Cardiac Arrest Research Research Articles

Clinical Factors Associated with Obstructive Coronary Artery Disease in Patients with Out-of-Hospital Cardiac Arrest: Data from the Korean Cardiac Arrest Research Consortium (KoCARC) Registry.

BackgroundAlthough coronary artery disease (CAD) is a major cause of out-of-hospital cardiac arrest (OHCA), there has been no convinced data on the necessity of routine invasive coronary angiography (ICA) in OHCA. We investigated clinical factors associated with obstructive CAD in OHCA.MethodsData from 516 OHCA patients (mean age 58 years, 83% men) who underwent ICA after resuscitation was obtained from a nation-wide OHCA registry. Obstructive CAD was defined as the lesions with diameter stenosis ≥ 50% on ICA. Independent clinical predictors for obstructive CAD were evaluated using multiple logistic regression analysis, and their prediction performance was compared using area under the receiver operating characteristic curve with 10,000 repeated random permutations.ResultsAmong study patients, 254 (49%) had obstructive CAD. Those with obstructive CAD were older (61 vs. 55 years, P < 0.001) and had higher prevalence of hypertension (54% vs. 36%, P < 0.001), diabetes mellitus (29% vs. 21%, P = 0.032), positive cardiac enzyme (84% vs. 74%, P = 0.010) and initial shockable rhythm (70% vs. 61%, P = 0.033). In multiple logistic regression analysis, old age (≥ 60 years) (odds ratio [OR], 2.01; 95% confidence interval [CI], 1.36–3.00; P = 0.001), hypertension (OR, 1.74; 95% CI, 1.18–2.57; P = 0.005), positive cardiac enzyme (OR, 1.72; 95% CI, 1.09–2.70; P = 0.019), and initial shockable rhythm (OR, 1.71; 95% CI, 1.16–2.54; P = 0.007) were associated with obstructive CAD. Prediction ability for obstructive CAD increased proportionally when these 4 factors were sequentially combined (P < 0.001).ConclusionIn patients with OHCA, those with old age, hypertension, positive cardiac enzyme and initial shockable rhythm were associated with obstructive CAD. Early ICA should be considered in these patients.

Abstract 252: Older Brains vs. Younger Brains: Effect of Cardiac Arrest on Hemodynamic Fluctuations and Neurologic Impairment in a Rodent Model

Introduction: The patient suffering from cardiac arrest (CA) is elderly. Numerous laboratory experimental studies of CA are based on the young rodent model. Post-CA patients are often hemodynamically unstable, hypotension is correlated with poor neurologic outcomes. To improve the clinical relevance of CA research in laboratory, we compared the effect of CA in retired breeder (RB) and young group (YG) rats. Hypothesis: The objective of this study was to investigate the effect of CA on systemic arterial blood pressure and neurologic impairment outcomes in RB and YG rats. We hypothesize that RB rats will demonstrate lower mean arterial pressure (MAP) and delayed restoration of electroencephalogram (EEG) associated with neurologic recovery. Methods: Male RB Wistar rats (10-12 months, n=7) and male YG Wistar rats (2-2.5 months, n=6) were subjected to 7 min of asphyxia CA. Multiple parameters including MAP, EEG were recorded. The neurological outcomes were evaluated via neurological deficit score (NDS). Results: There was no significant difference between the two groups’ pre-arrest baseline characteristics except for the body weights (RB vs YG as 581 ± 54 vs 395 ± 9 g). This includes baseline heart rate, MAP, EEG and time to CA. After CA, RB rats showed significantly longer time to achieve return of spontaneous circulation (ROSC) compared to the YG (123 ± 42 vs 81 ± 9 sec, p &lt; 0.05). RB rats showed lower MAP post ROSC compared to YG (98.8 ± 19.0 vs 115.0 ± 16.2 mmHg, p &lt; 0.05 during 0-30 min post ROSC). The recovery sequences of EEG post ROSC are as follows: non-detectable cortical activity (non-DCA); intermittent cortical activity (ICA); continuous cortical activity (CCA). Analysis of recovering EEG indicates a higher gamma fraction for the RB rats during CCA period (p&lt;0.03). High gamma is a surrogate for better EEG recovery for complex cognitive function. NDS scores were no significant difference for both groups from 4 hours to 7 days post ROSC. Conclusion: It appears that older rats have slower hemodynamic recovery post ROSC compared to younger rats. The neurologic deficits are similar in both groups, but cognitive recovery by Gamma fraction seems better in RB. More study is needed to fully understand the effect of aging on the post ROSC brain.

Korean Cardiac Arrest Research Consortium (KoCARC): rationale, development, and implementation.

ObjectiveThis study aimed to describe the conceptualization, development, and implementation processes of the newly established Korean Cardiac Arrest Resuscitation Consortium (KoCARC) to improve out-of-hospital cardiac arrest (OHCA) outcomes.MethodsThe KoCARC was established in 2014 by recruiting hospitals willing to participate voluntarily. To enhance professionalism in research, seven research committees, the Epidemiology and Preventive Research Committee, Community Resuscitation Research Committee, Emergency Medical System Resuscitation Research Committee, Hospital Resuscitation Research Committee, Hypothermia and Postresuscitation Care Research Committee, Cardiac Care Resuscitation Committee, and Pediatric Resuscitation Research Committee, were organized under a steering committee. The KoCARC registry was developed with variables incorporated in the currently existing regional OHCA registries and Utstein templates and were collected via a web-based electronic database system. The KoCARC study population comprises patients visiting the participating hospitals who had been treated by the emergency medical system for OHCA presumed to have a cardiac etiology.ResultsA total of 62 hospitals volunteered to participate in the KoCARC, which captures 33.0% of the study population in Korea. Web-based data collection started in October 2015, and to date (December 2016), there were 3,187 cases compiled in the registry collected from 32 hospitals.ConclusionThe KoCARC is a self-funded, voluntary, hospital-based collaborative research network providing high level evidence in the field of OHCA and resuscitation. This paper will serve as a reference for subsequent KoCARC manuscripts and for data elements collected in the study.

Delphi Analysis of Science Gaps in the 2015 American Heart Association Cardiac Arrest Guidelines.

BackgroundCurrent cardiac arrest guidelines have limited high‐quality scientific evidence to support recommendations for care. The quality of scientific evidence on which guidelines are based may correlate with improved patient outcomes and meaningful survival. We sought to develop a prioritized list of knowledge gaps in resuscitation to assist researchers, policy makers, and funding agencies in their decision‐making process.Methods and ResultsA 4‐stage modified Delphi method was used with a panel of cardiac arrest experts. Experts addressed the prompt: “What are the top 3 gaps in knowledge involving cardiac arrest care that should be research priorities for National Institutes of Health/American Heart Association funding to have the greatest impact on public health?” Knowledge gaps were identified in the initial round, rated in a second round, and rank ordered in the third round, and they underwent final review and consensus (final round). The outcome was 10 knowledge gaps, with prioritization of the top 3 gaps. A total of 61 gaps, with 19 distinct themes, were identified by participants. The 10 knowledge gaps most likely to affect public health identified by the expert panel included, in order, the following: telecommunicator cardiopulmonary resuscitation, hemodynamic monitoring for goal‐directed resuscitation, reasons why bystanders fail to respond, optimization of postarrest care, out‐of‐hospital cardiac arrest identification and response, individualizing resuscitation strategies, predicting patients at risk, tools for neuroprognostication, optimal airway management, and optimizing educational strategies.ConclusionsTen priorities for cardiac arrest research were identified, but consensus was not reached on the prioritized top 3. Future research should address these gaps to potentially improve resuscitation guideline evidence quality.

The present and future of cardiac arrest care: international experts reach out to caregivers and healthcare authorities.

The purpose of this review is to describe the epidemiology of out-of-hospital cardiac arrest (OHCA), disparities in organisation and outcome, recent advances in treatment and ongoing controversies. We also outline the standard of care that should be provided by the critical care specialist and propose future directions for cardiac arrest research. Narrative review with contributions from international resuscitation experts. Although it is recognised that survival rates from OHCA are increasing there is considerable scope for improvement and many countries have implemented national strategies in an attempt to achieve this goal. More resources are required to enable high-quality randomised trials in resuscitation. Increasing international collaboration should facilitate resuscitation research and knowledge translation. The International Liaison Committee on Resuscitation (ILCOR) has adopted a continuous evidence review process, which facilitate the implementation of resuscitation interventions proven to improve patient outcomes.

“Resuscitation time bias”—A unique challenge for observational cardiac arrest research

Observational studies are prone to a number of biases. One of these is immortal time bias. In this manuscript, we discuss immortal time bias as it pertains to post-cardiac arrest research and describes a related bias which we term “resuscitation time bias”. This bias can occur when studying exposures during cardiac arrest. In this unique situation, an exposure is more likely to occur the longer the cardiac arrest continues. Since length of resuscitation is strongly associated with worse outcome, this will bias the results toward a harmful effect of the exposure. We discuss this bias and present methods to account for it.

Swine model in cardiopulmonary resuscitation research

Cardiac Arrest (CA) constitutes a real medical emergency. Various experimental models have been developed in order to test experimental treatments. Animal models that have been used in CA research are rodents, rabbits, cats and dogs, primates and swine. Among these, swine are used more often. The reason behind this choice is mostly its close resemblance to the human cardiac anatomy and physiology. Various haemodynamic variables have been investigated as predictors of the return of spontaneous circulation (ROSC). Coronary Perfusion Pressure (CPP) is the only proven predictor for ROSC. CPP, which is responsible for myocardial perfusion, greatly augments during chest compressions. ROSC and therefore survival after CA has been associated with CCP values greater than 15 mmHg for humans and 25 mmHg for animals. For the experimental induction of CA various electric sources have been used. All these experimental devices could be potentially dangerous for researchers, even though, no incidence of electrocution has been reported in the international literature. The ordinary cadmium battery appears to be safer and is an extremely effective way of inducing cardiac arrest.

Gains of Continuing Resuscitation in Refractory Out-of-hospital Cardiac Arrest: A Model-based Analysis to Identify Deaths Due to Intra-arrest Prognostication

Objective: Prognostication bias, in which a clinician predicts a negative outcome and terminates resuscitation (TR) thereby ensuring a poor outcome, is a rarely identified limitation of out-of-hospital cardiac arrest (OHCA) research. We sought to estimate the number of deaths due to intra-arrest prognostication in a cohort of OHCA's, and use this data to estimate the incremental benefit of continuing resuscitation. Methods: This study examined a cohort of consecutive non-traumatic EMS-treated OHCAs from a provincial ambulance service, between 2007 and 2011 inclusive. We used Cox and logistic regression modeling, adjusting for Utstein covariates, to estimate the probability of ROSC, survival, and favorable neurological outcomes as a function of resuscitation time, and applied these models to estimate the number of missed survivors in those who had TR (prior to 20, 30, or 40 minutes). We determined the time juncture at which (1) the likelihood of survival fell below 1%, and (2) the proportion of survivors who had achieved ROSC exceeded 99%. Results: Of 5674 adult EMS-treated cases, 46% achieved ROSC, and 12% survived. The median time of TR was 27.0 minutes (IQR 19.0–35.0). Continuing resuscitation until 40 minutes yielded an estimated 17 additional survivors (95% CI 13–21), 10 (95% CI 7–13) with favorable neurological outcomes. The probability of survival of those in refractory arrest decreased below 1% at 28 minutes (95% CI 24–30 minutes). At 36 minutes (95% CI 34–38 minutes) >99% of survivors had achieved ROSC. Conclusion: We identified possible deaths due to intra-arrest prognostication. Resuscitation should be continued for a minimum of 30 minutes in all patients, however for those with initial shockable rhythms 40 minutes appears to be warranted. Interventional trials and observational studies should standardize or adjust for duration of resuscitation prior to TR.

No small matter: pediatric resuscitation.

To present advancements in pediatric cardiac arrest research, highlighting articles most relevant to clinical practice published since the latest international guidelines for cardiopulmonary resuscitation (CPR). Clinical trials examining targeted temperature management in children support avoidance of hyperthermia for both pediatric in-hospital cardiac arrest (PIHCA) and out-of-hospital cardiac arrest (POHCA), but no statistically significant outcome differences were confirmed comparing 33 and 36 °C in the limited populations studied. Retrospective analyses of population-based POHCA registries revealed several associations: both bystander CPR and public-access defibrillation were associated with improved POHCA outcomes; conflicting results overshadow the benefits of conventional versus compression-only CPR; extracorporeal CPR was associated with improved PIHCA outcomes regardless of cause; intubation in PIHCA was associated with decreased survival, whereas there were no significant differences in outcomes between advanced airway management and bag-valve-mask ventilation in POHCA; and early epinephrine delivery in nonshockable rhythms during PIHCA was associated with improved outcomes. Length, age, and weight-based dosing systems can reduce time to medication delivery, quantitative errors, and anxiety among care providers. Mounting evidence continues to align management priorities for resuscitation of children and adults.

We need to include bystander first aid in trauma research

BackgroundThe chain of trauma survival is a concept that originated in the area of out-of-hospital cardiac arrest (OHCA) and was adapted to the treatment of trauma. In out-of-hospital cardiac arrest research into bystander first aid has resulted in improved outcome. Whereas, in trauma research the first link of the chain of survival is almost ignored.MethodsIn OHCA, cardiopulmonary resuscitation (CPR) from bystanders has been subject of a vast amount of research, as well as measures and programs to raise the rate of bystander CPR to cardiac arrest victims. These efforts have resulted in improved survival. The research effort has been well grounded in the research community, as demonstrated by its natural inclusion in the uniform reporting template (Utstein) for the treatment of OHCA. In trauma the bystander may contribute by providing an open airway, staunch bleedings, or prevent hypothermia. In trauma however, while the chain of survival has been adopted along with it distinct links, including bystander first aid, the consensus-based uniform reporting template for trauma (the Utstein template) does not include the bystander first aid efforts. There is extremely little research on what first aid measures bystanders provide to trauma victims, and on what impact such measures have on outcome. An important step to improve research on bystander first aid in trauma would be to include this as part of the uniform reporting template for traumaConclusionThe lack of research on bystander first aid makes the first link in the trauma chain of survival the weakest link. We, the trauma research community, should either improve our research and knowledge in this area, or remove the link from the chain of survival

Surrogate endpoints and competing risk of death in cardiac arrest research.

We urgently need new therapies to improve outcomes after cardiac arrest. Initial studies typically target surrogate endpoints, and these studies help to inform subsequent larger trials that are powered to measure more patient-orientated clinical outcomes such as survival. The competing risk of death and premature assessment of neurological prognosis pose significant challenges to measuring these surrogate endpoints after cardiac arrest.

Neurologic outcome, health-related quality of life, anxiety and symptoms of depression among in-hospital cardiac arrest survivors

Purpose: Most cardiac arrest research has focused on survival inan out-of-hospital context. The knowledge of health and quality of life is sparse, especially regarding in-hospital cardiac arrest (I ...

Derivation and initial application of a standard population for out-of-hospital cardiac arrest (SPOHCA)

AimWhile adjusting data for age, sex, race and/or socio-economic status is well established in out-of-hospital cardiac arrest (OHCA) research, there are shortcomings to reporting and comparing population-based OHCA outcomes. The purpose of this study was to derive a case-based standard population specific to EMS treated adult OHCA (SPOHCA) in the U.S., and demonstrate its application. MethodsThe proposed SPOHCA was developed from three sources of multi-site OHCA data: the Cardiac Arrest Registry to Enhance Survival (CARES); the National EMS Information System (NEMSIS); and a published report from the Resuscitation Outcomes Consortium (ROC). OHCA data from a single EMS system were then used to demonstrate the application of SPOHCA. We report raw survival, population-based survival adjusted to the U.S. population, and the new SPOHCA-adjusted survival. ResultsObserved raw survival was 12.3%. Adjustment to the demographic make-up of the adult U.S. population produced an adjusted incidence of 94.2 OHCA per 100,000p-y, with a survival rate of 9.8 per 100,000p-y. Using the proposed SPOHCA to adjust survival data produced an adjusted survival rate of 12.4%. ConclusionA case-based standard population provides for more practical interpretation of reported OHCA outcomes. We encourage a more widespread effort involving multiple stakeholders to further explore the effects of adjusting OHCA outcomes using the proposed SPOHCA instead of population-based demographics.

Does adrenaline improve long-term outcomes after out-of-hospital cardiac arrest?

Adrenaline has been an integral component of advanced life support from the birth of modern cardiopulmonary resuscitation (CPR) in the early 1960s. The findings from randomised trials and observational studies indicate that giving adrenaline in out-of-hospital cardiac arrest (OHCA) increases the rate of return of spontaneous circulation (ROSC) but that longer-term outcomes (survival to hospital discharge and neurologically favourable survival) are either worse or, at best, neutral. PARAMEDIC2: The Adrenaline Trial should answer once and for all the question of whether giving doses of adrenaline 1 mg during CPR improves long-term outcome from OHCA. As such, it is the most important cardiac arrest research study ever to be undertaken in the United Kingdom.

Abstract 67: Cardiac Arrest and Surgical Case Volume, Household Income and Availability of Trauma and Cardiac Surgery Are Associated with Higher Risk-Standardized Survival After Cardiac Arrest Among University Hospital Consortium Institutions in 2012

Objective: Wide variation exists in cardiac arrest survival. Historically cardiac arrest research has focused upon clinical pre-arrest and intra-arrest factors to explain this variation in outcomes. In-hospital post-arrest care is increasingly recognized as an important aspect of survival. We sought to identify hospital characteristics associated with improved cardiac arrest survival. Methods: We examined all participating hospitals in the University Hospital Consortium (UHC) clinical database with more than 25 adult cardiac arrests in 2012. Cases were identified using International Classification of Diseases, 9th Edition, code 427.5 (cardiac arrest) or 99.60 (CPR), excluding prisoners, pregnant patients, transfers, and hospice patients. We estimated hospital-specific risk-standardized survival rates (RSSRs) using hierarchical logistic regression, adjusting for individual risk of mortality. Institutions in the highest RSSR quartile were compared with those in the lowest three quartiles using Pearson chi-square tests of association. Results: UHC institutions admitted 3,686,296 patients in 2012, of which 33,700 patients experienced cardiac arrest. Overall survival was 42.3% (95% CI 41.8-42.9) with median RSSR of 42.7% (IQR 35.5-50.8). Hospitals in the highest quartile of RSSR had higher cardiac arrest volume (median 193 vs. 150, p-value 0.019), higher annual surgical operation volume (21,177 vs. 14,122, 0.007), cared for patients from catchment areas with higher household income ($60,753 vs. $56,424, 0.027), and were more likely to be a trauma (79% vs 59%, 0.024) or cardiac surgery center (91% vs 70%, 0.007). In addition, hospital size (477 vs 415 beds, 0.060) and teaching status (77% vs. 62%, 0.067) demonstrated a trend toward association with higher RSSR. Conclusion: Among hospitals in the UHC, those with higher cardiac arrest and surgical case volume, patient household income, and availability of trauma and cardiac surgery were associated with improved RSSR.

Outcome reporting in cardiac arrest randomised controlled trials

Background: It is known there is heterogeneity in outcome reporting in the field of cardiac arrest research. This review was conducted to determine the extent of this problem and identify the outcomes that are currently reported in randomised controlled trials. We plan to use the outcome measures extracted as a starting point for the development of a core outcome set.

AP075 AED: access, ethics and data protection in out-of-hospital cardiac arrest research

AP075 AED: access, ethics and data protection in out-of-hospital cardiac arrest research

Development of a data dictionary for the Strategies for Post Arrest Resuscitation Care (SPARC) network for post cardiac arrest research

Background The widely accepted Utstein style has standardized data collection and analysis in resuscitation and post resuscitation research. However, collection of many of these variables poses significant practical challenges. In addition, several important variables in post resuscitation research are missing. Objective Our aim was to develop a comprehensive data dictionary and web-based data collection tool as part of the Strategies for Post Arrest Resuscitation Care (SPARC) Network project, which implemented a knowledge translation program for post cardiac arrest therapeutic hypothermia in 37 Ontario hospitals. Methods A list of data variables was generated based on the current Utstein style, previous studies and expert opinion within our group of investigators. We developed a data dictionary by creating clear definitions and establishing abstraction instructions for each variable. The data dictionary was integrated into a web-based collection form allowing for interactive data entry. Two blinded investigators piloted the data collection tool, by performing a retrospective chart review. Results A total of 454 variables were included of which 400 were Utstein, 2 were adapted from existing studies and 52 were added to address missing elements. Kappa statistics for two outcome variables, survival to discharge and induction of therapeutic hypothermia were 0.86 and 0.64, respectively. Conclusion This is the first attempt in the literature to develop a data dictionary as part of a standardized, pragmatic data collection tool for post cardiac arrest research patients. In addition, our dataset defined important variables that were previously missing. This data collection tool can serve as a reference for future trials in post cardiac arrest care.

Design of the Circulation Improving Resuscitation Care (CIRC) Trial: A new state of the art design for out-of-hospital cardiac arrest research

PurposeMechanical chest compression devices, such as the AutoPulse®, have been developed to overcome problems associated with manual CPR (M-CPR). Animal and human studies have shown that AutoPulse CPR improves hemodynamic parameters over M-CPR. However, human studies conducted in the prehospital setting have conflicting results as to the AutoPulse's efficacy in improving survival. The Circulation Improving Resuscitation Care (CIRC) Trial is designed to evaluate the effectiveness of integrated AutoPulse-CPR (iA-CPR) (i.e., M-CPR followed by AutoPulse®-CPR) in a randomized controlled trial that addresses methodological issues that may have influenced the results of previous studies. MethodsThis paper describes the methodology of the CIRC trial. ResultsUnlike previous trials the CIRC trial studies iA-CPR where emphasis is placed on reducing “hands-off” time. The trial has six unique features: (1) training of all EMS providers in a standardized deployment strategy that reduces hands-off time and continuous monitoring for protocol compliance. (2) A pre-trial simulation study of provider compliance with the trial protocol. (3) Three distinct study phases (in-field training, run-in, and statistical inclusion) to minimize the Hawthorne effect and other biases. (4) Monitoring of the CPR process using either transthoracic impedance or accelerometer data. (5) Randomization at the subject level after the decision to resuscitate is made to reduce selection bias. (6) Use of the Group Sequential Double Triangular Test with sufficient power to determine superiority, inferiority, or equivalence. ConclusionThis unique, large, multicenter study comparing the effectiveness of iA-CPR to M-CPR will contribute to the science of the treatment of out-of-hospital cardiac arrest as well as to the design of future trials.

Design of the circulation improving resuscitation care (CIRC) trial: A new state of the art design for out-of-hospital cardiac arrest research

Purpose: Mechanical chest compression devices, such as the AutoPulse®, have been developed to overcome problems associated with manual CPR (M-CPR). Some animal and human studies have shown that AutoPulse CPR improves hemodynamic parameters over M-CPR. However, human studies conducted in the prehospital setting have generated conflicting results as to the AutoPulse's efficacy in improving survival. The Circulation Improving Resuscitation Care (CIRC) Trial was designed to evaluate the effectiveness of integrated AutoPulse-CPR (iA-CPR) in a randomized controlled trial that addresses methodological issues that may have influenced the results of previous studies. Methods: This paper describes the methodology of the CIRC trial. Results Unlike previous trials the CIRC trial studies iA-CPR where emphasis is placed on reducing “hands off” time, and subjects receive M-CPR until the device is applied. The trial has 6 unique features: (1) A standardized deployment strategy with training provided to all EMS providers and continuous monitoring of protocol compliance. (2) A simulation study conducted to document provider compliance with the trial protocol and quality of CPR before starting the statistical inclusion phase of the study. (3) Three distinct study phases (in-field training, run-in, and statistical inclusion) to minimize the Hawthorne effect and other biases. (4) Monitoring of the CPR process using transthoracic impedance data and/or accelerometer data. (5) Randomization at the patient level after the decision to resuscitate is made. (6) Group sequential double triangular test statistics with pre-planned interim analyses to ensure the study question is answered. Conclusion: In the design of the CIRC trial efforts have been made to employ a suitable methodology to test the effectiveness and safety of iA-CPR compared to M-CPR. This unique large multicenter study will contribute to the science of the treatment of out-of-hospital cardiac arrest as well as to the design of future trials.