bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 15893: Etiologies for Hospitalizations and in Hospital Mortality in Patients With Atrial Fibrillation: Insight From National Inpatient Sample Database
Authors: Yilmaz Mahir , Hammo Hasan , Sana Muhammad Khawar , DeAngelo Sean , Sharma Bharosa , Usman Muhammad , Almani Muhammad Usman , ASEMOTA IRIAGBONSE
Published: June 2023

Introduction:
Atrial fibrillation is a common clinical syndrome that leads to high volumes of hospitalizations and in hospital mortality. Previous studies have attempted to characterize the various reasons for the high rates of morbidity and mortality associated with atrial fibrillation. Our study aimed to utilize large database information to identify the most common indicators for and cause of death in patients with atrial fibrillation.

Methods:
Using the National Inpatient Sample database, we analyzed atrial fibrillation hospitalizations during the years 2016-2019 and categorized reasons for hospitalization and in-patient mortality using the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10).

Results:
We identified a total of 18,084,144 hospitalizations with atrial fibrillation as the principle or secondary diagnosis ICD-10 code. The most common systems involved were cardiovascular (37%), respiratory (10%), and infectious (10%). Specifically, the leading cause for hospitalization was heart failure (10%) followed by atrial fibrillation (9%) and sepsis (7%), There was a total of 848,579 cases of in-hospital mortality in patients with atrial fibrillation during this period. The most common reason for mortality was sepsis (26%), followed by acute respiratory failure (5%), heart failure (5%), non ST elevation myocardial infarction (NSTEMI) (2%), and pneumonia (1%).

Conclusion:
This study represents the most recent nationwide data on causes for hospitalization and mortality in patients with atrial fibrillation across the United States. In our analysis, we found that the most common cause of hospitalization was attributed to cardiovascular disease, specifically heart failure, while sepsis was the most common cause of inpatient mortality. A better understanding of why patients are hospitalized may lead to changes in practice to prevent admissions as well as in-hospital management to ultimately prevent death.
Abstract 15895: Causes and Predictors of 30-Day Readmission After Implantable Cardioverter/Defibrillator Insertion in Heart Failure Patients: Insight From the National Readmissions Database
Authors: Kodali Mouna , Atluri Ramtej , Yalamanchili Sreeram , Vardar Ufuk , Shoura Sami , Velagapudi Sujitha
Published: June 2023

Introduction:
Implantable Cardioverter/Defibrillator (ICD) insertion in heart failure (HF) patients with ejection fraction below 30% and at least 40 days post-infarction is rapidly becoming commonplace. Given the high prevalence of ICD insertions in HF patients with reduced ejection fraction (HFrEF) we aimed to analyze the rates and causes of readmissions in this specific population.

Methods:
We utilized the National Readmission Database from 2018 to identify hospitalized adults with HF who underwent ICD insertion. We included those who were readmitted within 30 days after the index admission. We excluded elective and traumatic admissions. A multivariate cox regression model was used to identify independent predictors of readmission.

Results:
During the study period, 283,539 hospitalized patients with HF who underwent ICD insertion were discharged alive. Within 30-days from discharge, 46,537 (16.4%) were readmitted. The top three causes of readmission were heart failure (35.2%), sepsis (5.26%), and ventricular tachycardia (4%). Readmitted patients were more likely to be discharged to nursing facility (45% vs 38%; p<0.001), had higher rates of Medicare/Medicaid (89.2% vs 78.7%; p<0.001) and annual income < $44,000 (35.7% vs 33%; p<0.001). In-hospital mortality (5.6% vs 3.4%; p<0.001) was higher during readmission.
Figure 1
shows the Forrest plot of multivariate analysis of independent factors associated with readmissions.

Conclusions:
We identified social and clinical predictors of readmission after ICD insertion in those with HF such as household income, discharge to a nursing home, renal/lung disease, and intubation during their index admission. Healthcare systems should use this data to target modifiable factors to prevent readmissions as this can help ease the burden placed on the resources of the American healthcare system and improve clinical outcomes for patients.
Abstract 172: Utility Of Cerebrospinal Fluid Lactate To Predict Neurological Prognosis In Patients With Out Of Hospital Cardiac Arrest Undergoing Target Temperature Management
Authors: You Yeonho , Kang Changshin , Ahn Hong Joon , Park Jung Soo , Jeong Won-joon , Min Jinhong , In Yong
Published: June 2023

Utility of cerebrospinal fluid lactate to predict neurological prognosis in patients with out of hospital cardiac arrest undergoing target temperature managementLactate is a predictor of poor neurological prognosis in patients with OHCA undergoing TTM.However, CSF lactate is independent on serum lactate, and has rapid turn around time. Therefore, we investigated the prognostic value of CSF lactate, measured every 2 h for 24 h after ROSC and the incidence of mitochondrial dysfunction (MD) and ischaemia with increased CSF lactate in the groups with good and poor neurological prognosis.This was a prospective observational study conducted from March 2021 to April 2022 (**** IRB 2020-04-051). All patients were monitored with aEEG. Serum and CSF were obtained using a radial arterial and a lumbar catheter. 22 patients were required through sample size calculation. The comparison of lactate between the two groups was evaluated using the generalized estimating equation. The AUROC was used to identify the prognostic values of lactate (Fig. 1, Table 1). Parameters measured immediately, and 24 h after ROSC were not different between the two groups (Table 2). CSF lactate level was higher in the group with poor neurological prognosis, and CSF lactate showed better performance in predicting poor neurological prognosis, even after 6 h post ROSC (Table 3, 4, Fig. 2). Additionally, the neurological prognosis was poor when MD or ischaemia in brain persisted more than 16 h after ROSC (Fig. 3).This study demonstrated that CSF lactate was a valuable tool in predicting poor neurological prognosis, and cases in which MD or ischaemia in the brain persisted more than 16 h after ROSC had poor outcome.
Abstract 180: Impact Of Hot Debriefing Programs On Pediatric Cardiopulmonary Resuscitation Quality And Outcomes
Authors: Jani Priti , Sweberg Todd , Dewan Maya , Tegtmeyer Ken , Mullan Paul , Griffis Heather , Zhang Xuemei , Niles Dana , Nadkarni Vinay M , Wolfe Heather ,   Pediatric Resuscitation Quality Collaborative (pediRES-Q) Investigators
Published: June 2023

Introduction:
Successful cardiopulmonary resuscitation (CPR) outcomes rely on AHA guideline compliant chest compressions (CC). Resuscitation teams struggle to achieve these CPR metrics. Cold debriefing has led to higher quality CPR and improved patient outcomes. The impact of hot debriefing (HD) on CPR quality and patient outcomes is unknown. We sought to evaluate the association of HD on CPR quality and patient outcomes.

Methods:
Retrospective cohort of in-hospital cardiac arrests (IHCA), 0 to 18yo with complete quantitative CC metrics in the pediRES-Q database (1/2018 - 3/2021). We investigated exposure to HD, defined as hospital HD rate >50% in the 12 months prior to the CPR event, with AHA compliant CPR (CC fraction (CCF) ≥0.80, CC rate (CCR) 100-120/min, and CC depth (CCD) <1yo ≥3.4 cm, 1-8yo ≥4.4 cm, >8yo 4.5≥6.6 cm). HD vs. non-HD events by CPR quality were compared via Chi-square or Wilcoxon rank sum tests and stratified by age. For index events, we evaluated return of circulation (ROC), survival to hospital discharge (SHD) and favorable neurologic outcome (Pediatric Cerebral Performance Category score of 1, 2, or no change from baseline). Multivariable logistic regressions with a Generalized Estimating Equation method, adjusted for age group, arrest duration, initial rhythm, illness category, and site clustering.

Results:
We evaluated 515 IHCA events stratified by HD exposure (221 w and 294 wo) and age. Across age ranges, there was no difference in CCD or CCF between groups. Median CCR was lower in HD exposure groups: <1yo, 110 vs 117 (p <0.001), 1-8yo, 110 vs 117 (p <0.001) and 8-<18yo, 110 vs 115 (p =0.003). There was no difference in compliance with a composite of CCF + CCR + CCD. The composite CCR + CCF had increased compliance in the HD exposure groups: <1yo, 37% (34 of 92) vs 21% (21 of 102) (p = 0.02), 1-8yo, 38% (27 of 72) vs 23% (26 of 111) (p = 0.05) and 8-<18yo, 42% (24 of 57) vs 25% (20 of 81) (p = 0.04). To assess patient outcomes, we evaluated 917 index arrests (255 w HD exposure and 662 wo). On multivariable analysis, no significant difference was found for ROC, SHD or favorable neurologic outcome by HD exposure.

Conclusion:
Pediatric IHCA events with HD exposure demonstrated improved CPR metrics for CCR and CCF. No association was identified for patient level outcomes.
Abstract 192: The Role Of Serum Vitamin E As A Biomarkers For Traumatic Brain Injury: Multi-center Prospective Cohort Study
Authors: Park Gwan J , Song Sunjin , Kim Solki , Lee Jungju , Kim Youngmin , Chai HYunseok , Kim Sangchul
Published: June 2023

Background:
Traumatic brain injury (TBI) is a major public health problem with high mortality and disability. Vitamin E, one of the antioxidants for the treatment of TBI, has not been sufficiently evaluated for predicting the long-term prognosis after TBI. This study aimed to evaluate the prognostic value of vitamin E on clinical outcomes of TBI patients.

Methods:
A multi-center prospective cohort study was conducted in 5 university hospitals between 2018 and 2020 in Korea. All adult patients who were under 65 years of age and who visited the ED using an ambulance for head trauma were eligible. Primary and secondary outcomes were poor neurological outcome (Glasgow outcome scale (GOS) 1-4) and 1-month mortality after hospital discharge. We calculated the adjusted odds ratios (AORs) of the vitamin E for related outcomes adjusting for potential confounders.

Results:
Among 237 eligible TBI patients, 75 (31.6%) were classified into the poor neurological outcome group. Vitamin E level below the reference range was more observed in the poor neurological outcome group (p-value 0.04). In a univariate analysis, vitamin E depletion group showed significant higher 1-month mortality (ORs (95% CI): 5.52 (1.09-27.93)). However, there was no benefit in 1-month mortality after adjusting for confounders (adjusted ORs (95% CI): 1.57 (0.20-12.27)). And there was no significant difference in 1-month GOS between the two groups (ORs (95% CI): 2.75 (0.79-9.52)).

Conclusion:
Low level of serum vitamin E at ED arrival was associated with poor neurological outcome following TBI. There was only a benefit in 1-month mortality in a univariate analysis and no significant difference in 1-month mortality and 1-month GOS after adjusting for confounders.
Abstract 197: Location, Location, Location! Association Of Success In Transthoracic Echocardiography Image Acquisition With Location During Cardiopulmonary Resuscitation.
Authors: Haddad Essaihi Ghania , Jafari Daniel , Owens Casey , Ellspermann Robert , Li Timmy , cohen allison , Becker Lance B , Rolston Daniel
Published: June 2023

Introduction:
Currently, no consensus exists regarding the ideal location for obtaining a transthoracic echocardiography (TTE) image during cardiopulmonary resuscitation (CPR). Of the three common locations, sub-xiphoid (SX), parasternal (PS) and apical (AP), the SX is most frequently used in cardiac arrest (CA) to avoid interfering with CPR. The recent adoption of mechanical chest compression devices may have led to increased use of alternate locations. We aim to assess the association between successful TTE image acquisition and the locations, also to compare the duration of CPR interruptions at each location.

Hypothesis:
We hypothesized that PS location will have a higher success rate compared to SX, but not a longer CPR interruption time.

Methods:
This is a retrospective study of all video-recorded non-traumatic, CA patients ≥18 years old in a quaternary care Emergency Department (ED) from 08/07/2019 to 05/18/2022 where an intra-arrest TTE was performed. Video recordings of cardiac arrest patients were reviewed by 2 physicians with years of experience and a well-established process. Successful image acquisition was defined as 1) visualization of the heart on the ultrasound machine or 2) clinicians verbalizing visualization in the video recording. Chi-square and Kruskal-Wallis tests were performed to compare the success rates and duration of CPR interruptions based on TTE locations. Our health system’s Institutional Review Board approved the conduct of this study.

Results:
A total of 59 patients yielded a combined 154 video recorded TTE attempts 90 (58.4%) SX, 56 (36.4%) PS, and 8 (5.2%) AP. Median age was 81 years, 50.8% female, 81.4% non-shockable initial rhythm, and 89.8% were receiving mechanical CPR. Because there were only 8 AP attempts, PS and SX were the only locations analyzed. PS was successful in 89.3% (68 of 90) compared to 75.6% (50 of 56) for the SX (p=0.04). The median duration of interruptions for PS was 17.5 seconds (IQR: 12.0, 22.0) compared to 15 seconds (IQR: 11.0, 24.0) for SX (p=0.5).

Conclusion:
During CPR, PS location for TTE image acquisition is associated with higher success when compared to SX. However, the median CPR interruption times are not significantly different.
Abstract 199: Femoral Artery Doppler Ultrasound Blood Flow Patterns Predict Intrinsic Pulsatility In Cardiac Arrest Patients Receiving Active Chest Compressions
Authors: Rolston Daniel M , Nello Alexander V , Li Timmy , Jafari Daniel , Becker Lance B , Owens Casey , Haddad Essaihi Ghania , Cohen Allison L
Published: June 2023

Introduction:
Pulse detection requires chest compression interruption, which is associated with poor outcomes in cardiac arrest. Currently no modality can reliably identify return of spontaneous circulation with ongoing chest compressions.

Hypothesis
We hypothesized that patients with intrinsic pulsatility have anterograde dominant blood flow (ADF) on arterial Doppler ultrasound; whereas those with intrinsic pulselessness have bidirectional blood flow moving antero/retrograde during chest compression/decompression.

Methods:
We conducted a prospective, diagnostic accuracy study on a convenience sample of adult Emergency Department (ED) cardiac arrest patients with a femoral arterial line in place. Immediately prior to a pulse check, pulsed-wave Doppler ultrasound of the common femoral artery was performed during active chest compressions. Bidirectional flow was present when the anterograde flow waveform was equal in peak systolic velocity to the retrograde flow waveform. All other Doppler waveforms were ADF. A pulse was present when there was an arterial line waveform. Sensitivity, specificity, and accuracy of ADF versus bidirectional flow for predicting pulsatility was assessed.

Results:
We enrolled 42 patients and performed 104 pulse checks: a pulse was present for 73 (70.2%) and absent in 31 (29.8%). ADF was present in 82 (78.9%) and bidirectional flow was present in 22 (21.2%). Sensitivity of ADF for detecting a pulse was 95.9% (95% CI: 91.3%-100.0%). Specificity of bidirectional flow for detecting pulselessness was 61.3% (95% CI: 44.1-78.4%) and accuracy was 85.6% (95% CI: 77.3-91.7%). Patients with ADF have 36.9 times the odds of having an arterial line pulse compared with patients with bidirectional flow (OR: 36.9; 95% CI: 9.5-144.4).

Conclusion:
In ED cardiac arrest patients, ADF on Doppler ultrasound has high sensitivity for detecting an arterial line pulse. Further studies are needed to further evaluate this novel finding.
Abstract 216: Association Between Trajectories Of End-tidal Carbon Dioxide And Return Of Spontaneous Circulation Among Emergency Department Patients With Out-of-hospital Cardiac Arrest: A Retrospective Analysis Of A Prospective Registry
Authors: WANG CHIH-HUNG , Lu Tsung-Chien , Kah Meng Chong , Chou Eric H , Tsai Chu-Lin , HUANG CHIEN-HUA , Huei-Ming Matthew H , Chen Wen-Jone
Published: June 2023

Introduction:
The level of end-tidal carbon dioxide (EtCO
2
) reflects the blood flow generated by cardiopulmonary resuscitation (CPR). Static EtCO
2
parameters, such as average EtCO
2
levels, has been reported to be associated with outcomes following out-of-hospital cardiac arrest (OHCA).

Hypothesis:
Distinct trajectories of EtCO
2
during CPR was associated with OHCA outcomes.

Methods:
This was a retrospective analysis of a prospectively collected database on patients with OHCA who had been resuscitated in the emergency department of a tertiary medical center between 2015 and 2020. Adult patients with ≥3 measurements of EtCO
2
were included. The primary outcome was the return of spontaneous circulation (ROSC). Group-based trajectory modelling was used to identify the EtCO
2
trajectories. Multivariable logistic regression analysis was performed to evaluate the association between EtCO
2
trajectories and ROSC. The predictive performance of the EtCO
2
trajectories was assessed using the area under the receiver operating characteristic curve (AUC).

Results:
The study comprised 655 patients with OHCA. In the primary analysis, three distinct EtCO
2
trajectories, including 10-mmHg, 30-mmHg, and 50-mmHg trajectories, were identified. Compared with the 10-mmHg trajectory, both 30-mmHg (odds ratio [OR]: 4.66, 95% confidence interval [CI]: 3.15-6.90) and 50-mmHg (OR: 7.58, 95% CI: 4.30-13.35) trajectories were associated with a higher likelihood of ROSC. In a sensitivity analysis of excluding EtCO
2
measured before tracheal intubation or after sodium bicarbonate administration, the predictive ability of the identified EtCO
2
trajectories remained. As a single predictor of ROSC, EtCO
2
trajectories had an acceptable discriminative performance (AUC: 0.69, 95% CI: 0.66-0.73).

Conclusion:
Three distinct EtCO
2
trajectories during CPR were identified and significantly associated with OHCA outcomes, which may assist in guiding the ongoing resuscitation efforts.
Abstract 248: Current Status Of In-hospital Cardiac Arrest And Issues Of Collecting Data Using The Latest In-hospital Utstein-style Reporting Templates
Authors: Kanayama Yu , Kiguchi Takeyuki , Nishiyama Chika , Morita Takashi
Published: June 2023

[Background]:
The outcome of in-hospital cardiac arrest has improved over the past decade, although the survival rate is still approximately 25%. The in-hospital Utstein-style reporting templates were international standard template for in-hospital cardiac arrest, with items to be substantially revised in 2019, with recommendations for standardization of records to allow objective comparisons. The aim of this study is to analyze the current status of in-hospital cardiac arrest in our hospital, and to clarify the issues in collecting the data using the in-hospital Utstein-style reporting templates.

[Methods]:
We collected the reports of 3 years in-hospital cardiac arrests occurred between April 2019 and March 2022 in our hospital. We described all reported items and their proportion (Patient, Pre-event, Cardiac arrest process, Post-resuscitation process, and Outcome), and calculated the missing rate of each item.

[Results]:
A total of 106 cases during the study period, and all reports were submitted by nurses. The median age was 74 years old (IQR: 64-81), 60.4% were male, 76.4% of cases were witnessed, chest compressions were 67.9%, and shock delivered were in 5.9%. The initial shockable rhythm was in 15.1% of cases (Table). Some items had missing data or invalid responses. Date and time of event, initial rhythm, the time of first shock delivered, and 30 days outcome had missing data (rate of missing 33%, 13.2%, 44.4%, and 80.7%, respectively), which were core items of the latest in-hospital Utstein-style reporting templates. Patient category, post-resuscitation process, reason for CPR stopped, and neurological outcome at 30 days were not measured.

[Conclusions]:
The high rate of missing data is considered that the nurses may not understand the meaning of the items, and suggested the need for education of nurses who submit reports.
Abstract 269: Comparison Of Coronary Anatomy And Percutaneous Coronary Intervention Between Patients Undergoing Conventional And Extracorporeal Membrane Oxygenation Resuscitation
Authors: Franco Danilo , Goslar Tomaz , Radsel Peter , De Luca Nicola , Barbato Emanuele , Noc Marko
Published: June 2023

Introduction:
Because reestablishment of spontaneous circulation (ROSC) is frequently not achieved by conventional cardiopulmonary resuscitation (C-CPR), selected patients undergo resuscitation with extracorporeal membrane oxygenation (E-CPR). If coronary cause is suspected, coronary angiography (CAG) and percutaneous coronary intervention (PCI) are performed.

Hypothesis:
Coronary anatomy in E-CPR patients is more complex. Despite decreased and retrograde aortic blood flow, PCI is feasible and successful.

Methods:
Forty-three consecutive E-CPR patients undergoing immediate CAG admitted between August 2013 to May 2022 were matched by sex and age with 43 patients with ROSC after C-CPR.

Results:
Except for increased body mass index (28.9 ± 4.6 vs 26.3 ± 2.7; p=0.002) and more smoking (79% vs 58%; p=0.021) in E-CPR group
,
there was no significant differences in patient characteristics. Arrest was witnessed in 100% in E-CPR and 93% in C-CPR (p=0.078), basic life support was performed in 100% and 84% (p=0.006) and initial shockable rhythm was present in 63% and 82% (p=0.054), respectively. Multivessel disease (60.4% vs 32.5%) and chronic total occlusion (27.9% vs 9.3%) were more prevalent in E-CPR group
(Table).
There was no difference in the incidence and distribution of the acute culprit lesion present in >90%. Syntax score was significantly increased in E-CPR group. E-CPR patients received more stents (2.08 vs 1.38/patient) with increased total length (49.3 vs 27.7 mm). There was no significant difference in final TIMI 3 (88.9% vs 97.4%). Residual Syntax score remained increased in E-CPR group.

Conclusion

E-CPR patients have more extensive chronic coronary disease without significant difference in acute culprit lesion. More complex anatomy may be, in the setting of comparable initial resuscitation, responsible for

C-CPR failure. PCI in E-CPR is successful but more complex with increased residual disease burden.
Abstract 274: Identifying Target Populations For Extracorporeal Cardiopulmonary Resuscitation Among Patients With Refractory Out-of-hospital Cardiac Arrest Using Machine Learning
Authors: Osawa Itsuki , Hirayama Ichiro , Hayakawa Mineji , Shimada Yuichi J , Doi Kent
Published: June 2023

Introduction:
Extracorporeal cardiopulmonary resuscitation (ECPR) can be used on patients with out-of-hospital cardiac arrest (OHCA) when the cause is potentially reversible. However, little is known about the optimal target populations for ECPR among those with refractory OHCA.

Methods:
We retrospectively analyzed nationwide OHCA registry data on 57,754 patients from 93 hospitals in Japan, 2014-2019. We identified 1,273 patients having a witness or initially shockable rhythms with refractory OHCA of presumed cardiac origin without return of spontaneous circulation after >3 doses of adrenaline administration and defibrillations when necessary at the emergency department (ED). We used the causal forest—a machine learning method to estimate heterogeneous treatment effects—to determine individual treatment effects of ECPR on a favorable 30-day neurologic outcome defined as the Cerebral Performance Category scale of 1 or 2, adjusting for confounders (e.g., age, sex, initial cardiac rhythms, and laboratory data). We compared patient characteristics in each quintile of individual ECPR effects to identify potential determinants of ECPR effects in patients with refractory OHCA. Finally, to determine optimal targets of ECPR, we evaluated how ECPR effects could vary depending on patient characteristics.

Results:
We found that the treatment effects of ECPR on a favorable neurologic outcome were heterogeneous (top 20% vs. others, 0.15 vs. 0.00; p<0.001) (
Figure 1
). The key determinants of ECPR effects were initial cardiac rhythms on the emergency medical service (EMS) and at ED arrival, regardless of EMS transport time or laboratory data. In addition, ECPR effects varied depending on the information on ED arrival (i.e., witness, bystander CPR, and initial cardiac rhythms) (
Figure 2
).

Conclusion:
Among patients with refractory OHCA, information available on arrival at the ED could effectively identify patients who may particularly benefit from ECPR.
Abstract 293: Swedish Emergency Medical Dispatch Centres Ability To Answer And Manage Out Of Hospital Cardiac Arrest Calls In Accordance With The American Heart Association Performance Goals
Authors: Byrsell Fredrik , Claesson Andreas , Jonsson Martin , Ringh Mattias , Svensson Leif , Nordberg Per , Forsberg Sune , Hollenberg Jacob , Nord Anette
Published: June 2023

Background:
In witnessed OHCA each minute of delay to CPR reduce the probability of survival. Thus, Emergency Medical Dispatch Centres (EMDC) ability to rapidly answer the emergency call and dispatch EMS is crucial. The American Heart Association (AHA) states that the goal of public safety answering points in a high performing system is to answer OHCA calls within 10 seconds (s) and dispatch the first EMS unit within 60 s.

Aim:
The aim of the study was to 1) describe the EMDC call answer delay and 2) time to dispatch of the first EMS unit in OHCA calls in the region of Stockholm, during 10 years in accordance with the AHA goals for OHCA call handling. We also aimed to 3) investigate the effect of “late responders” on 30-day survival.

Method:
This is an observational study based on OHCA data from the region of Stockholm, Sweden, between year 2012 to 2021. Data was collected from the Swedish Registry for Cardiopulmonary Resuscitation (SRCR) and SOS Alarm AB database.

Results:
During the 10-year period, the EMDC answered a total of 12 298 calls with a corresponding OHCA-record in the SRCR. Complete data was available in 11 484 calls (93%) which were included in the analysis. Of these, 62% (n=7127) of OHCA calls were answered within 10 s, 20% (n=2306) in 10-20 s and 18% (n=2051) above 20 s. The median delay was 7.3 s [IQR 3.3, 15.1]. Dispatch of the first EMS unit was performed within 60 s in 9% (1053 of 11470), 23% (2640 of 11470) between 60-90 s and 68% (7777 of 11470) above 90 s, with a median delay of 114.5 s [IQR 81.4, 168.6]. Differences in call answer delay and time to dispatch of the first EMS unit over the 10-years are presented in Figure 1. Survival at 30-days was 11% (109 of 990) when EMS was dispatched within 60 s, 8.7% (215 of 2459) in 60-90 s and 10.3% (746 of 7210) above 90 s.

Conclusion:
In the region Stockholm the majority of emergency calls concerning OHCA were answered within the high performance system goal of 10 seconds. Additional effort is needed to achieve the 60 second goal for dispatch of the first EMS unit.
Abstract 304: Cerebral Near-infrared Spectroscopy During Pediatric In-hospital Cardiac Arrest: A Multicenter, Observational Study
Authors: ESANGBEDO IVIE , Rajapreyar Prakadeshwari , Kirschen Matthew , Niles Dana , Je Sangmo , Topjian Alexis A , Nadkarni Vinay M , Raymond Tia T
Published: June 2023

Introduction:
Cerebral regional oxygen saturation (crS0
2
) measured by near-infrared spectroscopy (NIRS) during CPR is associated with outcomes in adults, but there is limited pediatric data.

Hypothesis:
Median crSO
2
during pediatric in-hospital cardiac arrest (IHCA) is associated with return of spontaneous circulation (ROSC) and survival to hospital discharge (SHD).

Methods:
Pediatric IHCA events from 2015-2022 with ≥ 1min CPR and intra-arrest crS0
2
reported by 3 sites in the pediRES-Q registry were included. ROSC was defined as return of spontaneous circulation for ≥ 20 mins without ECMO. We analyzed the association of ROSC for all events and SHD for index events only with median crS0
2
and percent crS0
2
measurements above
a priori
thresholds during 1) the entire event, 2) the first 5 mins, and 3) the final 5 mins by Fisher’s exact test, Wilcoxon rank sum test, and multivariable logistic regression with Firth bias correction.

Results:
There were 106 IHCA events in 81 patients. Median age was 0.3 yrs [0.06,0.85], 43% had cyanotic heart disease, and SHD in 61% (49/81). For all events, median CPR duration was 8 mins [3.25, 32] and ROSC was achieved in 62% (66/106). Higher median crSO
2
for the entire event, the first 5 mins, and the last 5 mins was significantly associated with ROSC and SHD (Table). Events with ROSC had significantly higher percent crS0
2
measurements ≥ 30% and 40% for the entire event. Patients with SHD had significantly higher percent crSO
2
measurements

≥ 30%, 40%, 50%, and 60% for the entire event (Table). Multivariable analysis controlling for age (aOR 1.02 [CI 1.01,1.05] p=0.012) and cyanotic heart disease (aOR 1.03 [CI 1.01,1.05] p=0.008) showed median crS0
2
was independently associated with ROSC.

Conclusions:
Higher median crSO
2
(measured by cerebral NIRS) during pediatric IHCA was significantly associated with increased rate of ROSC and SHD. Studies evaluating intra-arrest cerebral rSO
2
may provide insight and possibly serve as a predictor of ROSC and SHD.
Abstract 307: Kids Save Hearts Project: Hands-only Cardiopulmonary Resuscitation Training For Schoolchildren
Authors: Bispo Diaz Toledo Martins Isabella , Simões Nakano Giuliana , Simões Nakano Manuela , Silva Pedro , Rossignoli Vinicius , Batista Rafael , Cardoso Thiago , Ramos Francine , Medeiros Leonardo , Zutin Tereza Lais , dos Santos Emílio , Romão Julia , Florentino Miguel , Girotto Nayla , Tahara Yuuki , Cunha Gabriel , Flato Uri , Penna Guimaraes Helio
Published: June 2023

Introduction:
As part of a global initiative, several countries already provide cardiopulmonary resuscitation (CPR) training to children in school environments. This training is not a part of the Brazilian school curriculum, but it is necessary since cardiorespiratory arrest events are frequently fatal.

Objective:
This study investigates the effectiveness of hands-only cardiopulmonary resuscitation among different age groups of schoolchildren.

Methods:
The institution's research ethics committee previously approved the study. Prior to training, both parents and participants signed a consent form. This study was conducted in three (public and private) schools using a quasi-experimental intervention with two age groups: 7 to 11 (group I) and 12 to 17 (group II). The 90-minute training module consisted of short practice videos while watching a song dedicated to "hands-only CPR." Students were then individually evaluated for their skills and knowledge using Skill Reporter Software Laerdal Medical during one minute of chest compressions on a manikin and a dedicated game.

Results:
The total of 102 schoolchildren (54 females and 48 males) (table1) were trained and evaluated for demographic variables (rate, depth, recoil) and chest compression quality according to international guidelines 2020. There were differences in the physical characteristics of participants (p<0.05) and significant statistical difference related to depth in CPR (median 66 mm; p: 0,01) in group II.

Conclusion:
It was concluded that schoolchildren performing hands-only cardiopulmonary resuscitation were adequate, and those future efforts are required to implement and expand training in low-income regions of Brazil.
Abstract 311: Performance of Video-assisted Cardiac Arrest Recognition Protocol for Emergency Medical Dispatch in Out-of-hospital Cardiac Arrest
Authors: Kim Tae Han , Song Kyoung J , Hong Kijeong , LEE Stephen Gyung Won G , choi seul ki , Kim Ki Hong
Published: June 2023

Introduction:
Cardiac arrest recognition in emergency medical dispatch (EMD) is an important process for initiation of telephone CPR that could lead to bystander CPR before emergency medical service (EMS) arrival. Video-assisted protocol was developed and implemented for better recognition of cardiac arrest suspected calls that recognition was uncertain under conventional audio-call dispatch. We tested the performance of video-assisted protocol after pilot implementation in a dispatch center.

Methods:
All emergency medical dispatch calls received by Seoul emergency dispatch center that used video-assisted recognition protocol from Jun. 2020 to Dec. 2020 were enrolled. The primary outcome was the presence of cardiac arrest at EMS arrival evaluated by EMS providers arrived at the scene. The predictive performance measure of video-assisted protocol was calculated including sensitivity and specificity with 95% confidence interval (CI).

Result:
During the study period, video-assisted protocol was used in 115 emergency calls that dispatchers were uncertain during initial audio-call. In 15 cases the dispatcher additionally recognized the case as cardiac arrest under video-assistance. Of recognized cases, 14 (93.3%) cases were cardiac arrest when EMS arrived at scene. The sensitivity (95% CI) and the specificity (95% CI) of video-assistance protocol were 63.6% (40.7 - 82.8) and 98.9% (94.2 - 100) respectively.

Conclusion:
Use of video-assisted protocol helped recognizing additional cardiac arrest cases that could not be recognized with the audio-call in the dispatch center. Technological and operational improvement should be continuously studied for better cardiac arrest recognition using video-assisted protocol during emergency call taking.
Abstract 314: Changes In The Hounsfield Unit Proportion Of Head Computed Tomography With Time And Neurological Outcomes In Out-of-hospital Cardiac Arrest Survivors
Authors: In Yong Nam
Published: June 2023

Changes in the Hounsfield Unit proportion of head computed tomography with time and neurological outcomes in out-of-hospital cardiac arrest survivors

Aim:
We compared changes in Hounsfield Unit proportion (HUp) with neurological outcomes using head computed tomography (HCT) obtained before and after targeted temperature management of out-of-hospital cardiac arrest (OHCA) survivors.

Methods:
This retrospective observational study included adult comatose OHCA survivors who underwent HCT scans within 6 h (first HCT) and 72-96 h (second HCT) after the return of spontaneous circulation (ROSC). Automated quantitative analysis using non-enhanced HCT images was applied to identify the difference in HU value distribution across the intracranial area between neurological outcomes. Each pixel in an HCT image has a certain HU level, λ, which is between 1 and 79 in this study. The proportion (%) of λ in a CT image is 0 to 100, with the sum of every λp as 100, as per the definition of λp. The primary outcome was the 6-month poor (CPC 3-5) outcome.

Results:
Of the 41 included patients (30 males; 73%), 14 (34%) had poor outcomes. In the first HCT, only HU = 29-30 showed a difference according to the neurological outcome; however, in the second HCT, HU = 1-12, 22-33, 39-50 showed a difference (
P
< 0.05) (Fig. 1). Among them, the greatest difference between the good and poor neurological outcome groups was the proportion of pixels with HU = 22-33, and the average values were 36.0 ± 6.0 and 43.6 ± 8.1, respectively (
P
< 0.01). In addition, receiver operating characteristic analysis showed that the of the second HCT was predictive of prognostic performance from poor neurological outcomes six months after ROSC to moderate to good (0.76; 95% confidence interval, 0.60-0.88).

Conclusions:
The proportion of in total cerebral regions in HCT scans obtained between 72-96 hours after ROSC in OHCA survivors was associated with poor neurological outcomes six months after ROSC.
Abstract 334: Cardiogenic Shock In Heart Transplant Candidates - Improved Outcome With Impella 5.5
Authors: Freundt Miriam , Devich Robert , Mahesh Balakrishnan , Eisen Howard J , Soleimani Behzad , Dowling Robert D
Published: June 2023

Background:
Heart transplant (HTX) candidates often develop cardiogenic shock (CS) and require mechanical circulatory support (MCS). UNOS criteria prioritize temporary MCS over durable left ventricular assist devices (LVADs). Extracorporeal membrane oxygenation (ECMO) or intra-aortic balloon pump are associated with poor outcome. In early 2020, we transitioned to using axillary Impella 5.5 in CS patients with both isolated LV or biventricular failure as bridge to HTX. This reports our two-year experience.

Methods:
We performed a retrospective single center chart review. 19 patients treated with Impella 5.5 as bridge to HTX were identified. UNOS criteria were used to classify CS. If inotropes and diuresis failed to resolve CS, Impella 5.5 was placed via a 10 mm graft sewn to the axillary artery. Key endpoints were survival to transplant without disabling stroke, 30-day and 1-year post-HTX survival.

Results:
Mean age 55 yrs, 89% male, mean Impella support 19 days (2 - 71, total 369). 58% biventricular failure with at least moderate right ventricular dysfunction (RVD). RVD was managed medically, no RV assist device or ECMO was needed. Transient elevation (>40 mg/dl) of free plasma hemoglobin occurred in 42% but resolved with device repositioning and/or fluids. No renal replacement therapy was required. No serious infectious, vascular or bleeding complication occurred. There was no device malfunction, one pump was replaced due to an exposed wire after 22 days of support. 100% of patients were able to ambulate prior to HTX. Overall survival was 100%. 89% patients were successfully bridged to HTX without major morbidity. Two cases received durable LVAD. One developed non-disabling ischemic stroke on day 16 of Impella support. One elected LVAD as destination therapy after 71 days of support. Stroke free survival during Impella support was 95%. There were no disabling strokes. Post-transplant 30-day survival was 100% (n=17). 1-year post-HTX survival data was 100% (n=10).

Conclusion:
Impella 5.5 successfully restores hemodynamics in CS in HTX eligible patients with both isolated LV and biventricular failure. RVD in this situation can be managed medically. With this strategy, patients are able to ambulate prior to HTX and survival after HTX exceeds national average.
Abstract 9265: Real-World Disparities in Remote Follow-Up of Cardiac Implantable Electronic Devices and Impact of the Covid-19 Pandemic: A Single Center Experience
Authors: Lehmann H Immo , Sharma Krishan , Bhatia Roma , Li Guoping , Lang Joshua , Singh Jagmeet , Mela Theofanie
Published: June 2023

Introduction:
Remote monitoring (RM) of cardiac implantable electronic devices (CIEDs) has been shown to improve cardiovascular morbidity and mortality. To date, no studies have investigated disparities in utilization and delivery of RM. This study was performed to investigate if racial and socioeconomic disparities are present in CIED RM.

Methods:
Retrospective observational cohort study at a single tertiary care center in the United States. Patients who received a newly implanted CIED or device upgrade between 01/17 to 12/20 were included. Patients were classified as RM positive when they underwent at least ≥2 remote interrogations per year during follow-up.

Results:
Of all eligible patients, 2520 patients were included and 35% were female. The mean follow-up was 25 months. Mean age was 71±14 years. Pacemakers constituted 66% of implanted devices, while 26% were ICDs, and 8% CRT-Ds. Most patients (83%) were White non-Hispanic (WNH) patients. During follow-up, 66% of patients were classified as RM positive. In an adjusted regression model, these patients were younger (p=0.025) and more frequently had an ICD (HR=1.68; p<0.001). RM positive patients more frequently had an advanced college degree (HR=1.27; p=0.026) and used the online patient portal (HR=2.22; p<0.001). They lived in counties with higher median income (p=0.040) and were more frequently WNH patients (p=0.002). In a Cox regression analysis, RM status was associated with death (HR=0.487, p<0.001, Figure). During the years of the COVID-19 pandemic, RM positive patients increased and influence of income and race decreased.

Conclusions:
Despite being offered to all patients at implantation, significant disparities were present in CIED RM in this cohort. Disparities were partly reversed during COVID-19. Further studies are needed to examine health center and patient specific factors to overcome these barriers, and to facilitate equal opportunities to participate in RM.
Abstract 9328: Sirt5 Deficiency Promotes Metabolic Reprogramming to Aggravate Cardiac Fibrosis
Authors: Wu Maoxiong , Zhang Haifeng , Yuan Woliang , Tan Jing , Huang Zhaoqi , Chen Zhiteng , Guo Qi , Su Zizhuo , Yang Ying , Gao Qingyuan , Qiu Qiong , Liu Zhaoyu , Wang Jingfeng , Chen Yangxin
Published: June 2023

Introduction:
Metabolic remodeling is critically involved in the pathogenesis of cardiac fibrosis. Glycolytic switch provides rapid energy production and biosynthetic intermediates to support proliferation and collagen synthesis of fibroblast. Sirtuin 5 (Sirt5) is a protein lysine de-succinylase that impacts diverse metabolic pathways.

Objective:
This study aimed to determine the function and mechanism of Sirt5 in cardiac fibroblast activation and cardiac fibrosis.

Methods and Results:
SIRT5 expression was examined in human and mouse myocardia, and was found to be downregulated in fibrotic myocardial tissues compared to non-fibrotic tissues. In a mouse model of myocardial infarction, Sirt5-knockout (KO) mice showed more severe cardiac fibrosis compared with wild-type mice. The aggravating cardiac fibrosis of Sirt5-KO mice were also found after transverse aortic constriction or angiotensin II plus phenylephrine-infusion. Proliferation and collagen synthesis of cardiac fibroblasts (CFBs) were both significantly enhanced by SIRT5 deficiency after AngII/PE-infusion
in vivo
and transform growth factor (TGF)-β1-treatment
in vitro
, but were attenuated by overexpression of Sirt5
in vitro
. Moreover, Sirt5 deficiency enhanced a metabolic switch from oxidative phosphorylation to glycolysis in the isolated CFBs, and inhibition of glycolysis diminished the effect of Sirt5 deficiency on CFBs activation. Mechanistically, lysine succinylome analysis identified phosphoenolpyruvate carboxykinase 2 (Pck2), a rate-limiting enzyme in glycolysis pathway, as the protein mostly succinylated after Sirt5 deficiency. Activity of Pck2 was significantly inhibited by Sirt5 deficiency-mediated hypersuccinylation both
in vivo
and
in vitro
. K489R mutation of Pck2 diminished its succinylation and the reduction of its enzymatic activity mediated by Sirt5 deficiency, which also blunted the effect of Sirt5 deficiency on CFBs activation.

Conclusions:
Sirt5 deficiency enhances a metabolic reprogramming from oxidative phosphorylation to glycolysis in CFBs by succinylating Pck2, which promotes CFBs activation and aggravates cardiac fibrosis.
Abstract 9382: Reperfusion Delays and Outcomes Among ST-Segment-Elevation Myocardial Infarction Patients With and Without Cardiogenic Shock
Authors: Kochan Andrew F , Lee Terry , Moghaddam Nima , Milley Grace , Singer Joel , CAIRNS John A , Wong Graham C , Fordyce Christopher
Published: June 2023

Introduction:
Mortality remains high among STEMI patients with cardiogenic shock (CS), and rapid reperfusion has been shown to improve outcomes. However, the comparative benefits of shorter reperfusion times among STEMI patients with and without CS is unclear.

Hypothesis:
STEMI patients presenting with CS would have significantly greater increases in mortality and MACE as FMC-to-device time increased compared to non-CS patients. We hoped to identify a FMC-to-device time threshold below which outcomes were optimized for CS and non-CS patients.

Methods:
We performed a retrospective analysis using prospective data from the Vancouver Coastal Health Authority STEMI registry. We included all patients with STEMI who received PCI between January 1, 2010, and December 31, 2020. Patients were stratified based the presence of CS at the time of admission and assessed for the primary outcome of in-hospital mortality and the secondary outcome of an in-hospital major adverse cardiovascular event (MACE), defined as a composite of the first occurrence of mortality, cardiac arrest, heart failure, ICH/CVA/Stroke or reinfarction. Logistic regression was used to estimate the relationships between FMC-to-device time and the primary and secondary outcomes in the CS and non-CS groups.

Results:
2929 consecutive STEMI patients were included, of whom 9.4% (n= 275) had CS. Median FMC-to-device time was 113.5 (IQR 93.0-145.0) minutes for CS patients and 103.0 (IQR 85.0- 130.0) minutes for non-CS patients. CS patients were more likely to have FMC-to-device times above guideline recommendations (76.6% vs. 54.1%, p <0.001) compared to non-CS patients. Between 60 and 90 minutes, for each 10-minute increase in FMC-to-device time, mortality for STEMI patients with CS increased by 5-8%, while for non-CS patients it increased by less than 0.5%. Compared to non-CS patients, those with CS had higher incidences of mortality (41.1% vs. 1.9%, p <0.001) and MACE (81.1% vs. 19.4%, p <0.001).

Conclusions:
Among STEMI patients undergoing primary PCI, reperfusion delays among CS patients are associated with significantly worse outcomes compared to non-CS patients. Strategies to reduce FMC-to-device times for STEMI patients specifically presenting with CS are needed.
Abstract 9395: Natural History of Myocardial Injury Following Covid-19 Vaccine Associated Myocarditis
Authors: Mustafa Alhussein Muhammad , Rabbani Mohamad , Sarak Bradley , Dykstra Steven , Labib Dina , Flewitt Jacqueline , Lydell Carmen , Howarth Andrew G , Filipchuk Neil G , Kealey Angela , Colbert Jillian , Guron Nita , Kolman Louis , Merchant Naeem , Bandali Murad , Bristow Mike , White James A
Published: June 2023

Introduction:
Acute myocarditis is a rare complication of mRNA-based COVID-19 vaccination. The natural history and clinical sequalae of this complication are of critical importance to estimate the impact on population health.

Objective:
To study the impact of COVID-19 vaccine associated myocarditis on convalescent myocardial health, symptoms, and clinical outcomes.

Methods:
This study was performed at two tertiary care hospitals. Baseline and convalescent (≥3 month) CMR imaging was performed for 20 consecutive patients meeting Updated Lake Louise Criteria for acute myocarditis within 10 days of mRNA-based vaccination and with no evidence

of active viral infection. Global and segmental CMR-based markers of myocardial injury were studied at baseline and convalescence, inclusive of chamber volumetry, LV ejection fraction (LVEF), LV mass, T1 and T2 mapping, late gadolinium enhancement (LGE) imaging, and extracellular volume (ECV) fraction. Major clinical outcomes were captured.

Results:
The median age was 23.1 years (range 18-39 years) with 17 (85%) being male. Convalescent CMR evaluations were performed at a median (IQR) of 3.7 (3.3-6.2) months. Five patients (25%) had a baseline LVEF <50%. All patients showed abnormal LGE inclusive of a sub-epicardial pattern with a mean LGE burden of 8.6+/-5.3% LV mass using a >5SD of reference threshold. At follow-up, a mean 3% absolute improvement in LVEF was observed, accompanied by a 7% reduction in LVEDV and 5% reduction in LV mass (all p<0.015). Global LGE volume reduced by 66% (p<0.001). Absolute reductions in global T2, native T1, and ECV of 2.1msec, 58msec, and 2.9%, respectively were documented (all p≤0.001). All patients with LVEF <50% at baseline recovered above this threshold. However, 18 (90%) patients showed persistence of LGE at follow-up with 15% having a burden >5% of the LV mass. No patient experienced major clinical outcomes.

Conclusion:
COVID-19 mRNA vaccine associated myocarditis shows rapid improvement in CMR-based markers of tissue edema, contractile function, and LGE, and was not associated with adverse events at intermediate range follow-up. However, convalescent fibrosis was commonly observed, justifying ongoing need for clinical surveillance in this population.