bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 16766: A Human Induced Pluripotent Stem Cell-Derived Engineered Cardiac Tissue Model of Pompe Disease
Authors: Raval Kunil K , De Lange Willem J , Ralphe John C , Kamp Timothy J
Published: April 2024

Background:
Infantile-onset Pompe disease is a lethal autosomal recessive lysosomal storage disorder caused by the complete loss of acid α-glucosidase activity resulting in glycogen accumulation within lysosomes. Skeletal and cardiac muscle pathology develop due to aberrant glycogen metabolism and lysosomal dysfunction. This work presents the first in vitro human cardiac tissue model of Pompe disease documenting the classic Pompe cellular phenotype within a multicellular engineered cardiac tissue preparation.

Methods:
Pompe disease-specific human induced pluripotent stem (iPS) cell derived cardiomyocyte (iPS-CMs) were seeded into a polymerizing fibrin mixture to form mechanically integrated multicellular engineered cardiac tissue (ECT) constructs that were evaluated over a one-month period in parallel with healthy human iPS cell derived ECTs. Weekly measurements of isometric force and intracellular calcium transients were recorded under varying work load imposed by electrical pacing and β1 adrenergic stimulation. Structural assessment was performed using electron microscopy and immunohistochemistry.

Results:
Healthy and Pompe iPS-CMs can form cylindrically shaped ECTs of 1-2 mm diameter and 1.5-2 cm in length composed of coupled CMs that generate force in the milli-newton range along the cylindrical axis. We report structural changes in the ECT model consistent with the hallmarks of Pompe disease including progressive intracellular glycogen accumulation, lysosomal disruption, and myofibrillar disarray. Both healthy and Pompe ECTs generate higher twitch forces in response to mechanical stretch, have a negative force-frequency relationship characteristic of immature myocardium, and have an inotropic response to dobutamine stimulation.

Conclusion:
Human iPS-CM ECTs obey the Frank-Starling law and produce calcium cycling and force kinetics that respond to β1 adrenergic stimulation. The Pompe ECT provides a novel cardiac tool in which to further study the pathophysiology of this disease and test novel therapeutic approaches.
Abstract 16786: Er71 Transcriptionally Activates Lmo2 and Regulates Endothelial Development
Authors: Kweon Junghun , Rasmussen Tara L , Shi Xiaozhong , Wallis Alicia , Bowlin Kathy , Kyba Michael , Koyano-Nakagawa Naoko , Garry Daniel J
Published: April 2024

During early embryonic development, mesodermal progenitor cells give rise to multiple lineages including the cardiovascular, endothelial and hematopoietic lineages. Studies suggest that the extraembryonic yolk sac is a progenitor source for endothelial and hematopoietic lineages during embryogenesis. We have previously shown that Ets related protein 71(ER71) regulates the development of endothelial and hematopoietic lineages in the early yolk sac and embryo proper utilizing an ER71 gene knock out mouse model, an ER71 promoter driven EYFP-expressing transgenic mouse model and an doxycycline-inducible ER71-overexpressing ES/EB model. To decipher the ER71 mediated mechanism for lineage specification, we evaluated candidate downstream targets of ER71 using qPCR, transcriptome analysis, ChIP and transcriptional assays in the ER71 global gene knockout mouse and doxycycline inducible ER71 overexpressing ES/EB models. Using qPCR, we observed an absence of hematopoietic and endothelial restricted genes in the ER71 mutant yolk sacs and embryo proper compared to their wildtype littermates. We further observed a significant downregulation of Lmo2 in the mutant embryo compared to the wildtype control. Moreover, forced overexpression of ER71 using an inducible ES/EB system revealed that Lmo2 was significantly upregulated within 12 hours following ER71 induction. Analysis of approximately 100kb of the Lmo2 gene revealed multiple potential Ets binding motifs and evaluation of each of these sites using ChIP assays focused our efforts on the 1 kb region in the first intron of the Lmo2 gene. Using an array of biochemical techniques including EMSA, transcriptional assays and mutagenesis our data collectively support the hypothesis that Lmo2 is a direct downstream target of ER71. In summary, the present studies define an ER71-Lmo2 transcriptional network that governs endothelial specification and differentiation during cardiovascular development.
Abstract 16788: Platelet Distribution Width is an Independent Predictor of All-Cause and Cardiovascular Mortality Among Healthy US Adults
Authors: Qayyum Rehan , Vaidya Dhananjay
Published: April 2024

Background:
Platelets play an important role in pathogenesis of acute coronary syndromes and platelet parameters (platelet count[PC], mean platelet volume[MPV], and platelet distribution width[PDW]) have been proposed as risk factors for cardiovascular disease. Our aim was to examine the association of platelet parameters with all-cause and cardiovascular (CV) mortality in a large US cohort.

Methods:
We used the Third National Health and Nutrition Examination Survey and the data linked to mortality files to examine association between platelet parameters and all-cause and CV mortality. We used Cox proportional hazards model to calculate hazards ratio (HR) and 95% confidence interval (CI) using age as time-scale in 13,701 participants who were > 20 and <85 years and were free of clinical CV disease at baseline.

Results:
There were 2741 all-cause deaths and 1084 CV deaths during the follow-up (median follow-up 14.3 years, range 0 to 18). The mean (SD) age of the participants was 45 (18) years, 54% were females, 40% were Caucasians, 26% were current smokers and 24% had history of hypertension. Mean (SD) PC was 276(71) 10
9
/L, MPV 8.5(1.0) fL, and PDW 16.4% (0.56). Univariate analyses found no association of PC or MPV with all-cause or CV mortality but a significant association with PDW (all-cause mortality HR: 1.12 per unit increase in PDW, 95%CI: 1.03 to 1.21; CV mortality HR: 1.15, 95%CI: 1.01 to 1.31). Similarly, in multivariable analyses after adjusting for sex, race, CRP, diabetes, hypertension, smoking status, glomerular filtration rate, total cholesterol, WBC count, liver function tests, and ferritin, there was no association between PC or MPV and all-cause or CV mortality but the association with PDW remained significant (all-cause mortality HR: 1.16, 95%CI: 1.07 to 1.26 and HR for CV mortality: 1.17, 95%CI: 1.02 to 1.33.

Conclusions:
Among the platelet parameters, we found PDW, and not PC or MPV, as an independent predictor of all-cause and CV mortality. We propose that this test should be routinely reported with other hematological parameters in complete blood count reports.
Abstract 168: Age Alone Is Not a Predictor of Outcome in Post Cardiac Arrest
Authors: Giberson Brandon , Salciccioli Justin , Cocchi Michael , Giberson Tyler , Bivens Matthew , Gautam Shiva , Donnino Michael
Published: April 2024

Introduction:
Age is an independent predictor of morbidity and mortality in most forms of acute illness, including in cardiac arrest. However, the independent effect of age on outcome for a cardiac arrest patient who regains return of spontaneous circulation has not been well examined. We hypothesize that age is not a determining factor in post-cardiac arrest mortality or neurological outcome.

Methods:
We performed an observational cohort study of survivors of cardiac arrest. Data was collected prospectively between 12/2007 and 2/2011. Inclusion criteria: age > 18 years; out-of-hospital or in-hospital cardiac arrest; successful return of spontaneous circulation (ROSC). Traumatic arrests were excluded. Data collected included baseline demographics including age. Outcomes data included neurologic outcome (Cerebral Performance Category) and mortality. We describe the population with simple descriptive statistics including means or medians with standard deviations or interquartile ranges or frequencies with percentages, as appropriate. We performed a univariate logistic regression with age as the independent variable to predict primary (death) and secondary outcome (poor neurologic outcome) and report Odds Ratios with 95% Confidence Intervals.

Results:
A total of 229 patients were analyzed. The median age of the cohort was 70 (IQR: 56 - 79) and 72/229 (31.6%) were female. As a continuous predictor age was neither a predictor of in-hospital mortality (OR: 1.01, 95% CI: 0.99 - 1.03) nor of poor neurologic outcome (OR: 1.01 95% CI: 0.99 - 1.03). When categorized by 5- and 10-year intervals age remained unassociated with mortality (5-year OR: 1.07, 95% CI: 0.99 - 1.16; 10-year OR: 1.14, 95% CI 0.97 - 1.34) or neurological outcome (5-year OR: 1.07, 95% CI: 0.98 - 1.16; 10-year OR: 1.14, 95% CI 0.97 - 1.34).

Conclusion:
As an independent variable, age is a poor predictor of morbidity and mortality in cardiac arrest patients who achieve return of spontaneous circulation. These data suggest that treatment strategies in post-cardiac arrest patients should be executed without regard to age and that age-adjusted analysis in post-cardiac arrest may not be necessary. Validation of this finding in a large cohort of post-cardiac arrest patients is necessary.
Abstract 16802: Gender Match Does Not confer Survival Advantage in Pediatric Heart Transplantion
Authors: Tosi Lee , Halnon Nancy , Federman Myke , Markovic Daniella , Harrison Rick
Published: April 2024

Background:
In adult heart transplant recipients, a survival advantage for male recipients with donor-recipient gender match has been shown. We determined if similar effects of recipient gender, donor gender, and donor-recipient mismatch exist in pediatric heart transplantation.

Methods:
We reviewed the United Network for Organ Sharing (UNOS) database for 3630 first time heart transplant recipients younger than age eighteen years transplanted between January 1994 and May 2008. We determined mortality rates based on recipient gender, donor gender, and donor recipient gender match with and without adjustment for known risk factors, including presence of congenital heart disease, assist device, race, donor or recipient age, era, elevated bilirubin or creatinine, mechanical ventilation, and dialysis.

Results:
Female recipients (F) had increased mortality compared to male recipients (M) with adjusted hazard ratio (HR) = 1.27 (1.12-1.44, p < .001). Donor gender had no effect on mortality. Gender mismatch conferred no survival disadvantage for male recipients with adjusted HR = 1.09 (0.92-1.29, p= .330) nor female recipients with HR= 1.12 (0.93-1.36, p=0.330). The largest survival effect was between M to M and M to F groups (HR=1.38; 1.17-1.63, p< .001). However, 5 year conditional survival was similar between all groups (M to M, F to F, M to F, F to M) (log rank p =.1077 for 30 day and p=.0595 for 1 year survivors).

Conclusion:
In pediatric heart transplant recipients, unlike adult patients, gender match does not confer survival advantage. Female recipients have increased mortality compared to male recipients. Gender specific recipient risk factors post transplant should be investigated.
Abstract 16812: Bone Morphogenetic Protein Signaling is Required for Vascular Calcification in a Murine Model of Matrix GLA Protein Deficiency
Authors: Malhotra Rajeev , Derwall Matthias , Spagnolli Ester , Beppu Yuko , Shakartzi Hannah R , Buys Emmanuel S , Yu Paul B , Bloch Kenneth D
Published: April 2024

Introduction:
Matrix GLA protein (MGP) is a mineral-binding extracellular matrix protein that is thought to prevent vessel calcification by sequestration of calcium ions. However, MGP also inhibits bone morphogenetic protein (BMP) signaling. MGP
-/-
mice exhibit severe medial arterial calcification by 2 wks and die by 6 wks from aortic aneurysm and rupture. We hypothesized that MGP prevents vascular calcification via its effects on BMP signaling.

Methods:
MGP
-/-
mice were treated with either vehicle or the small molecule BMP type I receptor inhibitor LDN-193189 (LDN, 2.5 mg/kg once daily IP) from day 1 to 28. Whole aortas were harvested for phospho-Smad 1/5/8 (P-Smad) immunohistochemistry, a marker of BMP signaling, and for Alizarin Red staining of calcium. Osteogenic activity in aortas was visualized ex vivo by the uptake of a fluorescent bisphosphonate imaging probe. MGP
-/-
mice were also treated with vehicle or LDN to ascertain if inhibition of BMP signaling could impact survival, using Kaplan-Meier and Cox regression analysis.

Results:
MGP
-/-
aortas demonstrated increased P-Smad compared to wild-type mice. LDN treatment of MGP
-/-
mice reduced aortic P-Smad levels and was associated with a reduction in tissue calcium levels (Fig. A & B). Pharmacologic inhibition of BMP signaling in MGP
-/-
mice resulted in an 81% reduction in aortic osteogenic activity compared to vehicle-treated controls (Fig. C; n=6 in each group; normalized average intensity ± SEM, 0.19 ± 0.05 vs 1.0 ± 0.10, P<0.0001), with similar reductions observed at the aortic arch and the abdominal aorta. LDN treated mice exhibited improved survival compared to vehicle-treated controls (n=10 in each group; Cox hazard ratio 0.04, 95% CI 0.01-0.17, P<0.001).

Conclusions:
MGP prevents vascular calcification primarily via its impact on BMP signaling. Pharmacologic BMP inhibition improves survival in MGP
-/-
mice and may represent an important therapeutic target in the treatment of human vascular disease.
Abstract 16825: Minimizing the Risk for Pericardial Effusion/Tamponade During LA Appendage Closure Using a Next-Generation Watchman LAA Closure Device (Preliminary Results of the European EVOLVE Registry)
Authors: Reddy Vivek Y , Neuzil Petr , Sick Peter , Sievert Horst
Published: April 2024

Introduction:
The PROTECT AF randomized trial compared Warfarin with left atrial appendage (LAA) closure using a filter device (Watchman) in atrial fibrillation (AF) pts with CHADS
2
≥ 1. While the primary endpoint of stroke/systemic embolism/cardiovascular death favored LAA closure (RR = 0.71, 95%CI 0.44 - 1.30), there was a significantly higher risk of safety complications of LAA closure compared to control- the most frequent being peri-procedure pericardial effusion and tamponade. Herein, we report the early experience with a next generation Watchman device designed for less traumatic LAA placement.

Methods:
As compared to the current Watchman device, the distal tines of the next generation Watchman device are designed to deploy in a less traumatic fashion. Implantation with this next generation device was offered to AF patients with a CHADS
2
score of ≥ 1. The device was implanted in standard fashion: IV heparinization, transseptal puncture, TEE guidance. Post-implantation, patients were discharged on 6 weeks of warfarin followed by 4.5 months clopidogrel and life-long aspirin therapy.

Results:
Patients (n=51) were enrolled at 3 centers in Europe: age 70.9 ± 7.4 (56-83), 33% female, CHF in 33%, HTN in 86%, DM in 39%, prior stroke/TIA in 33%, Age ≥ 75 in 45%, CHADS
2
score = 2.7 ± 1.2 (1 - 6). Implantation was successful in 49/51 patients (96%). Currently, mean follow-up is 3.8 months with 5 patients followed to one year. The atraumatic distal end of the device could be inadvertently or purposefully pushed against the LAA tissue without fear of trauma; indeed there were no instances of acute or delayed pericardial tamponade.

Conclusions:
This very early experience reveals that modifications to this next generation WATCHMAN device have rendered it possible to implant without fear of pericardial tamponade.
Abstract 16832: A Protective Role for Toll like Receptor 4 in Pathogen-Mediated Atherosclerosis
Authors: Hayashi Chie , Gudino Cynthia V , Papadopoulos George , Weinberg Ellen O , Barth Kenneth R , Madrigal Andres G , LaValley Michael , Chen Yang , Hua Ning , Gibson Frank C , Hamilton James A , Genco Caroline A
Published: April 2024

Endogenous and exogenous ligands of microbial origin stimulate inflammation associated with atherosclerosis progression via the innate immune Toll like receptors (TLRs). The oral pathogen Porphyromonas gingivalis induces inflammatory oral bone destruction manifested as periodontal disease, a common chronic disease. P. gingivalis-mediated periodontal disease is now recognized as a risk factor for systemic inflammatory diseases including, diabetes, stroke, and atherosclerotic and cardiovascular diseases. We have previously demonstrated that TLR2 deficiency diminished P. gingivalis-mediated atherosclerosis in an ApoE-/-mouse model. In the current study we demonstrate that TLR4 plays a protective role in P. gingivalis induced atherosclerosis. ApoE-/- and Apoe-/-TLR4-/- mice on normal chow diet were orally challenged with P. gingivalis or saline 5 times / week for 3 weeks. Thirteen weeks after the last challenge, plaque and inflammatory cell accumulation was analyzed in aortic tissue. Plaque area (%) and accumulation of macrophages, CD8+ T cells, and IL-17+ cells in aortic plaque were significantly greater in P. gingivalis-infected ApoE-/-TLR4 -/- compared to ApoE-/- mice. TLR4 deficiency was associated with a skewing of the adaptive response to P. gingivalis from a Th1 to a Th17 response with a dysregulation in the production of proinflammatory and immunoregulatory cytokines associated with CD8+ T cell responses. MRA imaging revealed greater luminal narrowing in innominate artery of P. gingivalis-infected ApoE-/- TLR4-/- compared to ApoE-/- mice. Our results are in contrast to studies demonstrating decreased atherosclerosis in ApoE-/-TLR4-/- mice fed a high fat diet. These results support the emerging view that oral bacteria contribute to chronic inflammation at sites distant from infection and establish microbial specific TLR4 signaling as a critical determinant of chronic inflammation associated with atherosclerosis progression.
Abstract 16834: Cardiac and Circulating Levels of MicroRNA-21 Reflect Myocardial Fibrosis in Aortic Stenosis Patients
Authors: Nistal J Francisco , García Raquel , Villar Ana V , Llano Miguel , Cobo Manuel , Expósito Víctor , Martín-Durán Rafael , Hurlé María A
Published: April 2024

Background:
Aberrant expression of microRNAs (miRNA) has been recently associated with various cardiovascular pathophysiological conditions and circulating miRNAs are emerging as promising biomarkers. MiR-21 overexpression has been related to cardiac fibrotic responses to biomechanical stress. The aim of this study was to investigate the clinical value of miR-21, cardiac and plasmatic, as biomarker for pathological myocardial fibrosis progression secondary to pressure overload.

Methods:
In LV biopsies from 17 controls and 39 patients with aortic stenosis (AS), we quantified the expression levels of miR-21 normalized to U6B (qRT-PCR) and determined their relationship with mean transvalvular gradients (continuous wave Doppler) and with myocardial expression of remodeling-related genes (qRT-PCR). Total RNA was isolated from plasma using TRIzol. Spiked-in
C. elegans
-miR-39 was used as control. Reverse transcription was performed using miR-21 and cel-miR-39 specific primers. qRT-PCR was performed with Taqman assays. miR-21 levels were normalized to cel-miR-39.

Results:
Myocardial expression levels of miR-21 were significantly higher in AS patients compared with controls (Control: 115±14 vs AS: 189±26; p<0.05) and correlated directly with the mean transvalvular gradient (R=0.51**). A direct relationship between the myocardial expression levels of miR-21 and the mRNA levels of TGF-β1 (R=0.42, p<0.05), its effectors [SMAD4 (R= 0.44; p<0.05) and TAK1 (R=0.41, p<0.05)] and fibrosis-related target genes [collagen I (R=0.47; p<0.01), collagen III (R=0.58; p<0.001) and fibronectin (R=0.61; p<0.05)] was also observed. Plasma levels of miR-21 were up-regulated in AS patients (Control: 15.0±7.5 vs AS: 182.4±97.8; p<0.05) and correlated directly with the myocardial expressions of SMAD4 (R= 0.57; p<0.01), TAK1 (R=0.51, p<0.01), collagen I (R=0.50; p<0.01) and fibronectin (R=0.41; p<0.05).

Conclusions:
These results support the emerging role of miR-21 as a regulator of the fibrotic process developed in response to pressure overload in AS patients. Our data underscore the value of circulating miR-21 as biomarker of fibrosis with potential prognostic value.
Abstract 16845: Peroxiredoxin 1 Protects DDAH Activity During Oxidative Stress
Authors: Zhang Ping , Xu Xin , Hu Xinli , Fassett John , Chen Yingjie , Bache Robert J
Published: April 2024

Peroxiredoxins (Prdxs) are a family of small nonseleno peroxidases that catalyze the reduction of H
2
O
2
, organic hydroperoxides and peroxynitrite. Prx 1 is the most abundant and ubiquitously distributed member of mammalian Prx. In macrophages, nitric oxide (NO) increases Prx1 expression, inhibits Prx overoxidation, and increases Sulfiredoxin (SRX) expression (SRX is the major macrophage sulfinyl reductase that regenerates oxidized 2-cys Prxs to the active form). DDAH1 is the major enzyme that degrades the endogenous NOS inhibitor ADMA and thereby plays an important role in maintaining normal endothelial function. Using co-immunoprecipitation and mass spectrometry we found that Prx1 binds to DDAH1. On the basis of this finding, we hypothesized that as a result of degrading ADMA, increasing NOS activity and NO production, DDAH1 causes increased SRX expression and regenerates active Prx; the association of Prx1 and DDAH1 could thus protect DDAH1 from loss of activity caused by oxidative stress. In HUVEC, the NO donor DETA-NO (100μM) increased SRX expression and decreased Prx overoxidation (Prx-SO2). Comparing aortic endothelial cells from DDAH1 global KO (KO cells) and wild type control mice (wt cells), we found higher Prx-SO2 levels in KO cells. Furthermore, treatment with ADMA (100 μM) inhibited SRX expression in KO cells but not in wt cells. These results suggest that DDAH1 increases SRX expression, and facilitates regeneration of the Prx active form. Since DDAH1 activity can be inhibited by oxidative stress, we studied the effect of hydroperoxide on the Prx1 and DDAH1 interaction. When we treated HUVEC overexpressing DDAH1 with tert-Butyl hydroperoxide (t-BH 50 μM, 30 min), DDAH activity decreased 15% ± 2.9% (p<0.05), while the level of Prx1 and DDAH1 interaction increased as shown by DDAH1 immunoprecipitation and Prx1 western blot. The findings suggest that under conditions of oxidative stress, increased Prx1 binding to DDAH1 acts to protect DDAH activity.
Abstract 16847: Cardiac Deletion of Liver Kinase B1 Leads to Cardiac Dysfunction, Atrial Arrhythmias and Ultra-Structural Abnormalities That are Not Attributable to AMP-Activated Protein Kinase Inactivation
Authors: Ross Jenna L , Palmeri Monica , Zaha Vlad G , Young Lawrence H
Published: April 2024

Liver kinase B1 (LKB1) is an upstream activator of AMP-activated protein kinase (AMPK) as well as 12 other members of the AMPK superfamily. In order to address the potential role of LKB1/AMPK signaling in cardiac development and growth, we generated cardiac specific LKB1 deleted mice (MHC Cre-LKB1flox/flox) in a pure C57/Bl6 background and compared cardiac size, function, electrophysiology and ultra-structure to syngeneic AMPK kinase-dead (AMPK-KD) mice expressing the rat alpha2 K45R mutation. LKB1 mRNA and protein were reduced by >85% in atria and >95% in ventricles in MHC Cre-LKB1flox/flox hearts. MHC Cre-LKB1flox/flox (n = 6) mice were in sinus rhythm at postnatal day 1, but developed atrial fibrillation by two weeks of age (n = 11); in contrast, LKB1flox/flox (n = 5) and AMPK-KD (n = 6) mice did not develop atrial arrhythmias through 10 weeks. Echocardiography revealed significant left atrial (LA) enlargement by 4 weeks of age (1.95 ± 0.11 mm vs. 1.45 ± 0.19 mm, p<0.05), left ventricle (LV) hypertrophy at 6 weeks of age (0.78 ± 0.03 mm vs. 0.67 ± 0.03 mm, p<0.05), and progressive cardiac dysfunction (LV ejection fraction (LVEF): 40.3 ± 2.1% vs. 48.9 ± 2.3%) in MHC Cre-LKB1flox/flox vs. LKB1flox/flox. In contrast, AMPK-KD (n = 6) vs. AMPK-WT (n = 3) hearts had similar LA diameter (1.51 ± 0.15 mm vs. 1.59 ± 0.05 mm), LV wall thickness (0.67 ± 0.03 mm vs. 0.66 ± 0.03 mm), and LVEF (48.9 ± 2.3% vs 47.8 ± 2.4%). Histological analysis revealed marked atrial fibrosis by two weeks of age in MHC Cre-LKB1flox/flox hearts, but normal morphology in AMPK-KD hearts through 10 weeks. Electron microscopy showed disrupted gap junction formation, mitochondrial integrity and the presence of autophagic bodies exclusively in MHC Cre-LKB1flox/flox hearts. In conclusion, this study indicates marked myopathic and arrhythmic abnormalities in LKB1 deleted vs. AMPK-KD mouse hearts. Thus, AMPK-independent signaling, possibly mediated by AMPK-related kinases, appear to be critical for LKB1 regulated cardiac development and growth.
Abstract 16854: Iodine Deficiency and Risk of Coronary Heart Disease Events Among Low Risk Healthy US Adults
Authors: Zalawadiya Sandip K , Veeranna Vikas , Ramesh Krithi , Neeraj Ashutosh , Afonso Luis , Bagchi Nandalal
Published: April 2024

Background:
Prevalence of iodine deficiency (ID) has increased among general US population. No study has evaluated ID's effect on primary risk of coronary heart disease (CHD) events.

Objective:
Evaluate the relationship between ID and CHD risk

Design:
Cross-sectional

Methods:
We evaluated 10,037 adults, free of cardiovascular disease and diabetes, participating in National Health and Nutrition Examination Surveys . Participants were assigned Framingham risk score (FRS) per Adult Treatment Plan guidelines. Urine iodine levels (mcg/L) were used to define ID per World Health Organization criteria: Group 1 -: None(≥100), Group 2 -: Mild(50-99) and Group 3 -: Moderate-severe(<50). Multivariate regression analysis was performed to analyze the effect of ID on the risk of having higher FRS.

Results:
Mean FRS increased with higher degrees of ID (Group 1: 7.5±8.1 vs Group 3: 9.4±7.4, p<0.001). ID significantly predicted (p<0.001) higher FRS after adjusting for race, body mass index, history of thyroid dysfunction, hemoglobin A1c, high sensitivity C-reactive protein, estimated glomerular filtration rate, serum T4, serum thyroid stimulating hormone and selenium levels [beta co-efficient 0.69(95% confidence interval (CI):0.38-1.00) for group 2 and 1.46(95% CI:1.08-1.84) for group 3 compared to group 1]. Similar results were observed when FRS was evaluated in categories. (Table 1)

Conclusion:
ID is associated with CHD risk independent of thyroid dysfunction and traditional cardiovascular risk factors. Further validation of our study results is warranted since ID is easily remediable through public health policies.
Abstract 16873: A Human Model of Antibody Mediated Arteriosclerosis And Atherosclerosis
Authors: Loupy Alexandre , Lefaucheur Carmen , Vernerey Dewi , Empana jean-Philippe , Glotz Denis , Legendre Christophe , Jouven Xavier
Published: April 2024

Animal models have suggested an association between antibodies (Ab), endothelial cells and the development of arteriosclerosis/atherosclerosis. Our aim was to study the relationship between allo-antibodies and vascular injury in a human model of kidney transplantation where patients Ab levels are monitored and protocol biopsies performed with careful examination of renal cortical arteries. This study included all acute kidney rejection episodes of all 2717 kidney transplantations performed in 2 centers and individualized 302 patients with biopsy-proven acute rejection. We found that among these rejections, 64 patients (22%) had evidence of vascular rejection with donor-specific anti-HLA antibodies, characterized by intimal arteritis with monocytes/macrophages infiltrating the endothelium of arteries. Vascular rejection with antibodies progressed to more severe arteriosclerosis lesions at 1 year post-transplantation as compared to rejection without arteritis (p<0.01). Vascular rejection with anti-HLA antibodies and high grade arteritis showed lipid accumulation in arteries that was not observed in rejections without Ab. Vascular rejection with Ab was associated with the highest risk of graft loss (Hazard Ratio [HR]=9.7 vs T cell mediated rejection, p<0.01). Among the determinants of vascular rejection prognosis, the multivariate analysis demonstrated that high level of allo-antibodies (HR=3.8, p=0.029) was associated with a bad graft outcome whereas the use of antibody targeting strategy (steroids/Plasma-exchange/anti-CD20) was independently associated with improved graft prognosis (HR=0.19 vs steroids±[OKT3/Thymoglobulin], p<0.03). In conclusion, we used here a population of kidney transplantation as a unique human model to study the effects of antibodies in vessels. Using a large cohort of patients with biopsy proven rejections, we identified a new entity of antibody-mediated arteritis that promotes acceleration of arteriosclerosis and atherosclerosis. This model may provide new insights to the pathophysiology and the therapeutic options of arteriosclerosis and atherosclerosis diseases.
Abstract 16874: Predictors of Major Adverse Cardiac Events in Renal Transplant Recipients
Authors: Aftab Waqas , Rasool Shuja , Varadarajan Padmini , Pai Ramdas G
Published: April 2024

Background:
Renal transplantation has become the treatment of choice in end stage renal disease patients. Though the incidence of acute myocardial infarction is reduced after kidney transplant as compared to patients awaiting kidney transplant, major adverse cardiac events (MACE) are still common after renal transplant, especially in early post operative period.

Methods:
We reviewed medical records of 321 consecutive adult patients from our institution who received renal allograft transplantation between1995 and 2003. Details on cardiac risk factors, medications, stress test results, coronary angiogram and coronary intervention were collected and related to MACE.

Results:
The characteristics of 321 patients were as follows: age at transplant 49±13 years, 40% male, 37% diabetics, 87% with hypertension, LV ejection fraction 58±17%. MACE occurrd in 21 patients with cumulative MACE rate of 6.5% over the 3 years after renal transplant, most of them (57%) occurring within 30 days, 67% within 90 days and 84% within 180 days. MACE was not predicted by any of the clinical or pharmacological variables including age, gender, hypertension, diabetes, prior myocardial infarction, smoking, duration of dialysis, LV ejection fraction, or therapy with beta blockers, angiotensin converting enzyme inhibitors or calcium channel blockers. However, a clinical decision to perform a stress test or a coronary angiogram was predictive of a higher MACE rate. The MACE rate was 12.3% in the group with positive stress tests (n=65), 6.1 % in those with negative stress tests (n=134), and 4.1% in the those not referred for a stress test (n=122) (p=0.03). Patients who underwent pre-transplant coronary angiography (n=91), regardless of coronary anatomy, had a higher MACE rate (11 vs 4.8%, p=0.04) than those who did not undergo coronary angiography (n=230).

Conclusions:
(1) The MACE rate following renal transplantation decreases exponentially over time, most occurring in the first 90 days and is not predicted by any of the traditional risk factors or drug therapies. (2) However, a clinical decision leading to a stress test or coronary angiography and stress test positivity are highly predictive of a higher MACE rate.
Abstract 16897: Morphologic and Functional Assessment of Coronary Artery Disease: Potential Application of CT Angiography and Myocardial Perfusion Imaging
Authors: Motoyama Sadako , Sarai Masayoshi , Inoue Kaori , Kawai Hideki , Harigaya Hiroto , Ito Hajime , Takada Kayoko , Naruse Hiroyuki , Ishii Junichi , Narula Jagat , Ozaki Yukio
Published: April 2024

Purpose:
Now that the technological advances have substantially and favorably allowed reduction in radiation burden both from CT angiography (CTA) and myocardial perfusion imaging (MPI) by single-photon emission computed tomography (SPECT), and because CT-SPECT combination is becoming a mainstream investigative tool, we evaluated the role of combined evaluation of MPI and CTA in coronary artery disease (CAD). For CTA, we evaluated both, the extent of luminal stenosis as also the features of high-risk plaques (HRP, including positive remodeling and low attenuation.

Methods:
280 patients (65±11 years, mean f/u: 26 months) underwent both CTA and MPI. Patients without significant stenosis on CTA, or suspected of stenosis by CTA but normal MPI findings were classified as normal, and patients with significant CTA stenosis and reversible defect on MPI were classified as abnormal. On CTA, HRP was also reported regardless of luminal stenosis. Patients were classified into group 1: abnormal CTA and MPI (n=81), group 2: normal CTA and MPI but with HRP (n=25), and group 3: normal by CTA and MPI and also no HRP (n=174). Cardiac events were defined as percutaneous coronary intervention (PCI) or bypass surgery (CABG) after CTA and MPI, and unexpected coronary event.

Results:
Cardiac event was observed in 56 patients; 43 PCI or CABG, and 13 unexpected events. CTA+MPI showed higher diagnostic accuracy than CTA or MPI (sensitivity, specificity, positive (PPV) and negative predictive value (NPV) were 89, 44, 28, 94%, 83, 69, 37, 91%, and 70, 81, 48, 92%, respectively). The prognosis of group1, 2, and 3 were significantly different (logrank: p<0.0001) (figure). Unexpected events were also more frequent in group1 and 2 than group3 (9%vs16%vs1%, p=0.0006).

Conclusion:
The combination of CTA and MPI was more accurate than MPI alone for risk stratification in patients suspected CAD. Furthermore, plaque detection by CTA would be the additional valuable information to predict the cardiac event.
Abstract 16902: Quantification of Coronary Flow Reserve in Normal Subjects Using Regadenoson Vasodilator Stress Real-Time Contrast Echocardiography: A Feasibility Study
Authors: Abdelmoneim Sahar S , Hagen Mary E , Mendrick Edward , Pattan Vishwanath , Wong Benjamin , Norby Barbara , Roberson Tamara , Szydel Troy , Basu Rita , Basu Ananda , Mulvagh Sharon L
Published: April 2024

Background:
Regadenoson is a selective A2A receptor agonist that is administered as a fixed dose bolus with rapid onset (∼30 sec), and short duration (∼2-4 min) of action. The aim of this study was to evaluate the feasibility of real-time myocardial contrast echocardiography (MCE) for quantification of coronary flow reserve (CFR) in healthy humans during regadenoson vasodilator stress.

Methods:
Fifteen subjects [3 males, age: 45.8±5.2 years, BMI 23.8±2.3 kg/m2] with normal LV wall motion and no CAD underwent real-time MCE. Three standard apical LV views were acquired during a continuous intravenous (IV) infusion of Definity (1.3 ml in 60 cc 0.9% saline at 200 ml/hr) at rest and during vasodilator stress (regadenoson 400 ug IV bolus). Following transient microbubble destruction, microbubble velocity (β, sec
-1
), myocardial blood volume (A, dB) and myocardial blood flow (MBF, dB/sec) were determined. Videodensitometric quantification using a 16-segment model at end-systole was performed off-line.

Results:
Quantification of reserve parameters was feasible in all (15/15) patients, 188/240 segments (78%)[82%, 80% and 70% of 4-, 2-, 3-chambers apical views] and 43/45 (95%) coronary territories [one each of Cx and RCA territories were not feasible]. Augmentation from baseline to vasodilator stress was observed for both ß (s
-1
) [0.65± 0.25 vs 0.79± 0.21, P=0.031] and MBF (dB/sec) [2.85± 1.43 vs 4.65± 2.06, P= 0.002], however A (dB) did not change [06.62± 2.57 vs 6.79±2.1, P=0.463]. CFR measurements from all views were similar (Fig 1). There was no significant difference between CFR measured in the 3 coronary territories, although some heterogeneity was noted in the posterior circulation CFR (Fig 2).

Conclusion:
Real-time MCE during Regadenoson vasodilator stress is feasible, and is a useful technique for the rapid noninvasive quantification of CFR in healthy humans.
Abstract 16915: Preoperative Risk Assessment of Patients with Advanced Heart Failure Evaluated for Cardiac Transplantation to Predict Survival Following Heart Transplantation
Authors: Schulze P. Christian , Jiang Jeffrey , Yang Jonathan , Cheema Faisal , Farr Maryjane , Naka Yoshifumi , Mancini Donna
Published: April 2024

Background:
Heart transplantation (HTx) is the only curative treatment of patients with advanced heart failure (HF) but is of limited availability due to severe organ shortage. Appropriate candidate selection is crucial for successful outcomes following cardiac transplantation. We, therefore, analyzed preoperative factors of patients undergoing HTx in order to define clinical factors that would allow risk stratification of patients evaluated for HTx.

Methods:
We retrospectively analyzed 769 patients undergoing HTx at Columbia University Medical Center between 1999 and 2010. Preoperative laboratory values at the time of HTx, medical history, donor characteristics, perioperative clinical events and postoperative outcome were collected from electronic medical records. Survival was confirmed using the social security death index and clinical follow-up at our center. Univariate and multivariate proportional hazard ratios were calculated for 61 individual characteristics to identify factors associated with short and long-term survival after HTx. Significant factors were summarized in a prognostic scoring system for the prediction of survival after HTx. The predictive power of this system was validated in the United Network of Organ Sharing (UNOS) dataset (n=29,734).

Results:
Our analysis identified liver dysfunction (albumin<3.5 mg/dL or total bilirubin>1.3 mg/dL) and renal dysfunction (GFR<40 ml/min), re-HTx, prior stroke or cancer, amyloid, diabetes mellitus, age>65 yrs and more than 2 prior thoracic surgeries with sternotomy as factors associated with poor survival following HTx. The prognostic risk score derived from these factors effectively stratified high risk (4+ points) versus low risk (0-3 points) patients in regard to survival following HTx (86.2% vs. 77.8% at 1-yr and 74.3% vs. 55.9% at 5-yrs post-HTx; p<0.001). These findings were validated and confirmed in the UNOS dataset (88.2% vs. 83.5% at 1-yr and 74.2% vs. 67.2% at 5-yrs post-HTx; p<0.0001).

Conclusion:
Survival of patients following HTx may be improved by use of this noninvasive risk-stratification model for the selection of transplant candidates.
Abstract 16918: Autologous Tissue Engineering Scaffolds for Cellular Cardiomyoplasty
Authors: Chan Angel , Higuichi Takahiro , Sun Dongdong , Strehin Iossif , Lin Xiaoping , Lu Qiaozhi , Armstrong Patrick , O'Rourke Brian , Elisseeff Jennifer , Abraham Maria Roselle
Published: April 2024

BACKGROUND:
Cellular cardiomyoplasty for treatment of cardiomyopathy is limited by low levels of acute retention (∼20%) of transplanted stem cells in the myocardium which results in low long term engraftment (<5%), causing marginal functional benefit.

OBJECTIVES:
To design a biocompatible and biodegradable autologous hydrogel scaffold for improving acute retention, preventing anoikis/apoptosis, and increasing engraftment.

METHODS:
Hydrogel scaffolds were prepared by cross-linking modified hyaluronic acid (HA) with polyethylene glycol (PEG), autologous blood (Bl) or serum (Ser). Cardiosphere-derived cells (CDCs) were isolated from syngeneic, male Wistar Kyoto rats. Cell viability and integrin activation in scaffolds were examined by 2-photon microscopy. Glucose (
18
FDG) uptake of CDC in scaffolds was measured to assess cellular metabolic status, and compared with
18
FDG uptake of suspended and adherent cells. Acute retention rate in the myocardium was determined by
ex-vivo
counting with a gamma-counter and PET/CT imaging after intra-myocardial injection of 1x10
6
18
FDG labeled CDC.

RESULTS:
Hydrogel scaffolds with similar mechanical strength as myocardium (2-4 kPa) were found to be optimal for animal survival. CDC viability in the autologous scaffolds was superior to HA-PEG in the absence of external nutrients with >80 ± 10% vs. 0% viability when cultured in Tyrode for 10 days.
18
FDG uptake of cells encapsulated within various scaffolds was similar to adherent cells, but found to be 9 fold for HA-Bl, 11 fold for HA-Bl:Ser, and 15 fold for HA-Ser (
p
< 0.05) compared with suspended cells. Integrin activation in the cells was observed within 95 ± 2.6% in scaffolds compared to 15.7 ± 8.2% in PBS.

CONCLUSIONS:
Autologous biodegradable tissue engineering scaffolds composed of HA and blood components greatly increased acute CDC retention in the myocardium after intramyocardial delivery. These scaffolds also served as a temporary matrix for cellular attachment and a source of nutrients/growth factors for stem cells survival.
Abstract 16926: Inhibition of Large Conductance K+ Channels (BKCa) Improves Cardiac Functional Recovery Following Cold Hyperkalemic Cardioplegic (CP) Arrest in Isolated Hearts
Authors: Clements Richard T , Cordeiro Brenda , Feng Jun , Bianchi Cesario , Sellke Frank W
Published: April 2024

Introduction:
Cardioplegia during heart surgery subjects myocardium to reversible ischemic injury that impairs cardiac function (a.k.a - “myocardial stunning”). BKCa blockers have established the protective role of BKCa activators for ischemic injury and preconditioning. However, the effect of BKCa blockers alone in the setting of ischemic injury associated with hyperkalemic CP is unknown. Surprisingly, we found that inhibition of BKCa channels, with two distinct BKCa blockers, greatly increased functional recovery following CP.

Methods:
Isolated perfused rat hearts were subjected to 2 hours intermittent cold cardioplegia (St Thomas II) followed by 30 minutes normothermic reperfusion. CP was delivered every 30 min, for 1 min. During CP, hearts were maintained at 10 deg C. Hearts were treated with or without (CP, n=10) the BKCa channel inhibitors paxilline (CP + Pax, 1uM (n=4) and 100 nM (n=4)) or iberiotoxin (10 nM (n=2)) supplied in the cardioplegia. Hearts constantly perfused with KHB served as controls.

Results:
Baseline parameters of cardiac function were similar between groups (mean values: LVDP: 120±5.1 mmHg, ±dP/dt:3298±132, 2465±126). CP reduced cardiac function 30 min post reperfusion (LVDP:61±3.8%,±dP/dt: 67±4.4%, 59±5.1% recovery compared to baseline). Treatment with 100 nM paxilline significantly improved CP-induced reductions in cardiac function (LVDP: 92±4.3%., ±dP/dt: 108±5.6%, 104 ± 6.0% compared to baseline, (p<.01 for LVDP and ±dP/dt, CP+Pax 100 nM vs CP)). Similar results were obtained with both 1 uM paxilline treatment and iberiotoxin. There were no significant changes in heart rate or coronary flow associated with BKCa channel blockade. Paxilline blocked CP-induced phosphorylation of the akt signaling cascade, activation of which is associated with depressed cardiac contractility.

Conclusions:
In contrast to known protective effects of BKCa openers in the setting of ischemic injury, BKCa channel blockers (as a CP additive) profoundly improve cardiac recovery in the context of hyperkalemic cardioplegic arrest.
Abstract 16932: Melatonin Inhibits Large Conductance, Calcium-Activated K Channel Activity in Porcine Coronary Artery Smooth Muscle Cells by Activating MT
2
-Receptors
Authors: Shukla Praveen , Yao Fanrong , Borowicz P , Sun Chengwen , ORourke Stephen
Published: April 2024

Introduction:
Increasing evidence indicates that melatonin plays a role in cardiovascular homeostasis by regulating blood vessel diameter, thereby impacting arterial blood pressure and local blood flow to organs and tissues. Alterations in circulating melatonin levels are associated with several cardiovascular disorders, including hypertension, ischemic heart disease, myocardial infarction, and heart failure. We have shown previously that melatonin impairs nitric oxide (NO)-induced relaxations in porcine coronary arteries by activating melatonin type-2 (MT
2
)-receptors (JPET 336: 127-33, 2011).

Hypothesis:
Melatonin impairs NO-induced relaxation of coronary arteries by inhibiting BK
Ca
channel activity in coronary artery smooth muscle cells (SMC).

Methods and Results:
Sodium nitroprusside (SNP), an exogenous NO-donor, caused relaxation of isolated porcine coronary arteries (-logEC
50
= 7.49 + 0.1; n=5). In the presence of either melatonin (10
-7
M) or iberiotoxin (IbTx; 10
-7
M), a selective BK
Ca
-channel blocker, the SNP dose-response was shifted to the right by approximately 6-fold (p<0.05). The presence of BK
Ca
α- and β-subunits was identified by immunoblot analysis in intact porcine coronary arteries. Immunocytochemistry studies demonstrated that both subunits co-localized with α-actin in isolated single coronary SMC. Whole-cell K currents (10-mV steps from -70mV to +60mV, 200 ms duration) were obtained in freshly isolated coronary SMC in the absence or presence of IbTx (10
-7
M) or SNP (10
-5
M) (n=5-6). IbTx markedly inhibited (p<0.05) both the voltage-dependent activation of whole-cell K currents and the SNP-induced increase in BK
Ca
currents in coronary SMC. Treatment of coronary SMC with melatonin (10
-7
M) inhibited the activation of BK
Ca
currents (56.8 ± 2.9% inhibition of peak current density at +60 mV; n=12; p<0.05) and shifted the I-V curve to the right, as compared to control. The inhibitory effect of melatonin (10
-7
M) on BK
Ca
currents was abolished in the presence of the selective MT
2
-receptor antagonist, 4P-PDOT (10
-7
M).

Conclusions:
Melatonin acts via MT
2
-receptors to inhibit BK
Ca
activity in porcine coronary SMC, suggesting a mechanistic basis for the inhibitory effect of melatonin on NO-induced relaxation.
Abstract 16943: Dissecting the Molecular Interaction of Caveolin3 and the Regulatory Subunit (SUR2) of Cardiac KATP Channels
Authors: Shi Nan , Ye Bin , Ou Jessie , Kamp Timothy , Makielski Jonathan
Published: April 2024

Macromolecular signaling complexes including ion channels present in caveolar microdomains can provide highly specific and localized regulation of cell function. Prior studies have shown that Caveolin3 (Cav3) may interact with a Kir6.2 pore of the cardiac ATP-sensitive potassium channels (KATP). In this report, we studied the molecular interaction of Cav3 and SUR2, the regulatory subunit of KATP. Cav3 and SUR2 were detected in the same caveolar fractions isolated from mouse left ventricles. A P104L-Cav3 mutation was used to probe Cav3-SUR2 trafficking and molecular interaction in COS1 cells. Immunostaining data showed that SUR2 co-localized with Cav3, however, P104L caused retention of SUR2-specific fluorescent signals intracellularly. A quantitative Bioluminescence Resonance Energy Transfer (BRET) assay using coelenterazine-h as substrate was established to study Cav3-SUR2 interaction. WT or P104L-Cav3 was fused to a
Renilla
Luciferase (Rluc) while SUR2 was fused to YFP. Both WTCav3/SUR2 (0.19±0.04, n=10) and P104LCav3/SUR2 (0.17±0.02, n=10, P=0.05) pairs displayed positive BRET ratios, suggesting that the two proteins were within a 10-100 Å distance to permit energy transfer from RLuc (470-nm) to YFP (530-nm). We did not record positive BRET ratios from negative control samples containing no substrate. Our data showed that Cav3 could directly bind to SUR2, and this interaction was not significantly affected by the P104L mutation, indicating that aa104 is probably not a binding site for the two proteins. To determine which portion of SUR2 binds to Cav3, 3 expression clones harboring SUR2 transmembrane domain TMD0, TMD1 or TMD2 were made. BRET results showed that Cav3 preferably binds to TMD0 (0.19±0.01, n=5) or TMD1 (0.15±0.03, n=5) over TMD2 (0.02±0.01, n=5). Co-immunoprecipitation results confirmed our BRET data. Mouse neonatal myocytes infected with adenoviral particles expressing P104LCav3 displayed a significantly prolonged action potential (APD90, 20.5±4, n=6) than WTCav3-expressing cells (9.3±4, n=4, p<0.05), which suggested that Cav3 levels affected membrane electrical properties. Together with other data, a Cav3-SUR2-Kir6.2 complex that resides in the caveolar microdomains may play an important role in cardiac signaling.