cardiac Arrest Registry to Enhance Survival for 14 California counties, 2015–2017 (N=5336). We applied conditional logistic regression in a case‐crossover design using control days from 1, 2, 3, and 4 weeks before case date, at lag days 0 to 3. We stratified by pathogenesis, sex, age (19–34, 35–64, and ≥65 years), and socioeconomic status (census tract percent below poverty). Out‐of‐hospital cardiac arrest risk increased in association with heavy smoke across multiple lag days, strongest on lag day 2 (odds ratio, 1.70; 95% CI, 1.18–2.13). Risk in the lower socioeconomic status strata was elevated on medium and heavy days, although not statistically significant. Higher socioeconomic status strata had elevated odds ratios with heavy smoke but null results with light and medium smoke. Both sexes and age groups 35 years and older were impacted on days with heavy smoke. Conclusions Out‐of‐hospital cardiac arrests increased with wildfire smoke exposure, and lower socioeconomic status appeared to increase the risk. The future trajectory of wildfire, along with increasing vulnerability of the aging population, underscores the importance of formulating public health and clinical strategies to protect those most vulnerable.

BACKGROUND: The HeartRescue Project is a multistate public health initiative focused on establishing statewide out-of-hospital cardiac arrest (OHCA) systems of care to improve case capture and OHCA care in the community, by emergency medical services (EMS), and at hospital level. METHODS AND RESULTS: From 2011 to 2015 in the 5 original HeartRescue states, all adults with EMS-treated OHCA due to a presumed cardiac cause were included. In an adult population of 32.8 million, a total of 64 988 OHCAs-including 10 046 patients with a bystander-witnessed OHCA with a shockable rhythm-were treated by 330 EMS agencies. From 2011 to 2015, the case-capture rate for all-rhythm OHCA increased from an estimated 39.0% (n=6762) to 89.2% (n=16 103; P<0.001 for trend). Overall survival to hospital discharge was 11.4% for all rhythms and 34.0% in the subgroup with bystander-witnessed OHCA with a shockable rhythm. We observed modest temporal increases in bystander cardiopulmonary resuscitation (41.8-43.5%, P<0.001 for trend) and bystander automated external defibrillator application (3.2-5.6%, P<0.001 for trend) in the all-rhythm group, although there were no temporal changes in survival. There were marked all-rhythm survival differences across the 5 states (8.0-16.1%, P<0.001) and across participating EMS agencies (2.7-26.5%, P<0.001). CONCLUSIONS: In the initial 5 years, the HeartRescue Project developed a population-based OHCA registry and improved statewide case-capture rates and some processes of care, although there were no early temporal changes in survival. The observed survival variation across states and EMS systems presents a future challenge to elucidate the characteristics of high-performing systems with the goal of improving OHCA care and survival.

Importance: Despite evidence that therapeutic hypothermia improves patient outcomes for out-of-hospital cardiac arrest, use of this therapy remains low. Objective: To determine whether the use of therapeutic hypothermia and patient outcomes have changed after publication of the Targeted Temperature Management trial on December 5, 2013, which supported more lenient temperature management for out-of-hospital cardiac arrest. Design, Setting, and Participants: A retrospective cohort was conducted between January 1, 2013, and December 31, 2016, of 45 935 US patients in the Cardiac Arrest Registry to Enhance Survival who experienced out-of-hospital cardiac arrest and survived to hospital admission. Exposures: Calendar time by quarter year. Main Outcomes and Measures: Use of therapeutic hypothermia and patient survival to hospital discharge. Results: Among 45 935 patients (17 515 women and 28 420 men; mean [SD] age, 59.3 [18.3] years) who experienced out-of-hospital cardiac arrest and survived to admission at 649 US hospitals, overall use of therapeutic hypothermia during the study period was 46.4%. In unadjusted analyses, the use of therapeutic hypothermia dropped from 52.5% in the last quarter of 2013 to 46.0% in the first quarter of 2014 after the December 2013 publication of the Targeted Temperature Management trial. Use of therapeutic hypothermia remained at or below 46.5% through 2016. In segmented hierarchical logistic regression analysis, the risk-adjusted odds of use of therapeutic hypothermia was 18% lower in the first quarter of 2014 compared with the last quarter of 2013 (odds ratio, 0.82; 95% CI, 0.71-0.94; P = .006). Similar point-estimate changes over time were observed in analyses stratified by presenting rhythm of ventricular tachycardia or ventricular fibrillation (odds ratio, 0.89; 95% CI, 0.71-1.13, P = .35) and pulseless electrical activity or asystole (odds ratio, 0.75; 95% CI, 0.63-0.89; P = .001). Overall risk-adjusted patient survival was 36.9% in 2013, 37.5% in 2014, 34.8% in 2015, and 34.3% in 2016 (P < .001 for trend). In mediation analysis, temporal trends in use of hypothermia did not consistently explain trends in patient survival. Conclusions and Relevance: In a US registry of patients who experienced out-of-hospital cardiac arrest, the use of guideline-recommended therapeutic hypothermia decreased after publication of the Targeted Temperature Management trial, which supported more lenient temperature thresholds. Concurrent with this change, survival among patients admitted to the hospital decreased, but was not mediated by use of hypothermia.

Background: Resuscitation centers may improve patient outcomes by achieving sufficient experience in post-resuscitation care. We analyzed the relationship between survival and hospital volume among patients suffering out-of-hospital cardiac arrest (OHCA). Methods: This prospective cohort investigation collected data from the Cardiac Arrest Registry to Enhance Survival database from 10/1/05 to 12/31/09. Primary outcome was survival to discharge. Hospital characteristics were obtained via 2005 American Hospital Association Survey. A hospital's use of hypothermia was obtained via direct survey. To adjust for hospital- and patient-level variation, multilevel, hierarchical logistic regression was performed. Hospital volume was modeled as a categorical (OHCA/year. ≤. 10, 11-39, ≥40) variable. A stratified analysis evaluating those with ventricular fibrillation or pulseless ventricular tachycardia (VF/VT) was also performed. Results: The cohort included 4125 patients transported by EMS to 155 hospitals in 16 states. Overall survival to hospital discharge was 35% among those admitted to the hospital. Individual hospital rates of survival varied widely (0-100%). Unadjusted survival did not differ between the 3 hospital groups (36% for ≤10 OHCA/year, 35% for 11-39, and 36% for ≥40; p=0.75). After multilevel adjustment, differences in survival across the groups were not statistically significant. Compared to patients at hospitals with ≤10 OHCA/year, adjusted OR for survival was 1.04 (CI950.83-1.28) among 11-39 annual volume and 0.97 (CI950.73-1.30) among the ≥40 volume hospitals. Among patients presenting with VF/VT, no difference in survival was identified between the hospital groups. Conclusion: Survival varied substantially across hospitals. However, hospital OHCA volume was not associated with likelihood of survival. Additional efforts are required to determine what hospital characteristics might account for the variability observed in OHCA hospital outcomes.