Outcome of out-of-hospital cardiac arrests in Beijing, China

Global Sex Disparities in Bystander Cardiopulmonary Resuscitation After Out-of-Hospital Cardiac Arrest: A Scoping Review

This scoping review collates evidence for sex biases in the receipt of bystander cardiopulmonary resuscitation (BCPR) among patients with out-of-hospital cardiac arrest patients globally. The MEDLINE, PsycINFO, CENTRAL, and Embase databases were screened for relevant literature, dated from inception to March 9, 2022. Studies evaluating the association between BCPR and sex/gender in patients with out-of-hospital cardiac arrest, except for pediatric populations and cardiac arrest cases with traumatic cause, were included. The review included 80 articles on BCPR in men and women globally; 58 of these studies evaluated sex differences in BCPR outcomes. Fifty-nine percent of the relevant studies (34/58) indicated that women are less likely recipients of BCPR, 36% (21/58) observed no significant sex differences, and 5% (3/58) reported that women are more likely to receive BCPR. In other studies, women were found to be less likely to receive BCPR in public but equally or more likely to receive BCPR in residential settings. The general reluctance to perform BCPR on women in the Western countries was attributed to perceived frailty of women, chest exposure, pregnancy, gender stereotypes, oversexualization of women's bodies, and belief that women are unlikely to experience a cardiac arrest. Most studies worldwide indicated that women were less likely to receive BCPR than men. Further research from non-Western countries is needed to understand the impact of cultural and socioeconomic settings on such biases and design customized interventions accordingly.

Factors predicting the return of spontaneous circulation rate of cardiopulmonary resuscitation in China: Development and evaluation of predictive nomogram

Background

This study aimed to construct and internally validate a probability of the return of spontaneous circulation (ROSC) rate nomogram in a Chinese population of patients with cardiac arrest (CA).

Methods

Patients with CA receiving standard cardiopulmonary resuscitation (CPR) were studied retrospectively. The minor absolute shrinkage and selection operator (LASSO) regression analysis and multivariable logistic regression evaluated various demographic and clinicopathological characteristics. A predictive nomogram was constructed and evaluated for accuracy and reliability using C-index, the area under the receiver operating characteristic curve (AUC), calibration plot, and decision curve analysis (DCA).

Results

A cohort of 508 patients who had experienced CA and received standard CPR was randomly divided into training (70 %, n = 356) and validation groups (30 %, n = 152) for the study. LASSO regression analysis and multivariable logistic regression revealed that thirteen variables, such as age, CPR start time, Electric defibrillation, Epinephrine, Sodium bicarbonate (NaHCO3), CPR Compression duration, The postoperative prothrombin (PT) time, Lactate (Lac), Cardiac troponin (cTn), Potassium (K+), D-dimer, Hypertension (HBP), and Diabetes mellitus (DM), were found to be independent predictors of the ROSC rate of CPR. The nomogram model showed exceptional discrimination, with a C-index of 0.933 (95 % confidence interval: 0.882-0.984). Even in the internal validation, a remarkable C-index value of 0.926 (95 % confidence interval: 0.875-0.977) was still obtained. The accuracy and reliability of the model were also verified by the AUC of 0.923 in the training group and 0.926 in the validation group. The calibration curve showed the model agreed with the actual results. DCA suggested that the predictive nomogram had clinical utility.

Conclusions

A predictive nomogram model was successfully established and proved to identify the influencing factors of the ROSC rate in patients with CA. During cardiopulmonary resuscitation, adjusting the emergency treatment based on the influence factors on ROSC rate is suggested to improve the treatment rate of patients with CA.

Urban drone stations siting optimization based on hybrid algorithm of MILP and machine learning

Urban environments, characterized by high population density and intricate infrastructures, are susceptible to a range of emergencies such as fires and traffic accidents. Optimal placement and distribution of fire stations and ambulance centers are thus imperative for safeguarding both life and property. An investigation into the distribution inefficiencies of emergency service facilities in selected districts of Chengdu reveals that imbalanced distribution of these facilities results in suboptimal response times during critical incidents. To address this challenge, a two-stage clustering method, incorporating X-means and K-means algorithms, is employed to identify optimal number and locations for Unmanned Aerial Vehicle (UAV) fire stations and drone ambulance centers. A Mixed-Integer Linear Programming (MILP) model is subsequently constructed and solved using the Gurobi optimization platform. Bayesian optimization-a machine learning technique-is exploited to elucidate the interplay between response speed and service capacity of these UAV-based emergency service stations under an optimized layout. Results affirm that integration of MILP and machine learning provides a robust framework for solving complex problems related to the siting and allocation of emergency service facilities. The proposed hybrid algorithm demonstrates substantial potential for enhancing emergency preparedness and response in urban settings.

Extracorporeal vs. conventional CPR for out-of-hospital cardiac arrest: A systematic review and meta-analysis

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) remains a significant cause of mortality and morbidity worldwide. Extracorporeal cardiopulmonary resuscitation (ECPR) is a potential intervention for OHCA, but its effectiveness compared to conventional cardiopulmonary resuscitation (CCPR) needs further evaluation.

METHOD

We systematically searched PubMed, Embase, the Cochrane Library, Web of Science, and ClinicalTrials.gov for relevant studies from January 2010 to March 2023. Pooled meta-analysis was performed to investigate any potential association between ECPR and improved survival and neurological outcomes.

RESULTS

This systematic review and meta-analysis included two randomized controlled trials enrolling 162 participants and 10 observational cohort studies enrolling 4507 participants. The pooled meta-analysis demonstrated that compared to CCRP, ECPR did not improve survival and neurological outcomes at 180 days following OHCA (RR: 3.39, 95% CI: 0.79 to 14.64; RR: 2.35, 95% CI: 0.97 to 5.67). While a beneficial effect of ECPR was obtained regarding 30-day survival and neurological outcomes. Furthermore, ECPR was associated with a higher risk of bleeding complications. Subgroup analysis showed that ECPR was prominently beneficial when exclusively initiated in the emergency department. Additional post-resuscitation treatments did not significantly impact the efficacy of ECPR on 180-day survival with favorable neurological outcomes.

CONCLUSIONS

There is no high-quality evidence supporting the superiority of ECPR over CCPR in terms of survival and neurological outcomes in OHCA patients. However, due to the potential for bias, heterogeneity among studies, and inconsistency in practice, the non-significant results do not preclude the potential benefits of ECPR. Further high-quality research is warranted to optimize ECPR practice and provide more generalizable evidence. Clinical trial registration PROSPERO, https://www.crd.york.ac.uk/prospero/, registry number: CRD42023402211.

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.

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.

Comparison of smokers' mortality with non-smokers following out-of-hospital cardiac arrests: a systematic review and meta-analysis

OBJECTIVE

Although some studies have linked smoking to mortality after out-of-hospital cardiac arrests (OHCAs), data regarding smoking and mortality after OHCAs have not yet been discussed in a meta-analysis. Thus, this study conducted this systematic review to clarify the association.

METHODS

The study searched Medline-PubMed, Web of Science, Embase and Cochrane libraries between January 1972 and July 2022 for studies that evaluated the association between smoking and mortality after OHCAs. Studies that reportedly showed relative risk estimates with 95% confidence intervals (CIs) were included.

RESULTS

Incorporating a collective of five studies comprising 2477 participants, the analysis revealed a lower mortality risk among smokers in the aftermath of OHCAs compared with non-smokers (odds ratio: 0.77; 95% CI 0.61-0.96; P < 0.05). Egger's test showed no publication bias in the relationship between smoking and mortality after OHCAs.

CONCLUSIONS

After experiencing OHCAs, smokers had lower mortality than non-smokers. However, due to the lack of data, this 'smoker's paradox' still needs other covariate effects and further studies to be considered valid.

Incidence, process of care, and outcomes of out-of-hospital cardiac arrest in China: a prospective study of the BASIC-OHCA registry

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) is an important global public health issue, but its epidemiology and outcomes in low-income and middle-income countries remain largely unknown. We aim to comprehensively describe the incidence, process of care, and outcomes of OHCA in China.

METHODS

In the prospective, multicentre, population-based Baseline Investigation of Out-of-hospital Cardiac Arrest (BASIC-OHCA) registry study, participating sites were selected from both urban and rural areas in all seven geographical regions across China. All patients with OHCA assessed by emergency medical service (EMS) staff were consecutively enrolled from Aug 1, 2019, to Dec 31, 2020. Patients with suspected cardiac arrest assessed by bystanders whose return of spontaneous circulation was achieved without the need for defibrillation or EMS personnel cardiopulmonary resuscitation were excluded. Patients with all key variables missing were excluded, including resuscitation attempt, age, sex, witnessed status, cause, all process of care indicators, and all outcome measures. In this analysis, we included data for EMS agencies serving 25 monitoring sites (20 urban and five rural) that included the entire serving population, data for the whole of 2020, and at least 50 OHCA patients in 2020. Data were collected and reported using the Utstein template. We calculated the crude incidence of EMS-assessed OHCA in 2020. We also report data on baseline characteristics (including sex, cause, location of OHCA, and presence of shockable rhythm), process of care (including EMS response time, cardiopulmonary resuscitation, defibrillation, and advanced life support), and outcomes of non-traumatic OHCA between Aug 1, 2019, and Dec 31, 2020, including survival and survival with favourable neurological outcomes at discharge or 30 days, and at 6 and 12 months.

FINDINGS

Of 115·1 million people served by the 25 participating sites, 132 262 EMS-assessed patients with OHCA were enrolled, and resuscitation was attempted for 42 054 (31·8%) patients between Aug 1, 2019, and Dec 31, 2020. The crude incidence of EMS-assessed OHCA was 95·7 per 100 000 population (95% CI 95·6-95·8) in 2020. Among 38 227 individuals with non-traumatic OHCA, 25 958 (67·9%) were male, 30 282 (79·2%) had a cardiac arrest at home, 32 523 (85·1%) had a presumed cardiac cause, and 2297 (6·0%) presented with an initial shockable rhythm. 4049 (11·5%) of 35 090 patients with an unwitnessed or bystander-witnessed OHCA received dispatcher-assisted cardiopulmonary resuscitation and 7121 (20·3%) received bystander cardiopulmonary resuscitation; only 14 (<0·1%) patients were assessed by bystanders with an automated external defibrillator. The median EMS response time was 12 min (IQR 9-16). At hospital discharge or 30 days, 441 (1·2%) of 38 227 survived, 304 (0·8%) survived up to 6 months, and 269 (0·7%) up to 12 months. At hospital discharge or 30 days, 309 (0·8%) survived with favourable neurological outcomes, 257 (0·7%) had favourable neurological outcomes at 6 months, and 236 (0·6%) at 12 months.

INTERPRETATION

Our findings revealed a high burden of EMS-assessed OHCA with a low proportion of resuscitation attempts. The suboptimal implementation of chain of survival and unsatisfactory prognosis call for national efforts to improve the care and outcomes of patients with OHCA in China.

FUNDING

The National Science & Technology Fundamental Resources Investigation Program of China, the State Key Program of the National Natural Science Foundation of China, Taishan Pandeng Scholar Program of Shandong Province, the Key Research & Development Program of Shandong Province, the Interdisciplinary Young Researcher Groups Program of Shandong University, the Clinical Research Center of Shandong University, the ECCM Program of Clinical Research Center of Shandong University, and the Natural Science Foundation of Shandong Province.

Resuscitation of out-of-hospital cardiac arrest in China: A systematic review and Utstein-style data analysis based on the Chain of Survival

AIM

Out-of-hospital cardiac arrest (OHCA) contributes to substantial mortality, but its resuscitation status in China is unknown. We aimed to describe and analyze out-of-hospital cardiac arrest in terms of Chain of Survival.

METHODS

We systematically collected Utstein-style publications. Scenarios were prespecified, including either emergency medical service (EMS) assessing and attending cardiac arrest, resuscitation attempted by a bystander, resuscitation attempted by EMS, or in-hospital treatment. Random-effect models were used in a meta-analysis to pool rate ratios (RRs) with 95% confidence intervals (CIs) from multiple cohorts.

RESULTS

We analyzed 59 Chains involving 233,376 Chinese patients. The median rate of survival to discharge (interquartile range) was 0.35 % (0.06 %-0.61 %), 3.66 % (3.06 %-3.85 %), 1.23 % (0.57%-1.36%), and 2.73% (2.04%-3.42%) for four scenarios. The rate was significantly higher for bystander resuscitation than for EMS (P = 0.025) or in-hospital treatment (P = 0.301). However, only 4.8 % (1.6 %-8.2 %) of patients received bystander resuscitation, with no bystander defibrillation and a median response time of 9-15 minutes for EMS. Compared with controls without witnesses, arrest being witnessed and with bystander resuscitation increased rates of survival to discharge by 1.97 (I2 = 0, P for I2 = 0.583; pooled RR 2.97; 95% CI 1.47-6.02) and 6.79 (I2 = 0, P for I2 = 0.593; pooled RR 7.79; 95 % CI 3.40-17.84) times, following a markedly increasing trend.

CONCLUSIONS

A low probability of first aid at multiple points is linked to poor survival following OHCA. It is essential to strengthen front links in the Chain of Survival in China, including among witnesses, bystanders, and emergency response.

Development and Validation of Machine Learning-Based Models to Predict In-Hospital Mortality in Life-Threatening Ventricular Arrhythmias: Retrospective Cohort Study

BACKGROUND

Life-threatening ventricular arrhythmias (LTVAs) are main causes of sudden cardiac arrest and are highly associated with an increased risk of mortality. A prediction model that enables early identification of the high-risk individuals is still lacking.

OBJECTIVE

We aimed to build machine learning (ML)-based models to predict in-hospital mortality in patients with LTVA.

METHODS

A total of 3140 patients with LTVA were randomly divided into training (n=2512, 80%) and internal validation (n=628, 20%) sets. Moreover, data of 2851 patients from another database were collected as the external validation set. The primary output was the probability of in-hospital mortality. The discriminatory ability was evaluated by the area under the receiver operating characteristic curve (AUC). The prediction performances of 5 ML algorithms were compared with 2 conventional scoring systems, namely, the simplified acute physiology score (SAPS-II) and the logistic organ dysfunction system (LODS).

RESULTS

The prediction performance of the 5 ML algorithms significantly outperformed the traditional models in predicting in-hospital mortality. CatBoost showed the highest AUC of 90.5% (95% CI 87.5%-93.5%), followed by LightGBM with an AUC of 90.1% (95% CI 86.8%-93.4%). Conversely, the predictive values of SAPS-II and LODS were unsatisfactory, with AUCs of 78.0% (95% CI 71.7%-84.3%) and 74.9% (95% CI 67.2%-82.6%), respectively. The superiority of ML-based models was also shown in the external validation set.

CONCLUSIONS

ML-based models could improve the predictive values of in-hospital mortality prediction for patients with LTVA compared with traditional scoring systems.

Flufenamic acid improves survival and neurologic outcome after successful cardiopulmonary resuscitation in mice

Background

Brain injury is the main cause of high mortality and disability after successful cardiopulmonary resuscitation (CPR) from sudden cardiac arrest (CA). The transient receptor potential M4 (TRPM4) channel is a novel target for ameliorating blood–brain barrier (BBB) disruption and neuroinflammation. Herein, we tested whether flufenamic acid (FFA), which is reported to block TRPM4 with high potency, could confer neuroprotection against brain injury secondary to CA/CPR and whether its action was exerted by blocking the TRPM4 channel.

Methods

Wild-type (WT) and Trpm4 knockout (Trpm4^−/−) mice subjected to 10-min CA/CPR were randomized to receive FFA or vehicle once daily. Post-CA/CPR brain injuries including neurologic deficits, survival rate, histological damage, edema formation, BBB destabilization and neuroinflammation were assessed.

Results

In WT mice subjected to CA/CPR, FFA was effective in improving survival and neurologic outcome, reducing neuropathological injuries, attenuating brain edema, lessening the leakage of IgG and Evans blue dye, restoring tight junction protein expression and promoting microglia/macrophages from the pro-inflammatory subtype toward the anti-inflammatory subtype. In comparison to WT mice, Trpm4^−/− mice exhibited less neurologic deficiency, milder histological impairment, more BBB integrity and more anti-inflammatory microglia/macrophage polarization. As expected, FFA did not provide a benefit of superposition compared with vehicle in the Trpm4^−/− mice after CA/CPR.

Conclusions

FFA mitigates BBB breach and modifies the functional status of microglia/macrophages, thereby improving survival and neurologic deficits following CA/CPR. The neuroprotective effects occur at least partially by interfering with the TRPM4 channel in the neurovascular unit. These results indicate the significant clinical potential of FFA to improve the prognosis for CA victims who are successfully resuscitated.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02571-2.

Mild Hypothermia Alleviates Complement C5a-Induced Neuronal Autophagy During Brain Ischemia-Reperfusion Injury After Cardiac Arrest

After restoration of spontaneous circulation (ROSC) following cardiac arrest, complements can be activated and excessive autophagy can contribute to the brain ischemia-reperfusion (I/R) injury. Mild hypothermia (HT) protects against brain I/R injury after ROSC, but the mechanisms have not been fully elucidated. Here, we found that HT significantly inhibited the increases in serum NSE, S100β, and C5a, as well as neurologic deficit scores, TUNEL-positive cells, and autophagic vacuoles in the pig brain cortex after ROSC. The C5a receptor 1 (C5aR1) mRNA and the C5a, C5aR1, Beclin 1, LC3-II, and cleaved caspase-3 proteins were significantly increased, but the P62 protein and the PI3K/Akt/mTOR pathway-related proteins were significantly reduced in pigs after ROSC or neuronal oxygen-glucose deprivation/reoxygenation. HT could significantly attenuate the above changes in NT-treated neurons. Furthermore, C5a treatment induced autophagy and apoptosis and reduced the PI3K/Akt/mTOR pathway-related proteins in cultured neurons, which could be reversed by C5aR1 antagonist PMX205. Our findings demonstrated that C5a could bind to C5aR1 to induce neuronal autophagy during the brain I/R injury, which was associated with the inhibited PI3K/Akt/mTOR pathway. HT could inhibit C5a-induced neuronal autophagy by regulating the C5a-C5aR1 interaction and the PI3K/Akt/mTOR pathway, which might be one of the neuroprotective mechanisms underlying I/R injury. The C5a receptor 1 (C5aR1) mRNA and the C5a, C5aR1, Beclin 1, LC3-II, and cleaved caspase-3 proteins were significantly increased, but the P62 protein and the PI3K/Akt/mTOR pathway-related proteins were significantly reduced in pigs after ROSC or neuronal oxygen-glucose deprivation/reoxygenation. Mild hypothermia (HT) could significantly attenuate the above changes in NT-treated neurons. Furthermore, C5a treatment induced autophagy and apoptosis and reduced the PI3K/Akt/mTOR pathway-related proteins in cultured neurons, which could be reversed by C5aR1 antagonist PMX205. Proposed mechanism by which HT protects against brain I/R injury by repressing C5a-C5aR1-induced excessive autophagy. Complement activation in response to brain I/R injury generates C5a that can interact with C5aR1 to inactivate mTOR, probably through the PI3K-AKT pathway, which can finally lead to autophagy activation. The excessively activated autophagy ultimately contributes to cell apoptosis and brain injury. HT may alleviate complement activation and then reduce C5a-induced autophagy to protect against brain I/R injury. HT, mild hypothermia; I/R, ischemia reperfusion.

Chrysophanol postconditioning attenuated cerebral ischemia-reperfusion injury induced NLRP3-related pyroptosis in a TRAF6-dependent manner

Individuals who suffer from post-CA (cardiac arrest) brain injury experience higher mortality and more severe functional disability. Neuroinflammation has been identified as a vital factor in cerebral ischemia-reperfusion injury (CIRI) following CA. Pyroptosis induces neuronal death by triggering an excessive inflammatory injury. Chrysophanol possesses robust anti-inflammatory features, and it is protective against CIRI. The purpose of this research was to assess the effect of Chrysophanol postconditioning on CIRI-induced pyroptotic cell death, and to explore its underlying mechanisms. CIRI was induced in rats by CA and subsequent cardiopulmonary resuscitation, and PC12 cells were exposed to oxygen-glucose deprivation/reoxygenation (OGD/R) to imitate CIRI in vitro. It was found that post-CA brain injury led to a notable cerebral damage revealed by histopathological changes and neurological outcomes. The existence of pyroptosis was also confirmed in in vivo and in vitro CIRI models. Moreover, we further confirmed that Chrysophanol, the main bioactive ingredient of Rhubarb, significantly suppressed expressions of pyroptosis-associated proteins, e.g., NLRP3, ASC, cleaved-caspase-1 and N-terminal GSDMD, and inhibited the expression of tumor necrosis factor receptor-associated factor 6 (TRAF6). Furthermore, NLRP3 overexpression neutralized the neuroprotection of Chrysophanol postconditioning, suggesting that pyroptosis was the major neuronal death pathway modulated by Chrysophanol postconditioning in OGD/R. Additionally, the neuroprotection of Chrysophanol postconditioning was also abolished by gain-of-function analyses of TRAF6. Finally, the results demonstrated that Chrysophanol postconditioning suppressed the interaction between TRAF6 and NLRP3. Taken together, our findings revealed that Chrysophanol postconditioning was protective against CIRI by inhibiting NLRP3-related pyroptosis in a TRAF6-dependent manner.

Urinary Proteome Analysis of Global Cerebral Ischemia-Reperfusion Injury Rat Model via Data-Independent Acquisition and Parallel Reaction Monitoring Proteomics

Cerebral ischemia–reperfusion (I/R) injury is the leading cause of death in severe hypotension caused by cardiac arrest, drowning, and excessive blood loss. Urine can sensitively reflect pathophysiological changes in the brain even at an early stage. In this study, a rat model of global cerebral I/R injury was established via Pulsinelli’s four-vessel occlusion (4-VO) method. Overall, 164 urinary proteins significantly changed in the 4-VO rat urine samples compared to the control samples by data-independent acquisition (DIA) proteomics technique (1.5-fold change, p < 0.05). Gene Ontology annotation showed that the acute-phase response, the ERK1 and ERK2 cascade, endopeptidase activity, blood coagulation, and angiogenesis were overrepresented. After parallel reaction monitoring (PRM) validation, 15 differential proteins having human orthologs were verified as the potential urinary markers associated with cerebral I/R injury. Of these potential biomarkers, 8 proteins were reported to be closely associated with cerebral I/R injury. Nine differential proteins changed even when there were no clinical manifestations or histopathological cerebral damage, including FGG, COMP, TFF2, HG2A, KNG1, CATZ, PTGDS, PRVA, and HEPC. These 9 proteins are potential biomarkers for early screening of cerebral I/R injury to prevent the development of cerebral injury. KNG1, CATZ, PTGDS, PRVA, and HEPC showed an overall trend of upregulation or downregulation at 12 and 48 h after I/R injury, reflecting the progression of cerebral I/R injury. These 5 proteins may serve as potential biomarkers for prognostic evaluation of cerebral I/R injury. These findings provide important clues to inform the monitoring of cerebral I/R injury and further the current understanding of its molecular biological mechanisms.

Globally, GDP Per Capita Correlates Strongly with Rates of Bystander CPR

Introduction:

Bystander CPR is vital in improving outcomes for out-of-hospital cardiac arrest. There has been ample literature describing disparities in bystander CPR within specific countries, such as the United States, Australia, and the Netherlands. However, there has not been significant literature describing such disparities between countries.

Methods:

We examined various studies published between 2000 and 2021 that reported rates of bystander CPR in various countries. These bystander CPR rates were correlated with the GDP per capita of that country during the time the study was conducted. The correlation between GDP per capita and rates of bystander CPR was assessed.

Results:

A total of 29 studies in 35 communities across 25 countries were examined. Reported rates of bystander CPR ranged from 1.3% to 72%. From this, a strong and significant correlation between GDP per capita and rates of bystander CPR was apparent; 0.772 (p < .01), r² = 0.596.

Conclusions:

GDP per capita can be thought of as a composite endpoint that takes into account various aspects of a country’s social and economic well-being. Socioeconomically-advantaged communities likely have a better ability to provide CPR education to community members, and our findings mirror localized analyses comparing socioeconomic status and rates of bystander CPR. Future studies should continue to elucidate transnational disparities in cardiac arrest, and efforts should be directed at providing CPR education to communities with low rates of bystander CPR; low-and-middle-income countries may represent attractive targets for such interventions. However, it may be possible that rates of bystander CPR may not improve unless significant upstream improvements to socioeconomic factors take place.

Clinicopathological correlates of out-of-hospital cardiac arrests

Background

Sudden cardiac arrest with or without sudden cardiac death (SCD) represents a heterogeneous spectrum of underlying etiology but is often a catastrophic event. Despite improvements in pre-hospital response and post-resuscitation care, outcomes remain grim. Thus, we aim to evaluate the predictors of survival in out-of-hospital cardiac arrests (OHCAs) and describe autopsy findings of those with the uncertain cause of death (COD).

Methods

This is a subgroup analysis of the Singapore cohort from the Pan Asian Resuscitation Outcome Study which studied 933 OHCAs admitted to two Singapore tertiary hospitals from April 2010 to May 2012.

Results

Of the patients analysed, 30.2% (n = 282) had an initial return of spontaneous circulation (ROSC) at the emergency department, 18.0% (n = 168) had sustained ROSC with subsequent admission and 3.4% (n = 32) had survival to discharge. On multivariate analysis, an initial shockable rhythm, a witnessed event, prehospital defibrillation, and shorter time to hospital predicted ROSC as well as survival to discharge. A total of 163 (17.5%) autopsies were performed of which a cardiac etiology of SCD was noted in 92.1% (n = 151). Ischemic heart disease accounted for 54.3% (n = 89) of the autopsy cohort, with acute myocardial infarction (26.9%, n = 44) and myocarditis (3.7%, n = 6) rounding out the top three causes of demise.

Conclusion

OHCA remains a clinical presentation that portends a poor prognosis. Of those with uncertain COD, cardiac etiology appears to predominate from autopsy study. Identification of prognostic factors will play an important role in improving individual-level and systemic-level variables to further optimize outcomes.

Public knowledge and attitudes toward automated external defibrillators use among first aid eLearning course participants: a survey

Objective

Survival from out-of-hospital cardiac arrest (OHCA) often depends on the effective and immediate use of automated external defibrillators (AEDs). Given that there have been few studies about AED use in China, the purpose of this study is to investigate the knowledge and attitudes regarding AED use among the Chinese public, then provide an effective suggestion for AED education strategies and legislation.

Method

The online survey was conducted among Chinese participants of the First Aid eLearning courses in June 2020.

Result

A total of 2565 (95.00%) surveys were completed, only 23.46% of respondents with non-medical related respondents reported having attended previous AED training courses. Regarding the basic knowledge of AEDs, few respondents (12.28%, n = 315) could answer all four questions correctly. 95.67% (n = 2454) were willing to learn AED use. Even if without the precondition of being skilled in AEDs, the female was more likely to rescue OHCA patients than the male (p = 0.003). Almost all respondents (96.65%) showed a strong willingness to rescue OHCA patients with training in using AEDs. The top four barriers to rescuing OHCA patients were lack of practical performing ability (60.47%), fear of hurting patients (59.30%), inadequate knowledge of resuscitation techniques (44.19%), and worry about taking legal responsibility (26.74%).

Conclusion

Our study reflects a deficiency of AED knowledge among the general public in China. However, positive attitudes towards rescuing OHCA patients and learning AED use were observed, which indicates that measures need to be taken to disseminate knowledge and use of AEDs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-022-01863-1.

Hydrogen therapy after resuscitation improves myocardial injury involving inhibition of autophagy in an asphyxial rat model of cardiac arrest

Hydrogen (H₂) therapy is a therapeutic strategy using molecular H₂. Due to its ability to regulate cell homeostasis, H₂ therapy has exhibited marked therapeutic effects on a number of oxidative stress-associated diseases. The present study investigated the effectiveness of H₂ therapy in protecting against myocardial injury in a rat model of asphyxial cardiac arrest and cardiopulmonary resuscitation. Rats underwent 10-min asphyxia-induced cardiac arrest (CA) and cardiopulmonary resuscitation (CPR), and were randomly divided into control and H₂ therapy groups. After resuscitation, the H₂ therapy group was administered room air mixed with 2% H₂ gas for respiration. During CA/CPR, the arterial pressure and heart rate were measured every minute. Survival rate, cardiac function, myocardial injury biomarkers creatine kinase-MB and cardiac troponin-T, and histopathological changes were evaluated to determine the protective effects of H₂ therapy in CA/CPR. Immunohistochemistry and western blot analysis were used to determine the expression levels of autophagy-associated proteins. In vitro, H9C2 cells were subjected to hypoxia/reoxygenation and H₂-rich medium was used in H₂ treatment groups. Western blotting and immunofluorescence were used to observe the expression levels of autophagy-associated proteins. Moreover, an adenovirus-monomeric red fluorescent protein-green fluorescent protein-LC3 construct was used to explore the dynamics of autophagy in the H9C2 cells. The results showed that H₂ therapy significantly improved post-resuscitation survival and cardiac function. H₂ therapy also improved mitochondrial mass and decreased autophagosome numbers in cardiomyocytes after resuscitation. The treatment inhibited autophagy activation, with lower expression levels of autophagy-associated proteins and decreased autophagosome formation in vivo and vitro. In conclusion, H₂ gas inhalation after return of spontaneous circulation improved cardiac function via the inhibition of autophagy.

Trends and associated factors in place of death among individuals with cardiovascular disease in China, 2008-2020: A population-based study

Background

Cardiovascular disease (CVD) is the leading cause of death (COD) in China. Understanding the characteristics of place of death (POD) among CVD deaths would be of great importance to evaluate the healthcare service utilization at the end stage of life. Limited studies have reported the POD distribution among CVD deaths, and little was known about the associated factors of hospital CVD deaths.

Methods

By using data from National Mortality Surveillance System (NMSS) in China, this study presented the characteristics of POD distribution during 2008 and 2020. Afterwards, multilevel logistic regression was used to explore associated factors of hospital CVD deaths and quantify the magnitude to which the spatial variations of hospital CVD deaths could be explained by those associated factors.

Findings

During 2008-2020, there was 7101871 CVD deaths collected by NMSS in China, with 77·13% home deaths and 18·49% hospital deaths. Shanghai (59·40%) had the highest percentage of hospital CVD deaths. Age, sex, ethnicity, marital status, education, occupation, underlying COD were significant influential factors of hospital CVD deaths. Spatial variations were shown at provincial level, with 33·88% of them being explained by factors at individual level.

Interpretation

Home was the leading POD among CVD deaths in China, those CVD decedents characterized as the female, the youngest, Han population, the married, the retiree, lived in urban areas, with higher socioeconomic status and died of chronic CVDs had a higher probability of hospital deaths. Providing accessible and available healthcare services were priorities to improve quality of end-of-life care, significant variations among provinces and sub-population also reminded us of the requirements for equal healthcare resources allocation and multiple options for minorities of POD preference at the end stage of life.

Funding

National Key Research & Development Program of China (grant number 2018YFC1315301)

Monitoring cardiopulmonary resuscitation quality in emergency departments: a national survey in China on current knowledge, attitudes, and practices

BACKGROUND

To investigate current knowledge, attitudes, and practices for CPR quality control among emergency physicians in Chinese tertiary hospitals.

METHODS

Anonymous questionnaires were distributed to physicians in 75 tertiary hospitals in China between January and July 2018.

RESULTS

A total of 1405 respondents answered the survey without obvious logical errors. Only 54.4% respondents knew all criteria of high-quality CPR. A total of 91.0% of respondents considered CPR quality monitoring should be used, 72.4% knew the objective method for monitoring, and 63.2% always/often monitored CPR quality during actual resuscitation. The main problems during CPR were related to chest compression: low quality due to fatigue (67.3%), inappropriate depth (57.3%) and rate (54.1%). The use of recommended monitoring methods was reported as follows, ETCO2 was 42.7%, audio-visual feedback devices was 10.1%, coronary perfusion pressure was 17.9%, and invasive arterial pressure was 31.1%. A total of 96.3% of respondents considered it necessary to participate in regular CPR retraining, but 21.4% did not receive any retraining. The ideal retraining interval was considered to be 3 to 6 months, but the actual interval was 6 to 12 months. Only 49.7% of respondents reported that feedback devices were always/often used in CPR training.

CONCLUSION

Chinese emergency physicians were very concerned about CPR quality, but they did not fully understand the high-quality criteria and their impact on prognosis. CPR quality monitoring was not a routine procedure during actual resuscitation. The methods recommended in guidelines were rarely used in practice. Many physicians had not received retraining or received retraining at long intervals. Feedback devices were not commonly used in CPR training.

National survey of do not attempt resuscitation decisions on out-of-hospital cardiac arrest in China

BACKGROUND

To investigate and understand the determinants of decisions not to attempt resuscitation following out-of-hospital cardiac arrest, to contribute to establishing rules that are appropriate to China.

METHODS

We recruited participants through directors of emergency medical services across China. A 28-question web survey was available between February 5 and March 6, 2021 that targeted demographic information and views on emergency work and cardiopulmonary resuscitation. Each question was assigned a value between 1 and 7 based on the level of importance from low to high. T-tests, one-way analysis of variance, and Kruskal-Wallis H-tests were used to compare continuous variables. Binary logistic regression analysis was used to identify factors influencing when people considered it suitable to initiate cardiopulmonary resuscitation.

RESULTS

The study involved 4289 participants from 31 provinces, autonomous regions and municipalities in mainland China, of whom 52.8% were male. The top three reasons for not attempting cardiopulmonary resuscitation were decomposition/hypostasis/rigor mortis (6.39 ± 1.44 points), massive injury (4.57 ± 2.08 points) and family members' preference (4.35 ± 1.98 points). In total, 2761 (64.4%) thought emergency services should not attempt cardiopulmonary resuscitation when cardiac arrest had happened more than 30 min before, and there had been no bystander cardiopulmonary resuscitation. Gender (OR 1.233, p = 0.002), religion (OR 1.147, p = 0.046), level (OR 0.903, p = 0.028) or classification of city (OR 0.920, p = 0.049), years of work experience (OR 0.884, p = 0.004), and major (OR 1.032, p = 0.044) all influenced how long after cardiac arrest was considered suitable for initiating cardiopulmonary resuscitation.

CONCLUSIONS

Chinese emergency physicians have different perceptions of when not to attempt resuscitation to those practicing elsewhere. The existing guidelines for resuscitation are not suitable for China, and China-specific guidelines need to be established.

Optimization of the Pre-Hospital Rescue System for Out-of-Hospital Cardiac Arrest in China

Out-of-hospital cardiac arrest (OHCA) presents a significant public health challenge in China. A sharp contrast in survival rate after OHCA exists between China and more developed countries. Due to the short life-saving time window, emergency medical services (EMS) and bystanders peripheral to EMS are key contributors to survival after OHCA. Here we discuss limitations and challenges for current EMS in rescuing OHCA by reviewing requirements for EMS in China. We call for an updated public health-based pre-hospital rescue system that includes establishing a cardiac arrest registry, promoting a "Three Early's" campaign [early dialing of emergency hotline 120, early cardiopulmonary resuscitation (CPR), and early defibrillation], and operating a mechanism comprised of professional public health institutions (EMS, CDC, specialized disease prevention and control institutions, and health education institutions) as well as many governmental departments, such as healthcare, industry and information technology, and education, and non-governmental organizations, such as the Red Cross Society. Following the optimization of the pre-hospital rescue system and the participation of the whole population in self-rescue and mutual rescue, we believe that a dramatic improvement in OHCA survival will come about in China.

Time trends in cardiovascular disease mortality attributable to non-optimal temperatures in China: An age-period-cohort analysis using the Global Burden of Disease Study 2019

Background

Associations between non-optimal temperatures and cardiovascular disease (CVD) mortality risk have been previously reported, yet the trends of CVD mortality attributable to non-optimal temperatures remain unclear in China. We analyzed trends in CVD mortality attributable to non-optimal temperatures and associations with age, period, and birth cohort.

Methods

Data were obtained from the Global Burden of Disease Study (GBD) 2019. Joinpoint regression analysis was used to calculate annual percent change (APC) and average annual percent change (AAPC) from 1990 to 2019. We used the age-period-cohort model to analyze age, period, and cohort effects in CVD mortality attributable to non-optimal temperatures between 1990 and 2019.

Results

The age-standardized mortality rate (ASMR) of CVD attributable to non-optimal temperature generally declined in China from 1990 to 2019, whereas ischemic heart disease (IHD) increased slightly. Low temperatures have a greater death burden than high temperatures, but the death burden from high temperatures showed steady increases. Joinpoint regression analysis showed that CVD mortality decreased in all age groups except for IHD, and the decreases were greater in females than in males. The mortality of CVD attributable to non-optimal temperatures of males was higher than females. The mortality rate showed an upwards trend with age across all CVD categories. Period risks were generally found in unfavorable trends. The cohort effects showed a progressive downward trend during the entire period.

Conclusion

Although there have been reductions in CVD mortality attributable to non-optimum temperatures, the mortality of IHD has increased and the burden from non-optimal temperatures remains high in China. In the context of global climate change, our results call for more attention and strategies to address climate change that protect human health from non-optimal temperatures.

Trend in survival after out-of-hospital cardiac arrest and its relationship with bystander cardiopulmonary resuscitation: a six-year prospective observational study in Beijing

Background

Out-of-hospital cardiac arrest (OHCA), a global health problem with a survival rate ranging from 2 to 22% across different countries, has been a leading cause of premature death for decades. The aim of this study was to evaluate the trends of survival after OHCA over time and its relationship with bystander cardiopulmonary resuscitation (CPR), initial shockable rhythm, return of spontaneous circulation (ROSC), and survived event.

Methods

In this prospective observational study, data of OHCA patients were collected following the “Utstein style” by the Beijing, China, Emergency Medical Service (EMS) from January 2011 (data from February to June in 2011 was not collected) to October 2016. Patients who had a cardiac arrest and for whom an ambulance was dispatched were included in this study. All cases were followed up to determine hospital discharge or death. The trend of OHCA survival was analyzed using the Chi-square test. The relationship among bystander CPR, initial shockable rhythm, ROSC, survived event, and OHCA survival rate was analyzed using multivariate path analyses with maximum standard likelihood estimation.

Results

A total of 25,421 cases were transferred by the Beijing EMS; among them, 5042 (19.8%) were OHCA (median age: 78 years, interquartile range: 63–85, 60.1% male), and 484 (9.6%) received bystander CPR. The survival rate was 0.6%, which did not improve from 2012 to 2015 (P = 0.569). Overall, bystander CPR was indirectly associated with an 8.0% (β = 0.080, 95% confidence interval [CI] = 0.064–0.095, P = 0.002) increase in survival rate. The indirect effect of bystander CPR on survival rate through survived event was 6.6% (β = 0.066, 95% CI = 0.051–0.081, P = 0.002), which accounted for 82.5% (0.066 of 0.080) of the total indirect effect. With every 1 increase in survived event, the possibility of survival rate will directly increase by 53.5% (β = 0.535, 95% CI = 0.512–0.554, P = 0.003).

Conclusions

The survival rate after OHCA was low in Beijing which has not improved between 2012 and 2015. The effect of bystander CPR on survival rate was mainly mediated by survived event.

Trial registration

Chinese Clinical Trial Registry: ChiCTR-TRC-12002149 (2 May, 2012, retrospectively registered). http://www.chictr.org.cn/showproj.aspx?proj=7400

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02446-z.

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.

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

AIMS

Long term outcomes after out-of-hospital cardiac arrest (OHCA) are not well understood. This study aimed to evaluate the long-term (1-year and beyond) survival outcomes, including overall survival and survival with favorable neurological status and the quality-of-life (QOL) outcomes, among patients who survived the initial OHCA event (30 days or till hospital discharge).

METHODS

Embase, Medline and PubMed were searched for primary studies (randomized controlled trials, cohort and cross-sectional studies) which reported the long-term survival outcomes of OHCA patients. Data abstraction and quality assessment was conducted, and survival at predetermined timepoints were assessed via single-arm meta-analyses of proportions, using generalized linear mixed models. Comparative meta-analyses were conducted using the Mantel-Haenszel Risk Ratio (RR) estimates, using the DerSimonian and Laird model.

RESULTS

67 studies were included, and among patients that survived to hospital discharge or 30-days, 77.3% (CI=71.2-82.4), 69.6% (CI=54.5-70.3), 62.7% (CI=54.5-70.3), 46.5% (CI=32.0-61.6), and 20.8% (CI=7.8-44.9) survived to 1-, 3-, 5-, 10- and 15-years respectively. Compared to Asia, the probability of 1-year survival was greater in Europe (RR=2.1, CI=1.8-2.3), North America (RR=2.0, CI=1.7-2.2) and Oceania (RR=1.9,CI=1.6-2.1). Males had a higher 1-year survival (RR:1.41, CI=1.25-1.59), and patients with initial shockable rhythm had improved 1-year (RR=3.07, CI=1.78-5.30) and 3-year survival (RR=1.45, CI=1.19-1.77). OHCA occurring in residential locations had worse 1-year survival (RR=0.42, CI=0.25-0.73).

CONCLUSION

Our study found that up to 20.8% of OHCA patients survived to 15-years, and survival was lower in Asia compared to the other regions. Further analysis on the differences in survival between the regions are needed to direct future long-term treatment of OHCA patients.

Different Resting Methods in Improving Laypersons Hands-Only Cardiopulmonary Resuscitation Quality and Reducing Fatigue: A Randomized Crossover Study

Objective

To determine the effects of different resting methods with various rest-start points or rest-compression ratios on improving cardiopulmonary resuscitation (CPR) quality and reducing fatigue during continuous chest compressions (CCC) in 10-min hands-only CPR scenario.

Methods

This prospective crossover study was conducted in 30 laypersons aged 18-65. Trained participants were randomized to follow different orders to perform following hands-only CPR methods: (1) CCC, 10-min CCC; (2) 4+6, 4-min CCC + 6-min of 10-s pause after 60-s compressions; (3) 2+8 (10/60), 2-min CCC + 8-min of 10-s pause after 60-s compressions; (4) 5/30, 2-min CCC + 8-min of 5-s pause after 30-s compressions; (5) 3/15, 2-min CCC + 8-min of 3-s pause after 15-s compressions. CPR quality (depth, rate, hands-off duration, chest compression fraction (CCF)) and participants’ fatigue indicators (heart rate, blood pressure, rating of perceived exertion (RPE)) were compared among methods of different rest-start points and different rest-compression ratios with CCC.

Results

Twenty-eight participants completed all methods. All resting methods reduced the trend of declining compression depth and the trend of increasing RPE while maintaining CCF of more than 86%. In methods with different rest-start points, the 2+8 method showed no difference in overall CPR quality or fatigue, but better CPR quality of every minute than 4+6 method. In methods with different rest-compression ratios, the 3/15 method showed the best CPR quality and the highest heart rate increment.

Conclusion

During prolonged hands-only CPR, appropriate transient rests were associated with higher CPR quality and lower subjectively perceived fatigue in laypersons.

Association of a simple SACAF score with bystander witnessed sudden death due to ventricular tachyarrhythmias in a multicenter cohort

Out-of-hospital cardiac arrest (OHCA) remains a major threat to public health worldwide. OHCA patients presenting initial shockable ventricular tachycardia/ventricular fibrillation (VT/VF) rhythm have a better survival rate. We sought to develop a simple SACAF score to discriminate VT/VF from non-VT/VF OHCAs based on the Taiwan multicenter hospital-based registry database. We analyzed the in- and pre-hospital data, including demographics, baseline comorbidities, response times, automated external defibrillator information, and the 12-lead ECG recording closest to the OHCA event in bystander-witnessed OHCA patients. Among the 461 study patients, male sex (OR 2.54, 95% CI = 1.32–4.88, P = 0.005), age ≤ 65 years (OR 2.78, 95% CI = 1.64–4.70, P < 0.001), cardiovascular diseases (OR 2.97, 95% CI = 1.73–5.11, P < 0.001), and atrial fibrillation (AF) (OR 2.36, 95% CI = 1.17–4.76, P = 0.017) were independent risk factors for VT/VF OHCA (n = 81) compared with non-VT/VF OHCA (n = 380). A composite SACAF score was developed (male Sex, Age ≤ 65 years, Cardiovascular diseases, and AF) and compared with the performance of a modified CHA₂DS₂-VASc score (Cardiovascular diseases, Hypertension, Age ≥ 75 years, Diabetes, previous Stroke, Vascular disease, Age 65–74 years, female Sex category). The area under the receiver operating characteristic curve (AUC) of the SACAF was 0.739 (95% CI = 0.681–0.797, P < 0.001), whereas the AUC of the modified CHA₂DS₂-VASc was 0.474 (95% CI = 0.408–0.541, P = 0.464). A SACAF score of ≥ 2 was useful in discriminating VT/VF from non-VT/VF OHCAs with a sensitivity of 0.75 and a specificity of 0.60. In conclusion, the simple SACAF score appears to be useful in discriminating VT/VF from non-VT/VF bystander-witnessed OHCAs and the findings may also shed light on future mechanistic evaluation.

Mortality and years of life lost of cardiovascular diseases in China, 2005-2020: Empirical evidence from national mortality surveillance system

OBJECTIVES

Cardiovascular disease (CVD) is leading cause of death in China. We aimed to provide national and subnational estimates and its change of premature mortality burden of CVD during 2005-2020.

METHODS

Data from multi-source on the basis of national mortality surveillance system (NMSS) was used to estimate mortality and years of life lost (YLL) of total CVD and its subcategories in Chinese population across 31 provinces during 2005-2020.

RESULTS

Estimated CVD deaths increased from 3.09 million in 2005 to 4.58 million in 2020; the age-standardized mortality rate (ASMR) decreased from 286.85 per 100,000 in 2005 to 245.39 per 100,000 in 2020. A substantial reduction of 19.27% of CVD premature mortality burden, as measured by age-standardized YLL rate, was observed. Ischemic heart disease (IHD), hemorrhagic stroke (HS) and ischemic stroke (IS) were leading 3 causes of CVD death. Marked differences were observed in geographical patterns for total CVD and its subcategories, and it appeared to be lower in areas with higher economic development. Population ageing was dominant driver contributed to CVD deaths increase, followed by population growth. And, age-specific mortality shifts contributed largely to CVD deaths decline in most provinces.

CONCLUSION

Substantial discrepancies were demonstrated in CVD premature mortality burden across China. Targeted considerations were needed to integrate primary care with clinical care through intensifying further strategies for reducing CVD mortality among specific subcategories, high risk population and regions with inadequate healthcare resources.

Angiotensin (1-7) Alleviates Postresuscitation Myocardial Dysfunction by Suppressing Oxidative Stress Through the Phosphoinositide 3-Kinase, Protein Kinase B, and Endothelial Nitric Oxide Synthase Signaling Pathway

ABSTRACT

There is increasing evidence that angiotensin (1-7) [Ang (1-7)] is an endogenous biologically active component of the renin-angiotensin system. However, the role of the Ang (1-7)-MasR axis in postresuscitation myocardial dysfunction (PRMD) and its associated mechanism are still unclear. In this study, we investigated the effect of the Ang (1-7)-MasR axis on myocardial injury after cardiac arrest-cardiopulmonary resuscitation-restoration of spontaneous circulation. We established a model of oxygen/glucose deprivation-reperfusion in myocardial cells in vitro and a rat model of cardiac arrest-cardiopulmonary resuscitation-restoration of spontaneous circulation in vivo. The cell apoptosis rate and the expression of the superoxide anion 3-nitrotyrosine were decreased in the Ang (1-7) group in vitro and in vivo. The mean arterial pressure was decreased, whereas +LVdp/dtmax and -LVdp/dtmax were increased in rats in the Ang (1-7) group. The mRNA and protein levels of Ang II type 1 receptor, MasR, phosphoinositide 3-kinase, protein kinase B, and endothelial nitric oxide synthase were increased in the Ang (1-7) group in vivo. These results indicate that the Ang (1-7)-MasR axis can alleviate PRMD by reducing myocardial tissue damage and oxidative stress through activation of the phosphoinositide 3-kinase-protein kinase B-endothelial nitric oxide synthase signaling pathway and provide a new direction for the clinical treatment of PRMD.

Outcomes of out-of-hospital cardiac arrest in Beijing: a 5-year cross-sectional study

OBJECTIVE

The purpose of this study was to assess the trends in outcomes of out-of-hospital cardiac arrest (OHCA) in Beijing over 5 years.

DESIGN

Cross-sectional study.

METHODS

Adult patients with OHCA of all aetiologies who were treated by the Beijing emergency medical service (EMS) between January 2013 and December 2017 were analysed. Data were collected using the Utstein Style. Cases were followed up for 1 year. Descriptive statistics were used to characterise the sample and logistic regression was performed.

RESULTS

Overall, 5016 patients with OHCA underwent attempted resuscitation by the EMS in urban areas of Beijing during the study period. Survival to hospital discharge was 1.2% in 2013 and 1.6% in 2017 (adjusted rate ratio=1.0, p for trend=0.60). Survival to admission and neurological outcome at discharge did not significantly improve from 2013 to 2017. Patient characteristics and the aetiology and location of cardiac arrest were consistent, but there was a decrease in the initial shockable rhythm (from 6.5% to 5.6%) over the 5 years. The rate of bystander cardiopulmonary resuscitation (CPR) increased steadily over the years (from 10.4% to 19.4%).

CONCLUSION

Survival after OHCA in urban areas of Beijing did not improve significantly over 5 years, with long-term survival being unchanged, although the rate of bystander CPR increased steadily, which enhanced the outcomes of patients who underwent bystander CPR.

Prevention and Control of Cardiac Arrest in Healthy China

Cardiac arrest (CA) usually occurs out of hospitals, comprising approximately 50% of all cardiovascular deaths, which may delay achievement for Healthy China 2030 goals for life expectancy and premature death from major chronic diseases. In this review of Chinese law and health policy, challenges and opportunities are explored for CA prevention and control. A considerable gap would remain even if the CA target in Healthy China 2030 are to be achieved on schedule. Therefore, CA should be included in the national disease prevention and control system and national projects, such as the Healthy Cities Initiative and the Primary Public Health Services to accelerate population-wide Cardiopulmonary Resuscitation training and Automatic External Defibrillation availability. Principles of CA prevention and control should be integrated into all relevant policies.

Awareness, knowledge and attitudes towards cardiopulmonary resuscitation among people with and without heart disease relatives in South China: a cross-sectional survey

OBJECTIVES

To assess the awareness, knowledge and attitudes towards cardiopulmonary resuscitation (CPR) among relatives of people with and without heart disease and their influence in South China.

DESIGN

This is a cross-sectional survey. Logistic regression was used to evaluate the demographic factors associated with CPR training, learning and knowledge.

SETTING

The study was conducted in two hospitals, the largest cardiovascular institute and the largest eye care centre in South China.

PARTICIPANTS

Healthy individuals who accompanied their relatives with heart disease to the outpatient department of cardiovascular disease and systemically healthy patients who came for regular ophthalmic examination and had no relatives with heart disease were consecutively recruited for the study. A total of 1644 respondents with heart disease relatives and 813 respondents without heart disease relatives completed the survey.

RESULTS

Thirty three per cent of respondents never heard of CPR and only 11% had received CPR training. Factors associated with a higher rate of CPR training were higher level of education and income (p<0.001). Most respondents stated that CPR training was necessary and would like to learn CPR. However, only one-third considered it beneficial to perform CPR as a layperson. In addition, healthcare respondents (p<0.001), younger (p<0.05) and more educated respondents (p<0.001) earned higher scores on the knowledge of CPR skills. Only 5.3% had perfect scores on a CPR skills test. Notably, respondents with relatives suffering from heart disease had significantly less training experience and CPR knowledge than those without (p<0.001).

CONCLUSIONS

Although the attitudes towards learning CPR are very positive, there was a lack of knowledge on this topic among the general public. This study demonstrates an urgent need to boost awareness and training in CPR in South China, especially among people whose relatives have heart disease.

History of cardiopulmonary resuscitation in ancient China: a narrative review

Modern cardiopulmonary resuscitation (CPR) comprises an open airway, artificial ventilation, chest compressions and, if necessary, defibrillation. CPR has been intensively studied and tested to perfect an integrated and effective resuscitation system in the West. However, CPR efforts in China has been understudied and underreported. CPR has been performed for more than 2000 years in China. As early as the third century BC, a Chinese doctor named Zhongjing Zhang presented a detailed program to save patients from suicide by hanging in the book entitled “Synopsis of the Golden Chamber”. Dr. Zhang proposed “not only to save the body, but also to save the spirit”, which remains a guiding principle in modern resuscitation: to not only ensure cardiopulmonary recovery but also preserve the brain function. We aim to review and summarize efforts of CPR in China from a historic point of view.

Clinical outcomes from out-of-hospital cardiac arrest in low-resource settings - A scoping review

AIM OF THE SCOPING REVIEW

Scientific recommendations on resuscitation are typically formulated from the perspective of an ideal resource environment, with little consideration of applicability in lower-income countries. We aimed to determine clinical outcomes from out-of-hospital cardiac arrest (OHCA) in low-resource countries, to identify shortcomings related to resuscitation in these areas and possible solutions, and to suggest future research priorities.

DATA SOURCES

This scoping review was part of the continuous evidence evaluation process of the International Liaison Committee on Resuscitation (ILCOR), and was performed following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews. We identified low-resource countries as countries with a low- or middle gross national income per capita (World Bank data). We performed a literature search on outcomes after OHCA in these countries, and we extracted data on the outcome. We applied descriptive statistics and conducted a post-hoc correlation analysis of cohort size and ROSC rates.

RESULTS

We defined 24 eligible studies originating from middle-income countries, but none from low-income regions, suggesting a reporting bias. The number of reported patients in these studies ranged from 54 to 3214. Utstein-style reporting was rarely used. Return of spontaneous circulation varied from 0% to 62%. Fifteen studies reported on survival to hospital discharge (between 1.0 and 16.7%) or favourable neurological outcome (between 1.0 and 9.3%). An inverse correlation was found for study cohort size and the rate of return of spontaneous circulation (ρ = -0.48, p = 0.034).

CONCLUSION

Studies of OHCA outcomes in low-resource countries are heterogeneous and may be compromised by reporting bias. Minimum cardiopulmonary resuscitation standards for low-resource settings should be developed collaboratively involving local experts, respecting culture and context while balancing competing health priorities.

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.

The Effects of Dexmedetomidine Post-Conditioning on Cardiac and Neurological Outcomes After Cardiac Arrest and Resuscitation in Swine

INTRODUCTION

One of the main contents of post-resuscitation care is to alleviate cardiac and neurological damage in cardiac arrest (CA) victims. Recently, dexmedetomidine pre- and post-conditioning have been shown to both effectively protect the heart and brain against regional ischemia reperfusion injury. In this study, we investigated the effects of dexmedetomidine post-conditioning on cardiac and neurological outcomes after CA and resuscitation in swine.

METHODS

A total of 28 male domestic swine were randomized into four groups: sham, cardiopulmonary resuscitation (CPR), low-dose dexmedetomidine post-conditioning (LDP), and high-dose dexmedetomidine post-conditioning (HDP). Sham animals underwent the surgical preparation only. The animal model was established by 8 min of CA and then 5 min of CPR. After the animal was successfully resuscitated, a loading dose of 0.25 μg/kg of dexmedetomidine was intravenously injected followed by continuous infusion of 0.25 μg/kg/h for 6 h in the LDP group, and meanwhile a double dose of dexmedetomidine was similarly administered in the HDP group. The same amount of saline was given in the other two groups. All the resuscitated animals were monitored for 6 h and then returned to their cages for an additional 18 h of observation.

RESULTS

After resuscitation, significantly greater cardiac, neurological dysfunction, and injuries were observed in all animals experiencing CA and resuscitation when compared with the sham group. However, the severity of cardiac and neurological damage was significantly milder in the two dexmedetomidine-treated groups than in the CPR group. Dexmedetomidine post-conditioning also significantly decreased post-resuscitation tissue inflammation, oxidative stress, and cell apoptosis and necroptosis in the heart and brain when compared with the CPR group. In addition, these protective effects produced by dexmedetomidine post-conditioning were significantly greater in the HDP group than in the LDP group.

CONCLUSIONS

Dexmedetomidine post-conditioning dose-dependently improved post-resuscitation cardiac and neurological outcomes through the inhibition of tissue inflammation, oxidative stress, and cell apoptosis and necroptosis.

Adenoviral βARKct Cardiac Gene Transfer Ameliorates Postresuscitation Myocardial Injury in a Porcine Model of Cardiac Arrest

OBJECTIVE

The aim of the study was to determine whether the inhibition of the G-protein-coupled receptor kinase 2 by adenoviral βARKct cardiac gene transfer can ameliorate postresuscitation myocardial injury in pigs with cardiac arrest (CA) and explore the mechanism of myocardial protection.

METHODS

Male landrace domestic pigs were randomized into the sham group (anesthetized and instrumented, but ventricular fibrillation was not induced) (n = 4), control group (ventricular fibrillation 8 min, n = 8), and βARKct group (ventricular fibrillation 8 min, n = 8). Hemodynamic parameters were monitored continuously. Blood samples were collected at baseline, 30 min, 2 h, 4 h, and 6 h after the return of spontaneous circulation (ROSC). Left ventricular ejection fraction was assessed by echocardiography at baseline and 6 h after ROSC. These animals were euthanized, and the cardiac tissue was removed for analysis at 6 h after ROSC.

RESULTS

Compared with those in the sham group, left ventricular +dp/dtmax, -dp/dtmax, cardiac output (CO), and ejection fraction (EF) in the control group and the βARKct group were significantly decreased at 6 h after the restoration of spontaneous circulation. However, the βARKct treatment produced better left ventricular +dp/dtmax, -dp/dtmax, CO, and EF after ROSC. The βARKct treatment also produced lower serum cardiac troponin I, CK-MB, and lactate after ROSC. Furthermore, the adenoviral βARKct gene transfer significantly increased β1 adrenergic receptors, SERCA2a, RyR2 levels, and decreased GRK2 levels compared to control.

CONCLUSIONS

The inhibition of GRK2 by adenoviral βARKct cardiac gene transfer can ameliorate postresuscitation myocardial injury through beneficial effects on restoring the sarcoplasmic reticulum Ca-handling proteins expression and upregulating the β1-adrenergic receptor level after cardiac arrest.

Serial disseminated intravascular coagulation score with neuron specific enolase predicts the mortality of cardiac arrest-a pilot study

Background

Prognosis in cardiac arrest (CA) patients has been challenging. We sought to investigate prognostic value combining serial disseminated intravascular coagulation (DIC) score and neuron-specific enolase (NSE) in out-of-hospital cardiac arrest (OHCA) patients.

Methods

Sixty-one consecutive patients successfully resuscitated after CA were included in the analysis. DIC score and NSE levels were serially analyzed after return of spontaneous circulation (ROSC). The outcome measure was death before hospital discharge. Prognostication performance was assessed as the area under the receiver-operating characteristics curve (AUC). Hosmer-Lemeshow test was used for internal validation of predictive models. Calibration curves were drawn to visualize the results of tests.

Results

The NSE levels continued to increase in the first 72 h in non-survivors. In survivors, the NSE levels decreased after 48 h. Both DIC score at 48 h and NSE level at 48 h were good predictors of outcome. The AUC for predictive mortality in OHCA patients was 0.869 (95% CI, 0.781-0.956) for DIC score at 48 h combining NSE at 24 h, 0.878 (95% CI, 0.791-0.965) for DIC score at 48 h combining NSE at 48 h and 0.882 (95% CI, 0.792-0.972) for DIC score at 48 h combining NSE at 72 h, respectively. Significance of Hosmer-Lemeshow test was 0.488, 0.324, 0.011 for each combination.

Conclusions

Serial DIC score combined with measurement of NSE levels is a useful and accessible tool for prognostication following OHCA.

NLRP3 inflammasome-mediated microglial pyroptosis is critically involved in the development of post-cardiac arrest brain injury

Background

Brain injury is the leading cause of death and disability in survivors of cardiac arrest, where neuroinflammation is believed to play a pivotal role, but the underlying mechanism remains unclear. Pyroptosis is a pro-inflammatory form of programmed cell death that triggers inflammatory response upon infection or other stimuli. This study aims to understand the role of microglial pyroptosis in post-cardiac arrest brain injury.

Methods

Sprague-Dawley male rats underwent 10-min asphyxial cardiac arrest and cardiopulmonary resuscitation or sham-operation. Flow cytometry analysis, Western blotting, quantitative real-time polymerase chain reaction (qRT-PCR), co-immunoprecipitation, and immunofluorescence were used to evaluate activated microglia and CD11b-positive leukocytes after cardiac arrest and assess inflammasome activation and pyroptosis of specific cellular populations. To further explore the underlying mechanism, MCC950 or Ac-YVAD-cmk was administered to block nod-like receptor family protein 3 (NLRP3) or caspase-1, respectively.

Results

Our results showed that, in a rat model, successful resuscitation from cardiac arrest resulted in microglial pyroptosis and consequential inflammatory infiltration which was mediated by the activation of NLRP3 inflammasome. Targeting NLRP3 and caspase-1, the executor of pyroptosis, with selective inhibitors MCC950 and Ac-YVAD-cmk treatment significantly prevented microglial pyroptosis, reduced infiltration of leukocytes, improved neurologic outcome, and alleviated neuro-pathological damages after cardiac arrest in modeling rats.

Conclusions

This study demonstrates that microglial pyroptosis mediated by NLRP3 inflammasome is critically involved in the pathogenesis of post-cardiac arrest brain injury and provides a new therapeutic strategy.

Cardiopulmonary Resuscitation in Intensive Care Unit Patients With Coronavirus Disease 2019

Cardiopulmonary resuscitation (CPR) in patients with severe acute respiratory syndrome coronavirus-2–associated disease (coronavirus disease 2019) poses a unique challenge to health- care providers due to the risk of viral aerosolization and disease transmission. This has caused some centers to modify existing CPR procedures, limit the duration of CPR, or consider avoiding CPR altogether. In this review, the authors propose a procedure for CPR in the intensive care unit that minimizes the number of personnel in the immediate vicinity of the patient and conserves the use of scarce personal protective equipment. Highlighting the low likelihood of successful resuscitation in high-risk patients may prompt patients to decline CPR. The authors recommend the preemptive placement of central venous lines in high-risk patients with intravenous tubing extensions that allow for medication delivery from outside the patients’ rooms. During CPR, this practice can be used to deliver critical medications without delay. The use of a mechanical compression system for CPR further reduces the risk of infectious exposure to health- care providers. Extracorporeal membrane oxygenation should be reserved for patients with few comorbidities and a single failing organ system. Reliable teleconferencing tools are essential to facilitate communication between providers inside and outside the patients' rooms. General principles regarding the ethics and peri-resuscitative management of coronavirus 2019 patients also are discussed.

Time Trends in Cardiovascular Disease Mortality Across the BRICS

Background:

Brazil, Russia, India, China, and South Africa (BRICS) are emerging economies making up almost half the global population. We analyzed trends in cardiovascular disease (CVD) mortality across the BRICS and associations with age, period, and birth cohort.

Methods:

Mortality estimates were derived from the Global Burden of Disease Study 2017. We used age-period-cohort modeling to estimate cohort and period effects in CVD between 1992 and 2016. Period was defined as survey year, and period effects reflect population-wide exposure at a circumscribed point in time. Cohort effects are defined as differences in risks across birth cohort. Net drift (overall annual percentage change), local drift (annual percentage change in each age group), longitudinal age curves (expected longitudinal age-specific rate), and period (cohort) relative risks were calculated.

Results:

In 2016, there were 8.4 million CVD deaths across the BRICS. Between 1992 and 2016, the reduction in CVD age-standardized mortality rate in BRICS (−17%) was less than in North America (−39%). Eighty-eight percent of the increased number of all-cause deaths resulted from the increase in CVD deaths. The age-standardized mortality rate from stroke and hypertensive heart disease declined by approximately one-third across the BRICS, whereas ischemic heart disease increased slightly (2%). Brazil had the largest age-standardized mortality rate reductions across all CVD categories, with improvement both over time and in recent birth cohorts. South Africa was the only country where the CVD age-standardized mortality rate increased. Different age-related CVD mortality was seen in those ≥50 years of age in China, ≤40 years of age in Russia, 35 to 60 years of age in India, and ≥55 years of age in South Africa. Improving period and cohort risks for CVD mortality were generally found across countries, except for worsening period effects in India and greater risks for ischemic heart disease in Chinese cohorts born in the 1950s and 1960s.

Conclusions:

Except for Brazil, reductions of CVD mortality across the BRICS have been less than that in North America, such that China, India, and South Africa contribute an increasing proportion of global CVD deaths. Brazil’s example suggests that prevention policies can both reduce the risks for younger birth cohorts and shift the risks for all age groups over time.

The global survival rate among adult out-of-hospital cardiac arrest patients who received cardiopulmonary resuscitation: a systematic review and meta-analysis

Background

To quantitatively summarize the available epidemiological evidence on the survival rate of out-of-hospital cardiac arrest (OHCA) patients who received cardiopulmonary resuscitation (CPR).

Methods

We systematically searched the PubMed, Embase, and Web of Science databases, and the references of retrieved articles were manually reviewed to identify studies reporting the outcome of OHCA patients who received CPR. The overall incidence and outcome of OHCA were assessed using a random-effects meta-analysis.

Results

A total of 141 eligible studies were included in this meta-analysis. The pooled incidence of return of spontaneous circulation (ROSC) was 29.7% (95% CI 27.6–31.7%), the rate of survival to hospital admission was 22.0% (95% CI 20.7–23.4%), the rate of survival to hospital discharge was 8.8% (95% CI 8.2–9.4%), the pooled 1-month survival rate was 10.7% (95% CI 9.1–13.3%), and the 1-year survival rate was 7.7% (95% CI 5.8–9.5%). Subgroup analysis showed that survival to hospital discharge was more likely among OHCA patients whose cardiac arrest was witnessed by a bystander or emergency medical services (EMS) (10.5%; 95% CI 9.2–11.7%), who received bystander CPR (11.3%, 95% CI 9.3–13.2%), and who were living in Europe and North America (Europe 11.7%; 95% CI 10.5–13.0%; North America: 7.7%; 95% CI 6.9–8.6%). The survival to discharge (8.6% in 1976–1999 vs. 9.9% in 2010–2019), 1-month survival (8.0% in 2000–2009 vs. 13.3% in 2010–2019), and 1-year survival (8.0% in 2000–2009 vs. 13.3% in 2010–2019) rates of OHCA patients who underwent CPR significantly increased throughout the study period. The Egger’s test did not indicate evidence of publication bias for the outcomes of OHCA patients who underwent CPR.

Conclusions

The global survival rate of OHCA patients who received CPR has increased in the past 40 years. A higher survival rate post-OHCA is more likely among patients who receive bystander CPR and who live in Western countries.

Electronic supplementary material

The online version of this article (10.1186/s13054-020-2773-2) contains supplementary material, which is available to authorized users.

An audio-visual review model enhanced one-year retention of cardiopulmonary resuscitation skills and knowledge: A randomized controlled trial

BACKGROUND

As the majority of out-of-hospital cardiac arrest occur at patients' homes, implementing high-quality cardiopulmonary resuscitation by family members is critical in improving patient outcomes. However, the survival rate remains low due to low bystander cardiopulmonary resuscitation rate and rapid skill deterioration in individuals who complete the training.

OBJECTIVES

To evaluate the effectiveness of audio-visual review model and audio-visual-practice review model on cardiopulmonary resuscitation skill retention 12 months after training.

DESIGN

A randomized, double-blind, placebo controlled, and three-arm parallel study.

PARTICIPANTS

A total of 641 family members of patients at high risk of out-of-hospital cardiac arrest enrolled in the study and 448 participants completed the follow-up.

METHODS

Family members from Beijing, China were recruited. All families underwent initial cardiopulmonary resuscitation training. Their cardiopulmonary resuscitation skill and knowledge were assessed immediately after training. Trainees who were rated "adequate skill and knowledge" were assigned randomly into one of three groups. The control group was given a cardiopulmonary resuscitation instruction booklet and a placebo-DVD without any reminders. Both audio-visual and audio-visual-practice groups were reinforced by a telephone reminder every 3 months. The audio-visual-practice group was also asked to simultaneously practice the skills while watching the instructional-DVD. The trainees' cardiopulmonary resuscitation skills and knowledge were re-assessed 12 months after training.

RESULTS

The retention rates of cardiopulmonary resuscitation skills in both audio-visual-practice (N = 177) and audio-visual (N = 157) groups were higher than that in control group (N = 114) 12 months after training (all P-values  < 0.001). The cardiopulmonary resuscitation skill retention rate in audio-visual-practice group was higher than that in audio-visual group (49.7% vs 36.9%, P = 0.019), but no difference was found in intention-to-treat analysis (32.1% vs 27.1%, P = 0.230). Both audio-visual-practice and audio-visual groups had higher correct rates on all skill elements than that in control group (all P-values < 0.05). The cardiopulmonary resuscitation knowledge scores in both audio-visual-practice and audio-visual groups were higher than that in control group (all P-values < 0.001). However, no significant difference was found between audio-visual-practice and audio-visual groups (P = 0.243).

CONCLUSIONS

Both audio-visual-practice and audio-visual review models demonstrated better long-term retention of cardiopulmonary resuscitation skills for families of people at higher risk of out-of-hospital cardiac arrest. (Registration number: chiCTR-TRC-12002149).