bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 15812: Assessing the Effect of the Unos Heart Allocation Policy Change on Ohtx and Lvad Access and Outcomes
Authors: Fox Daniel K , Waken RJ , Fanous Erika , Wang Fengxian , Wolfe Jonathan , Robbins Keenan , Joynt Maddox Karen E
Published: June 2023

Introduction:
In October 2018, the heart allocation policy for adult heart transplant (OHTx) in the United States was changed, with the goal of reducing waitlist mortality and providing broader sharing of donor organs within the United States. The aim of this study was to assess the effect of this policy change on access to OHTx vs LVAD, overall and among key sociodemographic subgroups, in the US from 2016 to 2019.

Hypothesis:
We hypothesized that the UNOS heart allocation policy would increase OHTx volume overall as well as use of temporary mechanical circulatory support.

Methods:
We identified all patients receiving OHTx or LVAD between 2016-2019 using the National Inpatient Sample. Controlling for medical comorbidities, trends over time, and within hospital-year effects, we fit a dynamic logistic regression model to evaluate patient and hospital factors associated with receiving OHTx vs LVAD pre- versus post-policy change.

Results:
We identified 2264 patients who received OHTx and 3157 who received LVADs during the study period. Overall, there was a 4.16% increase in OHTx receipt, compared to LVAD, in the post-period (p=0.006). Among OHTx recipients, the frequency of use of tMCS changed from 15.61% in the pre period to 42.55% in the post period (p-value < 0.0001). While the policy change was associated with differences in the odds of receiving an OHTx versus LVAD between different regions of the country, there were no significant changes based on age, gender, race/ethnicity, insurance status, or rurality.

Conclusions:
The UNOS policy change on access to OHTx was associated with slightly higher rates of OHTx overall, and higher rates of use of temporary support prior to transplant, but no differential change in access among key demographic groups. Shifts in regional allocation were not significant overall, though certain regions appeared to have a relative increase in their use of OHTx.
Abstract 15832: Optogenetic Stimulation of Intrinsic Cardiac Autonomic Neurons Reveals the Interaction Between Catecholaminergic and Cholinergic Pathways
Authors: Russo Rebekah D , Moreno Angel R , Mendelowitz David , Kay Matthew W
Published: June 2023

Autonomic tone, through the interaction of catecholaminergic and cholinergic pathways, is a powerful modulator of cardiac function. Until recently, selective activation of cardiac autonomic pathways has required administration of exogeneous neurotransmitters or careful placement of electrodes to stimulate specific neural populations. Optogenetics enables broader exploration of autonomic interactions through the selective expression of channelrhodopsin (ChR2) in neural populations. Our objective was to simultaneously activate catecholaminergic and cholinergic pathways, by exogenous perfusion of neurotransmitter and photostimulation of opposing autonomic neurons, to test the hypothesis that simultaneous activation will reveal the fast kinetics of cholinergic modulation of catecholaminergic increases in heart rate (HR). Norepinephrine (NE) and acetylcholine (ACh) were administered to perfused transgenic mouse hearts that expressed ChR2 within sympathetic tyrosine hydroxylase neurons (TH+ChR2) or parasympathetic choline acetyltransferase (ChAT+ChR2) neurons. Intrinsic neurons were photostimulated by illuminating the SA node with a 465nm high power microLED. The ECG was recorded to measure beat-to-beat changes in HR. Moderate doses of exogeneous NE increased HR 26.77±5.61% (n=3) and high doses increased HR 59.74±8.77% (n=3). At all NE doses, photostimulation of ChAT+ChR2 neurons immediately reduced HR to values equivalent to, or lower than, pre-NE HR. Arrhythmias were not observed. In companion studies, moderate doses of exogeneous ACh reduced HR 19.98±4.68% (n=7) and high doses reduced HR 51.31±4.07% (n=7). HR increases caused by TH+ChR2 neuron photostimulation were diminished by exogenous ACh in a dose-dependent manner. Increased dosing of exogeneous ACh, with simultaneous TH+ChR2 neuron photostimulation, dramatically shortened the onset of 2
nd
degree AV block and increased its severity. At high concentrations of exogeneous ACh, non-sustained arrhythmias were observed upon the cessation of TH+ChR2 neuron photostimulation. These results provide new insight into the kinetics of intrinsic cardiac autonomic interactions and reveal powerful modulation of catecholaminergic activity by cholinergic activation.
Abstract 15834: Joint Associations Between Resting Heart Rate and Blood Pressure on All-Cause Mortality
Authors: Parikh Trishna , Islam Sumaiya , Akhtar Moizz , Hameed Fariha , Nagaraj Bharath , Visaria Aayush
Published: June 2023

Introduction:
Both blood pressure and heart rate (HR) are important factors that constitute hemodynamic status.

Hypothesis:
We aimed to determine whether HR was independently associated with all-cause mortality and whether HR modified the association between systolic blood pressure (SBP) and all-cause mortality.

Methods:
We included adults aged ≥20 years from the 1999-2018 National Health and Nutrition Examination Surveys without cardiovascular disease, chronic kidney disease, chronic obstructive pulmonary disease, cancer, asthma, or beta blocker use. Resting HR was categorized into 10 beats-per-min increments, and SBP in 10-20 mmHg increments as shown in Table 1. Our primary outcome was all-cause mortality, determined using linkage to the National Death Index through 2019. We used multivariable Cox regression, stratified by HTN status and adjusted for the survey design.

Results:
Among 27,369 participants, 5984 (22%) had diagnosed HTN. A HR ≥80 was associated with at least a 30% increase in mortality risk, regardless of HTN status (Table 1). Among normotensive participants, a HR ≥80 was associated with higher mortality risk compared to HR <80 at all SBPs except for SBP ≥180 (Table 1). While there was significant interaction between continuous HR and SBP on all-cause mortality (p=0.02), there was no evidence of significant effect modification within individual SBP categories.

Conclusions:
A HR ≥80 was independently associated with increased all-cause mortality risk, regardless of HTN diagnosis. HR may be a surrogate for cardiorespiratory fitness. Further studies understanding the joint associations between SBP and HR are needed in both normotensive and hypertensive individuals.
Abstract 15847: Mass Cytometry Reveals Immune Cell Subtypes Responsive to Il-1b and Il-6 Stimulation in CAD Subjects and Controls
Authors: McParland James , Cochran Jesse , McSkimming Chantel , Kothari Hema , Murach Maria , Hosadurg Nisha , Patel Toral , Bekiranov Stefan , Villines Todd , McNamara Coleen A
Published: June 2023

Introduction:
Inflammation plays a key role in the development of atherosclerosis, yet targeted therapies are lacking. Previous trials have demonstrated that IL-1b is a potential target, albeit with adverse effects on immune suppression. IL-6 has emerged as another mediator of coronary artery disease. It clear that a strategy to identify a biomarker customized for inflammatory inhibition is needed. Mass cytometry shows promise as a technology for customized biomarker identification.

Hypothesis:
A mass cytometry panel including markers to identify circulating immune subtypes in humans and phosphorylation of key transcription factors driving downstream inflammation can identify cell subtypes most responsive to cytokine stimulation.

Methods:
Peripheral blood mononuclear cells (PBMCs) were isolated from patients undergoing coronary computed tomography angiography (CCTA). Using PBMCs from 12 pairs of matched subjects, we stimulated cells with vehicle, IL-6, and IL-1b. These samples were analyzed using a custom mass cytometry panel.

Results:
Mass cytometry analysis of PMBCs after 15 minute cytokine stimulation identified specific lymphocyte and monocyte subtypes that were particularly responsive to IL-1b and IL-6. Notably, there was clear heterogeneity in this response suggesting this approach may identify those most impacted by cytokine inhibition or those with most severe disease.

Conclusions:
High dimensional mass cytometry has the potential to better identify individuals at risk and those that may respond to cytokine inhibition. We are in the process of performing advanced bioinformatic analysis including machine learning to leverage this novel technology for precision medicine.
Abstract 15858: Increased T Wave Amplitude in Lead Avr is a Strong Predictor of Reduced Left Ventricular Ejection Fraction in Suspected Acute Coronary Syndrome
Authors: Ahmad Abdullah , Daoud Majd , Faramand Ziad , Al-Zaiti Salah S
Published: June 2023

Introduction:
Non-invasive screening tools of cardiac function can play a significant role in the initial triage of patients with suspected acute coronary syndrome. Numerous ECG features have been previously linked with cardiac contractility in the general population. We sought to examine the prognostic value of positive T wave in lead aVR as a simple marker for real-time screening of reduced left ventricular ejection fraction (LVEF) in suspected acute coronary syndrome.

Methods:
We performed a secondary analysis of a prospective, observational cohort study of patients evaluated for suspected acute coronary syndrome. The parent study recruited consecutive patients evaluated at the emergency department of three UPMC-affiliated tertiary care hospitals. We included consecutive patients in whom an echocardiogram was performed during indexed encounter. LVEF were retrieved from the cardiologist-signed report. Baseline 12-lead ECGs were preprocessed using manufacturer specific algorithms. Amplitude of T wave in lead aVR were automatically measured at T peak in millivolts. Data analysis was performed using SPSS and alpha was set at 0.05 for two-sided hypothesis testing.

Results:
Our sample included 313 patients (aged 63 ± 15, 45% females, 35% Black). The mean LVEF was 57±13%. Most patients were in normal sinus rhythm (87%) or atrial fibrillation (13%). In Bivariate analysis, there was a significant and negative correlation between T wave amplitude in lead aVR and LVEF (Pearson r = -0.173, p = 0.002). T wave amplitude in lead aVR was significantly larger in patients with LVEF < 35% compared to their counterparts (-65±185 vs. -165±180, t(311) = -3.18, p = 0.002).

Conclusions:
Increasing T wave amplitude in lead aVR indicates lower LVEF in suspected acute coronary syndrome. This feature constitutes a simple visual marker to aid clinicians in identifying those with impaired cardiac function during emergency care.
Abstract 15873: Trends, Predictors, and Cardiovascular Outcomes Among Primary vs Secondary Takotsubo Syndrome - Nationwide Inpatient Sample Analysis
Authors: sattar yasar , Titus Anoop , Shahid Izza , Song David , Khan Muhammad Z , Jain Akhil , Ashraf Shoaib , Jalil Mariam , Sulaiman Samian , Khan Muhammad U , balla sudarshan
Published: June 2023

Introduction:
Takotsubo Syndrome (TTS), also known as stress-induced cardiomyopathy can be primary/idiopathic or secondary to physical stressor including acute illness. There is limited data on cardiovascular outcomes among primary TTS (pTTS) and secondary (sTTS).

Methods:
The National Inpatient Sample from the year 2016 to 2019 was queried to assess outcomes in pTTS and sTTS. The primary outcome was all-cause mortality, and secondary outcomes were acute kidney injury (AKI) heart failure (HF), stroke, cardiogenic shock (CS), and sudden cardiac arrest (SCA).We did trend analysis of outcomes, length of stay (LOS) and inflation adjusted hospital charges. The primary analysis used was pearson chi-Square, linear regression, and multivariate matching using STATA 17MP.

Results:
A total of 158,715 patients (pTTS n= 57,560 (38%); sTTS n= 101,155 (62%)). The cohorts were female predominant. On univariate and chi-square linear regression, we found higher odds and incidence of all-cause mortality, AKI, heart failure, and stroke in sTTS as compared to pTTS. After matching for confounding variables, all-cause mortality (OR 1.3; CI 1.1 - 1.56; p < 0.001), and AKI (OR 1.10; CI 1.03 - 1.03; p < 0.001) was still high in sTTS, but interestingly HF (OR 0.93; CI 0.88 - 0.99 ; p = 0.023), stroke (aOR 0.50; CI 0.43-0.59; p < 0.001), and MCS (aOR 0.61; CI 0.47-0.79; p < 0.001) were lower in sTTS as compared to pTTS. There was no difference in CS and SCA between pTTS and sTTS. Self-pay and prior CABG were most predictive of mortality for sTTS. Yearly trend analysis showed an uptrend for all non-HF outcomes in both pTTS and sTTS, a stable trend for HF, while trends showed higher incidence of CS in sTTS as compared to pTTS. Mean LOS and inflation adjusted hospital charges were higher in sTTS compared to pTTS.

Conclusions:
sTTS have worse cardiovascular outcomes as compared to pTTS and associated with higher inflation adjusted hospital charges and length of stay likely due to critical underlying primary illness.
Abstract 15877: Understanding the Mechanisms of Ultrasound-Targeted Microbubble Cavitation-Mediated Blood Brain Barrier Opening
Authors: Conway Grace E , Paranjape Anurag N , Chen Xucai , Villanueva Flordeliza S
Published: June 2023

Introduction:
Stem cell and AAV-gene therapies are exciting new treatments for neuronal regeneration after ischemic stroke, but they have yet to become the standard of care. One challenge for these therapies is penetrating the blood brain barrier (
BBB
). Ultrasound-targeted microbubble cavitation (
UTMC
) using contrast agents (microbubbles,
MB
) and ultrasound (
US
) applied to the brain is being explored to transiently open the BBB. While UTMC-mediated BBB opening is a promising delivery strategy, its underlying mechanisms are poorly understood. We hypothesize that tight junctions (
TJ
) play a role in mediating BBB permeability after UTMC.

Methods:
We utilized transwells with murine brain endothelial cells (
EC
) and astrocytes on opposite sides of a support membrane. US (1 MHz, 10 μs duration, 10 ms pulse interval) at 250 kPa was applied for 20 sec to MB in contact with ECs. Permeability was assessed using dextran. Immunofluorescence with staining for CD-31 (EC) and ZO-1 (TJ) was performed on transwells fixed 15 and 60 min after UTMC. Z-stacks of the transwells were acquired via confocal microscopy to measure paracellular gap area and mean voxel intensity of ZO-1. Data was normalized per EC. Unpaired 2-tailed
t
-test with correction for multiple t-tests were performed.

Results:
UTMC increases dextran flux across the BBB (p<0.05). As shown in Figure 1, compared to no UTMC, there is an increase in paracellular gap area per cell (p<0.05). From 15 to 60 min after UTMC, there is a decrease in gap area (p=0.056) and an increase in the mean voxel intensity of ZO-1 per EC (p<0.05).

Conclusions:
UTMC increase BBB permeability through paracellular gaps. Between 15 and 60 min after UTMC, there is closure of some paracellular gaps and a re-establishment of endothelial TJ in this model of the BBB. Understanding the mechanisms mediating the changes in the BBB after UTMC should facilitate the development of UTMC as a delivery strategy for cell or gene-based therapeutics to enhance recovery after stroke.
Abstract 15900: Impact of Age on Readmission Following Mitraclip; National Readmission Database
Authors: Sharp Dimitri Demetrio , Becerra Benjamin J , Lynch Donald
Published: June 2023

Transcatheter mitral valve repair with the Mitraclip device has become a therapeutic option for patients with moderate to severe mitral regurgitation (MR) and high surgical risk. There are limited data evaluating Mitraclip outcomes in younger patients, although limited studies suggest decreased mortality in younger patients. As severe MR has increasing become recognized in younger patients, there is a need to investigate outcomes with Mitraclip in these subjects. Based on limited available data, our hypothesis was adverse clinical outcomes, including readmission, would be significantly lower among younger subjects following Mitraclip. The National Readmission Database (NRD) for 2018 and 2019 was queried to identify patients undergoing transcatheter mitral valve repair using ICD-10 procedure code ‘02UG3JZ’. Patients were stratified into 3 age groups: < 65, 65-80, and > 80 years of age (yoa) for comparison of readmission rates and risk factors. A total of 9742 who underwent Mitraclip were included in the study. The mean age of included subjects was 77 yoa, and 56 % were male. Approximately 16% had diabetes, 70% had hypertension, and 27% had chronic lung disease. Approximately 87% of subjects had Medicare coverage, while 3% had Medicaid, and 8% had private insurance. Approximately 90% of patients were cared for in 90% teaching hospitals. The overall rate of readmission following Mitraclip was 14%. While there was no difference in readmission by sex for subjects < 65 or > 80, there was a significant increase in readmission for women in comparison to men who were 65-80 yoa (15.8 vs. 12.4%, P < 0.01). There was a significant decrease in rate of readmission for subjects > 80% in 2019 in comparison to 2018 (13.1 vs. 15.5%, P = 0.03). There was significant increase in readmission to teaching hospitals in comparison to non-teaching hospitals for individuals < 65 (15.0 vs. 9.8%, P < 0.01). Rate of readmission was significantly higher for individuals > 80 and 65-80 yoa with chronic lung disease (17.7 vs 13.1%, P < 0.01). For all studied age groups, uncontrolled hypertension was associated with increased rate of readmission (P <0.02). Our studies suggest overall similar outcomes for younger patients undergoing Mitraclip in comparison to other populations.
Abstract 15906: The Role of Different Anticoagulants in the Setting of Heart Failure With Preserved Ejection Fraction (hfpef) and Atrial Fibrillation
Authors: Ibrahim Rand , Mekhael Mario , Lim Chan Ho , Dagher Lilas , Chouman Nour , El Hajjar Abdel Hadi , Noujaim Charbel , Marrouche Nassir
Published: June 2023

Introduction:
The prediction of morbidity and mortality by various anticoagulants in the setting of AF has been well described, its relevance has not been investigated in the subset of patients with HFpEF. We sought to delineate the effect that different anticoagulation regimens (DOACs vs warfarin) carry on the risk of ischemic strokes and death in AF and HFpEF.

Methods:
The ReachNet national registry for Medicare patients was used. The diagnosis of AF was determined using ICD-9 and ICD-10 codes. A total of 737 patients who had AF had a diagnosis of HFpEF. Survival analyses were conducted to predict time-to-stroke and time to death. The role of different anticoagulants was then assessed using Cox-regression analysis while adjusting for covariates (age, sex, BMI, smoking, HT, DM, CAD, history of malignancy).

Results:
The cohort (58.6% males) had an average age of 65 ± 10 years. Comorbidities included HTN (80%), DM (50%), CAD (48%), history of ischemic stroke (5%), and obesity (51%). Of patients on anticoagulation, the majority were on warfarin (51.4%) with the remaining 48.6% on DOACs. Median time to stroke formation was 18 ± 2 months, while that for all-cause mortality was 10 ± 2 months. Females had significantly higher incidences of stroke (OR=6.7, p<0.01). Additionally, patients receiving DOACs were 3.7 times more likely to experience stroke (p<0.01), but anticoagulation regimen did not predict mortality in logistic regression analysis. Cox-regression analysis assessing incidence of ischemic stroke revealed no difference between the different anticoagulation regimens (HR=0.243). In the prediction of all-cause mortality, however, the use of DOACs was associated with a 15-fold increased risk of death compared to the use of warfarin alone (p<0.001).

Conclusions:
AF patients suffering from HFpEF are a vulnerable population at great risk of ischemic strokes and a short life expectancy. Although unadjusted analysis predicts a higher incidence of strokes with the use of DOACs, this did not translate to the prediction of strokes in the long-term. All-cause mortality, however, seems to be reduced to a great extent in the setting of long-term warfarin administration.
Abstract 15927: Decaaf II Sub-Analysis: Effect of Catheter Ablation on Qol in Patients With Persistent AF
Authors: Chouman Nour , Lim Chan Ho , Mekhael Mario , Noujaim Charbel , El Hajjar Abdel Hadi , Dagher Lilas , Marrouche Nassir
Published: June 2023

Introduction:
The 36-item short form health survey (SF-36) is a reliable and validated questionnaire able to assess patients’ overall health & QOL post catheter ablation (CA). Objective: To evaluate the impact of CA on overall health & QOL, in patients with persistent AF 12 months post ablation.

Methods:
In a population of 784 patients with persistent AF, the SF-36 questionnaire was measured at baseline (pre-ablation) and 12 months post-ablation. As per the RAND 36-Item health survey 1.0 scoring method: For each of the categories of the SF-36 (as listed in table 1), answers were scored from 0 to 100 (with higher scores reflecting better health and QOL). The average score was then calculated for each sub-category. Mann Whitney test was used to compare pre with post-ablation score results for each sub-category. Results were presented as mean ± SD. P value < 0.05 was considered significant.

Results:
SF-36 measurement 12 months post-CA showed significantly improved results in all categories of SF-36 QOL assessment in comparison to baseline : Physical functioning ( 80 Vs 67 P< 0.001 ), limitations due to physical health (76 Vs 52 P< 0.001 ), limitations due to emotional problems ( 85 Vs 75 P< 0.001 ), energy/fatigue ( 64 Vs 50 P< 0.001 ), emotional well-being ( 78 Vs 72 P< 0.001 ), social functioning ( 88 Vs 79 P< 0.001 ), pain ( 82 Vs 78 P< 0.001 ), and general health ( 69 Vs 59 P< 0.001 ). (table 1.)

Conclusion:
Cather ablation significantly improved all categories of QOL in patients with persistent AF.
Abstract 165: 21% Or 100% Oxygen During Cardiopulmonary Resuscitation in Asphyxiated Pediatric Piglets - A Randomized Controlled Animal Study
Authors: Nyame Solomon , Cheung Po-yin , Lee Tze Fun , OReilly Megan , Schmolzer Georg
Published: June 2023

Background:
Current pediatric resuscitation guidelines recommend 100% oxygen (O
2
) during cardiopulmonary resuscitation (CPR), however the most effective O
2
concentration for pediatric patients remains unknown.
Aim:
To determine if 21%O
2
during CPR with either chest compression (CC) during sustained inflation (SI) (CC+SI) or continuous chest compression with asynchronized ventilation (CCaV) will reduce time to return of spontaneous circulation (ROSC) compared to 100%O
2
in pediatric piglets with asphyxia-induced cardiac arrest.

Methods:
Piglets (20-23 days of age, weighing 6.2-10.2 kg) were anesthetized, intubated, instrumented, and exposed to asphyxia. Cardiac arrest was defined as mean arterial blood pressure <25 mmHg with bradycardia. After cardiac arrest, piglets were randomized to CC+SI or CCaV with either 21% or 100%O
2
or sham. Heart rate, arterial blood pressure, carotid blood flow, and respiratory parameters were continuously recorded.

Results:
There were no differences in baseline parameters or the duration and degree of asphyxiation. Median (interquartile range) time to ROSC was 107 (90-440) and 140 (105-200) sec with CC+SI 21% and 100%O
2
and 600 (50-600) and 600 (95-600)sec with CCaV 21% and 100%O
2
(p=0.27). Overall, 6 (86%) and 6 (86%) with CC+SI 21% and 100%O
2
and 3 (43%) and 3 (43%) achieved ROSC with CCaV 21% and 100%O
2
(p=0.13).

Conclusions:
In pediatric piglets resuscitated with 21% oxygen compared to 100% oxygen, using either CCaV or CC+SI had similar time to ROSC and survival. CPR using CC+SI had shorter time to ROSC and higher survival compared to CCaV. Clinical studies comparing 21% with 100%O
2
during pediatric CPR are warranted.
Abstract 178: Development And Validation Of The Utstein-based Machine Learning Algorithms To Predict Neurological Outcomes After Out-of-hospital Cardiac Arrest: A Retrospective Analysis Of The Pan-asian Registry
Authors: Lu Tsung-Chien , Wang Chih-Hung , Chou Fan-Ya , Chou Eric H , Tsai Chu-Lin , Ma Matthew Huei-Ming
Published: June 2023

Introduction:
The proportion of favorable neurologic outcome from the survival after Out-of-Hospital Cardiac Arrest (OHCA) remains poor, esp. in the Asian communities. By using the machine learning (ML) approach, we aimed to develop and validate the the Utstein-based ML algorithms to predict neurological outcomes after OHCA in this population.

Methods:
We conducted a retrospective analysis of data collected from the registry of Pan Asian Resuscitation Outcomes Study (PAROS) Network, an international and multi-center cohort study of OHCA across 13 countries in this region. All adult (≥ 18 years) EMS-treated OHCA patients between Jan 2009 to May 2018 in the registry were included, with variables followed the Utstein recommendations and conform to a unified taxonomy established by the network. The primary outcome was defined as good neurological outcome with cerebral performance category 1 or 2. Random splitting was used to divide the dataset into the training/validation and testing cohorts at around 2-to-1 ratio. Four supervised ML models, including Random Forest (RF), Gradient Boosting (GB), Extra Trees (ET), and CatBoost (CB) classifiers were employed to construct the prediction models, and performances were evaluated and compared with traditional logistic regression (LR) by the area under the receiver operating characteristic curve (AUC) in the testing cohort.

Results:
We included 194,300 records for analysis. Of them, 6,342 (3.3%) achieved good neurologic outcome. Among the constructed ML models, RF obtained the best AUC performance (0.924, 95% CI: 0.917-0.932), followed by ET (0.922, 95% CI: 0.915-0.930), CB (0.922, 95% CI: 0.915-0.930), and GB (0.910, 95% CI: 0.901-0.920). Although there was no difference in performance between each ML models, RF performed significantly better than using the traditional LR. The top important features were first arrest rhythm, age, witnessed by EMS, event location, and duration from call to EMS arrival.

Conclusions:
The ML approach showed excellent discriminatory performance to predict good neurologic outcome for EMS-treated OHCA patients in the Pan-Asian communities. It has the potential to save more life or provide termination-of-resuscitation if successfully implemented in the EMS system.
Abstract 182: The Incidence And Indication For Palliative Care Consultation In A Cohort Of Out Of Hospital Cardiac Arrest Patients
Authors: Becker Lauren , Shelton Shelby , Presciutti Alex , Mayer Katherine , Matlock Dan D , Perman Sarah M
Published: June 2023

Introduction:
The indications for palliative care consultation are varied and integration of palliative care is often left to physician discretion. We sought to describe the population of post-arrest patients who receive a palliative care consultation and identify common indications for the consultation.

Methods:
Our study is a single center retrospective chart review from the Colorado Cardiac Arrest Registry (CCAR) including 541 patients admitted to the ICU after OHCA. Data abstracted included race, sex, preferred language, age, placement of a palliative care consult and number of palliative care meetings. A chi-squared test was used to determine statistical significance with a cutoff p value <0.05. Each palliative care consultation was reviewed and the indication for palliative care consultation was coded using thematic analysis.

Results:
Of the 541 patients in the study sample, a palliative care consult order was placed for 73 (13.5%) patients and 55 (10.2%) patients had at least one documented palliative care meeting. Code status changed after the first palliative care meeting in 4 patients. When comparing men to women, 15% of men and 11% of women received a consult. A consult was placed in 18.7% of patients identifying as Hispanic, compared to 13.9% in white patients and 12.6% in black patients. In patients whose preferred language was not English or Spanish, 28.6% received a consult compared to 13.5% of patients preferring English or Spanish. None of these differences were statistically significant. The most common themes identified as the indication for the palliative care consultation were 1.) conflict between the physician and family; 2.) low health literacy; 3.) within family discordance on goals of care and; 4.) the need for specialty social work such as assistance with hospice planning.

Conclusions:
Our study found a low incidence of palliative care consultation and more frequent consultation for non-English or Spanish speaking patients, with four major prevailing themes. Further study is needed to better understand and optimize the utilization of palliative care consultation in post-cardiac arrest patients.
Abstract 201: Resuscitation And Hemodynamic Impact Of Aortic Balloon Occlusion And Percutaneous Left Ventricular Assist Device In A Swine Model Of Cardiac Arrest
Authors: Tiba Mohamad H , Nakashima Takahiro , McCracken Brendan , Hsu Cindy H , Gottula Adam , Greer Nicholas , Cramer Traci , Sutton Nadia R , Ward Kevin R , Neumar Robert W
Published: June 2023

Introduction:
Invasive mechanical support by percutaneous left ventricular assist device (pL-VAD) and percutaneous balloon occlusion of the aorta (pAO) during CPR have recently emerged as feasible resuscitation strategies for refractory cardiac arrest. It is unknown if combining pL-VAD and pAO has additive or synergist benefits during CPR.

Hypothesis:
Combined pAO and pL-VAD during CPR will significantly enhance coronary and cerebral perfusion pressure (CoPP, CePP), return of spontaneous heartbeat (ROSHB) rate, and post-ROSHB cardiac function compared to either therapy alone after prolonged cardiac arrest in a swine model.

Methods:
Nineteen swine 52 (3.9) kg; (9 male) were utilized. A pL-VAD (Impella CP®) and a balloon catheter were inserted through the femoral arteries under general anesthesia. Ventricular fibrillation was induced and left untreated for 8 minutes followed by 16 minutes of mechanical CPR (mCPR). Animals were randomized to 3 treatment groups A) pL-VAD (n=6), B) pL-VAD+pAO (n=6), and C) pAO (n=7). Treatment was initiated 24 minutes after arrest. mCPR was continued during treatment. Defibrillation was attempted 3 times starting at minute 28 and then every 4 minutes. Hemodynamics, cardiac function, and blood gases were monitored for 4 hours after ROSHB.

Results:
Following the intervention, CoPP for Group B increased by a mean (SD) of 26 (15) mmHg which is significantly different from both groups A and C, 3.6 (12) and 7.5 (6.3) mmHg (
p
=0.007). CePP increased by 2 (11.5), 18.5 (18.6), and 8.3 (6.8) mmHg for groups A, B, and C with no significant differences (
p
=0.06). The rate of ROSHB was 67% (4 of 6), 83% (5 of 6), and 100% (7 of 7) for groups A, B, and C (
p
>0.05). All groups exhibited similar levels of post-ROSHB recovery including blood pressure, venous oxygen saturation, cardiac output, ejection fraction, and lactate clearance. Total ionotropic and vasopressor support (epinephrine and norepinephrine) was 56 (25), 50 (5), and 81 (90) mcg/Kg in groups A, B, and C (
p
=0.66).

Conclusion:
Combined pAO and pL-VAD resulted in greater improvement of CPR hemodynamics compared to either intervention alone in this model of prolonged cardiac arrest. However, it remains unclear if this translates into better recovery of cardiovascular and neurological function.
Abstract 219: Cerebral Oximetry Shows The Cardiopulmonary Resuscitation Leading To Return Of Spontaneous Circulation
Authors: Salaberria Ruth , LARREA REDIN ANDIMA , ARAMENDI ELISABETE , Cabezas Zoraida , Mugica Edurne M , Arnedo Ander
Published: June 2023

Purpose:
Effectiveness of cardiopulmonary resuscitation (CPR) is associated to return of spontaneous circulation (ROSC), but the alignment of the characteristics of compressions (rate and depth) to AHA recommendations has not been proven to improve outcome. In this study the power of the near infrared spectroscopy to discriminate productive CPR, i.e. chest compression sequences leading to ROSC, was evaluated.

Material and methods:
The cerebral oxygen saturation (rSO
2
) measured in both cerebral lobules was recorded with the Nonin SenSmart 100X oximeter by Emergentziak-Osakidetza, the emergency service of the Basque Country, in the out-of-hospital cardiac arrest (OHCA). Concurrently, the ECG and bioimpedance were recorded by the Lifepak 15 desfibrillator. Chest compressions were delivered by Lucas 2 & Lucas 3 devices. Sequences of compressions longer than 30 s were extracted, and changes in the left (rSO
2,L
) and right (rSO
2,R
) lobes were automatically computed by signal processing. The increase of rSO2, measured every 4 s during the CPR-sequence, was adjusted with linear regression and compared for ROSC/no-ROSC patients as registered in the emergency department (ED).

Results:
Chest compression intervals were identified in the bioimpedance, and 403 CPR-segments were extracted from 115 patients (80 from 43 patients with ED-ROSC) with a mean(std) duration of 2.46(1.07) min. The median(IQR) increase of brain saturation per patient, rSO
2,L
and rSO
2,R
, were 2.1(1.1-5.5) and 1.9(0.9-3.8) points. The figure shows the linear adjustment of the evolutions for both ROSC/no-ROSC groups, with slopes of: 1.81 vs 1.23 min
-1
for ΔrSO
2,L
(p>0.05), 1.78 vs 0.95 min
-1
(p<0.05) for ΔrSO
2,R,
and 2.03 vs 1-08 min
-1
(p<0.05) for the combination of both.

Conclusions:
Cerebral oximetry showed different evolution during mechanical chest compressions for patients with ED-ROSC. Significantly higher slopes in the rSO
2
evolution were observed for patients who achieved ROSC in OHCA.
Abstract 223: Sudden Cardiac Arrest Occurring In The Emergency Department: Prevalence, Unique Features And Survival Outcomes
Authors: Chugh Harpriya , Reinier Kyndaron , Sorenson Chad , Dizon Bernadine , Uy-Evanado Audrey , Jui Jonathan , Chugh Sumeet S
Published: June 2023

Background:
The US national emergency department (ED) sample recently reported unexpectedly low survival from sudden cardiac arrest (SCA) in the ED at 10%. However, detailed, prospective community-based studies have not been conducted, especially for SCAs of likely cardiac etiology.

Hypothesis:
When restricted to ED SCA cases of likely cardiac etiology, survival outcomes are significantly better than reported by the US national emergency department sample.

Methods:
We prospectively ascertained all residents of the Portland, Oregon metropolitan area (2002- 2017) with SCA resuscitation attempted by emergency medical services (EMS) or in area EDs. All cases were required to have SCA of likely cardiac etiology. Detailed reviews were conducted of all available EMS reports and lifetime medical records including ED charts, to construct individual clinical and resuscitation profiles. Comparisons were made between cases who arrested in the ED, public and home locations.

Results:
We identified 4628 SCA cases with mean age 63±18, 69% male. Of these 50 (1.1%) arrested in the ED, 950 (20%) in public places, 2781 (60%) at home and 19% in other locations. ED SCA cases were intermediate in age between public and home locations (public 59±16y vs ED 60±19y vs home 64±19y, p<0.0001) and most likely to be female (ED 38% vs home 34% vs. public 15%, p <0.0001). ED SCA cases were most likely to present with shockable rhythms (ED 73%, public 66%, home 38%, p<0.0001) corresponding with the highest survival rate (ED 41% vs public 29% vs home 13%, p<0.0001). ED SCA patients also presented with the highest prevalence of warning symptoms (n=1748 with symptom information available). The two most common were chest pain (ED 54% vs public 25% vs home 26%, p=0.0003) and dyspnea (ED 44% vs public 24% vs home 34%, p=0.0004).

Conclusion:
In this community, ED SCA of likely cardiac etiology had 4-hold higher survival compared to the national sample, and was also observed to have unique features compared to SCA in other locations. Given the likely diverse nature of ED SCA, it would be worth considering reporting based on likely SCA etiology.
Abstract 234: Increased Likelihood Of Survival For Patients Presenting With Non-shockable Cardiac Arrest And Treated With A Device-assisted Head-up CPR Bundle
Authors: Bachista Kerry , Labarere José , Moore Johanna C , Quinn Ryan , Parquette Brent , Emanuelson Lauren , Lick Charles , Lurie Keith G , Debaty Guillaume , Pepe Paul E
Published: June 2023

Introduction:
Despite receiving conventional (C) CPR and other standard treatments, almost all out-of-hospital cardiac arrest (OHCA) patients with non-shockable presentations will still die. As non-shockable presentations comprise nearly 80% of all OHCA cases, alternative treatment strategies are clearly indicated.

Hypothesis:
Compared to C-CPR controls, treatment with AHUP CPR (defined as the combination of an automated head up positioning [AHUP] device, an impedance threshold device [ITD], and manual and/or automated suction cup-based CPR), increases the probability of survival (SURV) to hospital discharge as well as neurologically favorable survival (N-SURV) for OHCA patients with (first recorded) non-shockable presentations.

Methods:
Prospectively collected data were obtained from a national AHUP CPR registry from 5 early adopting first responder EMS agencies that routinely initiated immediate AHUP CPR and tracked OHCA outcomes. Comparisons were made to C-CPR controls using individual patient data from high-performing prehospital systems participating in the NIH-funded Resuscitation Outcomes Consortium ROC-PRIMED and ResQTrial studies. AHUP and C-CPR patients presenting with a non-shockable rhythm were matched for the same discrete time interval from the 9-1-1 call to EMS CPR start time and propensity score for the key baseline covariables associated with outcome (e.g., age, sex, bystander-witnessed, bystander CPR) with a 1:1 ratio. Neuro-intact survival was defined as a modified Rankin Scale
<
3 or Cerebral Performance Category 1 or 2.

Results:
AHUP CPR treatment in non-shockable rhythm cases (n=380) was associated with increased unadjusted SURV rates of 7.4% vs 3.1% for C-CPR controls (1,852): Odds ratios (OR) and 95% confidence intervals [CI] = 2.46 [1.33-3.92]. After propensity matching, AHUP CPR was associated with increased SURV and N-SURV vs C-CPR controls: OR[CI] were 2.84[1.35-5.96] and 3.87[1.27-11.78], respectively. Also, the faster AHUP was initiated, the greater the benefit.

Conclusions:
This analysis provides strong clinical evidence of higher likelihood of survival, including favorable neurological function, for the vast majority of OHCA patients who present with a non-shockable rhythm by using AHUP CPR.
Abstract 235: Post-shock Asystole And Inappropriate Shocks In Patients Dying Out-of-hospital While Wearing A Defibrillator
Authors: Berger Justin M , Sengupta Jay , Casey Susan A , Bank Alan J , Sharkey Scott W , Hauser Robert
Published: June 2023

Background:
The LifeVest wearable defibrillator (LWD) is prescribed for patients who are at risk for sudden cardiac death. However, it does not provide backup pacing for post-shock asystole (PS-A) or post-shock bradyarrhythmia (PS-B;<50 bpm). We sought to determine if this limitation may have impacted outcomes in patients treated with the LWD who died out-of-hospital (OOH). Also, we assessed the incidence and clinical consequences of inappropriate shocks (IAS) in these patients.

Methods:
The U.S. Food and Drug Administration's Manufacturers and User Facility Device Experience (MAUDE) database was queried for the manufacturer's descriptions of events and stored ECG findings of patients who died OOH while wearing the LifeVest. Excluded were LWD patients who did not receive a LWD shock during the terminal event.

Results:
From January 2017-March 2022, 543 patients died OOH and received at least one LWD shock (avg 3.9±4.5SD; range 1-34). Of these, 120 (22.1%) had PS-A alone, 26 (4.8%) had PS-B alone, and 85 (15.5%) had both PS-A and PS-B. PS-A first occurred after shock #1 (n=127; 62.0%); shock #2 (n=29; 14.1%); shock #3 (n=18; 8.8%), and shocks #4 to #18 (n=31;15.1%). For the 205 (37.8%) patients who had PS-A with or without PS-B, the rhythms appropriately shocked were ventricular fibrillation (VF; n=121; 59.0%) and ventricular tachycardia (VT; n=63; 30.7%). Of the 184 patients whose initial rhythm was VF/VT, 118 (64.1%) died in asystole after the first and only shock, 40 (21.7%) died in asystole after the second (n=23) or third shock (n=17), and 26 (14.1%) died in asystole after the fourth to eighteenth shock. Twenty-one patients died when asystole occurred after they received IAS for atrial fibrillation (n= 3), supraventricular tachycardia (n= 4), and sinus (n=4) or idioventricular rhythm (n=10). Overall, 70.3% (382/543) of patients received one or more IAS (avg 2.7±2.8SD; range 1-26).

Conclusion:
Post-shock asystole and post-shock bradycardia are common in patients who die after receiving appropriate LWD shocks. Most patients received one or more IAS, and some were lethal. Whether back-up pacing and better rhythm and noise discrimination could improve outcomes warrants investigation.
Abstract 241: Comparison Of A Phone-based Business AED Survey Canvas, 911-Dispatch AED Inventory, And State-Mandated AED Registry In Forsyth County, NC
Authors: Patel Jerishma , Rahim Faraan , Yellanki Sreekanth , Choi Hanul , Simmons Denise , Pun Patrick H , Krychtiuk Konstantin , Granger Christopher , Nelson Darrell , Clark Tyson , Monk Lisa , Mark Daniel B , Starks Monique A
Published: June 2023

Introduction:
In North Carolina (NC), 911-dispatch centers are accelerating treatment to OHCA by notifying bystanders of nearby public AEDs. This system depends on a comprehensive registry of AED locations. State law requires registration of AEDs with the NC Office of EMS (NC OEMS), but adherence to this legislation is unknown. The purpose of this study was to determine the registration status of public AEDs in a large county in NC.

Methods:
Using structured phone surveys, we determined the AED status and information for businesses in Forsyth County, NC. Using a national business database, we identified all registered large businesses (>20 employees) and select small businesses (1-19 employees) most likely to have an AED: healthcare, government, childcare, educational, and religious organizations. In addition, AED lists were elicited from large organizations (e.g non-hospital health clinics, universities, and county government) (n=293 AEDs), NC OEMS (n=336), and 911-dispatch center (n=73).

Results:
Between 1/2/22-5/7/22, we contacted 1,702 businesses (response rate =79.1%). Of these, 411 (30.5%) businesses reported >= 1 AEDs. Additionally, 106 unique AED locations were identified from large organizations; 22 from the 911-dispatch; and 34 from the NC OEMS registry. The final AED list contained 963 AEDs at 573 unique locations (Table). Identified AEDs were most frequently located at health clinics, schools, colleges, offices, industrial facilities, and churches. A majority of AEDs (65.1% [627/963]) were not previously registered in the NC OEMS AED registry. Few business AEDs (11.8% [114/963]) were listed in the county dispatch agency’s geolocation software system.

Conclusion:
Most businesses and organizations in our survey canvas had AEDs that were unregistered in a state-mandated AED registry. Structured strategies to increase reporting of publicly available AEDs to NC OEMS and transfer of that information to county 911-dispatch systems are needed.
Abstract 246: Defibrillation For Pulseless Ventricular Arrhythmias During Pediatric In-hospital Cardiac Arrest: A Report From The AHA Get With The Guidelines
®
-Resuscitation Registry
Authors: Haskell Sarah E , Hoyme Derek , Girotra Saket , Zimmerman M Bridget , Reeder Ron , Raymond Tia T , Samson Ricardo , Berg Marc , Berg Robert A , Nadkarni Vinay M , Atkins Dianne L
Published: June 2023

Introduction:
Approximately 15,200 children suffer an in-hospital cardiac arrest (IHCA) annually, and 10-20% will have ventricular fibrillation or pulseless ventricular tachycardia (VF/pVT). Timely defibrillation is critical for shockable rhythms, however current data are lacking on outcomes when > 1 shock is required for termination of VF/pVT.

Methods:
From the AHA Get With The Guidelines
®
-Resuscitation registry, we identified children < 18 years of age who had IHCA from initial VF/pVT and received > 1 shock from 2000-2020. Patients were analyzed according to total number of shocks received: 2 shocks, 3 shocks, or
>
4 shocks. Multivariable logistic regression models were used to test the association between number of shocks and return of spontaneous circulation (ROSC), survival to hospital discharge, and survival to hospital discharge with favorable neurologic outcome.

Results:
436 patients met inclusion criteria and received > 1 shock for VF/pVT. Median age was 8 years [IQR, 0.9,15.0]. Patients that required
>
4 shocks were older patients (11 years [1.0-15.0; p=0.013]). A higher percentage of patients receiving
>
4 shocks had renal insufficiency (14% vs. 7% for 2 shocks vs. 6% for 3 shocks, p = 0.041). Patients receiving
>
4 shocks vs. 2 shocks were less likely to achieve ROSC (OR 0.40 [0.23,0.68]; p=0.0009). There was no statistically significant difference in survival to hospital discharge for patients receiving 2 shocks (42%), 3 shocks (39%), or
>
4 shocks (32%) or survival to hospital discharge with favorable neurologic outcome.

Conclusion:
There was no significant association between the number of shocks and survival to hospital discharge or survival to hospital discharge with favorable neurologic outcome. ROSC was significantly less in patients with
>
4 shocks for VF/pVT compared to 2 shocks. Further research is needed to characterize energy dosing when > 1 shock is needed for VF/pVT.
Abstract 247: Chest Tube Insertion, Needle Thoracostomy, And Pericardiocentesis During In-hospital Cardiac Arrest
Authors: Andrea Luke , RAHMANIAN MARJAN , Carlese Anthony , Shiloh Ariel , Balakrishnan Rithvik , Soleiman Aron , Gong Michelle , Moskowitz Ari
Published: June 2023

Introduction:
Some causes of cardiac arrest, e.g. cardiac tamponade or tension pneumothorax, can only be reversed by an emergent invasive procedure; identification and treatment of these causes is critical during cardiopulmonary resuscitation. The use of emergent procedural interventions has not been comprehensively studied in the setting of in-hospital cardiac arrest (IHCA).

Methods:
Using the American Heart Association sponsored Get With The Guidelines
®
-Resuscitation registry, we examined adult patients who received an invasive procedure (chest tube insertion (CTI), needle thoracostomy (NT), and/or pericardiocentesis (PC)) during IHCA between 2001 and 2020. Groups were compared using Fisher’s exact test for categorical variables and t-test or rank-sum for continuous variables. Outcomes were compared using multivariate hierarchical modeling accounting for clustering by hospital.

Results:
Of the 482,972 patients with IHCA, 11,304 (2.34%) had a procedure performed (1.24% CTI, 0.46% NT, 0.63% PC). PEA was a more likely initial rhythm in those who received a procedure compared to those who had no procedure (58.2% vs 47.8%, p<0.01), and VT or VF was less likely (8.8% vs 16.9%, p<0.01). Peri-arrest myocardial infarction was more likely in those who received PC compared to no procedure (21.7% vs 15.0%, p<0.01). Those who received CTI or NT were more likely to be on a ventilator than those with no procedure (67.9% vs 49.7%, p<0.01). The mean duration of resuscitation was longer for those with CTI, NT, and PC (29.0 min, 29.0 min, and 33.6 min) than for those who had no procedure (18.6 min, p<0.01). Patients who received CTI, NT, and PC had 7%, 20%, and 27% lower odds of ROSC respectively than patients who had no procedure (aOR 0.93, 95%CI 0.91 - 0.95, p<0.01; aOR 0.80, 95%CI 0.78 - 0.82, p<0.01; aOR 0.73, 95%CI 0.71 - 0.74, p<0.01), and 5%, 10%, and 12% lower odds of survival to discharge (aOR 0.95, 95%CI 0.94 - 0.96, p<0.01; aOR 0.90, 95%CI 0.89 - 0.92, p<0.01; aOR 0.88, 95%CI 0.87 - 0.89, p<0.01).

Conclusions:
We found important differences in patient characteristics and outcomes for those who received invasive procedures compared to those with no procedure. Those who received invasive procedures during IHCA had longer resuscitations but less ROSC and survival to discharge.