bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 18051: High Prevalence of Active Myocarditis in Patients with Takotsubo Cardiomyopathy: A Magnetic Resonance-endomyocardial Biopsy Study
Authors: Pieroni Maurizio , Smaldone Costantino , Camporeale Antonia , Severino Anna , Ventrone Antonella , Macchione Andrea , Bellocci Fulvio , Crea Filippo
Published: April 2024

Background:
Tako-tsubo cardiomyopathy (TTC) was recently classified as a cardiomyopathy with distinct clinical and angiographic features, but mechanisms of cardiac dysfunction and histological substrate are still largely unclear. We evaluated cardiac magnetic resonance (CMR) and endomyocardial biopsy (EMB) findings in patients with TTC.

Methods:
Twenty consecutive patients (19 F, 58±12 years) with clinical and angiographic features of TTC underwent CMR with edema (STIR images) and delayed enhancement (DE) studies. Of these, 15 patients also underwent EMB. Myocardial samples obtained from apical akinetic left ventricular segments were processed for histology, immunohistochemistry and polymerase chain reaction (PCR) for cardiotropic viruses.

Results:
All patients presented acute chest pain with ST-segment elevation in anterior leads and evidence of myocardial necrosis. Symptoms were precipitated by emotional stress in 12 (60%) cases. At CMR DE was observed in 11 patients (55%) in all cases with a subepicardial or midventricular pattern; edema was observed in 10 (50%) patients, associated with DE in 8 cases. Neither DE nor edema was observed in 7 patients. In 11 patients (73%) EMB showed an active lymphocytic myocarditis with evidence of activated T lymphocytes. In 4 patients (27%) contraction band necrosis was observed. PCR identified parvovirus B19 viral genome in 3 patients with myocarditis. Among patients with a histological diagnosis of myocarditis CMR showed DE in 10 and edema in 8 cases. One patient with myocarditis had neither DE nor edema at CMR. Patients with contraction-band necrosis showed no DE or edema at CMR. Three myocarditis virus-negative patients failing to recovery after 6 weeks from clinical presentation, received prednisone and azathioprine for 8 weeks with significant improvement of left ventricular contractility.

Conclusions:
Acute myocarditis represents a frequent substrate of TTC. CMR may help to identify myocardial inflammation in TTC patients. Immunohistochemical and virological diagnosis through EMB may affect both treatment and prognosis. Further studies are needed to clarify the prevalence of acute myocarditis among TTC patients and the possible association between emotional stress and viral infection.
Abstract 18079: Among CHD Patients in the IDEAL Study, Those with Elevated Levels of Alanine Aminotransferase at Baseline Had a Lower Rate of Major Coronary Events
Authors: Tikkanen Matti J , Fayyad Rana , Laskey Rachel , Holme Ingar , Faergeman Ole , Olsson Anders G , Lindahl Christina , Kastelein John J , Lytken Larsen Mogens , Pedersen Terje R ,   On Behalf of the IDEAL Investigators
Published: April 2024

Background:
Previous evidence suggests that statin therapy can reduce cardiovascular (CV) morbidity in patients with mild-to-moderately abnormal liver tests. In this post hoc analysis of the IDEAL study, we investigated the relationship of elevated baseline levels of the liver enzyme alanine aminotransferase (ALT) on CV events, and compared the effects of atorvastatin (ATV) 80 mg versus simvastatin (SIM) 20-40 mg in patients with normal and elevated baseline ALT levels.

Methods:
IDEAL was a large randomized trial comparing ATV 80 mg with SIM 20-40 mg in 8888 patients with CHD over 4.8 years of follow-up. Cox regression analysis was performed to investigate the relationship of normal levels of ALT (defined as baseline ALT <ULN [upper limit of normal]; 87.8% of subjects) vs elevated ALT (baseline ALT ≥ULN; 11.5% of subjects had ALT ≥ULN-<2 ULN and 0.74% had ALT ≥2 ULN-<3 ULN) on the risk of major coronary events (MCE: CHD death, non-fatal MI or resuscitated cardiac arrest). In addition, treatment effect (ATV 80mg vs SIM 20-40 mg) was examined for subjects with normal and elevated ALT at baseline.

Results:
Over the course of the study, mean ALT levels increased among patients with normal baseline ALT (n=7782) and decreased for those with ALT ≥ULN at baseline (n=1081). Overall, those patients with normal ALT levels at baseline experienced significantly more MCE than patients with higher baseline ALT levels (≥ULN) (HR=0.76; 95% CI 0.61, 0.96; p=0.02). This finding was consistent in patients treated with ATV (HR=0.60; 95% CI 0.42, 0.87; p=0.007) but not those receiving SIM (p=0.464). In patients with elevated ALT baseline levels, ATV significantly reduced the risk of MCE compared with SIM (HR=0.62; 95% CI 0.40, 0.96; p=0.03), but in patients with normal baseline ALT the difference between treatment groups did not reach statistical significance.

Conclusions:
In the overall population of CHD patients treated with ATV or SIM, those with normal baseline ALT levels experienced significantly more MCE than those with baseline ALT ≥ULN. The clinical benefits of intensive lipid lowering with ATV compared with a more moderate regimen with SIM were generally greater in patients with abnormal liver tests than in patients with normal liver tests.
Abstract 18114: Efficacy of Apolipoprotein A-IV as a Vascular Anti-Inflammatory and Anti-Oxidant Agent
Authors: Shearston Kate D , Barter Philip , Yan Ling , Rye Kerry-Anne
Published: April 2024

Objective:
Apolipoprotein (apo) A-IV, the 3rd most abundant HDL apolipoprotein in human plasma, has anti-inflammatory properties in animal models of colitis and LPS-induced systemic inflammation. This study investigates the ability of apoA-IV to inhibit acute vascular inflammation in the NZW rabbit.

Methods:
A non-occlusive peri-arterial carotid collar was inserted into normocholesterolemic NZW rabbits (mean weight 3 Kg) 24 h after administering a single intravenous (iv) infusion of either saline or lipid-free apoA-IV (1 mg/kg). The animals were sacrificed 24 h post-collar insertion. Carotid arteries were extracted and analysed immunohistochemically for endothelial expression of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and intima/media neutrophil infiltration (CD18+ cells). Human coronary artery endothelial cells (HCAECs) were pre-incubated for 16 h with discoidal reconstituted HDL (rHDL) containing phosphatidylcholine complexed with apoA-IV (final apoA-IV concentration 10 µM/L), then stimulated for a further 5 h with tumour necrosis factor α (TNF- α) (0.2 ng/ml). Cell surface VCAM-1 and ICAM-1 expression was measured by flow cytometry. VCAM-1 and ICAM-1 mRNA levels and the mRNA level of the anti-oxidant and anti-apoptotic enzyme 3β-hydroxysteroid-D24 reductase (DHCR24) were quantified by qPCR.

Results:
Relative to the saline-infused animals, a single iv infusion of lipid-free apoA-IV decreased collar-induced neutrophil infiltration by 74% and endothelial expression of ICAM-1 and VCAM-1 by 75% and 68%, respectively. Pre-incubation of TNF-α stimulated HCAECs with rHDL reduced ICAM-1 protein and mRNA levels by 34% and 48%, respectively. VCAM-1 protein and mRNA levels were decreased by 61% and 55%, respectively. Pre-incubation of HCAECs with rHDL increased DHCR24 mRNA levels 2.6-fold.

Conclusion:
ApoA-IV has potent vascular anti-inflammatory and anti-oxidant properties
in vitro
and
in vivo
.
Abstract 18131: Increased Cardiomyocyte Stiffness in Cardio-Renal Disease
Authors: Hamdani Nazha , Szymanski M K , Schoemaker Regien G , van der Velden Jolanda
Published: April 2024

Cardio-renal disease has been associated with diastolic rather than systolic cardiac dysfunction. As diastolic dysfunction cannot be attributed to adverse remodelling, the present study investigated if intrinsic cardiomyocyte stiffness is a determinant of diastolic dysfunction in cardio-renal disease. Thereto, cardiomyocyte function was studied in rats with cardio-renal disease, which was induced by myocardial infarction in rats with chronic renal dysfunction (Munich Wistar Fromter; RD+CD). This group was compared to rats with solely cardiac disease (CD; age-matched Wistar rats), solely renal disease (RD) and healthy rats (Ctrl). Twelve weeks after surgery force was measured in left ventricular Triton-permeabilized cardiomyocytes at different calcium concentrations to assess myofilament function. Maximal force did not differ among groups. In contrast, myocardial infarction significantly increased passive force (CD vs Ctrl; figure), which was even more pronounced in rats with renal dysfunction (RD+CD vs RD; figure). No change in myofilament Ca
2+
-sensitivity was observed in the CD group, whereas Ca
2+
-sensitivity of force was significantly reduced in RD+CD compared to Ctrl. The changes in passive force and Ca
2+
-sensitivity could not be corrected by protein kinase A, which mimics beta-adrenergic stimulation. In contrast, a 2-times increase in expression and activity of protein kinase C (PKC) alpha was found in RD+CD myocardium (Figure). In conclusion, diastolic dysfunction in cardio-renal disease may be partly attributed to increased intrinsic cardiomyocyte stiffness, rather than to adverse remodelling. The increase in cardiomyocyte stiffness may result from increase PKCalpha-mediated phosphorylation of titin, and could represent a target for treatment of diastolic dysfunction in cardio-renal disease.
Abstract 18240: Wnt Signaling Negatively Regulates the Proliferation of Adult Cardiac Progenitor Cells
Authors: Oikonomopoulos Angelos , Sereti Konstantina-Ioanna , Conyers Frank , Bauer Michael , Liao Annette , Guan Jian , Han Jung-Kyu , Dong Hanhua , Bayomy Ahmad , Fine Gabriel C. , Westerman Karen , Biechele Travis L. , Moon Randall T. , Force Thomas , Liao Ronglih
Published: April 2024

Recent studies have demonstrated the existence of endogenous cardiac stem/progenitor cells capable of regenerating damaged myocardium following myocardial infarction (MI). Cardiac side population (CSP) cells are cardiac precursors found in the adult myocardium, which are able to differentiate into functional cardiomyocytes both in vitro and in vivo, following MI. In response to local tissue injury, CSP cells are maintained through a process of self-renewal. The molecular signals that control the self-renewal of adult progenitor cells in the heart remain unclear. Canonical Wnt signaling pathway has been implicated in the regulation of tumor progression, development and regeneration in various tissues. The goal of this study was to determine the effects of Wnt signaling pathway on the homeostasis of adult CSP cells under normal and disease conditions.

Results:
In contrast to previous work in embryonic or early post-natal cardiac stem cells, we reveal that Wnt signaling negatively regulates adult CSP progenitor cell proliferation, both in vitro and in vivo through suppression of cell cycle progression. Furthermore, we demonstrate that Wnt signaling exerts its anti-proliferative effect through the activation of insulin-like growth factor binding protein 3 (IGFBP3). Administration of recombinant Wnt3a protein in the infarct/border zone of mouse hearts, following MI decreases the amount of cardiac CSP cells and impairs the endogenous cardiac regenerative capacity, as evidenced by the decreased number of BrdU positive cardiomyocytes. Reduction of cardiac regenerative capacity mediates adverse effects on post-MI remodeling and performance.

Conclusion:
Our data demonstrate that Wnt signaling represents an effective negative regulator of adult cardiac progenitor cell proliferation, under physiologic conditions and post-MI. Inhibition of Wnt signaling may be considered as an approach to promote cardiac regeneration following ischemic injury.
Abstract 18309: Wireless Electrocardiographic Transmission with
e
-Activation of PCI Team and Reconstructed System of Care Shortens Door-to-Balloon Time in Acute Myocardial Infarction
Authors: Chang Wei-Tien , Lee Chee-Ming , Chen Li-Chin , Wang Chih-Hung , Lee Chiao-Hao , Yang Bey-Jing , Yang Li-Fen , Tseng Chuen-Den , Lin Jiunn-Lee , Chen Shyr-Chyr , Hung Kuan-Yu , Chen Ming-Fong
Published: April 2024

Background:
Early reperfusion of the occluded coronary artery is the first priority in the treatment of acute ST-elevation myocardial infarction (STEMI). Time to primary percutaneous coronary intervention (PCI) can be shortened by improved system of care. Electronic transmission of electrocardiogram (ECG) to cardiologist's cell phone enables earlier activation of the PCI team. We therefore sought to improve the door-to-balloon (DTB) time by
e
-technologies and reorganized system of care.

Methods:
An ECG system capable of wireless cell phone transmission and
e
-activation of PCI team (Fig 1A) was introduced to a university medical center in Dec., 2009. The processing of STEMI patients was also reorganized, including performance of ECG at the triage of emergency room (ER) with immediate physician's confirmation,
e
-transmission of ECG to cardiologist's cell phone with
e
-activation of the PCI team, standardized ER treatment with prompt transportation to catheterization lab, packaged PCI instruments, and integrated care at the catheterization room. The door-to-ECG (DTE), door-to-door (DTD) and DTB times of STEMI were recorded. The achievement rate of DTE < 10 min, DTD < 60 min and DTB < 90 min were also analyzed. Comparison was made between 2009 and 2010.

Results:
Sixty one STEMI patients eligible for PCI in 2009 and 62 in 2010 were included. After implementation of the above system, the rate of DTE < 10 min was increased from 55.7% in 2009 to 90.3% in 2010 (
P
< 0.001). The rate of DTD < 60 min was raised from 50.8% to 85.5% (
P
< 0.001), and rate of DTB < 90 min raised from 65.6% to 88.7% (
P
< 0.01). The average DTE, DTD and DTB times were also significantly shortened (all
P
< 0.001, Fig 1B).

Conclusion:
Electronic ECG transmission to cell phone enables early notification of STEMI and rapid activation of PCI team. Combined with reconstructed in-hospital system of care, these altogether lead to shortened DTE, DTD and DTB times, better compliance with the guidelines and improved quality of care.
Abstract 18432: Global Transcriptional Profiling of Monocytes and Macrophages and Association with Coronary Artery Disease Risk Factors in a Large Multi-Center Collaborative Study: The Cardiogenics Transcriptomic Study
Authors: Maouche Seraya ,   Cardiogenics Consortium, Hengstenberg Christian , Samani Nilesh J , Ouwehand Willem H , Cambien Francois , Goodall Alison H , Schunkert Heribert
Published: April 2024

Objective:
Global transcriptional profile of cells involved in the pathogenesis of coronary artery disease (CAD) is poorly characterized. We thus aimed to identify biological processes and transcription factors (TFs) accompanying the transition of monocytes to macrophages as well as expression patterns associated to CAD risk factors.

Methods:
Within Cardiogenics Consortium, we recruited 459 CAD patients and 458 healthy subjects. Most CAD patients had a validated MI within the previous 3-36 months and were aged between 40 and 65 years. Healthy subjects were all blood donors (42% male), without history of CAD. 1,533 RNA samples (849 monocytes and 684 macrophages) from the 917 subjects were analyzed on the Illumina Ref-8 v3.0 arrays.

Results:
Monocyte to macrophages differentiation process involves massive changes in gene expression with 4.181 genes being significantly (P<10-3) modulated. Overall, this process is characterized by repression of large numbers of genes involved in the immune response and over-expression of genes of the lipid metabolism. Specifically, multiple genes expressed only in macrophages are involved in cholesterol metabolism such as APOE, PLAU, A2M, and SPP1. We found 155 TFs being significantly modulated between monocytes and macrophages. Among which 84.5% were down-regulated in macrophages. We found 28 and 14 genes being associated with gender in monocyte and macrophages, respectively. In monocytes, the expression of 21 genes was associated with BMI, including genes involved in cholesterol, steroid and lipid metabolic processes such as ABCG1, YWHAH, SARD5A1, and SORT1, and genes involved in obesity such as ADRB2 and GPX3. Only two genes, NEFH and AGPAT4 were found to be associated with age in monocytes.

Conclusions:
We provide the first comprehensive large-scale analyses of monocyte and macrophage transcriptomes. The finding that multiple genes of the lipid system were over-expressed in macrophages is not only concordant with the fact that these cells are essential modulators of lipid metabolism but shows that macrophages express lipid handling genes even in the absence of exposure to exogenous lipids. Our results might be used to interpret GWAS finding and shed light on the role of monocyte and macrophage cells in CAD.
Abstract 195: Impairment of Carotid Artery Blood Flow by Supraglottic Airway Use in a Swine Model of Cardiac Arrest
Authors: Segal Nicolas , Yannopoulos Demetris , Mahoney Brian D , Frascone Ralph J , Cowles Colin G , McKnite Scott H , Chase David G
Published: April 2024

Objective:
Supraglottic airway devices (SGDs) can be inserted ‘blindly’ without stopping compressions during cardiopulmonary resuscitation (CPR) and are therefore often used instead of endotracheal tubes (ETT). These devices utilize pressurized balloons to direct air to the trachea and prevent esophagus insufflation. We hypothesize that the use of a SGD will compress the carotid artery and decrease carotid blood flow (CBF) during CPR.

Methods:
Ventricular fibrillation was induced in 9 female pigs (32±1Kg) anesthetized with isoflurane. Four minutes later CPR was then performed continuously for 3 six-minute epochs. During each epoch, an ETT was used for the first 3 minutes, followed by 3 minutes of each SGD (King LTS-D, LMA Flexible, or Combitube in a random order. The primary endpoint was mean CBF (ml/min). Statistical comparisons among the 4 airway devices were performed by Wilcoxon Rank test. Post mortem carotid arteriograms were obtained.

Results:
CBF (mean ml/minute ± SD) was significantly lower with each SGD [King (168 ± 42), LMA (106 ± 89), and Combitube (99 ± 128)] versus ETT (209 ± 134) (p<0.05 for each SGD compared with ETT; figure). Arteriograms showed that each SGD compressed the internal and external carotid vessels.

Conclusion:
The use of 3 different SGDs during CPR significantly decreased CBF in a porcine cardiac arrest model. While these data are limited to pigs, they may impact clinical decision making. Figure: real time tracing during 1 experiment. Pink: Carotid blood flow (CBF); Blue: Thoracic aortic pressure (AO pressure); Green: Airway pressure. The figure shows that every time a SGD is used CBF significantly decreases without any differences in AO pressure.
Abstract 198: Dexmedetomidine During CPR Blunts the Increase in Oxygen Consumption in Early ROSC
Authors: Badugu Srinivasarao , Shih Andre , Kaliki Venkata Giridhar , Haque Ikram , Zaritsky Arno , Udassi Jai P
Published: April 2024

Introduction:
Cardiac arrest significantly increases endogenous catecholamines, which stimulates increased oxygen consumption after ROSC. In animals, adrenergic blockade during and immediately after CPR improves post arrest cardiac function. Dexmedetomodine has sympatholytic effects both in animal and human studies.

Hypothesis:
Dexmedetomidine given during CPR reduces oxygen consumption after ROSC as compared with standard CPR.

Methods
Sixteen anesthetized & ventilated (2 months old) farm pigs (UF Research Swine) of either sex were blindly randomized (8/group) after induction of ventricular fibrillation (via direct right ventricular current) to receive either dexmedetomidine (2 mcg/kg) or saline placebo after the first minute of chest compressions during CPR per AHA guidelines. Chest compressions were delivered at 100/min by a pneumatic compressor device (Thumper, Michigan instruments, USA) and 21% FiO
2
was used for ventilation. Oxygen consumption was measured from exhaled gas analysis at 15, 30, 60, 90 and 120 minutes after ROSC using a metabolic measurement system (TrueOne® 2400, Parvomedics, USA). Data (mean±SD) was analyzed using a mixed linear model (SAS Proc MIXED). We used an unpaired t-test for the differences between groups at each time point; p-value ≤0.05 was considered significant.

Results
Oxygen consumption (% change from baseline) was significantly lower in the dexmedetomidine group, 121%±4.16, vs. Saline, 143%±5.32, p=0.0093. Dexmedetomidine group had significantly lower oxygen consumption at 15 minutes (111%±22 vs. 150%±29,
p
=0.0365) and at 30 minutes (114%±24 vs.151%±19,
p
=0.0122. The oxygen consumption was not significantly different at 60, 90 and 120 minutes. There was no difference between groups with reference to time to ROSC and doses of epinephrine given.

Conclusions.
Dexmedetomidine, when given during the initial cycle of chest compressions during CPR, attenuates the elevated oxygen consumption during the post ROSC period. Further studies are needed to evaluate the effects of higher doses or continuous infusion and the optimal time of administration.
Abstract 202: Predicting Successful Defibrillation with a New Algorithm Based on the Magnitude and Dominant Frequency of Ventricular Fibrillation Waveform
Authors: Wu Xiaobo , Bisera Joe , Sun Shijie , Weil Max H , Tang Wanchun
Published: April 2024

After prolonged ventricular fibrillation (VF), defibrillation after every 2 minutes of CPR, as currently recommended, not only often fails to return spontaneous circulation but also causes significant myocardial injury. This study has developed a new algorithm to predict the optimal time of defibrillation. We hypothesized that the product of the total absolute magnitudes and dominant frequency (PMD) will provide an equal or improved prediction of amplitude spectrum area (AMSA) in a pig model of CPR. Forty-eight domestic pigs weighing between 35 to 48 kg were utilized. The durations of untreated ventricular fibrillation (VF) were from 4 to 15 minutes. The electrical shock was delivered after 2 to 5 minutes of chest compression. Only the results of the first electrical shock were reported. The 5-sec strip of VF waveform prior to each electrical shock was captured to calculate PMD and AMSA. The formula calculating PMD is PMD= (|A
1
|+|A
2
|+¼+|A
i
|+¼+|A
n
|) * DF/K, where |A
i
| is the absolute amplitude of the
i
th
time-sampled data. DF is the dominant frequency.
K
is a constant factor. For PMD calculation, the frequency range from 5 Hz to 25 Hz was selected to filter the signal, for AMSA calculation, the frequently-used frequency range is from 4 Hz to 48Hz.
K
=100 was used to calculate PMD. The perfusing rhythm was restored in 20 pigs after the electrical shock, PMD was 22.95±5.01 mV·Hz in resuscitated pigs and was 10.21±3.55 mV·Hz when electrical shock failed to restore circulation (p<.001). AMSA values were 30.97±5.35 mV·Hz and 18.77±4.57 mV·Hz in resuscitated and non-resuscitated pigs, respectively (p<.001). The differences in both of PMD and AMSA between resuscitated and non-resuscitated pigs were highly significant (p<.001). For PMD, the calculated threshold was 16 mV·Hz when the sensitivity and specificity were 100% and 89%, respectively. For AMSA, the calculated threshold was 23 mV·Hz when the sensitivity and specificity were 100% and 86%, respectively. We concluded that the product of the total absolute magnitudes and dominant frequency (PMD) predicts the successful defibrillation during CPR as effectively as amplitude spectrum area (AMSA).
Abstract 204: Extracorporeal Membrane Oxygenation Supported Cardiopulmonary Resuscitation Is Not Associated with Increased Survival Compared to Conventional Cardiopulmonary Resuscitation for Pediatric In-Hospital Cardiac Arrest in the United States
Authors: Lowry Adam , Graves Daniel E , Shamszad Pirouz , Cabrera Antonio G , Morales David L S , Mott Antonio , Joseph Rossano W
Published: April 2024

INTRODUCTION:
Survival after cardiopulmonary resuscitation (CPR) in children remains poor. The use of extracorporeal membrane oxygenation (ECMO) during or shortly after CPR (E-CPR) has been advocated as a strategy to improve outcomes. However, previous studies have been limited by lack of a conventional CPR (C-CPR) control group.

HYPOTHESIS:
E-CPR is associated with improved survival to hospital discharge compared with C-CPR.

METHODS:
Retrospective review of the 2000, 2003, and 2006 Kids' Inpatient Database, a large nationally representative database of pediatric hospital admissions, was performed. All episodes of CPR were identified; E-CPR was defined as the use of ECMO on the same day as CPR. Propensity scores were constructed reflecting the likelihood of E-CPR with arrest. Univariate, multivariable, and propensity matched analyses were performed to assess the influence of E-CPR on survival.

RESULTS:
Out of 8.6 million pediatric hospitalizations, 9,000 CPR events were identified, of which 82 were E-CPR (0.9%). Factors associated with E-CPR use included age > 1 year, congenital heart disease, myocarditis, and hospitalization in a children's hospital (p<0.001 for all). E-CPR was associated with higher hospital charges (median $187,661, interquartile range (IQR) $107,865 - $311,196) compared to C-CPR (median $23,157, IQR $5,875 - $92,004) (p<0.001). Overall, hospital mortality was significantly higher with E-CPR (65.9%) compared to C-CPR (50.9%) (OR 1.9, 95% CI 1.2 - 2.9). Other factors associated with increased mortality after CPR included age > 1 year, sepsis, congenital heart disease, and acute renal failure (p<0.001 for all). Multivariable analysis controlling for age, hospital type, and comorbid conditions revealed no survival difference between E-CPR and C-CPR (OR 0.94, 95% CI 0.6-1.5). Propensity matched analysis also demonstrated similar survival between E-CPR and C-CPR (OR 0.68, 95% CI 0.4-1.2).

CONCLUSIONS:
E-CPR is rarely utilized for pediatric in-hospital cardiac arrest in the US. E-CPR was not associated with improved survival compared to C-CPR. However, E-CPR was associated with an 8 fold increase in hospital charges. Further study is needed to identify patients most likely to benefit from this resource-intensive therapy.
Abstract 205: The Effect of Chest Compressions on ETCO
2
Levels During Out-of-Hospital Cardiac Arrest
Authors: Idris Ahamed H , Babaeizadeh Saeed , Daya Mohamud , Edelson Dana , Firoozabadi Reza , Helfenbein Eric , Zhou Sophia
Published: April 2024

Background
Previous investigations have suggested that end-tidal CO2 (EtCO2) values are proportional to cardiac output over a wide range of flow rates, including very low flow rates. Cardiopulmonary resuscitation (CPR) is an integral part of therapy that provides circulatory support for cardiac arrest patients. Therefore, we hypothesize that during cardiac arrest, EtCO2 levels are higher during periods when chest compressions are being performed compared to periods without chest compressions.

Objective
Compare EtCO2 values during periods of CPR with and without chest compressions in out-of-hospital cardiac arrest (OHCA) patients.

Methods
Recordings from 128 OHCA patients with both capnogram and chest compression waveforms were collected from 2008 to 2010 in two EMS agencies in Oregon and Texas. Recordings were manually reviewed to select segments recorded during cardiac arrest. An automated technique separated the intervals with chest compressions (27 hours) and intervals without chest compressions (15 hours). For each patient, the average EtCO2 values in the intervals with and without chest compressions were calculated and compared to determine the impact of chest compressions on the EtCO2 levels.

Results
The table below summarizes the results. For 112 patients the mean EtCO2 value was higher in intervals with chest compressions compared to those without chest compressions. For the other 16 patients, there was a small decrease in EtCO2 values during chest compressions. A paired t-test shows that the mean EtCO2 values with chest compressions (27.1 ± 13.1 mmHg) and without chest compressions (22.2 ± 12.1 mmHg) are significantly different (p < 0.0001).

Conclusion
For most OHCA patients, chest compressions increased the EtCO2 level, which may reflect an improvement in cardiac output. Monitoring EtCO2 during CPR could provide valuable feedback on the quality of CPR. Further study is required to determine factors that increase the EtCO2 during chest compression.
Abstract 219: Combination of Algorithms to Decrease Preshock Pause for Automated External Defibrillators
Authors: Didon Jean-philippe , Jekova Irena , Ménétré Sarah , Stoyanov Todor , Krasteva Vessela
Published: April 2024

BACKGROUND
Long pre-shock ‘hands-off’ intervals without chest compressions (CC) are associated with defibrillation failure. Current guidelines recommend shortening the ‘hands-off’ intervals. The aim of this study is to present the performance of a Shock advisory System (SAS) which is designed for triggering a fast ECG analysis at minimal delay after the end of chest compression (EoCC).

METHOD
A subset of 1263 strips is identified from 311 Out-of-hospital cardiac arrest (OHCA) interventions. AED rhythms include 1182 Non-Shockable strips (788 asystoles (ASYS), 394 other non-shockable rhythms (ONS)), and 81 ventricular fibrillations (VF). The SAS with minimum ‘hands-off’ intervals first detect the real end of CC (ReEoCC) offset considered as the earliest triggering point for a reliable ECG analysis without CC artifacts. Then, it performs a fast ECG analysis to lead to “Shock/No shock” decision. Specificity (Sp) for ASYS and ONS and sensitivity (Se) for VF are computed

RESULTS
The ECG analysis is triggered immediately at ReEoCC. The gain in time for earlier starting of the ECG analysis is found to be 5.6±3.6 seconds. The accuracy of the SAS is tested for 6 seconds analysis duration. The SAS “Shock/No shock” decision is provided 10.6±3.9 seconds earlier than the current AED decision. The SAS performance is compared to the AHA recommendations for Sp, Se and 90% one-sided lower confidence limit (LCL90) for noise-free signals (Table 1).

CONCLUSION
The accuracy of SAS for fast ECG analysis at minimal delay after the end of CC fulfills the AHA goals (Sp/Se and LCL90) for ASYS, ONS and VF rhythms. A reduction of ‘hands-off’ time of 10.6 seconds (between end of CC and end of analysis) in average can be expected, when compared to current AED decision delay. Table 1: Accuracy of SAS with minimum ‘hands-off’ intervals
Abstract 235: Old Age Is Independently Associated with Short Duration of Cardiopulmonary Resuscitation
Authors: Song Tae Ho , Kim Kyuseok , Kang Kyeong Won , Cha Won Chul , Lee Jae Hyuk , Jo You Hwan , Kim Tae Yun , Kim Yu Jin , Lee Jin Hee , Rhee Joong Eui
Published: April 2024

Introduction
The optimal duration of cardiopulmonary resuscitation (CPR) is unknown. Also the factors associated with the duration of CPR are not well known. We investigated that the old age might be the independent factor for short duration of CPR.

Methods
A prospective database including out-of-hospital arrest patients who underwent CPR at one academic emergency department from 2008 through 2010 was analyzed retrospectively. Exclusion criteria were as follows: age under 18 years, traumatic causes of arrest, who gained ROSC. Patients were divided into two groups by the duration of CPR; the shorter group (CPR duration < 30 minutes) and the prolonged group (CPR duration > 30 minutes). Univariate and multivariate analyses were used to identify the factors associated with the short duration of CPR.

Results
A total of 168 patients were enrolled. The shorter group (106 patients) showed 63% of total patients whereas prolonged group (62 patients) showed 37%. Among the factors examined, old age (>65years, adjusted odds ratio 2.072, 95% CI 1.044-4.111) and place where arrest took place were found to be independently associated with the short duration of CPR.

Conclusion
Old age might be one of the factors that is independently associated with the short duration of CPR.
Abstract 28: A Paradoxical Increase in VF Prevalence Over the Period Immediately After Sudden Cardiac Arrest
Authors: Kaneko Hiroshi , Hatanaka Tetsuo , Nagase Aki , Noguchi Hiroko , Marukawa Seishiro
Published: April 2024

Introduction:
Ventricular fibrillation and/or tachycardia (VF/VT) is an important cause of sudden cardiac arrest. When left untreated, as the period with no myocardial blood flow progresses, the initial VF/VTs degrade into asystole with the VF/VT prevalence decreasing over the period from collapse to initial ECG documentation (down time). Using the national registry of out-of-hospital cardiac arrest, we have examined how the VF/VT prevalence changed with the down time.

Methods and Results:
Initial ECG rhythms of 173,767 out-of-hospital witnessed cardiac arrest patients were obtained. Bystander CPR was provided in 60,280 patients and those patients were excluded from the analysis. The down time was defined as the time from witnessed collapse to the time of initial ECG documentation by the EMT. Down time was 0 (zero) when cardiac arrest was witnessed by the attending EMTs in patients under ECG monitoring. At time zero, the prevalence of VF/VT, PEA and asystole were 12.2% (311/ 2,511), 43.0% (1,097/ 2,551) and 44.8% (1,143/ 2,551), respectively (Fig). The VF/VT prevalence gradually increased with the down time to reach a maximal value of 23.2% at 7 minutes and almost exponentially decreased thereafter. The prevalence of asystole decreased initially and then increased. The prevalence of PEA decreased almost linearly.

Conclusions:
The reasons for the initial and unexpected increase in the VF/VT prevalence remain only to be speculated. Documentation of time of collapse relied mostly on the bystander interview. Although thus contaminated time data may have created a deceptive initial increase of the VF/VT prevalence, it does not completely explain the initial increase in the VF/VT prevalence. The initial decrease of the prevalence of asystole suggests that asystole may converts spontaneously into VF/VT. Initially documented VF/VTs appear to consist of “true” VF/VTs that start as VF/VT as well as those VF/VTs that originate from PEA and/or asystole.
Abstract 5: Indirect Brain Injury Resulting from Severe Burns Results in Estrogen-Reversible Elevations of Markers of Alzheimer's Disease
Authors: Wigginton Jane G , Pepe Paul E , AbdelFattah Kareem R , Maass David L , Idris Ahamed H , Minei Joseph P , Gatson Joshua W , Simpkins James W
Published: April 2024

Background:
Prior studies have found that patients with severe burns may suffer neurocognitive changes. While frequently attributed to psycho-social issues, recent data from our lab revealed a substantial, rapid and sustained (30 min - 7 day) increase in rat brain inflammation following burns that is blunted by a single post-burn dose of estrogen. Other brain injury processes, such as TBI and stroke have shown an accelerated accumulation of Aβ40, Aβ42, and pTau, leading to a clinical picture of early Alzheimer's disease (AD). We hypothesized that similar AD processes may be triggered in severe burn injury, and altered by post-burn estrogen.

Methods:
149 male rats were given a 3° 40% TBSA scald burn. Rats were randomized into 3 groups: Group 1 (0.5mg/kg of 17β estradiol (E2) 15 min after injury); Group 2 (placebo); and Group 3 (sham-burn control). These rats were sequentially sacrificed at 0.5, 1, 2, 4, 6, 8, 12, 18, 24 hours post-burn. An additional 24 rats were sacrificed 7 days post-burn. Brain tissue IL-6, Aβ40, Aβ42, and pTau were measured using ELISA.

Results:
Compared to placebo, early estrogen treatment significantly decreases (~90%) brain levels of IL-6 at all measured time points. At 7 days post-burn, rats receiving E2 exhibited similar Aβ40, Aβ42, and pTau to the unburned group, while those receiving placebo were significantly elevated.

Conclusions:
17β estradiol not only mitigates the early-onset, sustained brain inflammation following burn injury in a rat model, but also significantly decreases brain levels of Aβ40, Aβ42, and pTau. We hypothesize that other injuries causing acute, remote brain inflammation (such as cardiac arrest) may trigger similar AD-like brain changes.
Abstract 15251: Systemic Maternal Inflammation and Neonatal Hyperoxia Induce Remodeling and Left Ventricular Dysfunction in Mice
Authors: Velten Markus , Hutchinson Kirk R , Gorr Matthew W , Wold Loren E , Lucchesi Pamela A , Rogers Lynette K
Published: April 2024

Markus Velten, 2011 Finalist and Presenting Author
Abstract 12935: Hypocaloric Diet and Exercise Training Improves the Chemoreflex Sensitivity in Patients with Metabolic Syndrome and Obstructive Sleep Apnea
Authors: Maki-Nunes Cristiane , Toschi-Dias Edgar , Cepêda-Fonseca Felipe X , Rondon Maria U , Alves Maria J , Drager Luciano F , Aguilar Adriana M , Sommers Virend K , Lorenzi-Filho Geraldo , Negrão Carlos E , Trombetta Ivani C
Published: April 2024

Cristiane Maki-Nunes, 2011 Finalist and Presenting Author
Valvular Heart Disease: From Bedside to Bench and Back Again
Authors: Gillam Linda
Published: April 2024

The discipline of valvular heart disease owes much to Rene Laennec since the stethoscope he invented remains the primary tool with which valve disease is clinically recognized. The ability to diagnose stenotic and regurgitant lesions on the basis of their characteristic murmurs is a core element of the bedside examination. For many years, valvular heart disease remained an understudied family of conditions. However, in recent years we have gained a better understanding of the pathophysiology of valve disease through research that has included sophisticated analyses of the beating human heart, studies of animal and in vitro models of valve dysfunction as well as biochemical and microscopic examination of diseased valves. There has also been preliminary study of the feasibility of growing valves in vitro. Indeed, the study of valve disease has transitioned from the bedside to the bench. Investigation of two of the most common and clinically important conditions, aortic stenosis and functional mitral regurgitation, has led the way aided by advances in imaging methods for quantitating the progression of disease. For example we now appreciate the similarities and differences between calcific aortic valvular disease and atherosclerosis and know that functional mitral regurgitation, long defined by the absence of structural leaflet changes is, in fact associated with leaflet enlargement. With this new understanding that these studies have provided, has come the potential for new forms of treatment such as pharmacologic and non-surgical mechanical intervention for valve disorders, the treatment of which has heretofore been limited to surgical intervention for end-stage disease. Using the information we have gained at the bench to inform new bedside treatments will define future management of valve disease.
Abstract 67: Direct Mail Improves Knowledge of CPR Guidelines 2010 in Primary Care: A Randomized Study
Authors: Løfgren Bo , Secher Niels , Mikkelsen Mette Marie , Adelborg Kasper , Rubak Jens Mørch , Vedsted Peter
Published: April 2024

Background:
Resuscitation councils publish new guidelines on resuscitation every 5 years. Often there is a significant delay on implementing new guidelines into clinical practice. Direct-mail is an inexpensive way of disseminating information to primary care physicians (PCP) and may improve implementation of new CPR guidelines 2010. Accordingly, the aim of this study was to investigate whether direct-mail improved knowledge on new CPR guidelines among PCPs.

Methods:
All primary care clinics in Central Region Denmark were randomized to receive either direct-mail (intervention) or no direct-mail (control). The direct-mail consisted of a cover letter outlining changes in CPR guidelines and a poster on CPR and the use of an automatic external defibrillator (AED). In clinics randomized to the intervention every single PCP received a personal direct-mail. Two weeks later a multiple-choice questionnaire on CPR guidelines together with items on characteristics of the PCP were mailed to PCPs in all clinics. Non-responders received a reminder with an additional questionnaire after 20 days.

Results:
A total of 830 (direct-mail, n=408; control, n=422) PCPs from 351 primary care clinics were included in the study. Overall response rate was 58%. Demographic characteristics were comparable in the two groups. The majority (91%) of PCPs receiving direct-mail stated they were familiar with the new CPR Guidelines 2010 compared to 72% in the control group (P<0.0001). Direct-mail improved the knowledge of the new recommended chest compression depth (67% vs. 40%, P<0.0001) and the new recommended chest compressions frequency (62% vs. 40%, P<0.0001).

Conclusion:
Direct-mail improves disseminating knowledge on changes in CPR guidelines and thus helps implement new guidelines in general practice. Organizations i.e. resuscitation councils and medical societies for primary care may consider using this inexpensive strategy for implementing changes in clinical guidelines in the future.
Abstract 8193: Echocardiographic Predictors of Progression from Paroxysmal to Persistent Atrial Fibrillation: Result from the Japanese Rhythm Management Trial II for Atrial Fibrillation (J-RHYTHM II) Study
Authors: Suzuki Takeki , Yamazaki Tsutomu , Ogawa Satoshi , Nagai Ryozo , Yamashita Takeshi ,   the J-RHYTHM II investigators
Published: April 2024

Background:
Several clinical factors such as age, hypertension, and heart failure are known to be associated with progression from paroxysmal to persistent atrial fibrillation (AF). On the other hand, which echocardiographic variables are associated with the progression remains unknown.

Method:
We used 286 patients in the J-RHYTHM II study, a randomized clinical trial examining effect of calcium channel blocker (amlodipine) and angiotensin receptor blocker (candesartan) in Japanese patients with paroxysmal AF and hypertension. Echocardiographic evaluation was performed at baseline. Left ventricular end-diastolic diameter (LVDd), left ventricular end-systolic diameter (LVDs), left ventricular ejection fraction (LVEF), interventricular septum (IVS), left ventricular posterior wall (LVPW), and left atrial dimension (LAD) were measured in a standard manner. The end point was development of persistent AF, defined as incidence of AF lasting for longer than 7 days and/or need of electrical cardioveresion. Cox proportional hazards models were used to examine the associations between echocardiographic variables and development of persistent AF.

Results:
Among echocardiographic variables, LVDd, LVDs, and LAD were associated with development of persistent AF (Table). Only LAD was significantly associated with progression from paroxysmal into persistent AF after adjustment by after adjustment by age, sex, and other potential confounding factors. One
millimeter
increase in LAD was associated with 7% increased risk of developing persistent AF (HR 1.07, 95% CI 1.01-1.14). This means that a 10 mm increase in LAD was associated with twice the risk of developing persistent AF (HR 1.97, 95% CI 1.09-3.58).

Conclusion:
LAD is associated with progression from paroxysmal to persistent AF in patients with paroxysmal AF and hypertension. LAD may be a good echocardiographic predictor of AF progression.
Abstract 8232: Obesity-Related Arterial-Ventricular Stiffening in Children
Authors: Harada Kenji , Harada Yukiko , Toyono Manatomo
Published: April 2024

Background:
Obesity is associated with structural and functional changes in the heart. Increases in arterial, ventricular systolic, and ventricular diastolic elastance (stiffness) may contribute to the pathogenesis of cardiac dysfunction. However, there is little information on arterial-ventricular stiffness and coupling in obese children. The purpose of the study is to assess the relationship between body mass index (BMI) and arterial-ventricular stiffening and coupling in children.

Methods:
Echocardiography with tissue Doppler imaging was performed in 303 children aged 6 to 15 years (BMI 12 to 34kg/m2). Left ventricular (LV) end-diastolic volume, LV mass, transmitral peak flow velocity (E), and mitral annular myocardial velocity (Em) were measured. LV mass/volume ratio was calculated. Stroke volume (SV) was measured using aortic diameter and pulsed Doppler velocity profile. SV was indexed for body surface area (SVI). Effective arterial elastance (Ea) was estimated by end-systolic pressure/SVI. End-systolic elastance (Ees) was calculated by a modified single-beat method using systolic and diastolic blood pressure, stroke volume, ejection fraction, timing intervals, and an estimated normalized ventricular elastance at arterial end diastole. Operant Ed was calculated from Doppler indices reflective of atrial pressures (E/Em) and the diastolic filling volume (SV).

Results:
Ea, Ees, and Ed all increased significantly with BMI(r = 0.35, p < 0.01, 0.26, p < 0.01, and 0.15, p < 0.05, respectively). Arterial-ventricular coupling (Ea/Ees ratio) did not change with BMI. LV mass/volume ratio was positively associated with increased BMI (r = 0.48, p < 0.01). The increased LV mass/volume ratio was due to a greater increase in LV mass to LV end-diastolic volume. There were weak but significant relationships between LV mass/volume ratio and Ees (r = 0.14, p < 0.05), Ea (r = 0.18, p < 0.01), and Ed (r = 0.15, p < 0.05).

Conclusions:
The present study suggests that higher BMI is associated with increases in arterial, ventricular systolic, and ventricular diastolic stiffness in children. This combined arterial-ventricular stiffening in obese children may contribute to the increased prevalence of later cardiovascular diseases.
Abstract 8293: Atrial Fibrillation and Stroke in the General Medicare Population: a Fifteen Year Perspective (1992-2007)
Authors: Herzog Charles A , Solid Craig A
Published: April 2024

Introduction:
Non-valvular atrial fibrillation (AF) is a major cause of stroke in the elderly, and anticoagulation is indicated in these pts. Due to changing demography of the US population (“graying of America”), AF prevalence and characteristics of AF pts may have changed over time. Temporal trends in warfarin therapy potentially reflect evolving evidence-based practice patterns and pt characteristics.

Methods:
We searched the 5% Medicare database (n ∼ 1.8 million pts/cohort yr) to identify AF pts (no ESRD, age 65+) in 1992-2007. We used Medicare claims to count ischemic and hemorrhagic strokes after the AF diagnosis. We used 3+ prothrombin time (PT/ INR) claims as a surrogate for warfarin use (a previously validated method). For each year's cohort, we calculated the rate of stroke events (per time at risk) and warfarin use within the cohort. CHADS2 risk scores and contra-indications to warfarin use were derived from diagnosis codes.

Results:
The prevalence of AF within the elderly Medicare population grew from 3% in 1992 (n= 40,094; 37% age 65-74, 44% 75-84, 20% 85+; 44.7% male, 94.1% white, 4.1% black) to 7% in 2007 (n= 72,615; 31% age 65-74, 45% 75-84, 24% 85+; 47.7% male, 93.7% white, 3.7% black). The percent of pts at “high” risk for stroke (CHADS2 score >2) rose from 20% to 28%. Warfarin use progressively increased from 27% in 1992 to 63% in 2007, despite increase in warfarin contra-indications from 32 to 42%. The Figure details stroke rates and warfarin use over time.

Conclusion:
Progressively more elderly AF pts have received warfarin therapy from 1992 to 2007. The characteristics of AF pts receiving warfarin have changed over time, reflecting temporal changes in practice patterns. The 15 yr decline in ischemic strokes (with no change in hemorrhagic stroke) is temporally co-incident with increasing warfarin use. Newer oral anti-coagulants without PT/INR monitoring requirements may further increase the number of elderly AF pts receiving therapeutic anti-coagulation.