bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3057: Tissue Engineered Three-layered Artery Using Hemodynamically-equivalent Pulsatile Bioreactor
Authors: Iwasaki Kiyotaka , Kojima Koji , Kodama Shota , Paz Cristina , Umezu Mitsuo , Vacanti Charles A 
Published: July 2021

Introduction: Due to lack of anti-thrombogenicity in small diameter vascular prostheses, there is a strong demand for tissue-engineering autologous small-diameter graft, which can function in arterial high pressure and flow environments. Here, we investigated a potential to engineer a robust and three-layered artery.
Methods: Endothelial cells (ECs), smooth muscle cells (SMCs) and fibroblasts were isolated with collagenase from bovine artery, then each cell were primary cultured. A polyglycolic acid (PGA) sheet seeded with SMCs was wrapped on silicon tube with a diameter of 6 mm. After 4 days of incubation, a polycaprolactone sheet seeded with SMCs was over-wrapped. Then, after incubation for another 3 weeks, a PGA sheet seeded with fibroblasts was over-wrapped and incubated for another 2 days. The luminal tube was then removed out, and the tubular tissue was mounted on a specially designed chamber. The luminal areas of engineered tubular structure were seeded with half a million of ECs and incubated for another 2days. Finally, bioreactor culture was performed for more 2weeks (n=10). Pulsatile flow and pressure were gradually increased from mean flow rate of 0.2(0.5/0) L/min and mean pressure of 20(40/15) mmHg to 0.6(1.4/0.2) L/min and 100(120/80) mmHg.
Results: Scanning electron microscopic examination and von Willebrand factor stain revealed that ECs lined over the lumen and oriented by flow stimulation. Stain of Elastica Van Gieson and Masson Tricrome showed that a lot of elastin components and collagen were produced in the tissue engineered grafts. Stain for α-SMA, calponin, and vimentin showed that engineered arteries were constructed from SMC and fibroblasts regions and morphologically organized as three layered. Tensile tests demonstrated that ultimate strength of engineered arteries were increased by 6.7 times as compared with that of biodegradable polymers (n=8) and become equivalent to that of the native arteries (Native: 882±133kPa, Engineered: 827±155kPa) (each n=8).
Conclusion: A robust and three-layered small-diameter elastic artery was engineered from vascular cells and biodegradable polymers using the hemodynamically-equivalent pulsatile bioreactor.
Abstract 3711: School-based Early Prevention Interventions Decrease Body Mass Index Percentiles During School Year, but Children Experience Increase in Percentiles During Summer
Authors: Hollar Danielle , Hollar Theodore L , Agatston Arthur S 
Published: July 2021

Introduction: The Healthier Options for Public Schoolchildren (HOPS) Study aims to understand the efficacy of early prevention efforts addressing nutrition and physical activity in elementary school setting during the school year.
Hypothesis: We assessed the hypotheses:

HOPS interventions improve age and gender-specific body mass index (BMI) percentiles more so than traditional dietary and physical activities;

intervention children maintain healthier BMI percentiles during summer vacation compared to controls.

Methods: HOPS, in its 3
rd
year, includes approximately 3,200 children (48% Hispanic) in six elementary schools (4 intervention; 2 control). Data are collected in fall and spring. Interventions include modified dietary offerings, nutrition and lifestyle curricula, school gardens, and other wellness projects, with the goal of reducing childhood obesity rates in a manner that is replicable in other public school settings.

Results: Overall, data for the academic year 2 show statistically significant differences between treatment groups with respect to changes in BMI percentiles. Analyses of subgroups show trends towards greater improvements for intervention children, but only those classified as normal and in the 3
rd
quintile at study baseline experienced statistically significantly improvement. Data analyzed for summer vacation time show increases in BMI percentiles for both intervention and control children with the exception of intervention children classified as overweight or in the 5
th
quintile at study baseline. Control children classified as at risk or overweight as well as those in the 3
rd
, 4
th
, and 5
th
quintiles experienced greater increases in their BMI percentiles during summer.

Conclusions: Early results show HOPS interventions improve BMI percentiles of elementary-aged children during the school year. However, all children appear to be losing ground during summer vacation as their BMI percentiles increase during this time.

Changes in BMI Percentiles during School Year
Abstract P167: Pentax-AWS is More Useful Than Macintosh Laryngoscope and Airtraq to Establish Tracheal Intubation while Uninterrupted Chest Compression: a Comparative Study with Manikin
Authors: Koyama Jun-ichi 
Published: July 2021

Purpose. In resuscitation, chest compression is essential, and it should be performed appropriately and uninterruptedly to obtain the return of spontaneous circulation and breathing. However, attempt of tracheal intubation with the Macintosh laryngoscope (Mac) occasionally needs a temporary pause of chest compression and delays its resuming. Consequently, we studied the efficacy of the new video-laryngoscopes, PENTAX-AWS (AWS) and Airtraq (ATQ) as device used for tracheal intubation while nonstop chest compression.
Materials and Methods. Twenty seven participants including 11 non-anesthetic doctors, 1 paramedic, 11 nurses and 4 medical students enrolled in this study. At first, Participants and supplementary assistant who concentrated on chest compression simulated CPR with the use of Resusci Anne Simulator manikin (Laerdal) placed on medical emergency bed as 30:2 protocol proposed in 2005 AHA Guidelines. Strength and rhythm of the compression were monitored in real-time by PC skill-reporting system. After the chest compressions became constant, participants were requested to intubate with using Mac, AWS and ATQ in both situations without chest compression and while the compression.
Results. Tracheal intubation was successfully achieved within 3 attempts by 92.6% participants in Mac and 100% in AWS and ATQ without chest compression, and 66.7% in Mac, 100% in AWS and 81.5% in ATQ while chest compression. Rate of success in the 1st attempt was 55.6% in Mac, 96.3% in AWS and 51.9% in ATQ while compression. Time to intubate while compression with AWS was 14.6s, which was significantly shorter than 26.1s with ATQ in the successful attempts.
Conclusions. With using AWS, high success rate of tracheal intubation was achieved even in chest compression situation in comparison with the other two devices. Macintosh laryngoscope is the most inconvenient among these devices when tracheal intubation is attempted while chest compression. ATQ showed significant decrease of success rate in compression situation despite it achieved 100% success without compression. PENTAX-AWS is expected to be more useful than Macintosh laryngoscope and Airtraq to establish tracheal intubation while uninterrupted chest compression in clinical use.
Abstract 3490: Mechanistic Involvement of Myeloperoxidase in the Pathogenesis of Atrial Fibrillation
Authors: Rudolph Volker , Andrie Rene , Friedrichs Kai , Rudolph Tanja K , Klinke Anna , Lau Denise , Scoecs Katalin , Schrickel Jan , Lewalter Thorsten , Nickenig Georg , Meinertz Thomas , Willems Stephan , Baldus Stephan 
Published: July 2021

Background: Observational clinical and ex-vivo studies have established a strong association between atrial fibrillation (AF) and inflammation. However, whether inflammation is cause or consequence of AF and which specific inflammatory mediators increase atrial susceptibility to fibrillate remain elusive. Herein, we provide evidence for mechanistic involvement of myeloperoxidase (MPO), a heme enzyme abundantly expressed by neutrophils, in the pathophysiology of AF.
Methods and Results: Patients with AF assessed by pacemaker interrogation not only exhibited higher circulating plasma levels of MPO (503.1 [IR:404.6 –880.7] vs. 437.8 [IR:348.9 – 488.0 pmol/l; p=0.03; n=42), they also revealed an increased MPO burden in explanted left atrial tissue as compared to patients devoid of AF. In AF-patients MPO co-localized with markedly increased formation of 3-nitro and 3-chlorotyrosin, protein oxidations known to be catalyzed by MPO. Myeloperoxidase knock-out mice, pretreated with angiotensin II infusion for 2 weeks yielding increased neutrophil activation, revealed strikingly attenuated vulnerability for AF during right atrial electrophysiological stimulation as compared to wild type mice (probability of AF-induction: 3.0 vs. 12.7%; p<0.01). Whereas the electrical homogeneity of the atrial myocytes was not altered between the groups, atria of MPO knock out mice were indicative of significantly reduced atrial fibrosis and markedly reduced formation of 3-chloro- and 3-nitrotyrosine.
Conclusion: In conclusion, the current findings not only underscore the significance of neutrophil activation as a critical pathophysiological prerequisite of AF, but reveal that MPO - by oxidatively modifying protein residues and increasing fibrosis of atrial myocytes - is causally linked to the initiation and perpetuation of AF.
Abstract 3684: Short-term Caloric Restriction Reverses Age-associated Vascular Endothelial Dysfunction in Older Mice
Authors: Rippe Catarina , Connell Melanie L , Lesniewski Lisa A , Donato Anthony J , Seals Douglas R 
Published: July 2021

Backgound: Oxidative stress-mediated, nitric oxide (NO)-dependent vascular endothelial dysfunction develops with aging, increasing the risk of cardiovascular diseases. As such, it is important to identify interventions that can prevent/restore the loss of endothelial function with aging. Caloric restriction (CR) is associated with several physiological benefits and increased longevity in rodents. Some of these benefits are linked to increases in SIRT-1, an enzyme activating endothelial NO synthase (eNOS), and reductions in oxidative stress. We tested the hypothesis that short-term CR would restore vascular endothelial function by improving NO bioavailability and reducing oxidative stress in old B6D2F1-mice, and that this would be associated with increased expression of SIRT-1 and eNOS.
Methods: Old (30 months) male B6D2F1-mice were either fed ad libitum (AL, n=6) or were restricted to 70% (3.2g) of their normal food intake for 6 weeks after 2 weeks of progressive restriction (n=6). Carotid artery dilation was assessed ex vivo in response to the endothelium-dependent dilator acetylcholine (ACh) [before and after incubation with the eNOS inhibitor, NG-nitro-L-arginine methyl ester (L-NAME) or the superoxide dismutase mimetic, TEMPOL] and the endothelium-independent dilator sodium nitroprusside (SNP).
Results: ACh-induced dilation was markedly impaired in the AL mice, but was completely restored in the CR mice (63±10% vs. 98±1%, P<0.01). L-NAME decreased ACh dilation by 97% in CR, but only 56% in AL mice, indicating increased NO bioavailability in the CR mice. TEMPOL restored ACh-mediated dilation in AL mice (to 97±1%), but had no effect in CR mice. Aortic protein expression of SIRT-1 and eNOS (western blotting) were 80 –90% higher in CR vs. AL mice (eNOS: 1.9±0.1 vs. 1.0±0.4 P<0.05; SIRT-1: 1.8±0.2 vs. 1.0±0.2, P=0.05). Dilation to SNP was similar in the CR and AL mice (97±1% vs. 96±2%, P=0.63).
Conclusion: Short-term CR selectively restores endothelium-dependent dilation in older B6D2F1-mice by increasing NO bioavailability and reducing oxidative stress. These effects are associated with increased vascular expression of SIRT-1 and eNOS. CR may be an effective intervention for reversing age-associated vascular endothelial dysfunction.
Abstract 2751: Correlation of Left Atrial Voltage Maps with Cardiovascular MR Provides Evidence of Pre-existent Scar in Atrial Fibrillation Patients
Authors: Woo Jeongjoo , Peters Dana C , Wylie John V , Nezafat Reza , Hauser Thomas H , Josephson Mark E , Manning Warren J 
Published: July 2021

Introduction: There is increasing evidence for and interest in detecting electrically silent left atrial (LA) myocardium which may be the substrate of atrial fibrillation (AF). Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) might detect these areas of pre-existent scar as high signal in the LA wall. We sought to correlate the extent low-voltage areas in AF patients with clinical parameters of LA volume and type of AF, and to correlate areas of low voltage with areas of high signal on LGE CMR, indicating areas of scarred tissue.
Methods: Twenty-two patients with AF underwent high resolution atrial LGE CMR on a 1.5 T CMR scanner and bipolar voltage electroanatomic mapping (Carto, Biosense Webster). The number of the LA mapping points with low (< 0.1mV) voltage was calculated for each patient. LA systolic volume was measured, indexed to BSA. Using the voltage maps, blood-LA contrast to noise ratio (CNR) was measured on the LGE CMR images in two areas, low and high voltage areas (N=10). Hypothesis testing used t-tests and p<0.05.
Results: The average extent of LA low voltage was 8 % of the LA. Four (18%) patients had no low voltage regions. The extent of low voltage for patients with non-paroxysmal vs. paroxysmal AF was 11 ± 13% vs. 4 % ± 5 % (p=0.08). The extent of low voltage for patients with larger than median LA volumes vs. smaller LA volumes was 12 ± 13% vs. 1 ± 1 % (p=0.027). In 10 patients in which LGE was measured in low and high voltage regions, the CNR was 10 vs. 6 (p=0.016).
Conclusions: Patients with extensive low voltage regions in the LA have larger LA volumes. The CNR is higher in low-voltage regions, suggesting that such regions of possible scar can be identified by LGE CMR.
This research has received full or partial funding support from the American Heart Association, AHA National Center.
Abstract 2890: Nesiritide Enhances Myocardial Protection during the Revascularization of Acutely Ischemic Myocardium
Authors: Lazar Harold L , Bao Yusheng , Siwik Deborah , Frame Jeffrey , Mateo Carlos San , Colucci Wilson 
Published: July 2021

Nesiritide, a recombinant human B-type natriuretic peptide, has been used in conjunction with inotropic agents in the postoperative management of low cardiac output and pulmonary hypertension. However, its effects on intraoperative myocardial protection are unknown. This study was therefore undertaken to determine whether Nesiritide could enhance myocardial protection when given intraoperatively in a porcine model simulating urgent CABG surgery. Twenty pigs underwent occlusion of the second and third diagonal coronary arteries using snares for 90 minutes followed by 45 minutes of antegrade, cold blood cardioplegic arrest and 180 minutes of reperfusion on cardiopulmonary bypass(CPB) during which time the snares were released. Ten animals received an IV bolus of Nesiritide(2ug/kg) at the initiation of coronary occlusion followed by a 0.01ug/kg/min IV infusion during coronary occlusion, cardioplegic arrest, and reperfusion on CPB. Ten other animals underwent the same protocal without Nesiritide(placebo). Infarct size was assessed by the area of necrosis/area of risk(AN/AR) using histochemical staining, endothelial function by the % change in coronary vasodilation using ring chamber methodology, and lung edema using % change in wet/dry weights. The data is expressed as the mean+/− standard deviation. Nesiritide treated hearts had significantly decreased infarct size, better preservation of endothelial function, and less lung edema. In a porcine model of acute coronary occlusion simulating urgent CABG surgery, the intraoperative infusion of Nesiritide limited myocardial damage. These data suggest that IV Nesiritide infusions may afford increased myocardial protection when administered intraoperatively during the revascularization of acutely ischemic myocardium.
RESULTS
Abstract 4104: Organization of Atrial Signals is Critical Prior to Cardioversion of Atrial Fibrillation with Intravenous Flecainide: Insight from Spectral Analysis of Intracardiac Electrograms
Authors: Tuan Jiun , Kundu Suman , Jeilan Mohamed , Osman Faizel , Mantravadi Rajkumar , Stafford Peter , Ng G. Andre 
Published: July 2021

Introduction & Hypothesis: Studies in catheter ablation of atrial fibrillation (AF) show that an increase in cycle length (CL) and higher organization index (OI) is associated with termination of AF. We hypothesize that similar changes can be seen in chemical cardioversion with Flecainide
Methods: Patients who were still in AF at the end of catheter ablation for AF were given intravenous flecainide. OI and dominant frequency (DF) were obtained by Fast Fourier Transform of coronary sinus electrograms over 10s in AF, before and after flecainide infusion. Mean CL was also calculated.
Results: 28 patients were identified (18 paroxysmal AF and 10 persistent AF). 8 cardioverted to sinus rhythm (SR) with flecainide. In all patients, mean CL increased from 211 ± 44 ms to 321 ± 85 ms (p <0.001). Mean DF decreased from 5.2 ± 1.03 Hz to 3.6 ± 1.04 Hz (p <0.001). Mean OI was 0.33 ± 0.13 before and 0.32 ± 0.11 after flecainide (p = 0.90). Comparing patients who cardioverted to SR with those who did not, OI post-flecainide was 0.41 ± 0.12 vs 0.29 ± 0.10 (p=0.013) and relative change in OI was 29 ± 33% vs −3.9 ± 27% (p=0.016) respectively. No significant difference was noted in the change in CL and DF in the 2 groups. Logistic regression showed that a greater relative increase in OI (p=0.04), a higher OI post-flecainide (p=0.03) and SR at start of procedure (p=0.03) are independently associated with cardioversion to SR with flecainide.
Conclusion: Increase in OI, independent of changes to the CL and DF, appears critical to AF termination with flecainide. The increase in OI may reflect an increase in size and reduction in the number of re-entrant circuits, which together with slowing of atrial activation, result in return to SR.
Abstract 4191: Prognostic Significance of Normal Combined Stress, Delayed Enhancement, and Functional Cardiac Magnetic Resonance Imaging
Authors: Bingham Scott , Hachamovitch Rory 
Published: July 2021

Background: Combined adenosine stress perfusion (STRESS), myocardial delayed enhancement (MDE), and ventricular wall motion (WM) by cardiac magnetic resonance (CMR) is a promising approach to further risk stratification in patients with intermediate pre-test clinical cardiovascular risk. The prognosis conferred by normal (NL) STRESS, MDE, and WM CMR is unknown.
Methods: 1,002 consecutive patients underwent combined CMR including STRESS by gadolinium first-pass perfusion, MDE, and cine WM for suspicion of coronary artery disease (CAD) or myocardial ischemia. 577 patients had NL STRESS, 607 had NL MDE, 544 had NL WM, and 448 had NL combined CMR. 70% had no history of CAD. Follow up was performed at a mean 31 (range 12– 62) months after CMR for cardiac death (CD) all-cause death (ACD) and non-fatal myocardial infarction (MI).
Results: NL combined CMR resulted in 0.6% rate of CD per year of follow up (0.3% if no CAD history, and 1.4% with CAD history). Rates for ACD and ACD plus MI were 1.9% and 2.0%. Similar event rates were observed when each component of combined CMR was considered separately.

Conclusion: Normal STRESS, MDE, and WM CMR, both singly or in combination, confer a low risk of subsequent cardiac events.
Event Rate % per Year of Follow Up
Abstract 4652: Incidence and Mode of AF Termination During Substrate Ablation of AF Guided Solely by Complex Fractionated Atrial Electrograms Mapping
Authors: Oketani Naoya , Lockwood Evan , Nademanee Koonlawee 
Published: July 2021

One of the key end points of catheter ablation of atrial fibrillation (AF) substrate guided by complex fractionated atrial electrograms (CFAE) mapping is termination of sustained AF. But controversy exists as to how effective CAFÉ ablation is in AF termination especially in chronic AF. Thus, we carried out the following study to determine incidence and mode of AF termination including electrogram characteristics at the successful site.
Methods: Our study included 616 consecutive patients (pts); 206 (33%) were paroxysmal (PAF) and 410 (67%) chronic (CAF), who underwent CFAE ablation from Jan 2006 to Dec 2007. The recordings of electrograms at baseline, during AF termination and cycle length changes were analyzed blindly off-line; the sites of successful termination were then associated with the detailed grid of 44 regions of both atria and coronary sinus (CS).
Results: Of the 616 Pts, AF could be terminated in 203 (99 %) of PAF (64 pts [31%] with Ibutilide [Ib] ), 80% in CAF (283 pts [69%] with Ib); the remaining 20% of the chronic AF Pts required cardioversion. The termination sites were located 76% in LA, 11% in CS, and 13% in RA. The common areas of the termination are at the upper septum at the anterior aspect of the right pulmonary veins (PVs), proximal CS, posterior aspects of the left PV antrums, the ridge of LA appendage, and postero-septum of RA. AF organized and changed to atrial flutter (Afl) in 121 pts (35%), while 342 pts (65%) of the patients remained in AF with a significant increase (164 to 247 msec) in cycle length before termination. There are 3 distinct electrogram characteristics at the successful sites of tachycardia termination; 1) low voltage CFAE which the shortest cycle length in relation to the rest of the atria (42%); 2) mid-diastolic and fractionated potentials in patients whose AF converted to Afl (45%) and 3) a very low voltage fractionated potentials with the highest amplitude of the potentials was ≤ 0.06 mV (0.044 ± 0.011 mV), commonly found at the previous ablation sites (13%).
Conclusion: Substrate ablation guided by CFAE mapping successfully terminate AF in the majority of Pts. Knowledge of specific areas that have predilection to be sites of termination and electrogram characteristics may be helpful to achieve AF termination.