bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 255: Association Of Hospital Market Area Dominance With Out-of-hospital Cardiac Arrest Survival To Admission
Authors: Buckler David G , Abbott Ethan , Carr Brendan G , Wiebe Douglas , Zebrowski Alexis
Published: June 2023

Introduction:
Access to care has been measured by geographic distance, transport time or provider density. For emergency care sensitive conditions, like out-of-hospital cardiac arrest (OHCA), market area coverage may be associated with short-term outcomes due to the need for access to definitive care. Our objective was to evaluate the association of market area dominance with survival to hospital admission.

Methods:
ED-treated OHCA were identified in age-eligible Medicare fee-for service claims using ICD 9/10 codes and ED charges. Hospital market shares were defined as the cumulative proportion of all OHCA claims treated at the hospital of interest within a group of ZIP code tabulation areas (ZCTAs) centered around the hospital. Market share was calculated using sequential addition of ZCTAs. Hospital Market Areas (HMAs) included all ZCTAs where the cumulative market share exceeded a threshold (<50% 50-74% 75-89% ≥90%). Survival to admission was determined using in-patient claims and vital status data. The primary predictor, maximum HMA threshold, is the highest market share proportion covering that ZCTA. A ZCTA with a 90% max HMA has one hospital treating 90% of OHCA case in that ZCTA or closer. Relative risk of survival was calculated using modified Poisson regression with hospital random effect and patient characteristics (age, sex, race, comorbidity).

Results:
Of the 194,914 claims treated at 4,436 hospitals between 2013 and 2015, 45% were female, 16% Black, 77% White, and 50% from large metro areas. 28% of claims were from a ZCTA with <50% max HMA (an area where no single hospital treats the majority of OHCA). Relative risk of survival to admission decreased as the max HMA increased [RR[95%CI] 50-74%: 0.97[0.95, 0.99]; 75-89%: 0.94 [0.91, 0.98]; ≥90%: 0.90 [0.83, 0.98]. Small and non-metro areas were associated with lower survival likelihood. Interactions were not significant between max HMA and small metro areas; non-metro areas saw a greater reduction in survival likelihood for ZCTAs with max HMAs >75%.

Conclusion:
For OHCA, market dominance was associated with lower likelihood of survival to hospital admission. The likelihood of survival decreased as market dominance increased. Further study is needed to develop strategies to mitigate this disparity.
Abstract 258: Age, Sex And Survival Of Ventricular Fibrillation Out-of-Hospital Cardiac Arrest: The Influence Of Electrocardiogram Waveform Measures
Authors: Yang Betty Y , Coult Jason , Blackwood Jennifer E , Kwok Heemun , Rajah Anjali , Goldenberg Ilan , Sootedehnia Nona , Kudenchuk Peter J , Rea Thomas
Published: June 2023

Background:
Studies of sex-based outcome in out-of-hospital cardiac arrest (OHCA) have produced mixed results that may depend on age. Menopause produces a range of effects that may influence resuscitation. We used quantitative measures of the presenting OHCA ventricular fibrillation (VF) waveform - a surrogate of the myocardium’s acute physiology - to assess whether outcome differences according to sex and age group may be mediated via a biologic mechanism.

Methods:
We conducted a retrospective cohort study of adults with non-traumatic VF-OHCA in a metropolitan Emergency Medical Services system between 2008-2020. We used multivariable logistic regression to assess the association of outcome (survival to hospital discharge, favorable neurological outcome (Cerebral Performance Category (CPC) 1 or 2), with sex and age group (<55,
>
55 yrs). We then determined the proportion of the outcome difference mediated by the waveform measure by incorporating previously described quantitative VF waveform measures - an estimated probability of survival (P
Survival
) and amplitude spectrum area (AMSA - into the model individually.

Results:
Of 1526 VF-OHCA patients, average age was 62 years, and 29% were female. Overall, younger women were more likely to survive than younger men (survival 67% vs 54%, p=0.02 with CPC 1-2 61% vs 51%, p=0.07), while older women and older men had similar worse outcomes. After adjusting for Utstein characteristics, women <55 compared to men <55 was associated with greater odds of survival to hospital discharge (OR 1.93, 95% CI 1.23-3.09, p=0.005) and CPC 1-2 survival (OR 1.72, 95% CI 1.10-2.71, p=0.02), whereas no associated sex-based differences in these outcomes were observed between the older groups. Each waveform measure mediated some of the beneficial association between sex and age group with survival: 47% for P
Survival
and 25% AMSA.

Conclusions:
Women <55 years were more likely to survive to hospital discharge and with favorable neurological status compared to men <55 years, a sex-associated outcome difference not observed in the older age group. The biologic mechanism represented by VF waveform measures mediated some (47% at most), though not all, of the outcome differences.
Abstract 261: Association Of Neighborhood Social Determinants Of Health With Adverse Out-of-hospital Cardiac Arrest (OHCA) Outcomes Among Medicare Beneficiaries
Authors: Ngai Ka Ming G , Petrozzo Kevin , Buckler David , Zebrowski Alexis M , Carr Brendan G
Published: June 2023

Introduction:
Out-of-hospital cardiac arrest (OHCA) is a leading cause of death with prior studies demonstrated worse OHCA outcomes in neighborhoods with higher proportion of Blacks and lower socioeconomic status. The association between OHCA outcomes and other social determinants of health (SDOHs) like limited English proficiency (LEP) and education is not well studied.

Hypothesis:
We hypothesized patients living in neighborhoods with high proportion of LEP had worse OHCA outcomes. We chose survival to hospital admission as the primary outcome due to its proximity to reflect a neighborhood’s characteristics.

Methods:
We performed a two-level hierarchical logistic-regression model. Patient data were Medicare fee-for-service claims between January 1, 2013, and December 31, 2015 (level 1). Neighborhood characteristics for the area in which each OHCA occurred were derived from the 2014 American Community Survey at the ZCTA level (level 2). We identified six neighborhood SDOH predictors of interest including LEP, median household income, racial and ethnic-group composition, percent unemployment, less than high school education, and population density.

Results:
Among the 194,231 OHCA events identified, 60,760 (31.3%) survived to hospital admission. Contrary to our hypothesis, Patient who had a cardiac arrest in the highest proportion of LEP neighborhoods were more likely to survive to hospital admission as compared to those living in predominantly English-speaking neighborhoods (OR 1.16; 95% CI, 1.10 to 1.23). Household income, racial composition, and unemployment had no effect on the likelihood of survival to hospital admission in OHCA while education and population density appeared to be protective
(Table)
.

Conclusions:
In a large cohort study, we found that patients who had an out of hospital cardiac arrest were more likely to survive to hospital admission in higher LEP, higher education, and higher population density neighborhoods.
Abstract 266: Impact Of Bystander-patient Relationship On Neurological Outcome In Witnessed Elderly Patients With Out-of-hospital Cardiac Arrest According To Age: A Nationwide Population-based Observational Study
Authors: Funada Akira , Goto Yoshikazu , Takamura Masayuki
Published: June 2023

Introduction:
Elderly patients with out-of-hospital cardiac arrest (OHCA) witnessed by a family member were associated with worse neurological outcome than those witnessed by a non-family bystander.

Hypothesis:
Impact of bystander-patient relationship (family member or non-family bystander) on neurological outcome in witnessed elderly OHCA patients could differ based on age.

Methods:
We evaluated 13,773 bystander-witnessed elderly OHCA patients (age ≥ 65 years) of cardiac origin who achieved prehospital return of spontaneous circulation (ROSC). Data were obtained from the prospectively recorded All-Japan Utstein-style Registry between 2011 and 2016. The primary outcome was 1-month neurologically intact survival, defined as a cerebral performance category (CPC) score of 1 or 2. Patients were divided into three groups by age (65-74, 75-89, and ≥ 90 years).

Results:
The rates of 1-month CPC 1-2 and the frequencies of bystander-initiated cardiopulmonary resuscitation (BCPR) were significantly higher in patients witnessed by a non-family bystander [27.4% (1,360/4,971) and 68.5% (3,407/4,971)] than in those witnessed by a family member [19.7% (1,736/8,802) and 44.8% (3,942/8,802)] (p < 0.001, respectively). The rates of 1-month CPC 1-2 in patients aged 65-74, 75-89, and ≥ 90 years decreased with advancing age, 36.2% (1,733/4,788), 16.9% (1,264/7,469), and 6.5% (99/1,516), respectively (p for trend < 0.001). The rates of 1-month CPC 1-2 were significantly higher in patients witnessed by a non-family bystander than in those witnessed by a family member in those aged 65-74 years (45.0% and 30.9%) and 75-89 years (20.2% and 15.3%) (p < 0.001, respectively), but not in those aged ≥ 90 years (6.4% and 6.7%, p = 0.83). In multivariate logistic regression analysis adjusted for sex, initial rhythm, and time from call receipt to ROSC, witness by a non-family bystander and BCPR were significantly associated with 1-month CPC 1-2 for patients aged 65-74 years (adjusted odds ratio: 1.37 and 1.44, respectively; 95% confidence interval: 1.19-1.58 and 1.26-1.66, respectively), but not in those aged 75-89 and ≥ 90 years.

Conclusions:
Impact of bystander-patient relationship on neurological outcome in witnessed elderly OHCA patients varied with age.
Abstract 272: Withholding/withdrawal Of Life-sustaining Therapy Decision For Out-of-hospital Cardiac Arrest Patients With Extracorporeal Cardiopulmonary Resuscitation Is Commonly Influenced By Perceived Unfavorable Neurological Prognosis At Early Admission
Authors: Naito Hiromichi , Sakuraya Masaaki , Hongo Takashi , Yumoto Tetsuya , Nakao Atsunori
Published: June 2023

Introduction:
Extracorporeal cardiopulmonary resuscitation (ECPR) in patients with refractory cardiac arrest is rapidly becoming a common strategy worldwide. Despite its benefits, ECPR is still associated with significant morbidity, including a high prevalence of brain injury/ischemia. ECPR raises a variety of ethical concerns when discontinuing treatment, however, there is little information about the withholding/withdrawal of life-sustaining therapy (WLST) decision for out-of-hospital cardiac arrest (OHCA) patients after ECPR.

Hypothesis:
We tested whether early WLST is obtained in OHCA patients with ECPR, and examined the differences in patient characteristics between ECPR/OHCA patients with or without WLST.

Methods:
We conducted a post-hoc analysis of data from the SAVE-J II study (a retrospective, multicenter study of ECPR in Japan from 2013 to 2018). Inclusion criteria: Patients who underwent ECPR for OHCA with internal causes. Exclusion criteria: death in the emergency department (without admission), diagnosis of brain hemorrhage/acute aortic dissection as cause of arrest. The dates and reasons for the decisions were recorded. Further, differences between ECPR/OHCA patients with or without WLST were compared using univariable analysis.

Results:
We included 1651 patients in the analysis; WLST was decided in 506 (31%) of patients at a median of two days. WLST was decided within three days in 291 patients (18%). Reasons for WLST decision were perceived unfavorable neurological prognosis (285/477 [59.7%]), perceived unfavorable cardiac/pulmonary prognosis (99/477 [20.7%]), inability to maintain extracorporeal cardiopulmonary support (71/477 [14.8%]), complications (12/477 [2.5%]), and others (10/477 [2%]). Older age (WLST vs. non-WLST, median [IQR]: 63 [51-71] vs. 61 [49-68], p=0.001) and daily hemodialysis before the collapse (7.7% vs. 4.7%, p=0.015) were factors in the WLST decision. Patients with WLST had higher 1 month mortality (505/506 [99.8%] vs. 889/1145 [77.6%], p<0.001).

Conclusion:
About one-third of ECPR/OHCA patients had WLST decided at a median of two days, mainly for perceived unfavorable neurological prognoses reason. Decisions and neurological assessments for ECPR/OHCA patients need further analysis.
Abstract 287: Trends In Cardiac Arrest Outcomes In Children With Cardiac Disease: An Analysis From The Aha Get With The Guidelines
®
Database
Authors: Gardner Monique M , Morgan Ryan W , Reeder Ron , Ghaffari Kimia , Ortmann Laura , Raymond Tia T , Lasa Javier J , Fowler Jessica , Dewan Maya , Nadkarni Vinay M , Berg Robert A , Sutton Robert M , Topjian Alexis A
Published: June 2023

Introduction:
Contemporary rates of survival after pediatric in-hospital cardiac arrest (IHCA) and trends in survival over the last 20 years have not been compared based on illness category. We hypothesized that (1) survival to hospital discharge for surgical-cardiac category is higher than the non-cardiac category, and (2) rates of survival after IHCA increased over time in all categories.

Methods:
The AHA Get With The Guidelines
®
-Resuscitation database was queried for index IHCA events (excluding delivery room and neonatal intensive care unit) in children <18 years of age from 2000-2021. Categories were defined as: surgical-cardiac, IHCA following cardiac surgery; medical-cardiac, IHCA in non-surgical cardiac disease; and non-cardiac, IHCA in patients without cardiac disease. The primary outcome was survival to hospital discharge. We compared eras 2000-2004, 2005-2009, 2010-2014, and 2015-2021 with mixed logistic regression models, including event year as a continuous predictor and site as a random effect.

Results:
Of 17,696 index events, IHCA by illness category were: 18% surgical-cardiac, 18% medical-cardiac, and 64% non-cardiac. Surgical-cardiac category had the highest rate of survival to discharge compared to medical-cardiac and non-cardiac categories (56.1% vs. 43.4% vs. 46.3%; p<0.001). After controlling for age, location of event, and hospital size, the odds of survival were higher for surgical-cardiac category (aOR 1.28 (1.16, 1.40)) and lower for medical-cardiac category (aOR 0.87 (0.80, 0.95)), compared to the non-cardiac category. Odds of survival increased for all illness categories across eras. Between the 2000-2004 and 2015-2021 eras, survival in surgical-cardiac subjects increased from 45.6% to 62.3% with odds of survival increasing by 24% per era, (OR 1.24 (95% CI 1.15, 1.35), and survival for medical-cardiac subjects increased from 36.6% to 47.0%, with 14% increased odds per era (OR 1.14 (1.06, 1.23)).

Conclusions:
Over the last 20 years, children with surgical-cardiac IHCA have substantially higher odds of survival to hospital discharge compared to non-cardiac IHCA categories, whereas odds of survival were worse with medical-cardiac IHCA. Survival to hospital discharge has increased in all IHCA illness categories.
Abstract 294: Is Use Of An Interactive Voice Server In An Emergency Medical Dispatch Center An Efficient And Safe Measure?
Authors: CASSUTO MARGOT , BOYET MARIN , Boutet Jeremie , DOUGE GUILLAUME , OZGULER ANNA , Baer Michel , Loeb Thomas
Published: June 2023

Introduction:
In the first wave of COVID-19 pandemic, Emergency Medical Dispatch Centers (EMDC) faced an influx of calls. During this time, with the scope of handling emergency calls more quickly, it was decided to use an Interactive Voice Server (IVS). The objective of this study was to identify whether the implementation of an IVS is efficient and safe.

Methods:
From 20/03/19 until 20/04/26, an IVS was activated between 8 AM and midnight. IVS offered the caller to choose either 1- press the 'zero' key for Coronavirus Syndrome with no respiratory difficulties; or 2- stay on line for any other reason. If the caller typed "zero", the call was directed to a "crisis dispatcher" specially trained to handle COVID cases. If he stayed on line, his call was placed in the same queueing list as all emergency calls and handled by a “conventional dispatcher”. All medical dispatch files picked up during IVS activation period were included and classified in 2 groups: “IVS Yes” if caller pressed ‘zero’ and “IVS No” if not. Patient’s age, gender and profile of the caller (patient or third party) were collected. The level of severity of the patients was assessed upon the dispatcher’ decision ranging from sending an Advanced Life Support ambulance (ALS), a Basic Life Support ambulance (BLS) or no transport. Data were compared between the 2 groups with Chi-square tests.

Results:
2846 callers were in the group “IVS Yes” and 12111 in “IVS No”. Main results are in table 1.

Conclusion:
IVS allowed almost 15% of calls to be directed to a specialized provider where they waited to be processed by staff trained within a few days to deal exclusively with COVID cases. This has led to decrease the number of calls handled by the conventional dispatch and allowed more time to respond to severe emergency calls. Moreover, because only 0.07% “IVS Yes” needed an ALS ambulance, we can assume that the use of IVS is safe. IVS is therefore an effective tool, which allows safe triage of less serious patients and frees up time to answer to severe calls.
Abstract 309: Exploring Competencies For The Family Facilitator During Resuscitation
Authors: Tennyson Carolina
Published: June 2023

Title:
Exploring Competencies for the Family Facilitator in Resuscitation

Authors:
Carolina D. Tennyson, John P. Oliver, Karen R. Jooste

Character Count (1,474 of 1,700)

Introduction:
During instances of family presence during resuscitation (FPDR), the family facilitator (FF) acts as a partner, advocate, and support person for the family as well as a liason between the family and care team. This role is widely recommended when implementing FPDR, however standard competencies for the FF have not been clearly described. To develop competency-based education or a certification for the role, FF skills and knowledge need to be detailed by those who currently work with the resuscitation team in this capacity.

Hypothesis:
The skills of the FF include timely assessment, communication with diverse populations (verbal and nonverbal), psychosocial and emotional support, and crisis management skills.

Methods:
Inpatient Chaplains who routinely respond to Code Blue events gathered in a focus group to review their current role responsibilities while caring for family members during resuscitation events. Qualitative data were collected and categorized by theme.

Results:
Fifteen Chaplains with FF role experience attended the focus group. Identified skills fell into the following 6 categories; Responding rapidly, Recognition of space, sterility, and safety elements in the resuscitation arena; Performing an ongoing assessment of family’s response to crisis; The ability to provide active listening and partnering; Facilitating communication between family and the Code Blue team leader; and interprofessional communication with the Code Blue team.

Conclusions:
Competency-based education and training for the FF role requires an understanding of the job demands and responsibilities. The described skills will be used to shape competencies and educational objectives for future FF training.
Abstract 310: Disparities Between Reported And Actual First Pass Discovered After Video Review Of Prehospital Intubations
Authors: BURNS TIMOTHY A , Wang Henry , Stone Roger , Kaufman Ben
Published: June 2023

Purpose:
Often emphasized as a best practice in prehospital airway management, first-pass intubation success (FPS) depends upon paramedic self-reports. We sought to determine the accuracy of paramedic reports of FPS in prehospital airway management.

Methods:
We analyzed adult (age >=18 years) prehospital airway management data from a ground EMS agency, including cases from 5/1/2020 to 2/28/2022. Paramedics performed all adult prehospital endotracheal intubations (ETI) using standard video laryngoscopy (Airtraq, Mountain View CA) with a hyperangulated blade. Paramedics did not use neuromuscular blocking agents for ETI. Real time video images were recorded for all cases. We excluded cases where the video was missing, data was not captured, or the video was of insufficient quality. Each video was reviewed by a single independent rater using the same objective definition of FPS as the paramedic. The primary outcome was FPS, defined as correct intratracheal placement on the first video laryngoscopy. We evaluated agreement between paramedic and reviewer-reported FPS using Cohen’s Kappa statistic.

Results:
There were a total of 514 ETI cases, including cardiac arrest, trauma, and non-arrest medical. Paramedic and reviewer reported FPS agreed in 429/514 (83.5%) and disagreed in 85 (16.5%). Of the discordant cases, the paramedic reported FPS but the reviewer disagreed in 78 (92%). Interrater agreement was strong; kappa 0.659 (95%CI 0.595 - 0.722). FPS discordance was not associated with patient age, sex, cardiac arrest status.

Conclusions:
Despite the computed Kappa statistic showing strong interrater reliability, the objective nature of the rating leaves very little room for discordance. The expected result would have been near compete agreement, however 15% of cases resulted in disagreement. Additionally, when there was disagreement, it overwhelmingly favored the clinician reporting FPS when the reviewer disagreed. Paramedics incorrectly reported FPS in 1 of 6 ETI. Independent review is essential in the assessment of prehospital ETI performance. Further study is needed to determine the reasons for the discordance that may include confusion about the FPS definition or incentivization (real or perceived) of reporting outcomes in a particular way.
Abstract 315: Optimal Early Magnetic Resonance Image Scanning Time For Predicting Neurological Outcomes In Out-of-hospital Cardiac Arrest Survivors
Authors: Min Jin Hong , Park Jung Soo , You Yeon Ho , In Yong Nam , Kang Changshin
Published: June 2023

Introduction:
Several studies have shown that, in out-of-hospital cardiac arrest survivors (OHCAs), high signal intensity (HSI) on ultra-early diffusion-weighted magnetic resonance imaging (DW-MRI) can progress to extensive HSI within 72 h, leading to poor neurological outcomes. Nonetheless, the time of HSI appearance and its relationship with hypoxia severity is unknown. This study investigated the optimal time to detect HSI and its relationship with hypoxia severity in ultra-early DW-MRI.

Hypothesis:
The probability of HSI appearance increases with time and hypoxia severity.

Methods:
This retrospective, multicenter, observational study was conducted from July 2013 to February 2022 and evaluated comatose adult OHCAs who underwent DW-MRI scans within 12 h of return of spontaneous circulation (ROSC). Patients were divided into three groups based on the time from ROSC to MRI: Grade 1 (<2 h), grade 2 (2-4 h), and grade 3 (>4 h). The severity of hypoxia was based on a low flow time of 20 min. The prognostic performance of DW-MRI at each grade was analyzed using receiver operating characteristic (ROC) analysis. The prognostic performance according to low flow time (<20 min and ≥20 min) at each grade was also evaluated. The primary endpoint was a poor neurological outcome (cerebral performance category scores 3-5) at 3 months after cardiac arrest.

Results:
A total of 158 patients were enrolled, 76 of whom had HSI. The patients classified as grade 3 had the highest area under the ROC curve (AUROC) (0.94). Among Grade 1 patients, AUROC was 0.50 and 0.85 in the group with a low flow time of <20 min and ≥20 min, respectively. In the low flow time ≥20 min group, AUROCs were 0.85, 0.92, and 0.98 for each grade, respectively (Table 1).

Conclusion:
The probability of HSI suggestive of poor neurological outcomes increases in cases where the time from ROSC to DW-MRI scan increases. However, if hypoxia is severe, the probability of HSI appearing is high even if the time from ROSC to DW-MRI is short.
Abstract 317: Brain MRI And Spectroscopy Biomarkers Predict Outcome After Pediatric Cardiac Arrest In POCCA
Authors: Fink Ericka L , Kochanek Patrick M , Bluml Stefan , Wisnowski Jessica , Narayanan Srikala , subramanian subramanian , Beers Sue , Berger Rachel , Bayir Hulya , Wang Chunyan , Pineda Jose , Topjian Alexis A , maddux aline , Willyerd Frederick , Hunt Elizabeth A , Chung Melissa G , Newth Christopher , Smith Lincoln , Doughty Lesley , Diddle J. Wesley , Piantino Juan , Walson Karen H , Balakrishnan Binod , friess stuart , Siems Ashley , Press Craig , Patregnani Jason , Meyer Michael T , Haller Tamara , Treble-Barna Amery , Clark Robert , Fabio Anthony , Panigrahy Ashok ,   POCCA Investigators
Published: June 2023

Conventional (T2) and diffusion-weighted imaging (DWI) on brain magnetic resonance imaging (MRI) and lactate and N-acetyl-aspartate (NAA) on MR spectroscopy (MRS) can characterize brain hypoxic-ischemic injury. We hypothesized these neuroimaging biomarkers would be associated with 1 year outcome after pediatric cardiac arrest in a multicenter, observational study. Fourteen US centers enrolled children aged < 18 years with pediatric intensive care unit admission post-arrest if pre- arrest Pediatric Cerebral Performance Category score was 1-3. Brain MRI/MRS performed within 2 weeks post-arrest were analyzed independently by 2 pediatric neuroradiologists blinded to outcome. MRI lesions on T2 and DWI were scored by region and severity (0=none, 1=mild, 2=moderate, 3=severe). Total MRI score was a sum of T2 and DWI lesions in gray and white matter (max 34). Lactate and NAA were measured in the basal ganglia, thalamus, and occipital-parietal white/gray matter and quantified by LCModel. Multivariate regression was performed to determine the association with unfavorable outcome (Vineland Adaptive Behavioral Scale < 70 or dead at 1 year). Of 164 children, 66 and 32 had evaluable MRI and MRS data and 23 (35%) and 12 (38%) had unfavorable outcome, respectively. Children with unfavorable outcome had more unwitnessed and out-of-hospital events. DWI lesions in all 4 lobes predicted unfavorable outcome, whereas T2 temporal gray and parietal white matter lesions predicted unfavorable outcome, p<0.05. T2/DWI lesions in the basal ganglia, thalamus, and centrum semi-ovale predicted unfavorable outcome, p<0.05. Cerebellar/ brain stem white matter lesions predicted unfavorable outcome, p<.05. Total MRI scores were markedly higher in the unfavorable group (median [interquartile range]) (22 [7, 32] vs. 1 [0,8], p<0.001). Increased lactate and decreased NAA predicted unfavorable outcome in all 4 regions of interest, p<0.05. In a multivariate logistic regression, MRI total score (odds ratio 1.12 [95% confidence interval 1.05, 1.20]) and witnessed event status (0.07 [0.01, 0.34]) predicted outcome. Brain MRI and MRS biomarkers are useful to identify children with unfavorable outcome within 2 weeks post-cardiac arrest.
Abstract 318: Improvement In Cerebral Blood Flow Assessed By A Laser Speckle Imaging After Extracorporeal Cardiopulmonary Resuscitation In Rats
Authors: Endo Yusuke , Becker Lance B , Takegawa Ryosuke , Yin Tai , Hayashida Kei
Published: June 2023

Introduction:
The effect of extracorporeal cardiopulmonary resuscitation (ECPR) on recovery of cerebral blood flow (CBF) after achieving a return of spontaneous circulation (ROSC) has been undetermined. The objective of this study was to determine the impact of ECPR on the changes of CBF post-ROSC in a rat model of prolonged cardiac arrest (CA) and ECPR.

Methods and Results:
Adult Sprague-Dawley male rats (400- 500g) were subjected to 20-min of asphyxia CA whereupon animals were mechanically ventilated and resuscitated by conventional manual chest compression (CCPR, n = 6) or ECPR using venous-arterial cardiopulmonary bypass (ECPR, n = 5). Epinephrine was (20 μg/kg) intravenously injected once during CCPR but not ECPR. In the ECPR group, cardiopulmonary bypass was weaned 30 min after ROSC. ROSC was defined as achieving a mean arterial pressure > 60 mmHg. Serial changes in CBF were measured at baseline and 2 h after ROSC using the laser speckle imaging system. There was no difference in time to CA and time to ROSC as well as hemodynamics for 2 h after ROSC between the two groups. Representative CBF images at 0, 10, 60, and 120 min after ROSC are shown in
Fig. 1A.
As expected, CCPR resulted in a hyperemic phase at 10 min and then a hypoperfusion phase (~ 50 % of CBF reduction from baseline) at 60 min or later after ROSC. In the ECPR group, CBF maintained at baseline level even at 60 and 120 min after ROSC. Further, CBF levels at 60 and 120 min after ROSC were markedly higher in the ECPR group than in the CCPR group (
Fig. 1B
).

Conclusions:
Our data using laser speckle imaging suggests that ECPR is likely to improve CBF shortly after ROSC compared to CCPR.
Abstract 319: Computational Analysis Of Brain Imaging To Predict Post-arrest Brain Death
Authors: Case Nicholas P , Coppler Patrick J , Callaway Clifton W , Elmer Jonathan
Published: June 2023

Background:
Grey-white matter ratio ( GWR) can estimate severity of cerebral edema after cardiac arrest and predict progression to brain death. Current approaches to calculating GWR have variable interrater reliability. We tested if a computational technique to quantify the distribution of whole-brain x-ray attenuation at hospital admission could predict ultimate progression to brain death.

Methods:
We identified in- and out-of-hospital post-arrest patients at our single center treated between 2018-2019. We extracted demographic data from our registry and Digital Imaging and Communication in Medicine (DICOM) files for the first post-arrest CT. We analyzed the 17th slice of each DICOM, corresponding to the level of the basal ganglia. We extracted the 512x512 array of Hounsfield units (HU). We excluded HU >40 or <10 to focus on brain tissue densities. We summarized each patient’s distribution of HU and calculated the variance as a proxy for GWR. We randomly divided our data into 75% training set and 25% test set, used univariate logistic regression to predict brain death, identified a highly specific cutoff to rule out progression to brain death, and calculated test set sensitivity and specificity at this cutoff. We performed all analyses using Python.

Results:
Of 413 included patients, 163 (39%) were female, median [IQR] age was 63 [52 - 73] years, and 39 (9%) progressed to brain death. CTs were obtained a median [IQR] of 4.47 [3.03 to 6.35] hours post-arrest. HU variation predicted brain death with an area under the receiver operating characteristic curve (AUROC) of 0.81 in the training set and 0.88 in the test set. The odds ratio (OR) of progression to brain death with decreasing HU variation was 0.85 (95% confidence interval [CI], 0.80 - 0.91; P < 0.001). A cutoff of 53.9 had a sensitivity of 36% (95% CI, 30.10% to 41.33%) at 97% specificity (95% CI, 89.91% to 100%) in the training set and a sensitivity of 45% (95% CI, 34.63% to 54.73%) at 100% specificity in the test set.

Conclusion:
Preserved HU variation excludes progression to brain death in comatose post-arrest patients with high specificity.
Abstract 330: Effect Of Covid-19 Mitigation On Resource Utilization And Rates Of Acute Myocardial Infarction In Areas Of Higher And Lower Socioeconomic Vulnerability
Authors: Frantz Eric , Perzynski Adam , Wilson Lance D , Piktel Joseph
Published: June 2023

Background:
Multiple reports demonstrate decreased emergency department (ED) utilization for cardiovascular emergencies during COVID-19. It is possible this decrease had downstream effects on the later severity of cardiovascular disease, especially in patients with higher social vulnerability. The purpose of this study was to determine the effect of early COVID-19 mitigation strategies on hospital resource utilization and acute myocardial infarction (AMI) admissions by social vulnerability.

Methods:
We retrospectively analyzed patients transported by emergency medical services (EMS) with a diagnosis of chest pain and/or AMI from a large urban Midwest EMS and single hospital system from Jan 1-Dec 31, 2020. Hospital office, telehealth, ED visits for chest pain, and hospital admissions for AMI were identified using the electronic health record. The 3 phases of COVID-19 mitigation were compared (pre-mitigation-Jan 1
st
to Feb 28
th
, mitigation-March 1
st
to April 30
th
, and post-mitigation-May 1
st
-December 31
st
). The socioeconomic status theme of the Social Vulnerability Index (SVI) was determined. The primary outcome was rate of AMI per ED chest pain visit, which was compared between the highest and lowest SVI quartiles. Statistical comparisons were made using binary logistic regression and Chi-squared tests.

Results:
Overall, there was a similar increase in telehealth visits and a decrease in office visits during mitigation in both highest and lowest SVI quartiles. In the post-mitigation phase, patients with the highest social vulnerability had a 30% relative increase rate of AMI per ED chest pain visit (7.3% vs 5.5%, p=0.048) compared to patients with lower social vulnerability. This increase was not seen in the pre-mitigation (5.8% vs 6.1%) or mitigation (4.9% vs 5.4%, each p=ns) phases.

Conclusions:
After initial COVID-19 mitigation strategies were implemented patients with higher socioeconomic vulnerability presented to the ED with AMI at a higher rate than patients with a lower socioeconomic vulnerability, despite no differences in office, telehealth, or EMS transport. Understanding the complex effect of pandemic mitigation strategies on vulnerable populations can provide guidance for resource management in future crises.
Abstract 335: Hsf1 Regulates Exosome Biogenesis And Cargo Enrichment Of These Exosomes In Stem Cells Thereby Enhancing Their Potential Of Ischemic Heart Regeneration.
Authors: Guru Sameer A , Saha Progyaparamita , Gunasekaran Muthukumar , Chen Ling , Sharma Sudhish , Fu Xuebin , Krishnan Swetha , Sinha Anshuman , Kaushal Sunjay , Mishra Rachana
Published: June 2023

Introduction:
Paracrine mechanism of stem cell-based therapy holds importance. However, genes regulating the paracrine factors have not been elucidated in detail. Here in this study, we evaluated the role of HSF1 in exosome biogenesis and their composition in neonatal cardiac mesenchymal stem cells (nMSCs) in concert with ischemic heart generation.

Hypothesis:
HSF1 in nMSCs promotes production of exosomes, functional exosomal miRs cargo, and exosome acquisition by recipient cells.

Methodology:
nMSCs and adult MSCs (aMSCs) were respectively isolated from right atrial appendage of neonate (<1month) and adult (
>
40 years) patients. nMSCs were knocked down (KD) for HSF1 gene using CRISPR-CAS9 technique while HSF1 gene was overexpressed (OE) in aMSCs using HSF1 overexpressing lentiviral constructs. Exosome biogenesis was evaluated using nano site technique. We next evaluated effect of HSF1 KD and OE on miRs cargo in nMSCs and aMSCs respectively. Exosome acquisition by target cells was studied by mCherry labeling technique. The potential of nMSCs and aMSCs and their corresponding exosomes to repair rat ischemic heart was evaluated under the effect of HSF1 KD and OE.

Results:
HSF1-KD in nMSCs resulted in significant reduction in production of exosomes, downregulation of ESCRT complex genes and therapeutic miRs viz, miR-199a, mi590-3P and miR-146. In contrast, HSF-1 over expression in aMSCs statistically increased production of exosomes, ESCRT complex genes and of therapeutic miRs. Moreover, HSF-1 OE in aMSCs resulted in statistical downregulation of miR-122, known to induce apoptosis, and downregulation of p27, a known target of miR-590. We identified that potential of nMSCs to repair ischemic heart decreased statistically after HSF1-KD while that of aMSCs increased significantly after HSF1-OE. Finally, we identified exosomes from these stem cells were preferentially taken up by cells in injured myocardium and not by cells in non-injured one and that HSF1-OE increased the uptake by recipient cells while HSF1-KD had opposite effect.

Conclusion:
Together, our results demonstrate that HSF-1 plays an important role in exosome biogenesis, miRs cargo enrichment and uptake of exosomes by recipient cells.
Abstract 9278: No Improvement in the Operative Outcomes of Women Undergoing Coronary Artery Bypass Surgery in the United States, 2011-2020
Authors: Gaudino Mario F , Chadow David M , Rahouma Mohamed , Soletti Giovanni , Sandner Sigrid , PEREZGROVAS OLARIA ROBERTO , Audisio Katia , Cancelli Gianmarco , Bratton Brenden , Fremes Stephen E , Kurlansky Paul , Girardi Leonard N , Habib Robert H
Published: June 2023

Background:
Women undergoing coronary artery bypass grafting (CABG) have significantly higher mortality and morbidity compared to men. While on a national level overall mortality after CABG has significantly decreased over the last decade, it is unclear if this trend of improvement applies to women.

Objective:
The aim of this analysis was to evaluate trends in outcomes of women undergoing CABG in the United States over the course of the last decade.

Methods:
The data for this study was provided through the STS Participant User File research program. Patients were included in the analysis if they underwent primary isolated CABG during the study period. Patients requiring resuscitation prior to surgery, emergent/salvage operations, and reoperation were excluded. The primary outcome was operative (30-day) mortality. The secondary outcome was the composite of operative mortality and morbidity (including operative mortality, stroke, renal failure, reoperation, deep sternal wound infection, prolonged mechanical ventilation, prolonged hospital stay). For all the outcomes, the STS definitions were used. The attributable risk (the effect of female sex on CABG outcomes) for the primary and secondary outcomes was calculated.

Results:
Between 2011 and 2020, 1,297,204 patients underwent multivessel CABG, 317,716 (24.5%) of which were women. The proportion of women decreased from 26.2% in 2011 to 22.7% in 2020 (P for trend <0.001). Women had a higher unadjusted operative mortality (2.8% vs 1.7%, P <0.001) and overall unadjusted incidence of the composite of operative mortality and morbidity (22.9% vs 16.7%, P <0.001) compared to men. The attributable risk of female sex for operative mortality varied from 1.28 in 2011 to 1.41 in 2020, with no significant change over the study period (P for trend=0.37). The attributable risk for the composite of operative mortality and morbidity was 1.08 in 2011 and 2020, with no significant change over the study period (P for trend=0.71).

Conclusion:
Female sex remains an independent risk factor for adverse outcomes following CABG and no significant improvement has been seen over the course of the last decade. Further investigation into the determinants of operative outcomes in women is urgently needed.
Abstract 9313: Association Between Polypharmacy and the Risk of Mortality Among Patients With Heart Failure Following Hospitalization: A Nested Case-Control Study
Authors: Boivin Proulx Laurie-Anne , Dorais Marc , Perreault Sylvie
Published: June 2023

Introduction:
Heart failure (HF) is associated with morbidity, hospital readmission and polypharmacy. The risk of mortality in HF patients exposed to polypharmacy is poorly studied. We examine the association between polypharmacy and mortality in HF patients.

Methods:
Using hospitalization and drug databases, we assembled a cohort of HF patients having been hospitalized and then discharged to the community between 1999 and 2015 in Québec, Canada. Polypharmacy, cardiovascular (CV) polypharmacy and non-CV polypharmacy were respectively defined as exposure to ≥10 drugs, ≥ 5 CV drugs and ≥ 5 non-CV drugs in the 3-month prior to the case or the date of control selection. We conducted a nested case-control study to estimate rate ratios (RR) of all-cause mortality using a multivariate conditional logistic regression at 1-year of follow-up. Cases and controls were matched for age at baseline, sex, and time of hospitalization.

Results:
We identified 12,242 HF patients with a mean age of 81.6 years. Neither CV polypharmacy (adjusted RR 0.97; 95% CI 0.82-1.15) nor non-CV polypharmacy (adjusted RR 0.93; 0.77-1.12) were related to a lower mortality risk (Figure 1). However, polypharmacy (adjusted RR 1.33; 1.07-1.61) showed an association with mortality risk. Myocardial infarction, valvular disease, peripheral artery disease, diabetes, major bleeding, chronic kidney disease, high comorbidity score, high frailty score, hydralazine and spironolactone use were associated to a greater risk of mortality ranging from 15% to 63%, while use of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, β-blockers, statins, oral anticoagulant, antiplatelets were associated to lower risk of mortality ranging from 14 to 32%.

Conclusion:
The study suggests that polypharmacy was related to all-cause-mortality, and well recognized CV medication were associated with a lower mortality risk.
Abstract 9318: The Safety, Pharmacokinetics, Pharmacodynamics and Immunogenicity of Ebronucimab in Healthy Volunteers: Result From a Phase I, Randomized, Double-Blind, Placebo-Controlled, Single Dose-Escalation Study
Authors: Chen Rui , Tian Zhuang , Tang Xiange , Hu Pei , Wang Lvya , Xia Yu , Li Baiyong , Wang Max , Ni Xiang , Wang Guoqin , Zhang Shuyang
Published: June 2023

Introduction:
Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors have demonstrated to be effective therapeutic agents for lowing low-density lipoprotein cholesterol (LDL-C). Ebronucimab (AK102) is a novel fully human immunoglobulin G1 (IgG1) monoclonal antibody against PCSK9. The objective of this study is to investigate the safety and tolerability of ebronucimab in healthy subjects.

Methods:
A total of 32 healthy adult subjects were planned to be enrolled and treated in a dose escalation manner. In each cohort, 8 subjects were randomized in a 3:1 ratio to receive a single dose of ebronucimab (75, 150, 300 or 500 mg) or matching placebo via subcutaneous injection (Figure 1). Blood was drawn at pre-selected timepoints to evaluate the pharmacokinetic parameters, free PCSK9 concentration and anti-drug antibody (ADA). Safety assessment was carried out up to day 85 ± 3 or early termination visit.

Results:
Safety Among the 32 subjects recruited, 87.5% (21/24) subjects administrated ebronucimab and 75% (6/8) subjects treated with placebo reported treatment emergent adverse events (TEAEs). The majority of adverse events were mild and moderate in severity. No relationship was identified between the dose of ebronucimab and the incidence of TEAEs. No TEAEs leading to study discontinuation and death were reported.
Pharmacokinetics (PK)/Pharmacodynamics (PD)
Following a single subcutaneous injection of 75 mg to 500 mg ebronucimab in healthy subjects, the median of T
max
ranged from 2.0 to 6.0 days and t
1/2
was within 4.11 to 5.01 days across cohorts. C
max,
AUC
0-t
,
and AUC
0-∞
increased approximately in a dose-proportional manner, see Table 1 and Figure 2. Serum free PCSK9 was almost completely inhibited after ebronucimab injection. The lowest level of free PCSK9 was observed around 2 days post administration and maintained at a low level 14-22 days post injection, see Figure 3.
Immunogenicity
A total of 3 subjects were tested ADA positive at least once during the study (75 mg, 1 subject; 500 mg, 2 subjects). The incidence of ADAs in subjects treated with ebronucimab was 12.5 % (3/24).

Conclusions:
Ebronucimab was well tolerated in healthy subjects and no special safety signal was identified during the study.
Abstract 9349: Procedural Characteristics of Intravascular Ultrasound-Guided Percutaneous Coronary Intervention and Their Clinical Implications
Authors: Lee Seung-Yul , Zhang Junjie , Mintz Gary S , Chen Shao-Liang , Hong Myeong-Ki
Published: June 2023

Introduction:
Despite the clinical benefits to intravascular ultrasound (IVUS) guidance for percutaneous coronary intervention (PCI), most patients with coronary artery disease undergo angiography-guided PCI alone in real world.

Hypothesis:
We sought to investigate the procedural characteristics of IVUS-guided PCI and their clinical outcomes, as compared with angiography-guided PCI.

Methods:
This was a cohort study using patient-level data from IVUS-XPL and ULTIMATE clinical trials. A total of 2,848 patients with 3,872 native coronary lesions were included and procedural characteristics assessed by quantitative coronary angiography (QCA) were compared between IVUS and angiography guidance.

Results:
Stent-to-reference vessel diameter ratio (i.e., QCA stent sizing) was greater (1.11±0.16 vs 1.07±0.14, p<0.001) and high-pressure post-dilation was more frequently performed (83.7% vs 75.4%, p<0.001) with IVUS guidance, whereas residual stent edge dissections were more frequent in lesions treated with IVUS guidance (4.6% vs 0.7%, p<0.001). Given the dissection risk, optimal QCA stent sizing for IVUS guidance was a stent-to-QCA reference vessel diameter ratio ≥1.1 to <1.3. Among 1,424 patients (1,969 lesions) treated with angiography guidance, QCA stent sizing <1.0 was observed in 651 (33.1%) lesions while QCA stent sizing ≥1.1 to <1.3 was observed in only 526 (26.7%) lesions. Under angiography guidance, patients with both QCA stent sizing ≥1.1 to <1.3 and high-pressure post-dilation (235/1,424, 16.5%) had a lower risk of 3-year target lesion failure compared with others (hazard ratio=0.532, 95% confidence interval=0.293-0.966, p=0.038).

Conclusions:
IVUS-guided PCI resulted in larger QCA-assessed stent sizing and more frequent post-dilation with high-pressure inflations. These procedures may further improve long-term clinical outcomes in patients undergoing PCI without IVUS.
Abstract 9360:
18
F-Sodium Fluoride Positron Emission Tomography Following Coronary Computed Tomography Angiography in Predicting Major Coronary Events: A 5-year Longitudinal Study
Authors: Kitagawa Toshiro , Sasaki Ko , Fujii Yuto , Ikegami Yuki , Tatsugami Fuminari , Awai Kazuo , Hirokawa Yutaka , Nakano Yukiko
Published: June 2023

Background:
The predictive value of
18
F-sodium fluoride (
18
F-NaF) positron emission tomography (PET) for coronary events has attracted interest. We evaluated the usefulness of
18
F-NaF PET following coronary computed tomography (CT) angiography (CCTA) in predicting major coronary events (CEs) during a 5-year period.

Methods:
This study included 40 patients with ≥1 coronary atherosclerotic lesion detected on CCTA who underwent
18
F-NaF PET/CT. Each lesion was evaluated with luminal stenosis and the presence of high-risk plaque (HRP) defined as plaque with low density (<30 Hounsfield units) and high remodeling index (>1.1). Focal
18
F-NaF uptake in each lesion was quantified using maximum tissue-to-background ratio (TBR
max
), and maximum TBR
max
per patient (M-TBR
max
) was determined. We followed CEs (cardiac death, acute coronary syndrome, and/or coronary revascularization >6 months after
18
F-NaF PET/CT scan) for 5 years.

Results:
A total of 142 coronary lesions were analyzed. Eleven patients (28%) experienced any CE: 1 had sudden cardiac death, 1 had myocardial infarction, 3 had unstable angina requiring hospitalization, and 6 underwent late coronary revascularization. The frequencies of ≥70% stenosis (64% vs. 55%, p = 0.63) and HRP (83% vs. 62%, p = 0.23) on CCTA were not different between patients with CE and those without. Patients with CE showed a higher M-TBR
max
(1.40 ± 0.19 vs. 1.18 ± 0.18, p = 0.0011), and its optimal cutoff to predict future CE was 1.29 (area under curve 0.79). Patients with ≥1.29 M-TBR
max
had a higher risk of CE than those without (Fig 1), whereas patients with ≥70% stenosis and those with HRP did not (Fig 2). Multivariate Cox proportional analysis adjusted for age, sex, the presence of coronary risk factors, and CCTA findings showed that ≥1.29 M-TBR
max
remained as an independent predictor of the 5-year CE (hazard ratio, 5.4; 95% CI, 1.1-25.4; p = 0.034).

Conclusions:
18
F-NaF PET following CCTA has a promising potential to predict long-term CEs.