Effect of national implementation of utstein recommendation from the global resuscitation alliance on ten steps to improve outcomes from Out-of-Hospital cardiac arrest: a ten-year observational study in Korea

The development history, current state, challenges, and future directions of the BASIC-OHCA registry in China: A narrative review

Out-of-hospital cardiac arrest is a major public health problem worldwide due to its high burden and poor outcomes. Despite progress in treatment, patient outcomes remain unsatisfactory, particularly in low-resource settings. The establishment of a registry is the first step towards gaining a comprehensive understanding of prevailing local conditions and identifying potential opportunities for improving patient survival. Here, we provide a narrative review of the BASeline Investigation of Out-of-hospital Cardiac Arrest (BASIC-OHCA), the first national OHCA registry in China, to introduce its development history, current state, challenges and future directions. We aim to enhance cross-cultural understanding by providing insights from China, while also serving as a reference for the implementation of large-scale registries in low-resource settings.

Establishing the Korean Out-of-Hospital cardiac arrest registry (KOHCAR)

Background

The Korean out-of-hospital cardiac arrest registry (KOHCAR) serves as the basis for a chain of survival monitoring and quality improvement programs for out-of-hospital cardiac arrest (OHCA). This study describes the development history and current status of KOHCAR.

Methods/design

The KOHCAR, initiated in 2008, is a population-based OHCA registry that captures all emergency medical service (EMS)-assessed OHCA cases, regardless of etiology. The KOHCAR represents complete nationwide data and aligns with South Korea's comprehensive plan for cardiovascular disease, which has a legal basis. The KOHCAR is a collaboration between the National Fire Agency (NFA) and the Korea Disease Control and Prevention Agency (KDCA). The NFA identifies OHCA patients and provides prehospital information after integrating various EMS records, whereas the KDCA collects hospital information and clinical outcomes through a medical record review. Comprehensive Utstein variables, including patient and arrest characteristics, prehospital and hospital management, and survival outcomes, were collected.

Discussion

The KOHCAR has significantly contributed to improving OHCA survival rates in South Korea; however, the COVID-19 pandemic has posed challenge. To address the post-pandemic survival rate decline, there is a need to enhance data utilization, expand data sources, and tailor communication with diverse stakeholders.

The Lancet Commission to reduce the global burden of sudden cardiac death: a call for multidisciplinary action

Despite major advancements in cardiovascular medicine, sudden cardiac death (SCD) continues to be an enormous medical and societal challenge, claiming millions of lives every year. Efforts to prevent SCD are hampered by imperfect risk prediction and inadequate solutions to specifically address arrhythmogenesis. Although resuscitation strategies have witnessed substantial evolution, there is a need to strengthen the organisation of community interventions and emergency medical systems across varied locations and health-care structures. With all the technological and medical advances of the 21st century, the fact that survival from sudden cardiac arrest (SCA) remains lower than 10% in most parts of the world is unacceptable. Recognising this urgent need, the Lancet Commission on SCD was constituted, bringing together 30 international experts in varied disciplines. Consistent progress in tackling SCD will require a completely revamped approach to SCD prevention, with wide-sweeping policy changes that will empower the development of both governmental and community-based programmes to maximise survival from SCA, and to comprehensively attend to survivors and decedents' families after the event. International collaborative efforts that maximally leverage and connect the expertise of various research organisations will need to be prioritised to properly address identified gaps. The Commission places substantial emphasis on the need to develop a multidisciplinary strategy that encompasses all aspects of SCD prevention and treatment. The Commission provides a critical assessment of the current scientific efforts in the field, and puts forth key recommendations to challenge, activate, and intensify efforts by both the scientific and global community with new directions, research, and innovation to reduce the burden of SCD worldwide.

Interaction between Bystander Sex and Patient Sex in Bystander Cardiopulmonary Resuscitation for Out-of-Hospital Cardiac Arrests

BACKGROUND

Bystander cardiopulmonary resuscitation (CPR) is a critical factor in improving out-of-hospital cardiac arrest (OHCA) survival. The aim of this study was to investigate the interaction effect of bystander sex and patient sex on the provision of bystander CPR.

METHODS

This was a retrospective cohort study using national OHCA registry in Korea. The inclusion criteria were adult bystander-witnessed OHCA patients with presumed cardiac etiology from January 2016 to December 2020. The primary outcome was the provision of bystander CPR. Multivariable logistic regression and interaction analysis were conducted to evaluate the impact of bystander sex on bystander CPR provision based on patient sex.

RESULTS

The study included 24,919 patients with OHCA, 58.2% with male-bystanders and 41.8% with female-bystanders. Female bystanders were less likely to perform bystander CPR than male bystanders (68.0% vs. 78.8%, adjusted OR (95% CI): 0.62 (0.58-0.66)). Among patients with CPR-trained bystanders, female bystanders had lower odds of bystander CPR (0.85 (0.73-0.97)). In the interaction analysis between bystander and patient sex, a significant difference was observed in the likelihood of bystander CPR according to the patient sex. Female bystanders had lower odds of bystander CPR than male bystanders for male patients (0.47 (0.43-0.50)). However, there were no significant differences between male and female bystanders for female patients (0.91 (0.88-1.07)).

CONCLUSION

Female bystanders have a lower likelihood of providing bystander CPR than male bystanders. Additionally, an interaction was observed between bystander sex and patient sex in the providing bystander CPR, with the association being more pronounced in male OHCA patients.

Extracorporeal cardiopulmonary resuscitation for adult out-of-hospital cardiac arrest patients: time-dependent propensity score-sequential matching analysis from a nationwide population-based registry

BACKGROUND

There is inconclusive evidence regarding the effectiveness of extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA) patients. We aimed to evaluate the association between ECPR and neurologic recovery in OHCA patients using time-dependent propensity score matching analysis.

METHODS

Using a nationwide OHCA registry, adult medical OHCA patients who underwent CPR at the emergency department between 2013 and 2020 were included. The primary outcome was a good neurological recovery at discharge. Time-dependent propensity score matching was used to match patients who received ECPR to those at risk for ECPR within the same time interval. Risk ratios (RRs) and 95% confidence intervals (CIs) were estimated, and stratified analysis by the timing of ECPR was also performed.

RESULTS

Among 118,391 eligible patients, 484 received ECPR. After 1:4 time-dependent propensity score matching, 458 patients in the ECPR group and 1832 patients in the no ECPR group were included in the matched cohort. In the matched cohort, ECPR was not associated with good neurological recovery (10.3% in ECPR and 6.9% in no ECPR; RR [95% CI] 1.28 [0.85-1.93]). In the stratified analyses according to the timing of matching, ECPR with a pump-on within 45 min after emergency department arrival was associated with favourable neurological outcomes (RR [95% CI] 2.51 [1.33-4.75] in 1-30 min, 1.81 [1.11-2.93] in 31-45 min, 1.07 (0.56-2.04) in 46-60 min, and 0.45 (0.11-1.91) in over 60 min).

CONCLUSIONS

ECPR itself was not associated with good neurological recovery, but early ECPR was positively associated with good neurological recovery. Research on how to perform ECPR at an early stage and clinical trials to evaluate the effect of ECPR is warranted.

Impact of COVID-19 on Out-of-Hospital Cardiac Arrest in Korea

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a global public health crisis that has had a significant impact on emergency medical services (EMS). Several studies have reported an increase in the incidence of out-of-hospital cardiac arrest (OHCA) and a decreased survival due to COVID-19, which has been limited to a short period or has been reported in some regions. This study aimed to investigate the effect of COVID-19 on OHCA patients using a nationwide database.

METHODS

We included adult OHCA patients treated by EMS providers from January 19, 2019 to January 20, 2021. The years before and after the first confirmed case in Korea were set as the non-COVID-19 and COVID-19 periods, respectively. The main exposure of interest was the COVID-19 period, and the primary outcome was prehospital return of spontaneous circulation (ROSC). Other OHCA variables were compared before and after the COVID-19 pandemic and analyzed. We performed a multivariable logistic regression analysis to understand the independent effect of the COVID-19 period on prehospital ROSC.

RESULTS

The final analysis included 51,921 eligible patients, including 25,355 (48.8%) during the non-COVID-19 period and 26,566 (51.2%) during the COVID-19 period. Prehospital ROSC deteriorated during the COVID-19 period (10.2% vs. 11.1%, P = 0.001). In the main analysis, the adjusted odds ratios (AORs) for prehospital ROSC showed no significant differences between the COVID-19 and non-COVID-19 periods (AOR [95% confidence interval], 1.02 [0.96-1.09]).

CONCLUSION

This study found that the proportion of prehospital ROSC was lower during the COVID-19 period than during the non-COVID-19 period; however, there was no statistical significance when adjusting for potential confounders. Continuous efforts are needed to restore the broken chain of survival in the prehospital phase and increase the survival rate of OHCA patients.

The impact of COVID-19 pandemic on out-of-hospital cardiac arrest system-of-care: Which survival chain factor contributed the most?

OBJECTIVES

In many communities, out-of-hospital cardiac arrest (OHCA) survival outcomes decreased after the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to identify and compare the impacts of each survival chain factor on the change of survival outcomes after COVID-19.

METHODS

Using a Korean out-of-hospital cardiac arrest registry, we analyzed OHCA patients whose arrest was not witnessed by emergency medical service (EMS) providers between 2017 and 2021. Because lack of hospital and survival information in 2021, the 2021 data were used only to identify the expected trend. We developed a prediction model for survival to discharge using patients from 2017 to 2019 (Pre-COVID-19 set) and validated it using patients from 2020 (post-COVID-19 set). Using Utstein elements, a stepwise logistic regression model was constructed, and discrimination and calibration were evaluated by c-statistics and scaled Brier score. Using the distribution change of predictors from one year before the pandemic (2019) to post-COVDI-19, we calculated the magnitude of survival difference according to each predictor's distribution change using the marginal standardization method.

RESULTS

Among 83,273 patients (mean age 67.2 years and 64.3% males), 61,180 and 22,092 patients belonged to pre-COVOD-19 and post-COVID-19 sets. Survival to discharge was 5019 (8.2%) in pre-COVID-19 set and 1457 (6.6%) in post-COVID-19 set. The proportion of bystander cardiopulmonary resuscitation was 59.0% in the pre-COVID-19 set and 61.0% in the post-COVID-19 set. The median (interquartile range) response time was 7 (5-9) minutes in the pre-COVID-19 set and 8 (6-10) minutes in the post-COVID-19 set. The area under the receiver operating characteristic (AUROC) curve (95% confidence interval) was 0.907 (0.902-0.912) in the pre-COVID-19 set, and 0.924 (0.916-0.931) in the post-COVID-19 set, and scaled Brier score were 0.39 in pre-COVID-19 sets, and 0.40 in the post-COVID-19 set. Among various predictors, EMS factors showed the highest impact. Response time and on-scene management of EMS showed the highest impact on decreased survival. A similar trend was also expected in the 2021.

CONCLUSION

The effort to create a rapid response system for OHCA patients could have priority for the recovery of survival outcomes in OHCA patients in the post-COVID-19 period. Further studies to recover survival outcomes of OHCA are warranted.

Sex difference in the association between type of bystander CPR and clinical outcomes in patients with out of hospital cardiac arrest

Background

A recent study suggested that women with out-of-hospital cardiac arrest have a smaller survival benefit with bystander cardiopulmonary resuscitation than men. We evaluated whether this weaker association between bystander cardiopulmonary resuscitation and survival in women is related to dispatcher-assisted vs unassisted bystander cardiopulmonary resuscitation.

Methods

In a national registry in the Republic of Korea, we identified adult patients with out-of-hospital cardiac arrest during 2013-2018. The main exposure was type of bystander cardiopulmonary resuscitation (categorized as none, dispatcher-assisted, and unassisted). The primary outcome was favourable neurological survival. Multivariable logistic regression evaluated for an interaction between sex and type of bystander cardiopulmonary resuscitation.

Results

Of 93,245 patients with out-of-hospital cardiac arrest, there were 31,578 (33.9%) women and 61,667 (66.1%) men. Overall, both types of bystander cardiopulmonary resuscitation were associated with favourable neurological survival (unassisted: adjusted OR, 1.81 [95% CI: 1.66-1.98]; dispatcher-assisted: adjusted OR, 1.44 [95% CI: 1.33-1.56]). When unassisted cardiopulmonary resuscitation was administered, the association between bystander cardiopulmonary resuscitation and favourable neurological survival was similar between women and men: adjusted ORs of 1.59 (95% CI: 1.30-1.95) in women and 1.88 (95% CI: 1.71-2.08) in men; interaction p = 0.65). In contrast, when dispatcher-assisted cardiopulmonary resuscitation was administered, the association differed by sex: adjusted ORs of 1.08 (95% CI: 0.90-1.92) in women and 1.55 (95% CI: 1.42-1.69) in men; interaction p < 0.0002).

Conclusions

Dispatcher-assisted cardiopulmonary resuscitation was associated with favourable neurological survival in men but not in women whereas unassisted bystander cardiopulmonary resuscitation was associated with favourable neurological survival in women and men.

Machine Learning Analysis to Identify Data Entry Errors in Prehospital Patient Care Reports: A Case Study of a National Out-of-Hospital Cardiac Arrest Registry

Background: The objective of this study was to develop and validate machine learning models for data entry error detection in a national out-of-hospital cardiac arrest (OHCA) prehospital patient care report database.Methods: Adult OHCAs of presumed cardiac etiology were included. Data entry errors were defined as discrepancies between the coded data and the free-text note documenting the intervention or event; for example, information that was recorded as "absent" in the coded data but "present" in the free-text note. Machine learning models using the extreme gradient boosting, logistic regression, extreme gradient boosting outlier detection, and K-nearest neighbor outlier detection algorithms for error detection within nine core variables were developed and then validated for each variable.Results: Among 12,100 OHCAs, the proportion of cases with at least one error type was 16.2%. The area under the receiver operating characteristic curve (AUC) of the best-performing model (model with the highest AUC for each outcome variable) was 0.71-0.95. Machine learning models detected errors most efficiently for outcome place and initial rhythm errors; 82.6% of place errors and 93.8% of initial rhythm errors could be detected while checking 11 and 35% of data, respectively, compared to the strategy of checking all data.Conclusion: Machine learning models can detect data entry errors in care reports of emergency medical services (EMS) clinicians with acceptable performance and likely can improve the efficiency of the process of data quality control. EMS organizations that provide more prehospital interventions for OHCA patients could have higher error rates and may benefit from the adoption of error-detection models.

National Surveillance of Pediatric Out-of-Hospital Cardiac Arrest in Korea: The 10-Year Trend From 2009 to 2018

BACKGROUND

This study reports trends in pediatric out-of-hospital cardiac arrest (OHCA) and factors affecting clinical outcomes by age group.

METHODS

We identified 4,561 OHCA patients younger than 18 years between January 2009 and December 2018 in the Korean OHCA Registry. The patients were divided into four groups: group 1 (1 year or younger), group 2 (1 to 5 years), group 3 (6 to 12 years), and group 4 (13 to 17 years). The primary outcome was survival to hospital discharge, and the secondary outcomes were return of spontaneous circulation (ROSC) at the emergency department (ED) and good neurological status at discharge. Multivariate logistic analyses were performed.

RESULTS

The incidence rate of pediatric OHCA in group 1 increased from 45.57 to 60.89 per 100,000 person-years, while that of the overall population decreased over the 10 years. The rates of ROSC at the ED, survival to hospital discharge, and good neurologic outcome were highest in group 4 (37.9%, 9.7%, 4.9%, respectively) and lowest in group 1 (28.3%, 7.1%, 3.2%). The positive factors for survival to discharge were event location of a public/commercial building or place of recreation, type of first responder, prehospital delivery of automated external defibrillator shock, initial shockable rhythm at the ED. The factors affecting survival outcomes differed by age group.

CONCLUSION

This study reports comprehensive trends in pediatric OHCA in the Republic of Korea. Our findings imply that preventive methods for the targeted population should be customized by age group.

Effects of a designated ambulance team response on prehospital return of spontaneous circulation and advanced cardiac life support of out-of-hospital cardiac arrest: A nationwide natural experimental study

OBJECTIVES

This study aimed to investigate the effects of adding advanced cardiac life support (ACLS) training to an existing basic life support program and the operation of a designated team response for patients with out-of-hospital cardiac arrest (OHCA) on prehospital return of spontaneous circulation (ROSC) and ACLS management.

METHODS

A natural experimental study was conducted for emergency medical service (EMS)-treated adult patients with OHCA in 2020. In 2019, a quarter of the EMS clinicians were trained in a 3-day ACLS courses, and they were designated to be dispatched first in suspected OHCA. Some were dispatched only to major emergencies, such as OHCA and myocardial infarction (dedicated team), while others were dispatched to all emergencies with priority to major ones (non-dedicated team). The exposure was the ambulance response type: dedicated, no-dedicated, and basic teams (others). The primary outcome was prehospital ROSC. The secondary outcomes were prehospital ACLS (advanced airway management and intravenous access). A multivariable logistic regression analysis was conducted to investigate the effect of ambulance response type on study outcomes.

RESULTS

Among 23,512 eligible patients with OHCA, 54.8% (12,874) were treated by the basic team, 36.5% (8,580) by the non-dedicated ACLS team, and 8.8% (2,058) were treated by the dedicated ACLS team. Prehospital ROSC was greater for the designated team than for the basic team (dedicated ACLS team 13.8%, non-dedicated ACLS team 11.3%, and basic team 6.7%) (p <0.01). In the final logistic regression analysis, compared with the basic team, the designated ACLS team was associated with a higher probability of prehospital ROSC (AOR (95% CIs), 1.88 (1.68-2.09) compared to the non-dedicated ACLS team, and 2.46 (2.09-2.90) compared to the dedicated ACLS team), prehospital advanced airway management (1.72 (1.57-1.87) and 1.73 (1.48-2.03), respectively), and intravenous access (2.29 (2.16-2.43) and 2.76 (2.50-3.04), respectively).

CONCLUSION

Additional ACLS training and operation of a designated OHCA team response were associated with higher rates of prehospital ROSC and prehospital ACLS provision. However, further research is needed to find the optimal operation for EMS to improve survival outcomes.

Effect of Prehospital Epinephrine Use on Survival from Out-of-Hospital Cardiac Arrest and on Emergency Medical Services

This study was to identify the effect of epinephrine on the survival of out-of-hospital cardiac arrest (OHCA) patients and changes in prehospital emergency medical services (EMSs) after the introduction of prehospital epinephrine use by EMS providers. This was a retrospective observational study comparing two groups (epinephrine group and norepinephrine group). We used propensity score matching of the two groups and identified the association between outcome variables regarding survival and epinephrine use, controlling for confounding factors. The epinephrine group was 339 patients of a total 1943 study population. The survival-to-discharge rate and OR (95% CI) of the epinephrine group were 5.0% (p = 0.215) and 0.72 (0.43–1.21) in the total patient population and 4.7% (p = 0.699) and 1.15 (0.55–2.43) in the 1:1 propensity-matched population. The epinephrine group received more mechanical chest compression and had longer EMS response times and scene times than the norepinephrine group. Mechanical chest compression was a negative prognostic factor for survival to discharge and favorable neurological outcomes in the epinephrine group. The introduction of prehospital epinephrine use in OHCA patients yielded no evidence of improvement in survival to discharge and favorable neurological outcomes and adversely affected the practice of EMS providers, exacerbating the factors negatively associated with survival from OHCA.

Outcomes of Out-of-hospital Cardiac Arrests After a Decade of System-wide Initiatives Optimising Community Chain of Survival in Taipei City

OBJECTIVE

A strengthened chain of survival benefits patient outcomes after out-of-hospital cardiac arrest (OHCA).² Over the past decade, the Taipei Fire Department (TFD) has continuously implemented system-wide initiatives on this issue.We hypothesised that for adult, non-trauma OHCA patients, the bundle of these system-wide initiatives are associated with better outcomes.

METHODS

We conducted a registry-based, retrospective study to examine the association between consecutive system-level initiatives and OHCA survival on a two-yearly basis using trend analysis and multivariable logistic regression. The primary outcome was survival to hospital discharge (STHD) and favourable neurological status.

RESULTS

We analysed 18,076 cases from 2008 to 2017. The numbers of two-yearly cases of OHCA with resuscitation attempts from 2008 to 2017 were 3,576, 3,456, 3,822, 3,811, and 3,411. There was a significant trend of improved STHD (Two-fold) and favourable neurological outcome (Six-fold) over the past decade. Similar trends were observed in the shockable and non-shockable groups. Considering the first 2 years as baseline, the odds of STHD and favourable neurological status in the end of the initiatives increased significantly after adjusting for universally recognised predictors for OHCA survival.

CONCLUSION

For non-trauma adult OHCA in Taipei, continuous, multifaceted system-wide initiatives on the community chain of survival were associated with improved odds of STHD and favourable neurologic outcomes.

Impact of crowding in local ambulance demand on call-to-ambulance scene arrival in out-of-hospital cardiac arrest

BACKGROUND

Rapid emergency medical service (EMS) response is an important prognostic factor in out-of-hospital cardiac arrest (OHCA). This study aims to evaluate the association between local hourly EMS demand and ambulance response in OHCA.

METHODS

OHCA occurring in 24 districts of Seoul from 2013 to 2018 was analyzed. Hourly ambulance demand per ambulance in each local district of patient location at the hour of cardiac arrest was calculated as the crowding index. The crowding index was categorized according to quartiles (1Q: ≤0.43, 2Q: 0.44-0.67, 3Q: 0.68-0.99, 4Q: ≥1.0 calls/h\r/ambulance). The primary outcome was ambulance dispatched within 1 km of the OHCA scene. Multivariable logistic regression analysis was performed to test the association between the local hourly ambulance demand and outcomes.

RESULTS

A total of 26,479 patients were analyzed. The rate of ambulance dispatched within 1 km decreased according to the crowding quartile (1Q: 31.3%, 2Q: 30.0%, 3Q: 28.8%, and 4Q: 26.6%). Compared to 1Q, adjusted odds ratios (95% CIs) of dispatch distance within 1 km in 2Q, 3Q, and 4Q were 0.92 (0.86-0.99), 0.86 (0.80-0.94), and 0.77 (0.71-0.84), respectively.

CONCLUSION

Crowding in local ambulance demand was associated with less ambulance dispatched within 1 km and delayed response to the scene in OHCA. Strategies to mitigate and adjust to ambulance demand crowding may be considered for better EMS response performance.

Effects of pre-hospital re-arrest on outcomes based on transfer to a heart attack centre in patients with out-of-hospital cardiac arrest

AIM

We aimed to investigate the interaction effects between transfer to a heart attack centre [HAC] and prehospital re-arrest on the clinical outcomes of patients with out-of-hospital cardiac arrest [OHCA].

METHODS

We included adult patients with OHCA of presumed cardiac aetiology from January 2012 to December 2018. The main exposure variable was prehospital re-arrest, defined as recurrence of cardiac arrest with a loss of palpable pulse upon hospital arrival. The other exposure variable was the resuscitation capacity of the receiving hospital [HAC or Non-HAC]. The outcome variable was neurological recovery. A multivariable logistic regression was performed to determine the interaction effects.

RESULTS

The final analysis included 6935 patients. Of these, 21.9% (n = 1521) experienced prehospital re-arrest, whereas 41.3% (n = 2866) were transferred to a non-HAC. The prehospital re-arrest group associated with poor neurological recovery (adjusted odds ratio [AOR], 0.25; 95% confidence interval [CI], 0.21-0.29;). Transfer to an HAC had beneficial effects on neurological recovery (AOR, 3.40 [95% CI, 3.04-3.85]. In the interaction model, wherein prehospital re-arrest patients who were transferred to a non-HAC were used as reference, the AOR of prehospital re-arrest patients who were transferred to an HAC, non-re-arrest patients who were transferred to a non-HAC, and non-re-arrest patients who were transferred to a non-HAC was 2.41 (95% CI, 1.73-3.35), 3.09 (95% CI, 2.33-4.10), and 11.07 (95% CI, 8.40-14.59) respectively (interaction p = 0.001).

CONCLUSION

Transport to a heart attack centre was beneficial to the clinical outcomes of patients who achieved prehospital ROSC after OHCA. The magnitude of that benefit was significantly modified by whether prehospital re-arrest had occurred.

Use of Time-to-Event Analysis to Develop On-Scene Return of Spontaneous Circulation Prediction for Out-of-Hospital Cardiac Arrest Patients

STUDY OBJECTIVE

We aimed to train and validate the time to on-scene return of spontaneous circulation prediction models using time-to-event analysis among out-of-hospital cardiac arrest patients.

METHODS

Using a Korean population-based out-of-hospital cardiac arrest registry, we selected a total of 105,215 adults with presumed cardiac etiologies between 2013 and 2018. Patients from 2013 to 2017 and from 2018 were analyzed for training and test, respectively. We developed 4 time-to-event analyzing models (Cox proportional hazard [Cox], random survival forest, extreme gradient boosting survival, and DeepHit) and 4 classification models (logistic regression, random forest, extreme gradient boosting, and feedforward neural network). Patient characteristics and Utstein elements collected at the scene were used as predictors. Discrimination and calibration were evaluated by Harrell's C-index and integrated Brier score.

RESULTS

Among the 105,215 patients (mean age 70 years and 64% men), 86,314 and 18,901 patients belonged to the training and test sets, respectively. On-scene return of spontaneous circulation was achieved in 5,240 (6.1%) patients in the former set and 1,709 (9.0%) patients in the latter. The proportion of emergency medical services (EMS) management was higher and scene time interval longer in the latter. Median time from EMS scene arrival to on-scene return of spontaneous circulation was 8 minutes for both datasets. Classification models showed similar discrimination and poor calibration power compared to survival models; Cox showed high discrimination with the best calibration (C-index [95% confidence interval]: 0.873 [0.865 to 0.882]; integrated Brier score at 30 minutes: 0.060).

CONCLUSION

Incorporating time-to-event analysis could lead to improved performance in prediction models and contribute to personalized field EMS resuscitation decisions.

Out of hospital cardiac arrest: Past, present, and future

Advances in resuscitation following out-of-hospital cardiac arrest (OHCA) provide an opportunity to improve public health. This review reflects on past developments, present status, and future possibilities using the science-education-implementation framework of the Utstein Formula and the clinical framework of the links in the chain of survival. With the discovery of CPR and defibrillation in the mid 20th century, resuscitation developed a scientific construct for progress. Systems of emergency community response provided operational efficiency to treat OHCA. Contemporary resuscitation involves integrated interventions in the chain of survival: early recognition, early CPR, early defibrillation, expert and timely advanced life support and hospital care, and multidimensional rehabilitation. Implementation of scientific advances is especially challenging given the unexpected nature of OHCA, the need for time-sensitive interventions, and the substantial collective of stakeholders involved in the chain of survival. Systematic measurement provides the foundation to evaluate performance and guide implementation initiatives. For many systems, telecommunicator CPR and high-performance CPR by emergency professionals are accessible, near-term programs to improve OHCA outcome. Smart technologies that activate, coordinate, and/or coach community "volunteers" to accelerate early CPR and defibrillation have conceptual promise, though robust implementation has been achieved by only a handful of systems. Longer-term strategies may leverage technology to develop a high-fidelity "life-detector" or engineer and disseminate a specialized consumer defibrillator designed to bridge care until arrival of professional response.

European Resuscitation Council Guidelines 2021: Systems saving lives

The European Resuscitation Council (ERC) has produced these Systems Saving Lives guidelines, which are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. The topics covered include chain of survival, measuring performance of resuscitation, social media and smartphones apps for engaging community, European Restart a Heart Day, World Restart a Heart, KIDS SAVE LIVES campaign, lower-resource setting, European Resuscitation Academy and Global Resuscitation Alliance, early warning scores, rapid response systems, and medical emergency team, cardiac arrest centres and role of dispatcher.

Effects of telephone-assisted cardiopulmonary resuscitation on the sex disparity in provision of bystander cardiopulmonary resuscitation in public locations

PURPOSE

Telephone-assisted cardiopulmonary resuscitation (TA-CPR) is an effective community intervention to increase bystander CPR rates. This study evaluated the effect of TA-CPR on the provision of bystander CPR as a function of the patient's sex.

METHODS

Adult (aged ≥ 18 years) patients who collapsed in a public location between January 2013 and December 2017 and received emergency medical service (EMS) treatment for out-of-hospital cardiac arrest (OHCA) of presumed cardiac aetiology were included in the study. The main exposures were TA-CPR and the patients' sex. The primary outcome was the implementation of bystander CPR by laypersons. Multivariable logistic regression analysis was conducted, stratified based on the provision of TA-CPR, to examine the effect on bystander CPR according to patient sex.

RESULTS

In the final analysis, 15,840 patients with OHCAs were included. Patients who received TA-CPR accounted for 32.6% (5167/15,840) of the sample. Overall, 84.4% (814/964) of the women and 86.9% (3653/4203) of the men received bystander CPR in the TA-CPR group (P < 0.001). In the non-TA-CPR group, 40.5% (912/2252) of women and 47.3% (3653/8421) of men received bystander CPR (P < 0.001). In the multivariable logistic regression analysis, there was no significant difference in the odds ratio (OR) of bystander CPR according to patient sex in the TA-CPR group (adjusted OR [AOR], 0.83; 95% confidence interval [CI], 0.68-1.01). Women were less likely to receive bystander CPR if the bystanders are not directed by TA-CPR (AOR: 0.79; 95% CI, 0.70-0.87).

CONCLUSIONS

TA-CPR attenuated the sex disparity in bystander CPR provided in public places.

Developing a time-adaptive prediction model for out-of-hospital cardiac arrest: Results from a nationwide cohort study in Korea (Preprint)

Background

Out-of-hospital cardiac arrest (OHCA) is a serious public health issue, and predicting the prognosis of OHCA patients can assist clinicians in making decisions about the treatment of patients, use of hospital resources, or termination of resuscitation.

Objective

This study aimed to develop a time-adaptive conditional prediction model (TACOM) to predict clinical outcomes every minute.

Methods

We performed a retrospective observational study using data from the Korea OHCA Registry in South Korea. In this study, we excluded patients with trauma, those who experienced return of spontaneous circulation before arriving in the emergency department (ED), and those who did not receive cardiopulmonary resuscitation (CPR) in the ED. We selected patients who received CPR in the ED. To develop the time-adaptive prediction model, we organized the training data set as ongoing CPR patients by the minute. A total of 49,669 patients were divided into 39,602 subjects for training and 10,067 subjects for validation. We compared random forest, LightGBM, and artificial neural networks as the prediction model methods. Model performance was quantified using the prediction probability of the model, area under the receiver operating characteristic curve (AUROC), and area under the precision recall curve.

Results

Among the three algorithms, LightGBM showed the best performance. From 0 to 30 min, the AUROC of the TACOM for predicting good neurological outcomes ranged from 0.910 (95% CI 0.910-0.911) to 0.869 (95% CI 0.865-0.871), whereas that for survival to hospital discharge ranged from 0.800 (95% CI 0.797-0.800) to 0.734 (95% CI 0.736-0.740). The prediction probability of the TACOM showed similar flow with cohort data based on a comparison with the conventional model’s prediction probability.

Conclusions

The TACOM predicted the clinical outcome of OHCA patients per minute. This model for predicting patient outcomes by the minute can assist clinicians in making rational decisions for OHCA patients.

External validation of multimodal termination of resuscitation rules for out-of-hospital cardiac arrest patients in the COVID-19 era

BACKGROUND

Futile resuscitation for out-of-hospital cardiac arrest (OHCA) patients in the coronavirus disease (COVID)-19 era can lead to risk of disease transmission and unnecessary transport. Various existing basic or advanced life support (BLS or ALS, respectively) rules for the termination of resuscitation (TOR) have been derived and validated in North America and Asian countries. This study aimed to evaluate the external validation of these rules in predicting the survival outcomes of OHCA patients in the COVID-19 era.

METHODS

This was a multicenter observational study using the WinCOVID-19 Daegu registry data collected during February 18-March 31, 2020. The subjects were patients who showed cardiac arrest of presumed cardiac etiology. The outcomes of each rule were compared to the actual patient survival outcomes. The sensitivity, specificity, false positive value (FPV), and positive predictive value (PPV) of each TOR rule were evaluated.

RESULTS

In total, 170 of the 184 OHCA patients were eligible and evaluated. TOR was recommended for 122 patients based on the international basic life support termination of resuscitation (BLS-TOR) rule, which showed 85% specificity, 74% sensitivity, 0.8% FPV, and 99% PPV for predicting unfavorable survival outcomes. When the traditional BLS-TOR rules and KoCARC TOR rule II were applied to our registry, one patient met the TOR criteria but survived at hospital discharge. With regard to the FPV (upper limit of 95% confidence interval < 5%), specificity (100%), and PPV (> 99%) criteria, only the KoCARC TOR rule I, which included a combination of three factors including not being witnessed by emergency medical technicians, presenting with an asystole at the scene, and not experiencing prehospital shock delivery or return of spontaneous circulation, was found to be superior to all other TOR rules.

CONCLUSION

Among the previous nine BLS and ALS TOR rules, KoCARC TOR rule I was most suitable for predicting poor survival outcomes and showed improved diagnostic performance. Further research on variations in resources and treatment protocols among facilities, regions, and cultures will be useful in determining the feasibility of TOR rules for COVID-19 patients worldwide.

Community-level socioeconomic status and outcomes of patients with out-of-hospital cardiac arrest: A systematic review and meta analysis

BACKGROUND

The aim of this systematic review and meta-analysis was to investigate the associations of community-level socioeconomic status (SES) on outcomes of patients with out-of hospital cardiac arrest (OHCA).

METHODS

A systematic literature review was conducted using PubMed, EMBASE, and the Cochrane database according to guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We included literature that presented the outcomes based on community-level SES among patients with OHCA. SES indicators included economic indicators such as income, wealth, and occupation, as well as combined indicators, where any of these indicators were integrated. Outcomes were bystander cardiopulmonary resuscitation (CPR) and survival to discharge.

RESULTS

From 1394 titles, 10 cross-sectional observational studies fulfilled inclusion and exclusion criteria, representing 118,942 patients with OHCA. The odds ratios (ORs) of bystander CPR and survival to discharge for lower community-level SES patients were lower than those for higher community-level SES by economic SES indicators (bystander CPR OR 0.67; 95% CI 0.51-0.89, survival to discharge OR 0.60; 95% CI 0.35-1.02). Based on combined SES indicators the results showed similar patterns (bystander CPR OR 0.80; 95% CI 0.75-0.84, survival to discharge OR 0.76; 95% CI 0.63-0.92).

CONCLUSION

In this meta-analysis, community-level SES was significantly associated with bystander CPR and survival among patients with OHCA.

Effectiveness of bystander cardiopulmonary resuscitation in improving the survival and neurological recovery of patients with out-of-hospital cardiac arrest: A nationwide patient cohort study

INTRODUCTION

Few studies have focused on enhancing causality and yielding unbiased estimates on the effectiveness of bystander cardiopulmonary resuscitation (BCPR) on the outcomes of out-of-hospital cardiac arrest (OHCA) in a real-world setting. Therefore, this study evaluated the effect of BCPR on the outcomes of OHCA and its differences according to the characteristics of OHCA.

METHODS

This study enrolled all patients with OHCA of cardiac etiology treated by emergency medical services (EMS) in Korea from 2012 to 2015. The endpoints were survival and neurological recovery at discharge, and the main exposure was BCPR conducted by a layperson. The effect of BCPR was analyzed after adjusting for confounders, determined using a directed acyclic graph, by inverse probability of treatment weighting (IPTW) and model-based standardization (STR). Moreover, differences in subgroups and time trends were evaluated.

RESULTS

Among 10,505 eligible patients after excluding those with missing data on BCPR, 7,721 patients received BCPR, accounting for 74.3% of EMS-treated OHCA patients. BCPR increased the odds of survival and good neurological recovery at discharge by 1.67- (95% confidence interval (CI): 1.44-1.93) and 1.93- (95% CI: 1.56-2.39) fold, respectively, in the IPTW analysis. These findings were comparable to those obtained with STR. The odds ratios were 2.39 (95% CI: 1.91-2.94) and 2.70 (95% CI: 1.94-3.41), respectively, in the sensitivity analysis of the missing BCPR information considering confounders and the outcome variable. However, the effect of qualified BCPR was not evenly distributed, and it did not increase with time. BCPR was likely to be more effective in male patients aged <65 years, those who experienced an OHCA in a private place or non-capital region, and those with shockable rhythm at the scene.

CONCLUSION

Based on data from a nationwide registry, the estimated effect of BCPR on survival and neurological recovery was moderate and did not improve from 2012 to 2015.

Effect of citywide enhancement of the chain of survival on good neurologic outcomes after out-of-hospital cardiac arrest from 2008 to 2017

Improving outcomes after out-of-hospital cardiac arrests (OHCAs) requires an integrated approach by strengthening the chain of survival and emergency care systems. This study aimed to identify the change in outcomes over a decade and effect of citywide intervention on good neurologic outcomes after OHCAs in Daegu. This is a before- and after-intervention study to examine the association between the citywide intervention to improve the chain of survival and outcomes after OHCA. The primary outcome was a good neurologic outcome, defined as a cerebral performance category score of 1 or 2. After dividing into 3 phases according to the citywide intervention, the trends in outcomes after OHCA by primary electrocardiogram rhythm were assessed. Logistic regression analysis was used to analyze the association between the phases and outcomes. Overall, 6203 patients with OHCA were eligible. For 10 years (2008–2017), the rate of survival to discharge and the good neurologic outcomes increased from 2.6% to 8.7% and from 1.5% to 6.6%, respectively. Especially for patients with an initial shockable rhythm, these changes in outcomes were more pronounced (survival to discharge: 23.3% in 2008 to 55.0% in 2017, good neurologic outcomes: 13.3% to 46.0%). Compared with phase 1, the adjusted odds ratio (AOR) and 95% confidence intervals (CI) for good neurologic outcomes was 1.20 (95% CI: 0.78–1.85) for phase 2 and 1.64 (1.09–2.46) for phase 3. For patients with an initial shockable rhythm, the AOR for good neurologic outcomes was 3.76 (1.88–7.52) for phase 2 and 5.51 (2.77–10.98) for phase 3. Citywide improvement was observed in the good neurologic outcomes after OHCAs of medical origin, and the citywide intervention was significantly associated with better outcomes, particularly in those with initial shockable rhythm.

The effect of system performance improvement on patients with cardiac arrest: A systematic review

AIM

The aim of our review was to understand the effect of interventions to improve system-level performance on the clinical outcomes of patients with cardiac arrest.

METHODS

We searched PubMed, Ovid EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases to identify randomised controlled trials and non-randomised studies published before July 21, 2020 reporting systems interventions to improve outcomes. Characteristics, study design, evaluation methods and outcomes of included studies were extracted. (PROSPERO registration CRD42020161882).

RESULTS

One cluster randomised trial and 26 non-randomised studies were included. There were 18 studies focusing on interventions for patients with out-of-hospital cardiac arrest and 9 studies for patients with in-hospital cardiac arrest. Interventions included implementation of a bundle of care strategy, evaluation of cardiopulmonary resuscitation (CPR) quality with feedback/debriefing, data surveillance, and CPR training programs. Although improved survival with favorable neurologic outcome at discharge after the implementation of specific interventions was found in 13 studies, improved survival to hospital discharge in 14 studies and improved survival to admission in 3 studies, there were still 7 studies showing no significant improvement of clinical outcomes after interventions.

CONCLUSION

Although only moderate to very low certainty of evidence exists to support the effect of system-level performance improvement on the clinical outcomes of patients, we recommend that organisations or communities evaluate their performance and target key areas with the goal to improve performance because of no known risks and the potential for a large beneficial effect.

Education, Implementation, and Teams: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

For this 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations, the Education, Implementation, and Teams Task Force applied the population, intervention, comparator, outcome, study design, time frame format and performed 15 systematic reviews, applying the Grading of Recommendations, Assessment, Development, and Evaluation guidance. Furthermore, 4 scoping reviews and 7 evidence updates assessed any new evidence to determine if a change in any existing treatment recommendation was required. The topics covered included training for the treatment of opioid overdose; basic life support, including automated external defibrillator training; measuring implementation and performance in communities, and cardiac arrest centers; advanced life support training, including team and leadership training and rapid response teams; measuring cardiopulmonary resuscitation performance, feedback devices, and debriefing; and the use of social media to improve cardiopulmonary resuscitation application.

Education, Implementation, and Teams: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

For this 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations, the Education, Implementation, and Teams Task Force applied the population, intervention, comparator, outcome, study design, time frame format and performed 15 systematic reviews, applying the Grading of Recommendations, Assessment, Development, and Evaluation guidance. Furthermore, 4 scoping reviews and 7 evidence updates assessed any new evidence to determine if a change in any existing treatment recommendation was required. The topics covered included training for the treatment of opioid overdose; basic life support, including automated external defibrillator training; measuring implementation and performance in communities, and cardiac arrest centers; advanced life support training, including team and leadership training and rapid response teams; measuring cardiopulmonary resuscitation performance, feedback devices, and debriefing; and the use of social media to improve cardiopulmonary resuscitation application.

Part 7: Systems of Care: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

Survival after cardiac arrest requires an integrated system of people, training, equipment, and organizations working together to achieve a common goal. Part 7 of the 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care focuses on systems of care, with an emphasis on elements that are relevant to a broad range of resuscitation situations. Previous systems of care guidelines have identified a Chain of Survival, beginning with prevention and early identification of cardiac arrest and proceeding through resuscitation to post-cardiac arrest care. This concept is reinforced by the addition of recovery as an important stage in cardiac arrest survival. Debriefing and other quality improvement strategies were previously mentioned and are now emphasized. Specific to out-of-hospital cardiac arrest, this Part contains recommendations about community initiatives to promote cardiac arrest recognition, cardiopulmonary resuscitation, public access defibrillation, mobile phone technologies to summon first responders, and an enhanced role for emergency telecommunicators. Germane to in-hospital cardiac arrest are recommendations about the recognition and stabilization of hospital patients at risk for developing cardiac arrest. This Part also includes recommendations about clinical debriefing, transport to specialized cardiac arrest centers, organ donation, and performance measurement across the continuum of resuscitation situations.

Effects of positive dispatcher encouragement on the maintenance of bystander cardiopulmonary resuscitation quality

BACKGROUND

Implementation of dispatcher-assisted cardiopulmonary resuscitation (DACPR) has increased the likelihood of bystander CPR upon cardiac arrest. However, the quality of CPR has been found to be very low. In this study, we aimed to compare CPR quality between the current DACPR practices and the interventional instruction of adding verbal encouragement from the dispatcher.

METHODS

In this randomized controlled trial, we recruited adult (age ≥18) laypersons who were non-health care providers and had never received any previous verified CPR training. They were randomly selected to perform DACPR using metronome sounds (mDACPR) as per the standard protocol, or DACPR with metronome sounds along with human encouragement (mheDACPR). The ratio of accurate compression rate, depth, and complete release for each CPR phase was examined.

RESULTS

Sixty nine records (34, mDACPR; 35, mheDACPR) were taken. The median proportion of accurate chest compression rate was initially 29.5% with mDACPR, and significantly increased to 71% after 2 minutes of CPR administration (P = .046). However, the median ratio of accurate chest compression depth was 61.5% in the first phase, and significantly decreased to 0% in the last phase (P < .001). In contrast, for the mheDACPR group, a high accurate compression rate was maintained throughout the 2 minutes of CPR administration (91%, 100%, 100%, 100%).

CONCLUSION

To maintain the quality of CPR administered by bystanders, continuous feedback and repeated human encouragement should be provided during DACPR. Active dispatcher intervention reduces the time required to reach an appropriate CPR rate and allows for the maintenance of accurate compression rates.

Preparedness of personal protective equipment and implementation of new CPR strategies for patients with out-of-hospital cardiac arrest in the COVID-19 era

BACKGROUND

In February and March 2020, healthcare providers and citizens in Daegu, South Korea, experienced the onslaught of a large-scale community epidemic of COVID-19. This had a profound impact on patients who experienced out-of-hospital cardiac arrest (OHCA).

METHODS

We conducted a retrospective observational study of 171 OHCA patients based on the multicenter WinCOVID registry. Demographic and clinical characteristics, overall survival, COVID-19 related data, as well as personal protective equipment (PPE) and resuscitation techniques used during the COVID-19 outbreak were evaluated and compared with outcomes from a 2018 historical cohort (n ​= ​158).

RESULTS

Among the interventions, high-level PPE was introduced and standard cardiopulmonary resuscitation was changed to chest compressions using mechanical devices. All OHCA patients were treated as confirmed or suspicious for COVID-19 regardless of symptoms. Furthermore, complete or partial closures of emergency centers and the number of medical personnel requiring self-isolation decreased in response to the introduction of isolated resuscitation units. However, the adjusted odds ratio and 95% confidence intervals for survival discharge and favorable neurologic outcome were 0.51 (0.25-0.97) and 0.45 (0.21-1.07) compared with those in the 2018 historical cohort.

CONCLUSIONS

Responses to the COVID-19 pandemic included changes to current PPE strategies and introduction of isolated resuscitation units; the latter intervention reduced the number of unexpected closures and quarantines of emergency resources early on during the COVID-19 outbreak. Given the possibility of future outbreaks, we need to have revised resuscitation strategies and the capacity to commandeer emergency resources for OHCA patients.

Effects of Prehospital Factors on Survival of Out-Of-Hospital Cardiac Arrest Patients: Age-Dependent Patterns

Many prehospital factors that are known to influence survival rates after out-of-hospital cardiac arrest (OHCA) have been rarely studied as to how their influence varies depending on the age. In this study, we tried to find out what prehospital factors affect the survival rate after OHCA by age groups and how large the effect size of those factors is in each age group. We used the South Korean OHCA registry, which includes information on various prehospital factors relating OHCA and final survival status. The association between prehospital factors and survival was explored through logistic regression analyses for each age group. The effects of prehospital factors vary depending on the patient’s age. Being witnessed was relatively more influential in younger patients and the presence of first responders became more important as patients became older. While bystander cardiopulmonary resuscitation (CPR) did not appear to significantly affect survival in younger people, use of an automated external defibrillator (AED) showed the largest effect size on the survival in all age groups. Since the pathophysiology and etiologies of OHCA vary according to age, more detailed information on life support by age is needed for the development and application of more specialized protocols for each age.

Vasospasm-related Sudden Cardiac Death Has Outcomes Comparable with Coronary Stenosis in Out-of-Hospital Cardiac Arrest

BACKGROUND

Characteristics of coronary vasospasm-related sudden cardiac death are not well understood. We aimed to compare the characteristics and clinical outcomes between coronary vasospasm and stenosis, in out-of-hospital cardiac arrest (OHCA) survivors, who underwent coronary angiogram (CAG).

METHODS

We conducted a multicenter retrospective observational registry-based study at 8 Korean tertiary care centers. Data of OHCA survivors undergoing CAG between 2010 and 2015 were extracted. Patients were divided into vasospasm and stenosis (stenosis > 50%) groups based on CAG findings. The primary and the secondary outcomes were survival and a good neurologic outcome at 30 days after OHCA. Patients in the vasospasm and stenosis groups were propensity score matched.

RESULTS

Of the 413 included patients, vasospasm and stenosis groups comprised 87 and 326 patients, respectively. There were 279 (66.7%) survivors and 206 (49.3%) patients with good neurologic outcomes. The vasospasm group had better clinical characteristics for outcome (younger age, less diabetes and hypertension, more prehospital restoration of spontaneous circulation, higher Glasgow Coma Scale, less ST segment elevation, and less requirement of circulatory support). The vasospasm group had better survival (75/87 vs. 204/326, P < 0.001) and good neurologic outcomes (62/87 vs. 144/326, P < 0.001). However, vasospasm was not independently associated with survival (odds ratio [OR], 0.980; 95% confidence interval [CI], 0.400-2.406) or neurologic outcomes (OR, 0.870; 95% CI, 0.359-2.108) after adjustment and vasospasm was not associated with survival and neurologic outcome in propensity score-matched cohorts.

CONCLUSION

Our analysis of propensity score-matched cohorts finds that vasospasm OHCA survivors have survival and neurologic outcomes comparable with those of stenotic OHCA survivors.

Place-provider-matrix of bystander cardiopulmonary resuscitation and outcomes of out-of-hospital cardiac arrest: A nationwide observational cross-sectional analysis

AIMS

This study aims to test the association between the place-provider-matrix (PPM) of bystander cardiopulmonary resuscitation (CPR) and outcomes of out-of-hospital cardiac arrest (OHCA).

METHODS

Adult patients with OHCA with a cardiac etiology from 2012 to 2017 in Korea were analyzed, excluding patients who had unknown information on place, type of bystander, or outcome. The PPM was categorized into six groups by two types of places (public versus home) and three types of providers (trained responder (TR), family bystander, and layperson bystander). Outcomes were survival to discharge and good cerebral performance category (CPC) of 1 or 2. Multivariable logistic regression analysis was performed to test the association between PPM group and outcomes with adjustment for potential confounders to calculate adjusted odds ratios (AORs) and 95% confidence intervals (CIs) (reference = Public-TR).

RESULTS

A total of 73,057 patients were analyzed and were categorized into Public-TR (0.6%), Home-TR (0.3%), Public-Family (1.8%), Home-Family (79.8%), Public-Layperson (9.9%), and Home-Layperson (7.6%) groups. Compared with the Public-TR group, the AORs (95% CIs) for survival to discharge were 0.61 (0.35-1.05) in the Home-TR group, 0.85 (0.62-1.17) in the Public-Family group, 0.38 (0.29-0.50) in the Home-Family group, 1.12 (0.85-1.49) in the Public-Layperson group, and 0.42 (0.31-0.57) in the Home-Layperson group. The AORs (95% CIs) for good CPC were 0.58 (0.27-1.25) in the Home-TR group, 0.88 (0.61-1.27) in the Public-Family group, 0.38 (0.28-0.52) in the Home-Family group, 1.20 (0.87-1.65) in the Public-Layperson group, and 0.42 (0.30-0.59) in the Home-Layperson group.

CONCLUSION

The OHCA outcomes of the Home-Family and Home-Layperson groups were worse than those of the Public-TR group. This finding suggests that OHCA occurring in private places with family or layperson bystanders requires a new strategy, such as dispatching trained responders to the scene to improve CPR outcomes.

Utstein recommendation for emergency stroke care

Background

Recent advances in treatment for stroke give new possibilities for optimizing outcomes. To deliver these prehospital care needs to become more efficient.

Aim

To develop a framework to support improved delivery of prehospital care. The recommendations are aimed at clinicians involved in prehospital and emergency health systems who will often not be stroke specialists but need clear guidance as to how to develop and deliver safe and effective care for acute stroke patients.

Methods

Building on the successful implementation program from the Global Resuscitation Alliance and the Resuscitation Academy, the Utstein methodology was used to define a generic chain of survival for Emergency Stroke Care by assembling international expertise in Stroke and Emergency Medical Services (EMS). Ten programs were identified for Acute Stroke Care to improve survival and outcomes, with recommendations for implementation of best practice.

Conclusions

Efficient prehospital systems for acute stroke will be improved through public awareness, optimized prehospital triage and timely diagnostics, and quick and equitable access to acute treatments. Documentation, use of metrics and transparency will help to build a culture of excellence and accountability.

Factors Associated with High-Quality Cardiopulmonary Resuscitation Performed by Bystander

Bystander cardiopulmonary dresuscitation (CPR) improves the survival and neurological outcomes of sudden cardiac arrest patients. The rate of bystander CPR is increasing; however, its performance quality has not been evaluated in detail. In this study, emergency medical technicians (EMTs) in the field evaluated bystander CPR quality, and we aimed to investigate the association between bystander information and CPR quality. This retrospective cohort study was based on data included in the Smart Advanced Life Support (SALS) registry between January 2016 and December 2017. We included patients older than 18 years who experienced an out-of-hospital cardiac arrest (OHCA) due to medical causes. Bystander CPR quality was judged to be "high" when the hand positions were appropriate and when compression rates of at least 100/min and compression depths of at least 5 cm were achieved. Among 6,769 eligible patients, 3,799 (58.7%) received bystander CPR, and 6% of bystanders performed high-quality CPR. After adjustment, the occurrence of cardiac arrest at home (adjusted odds ratio (aOR), 95% confidence interval (CI); 0.42, 0.27-0.64), witnessed cardiac arrest (1.45, 1.03-2.06), and younger bystander age all showed associations with one another. High-quality CPR led to a 4.29-fold increase in the chance of neurological recovery. In particular, high-quality CPR in patients aged 60 years showed a significant association compared with other age groups (7.61, 1.41-41.04). The main factor affecting CPR quality in this study was the age of the bystander, and older bystanders found it more difficult to maintain CPR quality. To improve the quality of bystander CPR, training among older bystanders should be the focus.

Association between health insurance status and transfer of patients with return of spontaneous circulation after out-of-hospital cardiac arrest

AIM

To explore the factors related to the probability of inter-hospital transfer to a heart attack centre in patients with return of spontaneous circulation after out-of-hospital cardiac arrest (OHCA) in the Republic of Korea.

METHODS

This cross-sectional observational study used data from a Korean national emergency medical service OHCA database for cases between 2015 and 2017. Adult OHCA patients with a presumed cardiac origin who initially presented at a non-heart-attack centre were included in the analysis. The main exposure variable was health insurance type (national health insurance versus medical aid), which was used as a proxy measure of individual socioeconomic status. The primary outcome was emergency department disposition (transfer to a heart attack centre versus no transfer). A multivariate logistic analysis using propensity score matching was conducted. We also analysed the associations between patient transfer and neurologic recovery as well as survival to discharge.

RESULTS

Of 7804 eligible OHCA patients, 1804 23.0%) were transferred to a heart attack centre. Patients on medical aid were less likely to be transferred (adjusted odds ratio [OR], 0.75; 95% confidence interval [CI], 0.59-0.95 in a matched cohort) compared with patients with national health insurance. Transfer to a heart attack centre was significantly associated with a lower risk of death (adjusted OR, 0.38; 95% CI, 0.33-0.45) and better neurologic recovery (adjusted OR, 0.46; 95% CI, 0.38-0.56).

CONCLUSION

Socioeconomic status appears likely to influence the probability of transfer to a heart attack centre after resuscitation.

Key components of a community response to out-of-hospital cardiac arrest

Out-of-hospital cardiac arrest (OHCA) remains a leading cause of death worldwide, with substantial geographical, ethnic and socioeconomic disparities in outcome. Successful resuscitation efforts depend on the 'chain of survival', which includes immediate recognition of cardiac arrest and activation of the emergency response system, early bystander cardiopulmonary resuscitation (CPR) with an emphasis on chest compressions, rapid defibrillation, basic and advanced emergency medical services and integrated post-cardiac arrest care. Well-orchestrated telecommunicator CPR programmes can improve rates of bystander CPR - a critical link in the chain of survival. High-performance CPR by emergency medical service providers includes minimizing interruptions in chest compressions and ensuring adequate depth of compressions. Developing local, regional and statewide systems with dedicated high-performing cardiac resuscitation centres for post-resuscitation care can substantially improve survival after OHCA. Innovative digital tools for recognizing cardiac arrest where and when it occurs, notifying potential citizen rescuers and providing automated external defibrillators at the scene hold the promise of improving survival after OHCA. Improved implementation of the chain of survival can save thousands of lives each year.

Comparison of the effects of audio-instructed and video-instructed dispatcher-assisted cardiopulmonary resuscitation on resuscitation outcomes after out-of-hospital cardiac arrest

BACKGROUND

This study compared the real-world effects of audio-instructed dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) and video-instructed DA-CPR on resuscitation outcomes after out-of-hospital cardiac arrest (OHCA).

METHODS

A retrospective cohort study was conducted among adult OHCA patients in whom resuscitation was attempted in 2017 in Seoul, Korea. The dispatch center of Seoul introduced video-instructed DA-CPR in 2017, whereas audio-instructed DA-CPR was first implemented in 2010. When more than two bystanders were at the scene and could handle a video-call, the dispatcher call back a video-call and provided CPR instructions. In other situations, standard audio-instructed DA-CPR was provided. The primary outcome was survival to discharge. The secondary outcome was good neurological outcome at hospital discharge. The tertiary outcome was early instruction time interval (ITI, time from call to the initiation of CPR instruction ≤90 s). The study outcomes of audio-instructed DA-CPR (audio group) and video-instructed DA-CPR (video group) were compared. The propensity score matching (PSM) method was used to increase the comparability of the two groups and the logistic regression was performed for the PSM cohort.

RESULTS

A total of 1720 eligible OHCA patients (1489 and 231 in the audio and video groups, respectively) were evaluated. The median ITI was 136 s in the audio group and 122 s in the video group (p = 0.12). The survival to discharge rates were 8.9% in the audio group and 14.3% in the video groups (p < 0.01). Good neurological outcome occurred in 5.8% and 10.4% in the audio and video groups, respectively (p < 0.01). Compared to the audio group, the AORs (95% CIs) for survival to discharge, good neurological outcome and early ITI of the video group were 1.20 (0.74-1.94), 1.28 (0.73-2.26) and 1.00 (0.70-1.43), respectively. The PSM population showed similar results as those of the original cohort.

CONCLUSION

Compared to audio-instructed DA-CPR, video-instructed DA-CPR was not associated with survival improvement in this observational study conducted in one metropolitan city. Randomized controlled trials are needed to compare the effects of video- and audio-instructed DA-CPR.

Effect of the Floor Level on the Probability of a Neurologically Favorable Discharge after Cardiac Arrest according to the Event Location

As the number of people living in high-rise buildings increases, so does the incidence of cardiac arrest in these locations. Changes in cardiac arrest location affect the recognition of patients and emergency medical service (EMS) activation and response. This study aimed to compare the EMS response times and probability of a neurologically favorable discharge among patients who suffered an out-of-hospital cardiac arrest (OHCA) event while on a high or low floor at home or in a public place. This retrospective analysis was based on Smart Advanced Life Support registry data from January 2016 to December 2017. We included patients older than 18 years who suffered an OHCA due to medical causes. A high floor was defined as ≥3^rd floor above ground. We compared the probability of a neurologically favorable discharge according to floor level and location (home vs. public place) of the OHCA event. Of the 6,335 included OHCA cases, 4,154 (65.6%) events occurred in homes. Rapid call-to-scene times were reported for high-floor events in both homes and public places. A longer call-to-patient time was observed for home events. The probability of a neurologically favorable discharge after a high-floor OHCA was significantly lower than that after a low-floor OHCA if the event occurred in a public place (adjusted odds ratio (aOR), 0.58; 95% confidence intervals (CI), 0.37-0.89) but was higher if the event occurred at home (aOR, 1.40; 95% CI, 0.96-2.03). Both the EMS response times to OHCA events in high-rise buildings and the probability of a neurologically favorable discharge differed between homes and public places. The results suggest that the prognosis of an OHCA patient is more likely to be affected by the building structure and use rather than the floor height.

Prediction of good neurological recovery after out-of-hospital cardiac arrest: A machine learning analysis

BACKGROUND

This study aimed to train, validate and compare predictive models that use machine learning analysis for good neurological recovery in OHCA patients.

METHODS

Adult OHCA patients who had a presumed cardiac etiology and a sustained return of spontaneous circulation between 2013 and 2016 were analyzed; 80% of the individuals were analyzed for training and 20% were analyzed for validation. We developed using six machine learning algorithms: logistic regression (LR), extreme gradient boosting (XGB), support vector machine, random forest, elastic net (EN), and neural network. Variables that could be obtained within 24 hours of the emergency department visit were used. The area under the receiver operation curve (AUROC) was calculated to assess the discrimination. Calibration was assessed by the Hosmer-Lemeshow test. Reclassification was assessed by using the continuous net reclassification index (NRI).

RESULTS

A total of 19,860 OHCA patients were included in the analysis. Of the 15,888 patients in the training group, 2228 (14.0%) had a good neurological recovery; of the 3972 patients in the validation group, 577 (14.5%) had a good neurological recovery. The LR, XGB, and EN models showed the highest discrimination powers (AUROC (95% CI)) of 0.949 (0.941-0.957) for all), and all three models were well calibrated (Hosmer-Lemeshow test: p >0.05). The XGB model reclassified patients according to their true risk better than the LR model (NRI: 0.110), but the EN model reclassified patients worse than the LR model (NRI: -1.239).

CONCLUSION

The best performing machine learning algorithm was the XGB and LR algorithm.

Effect of Implementation of Cardiopulmonary Resuscitation-Targeted Multi-Tier Response System on Outcomes After Out-of-Hospital Cardiac Arrest: A Before-and-After Population-Based Study

Objective: A multi-tiered response (MTR) system has been controversial in terms of cost-effectiveness and outcome improvement. It remains uncertain whether a cardiopulmonary resuscitation (CPR)-targeted tiered response system is associated with better outcomes after out-of-hospital cardiac arrest (OHCA). This study aimed to investigate the effect of an MTR on OHCA outcomes. Methods: A natural experimental study was conducted for resuscitation-attempted adult OHCAs. The MTR system was implemented in Korea by the National Fire Agency in 2015 across the country where the single-tiered ambulance response system existed. The MTR program had the following 3 components: 1) detection of OHCA by dispatcher, 2) dispatch of ambulance or fire engine in addition to routine dispatch of ambulance, and 3) performance of team CPR. The study period of 2015-2016 was divided by 6 months (phases I [reference], II, III, and IV). The endpoints were prehospital defibrillation, prehospital return of spontaneous circulation (PROSC), survival to discharge and good neurological recovery. A multivariable logistic regression analysis was performed to evaluate the effect of the intervention, and adjusted odds ratios (AORs) with 95% confidence intervals (CIs) were calculated, adjusting for potential confounders. Results: A total of 32,663 eligible OHCA cases were evaluated during the study period. As the intervention program spread, the MTR with ambulance increased (from 7.0% in phase I to 53.7% in phase IV, p for trend < 0.01). During the study period, prehospital defibrillation increased from 23.6% in phase I to 26.9% in phase IV and the study outcome was improved from 7.4 to 12.6% for PROSC, from 6.7 to 9.1% for survival to discharge, and from 4.5 to 5.8% for good neurological outcome (p for trend < 0.01 for all). Compared with phase I, the AORs (95% CI) of phase IV were 1.16 (1.08-1.25) for prehospital defibrillation, 1.82 (1.63-2.04) for PROSC, 1.37 (1.21-1.56) for survival to discharge, and 1.23 (1.06-1.43) for good neurological outcome. Conclusion: The nationwide implementation of a multi-tiered response system for OHCA was associated with increased prehospital defibrillation and improved outcomes of OHCA patients.

High Incidence and Mortality of Out-of-Hospital Cardiac Arrest on Traditional Holiday in South Korea

BACKGROUND AND OBJECTIVES

This study aimed to confirm the effects of traditional holidays on the incidence and outcomes of out-of-hospital cardiac arrest (OHCA) in South Korea.

METHODS

We studied 95,066 OHCAs of cardiac cause from a nationwide, prospective study from the Korea OHCA Registry from January 2012 to December 2016. We compared the incidence of OHCA, in-hospital mortality, and neurologic outcomes between traditional holidays, Seollal (Lunar New Year's Day) and Chuseok (Korean Thanksgiving Day), and other day types (weekday, weekend, and public holiday).

RESULTS

OHCA occurred more frequently on traditional holidays than on the other days. The median OHCA incidence were 51.0 (interquartile range [IQR], 44.0-58.0), 53.0 (IQR, 46.0-60.5), 52.5 (IQR, 45.3-59.8), and 60.0 (IQR, 52.0-69.0) cases/day on weekday, weekend, public holiday, and traditional holiday, respectively (p<0.001). The OHCA occurred more often at home rather than in public place, lesser bystander cardiopulmonary resuscitation (CPR) was performed, and the rate of cessation of CPR within 20 minutes without recovery of spontaneous circulation was higher on traditional holiday. After multivariable adjustment, traditional holiday was associated with higher in-hospital mortality (adjusted hazard ratio [HR], 1.339; 95% confidence interval [CI], 1.058-1.704; p=0.016) but better neurologic outcomes (adjusted HR, 0.503; 95% CI, 0.281-0.894; p=0.020) than weekdays.

CONCLUSIONS

The incidence of OHCAs was associated with day types in a year. It occurred more frequently on traditional holidays than on other day types. It was associated with higher in-hospital mortality and favorable neurologic outcomes than weekday.