Prehospital Return Of Spontaneous Circulation Research Articles

Coronary angiography and percutaneous coronary intervention in cardiac arrest patients without return of spontaneous circulation

ObjectivesThis study aimed to examine coronary angiography (CAG) findings, percutaneous coronary intervention (PCI) results and outcomes in out-of-hospital cardiac arrest patients (OHCA) without return of spontaneous circulation (ROSC) on admission to hospital. MethodsWe analyzed the OHCA register and compared CAG, PCI, and outcome data in patients with and without ROSC on admission to hospital. ResultsBetween January 2012 and December 2020, 697 OHCA patients were analyzed. Of these, 163 (23%) did not have ROSC at admission. Patients without ROSC were younger (59 vs. 61 years, p = 0.001) and had a longer resuscitation time (62 vs. 18 minutes, p < 0.001) than patients with ROSC. Significant coronary artery disease was highly prevalent in both groups (65% vs. 68%, p = 0.48). Patients without ROSC had higher rates of acute coronary occlusions (42% vs. 33%, p = 0.046), specifically affecting the left main stem (16% vs. 1%, p < 0.001). PCI was performed in 81 patients (50%) without ROSC and in 295 (55%) with ROSC (p = 0.21). The success rate was 86% in patients without ROSC and 90% in patients with ROSC (p = 0.33). Thirty-day survival was 24% in patients without ROSC and 70% in patients with ROSC. ConclusionsOHCA patients without ROSC on admission to hospital had higher acute coronary occlusion rates than patients with prehospital ROSC. PCI is feasible with a high success rate in patients without ROSC. Despite prolonged resuscitation times, meaningful survival in patients admitted without ROSC is achievable.

Clinical evaluation of the use of laryngeal tube versus laryngeal mask airway for out-of-hospital cardiac arrest by paramedics in Singapore.

It remains unclear which advanced airway device has better placement success and fewer adverse events in out-of-hospital cardiac arrests (OHCAs). This study aimed to evaluate the efficacy of the VBM laryngeal tube (LT) against the laryngeal mask airway (LMA) in OHCAs managed by emergency ambulances in Singapore. This was a real-world, prospective, cluster-randomised crossover study. All OHCA patients above 13 years of age who were suitable for resuscitation were randomised to receive either LT or LMA. The primary outcome was placement success. Per-protocol analysis was performed, and the association between outcomes and airway device group was compared using multivariate binomial logistic regression analysis. Of 965 patients with OHCAs from March 2016 to January 2018, 905 met the inclusion criteria, of whom 502 (55.5%) were randomised to receive LT while 403 (44.5%) were randomised to receive LMA. Only 174 patients in the LT group actually received the device owing to noncompliance. Placement success rate for LT was lower than for LMA (adjusted odds ratio [OR] 0.52, 95% confidence interval [CI] 0.31-0.90). Complications were more likely when using LT (OR 2.82,0 95% CI 1.64-4.86). Adjusted OR for prehospital return of spontaneous circulation (ROSC) was similar in both groups. A modified intention-to-treat analysis showed similar outcomes to the per-protocol analysis between the groups. LT was associated with poorer placement success and higher complication rates than LMA. The likelihood of prehospital ROSC was similar between the two groups. Familiarity bias and a low compliance rate to LT were the main limitations of this study.

Procainamide for shockable rhythm cardiac arrest in the Resuscitation Outcome Consortium

BackgroundWith recent negative studies of amiodarone and lidocaine for cardiac arrest, research into other antiarrhythmics is warranted. Literature on procainamide in cardiac arrest is limited. We evaluated procainamide for out-of-hospital cardiac arrests (OHCA) from the Resuscitation Outcomes Consortium (ROC). MethodsWe included all ROC Epistry 3 OHCAs with an initial shockable rhythm that received an antiarrhythmic. We stratified cases by antiarrhythmic: procainamide, amiodarone, or lidocaine. The outcomes were prehospital return of spontaneous circulation (ROSC), ROSC in the ED, and survival to hospital discharge. We defined propensity scores based on possible confounders utilizing 1:1 propensity score matching to compare procainamide to amiodarone and lidocaine. We analyzed the matched data using logistic regression. We also used multivariable logistic regression to evaluate the association between antiarrhythmic and outcomes. Results3087 subjects met inclusion criteria; 51 patients received only procainamide, 1776 received amiodarone, and 1418 received lidocaine. On propensity score analysis and compared to procainamide, amiodarone had similar prehospital ROSC (OR 0.7, 95% CI 0.3–1.8), ED ROSC (OR 0.6, 95% CI 0.3–1.3), and survival (OR 1.0, 95% CI 0.3–3.1). Lidocaine also had a similar prehospital ROSC (OR 0.9, 95% CI 0.4–2.2), ED ROSC (OR 1.2, 95% CI 0.5–2.7), and survival (OR 1.4, 95% CI 0.5–4.0). However, using multivariable regression, amiodarone had lower prehospital ROSC than procainamide (aOR 0.3, 95% CI 0.1–0.6). ConclusionsWhile associated with increased prehospital ROSC when compared with amiodarone using multivariable regression, procainamide otherwise had similar prehospital ROSC, ED ROSC, and survival. The role of procainamide in OHCA remains unclear.

Effect of Placement of a Supraglottic Airway Device vs Endotracheal Intubation on Return of Spontaneous Circulation in Adults With Out-of-Hospital Cardiac Arrest in Taipei, Taiwan

Prehospital advanced airway management with either initial endotracheal intubation (ETI) or initial supraglottic airway (SGA) insertion in patients with out-of-hospital cardiac arrest (OHCA) remains controversial. To compare the effectiveness of ETI and SGA in patients with nontraumatic OHCA. The Supraglottic Airway Device vs Endotracheal intubation (SAVE) trial was a multicenter cluster randomized clinical trial conducted in Taipei City, Taiwan. Individuals aged 20 years or older who experienced nontraumatic OHCA requiring advanced airway management and were treated by participating emergency medical service agencies were enrolled from November 11, 2016, to December 31, 2019. The final day of follow-up was February 19, 2020. Four advanced life support ambulance teams were divided into 2 randomization clusters, with each cluster assigned to either ETI or SGA in a biweekly period. The primary outcome of the SAVE trial was sustained return of spontaneous circulation (ROSC) (≥2 hours) after resuscitation. Secondary outcomes included prehospital ROSC, survival to hospital discharge, and favorable neurologic outcome, defined as a cerebral performance category score less than or equal to 2. Prespecified subgroups and the association between time to advanced airways were explored. Per protocol and intention-to-treat analysis were performed. A total of 936 patients (517 in the ETI group and 419 in the SGA group) were included in the primary analysis (median age, 77 [IQR, 62-85] years; 569 men [60.8%]). The first-attempt airway success rates were 77% with ETI (n = 413) and 83% with SGA (n = 360). Sustained ROSC was 26.9% (n = 139) in the ETI group vs 25.8% (n = 108) in the SGA group. The odds ratio of sustained ROSC was 1.02 (95% CI, 0.98-1.06) in the ETI group vs SGA group. The odds ratio of ETA vs SGA was 1.04 (95% CI, 1.02-1.07) for prehospital ROSC, 1.00 (95% CI, 0.94-1.06) for survival to hospital discharge, and 0.99 (95% CI, 0.94-1.03) for cerebral performance category scores less than or equal to 2. In this randomized clinical trial, among patients with OHCA, initial airway management with ETI did not result in a favorable outcome of sustained ROSC compared with SGA device insertion. ClinicalTrials.gov Identifier: NCT02967952.

Prognostic value of targeted temperature management on outcomes of hanging-induced out-of-hospital cardiac arrest: A nationwide observational study.

This study aimed to evaluate the prognostic significance of targeted temperature management (TTM) on hanging-induced out-of-hospital cardiac arrest (OHCA) patients using nationwide data of South Korea.Adult hanging-induced OHCA patients from 2008 to 2018 were included in this nationwide observational study. Patients who assigned into 2 groups based on whether they did (TTM group) or did not (non-TTM group) receive TTM. Outcome measures included survival to hospital discharge and a good neurological outcome at hospital discharge.Among the 293,852 OHCA patients, 3545 patients (non-TTM, n = 2762; TTM, n = 783) were investigated. After propensity score matching for all patients, 783 matched pairs were available for analysis. We observed no significant inter-group differences in the survival to hospital discharge (non-TTM, n = 27 [3.4%] vs TTM, n = 23 [2.9%], P = .666) or good neurological outcomes (non-TTM, n = 23 [2.9%] vs TTM, n = 14 [1.8%], P = .183). In the multivariate analysis, prehospital return of spontaneous circulation (odds ratio [OR], 22.849; 95% confidence interval [CI], 11.479–45.481, P < .001) was associated with an increase in survival to hospital discharge, and age (OR, 0.971; 95% CI, 0.944–0.998, P = .035), heart disease (OR, 16.875; 95% CI, 3.028–94.036, P = .001), and prehospital return of spontaneous circulation (OR, 133.251; 95% CI, 30.512–581.930, P < .001) were significant prognostic factors of good neurological outcome. However, TTM showed no significant association with either outcome.There were no significant differences in the survival to hospital discharge and good neurological outcomes between non-TTM and TTM groups of hanging-induced OHCA patients.

Development and Validation of an Interpretable Prehospital Return of Spontaneous Circulation (P-ROSC) Score for Out-of-Hospital Cardiac Arrest Patients Using Machine Learning

Development and Validation of an Interpretable Prehospital Return of Spontaneous Circulation (P-ROSC) Score for Out-of-Hospital Cardiac Arrest Patients Using Machine Learning

Time point for transport initiation in out-of-hospital cardiac arrest cases with ongoing cardiopulmonary resuscitation: anationwide cohort study in Japan.

AimThis study aimed to investigate the time point of the decision to initiate transport with ongoing cardiopulmonary resuscitation (CPR) in Japan.MethodsWe analyzed adult out‐of‐hospital cardiac arrest (OHCA) cases that achieved return of spontaneous circulation (ROSC) before hospital arrival from the All‐Japan Utstein Registry during 2015–2017. We constructed receiver operating characteristics (ROC) curves to illustrate the ability of achieving ROSC as a predictor of neurologically favorable outcomes as a function of increasing time points of resuscitation before ROSC. Furthermore, a multivariable logistic regression analysis was carried out to identify factors associated with outcomes.ResultsOf 373,993 OHCA patients with attempted resuscitation during 2015–2017, 22,067 patients with prehospital ROSC were included in our study. Patients were divided into the shockable initial rhythm (n = 5,580) and nonshockable initial rhythm (n = 16,487) cohorts. The ROC curves showed 10 min was the best test performance time point for a neurologically favorable outcome for shockable initial rhythm patients (sensitivity, 0.78; specificity, 0.53; area under the ROC curve [AUC], 0.70) and 8 min for nonshockable initial rhythm patients (sensitivity, 0.74; specificity, 0.77; AUC, 0.83). Multivariable logistic regression analyses revealed that CPR durations using the cut‐off value were independently associated with better outcomes for both shockable initial rhythm patients (odds ratio, 2.09; 95% confidence interval, 1.81–2.42) and nonshockable initial rhythm patients (odds ratio, 3.34; 95% confidence interval, 2.92–3.82).ConclusionWhen Japanese emergency medical service (EMS) providers attend OHCA cases, the decision to initiate transport with ongoing CPR should be made at approximately 10 min after EMS providers initiate CPR for shockable initial rhythm patients and at approximately 8 min for nonshockable initial rhythm patients.

Effect of implementation of multi-tier response system and prolonged on-scene resuscitation for out-of-hospital cardiac arrest.

The purpose of this study was to explain the process and results of implementing a bundle of two cardiopulmonary resuscitation (CPR) programs in Gwang-ju metropolitan city and to determine whether the use of these programs improved the clinical outcomes for out-of-hospital cardiac arrest (OHCA) patients. This was a before- and after-intervention study of the implementation of a bundle of two CPR programs in Gwang-ju. The main intervention was a multi-tier response (MTR) system, with an emphasis on prolonged on-scene resuscitation. The primary outcome was good neurological recovery, and secondary outcomes were survival to discharge and prehospital return of spontaneous circulation (ROSC). A multivariable logistic regression model was used to estimate the association between the study period and outcomes, after adjusting for potential confounders. Interaction analysis was conducted to determine whether the location of arrest and witness status modified the effect of the study period on the study outcomes. The adjusted odds ratios (AORs) for the intervention were 1.35 (0.96-1.90) for pre-hospital ROSC, 1.19 (0.49-2.86) for survival to discharge, and 3.45 (1.01-11.80) for good CPC. The AORs for good neurological recovery of the after-intervention period were 2.93 (0.73-11.77) for a private place, 4.82 (1.04-22.39) for a public place, 5.88 (1.47-23.57) for a witnessed arrest, and 1.49 (0.28-7.86) for a non-witnessed arrest. OHCA patients treated in the after-intervention period with the bundle of CPR programs including MTR and prolonged on-scene resuscitation showed better clinical outcomes, especially pre-hospital ROSC, and neurological recovery at hospital discharge than those treated in the before-intervention period.

Impact of Cardiac Arrest Centers on the Survival of Patients With Nontraumatic Out-of-Hospital Cardiac Arrest: A Systematic Review and Meta-Analysis.

BackgroundThe 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 ResultsElectronic 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.ConclusionsCare 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.

Prehospital Factors Associated with Refractory Traumatic Arrest.

Objective Identification of the prehospital factors associated with a poor prognosis of immediate traumatic arrest should help reduce unwarranted treatment. We aim to reveal the clinical factors related to death after traumatic arrest on the scene. Methods We performed a multicenter (4 tertiary hospitals in urban areas of South Korea) retrospective study on consecutive adult patients with trauma arrest on scene who were transferred by fire ambulance from January 2016 to December 2018. Patients with death on arrival in the emergency room (ER) were excluded. Prehospital data were collected from first aid records, and information on each patient's survival outcome in the ER was collected from an electronic database. Patients were divided into ER death and ER survival groups, and variables associated with prehospital trauma were compared. Results A total of 145 (84.3%) and 27 (15.7%) patients were enrolled in the ER death and survival groups, respectively. Logistic regression analysis revealed that asystole (OR 4.033, 95% CI 1.342–12.115, p = 0.013) was related to ER death and that ROSC in the prehospital phase (OR 0.100, 95% CI 0.012–0.839, p = 0.034) was inversely related to ER death. In subgroup analysis of those who suffered fall injuries, greater height of fall was associated with ER death (15.0 (5.5–25.0) vs. 4.0 (2.0–7.5) meters, p = 0.001); the optimal height cutoff for prediction of ER death was 10 meters, with 66.1% sensitivity and 100% specificity. Conclusions In cases of traumatic arrest, asystole, no prehospital ROSC, and falls from a greater height were associated with trauma death in the ER. Termination of resuscitation in traumatic arrest cases should be done on the basis of comprehensive clinical factors.

The Influence of COVID-19 on Out-Hospital Cardiac Arrest Survival Outcomes: An Updated Systematic Review and Meta-Analysis.

Cardiopulmonary resuscitation in patients with out-of-hospital cardiac arrest (OHCA) is associated with poor prognosis. Because the COVID-19 pandemic may have impacted mortality and morbidity, both on an individual level and the health care system as a whole, our purpose was to determine rates of OHCA survival since the onset of the SARS-CoV2 pandemic. We conducted a systematic review and meta-analysis to evaluate the influence of COVID-19 on OHCA survival outcomes according to the PRISMA guidelines. We searched the literature using PubMed, Scopus, Web of Science and Cochrane Central Register for Controlled Trials databases from inception to September 2021 and identified 1775 potentially relevant studies, of which thirty-one articles totaling 88,188 patients were included in this meta-analysis. Prehospital return of spontaneous circulation (ROSC) in pre-COVID-19 and COVID-19 periods was 12.3% vs. 8.9%, respectively (OR = 1.40; 95%CI: 1.06–1.87; p < 0.001). Survival to hospital discharge in pre- vs. intra-COVID-19 periods was 11.5% vs. 8.2% (OR = 1.57; 95%CI: 1.37–1.79; p < 0.001). A similar dependency was observed in the case of survival to hospital discharge with the Cerebral Performance Category (CPC) 1–2 (6.7% vs. 4.0%; OR = 1.71; 95%CI: 1.35–2.15; p < 0.001), as well as in the 30-day survival rate (9.2% vs. 6.4%; OR = 1.63; 95%CI: 1.13–2.36; p = 0.009). In conclusion, prognosis of OHCA is usually poor and even worse during COVID-19.

Development and validation of the SARICA score to predict survival after return of spontaneous circulation in out of hospital cardiac arrest using an interpretable machine learning framework

BackgroundAccurate and timely prognostication of patients with out-of-hospital cardiac arrest (OHCA) who achieved the return of spontaneous circulation (ROSC) is crucial in clinical decision-making, resource allocation, and communications with next-of-kins. We aimed to develop the Survival After ROSC in Cardiac Arrest (SARICA), a practical clinical decision tool to predict survival in OHCA patients who attained ROSC. MethodsWe utilized real-world Singapore data from the population-based Pan-Asian Resuscitation Outcomes Study between 2010–2018. We excluded patients without ROSC. The dataset was segmented into training (60%), validation (20%) and testing (20%) cohorts. The primary endpoint was survival (to 30-days or hospital discharge). AutoScore, an interpretable machine-learning based clinical score generation algorithm, was used to develop SARICA. Candidate factors were chosen based on objective demographic and clinical factors commonly available at the time of admission. Performance of SARICA was evaluated based on receiver-operating curve (ROC) analyses. Results5970 patients were included, of which 855 (14.3%) survived. A three-variable model was determined to be most parsimonious. Prehospital ROSC, age, and initial heart rhythm were identified for inclusion via random forest selection. Finally, SARICA consisted of these 3 variables and ranged from 0 to 10 points, achieving an area under the ROC (AUC) of 0.87 (95% confidence interval: 0.84–0.90) within the testing cohort. ConclusionWe developed and internally validated the SARICA score to accurately predict survival of OHCA patients with ROSC at the time of admission. SARICA is clinically practical and developed using an interpretable machine-learning framework. SARICA has unknown generalizability pending external validation studies.

Effects of pre-hospital re-arrest on outcomes based on transfer to a heart attack centre in patients with out-of-hospital cardiac arrest

AimWe aimed to investigate the interaction effects between transfer to a heart attack centre [HAC] and prehospital re-arrest on the clinical outcomes of patients with out-of-hospital cardiac arrest [OHCA]. MethodsWe included adult patients with OHCA of presumed cardiac aetiology from January 2012 to December 2018. The main exposure variable was prehospital re-arrest, defined as recurrence of cardiac arrest with a loss of palpable pulse upon hospital arrival. The other exposure variable was the resuscitation capacity of the receiving hospital [HAC or Non-HAC]. The outcome variable was neurological recovery. A multivariable logistic regression was performed to determine the interaction effects. ResultsThe final analysis included 6935 patients. Of these, 21.9% (n = 1521) experienced prehospital re-arrest, whereas 41.3% (n = 2866) were transferred to a non-HAC. The prehospital re-arrest group associated with poor neurological recovery (adjusted odds ratio [AOR], 0.25; 95% confidence interval [CI], 0.21–0.29;). Transfer to an HAC had beneficial effects on neurological recovery (AOR, 3.40 [95% CI, 3.04–3.85]. In the interaction model, wherein prehospital re-arrest patients who were transferred to a non-HAC were used as reference, the AOR of prehospital re-arrest patients who were transferred to an HAC, non-re-arrest patients who were transferred to a non-HAC, and non-re-arrest patients who were transferred to a non-HAC was 2.41 (95% CI, 1.73–3.35), 3.09 (95% CI, 2.33–4.10), and 11.07 (95% CI, 8.40–14.59) respectively (interaction p = 0.001). ConclusionTransport to a heart attack centre was beneficial to the clinical outcomes of patients who achieved prehospital ROSC after OHCA. The magnitude of that benefit was significantly modified by whether prehospital re-arrest had occurred.

Abstract 9114: Impact of the Number of Prehospital Defibrillation Attempts on Neurologically Intact Survival in Patients With Out-of-Hospital Cardiac Arrest and Shockable Rhythm

Background: Early return of spontaneous circulation (ROSC) leads to survival with a favorable neurologic outcome in patients with out-of-hospital cardiac arrest (OHCA). For the early ROSC, defibrillation plays a crucial role for OHCA with shockable rhythm. However, little is known about the relation between the number of prehospital defibrillation attempts or etiology of OHCA and neurologically intact survival. Methods: Using a nationwide OHCA registry database from 2005 to 2017 in Japan, a cohort of 1,527,447 patients with OHCA were retrospectively analyzed. We included the patients of witnessed OHCAs with initial shockable rhythm. The relation between early ROSC, defined as prehospital ROSC achieved with defibrillation ≤3 times without adrenaline, and a neurologically intact survival rate (cerebral performance category score of 1 or 2 at 1 month) was evaluated. We also analyzed factors related to the successful early ROSC, including etiology of OHCA. Results: A total of 75,342 patients were included. Among patients with OHCA and prehospital ROSC, neurologically intact survival rates were better in patients who achieved early ROSC than their counterpart (62% vs. 36%, p&lt;0.001). Success in early ROSC was an independent predictor of neurologically intact survival after adjustment of multiple cofounders (Table). Multivariate analysis showed cerebral vascular disease as an etiology of OHCA was a predictor of early ROSC (odds ratio 1.15, 95% confidence interval 1.03-1.29, p=0.02), but was significantly associated with a poor neurologic outcome at 1 month (Table). Conclusions: Success in early ROSC was associated with neurologically intact survival in patients with OHCA and initial shockable rhythm. Patients with OHCA due to cerebral vascular disease were likely to be resuscitated from cardiac arrest by defibrillations but had a poor neurologic outcome.

Abstract 12088: Coronary Angiography and Revascularization After Out-of-Hospital Cardiac Arrest in Coronary Artery Disease Patients Without ST-segment Elevation

Introduction: The emergent coronary angiography and revascularization after out-of-hospital cardiac arrest (OHCA) in coronary artery disease (CAD) patients without ST-segment elevation remains controversial. Methods: There were 2391OHCA patients transferred to 2 hospitals. We included 405 cardiovascular arrest patients, who got return of spontaneous circulation (ROSC) from January 2015 to December 2018. Among them, 110 patients were diagnosed CAD with no ST-segment elevation in electro-cardiogram (51%: multi-vessel disease, 33%: chronic total occlusion). To predict mortality in hospital and neurological outcome at 1-year, we investigated basic patients’ characteristics, pre-hospital information, post-hospital care including coronary angiography (CAG) and revascularization. Results: In the Cox proportional hazards model, emergent coronary angiography (hazards ratio; HR: 0.90, 95%confidence interval (CI) 0.45-1.79, P=0.758) and emergent coronary revascularization (HR: 1.51, 95%CI 0.87-2.61, P=0.142) were not associated to predict the mortality. At 1-year, VF survivor (P=0.004), younger age (P=0.010), without ECMO support (P&lt;0.001), pre-hospital ROSC (P&lt;0.001), and low lactate level on admission (P&lt;0.001) were associated with low mortality. The higher number of coronary vessel disease (P=0.020) such as multi-vessel disease (P=0.019), the coronary lesion of LAD (P=0.043), and larger infarct size (max CK level; P=0.014, max CK-MB level; P&lt;0.001) were associated with high 1-year mortality. Zero-vessel disease (VSA, P=0.007) had lower mortality. Conclusions: Emergent coronary assessment and revascularization were not associated with the prognosis.

Abstract 8875: Early Compared to Late Administration of Epinephrine in Adults With Shockable Initial Rhythm Out-of-Hospital Cardiac Arrest

Introduction: The optimal timing of epinephrine administration in shockable initial rhythm out-of-hospital cardiac arrest (OHCA) is unclear. Hypothesis: Early compared to late epinephrine following first electrical defibrillation attempt is associated with better outcomes in shockable initial rhythm OHCA. Methods: We conducted a retrospective study in adults with shockable initial rhythm OHCA from 2011-2015 in North America. We used multivariable logistic regression to assess associations between timing of epinephrine and prehospital return of spontaneous circulation (ROSC), survival to hospital discharge, and hospital discharge with favorable neurological outcome (modified Rankin Scale score≤3). We used propensity-score-matching and subgroup analyses to assess robustness of associations. Results: Of 6416 patients, median age was 64 (IQR: 54-74) years, 5136 (80%) were men, 2226 (35%) received epinephrine within four minutes after first defibrillation, 5119 (80%), 1237 (19%), and 996 (16%) had prehospital ROSC, survival to hospital discharge, and favorable neurological outcome at discharge respectively. Adjusted for confounders, we observed lower odds of prehospital ROSC (OR=0.95, 95%CI 0.94-0.96; p&lt;0.001), survival to hospital discharge (OR=0.91, 95%CI 0.89-0.92; p&lt;0.001), and favorable neurological outcomes at discharge (OR=0.92, 95%CI 0.90-0.93; p&lt;0.001) per minute later epinephrine administration. Compared to epinephrine administration within four minutes following first defibrillation attempt, later epinephrine was associated with lower odds of prehospital ROSC (OR=0.58, 95%CI 0.51-0.68; p&lt;0.001), survival to hospital discharge (OR=0.50, 95%CI 0.43-0.58; p&lt;0.001), and favorable neurological outcome at discharge (OR=0.51, 95%CI 0.43-0.59; p&lt;0.001). Associations remained significant in a well-balanced propensity score matched cohort and subgroup analyses by witness status, EMS response time, and total epinephrine dose. Conclusion: In shockable initial rhythm OHCA, early compared to late epinephrine administration following first defibrillation attempt was associated with better odds of prehospital ROSC, survival to hospital discharge, and hospital discharge with favorable neurological outcome.

Abstract 12185: Impact of Cardiac Arrest Centers on the Survival of Nontraumatic Out-of-Hospital Cardiac Arrest Patients: A Systematic Review and Meta-Analysis

Introduction: The role of cardiac arrest centers (CAC) in out-of-hospital cardiac arrest (OHCA) is uncertain, especially since CACs are inconsistently defined. This study seeks to address knowledge gaps by assessing the impact of CACs on nontraumatic OHCA patients as a whole and among specific subgroups. Methods: In this review, Medline, Embase, and Cochrane CENTRAL were searched from inception to 9 March 2021. Studies were included if they compared CAC vs non-CAC among adult patients with nontraumatic OHCA. CACs were explicitly named by study authors and were capable of appropriate interventions. Data abstraction and quality assessment were independently conducted by two authors, and a third author resolved discrepancies. Main outcomes were survival and survival with favorable neurological outcome at hospital discharge or at 30 days. Meta-analyses were performed for adjusted (aOR) and crude (OR) odds ratios. Sensitivity analyses were conducted for wider definitions of CAC such as high volume centers or improved post-resuscitation care, and subgroups analysed to account for heterogeneity. Results: The search yielded 4544 articles, and 36 were included for analysis. Survival with favorable neurological outcome significantly improved with treatment at CACs (aOR = 1.88, 95% CI 1.53 to 2.31), even when including high volume centers (aOR = 1.68, 95% CI 1.30 to 2.16), or when including improved care centers (aOR = 2.16, 95% CI 1.76 to 2.64) as CACs. Survival significantly increased with treatment at CAC (aOR = 1.92, 95% CI 1.59 to 2.31), even when including high volume centers (aOR = 1.74, 95% CI 1.38 to 2.18), or when including improved care centers (aOR = 1.97, 95% CI 1.71 to 2.26) as CACs. The effect on favorable neurological outcome was more pronounced among patients with shockable rhythm (p = 0.03) and on survival among patients without prehospital ROSC (p = 0.005). Findings were robust to sensitivity analyses, with no publication bias detected. Conclusion: CACs improved survival and neurological outcomes for nontraumatic OHCA patients despite varying definitions of CAC. Patients with shockable rhythms and without prehospital ROSC appeared to yield greater benefit from CACs. Evidence for bypassing hospitals or inter-hospital transfer remains inconclusive.

Abstract 9502: Prehospital Variables Associated With Neurologically Intact Survival in Elderly Survivors After Out-of-Hospital Cardiac Arrest: Evidence from a Japanese Nationwide Population-based Cohort Study

Introduction: Prehospital variables associated with neurologically intact survival in elderly survivors after out-of-hospital cardiac arrest (OHCA) are unclear and could differ according to age. Methods: We evaluated 6,349 elderly patients with OHCA (age ≥ 65 years) of cardiac origin who achieved prehospital return of spontaneous circulation (ROSC) and survived for at least 1-month after OHCA. Data were obtained from the prospectively recorded All-Japan Utstein Registry between 2011 and 2016. Patients witnessed by emergency medical service providers were excluded. The primary outcome was 1-month neurologically intact survival, defined as a cerebral performance category (CPC) score of 1-2. Patients were divided into three groups by age (65-74, 75-89, or ≥ 90 years). The time from call receipt to ROSC was calculated. Results: The rates of 1-month CPC 1-2 in patients aged 65-74, 75-89, and ≥ 90 years were 66.5% (2,079/3,125), 52.9% (1,557/2,943), and 42.7% (120/281), respectively (p for trend &lt; 0.001). In multivariate logistic regression analysis, initial shockable rhythm and witnessed arrest were significantly associated with 1-month CPC 1-2 for all age groups (Table). However, the presence of bystander cardiopulmonary resuscitation (CPR) was significantly associated with 1-month CPC 1-2 only for patients aged 65-74 years. Time from call receipt to ROSC was not associated with 1-month CPC 1-2 for patients aged ≥ 90 years. In recursive partitioning analysis, the best single predictor for 1-month CPC 1-2 was initial shockable rhythm for all age groups. The next predictor for patients aged 65-74 years with initial shockable rhythm was the presence of bystander CPR, whereas the witnessed arrest was the next predictor for patients aged 65-74 years with initial non-shockable rhythm and other age groups regardless of the initial rhythm. Conclusions: Prehospital variables associated with neurologically intact survival in elderly survivors after OHCA varied with age.

Abstract 14171: Prehospital Outcomes and Patient Characteristics Associated With PulsePoint Dispatches for Out-of-Hospital Cardiac Arrest in Pittsburgh, Pennsylvania

Background: Mobile phone-based dispatch of volunteers to out-of-hospital cardiac arrest (OHCA) has been shown to increase the likelihood of early chest compressions and AED application. In the United States, limited characterization of patients encountered as a result of such systems exists, including PulsePoint Respond, a smartphone-based volunteer dispatch system. Objective: Examine prehospital case characteristics and outcomes from a multi-year deployment of PulsePoint in Pittsburgh, Pennsylvania. Methods: Case data, including PulsePoint determinant triggers and timing, prehospital electronic health records (EHRs), and computer aided dispatch records were obtained for suspected EMS-treated OHCA cases that did and did not generate PulsePoint alerts within the service area of Pittsburgh EMS for the period July 2016 to October 2020. EHRs were reviewed to determine true OHCA status, and OHCA case characteristics were extracted according to the Utstein template. Key characteristics and the outcome of prehospital return of spontaneous circulation (ROSC) were summarized and compared between cases with and without PulsePoint dispatches. Chi-squared tests were used to determine statistical significance of relationships. Results: There were 1229 OHCA cases overall in the capture period, with an estimated 29.6% occurring in public. Of 840 total PulsePoint dispatches, 68 (8.1%) were for true OHCA. Forty-five (66.2%) of these were witnessed, 43 (63.2%) received bystander CPR, and 17 (25%) had an AED applied prior to first responder arrival. Twenty-seven (39.7%) had an initial shockable rhythm, and 34 (50%) achieved ROSC in the field. Compared to non-PulsePoint dispatch generating OHCA, PulsePoint alert-associated patients were significantly more likely to be male (p=0.024), have bystander CPR/AED application performed (p&lt;0.001), have an initial shockable rhythm (p&lt;0.001), and achieve ROSC (p&lt;0.001). EMS response time, age, ALS response time, and witnessed status were not significantly different. Conclusions: A minority of PulsePoint dispatches in Pittsburgh were triggered by true OHCA. Among cases that did generate a PulsePoint dispatch, case characteristics were prognostically favorable.

Abstract 11112: Impact of Changes in Clinical Practice Guidelines on Survival Outcomes After Traumatic Out-of-Hospital Cardiac Arrest

Aim: In this study, we examine the impact of a trauma-based resuscitation protocol on survival outcomes following emergency medical services (EMS) witnessed traumatic out-of-hospital cardiac arrest (OHCA). Methods: We included EMS-witnessed OHCAs arising from trauma and occurring between 2008 and 2019. In December 2016, a new resuscitation protocol for traumatic OHCA was introduced prioritizing the treatment of potentially reversible causes before conventional cardiopulmonary resuscitation. The effect of the new protocol on survival outcomes was assessed using adjusted multivariable logistic regression models. Results: Paramedics attempted resuscitation on 490 patients, with 341 (69.6%) and 149 (30.4%) occurring during the control and intervention periods, respectively. A reduction in the proportion of cases receiving cardiopulmonary resuscitation and epinephrine administration were found in the intervention period compared to the control period, whereas trauma-based interventions increased significantly, including blood administration (pre-arrest: 17.9% vs 3.7%; intra-arrest: 24.1% vs 2.7%), splinting (pre-arrest: 38.6% vs 17.1%; intra-arrest: 20.7% vs 5.2%), and finger thoracostomy (pre-arrest: 13.1% vs 0.6%; intra-arrest: 22.8% vs 0.9%), respectively, with p-values &lt;0.001 for all comparisons. After adjustment, the trauma-based resuscitation protocol was not associated with an improvement in survival to hospital discharge (AOR 1.29, 95% CI: 0.51-3.23), event survival (AOR 0.72, 95% CI: 0.41-1.28) or prehospital return of spontaneous circulation (AOR 0.63, 95% CI: 0.39-1.03). Conclusion: In our region, the introduction of a trauma-based resuscitation protocol led to an increase in the delivery of almost all trauma interventions; however, this did not translate into better survival outcomes following EMS-witnessed traumatic OHCA.