Improve Out-of-hospital Cardiac Arrest Survival Research Articles

Assessing Attitudes and Perceptions of High-Risk, Low-Resource Communities Towards Cardiopulmonary Resuscitation and Public-Access Defibrillation

Background: Layperson cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) use are vital for improving survival rates after out-of-hospital cardiac arrest (OHCA), yet their application varies by community demographics. We evaluated the concerns and factors influencing willingness to perform CPR and use AEDs among laypersons in high-risk, low-resource communities. Methods: From April 2022 to March 2024, laypersons in Northern Manhattan’s Community District 12 completed surveys assessing their attitudes toward CPR and AED use before attending Hands-Only CPR training. Fisher’s Exact Test assessed differences in concerns and willingness to perform CPR and AED use across racial-ethnic groups and compared low-resource communities with high-resource groups consisting of non-clinical staff across eight ambulatory sites. Results: Among 669 participants from low-resource communities, 64% identified as Hispanic, 58% were under 40 years of age, and 67% were female. Significant knowledge gaps were identified: 62% had never learned CPR, and 77% were unfamiliar with AEDs. Top concerns about giving CPR included fear of incorrect performance (67%), causing harm (56%), and legal repercussions (53%). Willingness to perform CPR was most influenced by familiarity with the victim. The primary barrier to AED use was a lack of operational knowledge (66%). Non-Hispanic Black participants expressed significantly greater concerns than their Non-Hispanic White counterparts. Participants in high-resource settings (n = 309) showed higher training rates, albeit with similar apprehensions about CPR and AED use. Conclusions: Concerns regarding CPR and AED use stem from a lack of confidence and training, particularly predominant in certain racial-ethnic groups. Targeted, culturally sensitive community interventions could potentially address these barriers, enhance preparedness, and improve OHCA survival rates.

Detecting cardiac states with wearable photoplethysmograms and implications for out-of-hospital cardiac arrest detection.

Out-of-hospital cardiac arrest (OHCA) is a global health problem affecting approximately 4.4million individuals yearly. OHCA has a poor survival rate, specifically when unwitnessed (accounting for up to 75% of cases). Rapid recognition can significantly improve OHCA survival, and consumer wearables with continuous cardiopulmonary monitoring capabilities hold potential to "witness" cardiac arrest and activate emergency services. In this study, we used an arterial occlusion model to simulate cardiac arrest and investigated the ability of infrared photoplethysmogram (PPG) sensors, often utilized in consumer wearable devices, to differentiate normal cardiac pulsation, pulseless cardiac (i.e., resembling a cardiac arrest), and non-physiologic (i.e., off-body) states. Across the classification models trained and evaluated on three anatomical locations, higher classification performances were observed on the finger (macro average F1-score of 0.964 on the fingertip and 0.954 on the finger base) compared to the wrist (macro average F1-score of 0.837). The wrist-based classification model, which was trained and evaluated using all PPG measurements, including both high- and low-quality recordings, achieved a macro average precision and recall of 0.922 and 0.800, respectively. This wrist-based model, which represents the most common form factor in consumer wearables, could only capture about 43.8% of pulseless events. However, models trained and tested exclusively on high-quality recordings achieved higher classification outcomes (macro average F1-score of 0.975 on the fingertip, 0.973 on the finger base, and 0.934 on the wrist). The fingertip model had the highest performance to differentiate arterial occlusion pulselessness from normal cardiac pulsation and off-body measurements with macro average precision and recall of 0.978 and 0.972, respectively. This model was able to identify 93.7% of pulseless states (i.e., resembling a cardiac arrest event), with a 0.4% false positive rate. All classification models relied on a combination of time-, power spectral density (PSD)-, and frequency-domain features to differentiate normal cardiac pulsation, pulseless cardiac, and off-body PPG recordings. However, our best model represented an idealized detection condition, relying on ensuring high-quality PPG data for training and evaluation of machine learning algorithms. While 90.7% of our PPG recordings from the fingertip were considered of high quality, only 53.2% of the measurements from the wrist passed the quality criteria. Our findings have implications for adapting consumer wearables to provide OHCA detection, involving advancements in hardware and software to ensure high-quality measurements in real-world settings, as well as development of wearables with form factors that enable high-quality PPG data acquisition more consistently. Given these improvements, we demonstrate that OHCA detection can feasibly be made available to anyone using PPG-based consumer wearables.

Enhancing Bystander Intervention: Insights from the Utstein Analysis of Out-of-Hospital Cardiac Arrests in Slovenia.

Background and Objectives: Out-of-hospital cardiac arrest (OHCA) and survival is a pressing matter all around the world. Despite years of research and great strides and advancements, survival remains alarmingly low. The aim of this study was to measure the survival and characteristics of patients having an OHCA in Slovenia, with an in-depth look at how the bystanders affect the return of spontaneous circulation (ROSC) and survival of OHCA. Materials and Methods: In this observational cross-sectional prospective study, we enrolled patients between 1 September 2022 and 30 November 2022, with a follow-up period of 1 month. All OHCAs attended by the emergency medical services were included. Data were collected and analyzed according to the Utstein 2015 reporting template. Independent predictors of ROSC and 30-day survival or survival were explored using ridge regression. Results: ROSC was achieved in 41% of cases where resuscitation was attempted. The overall 30-day survival rate where resuscitation was attempted was 14%. In 13% of all cases where resuscitation was attempted, patients had a favorable neurological outcome. Using our prediction model, we found that defibrillation under 20 min and ventricular fibrillation as an initial rhythm improves survival, whilst no defibrillation and bystander full cardiopulmonary resuscitation negatively predicted survival. Conclusions: Slovenia has OHCA 30-day survival comparable to the rest of the European Union. The favorable neurological outcome is high. Our data show that bystanders do not significantly improve survival. This represents an untapped potential of general public education in cardiopulmonary resuscitation and automatic external defibrillator use. Following good practices from abroad and improving layperson CPR knowledge could further improve OHCA survival.

Impact of community-based interventions on out-of-hospital cardiac arrest outcomes: a systematic review and meta-analysis

Survival following out-of-hospital cardiac arrest (OHCA) remains low, typically less than 10%. Bystander cardiopulmonary resuscitation (CPR) and bystander-AED use have been shown to improve survival by up to fourfold in individual studies. Numerous community-based interventions have been implemented worldwide in an effort to enhance rates of bystander-CPR, bystander-AED use, and improve OHCA survival. This systematic review and meta-analysis aims to evaluate the effect of such interventions on OHCA outcomes. Medline and Embase were systematically searched from inception through July 2021 for studies describing the implementation and effect of one or more community-based interventions targeting OHCA outcomes. Two reviewers screened articles, extracted data, and evaluated study quality using the Newcastle–Ottawa Scale. For each outcome, data were pooled using random-effects meta-analysis. Of the 2481 studies identified, 16 met inclusion criteria. All included studies were observational. They reported a total of 1,081,040 OHCAs across 11 countries. The most common interventions included community-based CPR training (n = 12), community-based AED training (n = 9), and dispatcher-assisted CPR (n = 8). Health system interventions (hospital or paramedical services) were also described in 11 of the included studies. Evidence certainty among all outcomes was low or very low according to GRADE criteria. On meta-analysis, community-based interventions with and without health system interventions were consistently associated with improved OCHA outcomes: rates of bystander-CPR, bystander-AED use, survival, and survival with a favorable neurological outcome. Bystander CPR—14 studies showed a significant increase in post-intervention bystander-CPR rates (n = 285 752; OR 2.26 [1.74, 2.94]; I2 = 99%, and bystander AED use (n = 37 882; OR 2.08 [1.44, 3.01]; I2 = 54%) and durvival—10 studies, pooling survival to hospital discharge and survival to 30 days (n = 79 206; OR 1.59 [1.20, 2.10]; I2 = 95%. The results provide foundational support for the efficacy of community-based interventions in enhancing OHCA outcomes. These findings inform our recommendation that communities, regions, and countries should implement community-based interventions in their pre-hospital strategy for OHCA. Further research is needed to identify which specific intervention types are most effective.

Out-of-hospital cardiac arrests in the city of Cape Town metropole of the Western Cape province of South Africa: a spatio-temporal analysis.

The incidence of out-of-hospital cardiac arrest (OHCA) is expected to increase in sub-Saharan Africa along with the incidence of cardiovascular disease. In low-resource settings (LRS), OHCA carries a negligible survival rate. Interventions to improve OHCA survival might not be cost effective for many LRS, and therefore need to be targeted to areas of high incidence. The aim of this study was to describe the temporal and geographic distribution of OHCA in the City of Cape Town, South Africa, and their proximity to percutaneous coronary intervention (PCI) resources. In this retrospective study, OHCA data between 1 January and 31 December 2018 were extracted from public and one private emergency medical services in the Western Cape. For temporal analysis, distribution of OHCA according to time of day, day of the week and month of the year were subjected to chi-squared testing. For geospatial analysis, cluster and outlier, and hotspot analyses were performed. Proximity analysis was employed to determine the driving time from OHCA location to the closest PCI-capable facility. A total of 929 patients with OHCA received an emergency medical services response in the City of Cape Town, corresponding to an annual prevalence of 23.2 per 100 000 persons. The distribution of OHCA incidence was not explained by month of the year (p = 0.08) or day of the week (p = 0.67). A statistically significant variation in OHCA incidence was explained by time of day (p < 0.01) with 30% (n = 279) of all OHCAs occurring from 05:00 to 09:59. Geospatial analysis yielded a large area of hotspots (99% confidence interval) over the centre of the metropole, Cape Flats and southern suburbs. The median (interquartile range) driving time from the incident to the closest PCI-capable facility was 10:22 (08:05) minutes. Incidents of OHCA occurred predominantly at home during the mid-morning, with hotspots around the city centre and residential suburbs of Cape Town. While the incidents occurred close to PCI-capable facilities, some areas remained underserved and access to PCI for OHCA victims may be impossible due to socio-economic factors. With an increase in OHCA incidence expected, it is essential that contextual, cost-effective management interventions be developed and implemented.

Utilizing community level factors to improve prediction of out of hospital cardiac arrest outcome using machine learning

ObjectivesTo evaluate the impact of community level information on the predictability of out-of-hospital cardiac arrest (OHCA) survival. MethodsWe used the Cardiac Arrest Registry to Enhance Survival (CARES) to geocode 9,595 Chicago incidents from 2014 to 2019 into community areas. Community variables including crime, healthcare, and economic factors from public data were merged with CARES. The merged data were used to develop ML models for OHCA survival. Models were evaluated using Area Under the Receiver Operating Characteristic curve (AUROC) and features were analyzed using SHapley Additive exPansion (SHAP) values. ResultsBaseline results using CARES data achieved an AUROC of 84%. The final model utilizing community variables increased the AUROC to 88%. A SHAP analysis between high and low performing community area clusters showed the high performing cluster is positively impacted by good health related features and good community safety features positively impact the low performing cluster. ConclusionUtilizing community variables helps predict neurologic outcomes with better performance than only CARES data. Future studies will use this model to perform simulations to identify interventions to improve OHCA survival.

Variation in Out-of-Hospital Cardiac Arrest Survival Across Emergency Medical Service Agencies.

Although studies have reported variation in out-of-hospital cardiac arrest (OHCA) survival by geographic location, little is known about variation in OHCA survival at the level of emergency medical service (EMS) agencies-which may have modifiable practices, unlike counties and regions. We quantified the variation in OHCA survival across EMS agencies and explored whether variation in 2 specific EMS resuscitation practices were associated with survival to hospital admission. Within the Cardiac Arrest Registry to Enhance Survival, a prospective registry representing ≈51% of the US population, we identified 258 342 OHCAs from 764 EMS agencies with >10 OHCA cases annually during 2015 to 2019. Using hierarchical logistic regression, risk-standardized rates of survival to hospital admission were computed for each EMS agency. We quantified inter-agency variation in survival with median odds ratios and assessed the association of 2 resuscitation practices (EMS response time and the proportion of OHCAs with termination of resuscitation without meeting futility criteria) with EMS agency survival rates to hospital admission. Across 764 EMS agencies comprising 258 342 OHCAs, the median risk-standardized rate of survival to hospital admission was 27.3% (interquartile range, 24.5%-30.1%; range: 16.0%-45.6%). The adjusted median odds ratio was 1.35 (95% CI, 1.32-1.39), denoting that the odds of survival of 2 patients with identical covariates varied by 35% at 2 randomly selected EMS agencies. EMS agencies in the lowest quartile of risk-standardized survival had longer EMS response times when compared with the highest quartile (12.0±3.4 versus 9.0±2.6 minutes; P<0.001), and a higher proportion of OHCAs with termination of resuscitation without meeting futility criteria (27.9±16.1% versus 18.9±11.4%; P<0.001). Survival after OHCA varies widely across EMS agencies. EMS response times and termination of resuscitation practices were associated with agency-level rates of survival to hospital admission, suggesting potentially modifiable practices which can improve OHCA survival.

A spatiotemporal data mining study to identify high-risk neighborhoods for out-of-hospital cardiac arrest (OHCA) incidents

Out-of-hospital cardiac arrest (OHCA) is a worldwide health problem. The aim of the study is to utilize the territorial-wide OHCA data of Hong Kong in 2012–2015 to examine its spatiotemporal pattern and high-risk neighborhoods. Three techniques for spatiotemporal data mining (SaTScan’s spatial scan statistic, Local Moran’s I, and Getis Ord Gi*) were used to extract high-risk neighborhoods of OHCA occurrence and identify local clusters/hotspots. By capitalizing on the strengths of these methods, the results were then triangulated to reveal “truly” high-risk OHCA clusters. The final clusters for all ages and the elderly 65+ groups exhibited relatively similar patterns. All ages groups were mainly distributed in the urbanized neighborhoods throughout Kowloon. More diverse distribution primarily in less accessible areas was observed among the elderly group. All outcomes were further converted into an index for easy interpretation by the general public. Noticing the spatial mismatches between hospitals and ambulance depots (representing supplies) and high-risk neighborhoods (representing demands), this setback should be addressed along with public education and strategic ambulance deployment plan to shorten response time and improve OHCA survival rate. This study offers policymakers and EMS providers essential spatial evidence to assist with emergency healthcare planning and informed decision-making.

Maximum expected survival rate model for public access defibrillator placement

AimMathematical optimization of automated external defibrillator (AED) placement has demonstrated potential to improve survival of out-of-hospital cardiac arrest (OHCA). Existing models mostly aim to improve accessibility based on coverage radius and do not account for detailed impact of delayed defibrillation on survival. We aimed to predict OHCA survival based on time to defibrillation and developed an AED placement model to directly maximize the expected survival rate. MethodsWe stratified OHCAs occurring in Singapore (2010–2017) based on time to defibrillation and developed a regression model to predict the Utstein survival rate. We then developed a novel AED placement model, the maximum expected survival rate (MESR) model. We compared the performance of MESR with a maximum coverage model developed for Canada that was shown to be generalizable to other settings (Denmark). The survival gain of MESR was assessed through 10-fold cross-validation for placement of 20 to 1000 new AEDs in Singapore. Statistical analysis was performed using χ2 and McNemar’s tests. ResultsDuring the study period, 15,345 OHCAs occurred. The power-law approximation with R2 of 91.33% performed best among investigated models. It predicted a survival of 54.9% with defibrillation within the first two minutes after collapse that was reduced by more than 60% without defibrillation within the first 4 minutes. MESR outperformed the maximum coverage model with P-value < 0.05 (<0.0001 in 22 of 30 experiments). ConclusionWe developed a novel AED placement model based on the impact of time to defibrillation on OHCA outcomes. Mathematical optimization can improve OHCA survival.

The impact of bystander cardiopulmonary resuscitation on patients with out-of-hospital cardiac arrests.

Out-of-hospital cardiac arrest (OHCA) is one of the leading causes of death around the world. Bystander cardiopulmonary resuscitation (CPR) is an independent factor to improve OHCA survival. However, the prevalence of bystander CPR remains low worldwide. Community interventions such as mandatory school CPR training or targeting CPR training to family members of high-risk cardiac patients are possible strategies to improve bystander CPR rate. Real-time feedback, hands-on practice with a manikin, and metronome assistance may increase the quality of CPR. Dispatcher-assistance and compression-only CPR for untrained bystanders have shown to increase bystander CPR rate and increase survival to hospital discharge. After return of spontaneous circulation, targeted temperature management should be performed to improve neurological function. This review focuses on the impact of bystander CPR on clinical outcomes and strategies to optimize the prevalence and quality of bystander CPR.

Abstract 12639: The Disparities of Gender-Based Out of Hospital Cardiac Arrest Characteristics and Outcomes: Comparing Rural to Urban Vancouver Island

Introduction: The relationship between the “chain of survival” metrics of Out of Hospital Cardiac Arrest (OHCA) and survival rates in rural settings has not been fully examined. In previous studies, low survival rate was attributable to the modifiable prehospital metrics and Return Of Spontaneous Circulation (ROSC). Hypothesis: Gender-based disparities in the modifiable and non-modifiable OHCA characteristics and outcomes are significant between rural and urban settings. Methods: We did a post-hoc analyses of data from the British Columbia cardiac arrest registry, which enrolled all emergency medical system (EMS)-treated OHCAs. All non-EMS-witnessed OHCAs on Vancouver Island from Jan. 2019 to Oct. 2020 were included. The independent variable of interest was rural versus urban settings. Rural areas were defined as all areas outside the urban clusters (population ≥ 1000 and a population density of ≥ 400/km2). Our outcomes were 1. Post resuscitation ROSC, and 2. Survival to hospital discharge. We reported gender-mediated measures and adjusted odds ratios using logistic regression models. Results: We included 1172 OHCA patients, with 23% in rural settings, 33% female, 30% had ROSC, and 23% survived to hospital discharge. The median EMS response time, from 911-call to first EMS arrival, was prolonged [10.5 mins (IQR 7.5-15)] in rural settings compared to urban settings [6.5 mins (IQR 5-9)] (p value&lt;.001). Among females, rural settings were associated with higher odds of bystander CPR compared to males [(OR 1.86; 95% CI 1.04-3.35), (OR 1.42; 95% CI 0.95-2.13)], respectively. After adjusting for all covariates, rural settings were associated with lower odds of ROSC among males compared to females [(OR 0.53; 95% CI 0.31-0.90), (OR 0.70; 95% CI 0.34-1.41)], respectively; however, not associated with survival to hospital discharge. Conclusions: There are significant disparities in the modifiable prehospital OHCA characteristics, and post resuscitation ROSC between rural and urban Vancouver Island. An officially integrated rural CPR community-based program, and innovations focused on gender-based implementation may significantly improve OHCA survival rates and subsequent prognostication.

Abstract 12494: The Disparities of Gender-Based Out of Hospital Cardiac Arrest Characteristics and Outcomes: Comparing Rural to Urban Vancouver Island

Introduction: The relationship between the “chain of survival” metrics of Out of Hospital Cardiac Arrest (OHCA) and survival rates in rural settings has not been fully examined. In previous studies, low survival rate was attributable to the modifiable prehospital metrics and Return Of Spontaneous Circulation (ROSC). We sought to examine the association of the modifiable and non-modifiable OHCA characteristics and patient outcomes with rural settings. Methods: We did a post-hoc analyses of data from the British Columbia cardiac arrest registry, which enrolled all emergency medical system (EMS)-treated OHCAs. All non-EMS-witnessed OHCAs on Vancouver Island from Jan. 2019 to Oct. 2020 were included. The independent variable of interest was rural versus urban settings. Rural areas were defined as all areas outside the urban clusters (population ≥ 1000 and a population density of ≥ 400/km2). Our outcomes were 1. Post resuscitation ROSC, and 2. Survival to hospital discharge. We reported gender-mediated measures and adjusted odds ratios using logistic regression models. Results: We included 1172 OHCA patients, with 23% in rural settings, 33% Female, 30% had ROSC, and 23% survived to hospital discharge. The median EMS response time, from 911-call to first EMS arrival, was prolonged [10.5 mins (IQR 7.5-15)] in rural settings compared to urban settings [6.5 mins (IQR 5-9)] (p value&lt;.001) . Among females, rural settings were associated with higher odds of bystander CPR compared to males [(OR 1.86; 95% CI 1.04-3.35), (OR 1.42; 95% CI 0.95-2.13)], respectively. After adjusting for all covariates, rural settings were associated with lower odds of ROSC among males compared to females [(OR 0.53; 95% CI 0.31-0.90), (OR 0.70; 95% CI 0.34-1.41)], respectively; however, not associated with survival to hospital discharge. Conclusions: There are significant disparities in the modifiable prehospital OHCA characteristics, and post resuscitation ROSC between rural and urban Vancouver Island. An officially integrated rural CPR community-based program, and innovations focused on gender-based implementation may significantly improve OHCA survival rates and subsequent prognostication.

Time to amiodarone administration and survival outcomes in refractory ventricular fibrillation.

International guidelines recommend amiodarone for out-of-hospital cardiac arrest (OHCA) in refractory ventricular fibrillation (VF). While early appropriate interventions have been shown to improve OHCA survival, the association between time to amiodarone and survival remains to be established. Included were adult OHCA in refractory VF, between January 2015 and December 2019, who received a resuscitation attempt with amiodarone from Queensland Ambulance Service paramedics. Patient characteristics and survival outcomes were described. Factors associated with survival were investigated, with a focus on time from arrest to amiodarone administration. Optimal time window for amiodarone administration was determined, and factors influencing whether amiodarone was given within the optimal time window were examined. A total of 502 patients were included. The average (range) time from arrest to amiodarone was 25 (4-83) min. Time to amiodarone was negatively associated with survival (adjusted odds ratio 0.93 for event survival; 95% confidence interval 0.89-0.97). The optimal time window for amiodarone was within 23 min following arrest. Patients receiving amiodarone within the optimal time had significantly better survival than those receiving it outside this window (event survival 38.3% vs 20.6%, P < 0.001; discharge survival 25.5% vs 9.7%, P < 0.001; 30-day survival 25.1% vs 9.7%, P < 0.001). Paramedic response time (adjusted odds ratio 0.96; 95% confidence interval 0.92-0.99) and time from arrest to intravenous access (0.71; 0.67-0.76) were independent factors determining whether patients received amiodarone within the optimal time. Earlier amiodarone administration was associated with improved survival. Strategies aimed at reducing delay to amiodarone administration have the potential to improve outcome.

Activation of citizen responders to out-of-hospital cardiac arrest.

To discuss different approaches to citizen responder activation and possible future solutions for improved citizen engagement in out-of-hospital cardiac arrest (OHCA) resuscitation. Activating volunteer citizens to OHCA has the potential to improve OHCA survival by increasing bystander cardiopulmonary resuscitation (CPR) and early defibrillation. Accordingly, citizen responder systems have become widespread in numerous countries despite very limited evidence of their effect on survival or cost-effectiveness. To date, only one randomized trial has investigated the effect of citizen responder activation for which the outcome was bystander CPR. Recent publications are of observational nature with high risk of bias. A scoping review published in 2020 provided an overview of available citizen responder systems and their differences in who, when, and how to activate volunteer citizens. These differences are further discussed in this review. Implementation of citizen responder programs holds the potential to improve bystander intervention in OHCA, with advancing technology offering new improvement possibilities. Information on how to best activate citizen responders as well as the effect on survival following OHCA is warranted to evaluate the cost-effectiveness of citizen responder programs.

OHCA survey in Lombardy: comparison between years 2014 and 2019 (pre COVID-19).

Background and aim:The incidence of Out of Hospital Cardiac Arrest (OHCA) is estimated at 1/1000 persons/year. In the pre-Covid-19 era world, OHCA survival rate in Europe was 7-6%. The main objective is to analyze OHCA survival in the Lombardy region by highlighting the factors related to both the victims’ characteristics and the chain of survival.Methods:All OHCAs were grouped into four pre-established periods in 2019 (14-23 January; 15-24 April; 15-24 July; 14-23 October). Following the Utstein method, we selected witnessed OHCAs with presumed cardiac etiology. The outcome of each case was collected in four moments in time: Return of spontaneous circulation (ROSC), Emergency Department (ED), 24 hours and 30 days. The neurological outcome 30 days after OHCA was also investigated and stratified with the Cerebral Performance Category Score (CPC).Results:We selected 456 cases of OHCA with witnessed cardiac etiology. ROSC was achieved in 121 cases (26.5%), survival in the Emergency Departments in 110 patients (24.1%), after 24 hours in 86 (18.86%) and after 30 days in 72 (15.8%). Male sex was shown to improve OHCA survival. A shockable presentation rhythm, Cardiopulmonary Resuscitation (CPR) performed by bystanders and the activation of Public Access Defibrillation (PAD) positively influenced OHCA outcome.Conclusions:Males are more predisposed to incur an OHCA event than females, but they have greater chances of survival. Factors most related to survival are: shockable rhythm, bystanders CPR and the activation of a PAD. (www.actabiomedica.it)

Abstract 256: Outcome Prediction of Out of Hospital Cardiac Arrest with Environmental Information Using Machine Learning

Background: The lethality of out-of-hospital cardiac arrest (OHCA) among minority and low income patients in large urban centers has been extensively described. Neighborhood disparities in OHCA survival outcomes cannot be fully explained by clinical variables alone. Machine Learning (ML) is a sub-field of Artificial Intelligence where algorithms can learn and improve themselves by studying high volumes of data and evaluating interactions that affect OHCA. We sought to determine whether incorporating neighborhood variables into a ML model of OHCA can increase its predictive accuracy of survival outcomes. Methods: Using OHCA data from the Cardiac Arrest Registry to Enhance Survival (CARES) database, we geocoded Chicago incidents that occurred outside of healthcare facilities and nursing homes from 2014 - 2019 into the 77 Chicago community areas. Neighborhood characteristics (e.g., access to healthcare, educational attainment, crime rates) were assigned to OHCA cases based on community area using publicly available data from the Chicago Health Atlas (CHA). The merged CARES and CHA data were used to train, validate, test, and analyze ML models for OHCA survival outcomes, defined as a binary outcome based on Cerebral Performance Category or CPC (Good = CPC 1 or 2; Poor=CPC 3, 4, or 5). ML models including deep neural networks were developed and compared using average class sensitivity to models developed using only CARES data. Results: ML algorithms were tested on 9,595 cases of OHCA. Baseline results using only CARES data on the Embedded Fully Convolutional Network (EFCN) show an average class sensitivity of 84%. Including neighborhood variables from the CHA dataset increased the average class sensitivity of the EFCN model to 86.5-86.9%. Conclusion: The use of neighborhood variables in combination with CARES data can predict neurologic outcomes with a higher level of accuracy than using CARES registry data alone. Future studies will use this newly developed model to perform simulation experiments to identify neighborhood level interventions to improve OHCA survival outcomes.

An accessibility spatial search algorithm to optimize defibrillator deployment in indoor space

ABSTRACT Indoor space, where humans spend 80% of their lives, is subject to frequent out-of-hospital cardiac arrest (OHCA). Optimizing the spatial deployment of automated external defibrillators (AEDs) has the potential to improve OHCA survival rate. Complex indoor space is typically divided by hard barriers into multiple discrete subspaces across floors. Commonly used distance measurements, such as Euclidean distance and network distance, are unsuitable for indoor AED deployment. Instead, we propose an accessibility spatial search algorithm (ASSA) to generate accessible areas of candidate facilities, i.e. AEDs, based on an indoor space model, and optimizes the facility deployment subject to three objectives: maximizing the survival rate, maximizing total spatial coverage and maximizing backup coverage. Additionally, improved artificial bee colony (ABC) algorithm is used to solve the optimization problem. We design experiments with simulated and real-world scenarios for AED placements and evaluate the ASSA results. The experiments show that the ASSA can provide helpful guidance in optimizing AED placement in indoor space.

Community lessons to understand resuscitation excellence (culture): Association between emergency medical services (EMS) culture and outcome after out-of-hospital cardiac arrest

BackgroundThe large geographic variation in outcome after out-of-hospital cardiac arrest (OHCA) is not well explained by traditional patient and emergency medical services (EMS) characteristics. A ‘culture of excellence’ in resuscitation within an EMS is believed to be an important factor that influences quality of care and outcome in patients with OHCA. However, whether a culture of excellence is associated with improved survival after OHCA is not known. MethodologyWe linked survey responses from EMS agency medical directors related to resuscitation culture to a retrospective analysis of prospectively collected data from the Resuscitation Outcomes Consortium (ROC) Epistry – Cardiac Arrest. We used a multivariable random effects model to assess whether EMS culture strategies were associated with OHCA survival to hospital discharge. ResultsOf the 46 EMS medical directors surveyed, 35 (76%) provided a complete response. Included were n = 66,597 cases of OHCA who received attempted resuscitation by one of n = 123 EMS agencies from July 1, 2010, through June 30, 2015. Overall survival to discharge was 11%. Organizational values and goals were independently associated with survival to hospital discharge in all OHCAs (adjusted odds ratio [AOR] 1.27, 95% confidence interval [CI] 1.09−1.48) and the subgroup restricted to bystander witnessed OHCAs with initial shockable rhythm (AOR 1.55, 95% CI 1.21−1.99). ConclusionsAn organizational goal to improve OHCA survival was independently associated with improved survival to discharge. EMS agencies looking to improve OHCA survival should consider implementing an organizational goal to improve OHCA survival and empower quality improvement personnel to drive that goal.

Abstract 273: Exploring the Role of the Emergency Medical System in Promoting Bystander Cardiopulmonary Resuscitation During Out-of-hospital Cardiac Arrests

Introduction: Early bystander initiated cardiopulmonary resuscitation (BCPR) is a key link in the cardiac arrest chain of survival. Prior work indicates that BCPR has a greater impact on survival outcomes when arrests are witnessed, and bystanders are actively prepared. This study explores the role of the emergency medical system—including dispatch, police, fire, and emergency medical services (EMS), in promoting timely bystander response during an out-of-hospital cardiac arrest (OHCA) event. Methods: This sequential mixed-methods study used 2014-2017 data from the Michigan Cardiac Arrest Registry to Enhance Survival (MI-CARES) to analyze the effect of BCPR on OHCA survival outcomes. Logistic regression models were used to analyze the effect of BCPR on sustained ROSC with pulse upon emergency department (ED) arrival and secondary outcomes. These data were supplemented with semi-structured key informant interviews and multidisciplinary focus groups conducted during site visits to 9 emergency medical systems across Michigan including dispatch, police, fire, EMS, and ED. Results: A total of 21,044 OHCA incidents met inclusion criteria. OHCA patients who received BCPR had 1.32 times higher odds of achieving ROSC with pulse upon ED arrival than those that did not after multivariable adjustment (Table 1). Qualitative data from interviews suggest that emergency medical systems can play a critical role in promoting BCPR. Several salient themes emerged across stakeholders including: 1) Preparing the community for proactive bystander response through educational campaigns; 2) Facilitating BCPR during an event through dispatch-assisted CPR and on-scene responders providing positive reinforcement to bystanders; and 3) Reinforcing the importance of performing bystander CPR to the involved community after post arrest care. Conclusion: We found that BCPR was associated with statistically significant improvements in survival outcomes compared to those that did not receive BCPR. These findings emphasize the importance of training bystanders to initiate and perform CPR, and points to engaging the emergency medical system as a leader for this initiative to improve OHCA survival across US communities.

Getting R-AEDI to save lives in Singapore.

Early cardiopulmonary resuscitation (CPR) and defibrillation prior to the arrival of emergency medical services can improve survival from out-of-hospital cardiac arrest (OHCA) with good neurological outcome. However, the rate of local bystander CPR is only 24.3% and bystander defibrillation 2.1%. In 2015, the R-AEDI (Registry for AED Integration) initiative was started to improve OHCA survival rates. R-AEDI alerts volunteers to nearby OHCA cases via the myResponder mobile application. In 2015-2017, 7,682 AEDs were mapped and made accessible via this app. Comprehensive site inspections also resulted in fewer non-functional AEDs, as AED owners were educated on the importance of the maintenance of pads and batteries. The AED heat map allows us to identify areas that are lacking in or require improved public access AED coverage. The online AED registry found in the myResponder app is useful to locate AEDs rapidly during OHCAs. More community education would improve the rate of bystander defibrillation.