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Background: NULL-PLEASE is a simple and accurate clinical scoring system developed in a Western cohort of patients with out-of-hospital cardiac arrest (OHCA). The need for blood test results limits its use in early stages of care. We adapted and validated the NULL-EASE score (without laboratory tests) in an independent, multiethnic Asian cohort of patients with out-of-hospital cardiac arrest., Methods and Results: Using the Singapore OHCA registry, we included consecutive adult patients with out-of-hospital cardiac arrest who survived to hospital admission between April 2010 to December 2020. In-hospital mortality was the primary outcome. Logistic regression analyses were performed with STATA MP v18. Of 3274 patients (median age 64, interquartile range 54-75; 67.9% male) included in the study, 2476 (75.6%) had in-hospital mortality. NULL-EASE score was significantly lower in survivors compared with nonsurvivors (median [inter quartile range] 3 [1-4] versus 6 [4-7]; P <0.001) and strongly predictive of mortality (area under receiver operating characteristic, 0.81 [95% CI, 0.79-0.83]). Patients with a score of ≥3 had higher odds of mortality (adjusted odds ratio, 8.11 [95% CI, 6.57-10.00]) when compared with those with lower scores, after adjusting for sex, residential arrest, diabetes, respiratory disease, and stroke. A cutoff value of ≥3 predicted mortality with 92.2% sensitivity, 84.1% positive predictive value, 46.1% specificity, and 65.5% negative predictive value. NULL-EASE score performed better in younger compared with older patients (area under receiver operating characteristic, 0.82 versus 0.77, P =0.008)., Conclusions: The NULL-EASE score has good discriminative performance (sensitivity and accuracy) in our multiethnic Asian cohort, but the cutoff of ≥3 falls short of the desired level of specificity for therapeutic decision-making.

Background: Extracorporeal cardiopulmonary resuscitation (ECPR) is an option for refractory cardiac arrest, and immediate initiation after indication is recommended. However, the practical goals of ECPR preparation (such as the door-to-needle time) remain unclear. This study aimed to elucidate the association between the door-to-needle time and neurological outcomes of out-of-hospital cardiac arrest., Methods and Results: This is a post hoc analysis of a nationwide multicenter study on out-of-hospital cardiac arrest treated with ECPR at 36 institutions between 2013 and 2018 (SAVE-J [Study of Advanced Cardiac Life Support for Ventricular Fibrillation with Extracorporeal Circulation in Japan] II study). Adult patients without hypothermia (≥32 °C) in whom circulation was not returned at ECPR initiation were included. The probability of favorable neurological function at 30 days (defined as Cerebral Performance Category ≤2) was estimated using a generalized estimating equations model, in which institutional, patient, and treatment characteristics were adjusted. Estimated probabilities were then calculated according to the door-to-needle time with 3-minute increments, and a clinical threshold was assumed. Among 1298 patients eligible for this study, 136 (10.6%) had favorable neurological function. The estimated probability of favorable outcomes was highest in patients with 1 to 3 minutes of door-to-needle time (12.9% [11.4%-14.3%]) and remained at 9% to 10% until 27 to 30 minutes. Then, the probability dropped gradually with each 3-minute delay. A 30-minute threshold was assumed, and shorter door-to-extracorporeal membrane oxygenation/low-flow time and fewer adverse events related to cannulation were observed in patients with door-to-needle time <30 minutes., Conclusions: The probability of favorable functions after out-of-hospital cardiac arrest decreased as the door-to-needle time for ECPR was prolonged, with a rapid decline after 27 to 30 minutes., Registration: URL: https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr&#95;view.cgi?recptno=R000041577; Unique identifier: UMIN000036490.

Background: Few prediction models for individuals with early-stage out-of-hospital cardiac arrest (OHCA) have undergone external validation. This study aimed to externally validate updated prediction models for OHCA outcomes using a large nationwide dataset., Methods and Results: We performed a secondary analysis of the JAAM-OHCA (Comprehensive Registry of In-Hospital Intensive Care for Out-of-Hospital Cardiac Arrest Survival and the Japanese Association for Acute Medicine Out-of-Hospital Cardiac Arrest) registry. Previously developed prediction models for patients with cardiac arrest who achieved the return of spontaneous circulation were updated. External validation was conducted using data from 56 institutions from the JAAM-OHCA registry. The primary outcome was a dichotomized 90-day cerebral performance category score. Two models were updated using the derivation set (n=3337). Model 1 included patient demographics, prehospital information, and the initial rhythm upon hospital admission; Model 2 included information obtained in the hospital immediately after the return of spontaneous circulation. In the validation set (n=4250), Models 1 and 2 exhibited a C-statistic of 0.945 (95% CI, 0.935-0.955) and 0.958 (95% CI, 0.951-0.960), respectively. Both models were well-calibrated to the observed outcomes. The decision curve analysis showed that Model 2 demonstrated higher net benefits at all risk thresholds than Model 1. A web-based calculator was developed to estimate the probability of poor outcomes (https://pcas-prediction.shinyapps.io/90d&#95;lasso/)., Conclusions: The updated models offer valuable information to medical professionals in the prediction of long-term neurological outcomes for patients with OHCA, potentially playing a vital role in clinical decision-making processes.

Background: Out-of-hospital cardiac arrest survival rates have improved over time. This study established whether improvements were similar for women and men, and to what extent resuscitation characteristics or in-hospital procedures contributed to sex differences in temporal trends., Methods and Results: This retrospective cohort study included 3386 women and 8564 men from North Holland, the Netherlands, who experienced an out-of-hospital cardiac arrest from a cardiac cause in 2005 to 2017. Yearly rates of 30-day survival and secondary outcomes were calculated. Sex differences in temporal trends were evaluated with age-adjusted Poisson regression analysis, including interaction for sex and out-of-hospital cardiac arrest year. Resuscitation characteristics and in-hospital procedures were added to the model, and a spline at 2013 was considered. During the study period, the average 30-day survival was 24.9% in men and 15.7% in women. The 30-day survival rate increased in men (20% to 27.2%; P <0.001) but not in women (15.0% to 11.6%; P =0.40). The increase in the 30-day survival rate was 3% higher per year in men than in women (rate ratio, 1.03 [95% CI, 1.00-1.05]), with a stronger difference after 2013. Men had a larger increase in survival rate to the hospital arrival than women in 2005 to 2013, and, after 2013, an advantage over women in survival rate after hospital arrival. The sex differences were partly explained by differing trends in shockable initial rhythm (eg, adjusted rate ratio, 1.01 [95% CI, 0.99-1.03] for 30-day survival) and provision of in-hospital procedures., Conclusions: Changes in rates of 30-day survival, survival to hospital arrival, and, after 2013, survival from hospital arrival to 30 days were more beneficial in men than women. The differences in trends were partly explained by shockable initial rhythm and in-hospital procedures.

Background: International consensus on cardiopulmonary resuscitation (CPR) and emergency cardiovascular care science and treatment recommendations (CoSTR) have reported updates on CPR maneuvers every 5 years since 2000. However, few national population-based studies have investigated the comprehensive effectiveness of those updates for out-of-hospital cardiac arrest due to shockable rhythms. The primary objective of the present study was to determine whether CPR based on CoSTR 2005 or 2010 was associated with improved outcomes in Japan, as compared with CPR based on Guidelines 2000., Methods and Results: From the All-Japan Utstein Registry between 2005 and 2015, we included 73 578 adults who had shockable out-of-hospital cardiac arrest witnessed by bystanders or emergency medical service responders. The study outcomes over an 11-year period were compared between 2005 of the Guidelines 2000 era, from 2006 to 2010 of the CoSTR 2005 era, and from 2011 to 2015 of the CoSTR 2010 era. In the bystander-witnessed group, the adjusted odds ratios for favorable neurological outcomes at 30 days after out-of-hospital cardiac arrest by enrollment year increased year by year (1.19 in 2006, and 3.01 in 2015). Similar results were seen in the emergency medical service responder-witnessed group and several subgroups., Conclusions: Compared with CPR maneuvers for shockable out-of-hospital cardiac arrest recommended in the Guidelines 2000, CPR maneuver updates in CoSTR 2005 and 2010 were associated with improved neurologically intact survival year by year in Japan. Increased public awareness and greater dissemination of basic life support may be responsible for the observed improvement in outcomes., Registration: URL: https://www.umin.ac.jp/ctr/; Unique identifier: 000009918.

Background: Given increases in drug overdose-associated mortality, there is interest in better understanding of drug overdose out-of-hospital cardiac arrest (OHCA). A comparison between overdose-attributable OHCA and nonoverdose-attributable OHCA will inform public health measures., Methods and Results: We analyzed data from 2017 to 2021 in the Cardiac Arrest Registry to Enhance Survival (CARES), comparing overdose-attributable OHCA (OD-OHCA) with OHCA from other nontraumatic causes (non-OD-OHCA). Arrests involving patients <18 years, health care facility residents, patients with cancer diagnoses, and patients with select missing data were excluded. Our main outcome of interest was survival with good neurological outcome, defined as Cerebral Performance Category score 1 or 2. From a data set with 537 100 entries, 29 500 OD-OHCA cases and 338 073 non-OD-OHCA cases met inclusion criteria. OD-OHCA cases involved younger patients with fewer comorbidities, were less likely to be witnessed, and less likely to present with a shockable rhythm. Unadjusted survival to hospital discharge with Cerebral Performance Category score =1 or 2 was significantly higher in the OD-OHCA cohort (OD: 15.2% versus non-OD: 6.9%). Adjusted results showed comparable survival with Cerebral Performance Category score =1 or 2 when the first monitored arrest rhythm was shockable (OD: 28.9% versus non-OD: 23.5%, P =0.087) but significantly higher survival rates with Cerebral Performance Category score =1 or 2 for OD-OHCA when the first monitored arrest rhythm was nonshockable (OD: 9.6% versus non-OD: 3.1%, P <0.001)., Conclusions: Among patients presenting with nonshockable rhythms, OD-OHCA is associated with significantly better outcomes. Further research should explore cardiac arrest causes, and public health efforts should attempt to reduce the burden from drug overdoses.

Background: Public access defibrillation (PAD) programs have been implemented globally over the past decade. Although PAD can substantially increase the survival of cardiac arrest, PAD use remains low. This study aimed to evaluate whether drawing upon the successful experiences of dispatcher-assisted cardiopulmonary resuscitation programs would increase the use of PAD in dispatcher-assisted PAD programs., Methods and Results: This study using a before-and-after design was conducted in Taoyuan City using a local out-of-hospital cardiac arrest registry system and data of dispatcher performance derived from audio recordings. The primary outcomes were the rate of bystander PAD use, sustained return of spontaneous circulation, survival to discharge, and favorable neurological outcomes. The secondary outcomes were the performance of dispatchers in terms of PAD instruction and dispatcher-assisted cardiopulmonary resuscitation administration, the time interval indicators of dispatcher-assisted cardiopulmonary resuscitation. A total of 1159 patients were included and divided into 2 groups: the before-run-in group (502 patients) and the after-run-in group (657 patients). No significant difference was observed between the 2 groups in terms of baseline characteristics. The rate of PAD use in the after-run-in group significantly increased from 5.0% to 8.7% ( P =0.015). The rate of favorable neurological outcomes increased from 4.4% to 5.9%, which was not a statistically significant difference. Compared with the before-run-in group, the rate of successful automated external defibrillator acquisition was 13.5% in the after-run-in group ( P <0.001)., Conclusions: Implementing a dispatcher-assisted PAD protocol in a municipality setting significantly increased bystander PAD use without affecting dispatcher performance in out-of-hospital cardiac arrest recognition, cardiopulmonary resuscitation instruction, or dispatcher-assisted cardiopulmonary resuscitation time indicators.

Background: Telecommunicator CPR (T-CPR), whereby emergency dispatch facilitates cardiac arrest recognition and coaches CPR over the telephone, is an important strategy to increase early recognition and bystander CPR in adult out-of-hospital cardiac arrest (OHCA). Little is known about this treatment strategy in the pediatric population. We investigated the role of T-CPR and related performance among pediatric OHCA., Methods and Results: This study was a retrospective cohort investigation of OHCA among individuals <18 years in King County, Washington, from April 1, 2013, to December 31, 2019. We reviewed the 911 audio recordings to determine if and how bystander CPR was delivered (unassisted or T-CPR), key time intervals in recognition of arrest, and key components of T-CPR delivery. Of the 185 eligible pediatric OHCAs, 23% (n=43) had bystander CPR initiated unassisted, 59% (n=109) required T-CPR, and 18% (n=33) did not receive CPR before emergency medical services arrival. Among all cases, cardiac arrest was recognized by the telecommunicator in 89% (n=165). Among those receiving T-CPR, the median (interquartile range) interval from start of call to OHCA recognition was 59 seconds (38-87) and first CPR intervention was 115 seconds (94-162). When stratified by age (≤8 versus >8), the older age group was less likely to receive CPR before emergency medical services arrival (88% versus 69%, P =0.002). For those receiving T-CPR, bystanders spent a median of 207 seconds (133-270) performing CPR. The median compression rate was 93 per minute (82-107) among those receiving T-CPR., Conclusions: T-CPR is an important strategy to increase early recognition and early CPR among pediatric OHCA.

Background: Risk stratification is important in patients with post-cardiac arrest syndrome. The Post-Cardiac Arrest Syndrome for Therapeutic Hypothermia (CAST) and revised CAST (rCAST) scores have been well validated for predicting neurological outcomes, particularly for conventionally resuscitated patients with post-cardiac arrest syndrome. However, no studies have evaluated patients undergoing extracorporeal cardiopulmonary resuscitation., Methods and Results: Adult patients with out-of-hospital cardiac arrest who underwent extracorporeal cardiopulmonary resuscitation were analyzed in this retrospective observational multicenter cohort study. We validated the accuracy of the CAST/rCAST scores for predicting neurological outcomes at 30 days. Moreover, we compared the predictive performance of these scores with the TiPS65 risk score derived from patients with out-of-hospital cardiac arrest who were resuscitated using extracorporeal cardiopulmonary resuscitation. A total of 1135 patients were analyzed. The proportion of patients with favorable neurological outcomes was 16.6%. In the external validation, the area under the receiver operating characteristic curve of the CAST score was significantly higher than that of the rCAST score (area under the receiver operating characteristic curve 0.677 versus 0.603; P <0.001), but there was no significant difference with that of the TiPS65 score (versus 0.633; P =0.154). Both CAST/rCAST risk scores showed good calibration (Hosmer-Lemeshow test: P =0.726 and 0.674), and the CAST score showed significantly better predictability in net reclassification compared with the rCAST ( P <0.001) and TiPS65 scores ( P =0.001)., Conclusions: The prognostic accuracy of the CAST score was significantly better than that of other risk scores in net reclassification. The CAST score may help to predict neurological outcomes in patients with out-of-hospital cardiac arrest who undergo extracorporeal cardiopulmonary resuscitation. However, the predictive value of the CAST score was not sufficiently high for clinical application., Registration: URL: https://center6.umin.ac.jp/cgi-open-bin/ctr&#95;e/ctr&#95;view.cgi?recptno=R000041577; Unique identifier: UMIN000036490.

Background High-quality cardiopulmonary resuscitation (CPR) is associated with improved survival from out-of-hospital cardiac arrest and includes chest compression depth, chest compression rate, and chest compression fraction within international guideline recommendations. Previous studies have demonstrated divergent results of real-time feedback on CPR performance and patient outcomes. This study investigated the association between emergency medical service CPR quality and real-time CPR feedback for out-of-hospital cardiac arrest. Methods and Results This study collected out-of-hospital cardiac arrest data within the Capital Region of Denmark and compared CPR quality delivered by ambulance personnel. Data were collected in 2 consecutive phases from October 2018 to February 2020. Median chest compression depth was 6.0 cm (no feedback) and 5.9 cm (real-time feedback) ( P =0.852). Corresponding proportion of guideline-compliant chest compressions for depth was 16.6% and 28.7%, respectively ( P <0.001). Median chest compression rate per minute was 111 and 109 ( P <0.001), respectively. Corresponding guideline adherence proportion for compression rate was 65.4% compared with 80.4% ( P <0.001), respectively. Chest compression fraction was 78.9% compared with 81.9% ( P <0.001), respectively. The combination of guideline-compliant chest compression depth and chest compression rate simultaneously was 8.5% (no feedback) versus 18.8% (feedback) ( P <0.001). Improvements were not significant for return of spontaneous circulation (odds ratio [OR], 1.08 [95% CI, 0.84-1.39]), sustained return of spontaneous circulation (OR, 1.00 [95% CI, 0.77-1.31]), or survival to hospital discharge (OR, 0.91 [95% CI, 0.64-1.30]). Conclusions Real-time feedback was associated with improved guideline compliance for chest compression depth, rate, and fraction but not return of spontaneous circulation, sustained return of spontaneous circulation, or survival to hospital discharge. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT04152252.

Background Disparities in bystander cardiopulmonary resuscitation (CPR) and survival have been reported for Black and Hispanic individuals with out-of-hospital cardiac arrest (OHCA). Whether Asian individuals have lower rates of bystander CPR and survival for OHCA, as compared with White individuals, remains unknown. Methods and Results Within the US-based CARES (Cardiac Arrest Registry to Enhance Survival), we identified 278 989 OHCAs in Asian and White individuals during 2013 to 2021. Using hierarchical Poisson logistic regression with emergency medical service agency modeled as a random effect and patient and OHCA characteristics as fixed effects, we compared rates of bystander CPR, survival to discharge, and favorable neurological survival between Asian and White individuals with OHCA. Overall, 14 835 (5.3%) OHCAs occurred in Asian individuals. Compared with White individuals with OHCA, Asian individuals were older (67.0±17.6 versus 62.8±16.9 years) and were less likely to have drug overdose as the cause of OHCA (1.3% versus 6.6%) and a shockable arrest rhythm (19.2% versus 22.4%). Layperson bystander CPR rates were similar between Asian and White individuals (42.6% versus 42.1%; adjusted relative risk for Asian individuals, 0.99 [95% CI, 0.97-1.02]; P =0.69). However, rates of survival to discharge were lower in Asian individuals with OHCA (8.2% versus 10.3%; adjusted relative risk 0.92 [0.86-0.98] P =0.006). Similarly, the rate of favorable neurological survival was lower for Asian individuals (6.5% versus 8.7%; adjusted relative risk, 0.85 [0.79-0.91]; P <0.001). Conclusions Despite similar rates of bystander CPR, Asian individuals with OHCA have lower survival rates than White individuals with OHCA. The reasons for the lower survival rate deserve further study to determine whether there are disparities in resuscitation care between Asian and White individuals with OHCA.

Background Once the return of spontaneous circulation after out-of-hospital cardiac arrest is achieved, a 12-lead ECG is strongly recommended to identify candidates for urgent coronary angiography. ECG has no apparent role in mortality risk stratification. We aimed to assess whether ECG features could be associated with 30-day survival in patients with out-of-hospital cardiac arrest. Methods and Results All the post-return of spontaneous circulation ECGs from January 2015 to December 2018 in 3 European centers (Pavia, Lugano, and Vienna) were collected. Prehospital data were collected according to the Utstein style. A total of 370 ECGs were collected: 287 men (77.6%) with a median age of 62 years (interquartile range, 53-70 years). After correction for the return of spontaneous circulation-to-ECG time, age >62 years (hazard ratio [HR], 1.78 [95% CI, 1.21-2.61]; P =0.003), female sex (HR, 1.5 [95% CI, 1.05-2.13]; P =0.025), QRS wider than 120 ms (HR, 1.64 [95% CI, 1.43-1.87]; P <0.001), the presence of a Brugada pattern (HR, 1.49 [95% CI, 1.39-1.59]; P <0.001), and the presence of ST-segment elevation in >1 segment (HR, 1.75 [95% CI, 1.59-1.93]; P <0.001) were independently associated with 30-day mortality. A score ranging from 0 to 26 was created, and by dividing the population into 3 tertiles, 3 classes of risk were found with significantly different survival rate at 30 days (score 0-4, 73%; score 5-7, 66%; score 8-26, 45%). Conclusions The post-return of spontaneous circulation ECG can identify patients who are at high risk of mortality after out-of-hospital cardiac arrest earlier than other forms of prognostication. This provides important risk stratification possibilities in postcardiac arrest care that could help to direct treatments and improve outcomes in patients with out-of-hospital cardiac arrest.

Background Of the more than 250 000 emergency medical services-treated out-of-hospital cardiac arrests that occur each year in the United States, only about 8% survive to hospital discharge with good neurologic function. Treatment for out-of-hospital cardiac arrest involves a system of care that includes complex interactions among multiple stakeholders. Understanding the factors inhibiting optimal care is fundamental to improving outcomes. Methods and Results We conducted group interviews with emergency responders including 911 telecommunicators, law enforcement officers, firefighters, and transporting emergency medical services personnel (ie, emergency medical technicians and paramedics) who responded to the same out-of-hospital cardiac arrest incident. We used the American Heart Association System of Care as the framework for our analysis to identify themes and their contributory factors from these interviews. We identified 5 themes under the structure domain, which included workload, equipment, prehospital communication structure, education and competency, and patient attitudes. In the process domain, 5 themes were identified focusing on preparedness, field response and access to patient, on-scene logistics, background information acquisition, and clinical interventions. We identified 3 system themes including emergency responder culture; community support, education, and engagement; and stakeholder relationships. Three continuous quality improvement themes were identified, which included feedback provision, change management, and documentation. Conclusions We identified structure, process, system, and continuous quality improvement themes that may be leveraged to improve outcomes for out-of-hospital cardiac arrest. Interventions or programs amenable to rapid implementation include improving prearrival communication between agencies, appointing patient care and logistical leadership on-scene, interstakeholder team training, and providing more standardized feedback to all responder groups.

Background Diagnosis of shockable rhythms leading to defibrillation remains integral to improving out-of-hospital cardiac arrest outcomes. New machine learning techniques have emerged to diagnose arrhythmias on ECGs. In out-of-hospital cardiac arrest, an algorithm within an automated external defibrillator is the major determinant to deliver defibrillation. This study developed and validated the performance of a convolution neural network (CNN) to diagnose shockable arrhythmias within a novel, miniaturized automated external defibrillator. Methods and Results There were 26 464 single-lead ECGs that comprised the study data set. ECGs of 7-s duration were retrospectively adjudicated by 3 physician readers (N=18 total readers). After exclusions (N=1582), ECGs were divided into training (N=23 156), validation (N=721), and test data sets (N=1005). CNN performance to diagnose shockable and nonshockable rhythms was reported with area under the receiver operating characteristic curve analysis, F1, and sensitivity and specificity calculations. The duration for the CNN to output was reported with the algorithm running within the automated external defibrillator. Internal and external validation analyses included CNN performance among arrhythmias, often mistaken for shockable rhythms, and performance among ECGs modified with noise to mimic artifacts. The CNN algorithm achieved an area under the receiver operating characteristic curve of 0.995 (95% CI, 0.990-1.0), sensitivity of 98%, and specificity of 100% to diagnose shockable rhythms. The F1 scores were 0.990 and 0.995 for shockable and nonshockable rhythms, respectively. After input of a 7-s ECG, the CNN generated an output in 383±29 ms (total time of 7.383 s). The CNN outperformed adjudicators in classifying atrial arrhythmias as nonshockable (specificity of 99.3%-98.1%) and was robust against noise artifacts (area under the receiver operating characteristic curve range, 0.871-0.999). Conclusions We demonstrate high diagnostic performance of a CNN algorithm for shockable and nonshockable rhythm arrhythmia classifications within a digitally connected automated external defibrillator. Registration URL: https://clinicaltrials.gov/ct2/show/NCT03662802; Unique identifier: NCT03662802.

Background Predicting a spontaneous rhythm change from nonshockable to shockable before hospital arrival in patients with out-of-hospital cardiac arrest can help emergency medical services develop better strategies for prehospital treatment. The aim of this study was to identify predictors of spontaneous rhythm change before hospital arrival in patients with out-of-hospital cardiac arrest and develop a predictive scoring system. Methods and Results We retrospectively reviewed data of eligible patients with out-of-hospital cardiac arrest with an initial nonshockable rhythm registered in a nationwide registry between June 2014 and December 2017. We performed a multivariable analysis using a Cox proportional hazards model to identify predictors of a spontaneous rhythm change, and a ridge regression model for predicting it. The data of 25 804 patients were analyzed (derivation cohort, n=17 743; validation cohort, n=8061). The rhythm change event rate was 4.1% (724/17 743) in the derivation cohort, and 4.0% (326/8061) in the validation cohorts. Age, sex, presence of a witness, initial rhythm, chest compression by a bystander, shock with an automated external defibrillator by a bystander, and cause of the cardiac arrest were all found to be independently associated with spontaneous rhythm change before hospital arrival. Based on this finding, we developed and validated the Rhythm Change Before Hospital Arrival for Nonshockable score. The Harrell's concordance index values of the score were 0.71 and 0.67 in the internal and external validations, respectively. Conclusions Seven factors were identified as predictors of a spontaneous rhythm change from nonshockable to shockable before hospital arrival. We developed and validated a score to predict rhythm change before hospital arrival.

Background The effects of amiodarone and lidocaine on the return of spontaneous circulation (ROSC) in relation to time to treatment in patients with out-of-hospital cardiac arrest is not known. We conducted a post hoc analysis of the ROC ALPS (Resuscitation Outcomes Consortium Amiodarone, Lidocaine, Placebo) randomized controlled trial examining the association of time to treatment (drug or placebo) with ROSC at hospital arrival. Methods and Results In the trial, adults with nontraumatic out-of-hospital cardiac arrest with initial refractory ventricular fibrillation or pulseless ventricular tachycardia after at least 1 defibrillation were randomly assigned to receive amiodarone, lidocaine, or placebo. We used logistic regression to examine the association of time to treatment (911 call to study drug administration) with ROSC. An interaction term between treatment and time to treatment was included to determine the potential effect of time on treatment effects. Overall, 1112 (36.7%) patients had ROSC at hospital arrival (350 in the amiodarone arm, 396 in the lidocaine arm, and 366 in the placebo arm). The proportion of patients who had ROSC decreased as time to drug administration increased, in patients treated with amiodarone (odds ratio, 0.92; 95% CI, 0.90-0.94 per minute increase), lidocaine (odds ratio, 0.95; 95% CI, 0.93-0.96), and placebo (odds ratio, 0.95; 95% CI, 0.93-0.96). With shorter times to drug administration, the proportion with ROSC was higher in amiodarone versus placebo recipients. Conclusions The probability of ROSC decreased as time to drug administration increased. The effect of amiodarone but not lidocaine to restore ROSC declined with longer times to drug administration, potentially attributable to its adverse hemodynamic effects.

Background Treatment with an automated external defibrillator (AED) improves outcome in out-of-hospital cardiac arrest (OHCA). Audiovisual feedback from an AED may assist bystanders achieve higher quality cardiopulmonary resuscitation. However, the association between audiovisual feedback and clinical outcomes is not well assessed in real-life OHCA. The aim of this study was to assess the association between audiovisual feedback from an AED used in bystander resuscitation with rates of return of spontaneous circulation (ROSC) and 30-day survival in a real-life cohort of patients with OHCA. Methods and Results We included 325 patients treated with bystander AED use before arrival of emergency medical services during 2016 to 2019 from the Capital Region of Denmark. Patients were divided into a "feedback" and a "nonfeedback" group, depending on presence of audiovisual feedback from the AED. Audiovisual feedback was defined as voice prompts with continuous feedback to ongoing resuscitation. Rates of ROSC upon hospital admission and 30-day survival were assessed, and univariate and multivariable models were applied to decide the association to audiovisual feedback. Multivariable models were adjusted for sex, age, primary heart rhythm, and location of OHCA. A total of 155 (48%) patients had a bystander AED applied with audiovisual feedback and 170 (52%) without audiovisual feedback. A lower rate of ROSC was found in the feedback group compared with the nonfeedback group (33% [n=51] versus 45% [n=76]; P =0.03). No association was observed between AV feedback and 30-day survival (feedback=27% [n=42] and nonfeedback=31% [n=53]; P =0.49). In the unadjusted logistic regression model, audiovisual feedback was associated with a decreased chance of ROSC (odds ratio, 0.61; 95% CI, 0.38-0.95; P =0.03), which remained significant after adjusted analysis (odds ratio, 0.53; 95% CI, 0.29-0.97; P =0.04), whereas we found no significant association between audiovisual feedback and 30-day survival in the unadjusted and adjusted analyses. Conclusions Audiovisual feedback from an AED used by bystanders was associated with a lower chance of ROSC at hospital admission, but we found no significant difference in 30-day survival. Focus on early and correct bystander cardiopulmonary resuscitation and AED use remain key for OHCA survival.

Background We aim to examine diurnal and weekday variations in citizen responder availability and intervention at out-of-hospital cardiac arrest (OHCA) resuscitation. Methods and Results We included confirmed OHCAs where citizen responders were activated by a smartphone application in the Capital Region of Denmark between September 1, 2017 and August 31, 2018. OHCAs were analyzed by time of day (daytime: 07:00 am-03:59 pm, evening: 4:00-11:59 pm, and nighttime: 12:00-06:59 am) and day of week (Monday-Friday or Saturday-Sunday/public holidays). We included 438 OHCAs where 6836 citizen responders were activated. More citizen responders accepted alarms in the evening (mean 4.8 [95% CI, 4.4-5.3]) compared with daytime (3.7 [95% CI, 3.4-4.4]) and nighttime (1.8 [95% CI, 1.5-2.2]) ( P <0.001), and more accepted alarms during weekends (4.3 [95% CI, 3.8-4.9]) compared with weekdays (3.4 [95% CI, 3.2-3.7]) ( P <0.001). Proportion of OHCAs where at least 1 citizen responder arrived before Emergency Medical Services were significantly different between day (42.9%), evening (50.3%), and night (26.1%) ( P <0.001), and between weekdays (37.2%) and weekends (53.5%) ( P =0.002). When responders arrived before Emergency Medical Services, there was no difference of bystander cardiopulmonary resuscitation or defibrillation between daytime, evening, and nighttime ( P =0.75 and P =0.22, respectively) or between weekend and weekdays ( P =0.29 and P =0.12, respectively). Conclusions Citizen responders were more likely to accept OHCA alarms during evening and weekends, with the highest proportion of responders arriving before Emergency Medical Services in the evening. However, there was no significant difference in delivering cardiopulmonary resuscitation or early defibrillation among cases where citizen responders arrived before Emergency Medical Services. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03835403.

Background The role of cardiac arrest centers (CACs) in out-of-hospital cardiac arrest care systems is continuously evolving. Interpretation of existing literature is limited by heterogeneity in CAC characteristics and types of patients transported to CACs. This study assesses the impact of CACs on survival in out-of-hospital cardiac arrest according to varying definitions of CAC and prespecified subgroups. Methods and Results Electronic databases were searched from inception to March 9, 2021 for relevant studies. Centers were considered CACs if self-declared by study authors and capable of relevant interventions. Main outcomes were survival and neurologically favorable survival at hospital discharge or 30 days. Meta-analyses were performed for adjusted odds ratio (aOR) and crude odds ratios. Thirty-six studies were analyzed. Survival with favorable neurological outcome significantly improved with treatment at CACs (aOR, 1.85 [95% CI, 1.52-2.26]), even when including high-volume centers (aOR, 1.50 [95% CI, 1.18-1.91]) or including improved-care centers (aOR, 2.13 [95% CI, 1.75-2.59]) as CACs. Survival significantly increased with treatment at CACs (aOR, 1.92 [95% CI, 1.59-2.32]), even when including high-volume centers (aOR, 1.74 [95% CI, 1.38-2.18]) or when including improved-care centers (aOR, 1.97 [95% CI, 1.71-2.26]) as CACs. The treatment effect was more pronounced among patients with shockable rhythm ( P =0.006) and without prehospital return of spontaneous circulation ( P =0.005). Conclusions were robust to sensitivity analyses, with no publication bias detected. Conclusions Care at CACs was associated with improved survival and neurological outcomes for patients with nontraumatic out-of-hospital cardiac arrest regardless of varying CAC definitions. Patients with shockable rhythms and those without prehospital return of spontaneous circulation benefited more from CACs. Evidence for bypassing hospitals or interhospital transfer remains inconclusive.

Background To compare the 2-finger and 2-thumb chest compression techniques on infant manikins in an out-of-hospital setting regarding efficiency of compressions, ventilation, and rescuer pain and fatigue. Methods and Results In a randomized crossover design, 78 medical students performed 2 minutes of cardiopulmonary resuscitation with mouth-to-nose ventilation at a 30:2 rate on a Resusci Baby QCPR infant manikin (Laerdal, Stavanger, Norway), using a barrier device and the 2-finger and 2-thumb compression techniques. Frequency and depth of chest compressions, proper hand position, complete chest recoil at each compression, hands-off time, tidal volume, and number of ventilations were evaluated through manikin-embedded SkillReporting software. After the interventions, standard Likert questionnaires and analog scales for pain and fatigue were applied. The variables were compared by a paired t -test or Wilcoxon test as suitable. Seventy-eight students participated in the study and performed 156 complete interventions. The 2-thumb technique resulted in a greater depth of chest compressions (42 versus 39.7 mm; P <0.01), and a higher percentage of chest compressions with adequate depth (89.5% versus 77%; P <0.01). There were no differences in ventilatory parameters or hands-off time between techniques. Pain and fatigue scores were higher for the 2-finger technique (5.2 versus 1.8 and 3.8 versus 2.6, respectively; P <0.01). Conclusions In a simulation of out-of-hospital, single-rescuer infant cardiopulmonary resuscitation, the 2-thumb technique achieves better quality of chest compressions without interfering with ventilation and causes less rescuer pain and fatigue.

Background The mechanism by which bystander cardiopulmonary resuscitation (CPR) improves survival following out-of-hospital cardiac arrest is unclear. We hypothesized that ventricular fibrillation (VF) waveform measures, as surrogates of myocardial physiology, mediate the relationship between bystander CPR and survival. Methods and Results We performed a retrospective cohort study of adult, bystander-witnessed patients with out-of-hospital cardiac arrest with an initial rhythm of VF who were treated by a metropolitan emergency medical services system from 2005 to 2018. Patient, resuscitation, and outcome variables were extracted from emergency medical services and hospital records. A total of 3 VF waveform measures (amplitude spectrum area, peak frequency, and median peak amplitude) were computed from a 3-second ECG segment before the initial shock. Multivariable logistic regression estimated the association between bystander CPR and survival to hospital discharge adjusted for Utstein elements. Causal mediation analysis quantified the proportion of survival benefit that was mediated by each VF waveform measure. Of 1069 patients, survival to hospital discharge was significantly higher among the 814 patients who received bystander CPR than those who did not (0.52 versus 0.43, respectively; P <0.01). The multivariable-adjusted odds ratio for bystander CPR and survival was 1.6 (95% CI, 1.2, 2.1), and each VF waveform measure attenuated this association. Depending on the specific waveform measure, the proportion of mediation varied: 53% for amplitude spectrum area, 31% for peak frequency, and 29% for median peak amplitude. Conclusions Bystander CPR correlated with more robust initial VF waveform measures, which in turn mediated up to one-half of the survival benefit associated with bystander CPR. These results provide insight into the biological mechanism of bystander CPR in VF out-of-hospital cardiac arrest.

Background Following the implementation of the HeartRescue project, with interventions in the community, emergency medical services, and hospitals to improve care and outcomes for out-of-hospital cardiac arrests (OHCA) in North Carolina, improved bystander and first responder treatments as well as survival were observed. This study aimed to determine whether these improvements were consistent across Black versus White individuals. Methods and Results Using the Cardiac Arrest Registry to Enhance Survival (CARES), we identified OHCA from 16 counties in North Carolina (population 3 million) from 2010 to 2014. Temporal changes in interventions and outcomes were assessed using multilevel multivariable logistic regression, adjusted for patient and socioeconomic neighborhood-level factors. Of 7091 patients with OHCA, 36.5% were Black and 63.5% were White. Black patients were younger, more females, had more unwitnessed arrests and non-shockable rhythm (Black: 81.0%; White: 75.4%). From 2010 to 2014, the adjusted probabilities of bystander cardiopulmonary resuscitation (CPR) went from 38.5% to 51.2% in White, P <0.001; and 36.9% to 45.6% in Black, P =0.002, and first-responder defibrillation went from 13.2% to 17.2% in White, P =0.002; and 14.7% to 17.3% in Black, P =0.16. From 2010 to 2014, survival to discharge only increased in White (8.0% to 11.4%, P =0.004; Black 8.9% to 9.5%, P =0.60), though, in shockable patients the probability of survival to discharge went from 24.8% to 34.6% in White, P =0.02; and 21.7% to 29.0% in Black, P =0. 10. Conclusions After the HeartRescue program, bystander CPR and first-responder defibrillation increased in both patient groups; however, survival only increased significantly for White patients.

Background The timing of advanced airway management (AAM) on patient outcomes after out-of-hospital cardiac arrest has not been fully investigated. We evaluated the association between the timing of prehospital AAM and 1-month survival. Methods and Results We conducted a secondary analysis of a prospective, nationwide, population-based out-of-hospital cardiac arrest registry in Japan. We included emergency medical services-treated adult (≥18 years) out-of-hospital cardiac arrests from 2014 through 2017, stratified into initial shockable or nonshockable rhythms. Patients who received AAM at any minute after emergency medical services-initiated cardiopulmonary resuscitation underwent risk-set matching with patients who were at risk of receiving AAM within the same minute using time-dependent propensity scores. Eleven thousand three hundred six patients with AAM in shockable and 163 796 with AAM in nonshockable cohorts, respectively, underwent risk-set matching. For shockable rhythms, the risk ratios (95% CIs) of AAM on 1-month survival were 1.01 (0.89-1.15) between 0 and 5 minutes, 1.06 (0.98-1.15) between 5 and 10 minutes, 0.99 (0.87-1.12) between 10 and 15 minutes, 0.74 (0.59-0.92) between 15 and 20 minutes, 0.61 (0.37-1.00) between 20 and 25 minutes, and 0.73 (0.26-2.07) between 25 and 30 minutes after emergency medical services-initiated cardiopulmonary resuscitation. For nonshockable rhythms, the risk ratios of AAM were 1.12 (1.00-1.27) between 0 and 5 minutes, 1.34 (1.25-1.44) between 5 and 10 minutes, 1.39 (1.26-1.54) between 10 and 15 minutes, 1.20 (0.99-1.45) between 15 and 20 minutes, 1.18 (0.80-1.73) between 20 and 25 minutes, 0.63 (0.29-1.38) between 25 and 30 minutes, and 0.44 (0.11-1.69) after 30 minutes. Conclusions In this observational study, the timing of AAM was not statistically associated with improved 1-month survival for shockable rhythms, but AAM within 15 minutes after emergency medical services-initiated cardiopulmonary resuscitation was associated with improved 1-month survival for nonshockable rhythms.

Background Little is known about the psychological risks of dispatched citizen responders who have participated in resuscitation attempts. Methods and Results A cross-sectional survey study was performed with 102 citizen responders who participated in a resuscitation attempt from July 23, 2018, to August 22, 2018, in the Capital Region of Denmark. Psychological distress, defined as symptoms of posttraumatic stress disorder, was assessed 3 weeks after the resuscitation attempt and measured with the Impact of Event Scale-Revised. Perceived stress was measured with the Perceived Stress Scale. Individual differences were assessed as the personality traits of agreeableness, conscientiousness, extraversion, neuroticism, and openness to experience with the Big Five Inventory, general self-efficacy, and coping mechanisms (Brief Coping Orientation to Problems Experienced Inventory). Associations between continuous variables were examined with the Pearson correlation. The associations between psychological distress levels and contextual factors and individual differences were analyzed in multivariable linear regression models to determine factors independently associated with psychological distress levels. The mean overall posttraumatic stress disorder score was 0.65 of 12; the mean perceived stress score was 7.61 of 40. The most common coping mechanisms were acceptance and emotional support. Low perceived stress was significantly associated with high general self-efficacy, and high perceived stress was significantly associated with high scores on neuroticism and openness to experience. Non-healthcare professionals were less likely to report symptoms of posttraumatic stress disorder. Conclusions Citizen responders who participated in resuscitation reported low levels of psychological distress. Individual differences were significantly associated with levels of psychological distress and should be considered when engaging citizen responders in resuscitation.

Background Public health emergencies may significantly impact emergency medical services responses to cardiovascular emergencies. We compared emergency medical services responses to out-of-hospital cardiac arrest (OHCA) and ST-segment‒elevation myocardial infarction (STEMI) during the 2020 COVID-19 pandemic to 2018 to 2019 and evaluated the impact of California's March 19, 2020 stay-at-home order. Methods and Results We conducted a population-based cross-sectional study using Los Angeles County emergency medical services registry data for adult patients with paramedic provider impression (PI) of OHCA or STEMI from February through May in 2018 to 2020. After March 19, 2020, weekly counts for PI-OHCA were higher (173 versus 135; incidence rate ratios, 1.28; 95% CI, 1.19‒1.37; P <0.001) while PI-STEMI were lower (57 versus 65; incidence rate ratios, 0.87; 95% CI, 0.78‒0.97; P =0.02) compared with 2018 and 2019. After adjusting for seasonal variation in PI-OHCA and decreased PI-STEMI, the increase in PI-OHCA observed after March 19, 2020 remained significant ( P =0.02). The proportion of PI-OHCA who received defibrillation (16% versus 23%; risk difference [RD], -6.91%; 95% CI, -9.55% to -4.26%; P <0.001) and had return of spontaneous circulation (17% versus 29%; RD, -11.98%; 95% CI, -14.76% to -9.18%; P <0.001) were lower after March 19 in 2020 compared with 2018 and 2019. There was also a significant increase in dead on arrival emergency medical services responses in 2020 compared with 2018 and 2019, starting around the time of the stay-at-home order ( P <0.001). Conclusions Paramedics in Los Angeles County, CA responded to increased PI-OHCA and decreased PI-STEMI following the stay-at-home order. The increased PI-OHCA was not fully explained by the reduction in PI-STEMI. Field defibrillation and return of spontaneous circulation were lower. It is critical that public health messaging stress that emergency care should not be delayed.

Background Studies have reported significant reduction in acute myocardial infarction-related hospitalizations during the coronavirus disease 2019 (COVID-19) pandemic. However, whether these trends are associated with increased incidence of out-of-hospital cardiac arrest (OHCA) in this population is unknown. Methods and Results Acute myocardial infarction hospitalizations with OHCA during the COVID-19 period (February 1-May 14, 2020) from the Myocardial Ischaemia National Audit Project and British Cardiovascular Intervention Society data sets were analyzed. Temporal trends were assessed using Poisson models with equivalent pre-COVID-19 period (February 1-May 14, 2019) as reference. Acute myocardial infarction hospitalizations during COVID-19 period were reduced by >50% (n=20 310 versus n=9325). OHCA was more prevalent during the COVID-19 period compared with the pre-COVID-19 period (5.6% versus 3.6%), with a 56% increase in the incidence of OHCA (incidence rate ratio, 1.56; 95% CI, 1.39-1.74). Patients experiencing OHCA during COVID-19 period were likely to be older, likely to be women, likely to be of Asian ethnicity, and more likely to present with ST-segment-elevation myocardial infarction. The overall rates of invasive coronary angiography (58.4% versus 71.6%; P <0.001) were significantly lower among the OHCA group during COVID-19 period with increased time to reperfusion (mean, 2.1 versus 1.1 hours; P =0.05) in those with ST-segment-elevation myocardial infarction. The adjusted in-hospital mortality probability increased from 27.7% in February 2020 to 35.8% in May 2020 in the COVID-19 group ( P <.001). Conclusions In this national cohort of hospitalized patients with acute myocardial infarction, we observed a significant increase in incidence of OHCA during COVID-19 period paralleled with reduced access to guideline-recommended care and increased in-hospital mortality.

Background Outcomes of patients from out-of-hospital cardiac arrest (OHCA) vary widely globally because of differences in prehospital systems of emergency care. National efforts had gone into improving OHCA outcomes in Singapore in recent years including community and prehospital initiatives. We aimed to document the impact of implementation of a national 5-year Plan for prehospital emergency care in Singapore on OHCA outcomes from 2011 to 2016. Methods and Results Prospective, population-based data of OHCA brought to Emergency Departments were obtained from the Pan-Asian Resuscitation Outcomes Study cohort. The primary outcome was Utstein (bystander witnessed, shockable rhythm) survival-to-discharge or 30-day postarrest. Mid-year population estimates were used to calculate age-standardized incidence. Multivariable logistic regression was performed to identify prehospital characteristics associated with survival-to-discharge across time. A total of 11 465 cases qualified for analysis. Age-standardized incidence increased from 26.1 per 100 000 in 2011 to 39.2 per 100 000 in 2016. From 2011 to 2016, Utstein survival rates nearly doubled from 11.6% to 23.1% ( P =0.006). Overall survival rates improved from 3.6% to 6.5% ( P <0.001). Bystander cardiopulmonary resuscitation rates more than doubled from 21.9% to 56.3% and bystander automated external defibrillation rates also increased from 1.8% to 4.6%. Age ≤65 years, nonresidential location, witnessed arrest, shockable rhythm, bystander automated external defibrillation, and year 2016 were independently associated with improved survival. Conclusions Implementation of a national prehospital strategy doubled OHCA survival in Singapore from 2011 to 2016, along with corresponding increases in bystander cardiopulmonary resuscitation and bystander automated external defibrillation. This can be an implementation model for other systems trying to improve OHCA outcomes.

Background Incidence and outcomes of out-of-hospital cardiac arrest (OHCA) vary between communities. We aimed to examine differences in patient characteristics, prehospital care, and outcomes in Singapore and Victoria. Methods and Results Using the prospective Singapore Pan-Asian Resuscitation Outcomes Study and Victorian Ambulance Cardiac Arrest Registry, we identified 11 061 and 32 003 emergency medical services-attended adult OHCAs between 2011 and 2016 respectively. Incidence and survival rates were directly age adjusted using the World Health Organization population. Survival was analyzed with logistic regression, with model selection via backward elimination. Of the 11 061 and 14 834 emergency medical services-treated OHCAs (overall mean age±SD 65.5±17.2; 67.4% males) in Singapore and Victoria respectively, 11 054 (99.9%) and 5595 (37.7%) were transported, and 440 (4.0%) and 2009 (13.6%) survived. Compared with Victoria, people with OHCA in Singapore were older (66.7±16.5 versus 64.6±17.7), had less shockable rhythms (17.7% versus 30.3%), and received less bystander cardiopulmonary resuscitation (45.7% versus 58.5%) and defibrillation (1.3% versus 2.5%) (all P <0.001). Age-adjusted OHCA incidence and survival rates increased in Singapore between 2011 and 2016 ( P <0.01 for trend), but remained stable, though higher, in Victoria. Likelihood of survival increased significantly ( P <0.001) with arrest in public locations (adjusted odds ratio [aOR] 1.81), witnessed arrest (aOR 2.14), bystander cardiopulmonary resuscitation (aOR 1.72), initial shockable rhythm (aOR 9.82), and bystander defibrillation (aOR 2.04) but decreased with increasing age (aOR 0.98) and emergency medical services response time (aOR 0.91). Conclusions Singapore reported increasing OHCA incidence and survival rates between 2011 and 2016, compared with stable, albeit higher, rates in Victoria. Survival differences might be related to different emergency medical services practices including patient selection for resuscitation and transport.

Background The ambulance response time in out-of-hospital cardiac arrest (OHCA) has doubled over the past 30 years in Sweden. At the same time, the chances of surviving an OHCA have increased substantially. A correct understanding of the effect of ambulance response time on the outcome after OHCA is fundamental for further advancement in cardiac arrest care. Methods and Results We used data from the SRCR (Swedish Registry of Cardiopulmonary Resuscitation) to determine the effect of ambulance response time on 30-day survival after OHCA. We included 20 420 cases of OHCA occurring in Sweden between 2008 and 2017. Survival to 30 days was our primary outcome. Stratification and multiple logistic regression were used to control for confounding variables. In a model adjusted for age, sex, calendar year, and place of collapse, survival to 30 days is presented for 4 different groups of emergency medical services (EMS)-crew response time: 0 to 6 minutes, 7 to 9 minutes, 10 to 15 minutes, and >15 minutes. Survival to 30 days after a witnessed OHCA decreased as ambulance response time increased. For EMS response times of >10 minutes, the overall survival among those receiving cardiopulmonary resuscitation before EMS arrival was slightly higher than survival for the sub-group of patients treated with compressions-only cardiopulmonary resuscitation. Conclusions Survival to 30 days after a witnessed OHCA decreases as ambulance response times increase. This correlation was seen independently of initial rhythm and whether cardiopulmonary resuscitation was performed before EMS-crew arrival. Shortening EMS response times is likely to be a fast and effective way of increasing survival in OHCA.

Background The use of adrenaline in out-of-hospital cardiac arrest (OHCA) patients is still controversial. This study aimed to determine the effects of early pre-hospital adrenaline administration in OHCA patients. Methods and Results PubMed, EMBASE, Google Scholar, and the Cochrane Library database were searched from study inception to February 2019 to identify studies that reported OHCA patients who received adrenaline. The primary outcome was survival to discharge, and the secondary outcomes were return of spontaneous circulation, favorable neurological outcome, and survival to hospital admission. A total of 574 392 patients were included from 24 studies. The use of early pre-hospital adrenaline administration in OHCA patients was associated with a significant increase in survival to discharge (risk ratio [RR], 1.62; 95% CI, 1.45-1.83; P <0.001) and return of spontaneous circulation (RR, 1.50; 95% CI, 1.36-1.67; P <0.001), as well as a favorable neurological outcome (RR, 2.09; 95% CI, 1.73-2.52; P <0.001). Patients with shockable rhythm cardiac arrest had a significantly higher rate of survival to discharge (RR, 5.86; 95% CI, 4.25-8.07; P <0.001) and more favorable neurological outcomes (RR, 5.10; 95% CI, 2.90-8.97; P <0.001) than non-shockable rhythm cardiac arrest patients. Conclusions Early pre-hospital administration of adrenaline to OHCA patients might increase the survival to discharge, return of spontaneous circulation, and favorable neurological outcomes. Registration URL: https://www.crd.york.ac.uk/PROSPERO; Unique identifier: CRD42019130542.

Background Should all out-of-hospital cardiac arrest (OHCA) patients be directly transported to cardiac arrest centers (CACs) remains under debate. Our study evaluated the impacts of different transport time and destination hospital on the outcomes of OHCA patients. Methods and Results Data were collected from 6655 OHCA patients recorded in the regional prospective OHCA registry database of Taoyuan City, Taiwan, between January 2012 and December 2016. Patients were matched on propensity score, which left 5156 patients, 2578 each in the CAC and non-CAC groups. Transport time was dichotomized into <8 and ≥8 minutes. The relations between the transport time to CACs and good neurological outcome at discharge and survival to discharge were investigated. Of the 5156 patients, 4215 (81.7%) presented with nonshockable rhythms and 941 (18.3%) presented with shockable rhythms. Regardless of transport time, transportation to a CAC increased the likelihoods of survival to discharge (<8 minutes: adjusted odds ratio [aOR], 1.95; 95% CI, 1.11-3.41; ≥8 minutes: aOR, 1.92; 95% CI, 1.25-2.94) and good neurological outcome at discharge (<8 minutes: aOR, 2.70; 95% CI, 1.40-5.22; ≥8 minutes: aOR, 2.20; 95% CI, 1.29-3.75) in OHCA patients with shockable rhythms but not in patients with nonshockable rhythms. Conclusions OHCA patients with shockable rhythms transported to CACs demonstrated higher probabilities of survival to discharge and a good neurological outcome at discharge. Direct ambulance delivery to CACs should thus be considered, particularly when OHCA patients present with shockable rhythms.

The use of extracorporeal cardiopulmonary resuscitation (E-CPR) for the treatment of patients with out-of-hospital cardiac arrest who do not respond to conventional cardiopulmonary resuscitation CPR) has increased significantly in the past 10 years, in response to case reports and observational studies reporting encouraging results. However, no randomized controlled trials comparing E-CPR with conventional CPR have been published to date. The evidence from systematic reviews of the available observational studies is conflicting. The inclusion criteria for published E-CPR studies are variable, but most commonly include witnessed arrest, immediate bystander CPR, an initial shockable rhythm, and an estimated time from CPR start to establishment of E-CPR (low-flow time) of <60 minutes. A shorter low-flow time has been consistently associated with improved survival. In an effort to reduce low-flow times, commencement of E-CPR in the prehospital setting has been reported and is currently under investigation. The provision of an E-CPR service, whether hospital based or prehospital, carries considerable cost and technical challenges. Despite increased adoption, many questions remain as to which patients will derive the most benefit from E-CPR, when and where to implement E-CPR, optimal post-arrest E-CPR care, and whether this complex invasive intervention is cost-effective. Results of ongoing trials are awaited to determine whether E-CPR improves survival when compared with conventional CPR.

Background The natural cycle of large-scale wildfires is accelerating, increasingly exposing both rural and populous urban areas to wildfire emissions. While respiratory health effects associated with wildfire smoke are well established, cardiovascular effects have been less clear. Methods and Results We examined the association between out-of-hospital cardiac arrest and wildfire smoke density (light, medium, heavy smoke) from the National Oceanic Atmospheric Association's Hazard Mapping System. Out-of-hospital cardiac arrest data were provided by the Cardiac Arrest Registry to Enhance Survival for 14 California counties, 2015-2017 (N=5336). We applied conditional logistic regression in a case-crossover design using control days from 1, 2, 3, and 4 weeks before case date, at lag days 0 to 3. We stratified by pathogenesis, sex, age (19-34, 35-64, and ≥65 years), and socioeconomic status (census tract percent below poverty). Out-of-hospital cardiac arrest risk increased in association with heavy smoke across multiple lag days, strongest on lag day 2 (odds ratio, 1.70; 95% CI, 1.18-2.13). Risk in the lower socioeconomic status strata was elevated on medium and heavy days, although not statistically significant. Higher socioeconomic status strata had elevated odds ratios with heavy smoke but null results with light and medium smoke. Both sexes and age groups 35 years and older were impacted on days with heavy smoke. Conclusions Out-of-hospital cardiac arrests increased with wildfire smoke exposure, and lower socioeconomic status appeared to increase the risk. The future trajectory of wildfire, along with increasing vulnerability of the aging population, underscores the importance of formulating public health and clinical strategies to protect those most vulnerable.

Extracorporeal cardiopulmonary resuscitation (ECPR) followed by targeted temperature management has been demonstrated to significantly improve the outcomes of out-of-hospital cardiac arrest (OHCA) in adult patients. Although recent narrative and systematic reviews on extracorporeal life support in the emergency department are available in the literature, they are focused on the efficacy of ECPR, and no comprehensively summarized review on ECPR for OHCA in adult patients is available. In this review, we aimed to clarify the prevalence, pathophysiology, predictors, management, and details of the complications of ECPR for OHCA, all of which have not been reviewed in previous literature, with the aim of facilitating understanding among acute care physicians. The leading countries in the field of ECPR are those in East Asia followed by those in Europe and the United States. ECPR may reduce the risks of reperfusion injury and deterioration to secondary brain injury. Unlike conventional cardiopulmonary resuscitation, however, no clear prognostic markers have been identified for ECPR for OHCA. Bleeding was identified as the most common complication of ECPR in patients with OHCA. Future studies should combine ECPR with intra-aortic balloon pump, extracorporeal membrane oxygenation flow, target blood pressure, and seizure management in ECPR.

Background Coronary artery disease is the primary etiology for sudden cardiac arrest in adults, but potential differences in the incidence and utility of invasive coronary testing between resuscitated men and women have not been extensively evaluated. Our aim was to characterize angiographic similarities and differences between men and women after cardiac arrest. Methods and Results Data from the International Cardiac Arrest Registry-Cardiology database included patients resuscitated from out-of-hospital cardiac arrest of presumed cardiac origin, admitted to 7 academic cardiology/resuscitation centers during 2006 to 2017. Demographics, clinical factors, and angiographic findings of subjects were evaluated in relationship to sex and multivariable logistic regression models created to predict both angiography and outcome. Among 966 subjects, including 277 (29%) women and 689 (71%) men, fewer women had prior coronary artery disease and more had prior congestive heart failure ( P =0.05). Women were less likely to have ST-segment-elevation myocardial infarction (32% versus 39%, P =0.04). Among those with ST-segment-elevation myocardial infarctions, identification and distribution of culprit arteries was similar between women and men, and there were no differences in treatment or outcome. In patients without ST-segment elevation post-arrest, women were overall less likely to undergo coronary angiography (51% versus 61%, P <0.02), have a culprit vessel identified (29% versus 45%, P =0.03), and had fewer culprits acutely occluded (17% versus 28%, P =0.03). Women were also less often re-vascularized (44% versus 52%, P <0.03). Conclusions Among cardiac arrest survivors, women are less likely to undergo angiography or percutaneous coronary intervention than men. Sex disparities for invasive therapies in post-cardiac arrest care need continued attention.

Background Interruptions in chest compressions contribute to poor outcomes in out-of-hospital cardiac arrest. The objective of this retrospective observational cohort study was to characterize the frequency, reasons, and duration of interruptions in chest compressions and to determine if interruptions changed over time. Methods and Results All out-of-hospital cardiac arrests treated by the Seattle Fire Department (Seattle, WA, United States) from 2007 to 2016 with capture of recordings from automated external defibrillators and manual defibrillators were included. Compression interruptions >1 second were classified into categories using audio recordings. Among the 3601 eligible out-of-hospital cardiac arrests, we analyzed 74 584 minutes, identifying 30 043 pauses that accounted for 6621 minutes (8.9% of total resuscitation duration). The median total interruption duration per case decreased from 115 seconds in 2007 to 72 seconds in 2016 ( P <0.0001). Median individual interruption duration decreased from 14 seconds in 2007 to 7 seconds in 2016 ( P <0.0001). Among interruptions >10 seconds, median interruption duration decreased from 20 seconds in 2007 to 16 seconds in 2016 ( P <0.0001). Cardiac rhythm analysis accounted for most compression interruptions. Manual ECG rhythm analysis and pulse checks accounted for 41.6% of all interruption time (median individual interruption, 8 seconds), automated external defibrillator rhythm analysis for 13.7% (median, 17 seconds), and manual rhythm analysis and shock delivery for 8.0% (median, 9 seconds). Conclusions Median duration of chest compression interruptions decreased by half from 2007 to 2016, indicating that care teams can significantly improve performance. Reducing compression interruptions is an evidence-based benchmark that provides a modifiable process quality improvement goal.

Background Targeted temperature management ( TTM ) is a recommended treatment modality to improve neurological outcomes in patients with out-of-hospital cardiac arrest. The impact of the duration from hospital admission to TTM initiation (door-to- TTM ; DTT ) on clinical outcomes has not been well elucidated. We hypothesized that shorter DTT initiation intervals would be associated with improved survival with favorable neurological outcome. Methods and Results We performed a post hoc analysis of nontraumatic paramedic-treated out-of-hospital cardiac arrests. The primary outcome was favorable neurological status at hospital discharge, with a secondary outcome of survival to discharge. We fit a logistic regression analysis to determine the association of early compared with delayed DTT , dichotomized by the median DTT duration, and outcomes. Of 3805 patients enrolled in the CCC (Continuous Chest Compressions) Trial in British Columbia, 570 were included in this analysis. There was substantial variation in DTT among patients receiving TTM . The median DTT duration was 122 minutes (interquartile range 35-218). Favorable neurological outcomes in the early and delayed DTT groups were 48% and 38%, respectively. Compared with delayed DTT (interquartile range 167-319 minutes), early DTT (interquartile range 20-81 minutes) was associated with survival (adjusted odds ratio 1.56, 95% CI 1.02-2.38) but not with favorable neurological outcomes (adjusted odds ratio 1.45, 95% CI , 0.94-2.22) at hospital discharge. Conclusions There was wide variability in the initiation of TTM among comatose out-of-hospital cardiac arrest survivors. Initiation of TTM within 122 minutes of hospital admission was associated with improved survival. These results support in-hospital efforts to achieve early DTT among out-of-hospital cardiac arrest patients admitted to the hospital.

Background: The response time of emergency medical services (EMS) is an important determinant of survival after out-of-hospital cardiac arrest. We sought to identify upper limits of EMS response times and bystander interventions associated with neurologically intact survival., Methods and Results: We analyzed the records of 553 426 patients with out-of-hospital cardiac arrest in a Japanese registry between 2010 and 2014. The primary study end point was 1-month neurologically intact survival (Cerebral Performance Category scale 1 or 2). Increased EMS response time was associated with significantly decreased adjusted odds of 1-month neurologically intact survival (adjusted odds ratio [aOR] for each 1-minute increase, 0.89; 95% confidence interval [CI], 0.89-0.90), although this relationship was modified by bystander interventions. The bystander interventions and the ranges of EMS response times that were associated with increased adjusted 1-month neurologically intact survival were as follows: bystander defibrillation, from ≤2 minutes (aOR, 3.10 [95% CI, 1.25-7.31]) to 13 minutes (aOR, 5.55 [95% CI, 2.66-11.2]); bystander conventional cardiopulmonary resuscitation, from 3 minutes (aOR 1.48 [95% CI, 1.02-2.12]) to 11 minutes (aOR 2.41 [95% CI, 1.61-3.56]); and bystander chest-compression-only cardiopulmonary resuscitation, from ≤2 minutes (aOR 1.57 [95% CI, 1.01-2.25]) to 11 minutes (aOR 1.92 [95% CI, 1.45-2.56]). However, the increase in neurologically intact survival of those receiving bystander interventions became statistically insignificant compared with no bystander interventions when the EMS response time was outside these ranges., Conclusions: The upper limits of the EMS response times associated with improved 1-month neurologically intact survival were 13 minutes when bystanders provided defibrillation (typically with cardiopulmonary resuscitation) and 11 minutes when bystanders provided cardiopulmonary resuscitation without defibrillation., (© 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Background: Mechanical cardiopulmonary resuscitation (mCPR) for patients with out-of-hospital cardiac arrest attending the emergency department has become more widespread in Japan. The objective of this study is to determine the association between the mCPR in the emergency department and clinical outcomes., Methods and Results: In a prospective, multicenter, observational study, adult patients with out-of-hospital cardiac arrest with sustained circulatory arrest on hospital arrival were identified. The primary outcome was survival to hospital discharge. The secondary outcomes included a return of spontaneous circulation and successful hospital admission. Multivariate analyses adjusted for potential confounders and within-institution clustering effects using a generalized estimation equation were used to analyze the association of the mCPR with outcomes. Between January 1, 2012 and March 31, 2013, 6537 patients with out-of-hospital cardiac arrest were eligible; this included 5619 patients (86.0%) in the manual CPR group and 918 patients (14.0%) in the mCPR group. Of those patients, 28.1% (1801/6419) showed return of spontaneous circulation in the emergency department, 20.4% (1175/5754) had hospital admission, 2.6% (168/6504) survived to hospital discharge, and 1.2% (75/6419) showed a favorable neurological outcome at 1 month after admission. Multivariate analyses revealed that mCPR was associated with a decreased likelihood of survival to hospital discharge (adjusted odds ratio, 0.40; 95% confidence interval, 0.20-0.78; P =0.005), return of spontaneous circulation (adjusted odds ratio, 0.71; 95% confidence interval, 0.53-0.94; P =0.018), and hospital admission (adjusted odds ratio, 0.57; 95% confidence interval, 0.40-0.80; P =0.001)., Conclusions: After accounting for potential confounders, the mCPR in the emergency department was associated with decreased likelihoods of good clinical outcomes after adult nontraumatic out-of-hospital cardiac arrest. Further studies are needed to clarify circumstances in which mCPR may benefit these patients., (© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Background: Patients with ST-elevation myocardial infarction (STEMI) with out-of-hospital cardiac arrest (OHCA) may benefit from direct transport to a percutaneous cardiac intervention (PCI) hospital but have previously been less likely to bypass local non-PCI hospitals to go to a PCI center., Methods and Results: We reported time trends in emergency medical service transport and care of patients with STEMI with and without OHCA included from 171 PCI-capable hospitals in 16 US regions with participation in the Mission: Lifeline STEMI Accelerator program between July 1, 2012, and March 31, 2014. Time trends by quarter were assessed using logistic regression with generalized estimating equations to account for hospital clustering. Of 13 189 emergency medical service-transported patients, 88.7% (N=11 703; 10.5% OHCA) were taken directly to PCI hospitals. Among 1486 transfer-in patients, 21.7% had OHCA. Direct transport to a PCI center for OHCA increased from 74.7% (July 1, 2012) to 83.6% (March 31, 2014) (odds ratio per quarter, 1.07; 95% confidence interval, 1.02-1.14), versus 89.0% to 91.0% for patients without OHCA (odds ratio, 1.03; 95% confidence interval, 0.99-1.07; interaction P =0.23). The proportion with prehospital ECGs increased for patients taken directly to PCI centers (53.9%-61.9% for those with OHCA versus 73.9%-81.9% for those without OHCA; interaction P =0.12). Of 997 patients with OHCA taken directly to PCI hospitals and treated with primary PCI, first medical contact-to-device times within the guideline-recommended goal of ≤90 minutes were met for 34.5% on July 1, 2012, versus 41.8% on March 31, 2014 (51.6% and 56.1%, respectively, for 9352 counterparts without OHCA; interaction P =0.72)., Conclusions: Direct transport to PCI hospitals increased for patients with STEMI with and without OHCA during the 2012 to 2014 Mission: Lifeline STEMI Accelerator program. Proportions with prehospital ECGs and timely reperfusion increased for patients taken directly to PCI hospitals., (© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Background: Dispatch of basic life support-trained first responders equipped with automated external defibrillators in addition to advanced life support-trained emergency medical services personnel in out-of-hospital cardiac arrest (OHCA) has, in some minor cohort studies, been associated with improved survival. The aim of this study was to evaluate the association between basic life support plus advanced life support response and survival in OHCA at a national level., Methods and Results: This prospective cohort study was conducted from January 1, 2012, to December 31, 2014. People who experienced OHCA in 9 Swedish counties covered by basic life support plus advanced life support response were compared with a propensity-matched contemporary control group of people who experienced OHCA in 12 counties where only emergency medical services was dispatched, providing advanced life support. Primary outcome was survival to 30 days. The analytic sample consisted of 2786 pairs (n=5572) derived from the total cohort of 7308 complete cases. The median time from emergency call to arrival of emergency medical services or first responder was 9 minutes in the intervention group versus 10 minutes in the controls ( P <0.001). The proportion of patients admitted alive to the hospital after resuscitation was 31.4% (875/2786) in the intervention group versus 24.9% (694/2786) in the controls (conditional odds ratio, 1.40; 95% confidence interval, 1.24-1.57). Thirty-day survival was 9.5% (266/2786) in the intervention group versus 7.7% (214/2786) in the controls (conditional odds ratio, 1.27; 95% confidence interval, 1.05-1.54)., Conclusions: In this nationwide interventional trial, using propensity score matching, dispatch of first responders in addition to emergency medical services in OHCA was associated with a moderate, but significant, increase in 30-day survival., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02184468., (© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Background: The HeartRescue Project is a multistate public health initiative focused on establishing statewide out-of-hospital cardiac arrest (OHCA) systems of care to improve case capture and OHCA care in the community, by emergency medical services (EMS), and at hospital level., Methods and Results: From 2011 to 2015 in the 5 original HeartRescue states, all adults with EMS-treated OHCA due to a presumed cardiac cause were included. In an adult population of 32.8 million, a total of 64 988 OHCAs-including 10 046 patients with a bystander-witnessed OHCA with a shockable rhythm-were treated by 330 EMS agencies. From 2011 to 2015, the case-capture rate for all-rhythm OHCA increased from an estimated 39.0% (n=6762) to 89.2% (n=16 103; P <0.001 for trend). Overall survival to hospital discharge was 11.4% for all rhythms and 34.0% in the subgroup with bystander-witnessed OHCA with a shockable rhythm. We observed modest temporal increases in bystander cardiopulmonary resuscitation (41.8-43.5%, P <0.001 for trend) and bystander automated external defibrillator application (3.2-5.6%, P <0.001 for trend) in the all-rhythm group, although there were no temporal changes in survival. There were marked all-rhythm survival differences across the 5 states (8.0-16.1%, P <0.001) and across participating EMS agencies (2.7-26.5%, P <0.001)., Conclusions: In the initial 5 years, the HeartRescue Project developed a population-based OHCA registry and improved statewide case-capture rates and some processes of care, although there were no early temporal changes in survival. The observed survival variation across states and EMS systems presents a future challenge to elucidate the characteristics of high-performing systems with the goal of improving OHCA care and survival., (© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Background: Emergency 9-1-1 callers use a wide range of terms to describe abnormal breathing in persons with out-of-hospital cardiac arrest (OHCA). These breathing descriptors can obstruct the telephone cardiopulmonary resuscitation (CPR) process., Methods and Results: We conducted an observational study of emergency call audio recordings linked to confirmed OHCAs in a statewide Utstein-style database. Breathing descriptors fell into 1 of 8 groups (eg, gasping, snoring). We divided the study population into groups with and without descriptors for abnormal breathing to investigate the impact of these descriptors on patient outcomes and telephone CPR process. Callers used descriptors in 459 of 2411 cases (19.0%) between October 1, 2010, and December 31, 2014. Survival outcome was better when the caller used a breathing descriptor (19.6% versus 8.8%, P <0.0001), with an odds ratio of 1.63 (95% confidence interval, 1.17-2.25). After exclusions, 379 of 459 cases were eligible for process analysis. When callers described abnormal breathing, the rates of telecommunicator OHCA recognition, CPR instruction, and telephone CPR were lower than when callers did not use a breathing descriptor (79.7% versus 93.0%, P <0.0001; 65.4% versus 72.5%, P =0.0078; and 60.2% versus 66.9%, P =0.0123, respectively). The time interval between call receipt and OHCA recognition was longer when the caller used a breathing descriptor (118.5 versus 73.5 seconds, P <0.0001)., Conclusions: Descriptors of abnormal breathing are associated with improved outcomes but also with delays in the identification of OHCA. Familiarizing telecommunicators with these descriptors may improve the telephone CPR process including OHCA recognition for patients with increased probability of survival., (© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Background: The International Liaison Committee on Resuscitation (ILCOR) periodically updates the consensus recommendations for cardiopulmonary resuscitation to improve the outcomes of out-of-hospital cardiac arrest (OHCA). However, little is known about the differences in outcomes of witnessed OHCA following the publication of the ILCOR 2010 and the ILCOR 2005 recommendations., Methods and Results: We enrolled 241 990 adults who experienced witnessed OHCA between 2007 and 2013 from a prospective, nation-wide, population-based cohort database in Japan. We compared neurologically favorable 1-month survival and 1-month survival rates post-OHCA by dividing the study period into 2 categories: the ILCOR 2005 period and ILCOR 2010 period. The associations between guideline periods and outcomes were estimated using multivariable logistic regression analysis and reported as adjusted odds ratio and 95% CI. Among 241 990 patients examined in this study, OHCA was witnessed in 44 706 patients (18%) by emergency medical service personnel and in 197 284 patients (82%) by citizens. Compared with the ILCOR 2005 period, the neurologically favorable 1-month survival rate improved from 4.6% to 5.2% (adjusted odds ratio, 1.54; 95% CI, 1.42-1.67; P <0.001), and the 1-month survival rate improved from 9.0% to 9.7% (adjusted odds ratio, 1.34; 95% CI, 1.27-1.42; P <0.001) in the ILCOR 2010 period. These improvements were also shown in patients receiving conventional versus compression-only cardiopulmonary resuscitation., Conclusions: Outcomes of witnessed OHCA were better in the ILCOR 2010 period than those in the ILCOR 2005 period. Our results can provide baseline data for many future prospective studies., (© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Background: Bystander cardiopulmonary resuscitation (CPR) more than doubles the chance of surviving an out-of-hospital cardiac arrest. Recent data have shown considerable regional variation in bystander CPR rates across the Australian state of Victoria. This study aims to determine whether there is associated regional variation in rates of CPR training and willingness to perform CPR in these communities., Methods and Results: We categorized each Victorian postcode as either a low or high bystander CPR region using data on adult, bystander-witnessed, out-of-hospital cardiac arrests of presumed cardiac etiology (n=7175) from the Victorian Ambulance Cardiac Arrest Registry. We then surveyed adult Victorians (n=404) and compared CPR training data of the respondents from low and high bystander CPR regions. Of the 404 adults surveyed, 223 (55%) resided in regions with low bystander CPR. Compared with respondents from high bystander CPR regions, respondents residing in regions with low bystander CPR had lower rates of CPR training (62% versus 75%, P =0.009) and lower self-ratings for their overall knowledge of CPR (76% versus 84%, P =0.04). There were no differences between the regions in their reasons for not having undergone CPR training or in their willingness to perform CPR. Rates of survival for bystander-witnessed, out-of-hospital cardiac arrests were significantly lower in low bystander CPR regions (15.7% versus 17.0%, P <0.001)., Conclusions: This study found lower rates of CPR training and lower survival in regions with lower rates of bystander CPR in Victoria, Australia. Targeting these regions with CPR training programs may improve bystander CPR rates and out-of-hospital cardiac arrest outcomes., (© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Background: Bystander cardiopulmonary resuscitation (CPR) is associated with increased survival from cardiac arrest, yet bystander CPR rates are low in many communities. The overall prevalence of CPR training in the United States and associated individual-level disparities are unknown. We sought to measure the national prevalence of CPR training and hypothesized that older age and lower socioeconomic status would be independently associated with a lower likelihood of CPR training., Methods and Results: We administered a cross-sectional telephone survey to a nationally representative adult sample. We assessed the demographics of individuals trained in CPR within 2 years (currently trained) and those who had been trained in CPR at some point in time (ever trained). The association of CPR training and demographic variables were tested using survey weighted logistic regression. Between September 2015 and November 2015, 9022 individuals completed the survey; 18% reported being currently trained in CPR, and 65% reported training at some point previously. For each year of increased age, the likelihood of being currently CPR trained or ever trained decreased (currently trained: odds ratio, 0.98; 95% CI, 0.97-0.99; P <0.01; ever trained: OR, 0.99; 95% CI, 0.98-0.99; P =0.04). Furthermore, there was a greater then 4-fold difference in odds of being currently CPR trained from the 30-39 to 70-79 year old age groups (95% CI, 0.10-0.23). Factors associated with a lower likelihood of CPR training were lesser educational attainment and lower household income ( P <0.01 for each of these variables)., Conclusions: A minority of respondents reported current training in CPR. Older age, lesser education, and lower income were associated with reduced likelihood of CPR training. These findings illustrate important gaps in US CPR education and suggest the need to develop tailored CPR training efforts to address this variability., (© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Background: The determination of appropriate duration of in-the-field cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrest (OHCA) patients is one of the biggest challenges for emergency medical service providers and clinicians. The appropriate CPR duration before termination of resuscitation remains unclear and may differ based on initial rhythm. We aimed to determine the relationship between CPR duration and post-OHCA outcomes., Methods and Results: We analyzed the records of 17 238 OHCA patients (age ≥18 years) who achieved prehospital return of spontaneous circulation. Data were prospectively recorded in a nationwide, Japanese database between 2011 and 2012. The time from CPR initiation to prehospital return of spontaneous circulation (CPR duration) was calculated. The primary end point was 1-month survival with favorable neurological outcomes (Cerebral Performance Category [CPC] scale; CPC 1-2). The 1-month CPC 1-2 rate was 21.8% (n=3771). CPR duration was inversely associated with 1-month CPC 1-2 (adjusted unit odds ratio: 0.95, 95% CI: 0.94-0.95). Among all patients, a cumulative proportion of >99% of 1-month CPC 1-2 was achieved with a CPR duration of 35 minutes. When sorted by the initial rhythm, the CPR duration producing more than 99% of survivors with CPC 1-2 was 35 minutes for shockable rhythms and pulseless electrical activity, and 42 minutes for asystole., Conclusions: CPR duration was independently and inversely associated with favorable 1-month neurological outcomes. The critical prehospital CPR duration for OHCA was 35 minutes in patients with initial shockable rhythms and pulseless electrical activity, and 42 minutes in those with initial asystole., (© 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.)

Background: Most studies on out-of-hospital cardiac arrest have focused on immediate survival. However, little is known about long-term outcomes and resource use among survivors., Methods and Results: Within the national CARES registry, we identified 16 206 adults 65 years or older with an out-of-hospital cardiac arrest between 2005 and 2010. Among 1127 patients who were discharged alive, we evaluated whether 1-year mortality, cumulative readmission incidence, and follow-up inpatient costs differed according to patients' race, sex, initial cardiac arrest rhythm, bystander delivery of cardiopulmonary resuscitation, discharge neurological status, and functional status (hospital discharge disposition). Overall 1-year mortality after hospital discharge was 31.8%. Among survivors, there were no long-term mortality differences by sex, race, or initial cardiac arrest rhythm, but worse functional status and severe neurological disability at discharge were associated with higher mortality. Moreover, compared with first responders, cardiopulmonary resuscitation delivered by bystanders was associated with 23% lower mortality (hazard ratio 0.77 [confidence interval 0.58-1.02]). Besides mortality, 638 (56.6%) patients were readmitted within the first year, and the cumulative readmission incidence was 197 per 100 patient-years. Mean 1-year inpatient costs were $23 765±41 002. Younger age, black race, severe neurological disability at discharge, and hospital disposition to a skilled nursing or rehabilitation facility were each associated with higher 1-year inpatient costs (P for all <0.05)., Conclusion: Among elderly survivors of out-of-hospital cardiac arrest, nearly 1 in 3 patients die within the first year. Long-term mortality and inpatient costs differed substantially by certain demographic factors, whether cardiopulmonary resuscitation was initiated by a bystander, discharge neurological status, and hospital disposition., (© 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.)

Introduction: Survival from out-of-hospital cardiac arrest (OHCA) varies by community and emergency medical services (EMS) system. We hypothesized that the adoption of multiple best practices to focus EMS crews on high-quality, minimally interrupted cardiopulmonary resuscitation (CPR) would improve survival of OHCA patients in Salt Lake City., Methods and Results: In September 2011, Salt Lake City Fire Department EMS providers underwent a systemwide restructuring of care for OHCA patients that focused on the adoption of high-quality CPR with minimal interruptions and offline medical review of defibrillator data and feedback on CPR metrics. Victims were directed to ST-elevation myocardial infarction receiving centers. Prospectively collected data on patient survival and neurological outcome for all OHCAs were compared. In the postintervention period, there were 407 cardiac arrests with 65 neurologically intact survivors (16%), compared with 330 cardiac arrests with 25 neurologically intact survivors (8%) in the preintervention period. Among patients who survived to hospital admission, a higher proportion in the postintervention period survived to hospital discharge (71/141 [50%] versus 36/98 [37%], P=0.037) and had a favorable neurological outcome (65 [46%] versus 25 [26%], P=0.0005) compared with patients treated before the protocol changes. The univariate odds ratio or the association between neurologically intact survival (cerebral performance category 1 and 2) and protocol implementation was 2.3 (95% CI 1.4 to 3.7, P=0.001). Among discharged patients, the distribution of cerebral performance category scores was more favorable in the postintervention period (P<0.0001)., Conclusions: A multifaceted protocol, including several American Heart Assocation best practices for the resuscitation of patients with OHCA, was associated with improved survival and neurological outcome., (© 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.)