bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 255: Independent Association of Interleukin 6 With Neuronal Injury Depend on Cardiac Arrest Severity in the Patients With Post Resuscitation Care
Authors: Lee Dong Young , Park Jung Soo , You Yeonho , Kang Changshin , Min Jinhong , In Yong Nam , Jeon So Young
Published: December 2023

Aim:
A recent trial did not demonstrate a significant relationship between interleukin 6 (IL-6) and neuronal injury, such as neuron-specific enolase (NSE). However, it is a well-understood concept throughout medicine that treatment effects depend on injury or disease severity. We hypothesize that IL-6 is independently associated with NSE according to cardiac arrest severity. Thus, this study aimed to investigate the relationship of IL-6 with NSE during post-resuscitation care according to cardiac arrest severity.

Methods:
This retrospective study included patients who underwent post-resuscitation care. IL-6 and NSE were measured at 0, 24, 48, and 72 h immediately after applying the temperature control device. We divided the cohort into three groups of low, moderate, and severe severity based on the “Revised Post-Cardiac Arrest Syndrome for Therapeutic Hypothermia” scoring system. Stepwise linear regression was performed to analyze the correlation of the entire IL-6 measured at all times with the inflammatory, myocardial injury, and neuronal injury markers to account for other covariables.

Results:
Of the 111 enrolled patients, 22, 59, and 28 were in low, moderate, and severe severity groups, respectively. Median IL-6 and NSE were significantly different between groups (IL-6, 145.2 pg/mL vs. 949.7 pg/mL vs. 1100.7 pg/mL, p = 0.001; NSE, 24.4 ng/mL vs. 48.7 ng/mL vs. 63.2 ng/mL, p = 0.001). Stepwise linear regression analysis revealed that the IL-6 did not significantly correlate with other markers in low severity groups (F = 2.38, p = 0.13); however, in the severe severity group, IL-6 was independently correlated with NSE in severe severity groups (β = 8.16, p = 0.001).

Conclusion:
IL-6 level was associated with cardiac arrest severity. IL-6 was independently correlated with NSE in the severe severity group but not in low to moderate severity groups. Therefore, the correlation between IL-6 and neuronal injury markers may be dependent on the cardiac arrest severity.
Abstract 260: Sociodemographic Analysis of Paediatric Out-of-Hospital Cardiac Arrest in Ontario, Canada: A Province-Wide Case-Control Study
Authors: Idrees Samina , Anderson Kelly K. , Choi Yun-Hee , Tijssen Janice A.
Published: December 2023

Background:
Paediatric out-of-hospital cardiac arrest (POHCA) is associated with significant mortality and severe neurological sequelae. Previous literature indicates that there are sociodemographic disparities in POHCA survival and in the provision of upstream interventions. However, it’s unclear if the populations impacted by these disparities also have an elevated risk of experiencing POHCA. We sought to describe the relationship between sociodemographic factors and POHCA risk in Ontario, Canada.

Methods:
We conducted a province-wide case-control study using health administrative data at ICES. The case group included children (1 day to 17 years of age) who experienced an OHCA between 2004 and 2020. Controls were matched up to 1:4 on age, sex, index date, and key comorbidities. We used conditional logistic regression to measure the association between POHCA and neighbourhood-level marginalization indicators, geographical context, and immigration status.

Results:
The case and control groups included 1,826 and 7,254 children, respectively. Children living in areas with the highest levels of material deprivation (adjusted odds ratio, aOR: 2.35, 95% CI: 1.94, 2.85) and dependency (aOR: 1.23, 95% CI: 1.02, 1.49) had a higher odds of POHCA, relative to children living in regions with the lowest levels of material deprivation and dependency, respectively. Children living in neighbourhoods with the lowest levels of ethnic diversity had a higher odds of POHCA (aOR: 1.34, 95% CI: 1.08, 1.67), as compared to children living in neighbourhoods with the highest levels of ethnic diversity. Northern urban (aOR: 1.42, 95% CI: 1.11, 1.82) and southern rural residence (aOR: 1.27, 95% CI: 1.04, 1.55) were associated with a higher odds of POHCA, relative to southern urban residence. The odds of POHCA were lower in child immigrants (aOR: 0.60, 95% CI: 0.42, 0.85) and maternal immigrants (aOR: 0.70, 95% CI: 0.61, 0.81), relative to the general population. The impact of residential instability was not significant in adjusted analyses.

Conclusion:
Children living in neighbourhoods with high levels of marginalization are likely at an elevated risk of experiencing POHCA. These communities should be prioritized in POHCA prevention and intervention efforts.
Abstract 273: Development and Implementation of a Multicenter Registry for Resuscitation-Focused Transesophageal Echocardiography
Authors: Teran Felipe , Owyang Clark G , Wray Trenton , Hipskind John , Lessard Justine , Bédard Michel William , Lanthier Chantal , Nazerian Peiman , de Villa Eleonora , Nogueira Jonathan , Doynow Daniel , Clinton Michelle , Myslik Frank , Prager Ross , Arntfield Robert , Salinas Pedro D , Dieiev Vladyslav , Woo Michael Y , Thavanathan Rajiv , Puskas Graeme , Singh Karan , Bhat Priyanka , Horn Jackson , Buchanan Brian M , Baig Nadia , Burns Katharine , Kennedy Kelsey , Haines Lawrence , Naraghi Leily , Singh Harpriya , Secko Michael , Singer Daniel , Taylor Maria , Joyce John M , DeMasi Stephanie , Jafry Zan M , Phan Tammy , Truong Natalie , Robinson Evan , Haycock Korbin H , Hansen Allyson , Derr Charlotte , Andrus Phillip , Razzak Junaid , Palasz Joanna , Kaviyarasu Aarthi , Sands Nathaniel A , Abella Benjamin S ,   The Resuscitative TEE Collaborative Registry Investigators
Published: December 2023

Objectives:
To evaluate the clinical impact, safety, and clinical outcomes of focused transesophageal echocardiography (TEE) in the evaluation of critically ill patients in the emergency department (ED) and intensive care units (ICU).

Methods:
We established a prospective, multicenter, observational registry involving adult critically ill patients in whom focused TEE was performed for evaluation of out-of-hospital cardiac arrest (OHCA), in-hospital cardiac arrest (IHCA), evaluation of undifferentiated shock, hemodynamic monitoring, and/or procedural guidance in the ED, ICU, or operating room (OR) setting. The primary objective of the current investigation was to evaluate the clinical impact and safety of focused, point-of-care TEE in critically ill patients. Data elements included patient and procedure characteristics, laboratory values, timing of interventions, clinical outcomes, and TEE video images.

Results:
A total of 771 cases were collected from 27 hospitals, including 506 (66%) intra and post arrest OHCA and IHCA, 221 (29%) initial evaluation of undifferentiated shock, 71 (9%) hemodynamic monitoring, and 93 (12%) procedural guidance. TEE changed management in 64% of cases of OHCA, in 71% of IHCA, and in 85% of patients with undifferentiated shock. There were no reported esophageal perforations or oropharyngeal injuries, and other procedural complications were rare.

Conclusion:
A prospective, multicenter, and multidisciplinary TEE registry was successfully implemented, and demonstrated that focused TEE is safe and clinically impactful across multiple critical care applications. Further studies from this research network will accelerate the development of outcome-oriented research and knowledge translation on the use of TEE in emergency and critical care settings.
Abstract 275: Point-of-Use Ultrasound in Out-of-Hospital Cardiac Arrest: A Meta-Analysis of Diagnostic Accuracy and Outcome Prediction
Authors: Elfaituri Muhammed K , Khaled Ala , BenGhatnsh Ahmed , Elfaituri Ahmed , Faraj Hazem Abdelkarem A , Msherghi Ahmed
Published: December 2023

Background:
Out-of-hospital cardiac arrest (OHCA) is a significant global health issue where accurate and rapid decision-making can often be the difference between life and death. Point-of-use ultrasound has been proposed as a potential tool to assist in such decisions by predicting patient outcomes. However, the current body of literature presents diverse results, thus emphasizing the need for an all-encompassing meta-analysis to assess the diagnostic accuracy of point-of-use ultrasound.

Aim:
This study aimed to determine the diagnostic accuracy of point-of-use ultrasound in predicting the outcomes of adult OHCA.

Methods:
We undertook a search of databases, including PubMed, Embase, and Cochrane Library, for studies published until November 2022 that investigated the role of point-of-use ultrasound in adult OHCA and its relation to patient outcomes. We utilized R software (version 4.0.3) equipped with the mada package for our statistical analysis, which allowed for pooling sensitivity, specificity, and false-positive rate estimates.

Results:
Nine studies were included in the final analysis. For survival to hospital discharge (four studies with a total of 1144 patients), the pooled sensitivity was 6.4% (95% Confidence Interval (CI): 1.2%-27.2%, I2=97.5%), specificity was 1.9% (95% CI: 0.9%-4.2%, I2=58.2%), the false-positive rate was 98.1% (95% CI: 95.8%-99.1%), the diagnostic odds ratio was 0.001 (95% CI: 0-0.009), positive LR was 0.065 (95% CI: 0.013-0.319), and negative LR was 49.15 (95% CI: 22.08-109.37). For the return of spontaneous circulation (ROSC) (six studies with a total of 1476 patients), the pooled sensitivity was 26.1% (95% CI: 17%-37.8%, I2=91.2%), specificity was 76.1% (95% CI: 42.1%-93.3%, I2=94.1%), the false-positive rate was 23.9% (95% CI: 6.7%-57.9%), diagnostic odds ratio was 1.13 (95% CI: 0.23-5.44), positive LR was 1.09 (95% CI: 0.33-3.61), and negative LR was 0.97 (95% CI: 0.66-1.42).

Conclusion:
Our study suggests that point-of-use ultrasound's predictive value for survival and ROSC in adult OHCA may be lower than anticipated, given high false-positive rates and low diagnostic odds ratios. These results underscore the need for further research before integrating ultrasound into OHCA decision-making.
Abstract 306: Evaluating Layperson CPR Performance Supported by a Just-in-Time Video Compared to a Standard Training Course
Authors: Goldberg Scott , Peters Greg , Cash Rebecca E , Jiang Dawei , O'Brien Conor , Hasdianda Mohammad Adrian , Eberl Eric , Salerno Kathleen , Lees Jacob , Kaithamattam Jenson , Tom Jeremiah , Goralnick Eric
Published: December 2023

Background:
Just-in-time (JIT) video training has been proposed as an alternative to in-person CPR courses, with associated time and cost savings.

Research Question:
Does a JIT training video improve layperson performance of CPR?

Aim:
Measure CPR performance using a JIT video compared to the American Heart Association (AHA) HeartSaver® CPR AED Training course.

Methods:
A convenience sample of laypeople was randomized to perform CPR in a simulated scenario a) after participating in an AHA HeartSaver® course led by experienced instructors, b) with access to a JIT training video, or c) control, with no assistance or training. CPR quality was assessed by trained evaluators and objective performance assessed using Laerdal QCPR-enabled simulators. The primary outcome was performance of correct CPR.

Results:
Of 230 eligible subjects, 226 were randomized with no significant differences in baseline characteristics across groups. Prevalence of correct CPR was low, though significantly higher in the AHA group (AHA: 40%, 95%CI 28-51; JIT: 15%, 95%CI 8-26; control 10%, 95%CI 4-19). Overall, 94% of participants performed compressions within 1 minute, with no difference between groups. An AED was called for more frequently in the AHA group (47%) than the JIT (15%) or control (10%) groups. Flow fraction was significantly better in the AHA group (89%, IQR 77-99) compared to the JIT (75%, IQR 47-90) or control (49%, IQR 22-74) groups and compression rates of 100-120 were more frequent in the AHA (51%) and JIT groups (47%) compared to controls (27%).

Conclusions:
While correct performance of specific CPR skills varied in this sample, laypersons using a JIT training video performed as well as those taking an AHA HeartSaver® course on several key measures such as rapid chest compression and compression rate. JIT video training may be a viable option for supporting untrained bystander CPR performance, though further evaluation is needed to identify optimal strategies for implementation.
Abstract 329: Unrecognized Clinical Deterioration Prior to In-Hospital Cardiac Arrest and Associated In-Hospital Mortality
Authors: Shipley Kipp , Shifrin Megan M , Roach Kathryn
Published: December 2023

Introduction:
Physiologic abnormalities often precede in-hospital cardiac arrest (IHCA). Critical Care Outreach Teams (CCOTs) are designed to respond to patients that meet standardized rapid response team (RRT) activation criteria including vital sign abnormalities, neurologic changes, and nursing concern. However, these systems often rely on clinical staff recognizing signs of clinical deterioration and initiating a rapid response.
Research Question:
The purpose of this post-hoc analysis was to identify if there was an in-hospital mortality difference between two different adult patient groups: 1) patients who met standardized RRT criteria but did not receive an RRT prior to IHCA and 2) patients who had no evidence of clinical deterioration prior to IHCA.
Goals:
The primary goal was to explore the association of unrecognized clinical deterioration on patient mortality. A secondary goal was to identify the timing onset of RRT criteria in patients who had an IHCA but did not receive an RRT activation.

Methods:
All non-ICU IHCAs during a 5-year period (January 1st, 2018, to December 31st, 2022) were reviewed to identify whether: 1) standardized RRT criteria had been met in the 24 hours prior to IHCA, 2) the onset of RRT criteria if present, 3) sustained return of spontaneous circulation (ROSC) occurred during the IHCA, and 4) if the patient died during their hospitalization.

Results:
There were 271 adult non-ICU IHCAs without a preceding RRT activation. Of those, 203 (79.4%) met RRT criteria prior to IHCA. In patients who had evidence of clinical deterioration, patients displayed at least one RRT criterion an average of 13.1 hours prior to IHCA. Sustained ROSC was higher in the patient group without RRT criteria (79.4%, 54/68 vs 72.9%, 148/203), but this was not significant. In-hospital mortality was significantly higher patients who met RRT criteria without RRT activation compared to patients who did not meet RRT criteria prior to IHCA (67.9%, 65/138 vs 54.4%, 31/37, p<0.05).

Conclusions:
Most patients who experienced an IHCA demonstrated physiologic abnormalities hours prior to IHCA. Patients who met RRT criteria without RRT activation had a significantly higher mortality rate when compared with patients who did not have evidence of clinical deterioration.
Abstract 335: The Potential of Using Passenger Flow to Guide AED Deployment at Train Stations
Authors: Pervez Sheikh Annam , Juul Grabmayr Anne , Kjoelbye Julie S , Kjær Ersbøll Annette , Malta Hansen Carolina , Folke Fredrik
Published: December 2023

Background:
According to earlier guidelines, many countries have deployed AEDs at train stations to improve survival after OHCA. However, train stations are heterogeneous in size and traffic, and the association between passenger flow and OHCA incidence remains unexplored.

Hypothesis:
At train stations, OHCA risk is associated with passenger flow, and patients have better outcomes compared to other public OHCAs.

Aims:
To guide a strategic deployment of AEDs, we aimed to investigate the incidence of OHCA and its association with passenger flow, as well as outcomes after OHCA at train stations nationwide.

Methods:
We included non-EMS witnessed OHCAs from the Danish Cardiac Arrest Registry (2016-2020). Data on stations were obtained from
The Danish State Railways
and
Metro Company
. Using QGIS stations were geocoded as a 100-meter radius from the center of the station, and stations where buffers were not possible due to size or structure polygons, were drawn. Stations were divided into groups based on the number of passengers/day:
1 (0-500), 2 (500-5,000), 3 (5,000-10,000), and 4 (>10,000),
respectively.We used Fisher’s exact test to compare outcomes. We analyzed the incidence rate’s association with passenger flow and the risk ratio using Poisson regression of rates.

Results:
Train stations accounted for 102 (2.3%) of all 4,467 public OHCAs. The incidence rate (IR) and risk ratio (RR) for OHCA were for group 1: IR = 0.02 OHCA/station/year, RR = 1.0 (ref); group 2: IR = 0.07, RR = 4.1 (95%CI 2.3-7.3); group 3: IR = 0.25, RR = 12.7 (95%CI 6.2-25.9); and group 4: IR = 0.34, RR = 16.3 (95%CI 8.6-30.9).OHCAs at train stations were more likely defibrillated by bystanders (28.4% (95% CI 0.20-0.38) vs. 20.4% (95%CI 0.19-0.22), p-value = 0.063), more patients achieved ROSC (56.8% (95% CI 0.47-0.67) vs. 43.8% (95% CI 0.43-0.46), p-value = 0.011) and had a higher survival (45.1% (95% CI 0.35-0.55) vs. 27.0% (95% CI 0.26 - 0.28), p-value <0.001) compared to other public OHCAs.

Conclusion:
The incidence of OHCA at trains station was directly associated with passenger flow, with the busiest stations having a 16-fold higher risk of OHCA than the lowest, making passenger flow an important indicator for AED deployment. OHCAs at train stations had better outcomes than other public OHCAs.
Abstract 351: Novel Quantitative Imaging Biomarkers From Acute Brain CT Using Artificial Intelligence for Predicting Neurological Prognosis in Cardiac Arrest Patients: A Pilot Study
Authors: Nishiyama Kei
Published: December 2023

Background:
Effective use of information extracted from medical images has attracted attention for decision support in primary care of patients with cardiac arrest (CA).

Hypothesis and Aims:
This study aimed to predict the neurological prognosis of patients with cardiac arrest by quantitative imaging biomarkers (QIBs) extracted from acute CT brain images before admission using artificial intelligence.

Methods:
Eighty-six CA patients (good prognosis; Glasgow-Pittsburgh cerebral performance categories [CPC]=1 or 2 at 90 days after the CA : 32 patients, poor prognosis; CPC=3, 4, or 5 at 90 days after the CA : 54 patients) treated at three hospitals between 2017 and 2019 were retrospectively analyzed. None of the CA patients caused by trauma or brain damage were included in the database. The data were divided into training and test data, and the training data were used to select informative QIBs for classification between the good and poor neurological prognosis in this analysis.

Results:
Seven CA patients’ data were excluded from the study due to severe metal and bone artifacts broadly spreading on the brain image, and 1170 QIBs were extracted from whole brain and regional brain interest volumes on CT images of each patient. The QIBs were composed of first-order histogram and texture features and informative QIBs for the classification were selected by feature selection algorithms using the training dataset. The feature corresponding to the gray level having a maximum gradient in the image histogram from the brain region of interest on CT images showed the strongest significant difference between the good and poor neurological prognosis of the test data set with p=0.009 and AUC=0.775 (95% CI; 0.590-0.960).

Conclusions:
We have shown that QIB can be used to predict neurological prognosis in patients with CA. Because this is a pilot study for methodological development and there are limitations in sample size and outcomes, new studies on a larger number of patients are required.
Abstract 376: Comparison of Pre and Post Conditioning With Poloxamer 188 in Rat Model of Severe Hemorrhagic Shock
Authors: Oyama Takuro , Barajas Matthew , Riess Matthias L
Published: December 2023

Background:
Hemorrhagic shock remains a leading cause of morbidity and mortality after trauma. Poloxamer (P) 188, an FDA-approved copolymer-based cell membrane stabilizer, is a nonionic triblock copolymer believed to prevent cellular injury after ischemia and reperfusion. While post conditioning may be used in a broad range of scenarios, pre-conditioning may add improved efficacy in scenarios where hemorrhage can be expected, the peri-operative period. We have previously demonstrated prolonged survival with P188 post-conditioning however without complete rescue, here we hypothesize pre-conditioning would further improve survival.

Methods:
35 male Sprague Dawley rats (564+/-73 g) were anesthetized, ventilated and instrumented. All rats underwent rapid controlled blood loss of 40% estimated blood volume over 30 min, followed by prolonged permissive hypotension for 60 min before re-transfusion of the lost blood to euvolemia and up to 6 hrs of monitoring under general anesthesia. Rats were then randomized to 3 groups: 10 rats received a 0.8 cc iv bolus of 250mg/kg P188 15min before hemorrhage (pre), 12 rats received the same dose of P188 after hemorrhage (post), and 13 control rats only received 0.8 cc vehicle. Primary endpoint was survival time from the start of hemorrhage. Data are median and IQ range; statistics: Kruskal-Wallis and Chi-Square tests, *p<0.05.

Results:
P188 administration immediately after hemorrhage significantly improved median survival time compared to both the pre and control groups [post *245 (49, 314) min vs. control group; 53 (32-60), vs pre; 59 (24-70) min, p = 0.0174, 0.00045, respectively]. However, there was no significant differences in survival time between pre and control grouyps and there were no differences in survival rate at 6 hours (pre; 0% vs post; 8% vs control; 7%).

Conclusion:
A bolus of P188 given immediately after a severe hemorrhagic insult prolonged survival time significantly. However, administration of P188 15 min before hemorrhage did not produce a significant prolongation of survival time.P188 is a highly promising compound whose dose, application timing and application duration in severe hemorrhagic shock require more research.
Abstract 383: Effect of Audiovisual Feedback Device Type on Prehospital Chest Compression Quality During Prehospital Resuscitation
Authors: LEE Stephen Gyung Won G , Kim Tae Han H , Song Kyoung J , Park Jeong Ho , Kim Ki Hong , Choi Yeongho , KIM Minwoo , Hong Kijeong
Published: December 2023

Background:
Real-time audiovisual feedback devices have been implemented to optimize cardiopulmonary resuscitation (CPR) performance during out-of-hospital cardiac arrest (OHCA). Emergency medical service (EMS) personnel perceive different levels of usability regarding feedback device type. The study aimed to evaluate the effect of type of audiovisual feedback device used during prehospital CPR on chest compression quality during prehospital resuscitation.

Method:
Adult OHCA patients who received CPR by EMS personnel utilizing feedback device in Seoul between April 2020 and December 2021 were included. Cases that utilized mechanical chest compression devices were excluded. Feedback devices were classified into two types: sticker-type (S-type) and puck-type (P-type). The quality of chest compressions during prehospital resuscitation was compared based on the feedback device type. The primary outcome assessed was chest compression depth. Subgroup analysis was conducted for cases in which EMS personnel had experience using both types of devices.

Results:
In total, 2,896 OHCA cases were included. 1,596 cases utilized S-type devices and 1,300 cases utilized P-type devices. The median chest compression depth was significantly higher in cases that utilized the S-type device (Median: 5.2, interquartile range (IQR): 4.5-5.8) compared to those that used the P-type device (Median: 4.3, IQR: 3.7-5.0) (P<0.001). In addition, proportion of chest compressions with adequate depth (5-6 cm) was significantly higher in the S-type group, while average chest compression rate and chest compression fraction were higher in the P-type group. Similar findings were observed in the subgroup analysis.

Conclusion:
Difference in chest compression quality parameters were observed during prehospital resuscitation according to type of audiovisual feedback device utilized. Chest compression quality regarding chest compression depth was superior when S-type feedback device was used.
Abstract 394: Epinephrine Administration Before Defibrillation in Children With an Initially Shockable In-Hospital Cardiac Arrest Rhythm
Authors: Swanson Morgan B , Lasa Javier J , Chan Paul S , Morgan Ryan W , Sutton Robert M , Topjian Alexis A , Atkins Dianne L , Haskell Sarah E , Raymond Tia T , Girotra Saket
Published: December 2023

Background:
Contrary to current guidelines, administration of epinephrine before first defibrillation for shockable in-hospital cardiac arrest (IHCA) is common in adults and associated with lower survival. Whether these findings are also present in pediatric IHCA remains unknown.

Methods:
We used 2000-2020 data from the Get With the Guidelines®—Resuscitation registry to identify children (<18 years) with index IHCA due to an initial shockable rhythm of ventricular fibrillation or pulseless ventricular tachycardia and at least 1 defibrillation attempt. Study outcomes were event survival, defined as return of spontaneous circulation for
>
20 minutes, survival to hospital discharge and favorable neurologic survival. Inverse probability of treatment weighting (IPTW) using propensity scores was used to adjust for confounding .

Results:
Among 492 pediatric IHCA index events (median [IQR] age, 7 years [0.75 to 14 years]; 351 [71%] in the ICU), 142 (29%) children with an initial shockable rhythm received epinephrine before defibrillation. Subjects receiving epinephrine before defibrillation had longer times to defibrillation compared to those receiving defibrillation first (median [IQR]: 4 minutes [2 to 8] vs. 1 minute [0 to 2]). Rates of event survival (72.7% vs. 82.8%), survival to hospital discharge (36.4% vs. 47.9%), and favorable neurologic survival (18.9% vs. 33.1%) were lower in the epinephrine before defibrillation group, Table). However, in adjusted analyses using IPTW, epinephrine before defibrillation was not associated with survival outcomes (Table).

Conclusions:
Nearly one in three pediatric IHCA with initial shockable rhythm receives epinephrine before defibrillation in contrast with recommended guidelines. However, unlike adults with IHCA, we did not identify a clear association between epinephrine before defibrillation and survival.
Abstract 405: Characteristics and Care of Pediatric Out-of-Hospital Cardiac Arrest in the National Emergency Medical Services Information System
Authors: Kadish Chelsea B , Gage Christopher , Powell Jonathan , Ulintz Alexander , Wang Henry E , Panchal Ashish
Published: December 2023

Background:
Pediatric out-of-hospital cardiac arrest (OHCA) is an infrequent event with variations in clinical performance in the United States. Recent data on national incidence and treatments provided by Emergency Medical Services (EMS) clinicians during these events is unclear. We sought to characterize the incidence, medications, and procedures performed on children presenting with OHCA.

Methods:
We evaluated EMS responses in the US using 2021 National Emergency Medical Services Information System (NEMSIS) data. We included children (age ≥1 day - 17 years) with 9-1-1 responses. We identified OHCA events by those with reported: 1) cardiac arrest, 2) EMS resuscitation attempt, 3) EMS CPR performance, or 4) EMS defibrillation. We determined the incidence of pediatric out-of-hospital cardiac arrest among EMS responses and evaluated patient demographics (age, sex, race, location, urbanicity) and clinical interventions (medications, airway procedures).

Results:
Among 1.74 million pediatric 9-1-1 responses in 2021, we observed 13,040 OHCA events and an overall incidence of 7.6 per 1,000 pediatric 9-1-1 responses. For OHCA events, the median age was 3 years (IQR 0.33,14); 33% of events occurred in children less than one-year-old and 30% in adolescents aged 13-17. Most patients were male (58%) and events occurred mainly in urban settings (79%) and homes (63%). Of this population, 12% received defibrillation, 41% epinephrine, and 27% an advanced airway (endotracheal intubation or supraglottic airway).

Conclusions:
Pediatric OHCA incidence was low and followed a biphasic pattern by age. As expected in the pediatric population, defibrillation rates were low. One-quarter of patients received an advanced airway. Epinephrine, recommended for all cardiac arrests, was found to be administered in less than half of these events. Further studies are needed to evaluate barriers to optimal OHCA management in pediatric patients in prehospital settings.
Abstract 407: The Efficacy and Frequency of Early Left Heart Catheterization After Out of Hospital Cardiac Arrest Over That Last Decade
Authors: Mathew Shobi , Welch Robert , Swor Robert , Ehrman Robert , Lagina Anthony , O'Neil Brian J
Published: December 2023

Background:
The efficacy of early coronary intervention after return of spontaneous circulation (ROSC) from out of hospital cardiac arrest, (OHCA) is debated. A recent review of the Wayne County, (Mi) CARES dataset from 2014-18 noted that early LHC maintained the strongest correlation to survival to discharge with good neurological outcome, for all-cause OHCA. Though the overall rate of LHC remained relatively stable, there was a sizable reduction in early LHC and a comparable increase in late LHC in those with CPC 1 and 2 at discharge [
12
] Our objective is to utilize the national CARES data to analyze the effect of early LHC on survival with good neurological outcome and to describe the frequency and timing of LHC in OHCA.

Methods:
This observational study included patients enrolled in the national CARES registry from 2013-21. For the outcome of LHC by year, chi square analysis was performed. Outcome was cerebral performance category, (CPC) (good <3 vs. poor
>
3) at hospital discharge. A propensity score (PS) model was constructed using variables predictive of LHC and good outcome to determine probability of LHC. The PS was then used in an inverse weighted random effects logistic regression model to determine the independent effect of early LHC on outcome.

Results:
132,758 individual cases were identified. Median age was 60.3 years (s.d. 16.6), 61.8% were male. Early coronary angiography was performed in 26,999 (20.3%) patients. Patients who underwent early angiography often had shockable rhythms (78.% vs 34%), suffered the OHCA in a public location (36.9% vs 26.1%%), and were witnessed cardiac arrests (80% vs 48%). For the full model the odds ratio for a good outcome after early LHC was 2.54 (95% CI 2.36 - 2.73). Only initial shockable rhythm was more predictive of a good outcome with an OR of 3.9. The proportion undergoing early catheterization declined from 27.6 % to 17.3% from 2013 to 2021; p < 0.0001), though the overall catheterization rate remained the same.

Conclusion:
In patients with OHCA, early left heart catheterization retains a strong association with good neurological outcome at hospital discharge. The use of early left heart catheterization has declined significantly over the last 9 years.
Abstract 415: Standard versus Early Abdominal Counter-Constriction During Circumferential CPR
Authors: Oberdier Matt T , Paradis Aidan , Neri Luca , Paradis Norman
Published: December 2023

Introduction:
Circumferential constriction CPR (CC-CPR) applied by pneumatic vest may be superior to standard sternal compression, and the addition of alternative pumping modalities may further enhance efficacy. Interposed abdominal counterpulsation (IAC-CPR) CC-CPR is one such modality. Early canine studies of IAC reported greater efficacy when the abdominal counterpulsation was started 30% before the thoracic compression, rather than fully counterphase timing as is used clinically. This may be thought of as “Abdominal Preload” IAC (Pre-CPR).

Hypothesis:
Addition of IAC-CPR to CC-CPR may be associated with improved perfusion pressures, and Pre-CPR may be even more effective.

Methods:
We compared CC-CPR to IAC-CPR and Pre-IAC in a porcine model of VF (n=6). In IAC-CPR, the constrictions are fully counterphase. In Pre-IAC, abdominal constriction is initiated 30% before thoracic constriction. Alternating 30 second epochs of each treatment were applied via a circumferential abdominal vest. Aortic (Ao) and Right Atrial (RA) pressures were measured by micromanometer catheters. IAC-CPR and Pre-CPR end-epoch pressures were each compared to preceding CC-CPR end-epoch pressures.

Results:
Addition of IAC-CPR and Pre-IAC to CC-CPR were both associated with similar, significant increases in CPPs. However, the source of these improvements differed (See Table 1). For IAC-CPR, the increase appeared to result from an Ao increase greater than an associated increase in RA. For Pre-CPR, the increase appeared to be solely due to increased Ao.

Limitations:
Small sample. Surrogate biomarkers. Non-human model.

Conclusions:
The addition of pulsatile abdominal counter-constriction to vest CC-CPR may be a promising path to multimodality, regardless of the particulars of cycle timing. We do not confirm earlier observations that Pre-CPR may be superior to IAC-CPR.
Abstract 418: Characteristics of Post-Shock Refibrillation in Out-of-Hospital Cardiac Arrest
Authors: Chen Shujie , Liu Chenguang , Gehman Stacy , Gao Mengqi , Burgett Kevin , Jorgenson Dawn
Published: December 2023

Introduction:
Early defibrillation is critical for out-of-hospital cardiac arrest (OHCA) patients with shockable rhythms. Following successful shocks, refibrillation is common. The present study investigated three outcomes including shock efficacy, refibrillation rate, and refibrillation time (defined as the interval between shock delivery and refibrillation) in OHCA patients.

Methods:
Adult cases treated with Philips SMART Biphasic 150 J shocks from four US EMS agencies were included. The shocks were delivered by professional level HeartStart FR3 AEDs which are more likely to encounter longer patient down time compared to public access AEDs. Two rhythm experts independently annotated shock success, defined as the presence of a non-shockable rhythm for at least 5 seconds (s) after the shock. Successful shocks followed by a CPR period of ≥ 60 s were further annotated with refibrillation time if it occurred. If post-shock outcome could not be determined due to excessive artifact or post-shock data < 5 s, the shock success and/or the refibrillation were annotated as undeterminable. Annotator disagreements were resolved by review with a third rhythm expert to reach consensus.

Results:
A total of 464 shocks from 254 cases were analyzed. Shock efficacy was 87.7% for the first shock and 85.5% for all shocks. Shockable rhythms were successfully terminated at least once in 94.2% of the patients. Following successful shocks, the refibrillation rate was 55.9% for the first shock and 61.0% for all shocks. The median refibrillation time was 32.7 s (range: 5.1-582.4 s). The distribution of the refibrillation time is shown in Figure 1.

Conclusions:
Most patients needed more than one shock mainly due to refibrillation. About 50% of the refibrillations occurred within 30 s, which suggests that identification of early refibrillation for prompt defibrillation may be beneficial.
Abstract 419: Incidence of True Refractory Ventricular Fibrillation in Patients Meeting a Pragmatic Definition of Refractory Ventricular Fibrillation
Authors: Verkaik Bas J , Walker Rob G , Marx Rob , Ekkel Mette M , Taylor Tyson G , Stieglis Remy , van Eeden Vera G , van Schuppen Hans , Chapman Fred W , van der Werf Christian
Published: December 2023

Introduction:
Refractory VF, pragmatically defined as a shockable presenting rhythm that is still observed after three shocks and associated 2-minute CPR cycles, is often encountered in out-of-hospital cardiac arrest (OHCA) and is associated with worse outcomes. A recent clinical trial tested alternative strategies for treating patients meeting this definition of refractory VF. It is unknown how often standard defibrillation truly fails to terminate VF in these patients.

Methods:
Using the prospective AmsteRdam REsuscitation STudies (ARREST) registry of OHCA patients, we examined termination of VF in patients meeting the pragmatic definition of refractory VF between 2016 and 2019. All patients received standard defibrillation. We reviewed ECG waveforms from all AEDs and manual defibrillators to analyze termination of VF to a non-shockable rhythm at five seconds after each of the first 3 shocks. Refibrillation was defined as recurrence of VF after a shock terminated VF.

Results:
Out of 1573 OHCAs with an initial shockable rhythm, we analyzed the 453 cases (29%) that met the pragmatic definition of refractory VF. Median time to first shock was 8.0 (IQR 6.3-9.7) minutes; in 65% an AED was used. The first three shocks terminated VF at least once in 96% of the patients, at least twice in 81%, and all three times in 57%. Altogether, VF was terminated by 78% of all individual shocks. In 4% of patients all three shocks failed to terminate VF (Figure). Median time to refibrillation was 32 (IQR 12-61) seconds. ROSC at any time occurred in 59% of patients; 27% survived to discharge.

Conclusions:
In patients meeting a pragmatic definition of refractory VF, true refractory VF without termination of the shockable rhythm by any of the first three shocks was rare. Instead, VF was successfully terminated by most shocks and recurred during the ensuing CPR cycle. Therefore, the mechanism of benefit from alternative defibrillation strategies in these patients is unclear.
Abstract 420: The Association Between Ventricular Fibrillation Duration and Successful Termination After the First Shock in Witnessed Out-of-Hospital Cardiac Arrest Patients
Authors: Verkaik Bas J , Stieglis Remy , Tan Hanno , van Schuppen Hans , Koster Rudolph W , van der Werf Christian
Published: December 2023

Introduction:
In OHCA patients with an initial shockable rhythm, a longer time interval between onset of VF and the first shock decreases the likelihood of survival. The exact mechanism to explain this decrease is not clear. We investigated the time interval between delay to the first shock and outcomes VF termination, return of organized rhythm (ROOR), ROSC and survival.

Methods:
We studied witnessed OHCA patients with VF as an initial rhythm using the prospective ARREST registry. Patient- and resuscitation data, including time-synchronized AED and manual defibrillator data, were analysed to determine VF termination at 5 seconds after the first shock. Shock delay was defined as the time from initial emergency call till first shock by any defibrillator. Outcomes were rates of termination of VF, ROOR 5 seconds after the first shock, ROSC before transport, and survival to discharge, all in relation to the delay to the first shock. A logistic regression corrected for age, sex and basic life support before EMS arrival was used to analyse the association between VF duration and outcomes.

Results:
A total of 3676 cases were analysed. VF termination rates declined from 95% when the first shock was delivered <2 minutes after the call to 75% when delivered after >16 minutes (Figure 1). Rates of ROOR (49% to 23%), ROSC before transport (86% to 33%), and survival to discharge (79% to 23%) all declined significantly. Every additional minute in VF was associated with a 9% increased odds of failure to terminate VF (OR 1.09 [95% CI 1.07-1.12]), a 7% reduced odds of ROOR (OR 0.93 [95% CI 0.91-0.95]), a 12% reduced odds of acquiring ROSC before transport (OR 0.88 [95% CI 0.86-0.90]), and a 15% reduced odds of surviving to discharge (OR 0.85 [95% CI 0.83-0.87]).

Conclusions:
Every additional minute of delay to the first shock was associated with significant decreases in rates of VF termination, ROOR, and ROSC during transportation. This may explain the worse outcomes in patients with a long delay to defibrillation.
Abstract 426: The Rural Experience of Cardiac Arrest in Maine: Geography, EMS Access, and Social Determinants of Health
Authors: May Teresa L , Stoddard Henry , Daley Alison , Sholl Matthew , Oko Jason , Ryzhov Sergey V , deKay Joanne T , Gagnon David , Riker Richard R , Seder David B
Published: December 2023

Introduction:
Resuscitation resources and outcomes differ between rural and urban areas, largely due to patient risk factors and limited emergency medical service (EMS) resources. The current definitions of rural areas are inconsistent and do not encompass all the factors that may affect post-resuscitation care, such as healthcare access, and social determinants of health (SDOH).

Hypothesis:
In addition to rurality category, measures of healthcare access and SDOH further explain variability in cardiac arrest outcomes across the state of Maine.

Goals:
Evaluate the difference in model performance in determining survival at three months, using EMS-data, measures of geographic rurality, healthcare access, and SDOH.

Approach:
We utilized Maine EMS & Fire Information Systems to identify non-traumatic out-of-hospital cardiac arrests in Maine from 2018-2021. We merged this data with state Center for Disease Control data to determine 30-day survival. Risk adjusted models were developed and measures of healthcare access and SDOH were added for all patients and for a cohort of patients who were transported to an Emergency Department (ED). We measured model performance and compared models using likelihood ratio tests.

Results:
Inclusion criteria was met in 4,277 patients and 1,167 (27%) patients were transported to an ED. After risk adjustment, the best performing model included Rural Urban Commuting Area (p=0.083), time from arrest to highest level of EMS provider (p<0.001) and Area Deprivation Index (p=0.01). For patients transported to EDs, the best performing model included population per square mile (p=0.001), time from arrest to highest level of EMS provider (p=0.041) and census tract with high school education or greater (p<0.001). In both cohorts, the model with all three factors and other risk adjustment was superior to the baseline and models with any individual factor (likelihood ratio test p<0.05).

Conclusions:
The addition of rurality measures to cardiac arrest characteristics improves model association with good outcome and the addition of markers of EMS response and SDOH explained additional variability. These factors should be considered in combination when evaluating outcome disparities among patients with cardiac arrest.
Nonsense Variant PRDM16-Q187X Causes Impaired Myocardial Development and TGF-β Signaling Resulting in Noncompaction Cardiomyopathy in Humans and Mice
Authors: Sun Bo , Rouzbehani Omid M.T. , Kramer Ryan J. , Ghosh Rajeshwary , Perelli Robin M. , Atkins Sage , Fatahian Amir Nima , Davis Kathryn , Szulik Marta W. , Goodman Michael A. , Hathaway Marissa A. , Chi Ellenor , Word Tarah A. , Tunuguntla Hari , Denfield Susan W. , Wehrens Xander H.T. , Whitehead Kevin J. , Abdelnasser Hala Y. , Warren Junco S. , Wu Mingfu , Franklin Sarah , Boudina Sihem , Landstrom Andrew P.
Published: December 2023

BACKGROUND:

PRDM16 plays a role in myocardial development through TGF-β (transforming growth factor-beta) signaling. Recent evidence suggests that loss of PRDM16 expression is associated with cardiomyopathy development in mice, although its role in human cardiomyopathy development is unclear. This study aims to determine the impact of PRDM16 loss-of-function variants on cardiomyopathy in humans.

METHODS:

Individuals with
PRDM16
variants were identified and consented. Induced pluripotent stem cell–derived cardiomyocytes were generated from a proband hosting a Q187X nonsense variant as an in vitro model and underwent proliferative and transcriptional analyses. CRISPR (clustered regularly interspaced short palindromic repeats)-mediated knock-in mouse model hosting the
Prdm16

Q187X

allele was generated and subjected to ECG, histological, and transcriptional analysis.

RESULTS:

We report 2 probands with loss-of-function
PRDM16
variants and pediatric left ventricular noncompaction cardiomyopathy. One proband hosts a PRDM16-Q187X variant with left ventricular noncompaction cardiomyopathy and demonstrated infant-onset heart failure, which was selected for further study. Induced pluripotent stem cell-derived cardiomyocytes prepared from the PRDM16-Q187X proband demonstrated a statistically significant impairment in myocyte proliferation and increased apoptosis associated with transcriptional dysregulation of genes implicated in cardiac maturation, including TGF-β–associated transcripts. Homozygous
Prdm16

Q187X/Q187X

mice demonstrated an underdeveloped compact myocardium and were embryonically lethal. Heterozygous
Prdm16

Q187X/WT

mice demonstrated significantly smaller ventricular dimensions, heightened fibrosis, and age-dependent loss of TGF-β expression. Mechanistic studies were undertaken in H9c2 cardiomyoblasts to show that PRDM16 binds TGFB3 promoter and represses its transcription.

CONCLUSIONS:

Novel loss-of-function
PRDM16
variant impairs myocardial development resulting in noncompaction cardiomyopathy in humans and mice associated with altered TGF-β signaling.
Utility of Left and Right Ventricular Strain in Arrhythmogenic Right Ventricular Cardiomyopathy: A Prospective Multicenter Registry
Authors: Namasivayam Mayooran , Bertrand Philippe B. , Bernard Samuel , Churchill Timothy W. , Khurshid Shaan , Marcus Frank I. , Mestroni Luisa , Saffitz Jeffrey E. , Towbin Jeffrey A. , Zareba Wojciech , Picard Michael H. , Sanborn Danita Yoerger ,   on behalf of the North American ARVC Registry
Published: December 2023

BACKGROUND:

Imaging evaluation of arrhythmogenic right ventricular cardiomyopathy (ARVC) remains challenging. Myocardial strain assessment by echocardiography is an increasingly utilized technique for detecting subclinical left ventricular (LV) and right ventricular (RV) dysfunction. We aimed to evaluate the diagnostic and prognostic utility of LV and RV strain in ARVC.

METHODS:

Patients with suspected ARVC (n = 109) from a multicenter registry were clinically phenotyped using the 2010 ARVC Revised Task Force Criteria and underwent baseline strain echocardiography. Diagnostic performance of LV and RV strain was evaluated using the area under the receiver operating characteristic curve analysis against the 2010 ARVC Revised Task Force Criteria, and the prognostic value was assessed using the Kaplan-Meier analysis.

RESULTS:

Mean age was 45.3±14.7 years, and 48% of patients were female. Estimation of RV strain was feasible in 99/109 (91%), and LV strain was feasible in 85/109 (78%) patients. ARVC prevalence by 2010 ARVC Revised Task Force Criteria is 91/109 (83%) and 83/99 (84%) in those with RV strain measurements. RV global longitudinal strain and RV free wall strain had diagnostic area under the receiver operating characteristic curve of 0.76 and 0.77, respectively (both
P
<0.001; difference NS). Abnormal RV global longitudinal strain phenotype (RV global longitudinal strain > −17.9%) and RV free wall strain phenotype (RV free wall strain > −21.2%) were identified in 41/69 (59%) and 56/69 (81%) of subjects, respectively, who were not identified by conventional echocardiographic criteria but still met the overall 2010 ARVC Revised Task Force Criteria for ARVC. LV global longitudinal strain did not add diagnostic value but was prognostic for composite end points of death, heart transplantation, or ventricular arrhythmia (log-rank
P
=0.04).

CONCLUSIONS:

In a prospective, multicenter registry of ARVC, RV strain assessment added diagnostic value to current echocardiographic criteria by identifying patients who are missed by current echocardiographic criteria yet still fulfill the diagnosis of ARVC. LV strain, by contrast, did not add incremental diagnostic value but was prognostic for identification of high-risk patients.