bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 31: "Cold" Debriefing After Pediatric In-Hospital Cardiac Arrests
Authors: Wolfe Heather , Wenger Jesse , Sutton Robert , Niles Dana , Nakdarni Vinay , Duval-Arnould Jordan , Sen Anita , Cheng Adam
Published: July 2021

Background:
Cold debriefing(CD) is defined as occurring after at least 1 day to several weeks after a cardiac arrest event. CD has been reported to improve patient survival when implemented in a single institution, however little is known about the nature of cold debriefings across multiple pediatric centers.

Methods:
Retrospective review of prospectively collected data from the Pediatric Resuscitation Quality Collaborative (pediResQ). The collaborative is comprised of 18 institutions in the US and Canada, reporting 283 cardiac arrest events at the time of analysis. We analyzed CD data from in-hospital cardiac arrest (IHCA) events between Feb 2016 and April 2018. Debriefing content was collected with a Plus/Delta framework and qualitative analysis of debriefing comments was performed utilizing a modified Team Emergency Assessment Measurement (TEAM) Framework. The TEAM framework consists of ten categories: leadership, communication, cooperation, team climate, adaptability, situational awareness (SA), prioritization, clinical standards(CS) (e.g. CPR quality), and other. Univariate and regression models were applied accounting for clustering by site.

Results:
CD occurred in 33% (93/283) of IHCA events. Median time to debriefing was 25.5 days [IQR 11, 41] with a duration of 60 minutes [20,60]. Median number of facilitators per event was 1 (IQR 1, 1; range 0, 3). Facilitation and/or co-facilitation was performed by physicians 94%(87/93), nurses 18%(17/93) nurse practitioners 9%(8/93) and other 8%(7/93). Attendance was varied across sites (profession, number per debriefing): physicians 12 [IQR 4, 20], nurses 1 [1, 6], RT 0 [0, 1], administrators 1 [0, 1]. Plus comments were most commonly CS 35%(44/127) of comments, cooperation 21%(27/127) and communication 13%(16/127); Delta comments were CS 31%(41/134), cooperation 18%(24/134) communication 10%(13/134) and SA 9%(12/134). There was no difference in age, sex, race, illness category or survival outcome between events that were debriefed vs. not.

Conclusions:
In a multicenter pediatric IHCA collaborative, cold debriefings were performed after 33% of cardiac arrests. The majority of plus and delta comments could be categorized as clinical standards, followed by cooperation and communication.
Abstract 315: Influence of Previous Comorbidities on Hospital Outcome After Cardiac Arrest
Authors: Dumas Florence , Paoli Audrey , Paul Marine , Llitjos Jean-Francois , Savary Guillaume , Jaubert Paul , Chocron Richard , Varenne Olivier , Charpentier Julien , Mira Jean-Paul , Cariou Alain
Published: July 2021

Introduction:
Despite improvements, overall survival after out-of-hospital cardiac arrest (OHCA) remains low, even in those with return of spontaneous circulation (ROSC). In addition to usual prognostic characteristics, patients’ medical history may also influence the outcome. This study aimed to investigate the role of comorbidities on hospital mortality, neurological outcome and mode of death in OHCA patients with successful ROSC.

Methods:
From Jan 2012 to Sep 2017, all consecutive non-traumatic OHCA adults with stable ROSC admitted in ICU were included. Utstein characteristics, circumstances and in-hospital interventions were prospectively recorded. Comorbidities were measured using Charlson Comorbidity Index (CCI), divided into 3 groups (CCI=0,CCI=1-3,CCI>3).The influence of CCI on mortality and poor neurological outcome at discharge (with a Cerebral Performance Categories level>2) was assessed using logistic regression and association with mode of death (withdrawal of life sustaining treatments (WLST) or other causes) using multinomial regression.

Results:
During the study period, among 777 patients admitted alive and analyzed, 504 (65%) pts were discharged as CPC>2 and 484 (62%) died in ICU with 48%, 61% and 70% in CCI-0, CCI 1-3 and CCI>3 respectively. After adjustment, an increase in CCI was associated with poor neurological outcome (ORadj 2.22 [1.21-4.08] for CCI=1-3 and ORadj=2.86 [1.50-5.45] for CCI>3; ref CCI=0). Other independent predictors were an initial non shockable rhythm (OR=3.70[2.38-5.88]), absence of bystander cardiopulmonary resuscitation (CPR) (OR=1.96[1.20-3.22]), higher dose of epinephrine (OR= 5.88 [3.70-9.09]), longer resuscitation (CA-CPR, OR=1.69 [1.10-2.63] and CPR-ROSC, OR=2.43 [1.56-3.85]). Using multinomial regression, an increased CCI was associated with all modes of death, but particularly with WLST (RRadj=2.43 [1.25-4.71] for CCI=1-3 and 4.27[2.15-8.48] for CCI>3, ref CCI=0).

Conclusion:
A high number of comorbidities, as assessed by CCI, was associated with a worse neurological and a higher mortality in patients admitted alive after cardiac arrest. Presence and burden of comorbidities should be considered in the evaluation of the prognosis in patients admitted after cardiac arrest
Abstract 317: The Clinical Features and Outcomes of Vasospastic Angina in Patients Survived Out-of-Hospital Cardiac Arrest
Authors: You Kyoung Min , Lee Hui Jai , Shin Jonghwan
Published: July 2021

Introduction:
Acute myocardial infarction (AMI) is a major cause of cardiac arrest. Coronary vasospasm has been suggested to play a significant role in the acute phase of MI. Vasospastic angina (VSA) is characterized by spontaneous attacks of chest pain, caused by transient coronary vasospasm. Severe coronary vasospasm might cause AMI, fatal arrhythmia, and subsequent cardiac arrest, however, there have been limited studies about the clinical characteristics and prognosis of patients with VSA regarding cardiac arrest. This study investigated the clinical features and outcomes of VSA compared to other MI in patients survived out-of-hospital cardiac arrest (OHCA).

Method and Results:
We analyzed the data of adult OHCA patients from the prospectively collected post cardiac arrest syndrome (PCAS) registry of 3 urban academic hospitals from December 2013 to December 2017.

During the study period, 721 OHCAs were collected, including 18 diagnosed with VSA and 133 with other MI as primary cause of cardiac arrest. Compared to other MI, more patients achieved pre-hospital return of spontaneous circulation (ROSC) in VSA group (72.2% vs. 47.4%,
p
=0.041). The advanced cardiovascular life support (ACLS) time (median, 4.0 min vs. 10.0 min;
p
=0.008) was shorter in VSA group. The SOFA (5.0 vs. 9.0,
p
=0.007) and APACHE II score (20.5 vs. 25.0,
p
=0.007) at admission were lower in VSA group. The proportion of the patients who underwent coronary angiography (CAG) did not differ between the two groups and there were no patients with a newly diagnosed coronary obstructive lesion in CAG performed after ROSC. More patients in VSA group had good neurologic outcome at hospital discharge (77.8% vs. 47.3%,
p
=0.022), 28 days (76.5% vs. 48.4%,
p
=0.038), and 6 months (76.5% vs. 47.7%,
p
=0.037). All-cause mortality rate at in-hospital (5.6% vs. 42.1%,
p
=0.002) and 28 days (11.2% vs. 44.5%,
p
=0.009) were lower in VSA group. In the subgroup analysis of patients who underwent CAG, more patients with VSA showed lower mortality rate at in-hospital (0.0% vs. 35.4%,
p
=0.003) and 28 days (6.7% vs. 38.0%,
p
=0.019).

Conclusion:
In patients survived OHCA, patients with VSA more achieved pre-hospital ROSC and showed better neurologic outcome and lower mortality rate compared to those with other MI.
Abstract 319: Return of Spontaneous Circulation is Not Affected by Gastric Distension
Authors: Hanafusa Hiroaki , Naito Hiromichi , Ueda Yoshiyuki , Yumoto Tetsuya , Yorifuji Takashi , Weissman Alexandra , Rittenberger Jon C , Guyette Francis X , Fujishima Mamoru , Kobayashi Makoto , Morimoto Naoki , Nakao Atsunori
Published: July 2021

Introduction:
Gastric distension is a common complication after CPR and is caused by excess gastric inflation. Consequently, regurgitation of gastric contents and diaphragmatic eventration with increased intrathoracic pressure can occur, which may lead to anoxia and ventricular diastolic dysfunction. We measured gastric volume of out-of-hospital cardiac arrest (OHCA) patients using computed tomography (CT) scan images, and examined the effect of gastric distension on the return of spontaneous circulation (ROSC).

Hypothesis:
Gastric distension from over-inflation is associated with decreased incidence of ROSC.

Methods:
We conducted a retrospective observational study with OHCA patients transported to Tsuyama Chuo Hospital from 2014 - 2017. We included cases with total body CT scan examined after ROSC or death. We excluded inter-facility transport and insertion of gastric tube before CT. We measured the total gastric volume using 3D imaging software (FUJIN Anatomia, AZE, Tokyo). Primary outcome: Comparison of gastric volume between patients with and without ROSC. Secondary outcome: Factors associated with increased gastric volume. Mann Whitney U-test was used for the primary outcome. Multivariable regression analysis was used for the secondary outcome.

Results:
446 cases were included in the study. Median age was 79 [IQR: 68 - 86], 55% was male, 4% with initial rhythm VF/VT, 45% was estimated cardiac origin, 37% was witnessed arrest, 27% had ROSC. The total gastric volume was 400ml [192 - 793]. There was no difference in gastric volume between ROSC group and no-ROSC group (418 [232 - 733] vs 389 [183 - 824],
p
= 0.46). Airway management maneuver on arrival did not affect gastric volume (bag-valve-mask β: -99; 95% CI: -250 - 52, laryngeal tube β: -85; 95% CI: -228 - 59, endotracheal intubation: reference). Longer transport time was associated with increased the gastric volume (β: 5.6; 95% CI: 1.0 - 10) as was a non-cardiac origin of arrest (β: 121; 95% CI: 34 - 208).

Conclusion:
Abdominal distention was not associated with ROSC. Type of initial airway management did not significantly affect gastric volume. Factors associated with increased gastric volume at emergency department arrival were longer transportation time and non-cardiac origin of arrest.
Abstract 320: End-Tidal Carbon Dioxide Can Guide Fluid Resuscitation in a Cecal Ligation and Puncture Induced Rat Model of Sepsis
Authors: Xu Jing , Zheng Guanghui , Wu Liangliang , Fang Xiangshao , Wang Yue , Jiang Longyuan , Ling Qin , Yang Zhengfei , Tang Wanchun
Published: July 2021

Introduction:
Abnormal levels of end-tidal carbon dioxide (ETCO
2
) may reflect a derangement in perfusion, metabolism, or gas exchange. It is unclear if ETCO
2
can be used for fluid resuscitation (FR) compared with traditional mean arterial pressure (MAP) as an outcome predictor in sepsis.

Hypothesis:
Use of ETCO2 is better than MAP in guiding fluid resuscitation to improve lactate levels and microcirculatory blood flow in sepsis.

Methods:
Thirty-five male Sprague-Dawley rats weighing 350-400g were randomized to: 1) SHAM, n=5; 2) cecal ligation and puncture (CLP) Control group (with CLP, without FR, n=10); 3) ETCO
2
group (with CLP, FR began when ETCO
2
≤25 mmHg, n=10) and 4) MAP group (with CLP, FR began when MAP≤100 mmHg, n=10). Lactate level, cardiac output (CO), perfused small vessel density (PSVD) and sublingual microvascular flow index (MFI) was assessed at baseline, 2 h, 4 h, 8 h, 10 h and 12 h post-CLP. Survival duration was recorded.

Results:
After FR,CO in the ETCO
2
group increased compared with the MAP group 12h after CLP while lactate levels decreased compared with the Control and MAP groups (p<0.05) (Figure-1). Both sublingual PSVD and MFI decreased after CLP in the control group and MAP group but significantly improved in the ETCO
2
group 8h post-CLP. The average survival time in the ETCO
2
group was significantly greater than MAP group (Figure-2).

Conclusions:
ETCO
2
guided FR was associated with improved CO, lactate, microcirculatory flow, and survival time compared to MAP guided FR in a CLP-induced rat model of sepsis.
Abstract 322: Cyclooxygenase (COX) Inhibition Prior to CPR Decreases Heart Rate Variability in Pigs
Authors: Adams Jose A , Uryash Arkady , Lopez Jose R
Published: July 2021

Background:
Cyclooxygenase inhibitors (COX-1 and 2) are widely used and inhibit prostaglandin synthesis. COX inhibitors have been shown to increase overall cardiovascular risk. Heart rate variability (HRV) is a measure of the balance of autonomic nervous system and shown to be predictive of neurological outcome after cardiac arrest. Prostaglandins are cardioprotective and modulate HRV. We hypothesized that prostaglandin inhibition impacts short term CPR survival and outcomes based on HRV in swine.

Methods:
24 animals (30±5kg) were randomized to pretreatment with indomethacin (I) 2mg/kg (COX-1 Inhibitor), Celecoxib (C) 2mg/kg (COX-2 inhibitor) or placebo (P). VF was induced and after 3 minutes all animals received chest compression and ventilation. After 18 minutes of VF, vasopressin given and defibrillation attempted. Electrocardiogram, echocardiogram and hemodynamic measurements done at baseline (BL), after infusions (Tx) and return of spontaneous circulation (ROSC) at 30 and 180 minutes.

Results:
ROSC was achieved; 3/8 (I) compared with 7/8 (C), and 7/8 (P). No differences in blood gases or hemodynamics pre, during or post CPR between groups. Echo showed decrease function post resuscitation in surviving animals but not significantly different among groups. COX-2 inhibition induced a significant decrease in linear (SDNN, RMSSD) and frequency (HF) measures of HRV towards greater sympathetic tone, post resuscitation. Compared to P, COX-2 inhibition increased Troponin I levels at 180 min after ROSC; P [84(4)] vs C [721(31)] mg/dl (p< 0.001).

Conclusions:
COX-1 inhibition decreases ROSC, whereas COX-2 inhibition significantly increases indices of myocardial tissue damage, and decreases HRV. The impact on long term outcome is unknown. Since many adults use COX-1 or COX-2 inhibitors, studies analyzing post resuscitation outcomes of patients should consider the effects of prostaglandin synthesis inhibitors as confounding variables.
Abstract 325: Atheroprone Flow Enhances the Endothelial-to-Mesenchymal Transition
Authors: Baochang Lai , Zhao Li , Ming He , Lili Chen , Jiao Zhang , Shyy John Y-J
Published: July 2021

Introduciton and Hypothesis:
The endothelial-to-mesenchymal transition (EndoMT) is a pathophysiological process in the vascualture, manifested by the decreased expression of endothelial markers (vWF, CD31, and VE-cadherin) but increased mesenchymal genes (e.g., N-cadherin, FSP1, and vimentin). In light of the involvement of EndoMT in the pathogenesis of atherosclerosis, we hypothesize that atheroprotective pulasatile shear stress (PS) and atheroprone oscillatory shear stress (OS) have opposite effect in regulating the EndoMT genes in vascular endothelial cells (ECs).

Methods and Results:
RNA sequencing data from multi-timepoint shear stress experiments show that PS and OS had an opposite effect in regulating EndoMT genes in ECs. Further experimental validations with H
2
O
2
and gain- and loss-of-function approaches indicated that reactive oxygen species were involved in the OS-induced EndoMT, whereas AMP-activated protein kinase and sirtuin-1 could inhibit the OS-induced EndoMT. Compared with PS, OS increased the DNA methylation of the promoter region of
vWF
,
CD31
, and
CDH5
genes but decreased that of
CDH2
,
FSP1
, and
vimentin
genes.
In vivo
, EndoMT was evident in the partially ligated mouse carotid artery where flow pattern is disturbed. Furthermore, the anti-diabetic drug metformin and cholesterol-lowering drug atorvastatin suppressed EndoMT in ECs and in mouse aortae.

Conclusions:
Genome-wide analysis of mRNA expression profiles and conventional experimental validations revealed that atheroprotective and atheroprone flow had an opposite effect in regulating EndoMT. The translational implication of the current study builds on that metformin and atorvastatin had similar effects as atheroprotective flow in suppressing the EndoMT via AMPK and SIRT1 signaling in endothelium.
Abstract 329: N-acetylcyteine Alleviate Inflammasome-Induced Myocardial Pyroptosis After Successful Resuscitation in a Rat Model of Cardiac Arrest
Authors: He Fenglian
Published: July 2021

Introduction:
Previous studies have demonstrated that pyroptosis is involved in myocardial ischemia/reperfusion injury (MIRI). In addition, N-acetylcyteine (NAC) can attenuate inflammasome-induced pyroptosis during regional MIRI. In the present study, we investigated whether pyroptosis participate in global MIRI after successful resuscitation, and if it does, whether NAC can reduce inflammasome-induced pyroptosis in a rat model of cardiac arrest and resuscitation.

Hypothesis:
N-acetylcyteine reduces inflammasome-induced myocardial pyroptosis after successful resuscitation in a rat model of cardiac arrest.

Methods:
Fifteen male rats weighing 450g-550g were randomized into three groups: sham group, control group and NAC group (150 mg/kg). Ventricular fibrillation (VF) was electrically induced and untreated for 8 min. After VF, CPR was initiated for 8 mins and then defibrillation was attempted. Animals in sham group only were underwent the same operation but without inducing CA. The expressions of Nod-like receptor protein3 (NLRP3), adaptor apoptosis-associated speck-like protein (ASC), caspase-1 and gasdermin D (GSDMD) proteins were detected by western blotting at 6h following successful resuscitation.

Results:
All animals were resuscitated. Significantly higher levels expressions of GSDMD, NLRP3, ASC and caspase-1 were observed in control group and NAC group when compared with sham group. However, the expressions in GSDMD, NLRP3, ASC and caspase-1 were downregulated in NAC group in comparison with the control group. (Figure)

Conclusion:
N-acetylcyteine attenuate inflammasome-induced myocardial pyroptosis after successful resuscitation in a rat model of cardiac arrest. Figure Expressions of GSDMD, NLRP3, ASC and caspase-1 proteins, and effect of NAC on cardiac pyroptosis after successful resuscitation in a rat model of CA. (A) Representative western blotting images of GSDMD, NLRP3, ASC and caspase1 proteins in the hearts at 6h after successfully resuscitated (B) Quantitative protein analysis of GSDMD, NLRP3, ASC and caspase1 expression in three groups. The columns represent means ± SEM of three independent experiments. * p < .05
Abstract 331: Argon Promotes Vasorelaxation in Rat Pulmonary and Mesenteric Arteries
Authors: Shelton Elaine L , Berger Courtney D , Salzman Michele M , Balzer Claudius , Riess Matthias L
Published: July 2021

Introduction:
Despite cardiopulmonary resuscitation (CPR), more than 90% of patients having an out-of-hospital cardiac arrest in the US still die or endure severe neurological damage due to ischemia/reperfusion (IR) injury. Ventilation with Argon during CPR improves oxygenation, cardiac output, and survival in a porcine model of cardiac arrest. Similarly, inhalation of the volatile anesthetic, Sevoflurane, during CPR improves hemodynamic outcomes, but its usefulness is limited by its anesthetic effect and potential harm to providers and bystanders. In contrast, non-anesthetic noble gases like Argon can be safely administered outside of the hospital and may serve as a feasible adjuvant to mitigate IR injury following cardiac arrest. We hypothesize that Argon can decrease pulmonary and/or systemic vascular resistance, which may improve hemodynamic outcomes.

Methods:
Pressure myography assays were performed on isolated rat pulmonary and mesenteric arteries to determine the ability of Argon to promote vasodilation. Vessels were mounted in microvessel perfusion chambers and challenged with oxygenated Krebs buffer balanced with Argon (65%Argon:30%O
2
:5%CO
2
) or Nitrogen (65%N
2
:30%O
2
:5%CO
2
). Changes in intra-luminal diameter were recorded. Statistics: one-way ANOVA, p< 0.05.

Results:
Pulmonary arteries dilated in response to O
2
, while mesenteric arteries constricted. Argon exposure made pulmonary vessels significantly more sensitive to O
2
-induced dilation (mean Argon dilation = 133%, mean N
2
dilation = 99%). Conversely, argon blunted the ability of O
2
to constrict mesenteric arteries (argon mean constriction = 35%, nitrogen mean constriction = 41%).

Conclusion:
Our results indicate that Argon has vasodilatory effects in both the pulmonary and systemic circulations, making it a potentially useful therapeutic tool for mitigating IR injury following cardiac arrest or other instances of prolonged hypoperfusion. Future studies will address the mechanism underlying the ability of an inert noble gas to affect vasoactive signaling pathways.
Abstract 334: Cardioplegia Defibrillation of Circulatory Phase Ventricular Fibrillation in a Swine Model: Three Randomized Controlled Trials
Authors: Marill Keith A , Salcido David D , Sundermann Matthew L , Koller Allison C , Menegazzi James J
Published: July 2021

Introduction:
We previously found potassium cardioplegia followed by rapid calcium reversal (K plegia) can achieve defibrillation in a swine model of electrical phase ventricular fibrillation (VF) comparable to standard care.

Hypothesis:
Exploring 3 possible potassium (K) dose and timing protocols, we hypothesize K plegia may benefit resuscitation of circulatory phase VF.

Methods:
Three separate blinded randomized placebo-controlled trials were performed with electrically-induced VF untreated for durations of 6,9, and 12 minutes in a swine model. All experimental groups received infusion of 1 or 2 boluses of intravenous (IV) K followed by a single calcium reversal bolus. Only K was replaced by saline in the control groups. All other treatments were the same. Outcomes included: amplitude spectrum area (AMSA) during VF, resulting rhythms, number of defibrillations, return of spontaneous circulation (ROSC), and hemodynamics for 1 hour post ROSC. Single nominal and interval outcomes were compared with Fisher’s Exact test and Mann-Whitney U, respectively.

Results:
Twelve, 12, and 8 animals were included at 6, 9 , and 12 minute VF durations for a total of 32. ROSC, average number of shocks, and post-ROSC norepinephrine requirement are listed below. 4/6 K plegia and 2/6 control animals achieved ROSC in the 9 minute protocol, (p=0.24). Two of 8 animals that achieved ROSC with K plegia did so without electrical defibrillation.

Conclusions:
The majority of animals achieved ROSC after up to 9 minutes of untreated VF arrest using K plegia protocols. K plegia requires further optimization for both peripheral IV and intraosseous infusion, and to assess for superiority over standard care.
Abstract 335: Distinguishing Cardiac From Non-Cardiac Causes of Sudden Death: The Value of Novel Factors to Identify Risk of SCD
Authors: Allan Katherine S , Aves Theresa , Pinter Arnold , Morrison Laurie , Dorian Paul
Published: July 2021

Introduction:
Identifying those at risk for Sudden Cardiac Death (SCD) is imperative to prevent future events. There may be risk factors (RFs), triggers or warning symptoms preceding the SCD that could help identify those at greatest risk.

Methods:
This retrospective study included out-of-hospital cardiac arrests (OHCAs) of “no obvious cause” in the Greater Toronto Area, ages 2-45 from 2009-2012. Expert reviewers systematically adjudicated EMS, coroner, autopsy, toxicology and police reports to classify the etiology of arrest as SCD or SD due to non-cardiac etiologies (non-cardiac SDs). We compared past medical history, triggers and symptoms in the adjudicated SCD and non-cardiac SD groups and assessed their potential associations with SCD.

Results:
872 OHCAs were classified as SCDs (488; 56%) or non-cardiac SDs (384; 44%). The SCDs were mostly CAD (203; 41.6%), structural (155; 31.8%), congenital (8; 1.6%) and primary arrhythmic (76; 15.6%). The non-cardiac SDs were due to acute infection (67; 17.4%), metabolic (75, 19.5%), epilepsy (69, 18.0%), vascular (106; 27.6%) and respiratory (35, 9.1%). Cardiac RFs and exercise as a trigger were observed significantly more in SCDs vs. non-cardiac SDs (Table 1). Symptoms ≤24 hours prior were similar between groups except for chest pain and diaphoresis. After adjusting for patient and resuscitation variables, factors associated with increased risk of SCD were: increasing age (OR 1.03; 95%CI 1.01-1.05), male sex (OR 1.90; 95%CI 1.30-2.70), HTN (OR 1.80; 95%CI 1.11-3.10), smoking (1.60; 95%CI 1.02-2.60), public location (OR 2.10; 95%CI 1.13-3.80), exercise (OR 3.0 95%CI 1.56-5.59) and chest pain ≤24 hours prior (OR 2.90 95%CI 1.30-6.42).

Conclusion:
Many young SCDs have previously diagnosed cardiac RFs and acute symptoms suggestive of ischemia prior to their event. These findings highlight the potential value of better public awareness in the younger age group for signs and symptoms of ischemia and potential risk for SCD.
Abstract 337: Prognostic Impact of Cardiac Arrest Among Patients With ST-Elevation Myocardial Infarction
Authors: Kumar Anirudh , Huded Chetan P , Johnson Michael J , Menon Venu , Ellis Stephen G , Kapadia Samir R , Khot Umesh N
Published: July 2021

Background:
ST-elevation myocardial infarction (STEMI) is a potentially fatal condition that may be complicated by cardiac arrest (CA). However, the impact of CA complicating STEMI on prognosis in the contemporary era of rapid primary PCI is uncertain.

Methods:
We reviewed consecutive cases of STEMI treated with percutaneous coronary intervention (PCI) at our center between January 1, 2011 and December 31, 2016. Baseline clinical characteristics and in-hospital long-term outcomes were compared between patients with and without CA.

Results:
Among 1,272 patients with STEMI, 148 (11.6%) had CA (30.4% out-of-hospital, 69.6% after ED arrival). Compared to patients without CA, patients with STEMI+CA were more likely to have a history of heart failure, valve surgery, peripheral and cerebrovascular disease, and chronic kidney disease with a trend towards increased prevalence of left main or left anterior descending culprit vessel. Patients with STEMI+CA had greater creatinine (1.28±0.92 vs. 1.07±0.67, p=0.013, infarct size (CK-MB 171.6±131.6 vs. 139.2±117.0 ng/mL, p=0.010; troponin T 6.2±6.2 vs. 5.0±4.8 ng/mL, p=0.024), door-to-balloon-time (118.1±63.6 vs. 106.8±64.0, p=0.045), and incidence of cardiogenic shock (48.0% vs. 5.9%, p<0.0001) and intra-aortic balloon pump need (36.5% vs. 8.3%, p<0.0001). Patients with STEMI+ CA had higher rates of major bleeding (25.0% vs. 9.4%, p<0.0001) and post-PCI heart failure (13.5% vs. 8.1%, p=0.042). Patients with STEMI+CA had significantly greater mortality in-hospital (14.9% vs. 3.6%, p<0.0001) and at 1-year (22.9% vs. 9.3%, p<0.0001) (Figure).

Conclusions:
CA is a complication in >1 in 10 patients with STEMI and is associated with significantly higher morbidity and mortality compared with STEMI without CA. Strategies to improve the care and outcomes of STEMI patients with CA are needed.
Abstract 339: A Novel Continuous Heart Rate Variability Based Analytic to Predict Clinical Hemodynamic Instability Requiring Intervention
Authors: Belle Ashwin , Ward Kevin R , Benson Bryce , Salamango Mark , Islim Fadi
Published: July 2021

Background:
Sudden in-hospital hemodynamic instability (HI) due to cardiovascular and/or cardiorespiratory distress is a common occurrence. Causes can include hemorrhage, sepsis, pneumonia, heart failure, and others. Due to the body’s compensatory mechanisms, heart and respiratory rate, and blood pressure can be late indicators of HI. When detected late or left unrecognized HI can lead to complications and even death. Heart rate variability (HRV) has been demonstrated to reflect the status of the autonomic nervous system with changes in HRV linked to HI. However, to date, HRV has not demonstrated sufficient accuracies in adults to warrant widespread adoption. We have developed a novel nonlinear single lead ECG HRV analytic based on signal processing and machine learning features specific to HI physiology.

Objective:
Validate the capability, accuracy, and lead times of the HRV analytic to predict HI in hospitalized patients who were subjects of Rapid Response Team (RRT) activations.

Methods:
We retrospectively analyzed 4483 hours of ECG data from 22 RRT patient cases (16 male, 6 female) using the previously developed HRV analytic. A multi-clinician review adjudicated the occurrence of HI and need for intervention. The prediction lead time prior to the RRT call was calculated for these cases.

Results:
Of the 22 RRT cases, 13 calls were due to HI requiring a range of life-saving interventions, and 9 RRT cases for reasons not associated with HI and requiring no life-saving interventions. The analytic correctly distinguished between HI vs. non-HI RRT calls with 100% accuracy thus displaying 100% positive and negative predictive values. In the HI cases, the analytic detected HI with a median lead time of 7.7 hours prior to the RRT call with a range of 14 minutes to 38.4 hours.

Conclusion:
In this RRT cohort, a novel HRV analytic developed through machine learning based on HI physiology demonstrated its potential to forecast HI well before vital signs and other factors led to RRT activation resulting in life-saving interventions. These substantial lead times, as well as the ability to distinguish HI from non-HI RRT calls, may lead to the ability to reduce HI and improve outcomes while reducing unnecessary RRT activations.
Abstract 344: The Association Between ALS Response Interval and Out-of Hospital Cardiac Arrest Outcomes
Authors: Grunau Brian , Kawano Takahisa , Tallon John , Scheuermeyer Frank , Reynolds Joshua , Besserer Floyd , Barbic David , Brooks Steven , Straight Ron , Christenson Jim
Published: July 2021

Objective:
There is conflicting data in studies investigating the effectiveness of advanced life support (ALS) for out-of-hospital cardiac arrest (OHCA). Within a tiered BLS-ALS system, we sought to determine if the ALS response interval was associated with patient outcomes.

Methods:
This secondary analysis examined prospectively identified consecutive non-traumatic adult OHCAs from 2006-2016 in British Columbia. We excluded EMS-witnessed arrests and those not treated by ALS. The primary and secondary outcomes were survival and favorable neurological outcomes (mRS ≤3) at hospital discharge. Using logistic regression we estimated the association of ALS response interval (9-1-1 call to ALS arrival) and outcomes, adjusting for treatment year, response interval of the first EMS unit, and other baseline characteristics. We drew spline curves to illustrate this relationship.

Results:
Of 12,722 included cases, survival was 12%. The median response interval for the first EMS unit was 6.4 minutes (IQR 5.2 - 8.3) and for ALS was 11.8 minutes (IQR 8.7 - 16.5).The adjusted odds of survival and favourable neurological outcome for each additional minute in ALS response interval were 0.98 (95 % CI 0.96-0.99) and 0.98, (95% CI 0.97-0.99) respectively. The spline curve demonstrated an initial decline in survival probability that moderated at approximately 11 minutes.

Conclusion:
Among ALS-treated subjects within our tiered EMS system, earlier ALS arrival was associated with improved survival and favorable neurological outcomes. The greatest yield of ALS care may be prior to 11 minutes. This may help inform the optimal deployment configuration of prehospital providers.
Abstract 347: End-Stage Renal Disease (ESRD) Patients Undergoing Hemodialysis Have Higher Possibility of Return of Spontaneous Circulation (ROSC) During Out-Hospital Cardiac Arrest (OHCA) and Non-Inferior Short-Term Survival: A Nationwide Population Cohort Study in Taiwan
Authors: Hsieh Ming-Shun , How Chorng-Kuang , Chen Pau-Chung
Published: July 2021

Objective:
To compare the incidence rate of return of spontaneous circulation (ROSC) between end-stage renal disease (ESRD) patients undergoing hemodialysis and non-ESRD patients after out-hospital cardiac arrest (OHCA) and subsequent hospital outcomes.

Participants and Methods:
We enrolled a cohort of 101,876 ESRD patients undergoing hemodialysis between 2000 and 2010 years. After matching for age and gender, an equal number of non-ESRD patients were enrolled to serve as the comparison cohort. We compared the incidence rate of OHCA and subsequent ROSC between the two cohorts. Hazard ratios (HRs) with 95% confidence interval (CI) of OHCA incidence rate were calculated using the Cox proportional hazards regression model. Chi-square test was conducted to compare the incidence rate of ROSC between the two cohorts. Multi-variate analysis with logistic regression was conducted to calculate the odds ratio (OR) of ROSC for different variables. Kaplan-Meier analysis with log-rank test was conducted to determine the difference of survival rate after ROSC between the two cohorts.

Results:
During the median follow-up of 3.71 and 5.65 years for ESRD and non-ESRD patients, there were 2563 (2.51%) and 1125 (1.10%) OHCA events, respectively. The condition of ESRD undergoing hemodialysis presented as an risk factor to develop OHCA compared with non-ESRD patients (adjusted HR = 2.11, 95% CI 1.89-2.36,
P
<0.0001 ). Within these OHCA patients with ESRD and non-ESRD, 1085 of 2563 (42.33%) and 202 of 1125 (17.96%) patients got ROSC. In the multivariate analysis with logistic regression, ESRD under hemodialysis presented to be a protective factor for ROSC (adjusted OR = 2.47, 95% CI 1.90-3.21,
P
<0.0001). In the further Kaplain-Meier analysis with log-rank test, the ESRD patients with OHCA and subsequent ROSC had a better 30-day hospital survival rate compared with the non-ESRD patients.

Conclusion:
Although, ESRD patients undergoing hemodialysis had a higher incidence rate of OHCA compared with non-ESRD patients. They had a higher possibility to get ROSC and had a better short-term hospital outcome. This observation may be explained by the training of vascular compliance during regular hemodialysis.
Abstract 349: Prognostication for Out-of-Hospital Cardiogenic Cardiac Arrest Patients Using Advanced Machine Learning Technique
Authors: Seki Tomohisa , Tamura Tomoyoshi , Suzuki Masaru
Published: July 2021

Introduction and Objective:
Early prognostication for cardiogenic out-of-hospital cardiac arrest (OHCA) patients remain challenging. Recently, advanced machine learning techniques have been employed for clinical diagnosis and prognostication for various conditions. Therefore, in this study, we attempted to establish a prognostication model for cardiogenic OHCA using an advanced machine learning technique.

Methods and Results:
Data of a prospective multi-center cohort study of OHCA patients transported by an ambulance to 67 medical institutions in Kanto area of Japan between January 2012 and March 2013 was used in this study. Data for cardiogenic OHCA patients aged ≥18 years were retrieved and patients were grouped according to the time of calls for ambulances (training set: between January 1, 2012 and December 12, 2012; test set: between January 1, 2013 and March 31, 2013). From among 421 variables observed during the period between calls for ambulances and initial in-hospital treatments of cardiogenic OHCA, 38 prehospital factors or 56 prehospital factors and initial in-hospital factors were used for prognostication, respectively. Prognostication models for 1-year survival were established with random forest method, an advanced machine learning method that aggregates a series of decision trees for classification and regression. After 10-fold internal cross validation in the training set, prognostication models were validated using test set. Area under the receiver operating characteristics curve (AUC) was used to evaluate the prediction performance of models. Prognostication models trained with 38 variables or 56 variables for 1-year survival showed AUC values of 0.93±0.01 and 0.95±0.01, respectively.

Conclusions:
Prognostication models trained with advanced machine learning technique showed favorable prediction capability for 1-year survival of cardiogenic OHCA. These results indicate that an advanced machine learning technique can be applicable to establish early prognostication model for cardiogenic OHCA.
Abstract 350: Construction and Validation of a New Termination-of-Resuscitation Rule for Out-of-Hospital Cardiac Arrest in the Japanese Population; JCS-ReSS Study
Authors: Hashiba Katsutaka , Tahara Yoshio , Kimura Kazuo , Endo Tsutomu , Tamura Kouichi , Yonemoto Naohiro , Nonogi Hiroshi , Shimokawa Hiroaki , Nagao Ken
Published: July 2021

Background:
Termination of resuscitation (TOR) rules for OHCA have been constructed for better utilization of hospital healthcare resources and increasing the availability of care for other patients. However, TOR rules in the prehospital settings are not legally implemented in Japan. Thus, almost all OHCA patients are transported to the hospital, regardless to the possibility of successful resuscitation.

Objective:
To validate the TOR-ALS rule in Japan and to establish a new TOR rule for terminating ongoing resuscitation just after hospital arrival.

Methods:
Data from a nationwide database of a prospective population-based cohort using an Utstein-style template for OHCA patients during January 2011 to December 2015 was used for the current analysis. We constructed a new TOR rule consisting of 5 factors (no-witness, no-return of spontaneous circulation (ROSC), asystole for the initial rhythm, no-defibrillation before hospital arrival, age>75) including the patients during 2011 to 2013 (derivation cohort). Statistical values to predict death and unfavorable neurological outcome(UNO) at one-month were calculated for the TOR-ALS rule (no-witness, no-bystander CPR, no-ROSC, no-defibrillation) and the new rule, respectively. After constructing the new rule, we validated it in a cohort of patients during 2014 to 2015 (validation cohort).

Results:
Of the 629,471 patients documented for the study period, 466,033 adult patients with OHCA without external causes of arrest were included in the present analysis. In the derivation cohort, values (PPV/NPV/sensitivity/specificity/AUC-ROC) to predict death for each rule were; TOR-ALS rule (99.35%/6.01%/29.89%/95.87%/0.63), new rule (99.61%/6.53%/34.96%/97.05%/0.66). Values to predict UNO were, TOR-ALS rule (99.90%/3.09%/29.37%/98.75%/0.64), new rule (99.97%/3.34%/34.28%/99.49%/0.67). In the validation cohort, values to predict death were, TOR-ALS rule (99.38%/6.53%/26.97%/96.81%/0.62), new rule (99.66%/7.24%/34.00%/97.79%/0.66). Values to predict UNO were, TOR-ALS rule (99.13%/3.36%/26.43%/99.11%/0.63), new rule (99.98%/3.71%/33.24%/99.75%/0.67).

Conclusion:
The new TOR rule has a higher PPV and specificity to predict unfavorable outcome of OHCA in a Japanese population.
Abstract 355: Performance of Inclusion and Exclusion Criteria Based on Prognosis in an Interventional Out-of-Hospital Cardiac Arrest Study
Authors: Krehel Nick , Callaway Clifton W , Doshi Ankur , Elmer Jonathan , Guyette Francis X , Okubo Masashi , Weissman Alexandra , Rittenberger Jon C , Dezfulian Cameron
Published: July 2021

Introduction:
Selection of out-of-hospital cardiac arrest (OHCA) patients for inclusion in randomized control trials (RCT) presents a challenge. The goal is to enroll patients with severe injury warranting intervention yet exclude those with extreme irreversible disease. Selection early after return of spontaneous circulation (ROSC) is complicated by a relative paucity of prognostic variables. We examined the accuracy of enrollment criteria in the iNO OHCA study (NCT03079102) in excluding patients likely to have good or poor outcomes within three hours (3h) of ROSC.

Methods:
OHCA patients arriving to two tertiary care centers in Pittsburgh were screened within 3h of ROSC. We excluded subjects that followed commands (good prognosis expected) and subjects expected to have poor prognosis based on: Full Outline of UnResponsiveness Brainstem (FOUR B) score <2; CPR time >40 min; investigator estimate of >95% mortality; CT evidence of cerebral edema or intracranial hemorrhage; clinical evidence of myoclonic status epilepticus; or traumatic OHCA etiology. We also excluded subjects not within 3h of ROSC. We compared discharge survival and good neurologic outcome based on disposition (location).

Results:
Over a nine-month period we screened 155 patients with ROSC following OHCA, 20 subjects (13%) were included in the study and 135 (87%) were excluded (
Table
). The odds ratio (OR) of survival if excluded for poor prognosis was 0.03 (95% CI: 0.01 - 0.08) and worsened when >1 criteria were met. Exclusion for good prognosis was associated with improved survival (OR = 67.2 [95% CI: 14.3 - 316.3]).

Conclusions:
Our criteria reliably exclude OHCA subjects with good or poor prognosis within 3h of ROSC, yielding a study population with intermediate survival which can be applicable to future OHCA trials. Our criteria selected a minority (13%) of OHCA patients likely to benefit from intervention while reserving resources.
Abstract 357: Resuscitative Balloon Occlusion of the Aorta in Non-Traumatic out of Hospital Cardiac Arrest - Evaluation of an Educational Program
Authors: Brede Jostein Rødseth , Lafrenz Thomas , Kruger Andreas Jørstad , Søvik Edmund , Steffensen Torjus , Kriesi Carlo , Steinert Martin , Klepstad Pål
Published: July 2021

Background:
Out of hospital cardiac arrest (OHCA) is a critical incident with a high mortality rate. Augmentation of the circulation and hence oxygen delivery to vital organs such as the brain and heart during cardio-pulmonal resuscitation (CPR) might be beneficial. Use of resuscitative endovascular balloon occlusion of the aorta (REBOA) redistribute cardiac output to the organs proximal to the occlusion. Preclinical data supports that patients in non-traumatic CA might benefit from REBOA placed in the thoracic level during CPR.

Methods:
We developed a REBOA team-based training program involving the physicians and prehospital emergency medical service (P-EMS) operators working on the National Air Ambulance helicopter base in Trondheim, Norway. The program consists of a four-step approach to educate, train and implement the REBOA procedure in a simulated prehospital setting. An objective structured assessment of prehospital REBOA application (OSAPRA) scoring chart and a special designed training dummy was made for this study.

Results:
7 physicians and 3 P-EMS operators participated. The time needed to perform the REBOA procedure was 8,5 min (range; 6,3 - 12,7). The corresponding time from arrival at scene to balloon inflation was 12,0 min (range; 8,8 - 15). The total objective assessment scores of the candidates’ competency was 41,8 points out of 48 (range; 39 - 43,5). The advanced cardiovascular life support (ACLS) remained at standard quality, regardless of the simultaneous REBOA procedure.

Conclusions:
This four-step approach to educate, train and implement the REBOA technique to a prehospital working team is feasible and provides adequate competence. In a simulated setting the procedure does not add significant time to the prehospital resuscitation time nor does the procedure interfere with the quality of the ACLS.
Abstract 359: Use of Resuscitative Balloon Occlusion of the Aorta in a Swine Model of Prolonged Cardiac Arrest
Authors: Tiba Mohamad H , McCracken Brendan M , Cummings Brandon C , Colmenero Carmen I , Rygalski Chandler J , Hsu Cindy H , Sanderson Thomas H , Nallamothu Brahmajee K , Neumar Robert W , Ward Kevin R
Published: July 2021

Introduction:
Despite advancements in CPR, survival to hospital discharge remains low for in- and out-of-hospital cardiac arrest (CA). Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) is an evolving tool for temporary control of non-compressible truncal hemorrhage. In this investigation, we examined whether REBOA use during non-traumatic CA would produce favorable hemodynamic changes associated with return of spontaneous circulation (ROSC).

Hypothesis:
We hypothesized that REBOA use during CPR would result in higher coronary perfusion pressure (CPP) and common carotid artery blood flow (C-Flow) in a prolonged model of CA.

Methods:
Six male swine were anesthetized and instrumented to measure and monitor CPP, and C-Flow. A REBOA catheter (Prytime Medical Devices) was advanced into zone 1 of the aorta through the femoral artery. Ventricular fibrillation was electrically induced and untreated for 8 minutes. CPR was started manually at minute-8, then changed to mechanical CPR at minute-12 for the duration of the experiment. Continuous infusion of epinephrine (0.0024mg/kg/min) was simultaneously started with mechanical CPR. The REBOA balloon was inflated beginning at minute-16 for 3 minutes then deflated for 3 minutes for a total of 6 cycles. At the end of the final cycle (REBOA inflation), CPR was stopped (after 33 minutes of total arrest time) and animals were defibrillated using 200 J biphasic shocks, repeated up to 6 times. Animals achieving ROSC were monitored for an additional 25 minutes.

Results:
Analysis using repeated measure ANOVA showed significant differences between balloon deflation and inflation periods for CPP (p<0.0001) with mean difference(SD) of 14(2.6) (Range: 17 to 42) mmHg and for C-Flow (p<0.0001) with mean difference(SD) 16(23) (Range: 115 to 269) mL/min across all animals. Three animals achieved ROSC and had significantly higher CPP (48 vs. 24mmHg, p<0.0001) and C-Flow (249 vs. 168mL/min) by t-test (p<0.0001). Post-mortem aortic histology did not reveal any changes produced by balloon inflation.

Conclusion:
REBOA significantly increased CPP and C-Flow in this swine model of prolonged CA. These increases may have contributed to the ability to achieve ROSC after greater than 30 min of CA.
Abstract 361: Improving Hemodynamics During Cardiopulmonary Resuscitation With Occlusion of the Abdominal Aorta
Authors: Allen Jason , Ripeckyj Adrian , Shekar Kadambari , Yannopoulos Demetri , Bartos Jason
Published: July 2021

Background:
There are approximately 400,000 out of hospital cardiac arrests in the United States each year. Effective CPR delivers approximate 30% of normal blood flow to the heart and 40% of normal blood flow to the brain. Cardiac and neurological recovery after a cardiac arrest remains a challenge in this population. We hypothesized that inflating a balloon in the abdominal aorta would preferentially shunt cardiac output to the brain and heart during CPR and improve hemodynamics thereby potentially reducing the injury incurred during prolonged CPR, similar to the rationale behind the use of the endovascular balloon occlusion that has been used in trauma.

Methods:
To assess our hypothesis, we used a porcine model of prolonged CPR. Each animal was anesthetized and placed on hemodynamic monitoring devices. Following hemodynamic measurements at baseline, VF was induced. After five minutes of VF, CPR was initiated. After ten minutes of CPR representing bystander CPR, we then placed a balloon in the abdominal aorta via the femoral artery. Flow to the abdominal aorta was halted with inflation of the balloon and occlusion of the aorta. CPR was continued for a total of 45 min with epinephrine delivery every 5 minutes after balloon inflation consistent with standard ACLS. For our experimental group we had a total of ten animals, which were compared to 17 control animals that underwent the same protocol except for balloon placement.

Results:
The results of our study demonstrate a statistically significant increase in thoracic systolic aortic blood pressure with balloon inflation (78.2 mmHg in animals with the balloon inflated and 64.3 mmHg in controls, p < 0.05). The diastolic aortic blood pressure was similar between groups. As a result of the hemodynamic changes associated with balloon inflation, coronary perfusion pressures also statistically increased (24.9 mmHg in animals with the balloon inflated compared to 17.5 mmHg in the control animals, p < 0.05).

Conclusion:
The findings of our study suggest there are potentially hemodynamic benefits to coronary perfusion and likely cerebral perfusion as a result of an intra-abdominal balloon occlusion which may reduce the injury to the organs critical to successful functional recovery after prolonged cardiac arrest.