bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 19715: Silencing of Mineralocorticoid Receptors in the Heart Blunts the Anrep Effect
Authors: Pérez Néstor G , DÍaz Romina G , Morgan Patricio E , Cingolani Horacio E
Published: April 2024

The stretch-induced increase of cardiac force is biphasic. A first abrupt increase (Farnk-Starling mechanism) is followed by a slower response that takes minutes to develop, which is believed to be the in vitro manifestation of the Anrep effect. This slow force response (SFR) is due to an increase in the intracellular Ca
2+
transient. Although the cause of the increase in Ca
2+
is controversial, an increased NHE1 activity as result of a stretch-triggered autocrine/paracrine mechanism was proposed to be crucial. Furthermore, based on pharmacological approaches we have recently suggested a role for mineralocorticoid receptors (MR) activation in the signaling pathway to the SFR. However, a recent report in smooth muscle cells called attention to the fact that MR inhibitors spironolactone or eplerenone can also affect signaling pathways that do not depend on MR activation. Therefore definitive evidence about the participation of MR in the SFR development needs of MR silencing by molecular techniques. In this study, an interference RNA sequence (small hairpin) able to mediate specific MR knockdown was incorporated into a lentiviral vector (l-shMR) and injected into the left ventricular wall of rat myocardium. Injection of a vector expressing a non-silencing sequence (scramble) served as control. Rats were sacrificed one month after injection. Myocardial MR protein expression was determined and the SFR as well as the stretch-triggered NHE1-mediated increase in pH
i
in the absence of bicarbonate was evaluated in isolated papillary muscles. Hearts with l-shMR showed reduced MR protein expression (100 ± 5.7 %, n=8, scramble vs. 57 ± 5.6 %, n=9, l-shMR, P<0.05) as well as inhibition of the SFR (in % of initial rapid phase: 125.9 ± 1.8, n=8, scramble, vs. 103.9 ± 1.3, n=8, l-shMR, P<0.05) and of the stretch-induced increase in pH
i
in bicarbonate free medium (ΔpH units: 0.156 ± 0.025, n=7, scramble, vs. 0.009 ± 0.015, n=10, l-shMR, P<0.05). These data provide unequivocal support to our proposal that MR activation is crucial in the stretch-triggered myocardial mechanism leading to NHE1 activation that determines the Anrep effect.
Abstract 19756: Association of Increased PTEN-Induced Putative Kinase 1 (PINK1) Expression and Oxidative Damage in Gastrocnemius Myofibers of Patients with Peripheral Arterial Disease
Authors: Koutakis Panagiotis , Casale George P , Miserlis Dimitrios , Thompson Jonathan R , Papoutsi Evlampia , Duy Ha M , Swanson Stanley A , Zhu Zhen , Pipinos Iraklis I
Published: April 2024

Introduction:
Oxidative damage (OxD) determined as protein adducts of 4-hydroxy-2-nonenal (HNE) is increased in gastrocnemius myofibers of patients with peripheral arterial disease (PAD) and correlates with disease progression. Mitochondria in PAD gastrocnemius exhibit structural damage and respiratory dysfunction; however, the extent of mitochondrial damage and its relationship to OxD have not been determined. PINK1 is a glycoprotein normally expressed in low abundance on the mitochondrial external membrane. Mitochondrial damage signaled as loss of ion potential across the external membrane produces a marked increase in PINK1, which initiates mitophagy. In this study, we tested the hypothesis that mitochondrial damage is 1) prevalent among gastrocnemius myofibers of PAD patients and 2) linked to OxD.

Methods:
Gastrocnemius biopsies were collected from five PAD patients with claudication and five controls matched on the basis of age, gender, smoking history and type II diabetes. Biopsy specimens were fixed in methacarn, embedded in paraffin, sectioned and mounted to glass slides. Fluorescence labeled PINK1 protein and HNE adducts in individual myofibers, were quantified by quantitative fluorescence microscopy and expressed as mean pixel intensity in gray scale units (gsu) corrected for background.

Results:
PINK1 protein expression was increased (p=0.008) in PAD (mean ± S.E.M.; 494.78 ± 0.02 gsu) compared to control myofibers (102.45 ± 0.02 gsu) of the gastrocnemius. PINK1 was increased in 93% of the PAD myofibers. The association of increased (greater than two standard deviations above the control means) PINK1 expression and HNE adducts was determined for PAD myofibers. HNE adducts were increased in 67% of a random sample of PAD fibers expressing increased PINK1.

Conclusions:
Increased expression of PINK1 protein in the gastrocnemius myofibers of PAD patients with claudication, has established the presence of irreversible mitochondrial damage in a large proportion of myofibers. Elevation of OxD in 67% of PAD myofibers expressing increased PINK1 links OxD and mitochondrial damage. The data are consistent with a contribution of OxD to myofibers in PAD gastrocnemius, by damaged mitochondria.
Abstract 19795: S-glutathionylation of eNOS occurs in Clinical Obstructive Sleep Apnea (OSA)
Authors: Varadharaj Saradhadevi , Wannemacher Jacob , Patt Brian , Rao Hemalatha , Reyes Levy , Khayat Rami , Zweier Jay L
Published: April 2024

Obstructive sleep Apnea (OSA) is a risk factor for cardiovascular disease and causes vascular endothelial dysfunction (VED); however, the basis of this VED is unknown. Increased oxidant production is observed in the endothelium of OSA patients. We have recently demonstrated that under oxidant stress eNOS uncoupling is triggered by S-glutathionylation of specific cysteines including C689 of the reductase domain. Since OSA is associated with oxidant stress, we hypothesized that S-glutathionylation of eNOS may occur in OSA and trigger eNOS uncoupling.

Methods:
13 patients with recently diagnosed OSA and 10 healthy individuals with low cardiovascular risk were studied. OSA patients underwent subcutaneous forearm biopsy and Doppler measurements of endothelial function by flow mediated dilation (FMD) prior to, and 12 weeks after initiation of treatment. Non-OSA control patients also provided FMD measurements and biopsies. eNOS S-glutathionylation was studied using specific anti-eNOS C689 S-glutathionylation antibody. Superoxide
·(
O
2

_
)

levels in the microcirculation were determined using fluorescent probe DHE in the absence or presence of the SOD mimetic, MnTBAP.

Results:
OSA patients had impaired FMD, compared to non-OSA controls, which decreased after 12 weeks of treatment with CPAP. Immunohistochemical analysis of frozen sections from OSA patients using anti-eNOS C689 glutathionylation antibody revealed that prominent eNOS S-glutathionylation was present in the endothelium of OSA patients that was abolished by treatment with the reducing agent DTT, and was attenuated following CPAP treatment and absent in healthy control subjects. In association with these findings,
·
O
2

_

production from the endothelium was also decreased with CPAP treatment in OSA patients.

Conclusions:
These findings demonstrate that eNOS S-glutathionylation occurs in OSA and is associated with endothelial dysfunction with increased superoxide and decreased NO availability.
Abstract 19803: TMEM88: A Novel Regulator of Cardiac Development Identified Through Chromatin Dynamics
Authors: Palpant Nathan , Stoick-Cooper Cristi , Pabon Lil , Moon Randall , Murry Charles
Published: April 2024

Cardiac development is dependent on the biphasic activities of Wnt/β-catenin signaling where it is required for mesoderm development but must be blocked to specify the cardiogenic mesoderm. The mechanism mediating this inhibition of Wnt/β-catenin signaling in cardiac progenitor cells is not known.

Methods and Results.
RNA seq was used to analyze genes most highly induced in the cardiac progenitor cell during cardiac differentiation of human ES cells. Transmembrane protein 88 (TMEM88) was identified for further study. In line with previous work showing TMEM88 binds Disheveled by a C-terminal PDZ binding motif, we used transgenic hES cells to show that TMEM88 blocks Wnt/β-catenin signaling during cardiac differentiation. Chromatin dynamics showed marked suppression (H3K27me3) of this locus in the transition through mesoderm with a switch to an activated state (H3K4me3) in the cardiac progenitor; a signature resembling other genes involved in mediating cell fate changes such as transcription factors. By qPCR, TMEM88 is highly up-regulated prior to Nkx2.5 and Isl1 expression. In situ hybridization of developing zebrafish embryos showed expression of TMEM88 specifically in the cardiogenic ventro-lateral mesoderm overlapping the expression profile of cardiac transcription factors such as Nkx2.5 and MEF2c. Short hairpin RNA targeting the TMEM88 transcript was used to determine its requirement for cardiac differentiation of hES cells. Suppression of TMEM88 resulted in a failure to specify the cardiac lineage based on significantly reduced Nkx2.5, Tbx5, and cTnT expression. Linear regression analysis revealed a dose dependent effect of increased TMEM88 significantly correlating with higher cTnT expression. In vivo, morpholino knockdown of TMEM88 in zebrafish markedly alters heart development with some embryos failing to generate a heart. Phylogenetic analysis of TMEM88 orthologs identifies the expression of this gene only in vertebrate chordates.

Conclusion.
These data show that TMEM88 is required for cardiac development in vitro and in vivo acting mechanistically in a cell autonomous manner to inhibit Wnt/β-catenin signaling during the specification of the cardiac lineage in progenitor cells of the primordial heart.
Abstract 19809: Intrinsic Right Ventricle Dysfunction is a Major Cause of Post LVAD Mortality
Authors: Wang Lin , Zucker Mark , Cohen Marc , Amponsah Michael , Baran David , Camacho Margarita , Chen Chunguang
Published: April 2024

Background:
Right ventricular (RV) dysfunction after left ventricular assistant device (LVAD) confers significant challenges for post-device managements and increases mortality. The purpose of this study was to test the hypothesis that intrinsic RV myocardial dysfunction measured by 2-D echocardiography speckle tracking imaging prior to LVAD implantation is the most common cause of post-LVAD failure.

Methods:
Thirty-nine patients who underwent Heartmate II LVAD placement from 2010 to 2011, and 10 age-matched controls were studied. Pre- and post-operative clinical, and echocardiographic data were prospectively collected for LVAD database. RV longitudinal myocardial velocity, strain, and strain rate were measured retrospectively using an off-line speckle-tracking analysis software.

Results:
Of the 39 LVAD recipients, 24 patients developed acute RV failure immediately post LVAD implantation, among which 13 patients recovered from RV dysfunction after LVAD adjustment and medical management, while 11 patients with intrinsic RV dysfunction as identified by significantly lower global RV peak myocardial velocity, strain, and strain rate prior to LVAD (p<0.05), eventually required RVAD and/or death despite optimal medical therapy. Intrinsic RV myocardial dysfunction often cannot be completely improved by LVAD implantation alone and may be exaggerated by septal shifting caused by emptying or decompressing LV, thus, worsening severe or deteriorating RV dysfunction which eventually requires RVAD or leads to death. Eight of 11 patients including all 7 RVAD patients died within 6 months from LVAD implantation had a peak longitudinal systolic RV global strain of -3% or lower (absolute value). Twenty-four of 27 (88%) patients with the global RV strain higher than -3% (absolute value) survived without RVAD (p<0.05).

Conclusions:
Poor intrinsic RV myocardial function is often worsened in LVAD patients and is a leading cause for a high LVAD mortality.
Abstract 19823: Whole-Exome Sequencing in an Extended Family with Myocardial Infarction Identified a Potential Functional Mutation in PDE5A
Authors: Brænne Ingrid , Medack Anja , Stark Klaus , Field Sarah , Tuna Salih ,   Cardiogenics Consortium, Deloukas Panos , Samani Nilesh J , Hengstenberg Christian , Schunkert Heribert , Erdmann Jeanette
Published: April 2024

Objective:
Despite the enormous success of genome-wide association studies (GWAS), only a small fraction of the expected heritability for CAD and MI is explained so far. One drawback of GWAS is the lack of power to detect rare yet functionally important variants. Rare variants may however cluster in families.

Aim:
Studying extended MI-families by means of whole-exome sequencing (WES) may give new insights in the pathophysiology of CAD.

Methods:
We analyzed a German MI family with 9 affected and 46 unaffected individuals. We sequenced three distantly related affected family members using the Agilent SureSelect 38 Mb Kit. Variants were validated by Sanger re-sequencing.

Results
and Discussion: The three sequenced individuals shared 22,048 variants. Filtering for SNPs with a frequency >1% in dbSNP left 2,845 variants. Of these, 988 variants are conserved (46 Way) and again 772 were located outside of regions of segmental duplication. 23 potentially function-altering variants were left after filtering based on an avsift score >0.05 and ,,HIGH“ effect predicted by Annovar and SNPEFF respectively. To further reduce the number of variants, we focused on those not in dbSNP. This approach left two variants of which only one was successfully validated by Sanger re-sequencing. The variant is a new single nucleotide substitution (A>T) that causes a stop-codon (g.120548312T>A) in the first exon of one of the three known PDE5A transcripts. In addition, the variant lies in a strong regulatory region and may hence also influence transcription. We genotyped all family members available for genetic analysis and found that the variant co-segregates with the disease. Previous independent linkage studies show that the variant lies in a linkage region (LOD=2.63; p=0.0003) which supports the hypothesis that the identified variant is truly disease-causing. To determine whether the variant is found in unrelated individuals we genotyped 2,012 cases and 2,808 controls. Of the cases 0.1% carry the variant, of the controls only 0.03% .

Conclusion:
We have in this study identified a new potentially MI-causing variant in the PDE5A gene using WES. Upcoming functional analyses will help us to unravel the disturbed mechanisms and provide us with new insights in the pathogenesis underlying CAD.
Abstract 217: Presenting Rhythm and Outcome Following In-Hospital Cardiac Arrest in the United Kingdom: Results from the National Cardiac Arrest Audit
Authors: Patel Krishna , Gallagher Edel , Nolan Jerry , Soar Jasmeet , Harrison David , Rowan Kathryn
Published: April 2024

The National Cardiac Arrest Audit (NCAA) is a clinical audit of in-hospital cardiac arrest that aims to improve resuscitation care and outcomes in the United Kingdom (UK). NCAA is a collaboration between the Resuscitation Council (UK) and the Intensive Care National Audit & Research Centre (ICNARC) and is subscription-based. Inclusion criteria are all individuals (excluding neonates) receiving chest compressions and/or defibrillation and attended by a hospital-based resuscitation team (or equivalent) in response to an emergency call. Of 136 hospitals now participating, 83 had data for the period 1 April 2011 to 31 March 2012 and were included in the analysis. These hospitals were distributed across England and Wales and 43% were teaching hospitals. A total of 8,867 in-hospital cardiac arrests were reported for 8,499 patients (range 6 to 360 across individual hospitals). Mean age was 73 years and 57% were male. Of the 7,936 (90%) arrests with a known presenting rhythm, 4,201 (53%) presented with PEA, 2,157 (27%) asystole, 1,032 (13%) VF, 470 (6%) VT and 76 (1%) with bradycardia with a pulse. Overall, return of spontaneous circulation (ROSC) for > 20 minutes was achieved following 4,006 (45%) arrests and 20% survived to hospital discharge. ROSC for > 20 minutes and hospital survival varied substantially by presenting rhythm and by hospital. For example, after VF arrest, overall, 48% of patients survived to hospital discharge but this varied considerably across hospitals (Figure 1). These data indicate the need for an accurate, multivariable risk model, incorporating presenting rhythm and other important risk factors, to be able to assess performance across UK hospitals.
Abstract 221: The Use of Invasive Hemodynamic Monitoring in Evaluating Resuscitative End Points in Post--Cardiac Arrest Therapeutic Hypothermia (COMICA Study Group)
Authors: Grossestreuer Anne V , Perman Sarah M , Leary Marion , Donnino Michael W , Cocchi Michael N , Peberdy Mary Ann , Ornato Joseph P , Clore John N , Callaway Clifton W , Rittenberger Jon C , Abella Benjamin S , Gaieski David F
Published: April 2024

Introduction:
Patients who suffer from post-cardiac arrest syndrome (PCAS) often exhibit an inflammatory response similar to a sepsis syndrome. Invasive hemodynamic monitoring of resuscitative endpoints has been proven to impart better mortality outcomes in sepsis and has been recommended for goal-directed management of PCAS patients.

Hypothesis:
Centers engaged in aggressive post-cardiac arrest care will utilize invasive hemodynamic monitoring to ascertain adequacy of resuscitative endpoints including central venous pressure (CVP) and central venous oxygen saturation (ScvO
2
).

Methods:
This study is a collaboration of 4 centers with aggressive PCAS and therapeutic hypothermia protocols. It is a secondary analysis from prospectively collected data of out-of-hospital cardiac arrest patients who underwent TH. The primary objective was to determine the use of invasive hemodynamic monitoring in the care of PCAS patients undergoing TH. The secondary objective was to determine if either CVP or ScvO
2
were associated with neurologic outcome measured as cerebral performance category (CPC), dichotomized into “good” (1 or 2) or “poor” (3, 4 or 5). Study variables were abstracted at baseline, 12, 24, 36 and 48 hrs.

Results:
A total of 111 patients were enrolled. Patients were 61 ± 16.8 yrs, 59.5% male, and had an initial rhythm of VF/VT in 50.5% of cases. At baseline, 11% (12/111) of patients had a CVP recorded and 3.6% (4/111) has ScvO
2
measured. During the middle 24 hrs, an average of 65% (72) of patients had CVP recordings and 21.6% (24) of patients had ScvO
2
recorded. ScvO
2
values were not different between patients with good versus poor neurologic outcome. Lower CVP measurement was associated with better neurologic outcome.

Conclusion:
ScvO
2
was infrequently utilized in this cohort of PCAS patients undergoing TH. CVP was utilized at higher rates, and lower CVP recordings were correlated with better neurologic outcome.
Abstract 237: Cerebral and Somatic rSo2 Monitoring During Pediatric Cardiopulmonary Resuscitation
Authors: Abramo Thomas J , Meredith Mark , Locklear Mathew , Estrada Cristina E
Published: April 2024

Pediatric resuscitation/arrest has no assessment for tissue resuscitative efforts. Patients have inadequate tissue perfusion despite adequate systemic perfusion during resuscitation. Traditional methods for effective resuscitation have inherent flaws and don’t assess tissue resuscitation. Resuscitated patients by global methods, have significant tissue hypoxia. Refinement in goal directed therapy is to detect tissue resuscitation effects. During resuscitation, better endpoints are needed to guide resuscitation and endpoints. Near-infrared spectroscopy (NIRS) permits noninvasive readings of cerebral and somatic rSO2 tissue saturation. NIRS in adult resuscitations is predictor for survival and neurological outcome. A 15% rSO2 means no detectable tissue O2Hgb. A 95% rSO2 is interpreted as increased perfusion with no tissue O2 extraction.

Purpose: Retrospective analysis of Pediatric ED (PED) Resuscitation/CPR cases with cerebral & somatic rSO2 monitoring.

Methods: 1/09- 2/12 PED patients with resuscitation/CPR had noninvasive monitoring with cerebral & somatic rSO2 monitoring. Probes were placed on left & right forehead & right deltoid. Recordings were every 30 seconds. Medical records and autopsy were reviewed.

Results: Twenty nine patients were monitored Age 9 wks -16 yrs with 75% males. All patients expired. Patient’s etiology were Trauma or Medical: Sepsis, SUID, Drowning, Ingestion.

Conclusion: Preliminary data shows unique Cerebral & Somatic rSO2 monitoring in pediatric resuscitation and CPR. As in adult studies, cerebral and somatic rSO2 for our patients showed similar rSO2 of 95% and 15%. Small sample size precludes definitive conclusions. Our observations shows cerebral and somatic rSO2 gives real-time information on tissue oxygenation during pediatric resuscitations. A large validation study using cerebral and somatic rSO2 with global monitoring is warranted.
Abstract 244: Defibrillation Efficacy Is Not Influenced by Duration of Preshock Pause
Authors: Brouwer Tom F , Walker Robert G , Chapman Fred W , Koster Rudolph W
Published: April 2024

Background

A prior small study reported a strong relationship between pre-shock pause duration (PreSP) and 1st shock defibrillation efficacy during cardiac arrest resuscitation. We examined the relationship between PreSP and defibrillation efficacy across all shocks in a large cohort of out-of-hospital cardiac arrest (OHCA) resuscitations.

Methods

In an observational study of prospectively collected data, we enrolled all patients with cardiac cause OHCA presenting with VT/VF during calendar year 2009 in five EMS systems. Continuous ECG and impedance recordings from all defibrillators used during resuscitation were reviewed to measure PreSP and determine outcome for all shocks. Defibrillation success was defined as removal of VF for at least 5 seconds post-shock.

Results

Of 902 analyzable biphasic shocks to 281 patients, 763 successfully terminated VF (85%). The median (IQR) PreSP did not differ significantly between successful and failed shocks [8 (4,17) vs 7 (5, 15) sec, p=0.34]. No significant differences were found when analyzing just first shocks [9 (4,18) vs 7 (4,15), p=0.33], just AED shocks [20 (17,23) vs 19 (15,21), p=0.31], or just manual shocks [7 (4,15) vs 7 (4,13), p=0.97]. When grouped by PreSP duration in 10-sec increments, there was no significant trend in shock efficacy with increasing pause duration (Figure, p=0.06). In a univariate regression, there was no significant relationship between first-shock PreSP duration and successful VF termination [OR = 1.15 for every 5-second increase (0.91, 1.47)].

Conclusion

Defibrillation success is not associated with pre-shock pause duration.
Abstract 249: Cardiac Arrest in the Emergency Department: A Comparison of Pediatric and Adult Outcomes and Care Processes
Authors: Donoghue Aaron , Abella Benjamin , Merchant Raina , Berg Robert , Nadkarni Vinay
Published: April 2024

Background: About 10% of in-hospital cardiopulmonary arrest (CPA) events occur in the Emergency Department (ED). Published outcomes from CPA in the ED are discrepant between adults and children, with much worse survival among children. Reasons for these differences are unclear. We hypothesize a greater prevalence of unfavorable cardiorespiratory physiology among pediatric patients, and less optimal processes of care as a result of lower frequency occurrences among children in the ED.

Methods: Retrospective cohort study from the Get With The Guidelines - Resuscitation database. All patients whose CPA event occurred in the ED were included. Univariate comparison between children (age <18 yo) and adults (age > 18 yo) was done for Utstein outcomes (ROSC, 24 hr survival, survival to discharge) as well as patient factors (illness category, pre-existing conditions), event factors (initial rhythm, pulse sequence, total duration), and times to interventions; χ
2
analysis was used for categorical variables, t-testing for continuous variables.

Results: 706/10947 (6.4%) of pediatric CPA events and 18473/189,653 (9.7%) of adult CPA events occurred in the ED. Median age for adults was 65 yr (IQR 52 - 77 yr), 21 months for children (IQR 3 mos - 10 yr). Children had a greater prevalence of respiratory insufficiency (51% vs. 43%, p<0.001), septicemia (10% vs. 7%, p=0.05), and trauma (18% vs. 6%, p<0.001). Shockable initial rhythm was less common in children (17% vs. 31%, p<0.001) and CPR prior to pulselessness was more common (28% vs. 8%, p<0.001). In children, total duration of CPR was longer (28.6 + 1.0 mins vs. 22.9 + 0.3 mins, p<0.001) and time to epinephrine was shorter (2.2 + 0.4 mins vs. 2.8 + 0.1 mins, p=0.03). Times to compressions, airway, and defibrillation did not differ significantly. 24 hour survival was worse among children (26% vs. 33%, p=0.001); ROSC (49% vs. 52%) and survival to discharge (26% vs. 24%) did not differ significantly.

Conclusions: Compared with adults, 24 hour survival is worse among children with CPA in the ED; other outcomes are less discrepant than in previously published studies. Pediatric CPA in the ED more commonly occurs from respiratory insufficiency or shock. Differences in outcomes do not appear related to timing of critical interventions.
Abstract 251: First-Year Medical Students Acquire Contextually Relevant Cardiopulmonary Resuscitation Knowledge When Exposed to an In-Hospital Focused BLS Course Versus a Traditional Healthcare Provider BLS Course: A Prospective, Randomized, Controlled Evaluation
Authors: Duval-Arnould Jordan M , Perretta Julianne , Chime Nnenna , Hollingsworth Merona , Aksamit Deborah , Twilley Ida-Marguerite M , Luksic Mary Ann , Jung Julianna , Nelson-McMillan Kristen , Shilkofski Nicole A , Hunt Elizabeth
Published: April 2024

INTRODUCTION: The traditional AHA Healthcare Provider BLS course focuses on out-of-hospital cardiac arrests as the contextual environment and does not provide content focused on optimizing quality of BLS for in-hospital cardiac arrests (IHCA).

METHODS: First year medical students participated in a prospective, randomized, controlled evaluation of a traditional AHA Healthcare Provider BLS course “TradBLS” vs. a modified course including objectives focused on managing IHCA, “HospBLS”. The courses were identical in length, taught by the same instructors, and used AHA materials. Students completed a Multiple Choice Question (MCQ) survey evaluating knowledge regarding CPR performance and leadership. This project was approved by our Institutional Ethics Committee as an Educational Quality Assurance evaluation and by the AHA.

RESULTS: 122 students completed an MCQ survey. Both groups had similar previous BLS certification [HospBLS 29/62 (47%) vs. TradBLS: 32/60 (53%) p = 0.469], and lack of advanced training (neither ACLS or PALS) [95% vs. 97% p = 0.675]. The HospBLS group was significantly more likely to identify a set of six maneuvers to improve quality of in-hospital CPR [87% vs. 27%, p<0.001]. The HospBLS group was more likely to identify 2-person bag-mask-ventilation (BMV) as a maneuver to try when unable to move the chest [77% vs. 18%, p<0.001] as well as correct O2 delivery when performing BMV [90% vs. 17%, p< 0.001]. An equivalent number of students in each group reported they could either lead until the code team arrives [52% vs. 58%, p=0.46] or could lead a simulation but not a real life scenario [5% vs. 10%, p = 0.28]. However, the HospBLS group was much more likely to identify themselves as qualified to be a team leader [44% vs. (3%), p<0.001]; and much less likely to indicate they were not qualified to be a team leader” [0% vs. 28%, p<0.001].

CONCLUSIONS: Medical students that took the HospBLS curriculum were more likely to identify maneuvers to optimize quality of CPR for the IHCA, and expressed greater confidence in their ability to be a team leader. This evaluation suggests that knowledge on optimizing CPR for IHCA can be effectively acquired with the same time and resource utilization of the standard AHA Healthcare Provider course and should be further evaluated.
Abstract 278: A Pilot Study Examining the Role of Regional Cerebral Oxygen Saturation Monitoring as a Marker of Return of Spontaneous Circulation in the Shockable and Nonshockable Causes of Cardiac Arrest
Authors: Ahn Anna , Nasir Asad , Dorazi Francis , Malik Hanan , Parnia Sam
Published: April 2024

Background: To date there has been no reliable “real time” monitoring available to determine the adequacy of oxygen delivery and cerebral perfusion during cardiac arrest. Although, we have previously demonstrated that the mean regional cerebral oxygen saturation (rSO2) measured by cerebral oximetry can be used to determine return of spontaneous circulation in cardiac arrest, the rSO2 level that corresponds with ROSC in the 3 main different subtypes of cardiac arrest (VF/VT, PEA, asystole has not been examined.

Objectives: To investigate the level of rSO2 that corresponds with ROSC in 1) VF/VT, 2) PEA and 3) asystole subtypes of cardiac arrest using a commercially available cerebral oximeter (Equanox, Nonin, USA)

Methods: Cerebral oximetry was applied to 34 in-hospital cardiac arrest patients and continuous data was collected until either ROSC was achieved or CPR was terminated.

Results: Overall 20 patients achieved ROSC, whereas 14 did not. There was a significant overall difference in mean±SD rSO2% in patients who achieved ROSC (49.7 ± 11.3% vs. 33.9 ± 15.0% p=<0.001) compared to those who did not. Examination of the cardiac arrest subtypes revealed that while this difference was observed in the PEA (n=13) 54.6 ± 8.7 vs. 36.8 ± 20.4 (p=<0.05) and asystole (n=16) 46.6 ± 11.4 vs. 27.4 ± 10.8 (p=<0.05) subgroups, there was no difference in rSO2 in patients with and without ROSC in the VF/VT subgroup (n=5) 41.6 ± 18.5 vs. 45.0 ± 11.6 (p=0.8).

Conclusions
: Although cerebral oximetry may be used as a real-time non-invasive marker of ROSC during cardiac arrest, the main difference in rSO2 between patients achieving ROSC and those without ROSC applies to the asystole and PEA sub groups of cardiac arrest, rather than VF/VT. This likely reflects the different dominant physiological disorders between shockable and non-shockable causes of cardiac arrest. Whereas recovery from PEA and asystole is dependent on the adequacy of oxygen delivery, recovery from VF/VT predominantly relates to the timing of defibrillation.
Abstract 28: Administration of Intravenous Ascorbic Acid Following Return of Spontaneous Circulation, with and Without Hypothermia, Improved Both Myocardial Dysfunction and Survival from Ventricular Fibrillation Cardiac Arrest
Authors: Tsai Min-Shan , Huang Chien-Hua , Tsai Chia-Ying , Hsu Chiung-Yuan , Chang Wei-Tien , Chen Wen-Jone
Published: April 2024

Background
Our previous studies disclosed intravenous administration of ascorbic acid (AA) during CPR facilitates resuscitation and improves outcomes in VF cardiac arrest. However, the effect of AA administrated after ROSC and the interaction with hypothermia has not been clarified.

Hypothesis
Intravenous administration of AA after ROSC, with and without hypothermia, both can improve myocardial dysfunction and survival in VF cardiac arrest.

Methods
The animals were equally randomized to AA, hypothermia, AA+hypothermia and control groups. VF was induced and untreated for 5 minutes, followed by 1 minutes of CPR, and then one electrical shock of 5 J. After ROSC, the AA and AA+hypothermia group received intravenous administration of AA (100 mg/kg), and the hypothermia and control group received saline as placebo. In the hypothermia and AA+hypothermia groups, therapeutic hypothermia of 32°C was applied for 2 hours following ROSC. Malondialdehyde(MDA) of myocardium was assessed to determine oxidative stress.

Results
Within the first 2 hours, the control and the AA groups had higher heart rates than the hypothermia and AA+hypothermia groups. At the 4
th
hour, the AA, hypothermia and AA+hypothermia groups had significant lower MDA concentration than the control group (
p
<0.05). The AA, hypothermia and AA+hypothermia groups had better dp/dt
40
and -dp/dt
max
than the control group, within 4 hours following ROSC (Table 1). Histological exam showed less myocytolysis in the AA, hypothermia and AA+hypothermia groups than in the control group. The AA, hypothermia and AA+hypothermia groups had better survival than the control group (
p
<0.05), but there was no difference between the AA, hypothermia and AA+hypothermia groups.

Conclusion
Intravenous administration of AA after ROSC, with and without hypothermia, both may improve myocardial dysfunction and survival in VF cardiac arrest.
Abstract 284: The Relation Between Serum Procalcitonin and Perfusion Parameters After the Return of Spontaneous Circulation Following Out-of-Hospital Cardiac Arrest
Authors: Sato Koji , Taniguchi Takumi
Published: April 2024

Procalcitonin (PCT) has been broadly used as an infectious biomarker. However we often found that the patients without infection showed high level of PCT. In past research, PCT has been reported to be a useful biomarker in predicting neurological outcome after the return of spontaneous circulation (ROSC) following out-of-hospital cardiac arrest (OHCA).

Our hypothesis is that the level of PCT in the patients after ROSC following OHCA may relate to time from cardiac arrest and reflect tissue hypoxia. Moreover it may predict outcome. This study was aimed to evaluate relation between the serum level of PCT and perfusion parameters in OHCA patients.

Twenty sequential patients who admitted to the ICU after ROSC following OHCA were included. Infectious patients, trauma patients and extracorporeal CPR patients were excluded. This study was a retrospective, single-center analysis, conducted in the ICU of the university hospital. We evaluated the maximum PCT level within 48hr after admission, cardio-pulmonary arrest time, serum lactate level at admission, Glasgow outcome scale at 28 day.

Twelve of twenty patients were cardiogenic patients. Average ROSC time from OHCA was 27±17 minutes. The maximum PCT was significantly higher in patients who died in the hospital (2.2±2.6 V.S 15.3±17 ng/mL, p=0.01). We defined Glasgow outcome scale 4-5 as favorable outcomes and eight patients showed favorable outcomes. Serum PCT in patients with favorable outcomes was lower than that of unfavorable outcomes, but there was no statistical significance (1.2±2.5 V.S 9.4±13.5 ng/mL). The maximum PCT significantly correlated with serum lactate at admission (r=0.63, p<0.01), and ROSC time from OHCA (r=0.54, p=0.01). In conclusion, the maximum PCT after cardiac arrest did not predict neurological outcome. But PCT correlated with degree of tissue hypoxia. The serum PCT may reflect ischemia-reperfusion injury.
Abstract 292: Comparison of Pharmacological and Physical Hypothermia in Cerebral and Myocardial Function in a Porcine Model of Cardiac Arrest and Resuscitation
Authors: Weng Yinlun , Sun Shijie , Chen Wei , Wu Xiaobo , Xu Jiefeng , Tang Wanchun
Published: April 2024

Objective: Non-selective cannabinoid (CB) 1/2 receptor agonist, WIN 55,212-2, has been demonstrated to produce pharmacological hypothermia and improved outcomes of CPR in a rat model. In this study, we compared the effects of pharmacological hypothermia induced by WIN 55,212-2 and physical hypothermia by surface cooling in myocardial and neurological function in a porcine model of CPR.

Hypothesis: Pharmacological hypothermia by WIN 55,212-2 produced the similar or better cerebral and myocardial function as surface cooling.

Methods and results:Ventricular fibrillation (VF) was induced in 14 male domestic pigs weighing between 35 ± 2 kg. CPR was initiated after 7 min of untreated VF. Defibrillation was attempted after 5 min of CPR. If ROSC was not achieved, two mins of CPR was continued and sequenced with defibrillation attempt until ROSC or for a total of 15 mins. At 5 min post resuscitation, animals are randomized to receive intravenous infusion with WIN 55,212-2 at a dose of 1.0 mg/kg/h or surface cooling until blood temperature cooled down to 34 celcius degree and maintained for 4 hrs. When compared to the animals treated with surface cooling, significantly improvement in neurological alertness score (NAS) was observed in the WIN 55,212-2 treated animals at 24 and 48 hrs, but not at 72 hrs (WIN 55,212-2 vs surface cooling: 24 hrs, 93 ± 5 vs 77 ± 12, p<0.01; 48 hrs, 100 ± 0 vs 93 ± 6, p=0.01) (Figure 1A). As to the post resuscitation myocardial function, there was no significant difference in ejection fraction (EF) between these two groups (Figure 1B).

Conclusions: Pharmacological hypothermia induced by WIN 55,212-2 exerted better post resuscitation short-term neurological function than physical hypothermia with the similar post resuscitation myocardial function.
Abstract 294: The Effect of 1-Shock Protocol using Biphasic Defibrillators for Treatment of Out-of-Hospital Shockable Cardiac Arrest
Authors: Yagi Tsukasa , Nagao Ken , Tachibana Eizo , Nishikawa Kei , Yonemoto Naohiro , Shirai Shinichi , Takayama Morimasa , Nonogi Hiroshi , Kimura Takeshi ,   The JCS-ReSS Group
Published: April 2024

BACKGROUND
In recent guidelines for electrical therapy of cardiopulmonary resuscitation (CPR), there was insufficient evidence to recommend any specific biphasic waveform. When defibrillation is required, a single shock should be provided with immediate resumption of chest compressions after the shock (1-shock protocol). We investigated the effect of 1-shock protocol using biphasic defibrillators.

METHODS
From the data of the All-Japan Utstein Registry, a prospective, nationwide, population-based registry of out-of-hospital cardiac arrest, we extracted the patients who were persons 18 years of age or older with bystander-witnessed shockable cardiac arrest due to cardiac etiology in the years 2005 (the 3-shock protocol era), and 2008, 2009 and 2010 (the 1-shock protocol era). The study patients were divided into 4 groups according to the two shock protocols and the two AED waveforms. The primary endpoint was 30-day favorable neurological outcome after shockable arrest.

RESULTS
Of the 17,297 patients who met the inclusion criteria, 1,626 received 3-shock protocol using biphasic AEDs, 1,960 3-shock protocol using monophasic AEDs, 12,133 1-shock protocol using biphasic AEDs, and 1,578 1-shock protocol using monophasic AEDs. Figure showed comparisons of favorable neurological outcome between the 1-shock protocol and the 3-shock protocol groups, and between the biphasic AEDs and the monophasic AEDs groups. In the subgroups of patients who did not receive bystander CPR, the frequencies were similar to the results of all patients. Adjusted odds ratios for favorable neurological outcome were 2.5 (95% CI, 2.2 to 2.8) after 1-shock protocol and 1.3 (95% CI, 1.2 to 1.4) after biphasic AEDs in the whole cohort.

CONCLUSION
Single-shock protocol using biphasic AEDs was superior to the others, including 1-shock protocol using monophasic AEDs, 3-shock protocol using biphasic AEDs and 3-shock protocol using monophasic AEDs, in terms of neurological benefits.
Abstract 296: Determinants of Incidence of Ventricular Fibrillation as First Recorded Rhythm During Out-of-Hospital Cardiac Arrest and Association with Long-Term Neurological Outcomes: Observations from a Large Randomized Clinical Study
Authors: Yannopoulos Demetris , Holcomb Richard , Frascone Ralph J , Mahoney Brian D , Wayne Marvin A , Swor Robert A , Domeier Robert M , Olinger Michael L , Tupper David E , Aufderheide Tom P
Published: April 2024

Background: We sought to identify the factors that were associated with higher incidence of VF and survival with good neurological function in the ResQ Trial patients that compared standard cardiopulmonary resuscitation (S-CPR) versus active compression decompression CPR with an inspiratory impedance threshold device (ACD+ITD) in patients with out of hospital cardiac arrest (OHCA).

Methods: A retrospective analysis of a randomized multicenter clinical study of 1655 patients with OHCA. 88.3% (106/120) of the patients discharged with good neurological function [Modified Rankin Score (MRS)≤3] had a first recorded rhythm of ventricular fibrillation/pulseless ventricular tachycardia (VF). The first rhythm was recorded in 99.4% (1645/1655) of the cases about 9.5 minutes after 911 call, on average 3 minutes after the arrival of EMS on the scene and after CPR was performed for at least 2 minutes.

Results: A total of 32.8% of the patients had VF as presenting rhythm and 42.8% received bystander CPR. Presence of bystander CPR was associated with a higher VF incidence only in the S-CPR group (40.8% versus 23.1% with no bystander, p=0.001) but survival was 7.6% versus 4.6% p=0.09. Presence or absence of bystander CPR let to similar VF incidence and survival in the ACD+ITD group 36.1% versus 33.9% and 9.0% versus 8.9% respectively, p>0.2. After propensity adjustment for witnessed arrest, age <67, gender, public location, bystander CPR lost significance. In the absence of bystander CPR, ACD+ITD significantly increased the incidence of first recorded VF compared to S-CPR from 106/459 (23.1%) to 164/484 (33.9%) [OR 1.71, 95% CI (1.27, 2.30), p<0.001], and in patients with VF, return of spontaneous circulation increased from 65/459 (14.2%) to 104/484 (21.5%) [OR 1.66, 95% CI (1.16, 2.37), p=0.004], leading to an overall doubling of survival with MRS≤3 from 21/455 (4.6%) to 43/482 (8.9%) [OR 2.02, 95% CI (1.15, 3.65), p=0.009]. After propensity adjustment ACD+ITD remained a significant predictor of an MRS≤3, (p= 0.02).

Conclusions: VF was the most important predictor of survival with MRS≤3.

In the absence of bystander CPR, ACD+ITD increased VF incidence as the first recorded rhythm and doubled survival to hospital discharge with MRS≤3 compared to S-CPR.
Abstract 303: End-Tidal CO2 Reactivity Is Associated with Defibrillation Success
Authors: Husa Ruchika D , Bowers Owen , Sell Rebecca , Scyoc Dorothy , Minokadeh Anush , Davis Daniel
Published: April 2024

Background: High quality cardiopulmonary resuscitation (CPR) appears to modulate ventricular fibrillation (VF) morphology and increase defibrillation success. However, VF waveform analysis has not proven to be clinically effective in guiding resuscitation. End-tidal CO2 (PetCO2) correlates well with cardiac perfusion during CPR.

Objective: To evaluate PetCO2 as a predictor of defibrillation success.

Methods: This was a prospective, observational study conducted at two urban academic hospitals with a combined total of 500 beds. Data regarding defibrillation attempts, CPR process, and PetCO2 were abstracted from monitor/defibrillators. All arrest victims with primary VF or ventricular tachycardia (VT) for whom CPR and PetCO2 data were available were included in this analysis. Patients with return of spontaneous circulation (ROSC) were compared to those without ROSC with regard to the change in PetCO2, mean and final compression rate and depth, and chest compression fraction (CCF).

Results: A total of 32 patients were included in this analysis; 19 of these (59%) had ROSC. PetCO2 values prior to the final defibrillation attempt were 121% higher than initial PetCO2 values in patients with ROSC versus only 19% higher in patients without ROSC (p<0.01). Patients with and without ROSC were similar with regard to mean compression depth (2.5 vs. 2.7 inches, p=NS), final compression depth (2.7 vs. 2.8 inches, p=NS), mean compression rate (119/min for both, p=NS), final compression rate (121/min vs. 123/min, p=NS), mean CCF (83% vs. 85%, p=NS), and final CCF (83% vs. 91%).

Conclusions: An increase in PetCO2 was associated with ROSC among inpatients with VF/VT arrest. No differences with regard to overall or final CPR process measures were observed. The “PetCO2 responsiveness” to CPR may reflect an underlying physiology that predicts defibrillation success.
Abstract 306: Impact of First Medical Contact on Symptom Onset to Door Time in Patients Presenting for Primary Percutaneous Coronary Intervention
Authors: Hafiz Abdul Moiz , Naidu Srihari S , DeLeon Joshua , Islam Shahidul , Alkhatib Basil , Lorenz Miguel , D’Elia Alexis , Rosenthal Barry , Marzo Kevin P
Published: April 2024

Background:
Shorter pre-hospital delays in ST-elevation myocardial infarction (STEMI) are associated with improved outcomes. Whether first medical contact type is related to symptom onset to door time (SODT) remains unknown.

Methods
: We performed a retrospective chart review of all consecutive patients treated with primary percutaneous coronary intervention (PCI) for STEMI at our tertiary care suburban teaching hospital from October 1, 2005 to December 31, 2009. We compared SODT in patients whose first medical contact was a private physician, in person or via telephone; and patients who presented to the Emergency Department (ED) directly, in person or via Emergency Medical Services (EMS).

Results
: Of 366 patients (table), 84 (23%) contacted a physician (group A) while 282 (77.6%) did not (group B). Group A was associated with higher median SODT (239.5 vs. 130 minutes, p=0.0043) and a trend to higher mortality at a median follow-up of 3.85 years (17.86% vs. 10.64%, p=0.089). Multiple linear regression analysis revealed two factors to be independently associated with prolonged SODT: 1) first contact (physician vs. no physician), p=0.002, regression coefficient=0.547, standard error (SE)=0.171, indicating a 73% increase in SODT if patients first contacted physicians and 2) mode of transportation (EMS vs. personal), p=0.016, regression coefficient=0.349, SE=0.144, indicating a 30% decrease in SODT if EMS was used. Patients presenting during “on-hours” (weekdays) were more likely to first contact a physician compared with those presenting during “off-hours” (weeknights and weekends) (66.67% in group A vs. 45.04% in group B, p<0.001).

Conclusions
: Patients whose first medical contact was a physician had greater pre-hospital delays compared to those who sought emergent medical care directly, and a trend to higher mortality. This pattern occurred more often during “on-hours”. Educational efforts aimed at both patient and physician office practices are warranted.