Aetiology of resuscitated out-of-hospital cardiac arrest treated at hospital

Sex and 30-day survival following out-of-hospital cardiac arrest in Scotland 2011-2020

BACKGROUND

Differences in 30-day survival between males and females following out-of-hospital cardiac arrest (OHCA) are well documented. Biological sex does not appear to be responsible for this survival gap independently of potential mediating factors. We investigated the role of potential mediating factors in the association between sex and 30-day survival after OHCA in Scotland.

METHODS

A retrospective cohort study of adult non-emergency medical services (EMS)-witnessed OHCA cases was conducted. We included incidents from the whole of Scotland where resuscitation was attempted by the Scottish Ambulance Service (SAS) between April 1, 2011 and March 1, 2020. Logistic regression was used to assess the contribution of age, socioeconomic status, urban-rural location of the incident, initial cardiac rhythm, bystander cardiopulmonary resuscitation (CPR) and location of the arrest (home or away from home).

RESULTS

The cohort consisted of 20,585 OHCA cases (13,130 males and 7,455 females). Median (IQR) age was 69 years (22) for males versus 72 years (23) for females. A higher proportion of males presented with initial shockable rhythm (29.4% versus 12.4%) and received bystander CPR (56.7% versus 53.2%) compared with females. A higher proportion of females experienced OHCA at home (78.8% versus 66.8%). Thirty-day survival after OHCA was higher for males compared with females (8.2% versus 6.2%). Males had higher age-adjusted odds for 30-day survival after OHCA than females (OR, 1.26; (95% CI), 1.12-1.41). Mediation analyses suggested a role for initial cardiac rhythm and location of the arrest (home or away from home).

CONCLUSION

Males had higher age-adjusted 30-day survival after OHCA than females. However, after adjusting for confounding/mediating variables, sex was not associated with 30-day survival after OHCA. Our findings suggest that initial cardiac rhythm and location of the arrest are potential mediators of higher 30-day OHCA survival in males than females. Improving proportions of females who present with initial shockable rhythm may reduce sex differences in survival after OHCA.

Resuscitation of out-of-hospital cardiac arrest victims in Austria's largest helicopter emergency medical service: A retrospective cohort study

Background

Helicopter emergency medical services (HEMS) play a fundamental role in prehospital care. However, the impact of HEMS on survival of patients with out-of-hospital cardiac arrest (OHCA) is widely unknown. Therefore, the purpose of this study was to assess demographics, treatment, and outcome of patients with OHCA attended by physician-staffed helicopters.

Methods

Retrospective cohort study enrolling OHCA patients treated by HEMS during a ten-year period (2010-2019) in Austria. Patients were identified using electronic mission records of 13 HEMS bases run by the Austrian Automobile, Motorcycle and Touring Club (OEAMTC), and subsequently matched with the national register of deaths to determine 30-day and one-year survival rates. Results are reported according to the 2015 Utstein Style. Multivariable logistic regression analysis was used to identify factors associated with patient outcome.

Results

In total, 9344 presumed OHCA missions were identified. Cardiopulmonary resuscitation was attempted or continued by HEMS in 3889 cases. Approximately 32.2% of patients achieved return of spontaneous circulation (ROSC) and 22.5% sustained ROSC until arrival at the emergency department. Thirty-day and one-year survival rates were 14.0% and 12.4% respectively. HEMS response time, on-scene time, age, pathogenesis, arrest location, witness-status, first monitored rhythm, bystander automated external defibrillator (AED) use, airway type and administration of adrenaline were independent predictors of 30-day survival.

Conclusions

This study provides an extensive insight into the management of OHCA in an almost nationwide HEMS sample. Thirty-day and one-year survival rates are high, indicating high-quality care and systematic selection of patients with favorable prognosis.

Cardiac Arrest and Cardiopulmonary Resuscitation Outcome Reports: 2024 Update of the Utstein Out-of-Hospital Cardiac Arrest Registry Template

The Utstein Out-of-Hospital Cardiac Arrest Resuscitation Registry Template, introduced in 1991 and updated in 2004 and 2015, standardizes data collection to enable research, evaluation, and comparisons of systems of care. The impetus for the current update stemmed from significant advances in the field and insights from registry development and regional comparisons. This 2024 update involved representatives of the International Liaison Committee on Resuscitation and used a modified Delphi process. Every 2015 Utstein data element was reviewed for relevance, priority (core or supplemental), and improvement. New variables were proposed and refined. All changes were voted on for inclusion. The 2015 domains-system, dispatch, patient, process, and outcomes-were retained. Further clarity is provided for the definitions of out-of-hospital cardiac arrest attended resuscitation and attempted resuscitation. Changes reflect advancements in dispatch, early response systems, and resuscitation care, as well as the importance of prehospital outcomes. Time intervals such as emergency medical service response time now emphasize precise reporting of the times used. New flowcharts aid the reporting of system effectiveness for patients with an attempted resuscitation and system efficacy for the Utstein comparator group. Recognizing the varying capacities of emergency systems globally, the writing group provided a minimal dataset for settings with developing emergency medical systems. Supplementary variables are considered useful for research purposes. These revisions aim to elevate data collection and reporting transparency by registries and researchers and to advance international comparisons and collaborations. The overarching objective remains the improvement of outcomes for patients with out-of-hospital cardiac arrest.

Cardiac arrest and cardiopulmonary resuscitation outcome reports: 2024 update of the Utstein Out-of-Hospital Cardiac Arrest Registry template

The Utstein Out-of-Hospital Cardiac Arrest Resuscitation Registry Template, introduced in 1991 and updated in 2004 and 2015, standardizes data collection to enable research, evaluation, and comparisons of systems of care. The impetus for the current update stemmed from significant advances in the field and insights from registry development and regional comparisons. This 2024 update involved representatives of the International Liaison Committee on Resuscitation and used a modified Delphi process. Every 2015 Utstein data element was reviewed for relevance, priority (core or supplemental), and improvement. New variables were proposed and refined. All changes were voted on for inclusion. The 2015 domains-system, dispatch, patient, process, and outcomes-were retained. Further clarity is provided for the definitions of out-of-hospital cardiac arrest attended resuscitation and attempted resuscitation. Changes reflect advancements in dispatch, early response systems, and resuscitation care, as well as the importance of prehospital outcomes. Time intervals such as emergency medical service response time now emphasize precise reporting of the times used. New flowcharts aid the reporting of system effectiveness for patients with an attempted resuscitation and system efficacy for the Utstein comparator group. Recognizing the varying capacities of emergency systems globally, the writing group provided a minimal dataset for settings with developing emergency medical systems. Supplementary variables are considered useful for research purposes. These revisions aim to elevate data collection and reporting transparency by registries and researchers and to advance international comparisons and collaborations. The overarching objective remains the improvement of outcomes for patients with out-of-hospital cardiac arrest.

Etiology-Based Prognosis of Extracorporeal CPR Recipients After Out-of-Hospital Cardiac Arrest: A Retrospective Multicenter Cohort Study

BACKGROUND

A better understanding of the relative contributions of various factors to patient outcomes is essential for optimal patient selection for extracorporeal CPR (ECPR) therapy for patients with out-of-hospital cardiac arrest (OHCA). However, evidence on the prognostic comparison based on the etiologies of cardiac arrest is limited.

RESEARCH QUESTION

What is the etiology-based prognosis of patients undergoing ECPR for OHCA?

STUDY DESIGN AND METHODS

This retrospective multicenter registry study involved 36 institutions in Japan and included all adult patients with OHCA who underwent ECPR between January 2013 and December 2018. The primary etiology for OHCA was determined retrospectively from all hospital-based data at each institution. We performed a multivariable logistic regression model to determine the association between etiology of cardiac arrest and two outcomes: favorable neurologic outcome and survival at hospital discharge.

RESULTS

We identified 1,781 eligible patients, of whom 1,405 (78.9%) had cardiac arrest because of cardiac causes. Multivariable logistic regression analysis for favorable neurologic outcome showed that accidental hypothermia (adjusted OR, 5.12; 95% CI, 2.98-8.80; P < .001) was associated with a significantly higher rate of favorable neurologic outcome than cardiac causes. Multivariable logistic regression analysis for survival showed that accidental hypothermia (adjusted OR, 5.19; 95% CI, 3.15-8.56; P < .001) had significantly higher rates of survival than cardiac causes. Acute aortic dissection/aneurysm (adjusted OR, 0.07; 95% CI, 0.02-0.28; P < .001) and primary cerebral disorders (adjusted OR, 0.12; 95% CI, 0.03-0.50; P = .004) had significantly lower rates of survival than cardiac causes.

INTERPRETATION

In this retrospective multicenter cohort study, although most patients with OHCA underwent ECPR for cardiac causes, accidental hypothermia was associated with favorable neurologic outcome and survival; in contrast, acute aortic dissection/aneurysm and primary cerebral disorders were associated with nonsurvival compared with cardiac causes.

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Temporal trends in out-of-hospital cardiac arrest with an initial non-shockable rhythm in Singapore

Aim

Out-of-hospital cardiac arrest (OHCA) with an initial non-shockable rhythm is the predominant form of OHCA in adults. We evaluated its 10-year trends in epidemiology and management in Singapore.

Methods

Using the national OHCA registry we studied the trends of 20,844 Emergency Medical Services-attended adult OHCA from April 2010 to December 2019. Survival to hospital discharge was the primary outcome. Trends and outcomes were analyzed using linear and logistic regression, respectively.

Results

Incidence rates of adult OHCAs increased during the study period, driven by non-shockable OHCA. Compared to shockable OHCA, non-shockable OHCAs were significantly older, had more co-morbidities, unwitnessed and residential arrests, longer no-flow time, and received less bystander cardiopulmonary resuscitation (CPR) and in-hospital interventions (p < 0.001). Amongst non-shockable OHCA, age, co-morbidities, residential arrests, no-flow time, time to patient, bystander CPR and epinephrine administration increased during the study period, while presumed cardiac etiology decreased (p < 0.05). Unlike shockable OHCA, survival for non-shockable OHCA did not improve (p < 0.001 for trend difference). The likelihood of survival for non-shockable OHCA significantly increased with witnessed arrest (adjusted odds ratio (aOR) 2.02) and bystander CPR (aOR 3.25), but decreased with presumed cardiac etiology (aOR 0.65), epinephrine administration (aOR 0.66), time to patient (aOR 0.93) and age (aOR 0.98). Significant two-way interactions were observed for no-flow time and residential arrest with bystander CPR (aOR 0.96 and 0.40 respectively).

Conclusion

The incidence of non-shockable OHCA increased between 2010 and 2019. Despite increased interventions, survival did not improve for non-shockable OHCA, in contrast to the improved survival for shockable OHCA.

Development and validation of a novel score to predict brain death after out-of-hospital cardiac arrest

BACKGROUND AND OBJECTIVES

Brain death (BD) occurs in 9-24% of successfully resuscitated out-of-hospital cardiac arrests (OHCA). To predict BD after OHCA, we developed a novel brain death risk (BDR) score.

METHODS

We identified independent predictors of BD after OHCA in a retrospective, single academic center cohort between 2011 and 2021. The BDR score ranges from 0 to 7 points and includes: non-shockable rhythm (1 point), drug overdose as etiology of arrest (1 point), evidence of grey-white differentiation loss or sulcal effacement on head computed tomography (CT) radiology report within 24 hours of arrest (2 points), Full-Outline-Of-UnResponsiveness (FOUR) score of 0 (2 points), FOUR score 1-5 (1 point), and age <45 years (1 point). We internally validated the BDR score using k-fold cross validation (k = 8) and externally validated the score at an independent academic center. The main outcome was BD.

RESULTS

The development cohort included 362OHCA patients, of whom 18% (N = 58) experienced BD. Internal validation provided an area under the receiving operator characteristic curve (AUC) (95% CI) of 0.931 (0.905-0.957). In the validation cohort, 19.8% (N = 17) experienced BD. The AUC (95% CI) was 0.849 (0.765-0.933). In both cohorts, a BDR score >4 was the optimal cut off (sensitivity 0.903 and 0.882, specificity 0.830 and 0.652, in the development and validation cohorts respectively).

DISCUSSION

The BDR score identifies those at highest risk for BD after OHCA. Our data suggest that a BDR score >4 is the optimal cut off.

Association between sex and survival after out-of-hospital cardiac arrest: A systematic review and meta-analysis

The current literature on sex differences in 30-day survival following out-of-hospital cardiac arrest (OHCA) is conflicting, with 3 recent systematic reviews reporting opposing results. To address these contradictions, this systematic literature review and meta-analysis aimed to synthesize the literature on sex differences in survival after OHCA by including only population-based studies and through separate meta-analyses of crude and adjusted effect estimates. MEDLINE and Embase databases were systematically searched from inception to March 23, 2022 to identify observational studies reporting sex-specific 30-day survival or survival until hospital discharge after OHCA. Two meta-analyses were conducted. The first included unadjusted effect estimates of the association between sex and survival (comparing males vs females), whereas the second included effect estimates adjusted for possible mediating and/or confounding variables. The PROSPERO registration number was CRD42021237887, and the search identified 6712 articles. After the screening, 164 potentially relevant articles were identified, of which 26 were included. The pooled estimate for crude effect estimates (odds ratio [OR], 1.42; 95% confidence interval [CI], 1.22-1.66) indicated that males have a higher chance of survival after OHCA than females. However, the pooled estimate for adjusted effect estimates shows no difference in survival after OHCA between males and females (OR, 0.93; 95% CI, 0.84-1.03). Both meta-analyses involved high statistical heterogeneity between studies: crude pooled estimate I2 = 95.7%, adjusted pooled estimate I2 = 91.3%. There does not appear to be a difference in survival between males and females when effect estimates are adjusted for possible confounding and/or mediating variables in non-selected populations.

In-hospital mode of death after out-of-hospital cardiac arrest

Introduction

Factors associated with in-hospital mortality after out-of-hospital cardiac arrest (OHCA), such as mode of death and withdrawal of life-sustaining treatment (WLST), are not well established. This study aimed to compare clinical characteristics, timing of WLST and death, and precipitating aetiology between modes of death for OHCAs treated at hospital within a local health network.

Methods

Retrospective cohort study of adult non-traumatic OHCAs included in a hospital based OHCA registry between 2011 and 2016 and deceased at hospital discharge, excluding cases retrieved to external hospitals. Mode of death was defined as (1) cardiovascular instability, (2) non-neurological WLST, (3) neurological WLST, and (4) formal brain death. Relevant data were extracted from the registry and stratified according to mode of death and timing of death as early (within the emergency department) or late (after admission).

Results

Mode of death data was available for 69 early and 144 late deaths. Cardiovascular instability was the primary mode for 75% of early deaths, while 72% of late deaths were attributed to neurological injury (47% neurological WLST and 24% brain death, combined). Cardiovascular instability was associated with cardiac aetiology, brain death was associated with younger age and highest rates of organ donation, and neurological WLST was associated with highest rates of targeted temperature management, and longest time from arrest to death (p < 0.05).

Conclusions

This is the first study to compare clinical characteristics of adult patients resuscitated from OHCA according to in-hospital mode of death. A consensus on the definition of mode of death with standardised classification is needed.