Long-term outcomes after out-of-hospital cardiac arrest: a systematic review and meta-analysis

The quality of care and long-term mortality of out of hospital cardiac arrest survivors after acute myocardial infarction: a nationwide cohort study

AIMS

The long-term outcomes of out of hospital cardiac arrest (OHCA) survivors are not well known.

METHODS AND RESULTS

Using the Myocardial Ischaemia National Audit Project (MINAP) registry, linked to Office for National Statistics mortality data, we analysed 661 326 England, Wales, and Northern Ireland acute myocardial infarction (AMI) patients; 14 127 (2%) suffered OHCA and survived beyond 30 days of hospitalization. Patients dying within 30 days of admission were excluded. Mean follow-up for the patients included was 1500 days. Cox regression models were fitted, adjusting for demographics and management strategy. OHCA survivors were younger (in years) {64 [interquartile range (IQR) 54-72] vs. 70 (IQR 59-80), P < 0.001}, more often underwent invasive coronary angiography (88% vs. 71%, P < 0.001) and percutaneous coronary intervention (72% vs. 45%, P < 0.001). Overall, the risk of mortality for OHCA patients that survived past 30 days was lower than patients that did not suffer cardiac arrest [adjusted hazard ratio (HR) 0.91; 95% CI; 0.87-0.95, P < 0.001]. 'Excellent care' according to the mean opportunity-based quality indicator (OBQI) score compared to 'Poor care', predicted a reduced risk of long-term mortality post-OHCA for all patients (HR: 0.77, CI; 0.76-0.78, P < 0.001), more for STEMI patients (HR: 0.73, CI; 0.71-0.75, P < 0.001), but less significantly in NSTEMI patients (HR: 0.79, CI; 0.78-0.81, P < 0.001).

CONCLUSION

OHCA patients remain at significant risk of mortality in-hospital. However, if surviving over 30 days post-arrest, OHCA survivors have good longer-term survival up to 10 years compared to the general AMI population. Higher-quality inpatient care appears to improve long-term survival in all OHCA patients, more so in STEMI.

"Shrink back is not my intention": a qualitative exploration of Chinese security guards' experiences with bystander CPR

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) is a major public health burden worldwide. Promoting bystander cardiopulmonary resuscitation (B-CPR) is a key element in improving the survival rate of OHCA. The security guard is a specific population in China that plays a significant role as bystanders in public settings. However, less is known about their experiences regarding B-CPR intention and performance. This study aimed to explore the experiences and perspectives of Chinese security guards regarding B-CPR and identify barriers to its performance.

METHODS

Fifteen in-depth interviews were conducted with security guards in various public settings, including hospitals, residential living areas, office buildings, and public transportation stations. All interviews were audio recorded. Two researchers independently analyzed the transcripts through deductive and inductive content analysis. Informed by the "Intention-focused" model of B-CPR performance, deductive content analysis was initially performed to identify categories that align with the theoretical framework and thereby validate the theory. Subsequently, inductive content analysis was applied to code newly discovered content, therefore enriching the theory.

RESULTS

An "intention & performance-focused" model of B-CPR was developed. It was revealed that security personnel were more inclined to perform CPR without hesitation when the victim was a trusted individual. However, when faced with unfamiliar individuals, they tended to shrink back due to various barriers. Specifically, four layers of barriers to CPR performance were identified, encompassing security personnel factors, victim-related factors, organizational factors, and societal factors. Participants also shared their perspectives on the desired CPR training, including trainers, training contents, training formats, and training incentives.

CONCLUSION

Security guards should receive comprehensive CPR training to maximize their occupational value. In addition to strengthening CPR-related training, which includes theoretical knowledge and hands-on practice, psychological coping skills for managing overwhelming emotions and understanding relevant laws are also essential training elements that cannot be overlooked. When developing relevant intervention strategies, policies, and regulations, it's critical to consider the country's context and the cooperation of the organization where the security guard is employed. The model developed in this study can provide a reference for designing interventions and policy to improve the B-CPR intention and performance for other specific groups.

Feasibility and Safety of Targeted Temperature Management During Interhospital Transport of Post-Cardiac Arrest Patients

OBJECTIVES

Early initiation of targeted temperature management (TTM) is crucial for post-resuscitation care. Although TTM is initiated prior to transport and continued during interhospital transport (IHT), its feasibility and safety during IHT for cardiac arrest patients have not been thoroughly assessed. This study aims to evaluate the feasibility and safety of interhospital TTM for post-resuscitation patients.

METHODS

A retrospective analysis of post-cardiac arrest patients transported by a dedicated critical care transport team between January 2016 and April 2023 was conducted. Adult patients resuscitated from cardiac arrest without mental recovery were enrolled. The study population was divided into those who received TTM during IHT (IHT-TTM group) and those who did not (non-IHT-TTM group). The primary outcome was body temperature drop during transport, with hypotension, or desaturation during transport considered as secondary outcomes. Multivariable conditional logistic regression analysis was performed after frequency matching.

RESULTS

Among 593 post-cardiac arrest patients, 332 were included in the analysis after exclusions. Of these, 44 (13.3%) received TTM during IHT. Conditional logistic regression analysis showed significantly higher likelihood for a drop in body temperature during IHT for the IHT-TTM group, with an odds ratio (OR) of 12.91 (95%CI: 5.28-31.53). No significant association was found for hypotension (OR (95%CI): 0.72 (0.13-3.97)), or desaturation during IHT (0.65 (0.15-2.82)).

CONCLUSIONS

Administration of TTM during IHT for post-cardiac arrest patients appears to be feasible and safe. These findings support the implementation of dedicated critical care transport systems capable of providing TTM during IHT for post-cardiac arrest patients.

Bystander Response and Out-of-Hospital Cardiac Arrest Outcomes (Bro. Study) in 3 Gulf Countries: Protocol for a Prospective, Observational, International Collaboration Study

BACKGROUND

: Globally, there is significant variation in the out-of-hospital cardiac arrest (OHCA) survival rate. Early links in the chain of survival, including bystander cardiopulmonary resuscitation (CPR) and the use of an automated external defibrillator at the scene, are known to be of crucial importance, with strong evidence of increased survival rate with good neurological outcomes. The data from the Middle East are limited and report variable rates of bystander CPR and survival. It is crucial to get prospective, reliable data on bystander response in these regions to help plan interventions to improve bystander response and outcomes.

OBJECTIVE

This international collaborative study aims to describe the characteristics, including bystander interventions and outcomes, of OHCAs brought to hospitals enrolled in the study from Abu Dhabi, United Arab Emirates; Doha, Qatar; and Muscat, Oman. It also aims to describe the strength of the association between bystander response and OHCA outcomes, including the return of spontaneous circulation, survival to hospital admission, survival to discharge, and good neurological outcome at discharge in the local context of low bystander CPR rates.

METHODS

This multicenter, prospective, noninterventional observational study (Bro. Study) will be conducted at the emergency departments of 4 participating tertiary care hospitals in 3 countries. The data will be collected prospectively according to the Utstein style (a set of internationally accepted guidelines for uniform reporting of cardiac arrests) on demographic variables (age, sex, nationality, country, participating center, and comorbidities), peri-cardiac arrest variables (location, witnessed or not, bystander CPR, use of automated external defibrillator, time of emergency medical services arrival, initial rhythm, number of shocks, and time of prehospital CPR), and outcome variables (return of spontaneous circulation, survival to discharge, and neurological outcome at discharge and 3 months). Univariate and multivariate analysis with logistic regression models will be used to measure the strength of the association of bystander interventions with outcomes using SPSS (version 22).

RESULTS

Data collection began in November 2023 and will continue for 2 years, with publication expected by early 2026.

CONCLUSIONS

Bystander response to an OHCA is critical to a favorable outcome. The reliable, baseline bystander CPR data will be a cornerstone in the team's next planned projects, which are to qualitatively identify the barriers to bystander CPR, conduct a scoping review of community interventions in the Gulf and other Asian countries, and design and implement strategies to help improve the bystander CPR rate in the community.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/58780.

Willingness and skills among students from non-health academic fields in providing efficient basic life support

Education in basic life support is widely proposed to increase survival in out-of-hospital sudden cardiac arrest. The authors aimed to assess knowledge, skills, and attitudes, including willingness to help, regarding myocardial infarction and sudden cardiac arrest among university students of all fields of knowledge.

METHODS

An Ethical Research Committee approved this cross-sectional study. An electronic survey "KIDS SAVE LIVES BRAZIL" was sent to 58,862 students of 82 disciplines in three universities, aged ≥ 18 years. The survey covered three categories: knowledge, skills, and attitude. Each category was graded between 0 and 10 points (the highest).

RESULTS

Among students, 4,803 undergraduates (8.2 %) answered the survey, and were divided into three groups of disciplines: medicine (219, ∼21.7 years, 38 % male), other-healthcare (n = 1,058; ∼22.9 years; 36 % male), and non-health-care (n = 3,526; ∼22.9 years; 35 % male). All three groups showed significant differences between them (p < 0.001). The non-health-care compared with medicine and other healthcare groups showed, respectively, the lowest median scores (25 %‒75 %) in knowledge (4.0 [0.0‒9.3], 4.0 [4.0‒8.0], and 4.0 [4.0‒4.7]), skills (2.4 [1.2‒3.3], 6.4 [4.0‒8.3], 4.0 [2.4‒6.2]), and attitude (5.9 [5.9‒6.8], 7.3 [5.9‒7.3], and 7.3 [5.9‒7.3]).

CONCLUSION

University students who answered the e-survey have the willingness to help victims suffering from myocardial infarction or sustaining sudden cardiac arrest. However, non healthcare students markedly lack the knowledge and skills to perform cardiopulmonary resuscitation and automated external defibrillation. These findings reveal a stark difference in basic life support competencies between students in related healthcare fields and those in non-health fields, emphasizing the need for universal basic life support training.

Neuroprognostication, withdrawal of care and long-term outcomes after cardiopulmonary resuscitation

PURPOSE OF REVIEW

Survivors of cardiac arrest often have increased long-term risks of mortality and disability that are primarily associated with hypoxic-ischemic brain injury (HIBI). This review aims to examine health-related long-term outcomes after cardiac arrest.

RECENT FINDINGS

A notable portion of cardiac arrest survivors face a decline in their quality of life, encountering persistent physical, cognitive, and mental health challenges emerging years after the initial event. Within the first-year postarrest, survivors are at elevated risk for stroke, epilepsy, and psychiatric conditions, along with a heightened susceptibility to developing dementia. Addressing these challenges necessitates establishing comprehensive, multidisciplinary care systems tailored to the needs of these individuals.

SUMMARY

HIBI remains the leading cause of disability among cardiac arrest survivors. No single strategy is likely to improve long term outcomes after cardiac arrest. A multimodal neuroprognostication approach (clinical examination, imaging, neurophysiology, and biomarkers) is recommended by guidelines, but fails to predict long-term outcomes. Cardiac arrest survivors often experience long-term disabilities that negatively impact their quality of life. The likelihood of such outcomes implements a multidisciplinary care an integral part of long-term recovery.

Sex-specific health-related quality of life in survivors of cardiac arrest

Survival after out-of-hospital cardiac arrest (OHCA) remains low, although the number of survivors is increasing, and survivors are living longer. With increasing long-term survival, there is a need to understand health-related quality of life (HRQoL) measures. Although there are current recommendations for measuring HRQoL in OHCA survivors, there is significant heterogeneity in assessment timing and the measurement tools used to quantify HRQoL outcomes, making the interpretation and comparison of HRQoL difficult. Identifying groups of survivors of OHCA with poor HRQoL measures could be used for targeted intervention studies. Sex differences in OHCA resuscitation characteristics, post-cardiac arrest treatment, and short-term survival outcomes are well-documented, although variability in study methods and statistical adjustments appear to affect study results and conclusions. It is unclear whether sex differences exist in HRQoL among OHCA survivors and if study methods and statistical adjustment for patient characteristics or arrest circumstances impact the results. In this narrative review article, we provide an overview of the assessment of HRQoL and the main domains of HRQoL. We summarize the literature regarding sex differences in HRQoL in OHCA survivors. Few multivariable-adjusted studies reported HRQoL sex differences and there was significant heterogeneity in study size, timing of assessment, and domains measured and reported. What is reported suggests females have worse HRQoL than males, especially in the domains of physical function and mental health, but results should be interpreted with caution. Lastly, we discuss the challenges of a non-uniform approach to measurement and future directions for assessing and improving HRQoL in OHCA survivors.

Effect of timing of advanced life support on out-of-hospital cardiac arrests at home

AIM

In cases of out-of-hospital cardiac arrests (OHCA) occurring at home, Japanese emergency medical services personnel decide whether to provide treatment on the scene or during transport based on their judgment. This study aimed to evaluate the association between the timing of advanced life support (ALS) (i.e., endotracheal intubation [ETI] or adrenaline administration) for OHCA at home and prognosis.

METHOD

This retrospective cohort study used data from the Japan Utstein Registry and emergency transport data collected from patients who underwent pre-hospital ETI (n = 6806) and received adrenaline (n = 22,636) between 2016 and 2019. The timing of ETI or adrenaline administration was determined as "on the scene" or "in the ambulance." Multiple logistic regression analysis was used to estimate the association among the timing of ALS implementation, pre-hospital return of spontaneous circulation (ROSC), and survival at 1 month.

RESULT

ETI on the scene was significantly positively associated with pre-hospital ROSC (adjusted odds ratio [AOR], 1.81; 95% confidence interval [CI], 1.57-2.09) and survival at 1 month (AOR, 1.81; 95% CI, 1.47-2.23). Adrenaline administration on the scene was significantly positively associated with pre-hospital ROSC (AOR, 2.51; 95% CI, 2.33-2.70) and survival at 1 month (AOR, 2.13; 95% CI, 1.89-2.40).

CONCLUSION

Our analysis suggests performing ALS on the scene was associated with pre-hospital ROSC and survival at 1 month. Further efforts are needed to increase the rate of ALS implementation on the scene by emergency life-saving technicians.

Long-term survival following out-of-hospital cardiac arrest in women and men: Influence of comorbidities, social characteristics, and resuscitation characteristics

AIM

We aimed to study sex differences in long-term survival following out-of-hospital cardiac arrest (OHCA) compared to the general population, and determined associations for comorbidities, social characteristics, and resuscitation characteristics with survival in women and men separately.

METHODS

We followed 2,452 Danish (530 women and 1,922 men) and 1,255 Dutch (259 women and 996 men) individuals aged ≥25 years, who survived 30 days post-OHCA in 2009-2015, until 2019. Using Poisson regression analyses we assessed sex differences in long-term survival and sex-specific associations of characteristics mutually adjusted, and compared survival with an age- and sex-matched general population. The potential predictive value was assessed with the Concordance-index.

RESULTS

Post-OHCA survival was longer in women than men (adjusted incidence rate ratio (IRR) for mortality 0.74, 95%CI 0.61-0.89 in Denmark; 0.86, 95%CI 0.65-1.15 in the Netherlands). Both sexes had a shorter survival than the general population (e.g., IRR for mortality 3.07, 95%CI 2.55-3.70 and IRR 2.15, 95%CI 1.95-2.37 in Danish women and men). Higher age, glucose lowering medication, no dyslipidaemia medication, unemployment, and a non-shockable initial rhythm were associated with shorter survival in both sexes. Cardiovascular medication, depression/anxiety medication, living alone, low household income, and residential OHCA location were associated with shorter survival in men. Not living with children and bystander cardiopulmonary resuscitation provision were associated with shorter survival in women. The Concordance-indexes ranged from 0.51 to 0.63.

CONCLUSIONS

Women survived longer than men post-OHCA. Several characteristics were associated with long-term post-OHCA survival, with some sex-specific characteristics. In both sexes, these characteristics had low predictive potential.

Socioeconomic disadvantage and long-term survival duration in out-of-hospital cardiac arrest patients: A population-based cohort study

Background

Socioeconomic status (SES) is a well-established determinant of cardiovascular health. However, the relationship between SES and clinical outcomes in long-term out-of-hospital cardiac arrest (OHCA) is less well-understood. The Singapore Housing Index (SHI) is a validated building-level SES indicator. We investigated whether SES as measured by SHI is associated with long-term OHCA survival in Singapore.

Methods

We conducted an open cohort study with linked data from the Singapore Pan-Asian Resuscitation Outcomes Study (PAROS), and the Singapore Registry of Births and Deaths (SRBD) from 2010 to 2020. We fitted generalized structural equation models, calculating hazard ratios (HRs) using a Weibull model. We constructed Kaplan-Meier survival curves and calculated the predicted marginal probability for each SHI category.

Results

We included 659 cases. In both univariable and multivariable analyses, SHI did not have a significant association with survival. Indirect pathways of SHI mediated through covariates such as Emergency Medical Services (EMS) response time (HR of low-medium, high-medium and high SHI when compared to low SHI: 0.98 (0.88-1.10), 1.01 (0.93-1.11), 1.02 (0.93-1.12) respectively), and age of arrest (HR of low-medium, high-medium and high SHI when compared to low SHI: 1.02 (0.75-1.38), 1.08 (0.84-1.38), 1.18 (0.91-1.54) respectively) had no significant association with OHCA survival. There was no clear trend in the predicted marginal probability of survival among the different SHI categories.

Conclusions

We did not find a significant association between SES and OHCA survival outcomes in residential areas in Singapore. Among other reasons, this could be due to affordable healthcare across different socioeconomic classes.

Systematic Review on the Worldwide Disparities in the Frequency and Results of Emergency Medical Services (EMS) and Response to Out-of-Hospital Cardiac Arrest (OHCA)

This systematic analysis aimed to analyze the key patterns and tendencies regarding bystander interventions, emergency medical service (EMS) systems, dispatcher support, regional and temporal differences, and the influence of national efforts on survival rates in out-of-hospital cardiac arrest (OHCA). The studies published between 2010 and 2024 examining outcomes of OHCA, interventions by bystanders, and variables linked to OHCA were included in this research. The inclusion process was done under Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), where publications (n = 24) from various geographical locations, including a wide range of research methodologies, were included for this research. The thematic analysis used for the data analysis shows that bystander cardiopulmonary resuscitation (CPR) enhances the chances of survival. The effectiveness of the EMS system, the assistance offered by dispatchers, and the inclusion of doctors in ambulance services are essential components in the management of OHCA. Regional and temporal variations highlight disparities in resuscitation protocols, emphasizing the need for adaptable approaches. Observations from statewide endeavors emphasize the impact of these activities in fostering a culture of prompt bystander intervention. This systematic review presents a comprehensive analysis of research conducted globally, providing a thorough insight into the variables that influence survival rates in instances of OHCA. The review recognizes the importance of bystander CPR and effective EMS services, while also bringing novel perspectives, such as gender disparities and geographical variations that contribute to the existing body of research. Despite possible variances in the studies and biases, the findings underscore the need for tailored therapies and ongoing research to optimize strategies for controlling OHCA and improving survival rates.

Post-intensive care syndrome and health-related quality of life in long-term survivors of cardiac arrest: a prospective cohort study

Patients discharged from intensive care are at risk for post-intensive care syndrome (PICS), which consists of physical, psychological, and/or neurological impairments. This study aimed to analyze PICS at 24 months follow-up, to identify potential risk factors for PICS, and to assess health-related quality of life in a long-term cohort of adult cardiac arrest survivors. This prospective cohort study included adult cardiac arrest survivors admitted to the intensive care unit of a Swiss tertiary academic medical center. The primary endpoint was the prevalence of PICS at 24 months follow-up, defined as impairments in physical (measured through the European Quality of Life 5-Dimensions-3-Levels instrument [EQ-5D-3L]), neurological (defined as Cerebral Performance Category Score > 2 or Modified Rankin Score > 3), and psychological (based on the Hospital Anxiety and Depression Scale and the Impact of Event Scale-Revised) domains. Among 107 cardiac arrest survivors that completed the 2-year follow-up, 46 patients (43.0%) had symptoms of PICS, with 41 patients (38.7%) experiencing symptoms in the physical domain, 16 patients (15.4%) in the psychological domain, and 3 patients (2.8%) in the neurological domain. Key predictors for PICS in multivariate analyses were female sex (adjusted odds ratio [aOR] 3.17, 95% CI 1.08 to 9.3), duration of no-flow interval during cardiac arrest (minutes) (aOR 1.17, 95% CI 1.02 to 1.33), post-discharge job-loss (aOR 31.25, 95% CI 3.63 to 268.83), need for ongoing psychological support (aOR 3.64, 95% CI 1.29 to 10.29) or psychopharmacologic treatment (aOR 9.49, 95% CI 1.9 to 47.3), and EQ-visual analogue scale (points) (aOR 0.88, 95% CI 0.84 to 0.93). More than one-third of cardiac arrest survivors experience symptoms of PICS 2 years after resuscitation, with the highest impairment observed in the physical and psychological domains. However, long-term survivors of cardiac arrest report intact health-related quality of life when compared to the general population. Future research should focus on appropriate prevention, screening, and treatment strategies for PICS in cardiac arrest patients.

Return to Work After Refractory Out-of-Hospital Cardiac Arrest in Patients Managed With or Without Extracorporeal Cardiopulmonary Resuscitation: A Nationwide Register-Based Study

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR) is increasingly used for refractory out-of-hospital cardiac arrest (OHCA). However, survivors managed with ECPR are at risk of poor functional status. The purpose of this study was to investigate return to work (RTW) after refractory OHCA.

METHODS AND RESULTS

Of 44 360 patients with OHCA in the period of 2011 to 2020, this nationwide registry-based study included 805 patients with refractory OHCA in the working age (18-65 years) who were employed before OHCA (2% of the total OHCA cohort). Demographics, prehospital characteristics, status at hospital arrival, employment status, and survival were retrieved through the Danish national registries. Sustainable RTW was defined as RTW for ≥6 months without any long sick leave relapses. Median follow-up time was 4.1 years. ECPR and standard advanced cardiovascular life support were applied in 136 and 669 patients, respectively. RTW 1 year after OHCA was similar (39% versus 54%; P=0.2) and sustainable RTW was high in both survivors managed with ECPR and survivors managed with standard advanced cardiovascular life support (83% versus 85%; P>0.9). Younger age and shorter length of hospitalization were associated with RTW in multivariable Cox analysis, whereas ECPR was not.

CONCLUSIONS

In refractory OHCA-patients employed prior to OHCA, approximately 1 out of 2 patients were employed after 1 year with no difference between patients treated with ECPR or standard advanced cardiovascular life support. Younger age and shorter length of hospitalization were associated with RTW while ECPR was not.

Misconceptions and do-not-resuscitate preferences of healthcare professionals commonly involved in cardiopulmonary resuscitations: A national survey

Aims

To assess the DNR preferences of critical care-, anesthesia- and emergency medicine practitioners, to identify factors influencing decision-making, and to raise awareness for misconceptions concerning CPR outcomes.

Methods

A nationwide multicenter survey was conducted in Switzerland confronting healthcare professionals with a case vignette of an adult patient with an out-of-hospital cardiac arrest (OHCA). The primary outcome was the rate of DNR Code Status vs. CPR Code Status when taking the perspective from a clinical case vignette of a 70-year-old patient. Secondary outcomes were participants' personal preferences for DNR and estimates of survival with good neurological outcome after in- and out-of-hospital cardiac arrest.

Results

Within 1803 healthcare professionals, DNR code status was preferred in 85% (n = 1532) in the personal perspective of the case vignette and 53.2% (n = 932) when making a decision for themselves. Main predictors for a DNR Code Status regarding the case vignette included preferences for DNR Code Status for themselves (n [%] 896 [58.5] vs. 87 [32.1]; adjusted odds ratio [OR] 2.97, 95% confidence interval [CI] 2.25-3.92; p < 0.001) and lower estimated OHCA survival (mean [±SD] 12.3% [±11.8] vs. 14.7%[±12.8]; adjusted OR 0.98, 95% CI 0.97-0.99; p = 0.001). Physicians chose a DNR order more often when compared to nurses and paramedics.

Conclusions

The estimation of outcomes following cardiac arrest and personal living conditions are pivotal factors influencing code status preferences in healthcare professionals. Healthcare professionals should be aware of cardiac arrest prognosis and potential implications of personal preferences when engaging in code status- and end-of-life discussions with patients and their relatives.

Incidence and Long-Term Outcomes of Acute Myocardial Infarction Among Survivors of Out-of-Hospital Cardiac Arrest

BACKGROUND

Despite the increasing long-term survival after out-of-hospital cardiac arrest (OHCA), the risk of subsequent acute myocardial infarction (AMI) remains poorly understood. We aimed to determine the incidence, predictors, and long-term outcomes of AMI among survivors of OHCA.

METHODS AND RESULTS

We assembled a retrospective cohort of 882 patients with OHCA who survived to 30 days or discharge from the hospital between 2010 and 2019. Survivors of OHCA had an increased risk of subsequent AMI, defined as AMI occurring 30 days after index OHCA or following discharge from the hospital after OHCA, compared with the general population when matched for age and sex (standardized incidence ratio, 4.64 [95% CI, 3.52-6.01]). Age-specific risks of subsequent AMI for men (standardized incidence ratio, 3.29 [95% CI, 2.39-4.42]) and women (standardized incidence ratio, 6.15 [95% CI, 3.27-10.52]) were significantly increased. A total of 7.2%, 8.3%, and 14.3% of survivors of OHCA had a subsequent AMI at 3 years, 5 years, and end of follow-up, respectively. Age at OHCA (hazard ratio [HR], 1.04 [95% CI, 1.02-1.06]) and past medical history of prior AMI, defined as any AMI preceding or during the index OHCA event (HR, 1.84 [95% CI, 1.05-3.22]), were associated with subsequent AMI, while an initial shockable rhythm was not (HR, 1.00 [95% CI, 0.52-1.94]). Survivors of OHCA with subsequent AMI had a higher risk of death (HR, 1.58 [95% CI, 1.12-2.22]) than those without.

CONCLUSIONS

Survivors of OHCA are at an increased risk of subsequent AMI compared with the general population. Prior AMI, but not an initial shockable rhythm, increases this risk, while subsequent AMI predicts death. Preventive measures for AMI including cardiovascular risk factor control and revascularization may thus improve outcomes in selected patients with cardiac pathogenesis.

Outcomes of out-of-hospital cardiac arrest in Ireland 2012-2020: Protocol for an observational study

Background

Out-of-hospital cardiac arrest (OHCA) is a leading cause of preventable mortality that now affects almost 3,000 people each year in Ireland. Survival is low at 6-7%, compared to a European average of 8%. The Irish Out-of-Hospital Cardiac Registry (OHCAR) prospectively gathers data on all OHCA in Ireland where emergency medical services attempted resuscitation.The Irish health system has undergone several developments that are relevant to OHCA care in the period 2012-2020. OHCAR data provides a means of exploring temporal trends in OHCA incidence, care, and outcomes over time. It also provides a means of exploring whether system developments were associated with a change in key outcomes.This research aims to summarise key trends in available OHCAR data from the period 2012 - 2020, to explore and model predictors of bystander CPR, bystander defibrillation, and survival, and to explore the hypothesis that significant system level temporal developments were associated with improvements in these outcomes.

Methods

The following protocol sets out the relevant background and research approach for an observational study that will address the above aims. Key trends in available OHCAR data (2012 - 2020) will be described and evaluated using descriptive summaries and graphical displays. Multivariable logistic regression will be used to model predictors of 'bystander CPR', 'bystander defibrillation' and 'survival to hospital discharge' and to explore the effects (if any) of system level developments in 2015/2016 and the COVID-19 pandemic (2020) on these outcomes.

Discussion

The findings of this research will be used to understand temporal trends in the care processes and outcomes for OHCA in Ireland over the period 2012-2020. The results can further be used to optimise future health system developments for OHCA in both Ireland and internationally.

Telephone-based evaluation of cognitive impairment and mood disorders in cardiac arrest survivors with good neurologic outcomes: a retrospective cohort study

This study determined the occurrence of cognitive impairment and mood disorders in out-of-hospital cardiac arrest (OHCA) survivors with good neurologic outcomes. We performed a retrospective, cross-sectional, single-center study with a total of 97 patients. We evaluated cognitive dysfunction via the Montreal Cognitive Assessment and Alzheimer's disease-8 mood disorders via the Patient Health Questionnaire-9 and the Hospital Anxiety and Depression Scale. We measured quality of life with the European Quality of Life 5-Dimension 5-Levels questionnaire. Cognitive impairment and mood disorders were common among patients with good neurologic recovery. There were 23 patients who experienced cognitive impairments (23.7%) and 28 who suffered from mood disorders (28.9%). Age (adjusted OR 1.07, 95% CI 1.02-1.12), mood disorders (adjusted OR 22.80, 95% CI 4.84-107.49) and hospital length of stay (adjusted OR 1.05, 95% CI 1.02-1.09) were independent risk factors for cognitive impairment. The occurrence of cognitive impairments (adjusted OR 9.94, 95% CI 2.83-35.97) and non-cardiac causes of cardiac arrest (adjusted OR 11.51, 95% CI 3.15-42.15) were risk factors for mood disorders. Quality of life was significantly lower in the OHCA survivors with each disorder than the healthy individuals. Routine screening and intervention are needed for OHCA survivors.

Association of Socioeconomic Status With Long-Term Outcome in Survivors After Out-of-Hospital Cardiac Arrest: Nationwide Population-Based Longitudinal Study

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) is a major public health problem and a leading cause of death worldwide. Previous studies have focused on improving the survival of people who have had OHCA by analyzing short-term survival outcomes, such as the return of spontaneous circulation, 30-day survival, and survival to discharge. Research has been conducted on prehospital prognostic factors to improve the survival of patients with OHCA, among which the association between socioeconomic status (SES) and survival has been reported. SES could affect bystander cardiopulmonary resuscitation rates and whether OHCA is witnessed, and low cardiopulmonary resuscitation education rates are associated with low SES. It has been reported that areas with high SES have shorter hospital transfer times and more public defibrillators per person. Previous studies have shown the impact of SES disparities on the short-term survival of patients with OHCA. However, understanding the impact of SES on the long-term prognosis of OHCA survivors remains limited. As long-term outcomes are more indicative of a patient's ongoing health care needs and the burden on public health than short-term outcomes, understanding the long-term prognosis of OHCA survivors is important.

OBJECTIVE

This study aimed to identify whether SES influenced the long-term outcomes of OHCA.

METHODS

Using health claims data obtained from the National Health Insurance (NHI) service in Korea, we included OHCA survivors who were hospitalized between January 2005 and December 2015. The patients were divided into 2 groups: NHI and Medical Aid (MA) groups, with the MA group defined as having a low SES. Cumulative mortality was estimated using the Kaplan-Meier method, and a Cox proportional hazards model was used to evaluate the impact of SES on long-term mortality. A subgroup analysis was performed based on whether cardiac procedures were performed.

RESULTS

We followed 4873 OHCA survivors for up to 14 years (median of 3.3 years). The Kaplan-Meier survival curve showed that the MA group had a significantly decreased long-term survival rate compared to the NHI group. With an adjusted hazard ratio (aHR) of 1.52 (95% CI 1.35-1.72), low SES was associated with increased long-term mortality. The overall mortality rate of the patients who underwent cardiac procedures in the MA group was significantly higher than that of the NHI group (aHR 1.72, 95% CI 1.05-2.82). The overall mortality rate of patients without cardiac procedures was also increased in the MA group compared to the NHI group (aHR 1.39, 95% CI 1.23-1.58).

CONCLUSIONS

OHCA survivors with low SES had an increased risk of poor long-term outcomes compared with those with higher SES. OHCA survivors with low SES who have undergone cardiac procedures need considerable care for long-term survival.

“Do-not-resuscitate” preferences of the general Swiss population: Results from a national survey

AIMS

To assess the do-not-resuscitate preferences of the general Swiss population and to identify predictors influencing decision-making.

Methods

A nationwide web-based survey was conducted in Switzerland on a representative sample of the adult population. The primary endpoint was the preference for a "Do Not Resuscitate" order (DNR Code Status) vs. cardiopulmonary resuscitation (CPR Code Status) in a clinical case vignette of an out-of-hospital cardiac arrest. Secondary endpoint were participants' own personal preferences for DNR.

Results

1138 subjects participated in the web-based survey, 1044 were included in the final analysis. Preference for DNR code status was found in 40.5% (n = 423) in the case vignette and in 20.3% (n = 209) when making a personal decision for themselves. Independent predictors for DNR Code Status for the case vignette were: Personal preferences for their own DNR Code Status (adjusted OR 2.44, 95%CI 1.67 to 3.55; p < 0.001), intubation following respiratory failure (adjusted OR 1.95, 95%CI 1.20 to 3.18; p = 0.007), time-period after which resuscitation should not be attempted (adjusted OR 0.91, 95%CI 0.89 to 0.93); p < 0.001), and estimated chance of survival in case of a cardiac arrest (adjusted OR per decile 0.91, 95%CI 0.84 to 0.99, p = 0.02; which was overestimated by all participants.

Conclusions

Main predictors for a DNR Code Status were personal preferences and the overestimation of good neurological outcome after cardiac arrest. Overestimation of positive outcomes after cardiac arrest seems to influence patient opinion and should thus be addressed during code status discussions.

Determinants of health-related quality of life after out-of-hospital cardiac arrest (OHCA): A systematic review

OBJECTIVE

With a growing number of out-of-hospital cardiac arrest (OHCA) survivors globally, the focus of OHCA management has now broadened to survivorship. An outcome central to survivorship is health-related quality of life (HRQoL). This systematic review aimed to synthesise evidence related to the determinants of HRQoL of OHCA survivors.

METHODS

We systematically searched MEDLINE, Embase, and Scopus from inception to 15 August 2022 to identify studies investigating the association of at least one determinant and HRQoL in adult OHCA survivors. All articles were independently reviewed by two investigators. We abstracted data pertaining to determinants and classified them using a well-established HRQoL theoretical framework - the Wilson and Cleary (revised) model.

RESULTS

31 articles assessing a total of 35 determinants were included. Determinants were classified into the five domains in the HRQoL model. 26 studies assessed determinants related to individual characteristics (n=3), 12 studied biological function (n=7), nine studied symptoms (n=3), 16 studied functioning (n=5), and 35 studied characteristics of the environment (n=17). In studies that included multivariable analyses, most reported that individual characteristics (older age, female sex), symptoms (anxiety, depression), and functioning (impaired neurocognitive function) were significantly associated with poorer HRQoL.

CONCLUSIONS

Individual characteristics, symptoms, and functioning played significant roles in explaining the variability in HRQoL. Significant non-modifiable determinants such as age and sex could be used to identify populations at risk of poorer HRQoL, while significant modifiable determinants such as psychological health and neurocognitive functioning could serve as targets for post-discharge screening and rehabilitation plans. PROSPERO registration number: CRD42022359303.

External validation of the PROLOGUE score to predict neurological outcome in adult patients after cardiac arrest: a prospective cohort study

BACKGROUND

The PROLOGUE score (PROgnostication using LOGistic regression model for Unselected adult cardiac arrest patients in the Early stages) is a novel prognostic model for the prediction of neurological outcome after cardiac arrest, which showed exceptional performance in the internal validation. The aim of this study is to validate the PROLOGUE score in an independent cohort of unselected adult cardiac arrest patients and to compare it to the thoroughly validated Out-of-Hospital Cardiac Arrest (OHCA) and Cardiac Arrest Hospital Prognosis (CAHP) scores.

METHODS

This study included consecutive adult cardiac arrest patients admitted to the intensive care unit (ICU) of a Swiss tertiary teaching hospital between October 2012 and July 2022. The primary endpoint was poor neurological outcome at hospital discharge, defined as a Cerebral Performance Category (CPC) score of 3 to 5 including death.

RESULTS

Of 687 patients included in the analysis, 321 (46.7%) survived to hospital discharge with good neurological outcome, 68 (9.9%) survived with poor neurological outcome and 298 (43.4%) died. The PROLOGUE score showed an area under the receiver operating characteristic curve (AUROC) of 0.83 (95% CI 0.80 to 0.86) and good calibration for the prediction of the primary outcome. The OHCA and CAHP score showed similar performance (AUROC 0.83 and 0.84 respectively), the differences between the three scores were not significant (p = 0.495). In a subgroup analysis, the PROLOGUE score performed equally in out-of-hospital and in-hospital cardiac arrest patients whereas the OHCA and CAHP score performed significantly better in OHCA patients.

CONCLUSION

The PROLOGUE score showed good prognostic accuracy for the early prediction of neurological outcome in adult cardiac arrest survivors in our cohort and might support early goals-of-care discussions in the ICU. Trial registration Not applicable.

Delayed neurologic improvement and long-term survival of patients with poor neurologic status after out-of-hospital cardiac arrest: a retrospective cohort study in Japan

AIM

To assess survival duration and frequency of delayed neurologic improvement in patients with poor neurologic status at discharge from emergency hospitals after out-of-hospital cardiac arrest (OHCA).

METHODS

This retrospective cohort study included OHCA patients admitted to two tertiary emergency hospitals in Japan between January 2014 and December 2020. Pre-hospital, tertiary emergency hospital, and post-acute care hospital data, were retrospectively collected by reviewing medical records. Neurologic improvements were defined as an improvement of Cerebral Performance Category (CPC) scores from 3 or 4 at hospital discharge to 1 or 2. The primary outcome was neurologic improvement after discharge, while the secondary outcome was survival time after cardiac arrest.

RESULTS

Of all patients (n=1,012) admitted to tertiary emergency hospitals after OHCA during the observation period, 239 with CPC 3 or 4 at discharge were included, and all were Japanese. Median age was 75 years, 64% were male, and 31% had initially shockable rhythms. Neurologic improvements were observed in nine patients (3.6%), higher in CPC 3 (31%) than CPC 4 (1.3%) patients, but not after 6 months from cardiac arrest. The median survival time after cardiac arrest was 386 days (95% confidence interval: 303-469).

CONCLUSION

Survival probability in patients with CPC 3 or 4 was 50% at 1-year and 20% at 3-year. Neurologic improvements were observed in 3.6% patients, higher in CPC 3 than in CPC 4 patients. During the first 6 months after OHCA, the neurologic status may improve in patients with CPC 3 or 4.

Global prevalence of basic life support training: A systematic review and meta-analysis

BACKGROUND AND AIMS

Out-of-hospital cardiac arrest exerts a large disease burden, which may be mitigated by bystander cardiopulmonary resuscitation and automated external defibrillation. We aimed to estimate the global prevalence and distribution of bystander training among laypersons, which are poorly understood, and to identify their determinants.

METHODS

We searched electronic databases for cross-sectional studies reporting the prevalence of bystander training from representative population samples. Pooled prevalence was calculated using random-effects models. Key outcome was cardiopulmonary resuscitation training (training within two-years and those who were ever trained). We explored determinants of interest using subgroup analysis and meta-regression.

RESULTS

28 studies were included, representing 53,397 laypersons. Among national studies, the prevalence of cardiopulmonary resuscitation training within two-years and among those who were ever trained, and automated external defibrillator training was 10.02% (95% CI 6.60-14.05) and 39.64% (95%CI 29.11-50.67), and 15.70% (95% CI 10.17-22.18) respectively. Subgroup analyses by continent revealed pooled prevalence estimates of 31.58% (95%CI 18.70-46.09), 52.62% (95%CI 38.40-66.63), 18.93 (95%CI 0.00-62.94), 64.97% (95%CI 64.00-65.93), and 50.56% (95%CI 47.57-53.54) in Asia, Europe, Middle East, North America, and Oceania respectively, with significant subgroup differences (p<0.01). A country's income and cardiopulmonary resuscitation training (ever trained) (p=0.033) were positively correlated. Similarly, this prevalence was higher among the employed (p<0.00001) and highly educated (p<0.00001).

CONCLUSIONS

Large regional variation exists in data availability and bystander training prevalence. Socioeconomic status correlated with prevalence of bystander training, and regional disparities were apparent between continents. Bystander training should be promoted, particularly in Asia, Middle East, and low-income regions. Data availability should be encouraged from under-represented regions.

Predicting neurological outcome after cardiac arrest by combining computational parameters extracted from standard and deviant responses from auditory evoked potentials

Background

Despite multimodal assessment (clinical examination, biology, brain MRI, electroencephalography, somatosensory evoked potentials, mismatch negativity at auditory evoked potentials), coma prognostic evaluation remains challenging.

Methods

We present here a method to predict the return to consciousness and good neurological outcome based on classification of auditory evoked potentials obtained during an oddball paradigm. Data from event-related potentials (ERPs) were recorded noninvasively using four surface electroencephalography (EEG) electrodes in a cohort of 29 post-cardiac arrest comatose patients (between day 3 and day 6 following admission). We extracted retrospectively several EEG features (standard deviation and similarity for standard auditory stimulations and number of extrema and oscillations for deviant auditory stimulations) from the time responses in a window of few hundreds of milliseconds. The responses to the standard and the deviant auditory stimulations were thus considered independently. By combining these features, based on machine learning, we built a two-dimensional map to evaluate possible group clustering.

Results

Analysis in two-dimensions of the present data revealed two separated clusters of patients with good versus bad neurological outcome. When favoring the highest specificity of our mathematical algorithms (0.91), we found a sensitivity of 0.83 and an accuracy of 0.90, maintained when calculation was performed using data from only one central electrode. Using Gaussian, K-neighborhood and SVM classifiers, we could predict the neurological outcome of post-anoxic comatose patients, the validity of the method being tested by a cross-validation procedure. Moreover, the same results were obtained with one single electrode (Cz).

Conclusion

statistics of standard and deviant responses considered separately provide complementary and confirmatory predictions of the outcome of anoxic comatose patients, better assessed when combining these features on a two-dimensional statistical map. The benefit of this method compared to classical EEG and ERP predictors should be tested in a large prospective cohort. If validated, this method could provide an alternative tool to intensivists, to better evaluate neurological outcome and improve patient management, without neurophysiologist assistance.

Long term survival and disease burden from out-of-hospital cardiac arrest in Singapore: a population-based cohort study

Background

Understanding the long-term outcomes and disability-adjusted life years (DALY) after out-of-hospital cardiac arrest (OHCA) is important to understand the overall health and disease burden of OHCA respectively, but data in Asia remains limited. We aimed to quantify long-term survival and the annual disease burden of OHCA within a national multi-ethnic Asian cohort.

Methods

We conducted an open cohort study linking the Singapore Pan-Asian Resuscitation Outcomes Study (PAROS) and the Singapore Registry of Births and Deaths from 2010 to 2019. We performed Cox regression, constructed Kaplan-Meier curves, and calculated DALYs and standardised mortality ratios (SMR) for each year of follow-up.

Results

We analysed 802 cases. The mean age was 56.0 (SD 17.8). Most were male (631 cases, 78,7%) and of Chinese ethnicity (552 cases, 68.8%). At one year, the SMR was 14.9 (95% CI:12.5-17.8), decreasing to 1.2 (95% CI:0.7-1.8) at three years, and 0.4 (95% CI:0.2-0.8) at five years. Age at arrest (HR:1.03, 95% CI:1.02-1.04, p < 0.001), shockable presenting rhythm (HR:0.75, 95% CI:0.52-0.93, p = 0.015) and CPC category (HR:4.62, 95% CI:3.17-6.75, p < 0.001) were independently associated with mortality. Annual DALYs due to OHCA varied from 304.1 in 2010 to 849.7 in 2015, then 547.1 in 2018. Mean DALYs decreased from 12.162 in 2010 to 3.599 in 2018.

Conclusions

OHCA survivors had an increased mortality rate for the first three years which subsequently normalised compared to that of the general population. Annual OHCA disease burden in DALY trended downwards from 2010 to 2018. Improved surveillance and OHCA treatment strategies may improve long-term survivorship and decrease its global burden.

Funding

National Medical Research Council, Singapore, under the Clinician Scientist Award (NMRC/CSA-SI/0014/2017) and the Singapore Translational Research Investigator Award (MOH-000982-01).

Post-intensive care syndrome in out-of-hospital cardiac arrest patients: A prospective observational cohort study

INTRODUCTION

Intensive care unit patients are at risk for post-intensive care syndrome (PICS), which includes psychological, physical and/or cognitive sequelae after their hospital stay. Our aim was to investigate PICS in adult patients with out-of-hospital cardiac arrest (OHCA).

METHODS

In this prospective observational cohort study, we assessed risks for PICS at 3 and 12-month follow-up within the following domains: a) physical impairment (EuroQol [EQ-5D-3L]), b) cognitive functioning (Cerebral Performance Category [CPC] score >1, modified Rankin Scale [mRS] >2) and c) psychological burden (Hospital Anxiety and Depression Scale [HADS], Impact of Event Scale-Revised [IES-R]).

RESULTS

At 3 months, 69/139 patients (50%) met the definition of PICS including 37% in the physical domain, 25% in the cognitive domain and 13% in the psychological domain. Intubation (OR 2.3, 95%CI 1.1 to 5,0 p = 0.03), sedatives (OR 3.4, 95%CI 1 to 11, p = 0.045), mRS at discharge (OR 4.3, 95%CI 1.70 to 11.01, p = 0.002), CPC at discharge (OR 3.3, 95%CI 1.4 to 7.6, p = 0.005) and post-discharge work loss (OR 13.4, 95%CI 1.7 to 107.5, p = 0.014) were significantly associated with PICS. At 12 months, 52/110 (47%) patients had PICS, which was associated with prolonged duration of rehabilitation, higher APACHE scores, and higher mRS and CPC scores at hospital discharge.

CONCLUSIONS

Nearly half of long-term OHCA survivors show PICS after 3 and 12 months. These high numbers call for more emphasis on appropriate screening and treatment in this patient population. Future studies should evaluate whether early identification of these patients enables preventive strategies and treatment options.

The Role of Drones in Out-of-Hospital Cardiac Arrest: A Scoping Review

Drones may be able to deliver automated external defibrillators (AEDs) directly to bystanders of out-of-hospital cardiac arrest (OHCA) events, improving survival outcomes by facilitating early defibrillation. We aimed to provide an overview of the available literature on the role and impact of drones in AED delivery in OHCA. We conducted this scoping review using the PRISMA-ScR and Arksey and O'Malley framework, and systematically searched five bibliographical databases (Medline, EMBASE, Cochrane CENTRAL, PsychInfo and Scopus) from inception until 28 February 2022. After excluding duplicate articles, title/abstract screening followed by full text review was conducted by three independent authors. Data from the included articles were abstracted and analysed, with a focus on potential time savings of drone networks in delivering AEDs in OHCA, and factors that influence its implementation. Out of the 26 included studies, 23 conducted simulations or physical trials to optimise drone network configuration and evaluate time savings from drone delivery of AEDs, compared to the current emergency medical services (EMS), along with 1 prospective trial conducted in Sweden and 2 qualitative studies. Improvements in response times varied across the studies, with greater time savings in rural areas. However, emergency call to AED attachment time was not reduced in the sole prospective study and a South Korean study that accounted for weather and topography. With growing interest in drones and their potential use in AED delivery spurring new research in the field, our included studies demonstrate the potential advantages of unmanned aerial vehicle (UAV) network implementation in controlled environments to deliver AEDs faster than current EMS. However, for these time savings to translate to reduced times to defibrillation and improvement in OHCA outcomes, careful evaluation and addressing of real-world delays, challenges, and barriers to drone use in AED delivery is required.

Long-Term Outcomes after Non-Traumatic Out-of-Hospital Cardiac Arrest in Pediatric Patients: A Systematic Review

Long-term outcomes after non-traumatic pediatric out-of-hospital cardiac arrest (OHCA) are not well understood. This systematic review aimed to summarize long-term outcomes (1 year and beyond), including overall survival, survival with favorable neurological outcomes, and health-related quality of life (HRQoL) outcomes) amongst pediatric OHCA patients who survived to discharge. Embase, Medline, and The Cochrane Library were searched from inception to October 6, 2021. Studies were included if they reported outcomes at 1 year or beyond after pediatric OHCA. Data abstraction and quality assessment was conducted by three authors independently. Qualitative outcomes were reported systematically. Seven studies were included, and amongst patients that survived to hospital discharge or to 30 days, longer-term survival was at least 95% at 24 months of follow up. A highly variable proportion (range 10–71%) of patients had favorable neurological outcomes at 24 months of follow up. With regard to health-related quality of life outcomes, at a time point distal to 1 year, at least 60% of pediatric non-traumatic OHCA patients were reported to have good outcomes. Our study found that at least 95% of pediatric OHCA patients, who survived to discharge, survived to a time point distal to 1 year. There is a general paucity of data surrounding the pediatric OHCA population.

Comparison of different clinical risk scores to predict long-term survival and neurological outcome in adults after cardiac arrest: results from a prospective cohort study

Background

Several scoring systems have been used to predict short-term outcome in patients with out-of-hospital cardiac arrest (OHCA), including the disease-specific OHCA and CAHP (Cardiac Arrest Hospital Prognosis) scores, as well as the general severity-of-illness scores Acute Physiology and Chronic Health Evaluation II (APACHE II) and Simplified Acute Physiology Score II (SAPS II). This study aimed to assess the prognostic performance of these four scores to predict long-term outcomes (≥ 2 years) in adult cardiac arrest patients.

Methods

This is a prospective single-centre cohort study including consecutive cardiac arrest patients admitted to intensive care in a Swiss tertiary academic medical centre. The primary endpoint was 2-year mortality. Secondary endpoints were neurological outcome at 2 years post-arrest assessed by Cerebral Performance Category with CPC 1–2 defined as good and CPC 3–5 as poor neurological outcome, and 6-year mortality.

Results

In 415 patients admitted to intensive care, the 2-year mortality was 58.1%, with 96.7% of survivors showing good neurological outcome. The 6-year mortality was 82.5%. All four scores showed good discriminatory performance for 2-year mortality, with areas under the receiver operating characteristics curve (AUROC) of 0.82, 0.87, 0.83 and 0.81 for the OHCA, CAHP, APACHE II and SAPS II scores. The results were similar for poor neurological outcome at 2 years and 6-year mortality.

Conclusion

This study suggests that two established cardiac arrest-specific scores and two severity-of-illness scores provide good prognostic value to predict long-term outcome after cardiac arrest and thus may help in early goals-of-care discussions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01048-y.

Association of High-Volume Centers With Survival Outcomes Among Patients With Nontraumatic Out-of-Hospital Cardiac Arrest: A Systematic Review and Meta-Analysis

Importance

Although high volume of cases of out-of-hospital cardiac arrest (OHCA) is a key feature of cardiac arrest centers, which have proven survival benefit, the role of center volume as an independent variable associated with improved outcomes is unclear.

Objective

To assess the association of high-volume centers with survival and neurological outcomes in nontraumatic OHCA.

Data Sources

Medline, Embase, and the Cochrane Central Register of Controlled Trials were searched from inception to October 11, 2021, for studies including adult patients with nontraumatic OHCA who were treated at high-volume vs non-high-volume centers.

Study Selection

Randomized clinical trials, nonrandomized studies of interventions, prospective cohort studies, and retrospective cohort studies were selected that met the following criteria: (1) adult patients with OHCA of nontraumatic etiology, (2) comparison of high-volume with low-volume centers, (3) report of a volume-outcome association, and (4) report of outcomes of interest. At least 2 authors independently reviewed each article, blinded to each other's decision.

Data Extraction and Synthesis

Data abstraction and quality assessment were independently conducted by 2 authors. Meta-analyses were performed for adjusted odds ratios (aORs) and crude ORs using a random-effects model. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline.

Main Outcomes and Measures

Survival and good neurological outcomes according to the Cerebral Performance Categories Scale at hospital discharge or 30 days.

Results

A total of 16 studies involving 82 769 patients were included. Five studies defined high volume as 40 or more cases of OHCA per year; 3 studies defined high volume as greater than 100 cases of OHCA per year. All other studies differed in definitions. Survival to discharge or 30 days improved with treatment at high-volume centers, regardless of whether aORs (1.28 [95% CI, 1.00-1.64]) or crude ORs (1.43 [95% CI, 1.09-1.87]) were pooled. There was no association between center volume and good neurological outcomes at 30 days or hospital discharge in patients with OHCA (aOR, 0.96 [95% CI, 0.77-1.20]).

Conclusions and Relevance

In this meta-analysis and systematic review, care at high-volume centers was associated with improved survival outcomes, even after adjustment for potential confounders, but was not associated with improved neurological outcomes for patients with nontraumatic OHCA. More studies evaluating the relative importance of center volume compared with other variables (eg, the availability of treatment modalities) associated with survival outcomes in patients with OHCA are required.