bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 19558: An Increase in Visceral Adipose Tissue Attenuation After a One-Year Lifestyle Intervention in Men with Features of the Metabolic Syndrome is Related to Improvements in Lipid Profile Independent of the Reduction in Visceral Adiposity
Authors: Nazare Julie-Anne , Smith Jessica , Borel Anne-Laure , Lemieux Isabelle , Alméras Natalie , Bergeron Jean , Tremblay Angelo , Poirier Paul , Després Jean-Pierre
Published: April 2024

Background:
On the basis of its specific attenuation range (expressed in Hounsfields units, HU), visceral adipose tissue (VAT) can be identified and quantified by computed tomography (CT). In addition, cross-sectional studies have suggested that mean VAT attenuation in HU could reflect variation in VAT density. Objectives: The present study examined: 1) the effect of a one year lifestyle modification program on VAT attenuation in a sample of abdominally obese subjects with features of the metabolic syndrome, 2) whether changes in VAT attenuation were independently associated with improvements in the cardiometabolic risk (CMR) profile, beyond the reduction in VAT area.

Methods:
From the 144 subjects initially recruited, 109 men with features of the metabolic syndrome (age: 48±9 y, waist circumference: 108±9 cm, triglycerides: 2.46±0.92 mmol/L) who had an abdominal CT scan at the L4-L5 level at both baseline and after one year of lifestyle intervention were included in the present analyses. VAT area and VAT attenuation were assessed as well as a comprehensive CMR profile.

Results:
After one year of the lifestyle intervention, VAT attenuation significantly increased (+5.6 ± 3.9 HU, p<0.0001). One-year changes in VAT attenuation were significantly correlated with changes in VAT area (r=-0.62, p<0.0001), triglycerides (r=-0.40, p<0.0001), HDL cholesterol (r=0.35, p=0.0002), apolipoprotein B (r=-0.42, p<0.0001) and HOMA-IR (r=-0.24, p=0.01). Multiple regression analyses including changes in both VAT attenuation and VAT area showed that only VAT attenuation was an independent correlate of changes in triglycerides, HDL cholesterol and apolipoprotein B, whereas VAT area alone explained the variance in changes in HOMA-IR.

Conclusion:
The increase in VAT attenuation after one year of lifestyle intervention is independently associated with improvements in lipid profile, beyond the reduction in visceral adiposity.
Abstract 19576: Identification of a Novel Signaling Pathway for S1P Mediated Cardioprotection
Authors: Xiang Sunny Y , Ouyang Kunfu , Smrcka Alan V , Chen Ju , Heller Brown Joan
Published: April 2024

Background

—
Recently, we demonstrated that activation of the small GTPase RhoA in cardiomyocytes induces striking protection against ischemia/reperfusion (I/R) injury. The GPCR agonist, sphingosine 1-phosphate (S1P), well known for its profound protective effects on I/R injury, activates RhoA. Here we asked whether S1P protects cardiomyocytes through RhoA signaling and further characterized the mechanism and downstream targets responsible.

Methods and Results

—
We determined that stimulation of the isolated perfused mouse heart with S1P activates RhoA and protein kinase D (PKD). Phospholipase Cε (PLCε) is a newly identified RhoA target. Genetic deletion of PLCε fully abolishes PKD activation by S1P and blocks S1P mediated protection from I/R injury. Cardioprotection by S1P is also abolished in PKD1
-/-
(KO) mice. We used the neonatal rat ventricular myocytes (NRVMs) model to confirm these findings and further elucidate molecular mechanisms. S1P elicits robust activation of PKD in NRVMs through effects on RhoA (blocked with C3) and PLCε (blocked with siRNA). PKD is required for S1P mediated protection against H
2
O
2
induced cell death implicating PKD as a pro-survival target of S1P/RhoA/PLCε signaling. We further identified the PKD substrate Slingshot 1L (SSH1L) as an S1P target that is regulated through PKD mediated phosphorylation. Importantly, regulation of SSH1L by S1P reduces translocation of Cofilin2, an SSH1L substrate, to the mitochondrion in response to H
2
O
2
. In addition, we demonstrate that Cofilin2 co-IPs with the pro-death protein Bax and that mitochondrial translocation of Bax is inhibited through this pathway by S1P. Finally, we demonstrate that S1P significantly reduces translocation of Cofilin2 and Bax to mitochondria, in parallel with its ability to protect the isolated heart against I/R injury.

Conclusion

—
These studies reveal previously unknown mechanisms through which GPCR agonists that activate RhoA induces cardioprotection. In addition they define multiple new molecular players (PLCε, PKD, SSH1L and Cofilin2) that converge at the level of the mitochondrion to protect cardiomyocytes from oxidative stress.
Abstract 19585: Tidal Volume and Minute Ventilation Measurement at High, Low, and Erratic Respiratory Rates by a Non-Invasive Respiratory Monitoring System
Authors: Voscopoulos Christopher , Fahy Darren , Brayanov Jordan , Lalli Michael , Yocum Nicole , Freeman Jenny
Published: April 2024

Introduction:
Changes in minute ventilation (MV) & tidal volume (TV) signal the beginning of respiratory compromise which often precedes cardiopulmonary arrest. Currently, respiratory monitoring in non-intubated patients lacks objective & quantitative methodology for determining the adequacy of ventilation. A non-invasive, Respiratory Volume Measurement (RVM) system has been developed to measure MV, TV and respiratory rate (RR) continuously. Previous work has demonstrated clinically acceptable accuracy and precision of RVM monitoring across normal respiratory patterns and rates. Hypothesis: RVM monitoring accurately yields tidal volume & minute ventilation across abnormal breathing rates, and erratic patterns.

Methods:
We studied 51 adult subjects (93 visits, 2252 tests) at low (4 - 6 bpm), normal (8 - 20 bpm), and high (30 - 40 bpm) respiratory rates and during erratic breathing. TV, RR and MV were measured simultaneously with an impedance-based RVM system (ExSpiron, Respiratory Motion, Inc., Waltham, MA) and a dry rolling seal spirometer (Morgan Scientific Inc., Haverhill, MA). Advanced data processing algorithms displayed a real time respiratory curve and calculated RVM measurements.

Results:
Throughout the range of 4 bpm to 40 bpm and during erratic breathing, RVM measurements are highly-correlated with spirometer measurements, with an average MV and TV correlation coefficient of 0.96, 95% CI 0.93 to 0.99 (Fig 1). Across all subjects, median correlation coefficients ranged from 0.91 to 0.99.

Conclusions:
High correlation (r = 0.96) between spirometric measurements and RVM signals concludes that the RVM system is capable of monitoring respiratory status during normal and erratic breathing, and at high and low breathing rates. As a passive, continuous, non-invasive system, RVM monitoring of non-intubated patients could provide earlier indications of respiratory decline potentially permitting interventions to prevent cardiopulmonary arrest.
Abstract 19631: MicroRNAs Modulation in a Mice Model of Physiological Left Ventricular Hypertrophy
Authors: Martinelli Nidiane C , Cohen Carolina R , Schneider Stefanie , Schneider Stefanie , Dos Santos Katia , Andrades Michael E , Clausell Nadine , Biolo Andreia , Rohde Luis E
Published: April 2024

INTRODUCTION: Physiological left ventricular hypertrophy (LVH) has distinct phenotypic adaptations that might me modulated by microRNAs (miRs) which are fine-tune regulators of gene expression. We tested the hypothesis that physiological LVH has differential miRs expression in mice subjected to a voluntary exercise protocol.

METHODS: Balb/c mice were kept in cages with exercising wheels (Exercise group - EXE; n=15 sacrificed on day 7 and n=17 sacrificed 35 days after training) or in cages without wheels (Sedentary group - SED; n=12 in each time point). LVH was evaluated by the left ventricular weight/body weight ratio (LVW/BW). MiRs were extracted with miRNeasy kit (Qiagen, USA). A microRNA microarray based on the miRBase version 16 (LC Sciences, Houston, Texas, EUA) was carried out using a pool of miRs extracted from the LV. After miR extraction, 50 pM of synthetic cel-miR-39 were spiked-in as a standard control. RT-qPCR was performed with microRNA Reverse Transcription Kit® and TaqMan Probes® (Applied Biosystems Inc., USA).

RESULTS: After 7 days of training there was an increase of 7% in LVW/BW ratio on EXE compared to SED group (3.6±0.2 vs. 3.3±0.1, respectively; p=0.004) and this result was sustained at 35 days (12% increase; 3.7±0.2 vs. 3.3±0.1, respectively; p<0.001). 7 DAYS analyses: expression of miR-26b and miR-143 was decreased in the EXE compared to the SED group (0.5-fold, p=0.017 and 0.7-fold, p=0.018, respectively). miR-150 showed an increased expression in the EXE group (3.0-fold, p=0.001). 35 DAYS analyses: expression of miR-27a was down-regulated (0.8-fold, p=0.03), while miR-150 was up-regulated (1.9-fold, p=0.016) in the EXE group. miRs previously described to be involved in cardiovascular diseases (miR-21, miR-195 and miR-499) were similar between groups.

CONCLUSIONS: Our data suggest that physiological LVH was associated to significant modulation of miRs that might regulate affect metabolic adaptations (miR-26b:GSK3B) and apoptosis pathway activation (miR-150:FOXO4). Also miRs could have an effect on cellular growth and hypertrophy (miR-27a:IGF1 and miR-143:MTPN).
Abstract 19661: Integrin Imaging for the Detection of Diffuse Myocardial Fibrosis in Patients with Hypertrophic Cardiomyopathy: Direct Comparison Between Single-Photon Emission Computer Tomography and Cardiovascular Magnetic Resonance The SCAR Study
Authors: Cocker Myra S , Dwivedi Girish , Marvin Brian , Poirier Marlie , Dennie Carole , Wells Glenn , Ascah Kathy , Roberts Robert , Dick Alexander , Ruddy Terry D
Published: April 2024

Background
Hypertrophic cardiomyopathy (HCM) promotes diffuse myocardial collagen synthesis, disarray and hypertrophy. Cardiovascular magnetic resonance (CMR) imaging using late gadolinium enhancement (LGE) can detect focal fibrosis in HCM, although the injury process in HCM may be global and diffuse. αvβ3 is a vitronectin integrin receptor associated with fibroblasts and collagen synthesis. A
99
Technetium compound (
99m
Tc-
NC100692
) that binds with high affinity to αvβ3 has been developed. Thus, we hypothesize that
99m
Tc-
NC100692
could be used to detect focal and diffuse myocardial fibrosis in patients with HCM.

Methods
5 patients (62±11 years, 4 male) with a diagnosis of HCM from echocardiography were prospectively recruited. Patients underwent SPECT
99m
Tc-
NC100692
and CMR LGE imaging. Using a 17-segment model,
99m
Tc-
NC100692
images were visually assessed for myocardial uptake using a 3-point scale. LGE images were assessed for the presence or absence of enhancement per segment.

Results
For the 5 patients, 85 segments were evaluated and all had some degree of
99m
Tc-
NC100692
uptake. Three patients had evidence for focal LGE in 9 segments. Of these 9 segments, 5 had matched high-grade
99m
Tc-
NC100692
uptake. One patient had strong apical
99m
Tc-
NC100692
uptake without any evidence of hypertrophy nor LGE. The remaining 79 segments had low-grade
99m
Tc-
NC100692
uptake with lack of evidence for LGE.

Conclusion
Diffuse low-grade myocardial uptake of
99m
Tc-
NC100692
in patients with HCM may be suggestive of diffuse fibrosis.
99m
Tc-NC10069 may serve as a marker of myocellular disarray although further studies are required to determine the specificity of
99m
Tc-NC100692.
Abstract 19674: Late Endothelial Progenitor Cells (EPCs) and Platelets Interact through Endothelial Differentiation Gene (Edg)-2-Lysophosphatidic Acid (LPA) Axis under the Regulation of Peroxisome Proliferator-Activated Receptor (PPAR)-δ, Leading to Vasculogenesis
Authors: Han Jung-Kyu , Ahn Hyo-Sook , Won Joo-Yun , Kang Jee-Hoon , Yang Han-Mo , Cho Hyun-Jai , Park Kyung-Woo , Kang Hyun-Jae , Oh Byung-Hee , Park Young-Bae , Kim Hyo-Soo
Published: April 2024

Background PPAR-δ has been implicated in various cellular metabolism, but the roles in vascular biology are largely unexplored. Here, we investigated the effects of PPAR-δ activation on late EPC-platelet network.

Methods & Results
GW501516
(500nM), a highly selective PPAR-δ agonist treatment enhanced BrdU incorporation to human late EPCs, and augmented their pro-vasculogenic effects such as Matrigel tube formation and scratch-wound healing dose-dependently. To reveal the mechanism, the expression level of Edg family members was screened in late EPCs after PPAR-δ activation. We found that only Edg-2 mRNA and protein expression, which is a major receptor for LPA, were specifically upregulated by GW501516. ChIP and promoter assays demonstrated the direct transcriptional regulation of Edg-2. Edg-2 is a membrane receptor for LPA which is the major lysophospholipid growth factor generated on platelet activation.
GW501516
(500nM), the supernatant of activated platelets, or LPA (100nM) induced the proliferation (BrdU incorporation) of late EPCs, and enhanced their provasculogenic functions such as chemotaxis (Transwell), planar migration (scratch wound healing), and capillary tube formation (in vitro Matrigel). Co-treatment of
GW501516
and the supernatant synergistically enhanced the above results, suggesting the interaction between late EPCs and platelets augmented by PPAR-δ activation. But GSK0660 (1μM, PPAR-δ antagonist) or Ki16425 (3μM, EDG-2 blocker) treatment reversed the results. In vivo Matrigel plug assay (n=4, each group), the combination of late EPCs (106/plug) and platelets robustly induced capillary formation, compared with late EPCs or platelets alone.
GW501516
potentiated the interaction, leading to more capillaries. In vivo mouse skin wound model (n=4, each group), late EPCs in platelet gel enhanced the wound healing with new vessel formation, which was augmented by
GW501516
, confirming the interaction in vivo. PPAR-δ or EDG-2 siRNA transfection blocked all the in vivo effects of GW501516.

Conclusions Platelets and late EPCs play a key role in vascular regeneration via Edg-2 - LPA axis. PPAR-δ augments the interaction through Edg-2 upregulation, suggesting its agonist as a good therapeutic tool for vascular regeneration.
Abstract 19700: MRI Based Non-Invasive Detection of Cardiomyocyte Hypertrophy and Cell Volume Changes
Authors: Coelho-Filho Otavio , Shah Ravi , Mitchell Richard , Moreno Hector , Kwong Raymond , Jerosch-Herold Michael
Published: April 2024

BACKGROUND:
Cardiac hypertrophy results from cardiomyocyte cell hypertrophy and expansion of the extracellular matrix. To elucidate the tissue phenotype requires a combined assessment of these characteristics. The goal of this study was to validate a novel MRI-based approach for the combined assessment of extra-cellular matrix expansion and cell size.

METHODS:
Hypertension was induced by L-NAME (3mg/ml) in 17 wild-type mice (body-weight=37.2±2.3g). 13 mice (body-weight=37.5±2.5g) received placebo. Transaortic constriction (TAC) was performed in 11 male-wild-type (body-weight=25.2±2.0 g) mice. Mice were imaged at baseline, 7-weeks after L-NAME treatment, and 2 weeks after TAC at ≥4.7T. T1 was quantified with a Look-Locker cine technique, pre and post gadolinium. The intra-cellular lifetime of water (τic), a-cell size dependent parameter, and the extracellular volume fraction (ECV) were determined by fitting R1 in tissue, against R1 in the blood pool, with a 2-site model for transcytolemmal water exchange. Minor (Dmin) and major (Dmaj) cell-diameters were determined by image analysis of FITC-wheat germ agglutinin stained sections.

RESULTS:
The hearts of L-NAME-treated and TAC mice developed hypertrophy (LV mass: TAC 113±16 and L-NAME 163.6 μg; all p<0.05 vs. controls). τic was significantly higher in L-NAME-treated animals (0.453±0.10 s; p<0.0001) and in TAC mice (0.255±0.04 s; p<0.001), compared to controls (0.193±0.07 s). τic correlated with the minor cell diameter (r=0.77, P<0.001), the major cell-diameter (r=0.5, p=0.02), and with LV mass (r=0.76, p<0.001). ECV in L-NAME-treated mice (0.395±0.047) was significantly higher (p<0.001) than in TAC (0.248±0.033; n.s. vs. controls) mice and controls (0.269±0.029).

CONCLUSION:
We validated a combined and non-invasive quantification of cell size and extra-cellular space expansion. The results in TAC mice demonstrate the ability to detect changes in cellular hypertrophy before expansion of the extracellular space and development of cardiac (interstitial) fibrosis.
Abstract 19869: Genome Wide Association Study of Perioperative Myocardial Infarction Following Coronary Bypass Grafting
Authors: Podgoreanu Mihai R , Kertai Miklos , Li Yi-Ju , Alexander John H , Newman Mark F , Smith Peter K , Mathew Joseph P
Published: April 2024

The incidence of perioperative myocardial infarction (PMI) after cardiac surgery can be as high as 19%, and is associated with long-term mortality and morbidity. Identification of populations at risk for developing large infarcts or alternatively indicating presence of a cardioprotective state, as well as responsiveness to a protective agent remain high-priority knowledge gaps. We sought to identify novel common genetic variants associated with PMI in a genome-wide association study (GWAS) of patients undergoing CABG.

Methods:
Using the Illumina 610quad chip, we conducted a GWAS for PMI in 1254 patients enrolled in the multicenter Genetics of Myocardial Adverse Outcomes and Graft Failure (GeneMagic) study, followed by a replication analysis in 644 patients from the Duke PEGASUS cohort. PMI was defined as CK-MB values ≥10xULN in the first two postoperative days, and was CEC adjudicated in the GeneMagic cohort. Sample and genotype QC analyses included assessing gender matching, autosome heterozygosity, cryptic relatedness, and population stratification, as well as filtering polymorphisms with minor allele frequencies <0.01 and departing from HWE.

Results:
Following QC, 1193 patients in discovery cohort (100 cases/1093 controls), and 588 patients in replication cohort (108 cases/480 controls), all of European descent, were analyzed at 519,499 markers. In replicated analyses, we identified 14 SNPs associated with altered susceptibility to PMI (12 with increased risk [OR 1.35-2.44] and 2 with decreased risk [OR 0.4-0.73]), p<0.01 in both cohorts. The chromosomal distribution of association tests p-values in pooled analyses in presented in Fig A, and a quantile-quantile plot of observed vs expected p-values in Fig B.

Conclusion:
Herein, we present a preliminary report of the first GWAS identifying multiple novel susceptibility loci for PMI. Further replication analyses in independent cohorts of cardiac surgical patients are ongoing.
Abstract 207: Postresuscitation Care and Outcomes of Out-of-Hospital Cardiac Arrest in Korea: A Nationwide Propensity Score Matching Analysis
Authors: Kim Joo Yeong , Shin Sang Do , Ro Young Sun , Song Kyoung Jun , Lee Eui Jung , Park Chang Bae , Hwang Seung Sik
Published: April 2024

Objective
: Active post-resuscitation care (APC) strategy showed improved out-of-hospital cardiac arrest (OHCA) outcomes in well controlled trials. This study aimed to determine whether APC is associated with improved OHCA outcomes in Korea, nationwide level.

Methods
: We used a national OHCA cohort data composed of hospital and ambulance data, including all EMS-treated OHCA survivors from January 2008 to December 2010. We excluded cases with presumed non-cardiac etiology, those without available hospital outcome data and those with age under 15 years old. The APC group is OHCA patients received coronary reperfusion therapy, therapeutic mild hypothermia, coronary artery bypass surgery (CABG), and pacemaker insertion as well as conservative intensive care (CIC). The primary and secondary outcome was survival to discharge and good neurologic outcome (cerebral performance category (CPC) 1 to 2). We extracted propensity matched sample to contol selection bias. Mutivariable logistic regression analysis was used and we adjusted for potential risk factors to calculate adjusted odds ratios (OR) and 95% confidence intervals (95% CIs).

Results
: Among 64,155 EMS-assessed OHCA patients with available outcome, 44,794 adults patients with presumed cardiac etiology were collected excluding non-cardiac etiology (n=17,970) and pediatric (n=1,391). Of these, 4,557 patients survived to admission were used for final analysis. 1,599 (35.1%) cases survived to discharge and 499 (11.0%) cases discharged with good neurologic recovery. 695 cases (15.3%) received any APC including mild hypothermia (n=377, 8.3%), reperfusion therapy (n=307, 6.7%), CABG (n=18, 0.4%), and pacemaker insertion (n=61, 1.3%). Survival to discharge rate was higher in APC group than CIC group (58.7% vs. 30.8%, p <0.001). Good neurologic outcome was also higher in APC group than CIC group (27.2% vs. 8.0%, p<0.001). Adjusted ORs of APC versus CIC group was 2.12 (95% CI 1.76-2.55) for survival to discharge and 2.53 (95% CI 1.99-3.21) for good neurologic outcome. For propensity score matched cohort, adjusted ORs for survival to discharge and good neurologic outcome of APC was significantly favor.

Conclusions
: The APC strategy in Korea increased by year and showed significant improved outcomes.
Abstract 216: Out-of-Hospital Cardiac Arrest Due to Drowning Among Children and Adults
Authors: Nitta Masahiko , Kitamura Tetsuhisa , Iwami Taku , Nadkarni Vinay , Berg Robert , Nishiuchi Tatsuya , Hayashi Yasuyuki ,   Japan Paediatric Resuscitation Study (PResS) Group
Published: April 2024

Background
: Favorable neurological outcome after out-of-hospital cardiac arrests (OHCAs) were more common among children than adults. However, little is known about the difference in outcomes after OHCA due to drowning.

Objectives
: The aim of this study is to assess the outcome after OHCA due to drowning between children and adults. Our hypothesis is that outcomes after OHCA due to drowning would be in better among children (<18 years old) compared with adults (>=18 years old).

Method
: This prospective population-based, observational study included all emergency medical service-treated OHCA due to drowning in Osaka, Japan, between 1999 and 2010 (excluding 2004). The primary outcome measure was neurologically favorable one-month survival defined as cerebral performance category (CPC) 1 or 2. Multivariate logistic regression analyses were used to account for factors associated with better neurological outcomes.

Results
: During the study period, 66,716 OHCAs were documented, and resuscitations were attempted for 62,048 patients (1,300 children [2%] and 60,748 adults [98%]). Among these OHCAs, 1,737 (3% of OHCAs) were due to drowning (68 children [4%] and 1,669 adults [96%]). The proportion of return of spontaneous circulation, hospital admission, one-month survival after OHCA due to drowning was significantly higher among children than adults (Table). The proportion of neurologically favorable one-month survival was greater among children than adults (4% [3/68] vs 1% [11/1669], p=0.015, crude odds ratio [OR]: 6.95 [95% confidence interval {CI}: 1.89-25.52]; adjusted OR: 3.69 [95% CI: 0.58-23.48]).

Conclusion
: This large OHCA registry showed that children had better outcomes after OHCA due to drowning compared with adults.
Abstract 220: Intralipid Fails to Rescue Bupivacaine-Induced Cardiotoxicity in the Presence of the Opioid Antagonist Naloxone
Authors: Partownavid Parisa , Umar Soban , Rahman Siamak , Sharma Salil , Eghbali Mansoureh
Published: April 2024

Introduction: Exogenous opioids such as morphine protect the heart against I/R injury. This action is mediated through opioid receptors as Naloxone, an opioid receptor antagonist, inhibits the cardioprotective effect of ischemic preconditioning. Here we explored the involvement of opioid receptors in lipid-mediated rescue of Bupivacaine-induced cardiac toxicity.

Methods: Young male SD rats (300-350 g) were anesthetized with ketamine (80 mg/kg) and xylazine (8 mg/kg) and ventilated with a ventilator. The M-mode echocardiography and Electrocardiograms were acquired throughout the experiment. Asystole was achieved with a single injection of Bupivacaine (10mg/kg over 20 s, intravenously), and resuscitation with Intralipid (5ml/kg bolus, and 0.5ml/kg/min maintenance) along with cardiac massage was started immediately. Some rats were pre-treated with different doses of Naloxone (1 mg/kg, 10 µg/kg, 5 µg/kg and 1 µg/kg) 2 min prior to inducing asystole with Bupivacaine.

Results: Administration of Bupivacaine resulted in asystole and Intralipid therapy improved the heart rate gradually within 10 min: 73.3±3.3 beats/min at 1min (23% recovery), 180±23 beats/min at 5 min (56% recovery), and 243±20 beats/min at 10 min (76% recovery, n=6). The left ventricular systolic function was also fully recovered in all rats within 5 min of lipid treatment as the ejection fraction (EF) and fractional shortening (FS) were similar to their baseline values (EF=70±3%, FS=40±3%, n=6)., Interestingly, Intralipid failed to rescue Bupivacaine overdose in rats pretreated with a high dose of Naloxone (1mg/kg) as there was no recovery of cardiac function within 10 min of lipid therapy (n=5). In rats pretreated with lower doses of Naloxone of 5 µg /kg and 10 µg /kg (n=4/group), the heart rate and cardiac function were partially recovered. Lowering the dose of Naloxone further to 1 µg /kg resulted in 76% recovery of the heart rate at 10 min. Complete recovery of the left ventricular systolic function was observed in this group within 10 min of lipid treatment as EF and FS were similar to their baseline values (EF= 73±3%, FS=43±3, n=4). .

Conclusions: The opioid receptor antagonist Naloxone abolishes lipid rescue of Bupivacaine-induced cardiotoxicity in a dose-dependent manner.
Abstract 224: Amplitude Spectrum Area Based Defibrillation Decision Greatly Improves Shock Success Rate and Accuracy During Prehospital Cardiopulmonary Resuscitation
Authors: Ristagno Giuseppe , Quan Weilun , Freeman Gary
Published: April 2024

Background.
We retrospectively evaluated the capability of “amplitude spectrum area” (AMSA) to predict the likelihood that a defibrillation (DF) would restore a perfusing rhythm during CPR in human victims of out-of-hospital cardiac arrest. We hypothesized that threshold values of AMSA could be identified and would increase DF success rate and accuracy.

Methods.
ECG data, including 1410 DFs, were obtained from 748 cardiac arrest patients from multiple areas in the US. A 4.1 secs ECG window ending at 0.5 sec before DF was analyzed and AMSA calculated prior to first DF and subsequent DFs delivered in cases of DF-resistant VF. Successful DF was defined as return of an organized rhythm within 60 sec. For first and subsequent DFs, AMSA threshold values were analyzed with regard to their ability to discriminate among successful and not successful DFs. Sensitivity, specificity, accuracy, and positive predictive value (DF success rate) of an AMSA based decision algorithm were calculated. The DF performance was then compared between two DF decision algorithms with and without AMSA threshold, respectively.

Results.
A total of 1221 qualified DF events from 607 patients, with 578 first DF attempts and 543 subsequent ones for DF-resistant VF, were included in the analyses. For the DF decision algorithm without AMSA, the DF success rate and accuracy were 27%/27% for the first DFs, 9%/9% for the subsequent DFs, respectively. An optimized AMSA threshold was found to be 14 mV-Hz for first DFs and 12 mV-Hz for subsequent ones. Incorporation of these AMSA thresholds into a DF decision algorithm increased both DF success rate and accuracy. The first DF achieved a DF success rate of 54% and an accuracy of 75% while subsequent DF attempts achieved 42% in DF success rate and 89% in accuracy. These results translated into an increase of DF success rate and accuracy by 100% and 180% for the first DFs, and 360% and 880% for the subsequent DFs.

Conclusions.
In this population, a defibrillation decision algorithm incorporating an AMSA threshold was confirmed to be capable to predict DF success with high accuracy. Different optimized AMSA thresholds can be selected for first and subsequent DF attempts to predict DF success with high accuracy may be selected in the case of first and subsequent DFs.
Abstract 229: Access to a Portable Miniaturized Extracorporeal Membrane Oxygenation System Increases Utilization for Cardiac Arrest Patients
Authors: Shah Atman P , Russo Mark J , Karol Janet , Beiser David , Bozzay Tom , Paul Jonathan , Deal Nathan , Nathan Sandeep , Retzer Elizabeth , Kommineni Maya , Edelson Dana , Jeevanandam Valluvan
Published: April 2024

Background:

Extracorporeal membrane oxygenation (ECMO) has improved outcomes in patients with cardiogenic shock (CS). Recent data and guidelines have recommended the use of venous-arterial (VA) ECMO in patients who have been successfully resuscitated from cardiac arrest (ROSC) to ameliorate the effects of post-resuscitation myocardial dysfunction. Use of ECMO often involves taking a patient to the operating room delaying the onset of care. We hypothesized that utilization of the Maquet Cardiohelp, a portable miniaturized ECMO system, in the cardiac catheterization laboratory (CCL), would increase use of ECMO for cardiac arrest patients.

Methods:

Cardiohelp (CH) ECMO was acquired in March 2012 by our tertiary care university hospital. We performed a retrospective analysis comparing the patients who received CH ECMO from March 2012 until June 2012 to those that received Centrimag (CM), a traditional ECMO circuit, in the in the 6 months prior to March 2012.

Results:

All patients were treated with femoral VA ECMO with antegrade perfusion distal via a percutaneous catheter in the superficial femoral artery. Overall, more patients were treated with CH compared to CM. Compared to patients who received CM, CH patients were more likely to have been referred for ECMO after ROSC from cardiac arrest and were more likely to have been transferred directly from the Emergency Department (ED). CM patients were slightly younger and were referred for ECMO treatment primarily due to cardiogenic shock (SBP3 pressors). 30 day survival was similar in both groups and there were no cases of stroke or limb ischemia.

Conclusions:

Use of the portable CH ECMO system with CCL initiation is associated with increased utilization of ECMO and particularly for the treatment of ED ROSC patients. This may be due to the portability of the device and existing relationships between the CCL and the ED. Rapid utilization of ECMO for these patients may lead to improved clinical outcomes.
Abstract 239: Out-of-Hospital Cardiac Arrest Survival Predicted at 24 Hours: The Application and Validation of a Novel Clinical Score
Authors: Albaeni Aiham , Eid Shaker M , Vaidya Dhananjay , Chandra-Strobos Nisha
Published: April 2024

Background
: Despite 50 years of research, survival prognostication is still dependant on clinical status at 72 hours. We developed and tested the accuracy of a 24 hour, novel clinical score to predict the probability of survival post non-traumatic cardiac arrest.

Methods
: In 170 cardiac arrest survivors admitted between 2004-2010, a predictive model was developed. Variables used in univariate analyses to generate the prediction equation were: Initial Rhythm VF/VT, Return of Spontaneous Circulation (ROSC) ≤20 minutes, Brian Reflex Score (BRS)≥ 3 at 24 hours, Bystander CPR, and use of ≥3 doses of epinephrine. Multivariate logistic regression then retained significant predictors in a 50% random training sample, 84 patients (pts) and tested these in the remaining 50% validation sample, 86 pts. The diagnostic efficiency of the model was assessed using ROC analysis.

Results
: Of 170 pts studied, mean age was 63 years(SD±15.7), 37 pts (21.7%) survived to discharge. The initial rhythm was VF/VT in 38 (22%), 58 (34%) had ROSC≤ 20 minutes, 34 (20%) had a BRS ≥3 at 24 hours, and 80(47%) received Hypothermia. Mean length of stay was 5.8 days (SD±7.8).The final model retained three predictors: VF/VT, ROSC≤ 20 minutes and BRS≥ 3 at 24 hours. Table below presents the probability of survival with presence/ absence of all combinations of these 3 predictors.

No single variable was robust in identifying the probability of survival (9%-17%). The presence of any 2 variables increases the probability to (55%-71%),however the presence of all 3 variables, in any patient increases the probability to 95%. The area under the ROC curve was 0.87 in the training sample and 0.84 in the validation sample.

Conclusion
: This study demonstrates that a score comprising 3 easily clinically, accessible variables correctly identifies survival following cardiac arrest. This score,like many other clinical scores, is incremental in predictive accuracy and warrant revalidation in larger cohort.
Abstract 242: A Standardized Template for Measuring and Reporting Dispatch Prearrival CPR
Authors: Tully Jeffrey , Dameff Christian , Murphy Ryan Anne , Dunham Aaron , Panczyk Micah , Stolz Uwe , Tobin John , Kotsur Brian , Karamooz Madalyn , Spaite Daniel , Bobrow Bentley ,   SHARE Study Group
Published: April 2024

Introduction:
Dispatch-Assisted CPR (DACPR) is a method for improving bystander response and survival from out-of-hospital cardiac arrest (OHCA). No standardized methodology exists for measuring and reporting this intervention. We developed a template for collecting, analyzing, and reporting DACPR.

Methods:
Five trained evaluators reviewed 161 suspected OHCA audio recordings from an urban 911 dispatch center. Key metrics in the evaluation of pre-arrival CPR instructions were recorded on a structured data form: dispatch recognition of OHCA, time interval to initiation of CPR instructions, and interval to first chest compression. Using the tool, evaluators identified common themes in the delivery of DACPR.

Results:
See Figure for template and results.

Conclusion:
Utilizing key components of the AHA DACPR Scientific Advisory Statement, we developed a method for collecting, analyzing, and reporting key metrics for DACPR that could act as a template to help improve the DACPR process and increase rates of Dispatch-Assisted bystander CPR (DA-BCPR). DACPR data collected in this manner may help identify targets for improvement in the prehospital response to OHCA. In addition, the template may support collaborative, inter-system investigations by providing a standardized, Utstein-type approach to data reporting.
Abstract 243: Pulsatile Versus Nonpulsatile Emergency Cardiopulmonary Bypass: Impact on Early Regional Brain Perfusion After Lethal Cardiac Arrest in Rats
Authors: Boller Manuel , Jung Sung Koo , Yin Tai , Becker Lance
Published: April 2024

Background: An increasing amount of clinical data suggests that emergency cardiopulmonary bypass (ECPB) is an effective tool for resuscitation from prolonged cardiac arrest. Next to controlling pharmacological components of the reperfusate, ECPB also allows definition of physical characteristics of reperfusion. Pulsatile reperfusion is a intriguing strategy but has not been studied in the setting of ECPB despite its technical feasibility. Thus we aimed at testing the influence of a pulsatile reperfusion component to early brain perfusion after lethal cardiac arrest in a rodent ECPB model.

Methods: After anesthesia and instrumentation, male Sprague-Dawley rats (448±41g) underwent 20 min of untreated asphyxial arrest and were resuscitated with normothermic ECPB with either pulsatile (150 beats/min; 50 mL/min; n=8) or non-pulsatile flow (50 mL/min; n=8). No vasopressors were administered. ROSC was prevented by occluding the right ventricle. At 3 min, FITC-dextran 70 was injected into the bypass circuit. Two minutes later ECPB was stopped, the brain removed and brain slices at defined levels (Bregma -0.3 mm, -1.4 mm, -3.3 mm, -11.3 mm) mounted for fluorescent microscopy and blinded quantification of the area of FITC-stained perfused cerebral microvessels. Perfused areas were quantified for the whole brain, cortex, caudate putamen and hippocampus.

Results: The overall perfused cortical area (41±13%) was significantly higher than the non-cortical area (20±11%), with a trend towards better perfusion with pulsatile bypass in the deeper brain regions (p=0.07). While no differences in mean arterial blood pressure (MAP) between groups were present, perfused areas in putamen (p=0.04) and hippocampus (p=0.03) were significantly higher in animals treated with pulsatile ECPB.

Conclusions: The data suggests that pulsatile ECPB may be of benefit to improve perfusion of deeper brain regions after prolonged cardiac arrest and especially of those areas known to be vulnerable to cerebral hypoxia/ischemia. Additional studies are warranted to further define the role of pulsatile ECPB for resuscitation from lethal cardiac arrest.
Abstract 247: The Impact of the AHA Guidelines on Dispatch-Assisted Cardiopulmonary Resuscitation
Authors: Dameff Christian , Tully Jeffrey , Murphy Ryan Anne , Dunham Aaron , Panczyk Micah , Stolz Uwe , Tobin John , Karamooz Madalyn , Spaite Daniel , Bobrow Bentley , Ewy Gordon ,   SHARE Study Group
Published: April 2024

Background:
The wide variability in bystander CPR (BCPR) may be explained, in part, by how thoroughly systems implement dispatch-assisted CPR (DACPR) for out-of-hospital cardiac arrest (OHCA). The extent to which the recommendations in the recently-published AHA DACPR Scientific Advisory Statement have been implemented and their impact remains unknown. The purpose of this study was to measure the impact of implementing these recommendations in an urban 9-1-1 dispatch center. We hypothesized that this intervention would decrease several key dispatch time intervals and increase rates of BCPR.

Methods:
Prospective before/after observational study of Guideline-based dispatcher training on 5 performance measures: 1) time interval from call receipt to dispatcher recognition of arrest; 2) interval from call receipt to start of CPR instructions; 3) interval from call receipt to first chest compression; 4) % of cases where instructions were started; 5) % of Dispatch-Assisted BCPR (DA-BCPR). Calls were reviewed to determine the need for CPR and data entered into a structured data form. Dispatchers were trained according to AHA DACPR Guidelines using in-person and online modalities. Fisher’s exact and Kruskal-Wallis tests were used to assess statistical significance with α = 0.01 (multiple hypothesis testing).

Results:
Baseline: 161 suspected OHCA recordings from 10/10/10 to 3/13/11. Post intervention: 285 recordings from 11/7/11 to 1/15/12. See Table.

Conclusion:
In this 9-1-1 Dispatch Center, implementing the latest AHA DACPR Guidelines significantly improved the time interval to the start of CPR instructions and to first compression. In addition, there were significant increases in the proportion of OHCAs where pre-arrival CPR instructions were started and in dispatch-assisted bystander CPR rates. This intervention holds promise for improving BCPR rates on a large scale.
Abstract 267: Airway Pressure Is a Valid Surrogate for Intrapleural Pressure During CPR
Authors: Kwon Younghoon , McKnite Scott , Matsuura Timothy , Merriam Andrew , Salverda Bayert , Yannopoulos Demetris
Published: April 2024

Background:
Using direct measurement of intrapleural pressure (Ppl), we sought to assess true intrathoracic pressure during various interventions of CPR and to explore its relationship with airway pressure (Paw). We hypothesized that Ppl would correlate with Paw and with coronary (CPP) and cerebral (CePP) perfusion pressures.

Methods:
Ppl catheter was inserted into right anterior aspect of pleural cavity. Paw, right atrial (Pra), aortic and intracranial (ICP) pressures were recorded continuously. Proper placements were confirmed in all animals post mortem. Following 4 minutes of untreated ventricular fibrillation in 6 anesthetized female farm pigs (34 ± 2 kg), CPR was performed in the following sequence for 2 minutes per each intervention. Standard CPR (sCPR), Active compression decompression (ACD) CPR, ACD+ inspiratory impedance threshold device (ITD) CPR, ACD + intrathoracic pressure regulator (ITPR) CPR. Data were collected during last 20 seconds of each intervention.

Results:
Highest and lowest mean Paw and Ppl were observed during sCPR and ACD +ITPR CPR respectively. Mean Paw showed modest correlation with mean Ppl. (r2=0.15, p=0.06). After adjusting for variance between the animals, significant correlation was observed (r
2
=0.81, p<0.0001). In contrary, no significant correlation was observed between mean Pra and Ppl.  Among intrathoracic pressure variables mean Ppl and Paw (not mean Pra) showed significant inverse correlations with both CPP and CePP. Mean Pra was strongly correlated with ICP. (Table)  

Conclusion:
A significant correlation of mean Paw with Ppl provides validity of using Paw as a surrogate measurement to monitor intrathoracic pressure during standard CPR and ACD assisted interventions. Table) Within animal correlation between intrathoracic pressure variables and central perfusion pressures.
Abstract 279: Time to Awakening After Cardiac Arrest: How Long Should We Wait?
Authors: Peberdy Mary Ann , Ornato Joseph P , Donnino Michael , Cocchi Michael N , Rittenberger Jon , Callaway Clifton W , Gaieski David F , Abella Benjamin S , Clore John N ,   for the National Post Arrest Rsch Consortium (NPARC) Investigators
Published: April 2024

Background: Studies performed prior to the use of therapeutic hypothermia (TH) suggest the optimal timeline for prognostication after cardiac arrest (CA) is on day 3 but this may not be generalizable to patients (pts) treated with TH. Current guidelines state that futility should not be declared until greater than day 3 after ROSC in hypothermic pts.

Purpose: To identify the time to awakening in post arrest patients treated with TH.

Methods: Post hoc analysis of a prospective, non-interventional, multi-center trial. Data from 111 consecutive pts from 7-1-11 thru 3-31-12 were analyzed using PASW v20. Results are presented as median [25th, 75th percentiles]. Time to awakening is defined as the number of calendar days from ROSC to purposefully following commands.

Results: Fifty-one of the 111 patients (46%) survived to discharge. Awakening occurred in 39/51 (77%) patients who survived to discharge vs. 1/60 (3%) who awakened and died. Median time to awakening in those who awakened and survived to discharge was 1 [.25, 2] day (range 0-28 days). It took 4.9 days for 90%, and 11.9 days for 95%, of those who awakened to do so. Characteristics of all patients and those who awakened and survived to discharge stratified by time of awakening after ROSC are shown in the Table.

Conclusions: Awakening and good neurological outcome occurs in pts treated with TH who remain comatose on day 3 after CA, irrespective of the first documented rhythm. Most patients who awaken will do so by the end of day 4, but 10% require longer. Our data suggest that it may be necessary to wait >3 days to allow adequate time for awakening after CA in patients treated with TH. Allowing patients adequate time for neurological recovery requires longer hospital stays and additional resources. Further study should prospectively evaluate the timeframe for expected neurological recovery in CA pts treated with TH.
Abstract 281: Does Chest Compression-Only CPR Provide Meaningful Gas Exchange in Humans?
Authors: Roosa Jason , Kitamura Brian , McCarty Kyle , Page Rianne , Roque Pedro , Silver Annemarie , Spaite Daniel , Stolz Uwe , Vadeboncoeur Tyler , Bobrow Bentley ,   SHARE Study Group
Published: April 2024

Background:
During CPR in animals, chest compressions (CC) may produce passive volumes large enough to provide adequate ventilation. In humans, this mechanism may explain why continuous CCs have been associated with improved survival. We quantified the volume of passive ventilation during emergency department (ED) CCs to determine if compression-only CPR (COCPR) provides clinically significant gas exchange during resuscitation.

Methods:
In an urban ED, continuous flow and volume of air exhaled through an endotracheal tube were measured during the CC phase of manual CPR (between ventilations) with NICO monitors (Philip/Respironics) and recorded using LabView (National Instruments). Gas exchange with CC was quantified using Matlab (Mathworks) as the area under the flow curve (figure). CC quality was measured using accelerometer-based technology (R Series, ZOLL Medical).

Results:
Eight patients (6 male) aged 37-83 yrs [median age 51 yr (IQR 43-56)] who suffered out-of-hospital cardiac arrest (CA) and were transported and treated with CC in the ED were included. A total of 548 CCs [median depth 1.89 in (IQR=1.66, 2.29), median rate 128 CC/min (IQR=122-134) were analyzed over 30 min of CPR. Median tidal volume per CC was 17.3 mL (IQR=5.9-22.4). This was considerably less than measured dead space in all patients (median 118mL, IQR=93-143), regardless of CC depth. The figure illustrates a typical tracing in which ventilation volume dwarfs any passive ventilation occurring with CC.

Conclusion:
Late in CA, passive ventilation occurring during CCs appears to produce considerably less gas exchange than calculated dead space. The effectiveness of passive ventilation during early stages of CPR, when chest and lung compliance are greater, remains unknown. However, these findings suggest that the benefits of COCPR strategies may be related to reliably higher CC fraction and/or prevention of the negative effects of hyperventilation rather than from any passive ventilation.
Abstract 301: Does Refibrillation Occur in High-Impedance Patients Who Have Received Shocks Using Biphasic Waveforms with Longer Pulse Durations?
Authors: Di Maio Rebecca , Crawford Paul , Brody David , Howe Andrew , McCanny Paul , Crawford Lauren , Crispino-O’Connell Gloria , Adgey Jennifer
Published: April 2024

Introduction

The electrical impedance between defibrillator pads has a significant effect on the ability of defibrillators to deliver a therapeutic shock. A variety of technologies are used to deliver the chosen therapeutic shocks safely yet effectively across a wide range of patient impedances.

Defibrillators will not deliver a shock above pre-set impedance. We assessed the hypothesis that devices which have pulse durations over 20ms may predispose the patient to spontaneous re-fibrillation after a successful shock.

Methods

Two defibrillators were tested. Device A (A) limited the current delivered and in high impedance patients would extend the pulse duration as needed to deliver the selected energy while staying below the current limit. Device B (B) would truncate the shock to restrict the pulse duration but operated with higher currents. A high impedance porcine model of ventricular fibrillation (VF) was created. Following pilot work we were unable to demonstrate any relationship between pig mass and impedance. Therefore to create high impedance it was necessary to place resistors in series with the pig between the defibrillator under test and the pads.

Results

From the pilot studies we determined that an impedance of approximately 95ohms resulted in a pulse duration of 20ms when device A delivered a 200J shock. A total of 5 anaesthetised pigs weighing 17-20kg (18.8kg) where used with 168 episodes of VF where impedance was greater than 100 ohms are included in the results. Two energies were tested for A (150 and 200J). B only delivers shocks at a single energy (150J). No re-fibrillation was observed in any patient after any shock.

Conclusions

This study failed to show any evidence of re-fibrillation even at pulse durations longer than 20ms with either device.