bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 17307: Pre-Existing Endoplasmic Reticulum (ER) Stress Inhibits Sars-Co-V2 Entry Into Host Cells Through Modulation of AKT Signaling and Unfolded Protein Response (UPR)
Authors: Bakillah Ahmed A , Al Shaikh Mubarak Sindiyan , Al Otaibi Abeer , Al Hejji Fatimah , Almasaud Abdulrahman , Al Jami Haya , AlSubai Badr , Iqbal Jahangir , Alharbi Naif Khalaf , Al Qarni Ali Ahmed
Published: December 2023

Introduction:
It is well known that SARS-Co-V2 infection can induce ER stress-associated activation of unfolded protein response (UPR) in various host cells which may contribute to the pathogenesis of COVID-19. However, the interplay between SARS-Co-V2 infection and UPR signaling in pre-existing ER stress associated pathological conditions has not been well elucidated.
Hypothesis:
We hypothesized
that modulation of a pre-existing ER stress in host cells could attenuate susceptibility to SARS-CoV-2 infection by activating a range of cellular defense.

Methods:
Increasing concentrations of Tunicamycin (Tm) and Thapsigargin (Tg) have been used to induce ER stress in Huh-7 cells. After 6h treatment, cells were infected with SARS-CoV-2 pseudotyped particles (SARS-CoV-2pp) for 48 p.i. SARS-Co-V2-2pp entry was measured using Bright Glo
TM
luciferase assay. Cell viability was measured by cell titer Glo
®
luminescent cell viability assay. The mRNA and protein expression of UPR markers were evaluated using RT-qPCR and Western blot methods.

Results:
Tm (5 μg/ml) and Tg (1 μM) efficiently inhibited SARS-CoV-2pp entry into cells without any cytotoxic effect. Chemical ER stress-induced inhibition of SARS-CoV-2pp entry was associated with significant reduction of ACE2 expression in Tg-infected cells but not with Tm. Strikingly, Tm and Tg revealed differential effects in modulating the expression of ER stress genes in infected cells. Both Tm and Tg significantly reduced the expression of stress-inducible ER chaperone GRP78/BIP in infected cells. In contrast, the IRE1-XBP1s and PERK-eIF2α-ATF4-CHOP signaling pathways were downregulated in Tg-infected cells only. Additionally, insulin-mediated glucose uptake, phosphorylation of Ser
307
IRS-1 and downstream p-AKT were enhanced in Tg-infected cells without any change in ERK phosphorylation.

Conclusions:
These findings suggest that pre-existing ER stress could modulate a specific UPR response in infected cells capable of counteracting the stress-inducible elements signaling, thereby depriving SARS-Co-V2 of essential components for their entry and replication. Pharmacological manipulation of ER stress in host cells might provide new therapeutic strategies to alleviate SARS-CoV-2 infection.
Abstract 17323: Avoiding Procedural Closure of the Patent Ductus Arteriosus Following Late Acetaminophen Therapy in Preterm Infants
Authors: Dudley Sarah , Wheeler Craig , Morton Sarah U , Khazal Zahara , Mitchell Kaylyn , Horn Elyssa , chamberlain kimberly , Friedman Kevin G , Farias Michael , Porras Diego , Levy Philip T
Published: December 2023

Introduction:
Management of a hemodynamically significant patent ductus arteriosus (hsPDA) in preterm infants beyond 3 weeks of age continues to be a debate. Clinical equipoise exists between pharmacologic agents versus procedural closure techniques (surgical ligation or transcatheter occlusion). The efficacy of acetaminophen for early closure of hsPDA has been demonstrated, but there remains a paucity of data for late closure.

Hypothesis:
To test the hypothesis that late administration of acetaminophen for a hsPDA is associated with reduced rates of procedural closure in preterm infants.

Methods:
We performed a post-hoc analysis of preterm infants (<37 weeks) referred to Boston Children’s Hospital for ongoing management of a hsPDA from January 2019 to January 2023. We compared neonates with a hsPDA exposed and not exposed to acetaminophen at > 3 weeks of age. The primary outcome was avoidance of procedural closure. We assessed for predictors of closure following acetaminophen therapy.

Results:
We identified 110 preterm infants (median gestational age of 25 weeks at birth) referred for closure of a hsPDA beyond 3 weeks of age (Fig). Late acetaminophen was used in 26 patients (median postnatal age of 31 days). Late acetaminophen was associated with higher rates of non-procedural PDA closure 10/26 (38%), compared to 6/84 (7%) of infants who did not receive late acetaminophen (OR 0.12, CI 0.04 - 0.39, p < 0.01). Presence of flow reversal in the descending aorta was associated with lower likelihood of PDA closure with late acetaminophen (OR 0.09, CI 0.01 - 0.85, p=0.017).

Conclusions:
This study found that preterm infants with a hsPDA treated with late acetaminophen had a decreased need for procedural closure. Infants who responded were less likely to have flow reversal in the descending aorta, suggesting that consideration of a course of late acetaminophen prior to procedural closure of a hsPDA in preterm neonates should be selective and based on patient-specific risk factors.
Abstract 17330: Demographic Factors Associated With Disparity in Radial Artery Usage in Coronary Artery Bypass Graft Surgery: Insights From the National Inpatient Sample
Authors: Luo Qianyun , Li Renxi , Huddleston Stephen
Published: December 2023

Introduction:
The choice of graft for revascularization in coronary artery bypass grafting (CABG) impacts surgical outcomes. While both radial artery (RA) and greater saphenous vein (GSV) are options for secondary conduits to the left internal mammary artery (LIMA), RA graft usage is associated with better patency and better long-term survival benefit. However, equity of RA conduit usage in CABG is unknown. This study aimed to examine demographic factors associated with disparity of RA grafting among patients undergoing CABG.

Methods:
The National Inpatient Sample (NIS) was used to extract patients received who underwent CABG between Q4 2015-2020 based on ICD10-PCS. Patients less than the age of 40 were excluded for congenital heart defects. Preoperative variables include sex, age, race and ethnicity, socioeconomic status (SES), Elixhauser comorbidities, and hospital characteristics. The rate of RA usage with respect to race, sex, and SES was compared, respectively, while all preoperative variables besides the variable of interest were adjusted by multivariable analysis.

Results:
There were 56,318 CABG cases identified in the NIS with 11,708 RA and 44,610 GSV grafting. African American race (aOR 0.78, p<0.01), Hispanic race (aOR 0.83, p<0.01), female sex (aOR 0.53, p<0.01), and lower income (0-25 percentile, aOR 0.78, p<0.01; 25-50 percentile, aOR 0.95, p=0.04) were independently associated with lower rates of RA grafting usage among patients who underwent CABG.

Conclusion:
This study reveals disparities in RA graft usage for CABG, including racial minorities, women, and economically disadvantaged groups who were less likely to receive RA. These findings highlight the need for healthcare equity in choosing the optimal graft conduit in CABG.
Abstract 17332: Length of Diagnosis, Diagnostic Tests, and Referral Patterns of Transthyretin Amyloid Cardiomyopathy Patients in the United States, United Kingdom, France, Germany, Italy, and Spain
Authors: Melinis Niya , Collins Peter , Chung Wei Yen , Hefni Fauziah , ozbey ozan
Published: December 2023

Introduction:
Transthyretin amyloid cardiomyopathy (ATTR-CM) is a rare disease that typically presents with symptoms like those commonly associated with heart failure and is frequently misdiagnosed. Timely diagnosis and treatment are key to a favorable prognosis. This study aims to investigate and compare the length between suspicion of ATTR-CM and confirmed diagnosis, examine the number of diagnostic tests, and explore the referral dynamics in the US versus EU4+UK (United Kingdom, France, Germany, Italy, and Spain) using real-world data among patients diagnosed in 2022.

Methods:
A multi-center online medical chart review of patients was fielded in Q4’2022. Cardiologists and cardiology-focused internists from the US and EU4+UK from hospitals and private practices were recruited and screened for ATTR-CM patient management. A total of 239 physicians (US: 109, EU5: 130) who reported on patients diagnosed in 2022 were included, providing data on 759 patients diagnosed during this period (US: 481, EU5: 278).

Results:
Reported patients in the US experienced a shorter length of time from first suspicion of ATTR-CM to confirmed diagnosis, on average, than those in the EU4+UK (p<0.01); US: 6.3 weeks (n=392), EU4+UK: 9.6 weeks (n=205). The average number of tests ordered to diagnose patients was greater in the EU4+UK than in the US cohort (p<0.01); EU4+UK: 6.8 tests (n=277), US: 5.8 tests. A greater proportion of reported patients in the US (p<0.05) first presented their symptoms prior to diagnosis to the reporting physician (35.1%) than those in EU4+UK (27.3%). In the US, 88.4% of the patients were diagnosed by the reporting physician (n=481), whereas in EU4+UK (n=278) this rate was 78.1% (p<0.01).

Conclusions:
This study demonstrated that it took significantly less time to diagnose patients in 2022 in the US than in the EU4+UK. Patients in the EU4+UK were more likely to present symptoms to and be diagnosed by a physician other than the reporting physician, with a greater number of diagnostic tests ordered compared to those in the US. Further investigation using comparator cohort and to discover if there is a difference in patient outcomes is warranted.
Abstract 17334: Association of BIN1 Deletion With Electrical and Structural Remodeling in a Transgenic BIN1 KO Mouse Model of Heart Failure-Novel Option for Effective Therapy Using VK-II-86
Authors: Barajas-Martinez Hector , Westreich Roi , Sedano Summer Mari-Reilly , Robinson Victoria , Cadogan John-Luke , Acuna Jose , Alvarado-Cervantes Maria , Antzelevitch Charles N , Prendergast George , Ashton Anthony , Laury-Kleintop Lisa
Published: December 2023

Introduction:
Cardiac deletion of Bridging Integrator 1 (BIN1) membrane protein produces an age-related cardiomyopathy in mice. Our hypothesis was to determine whether electrical accompanies this structural remodeling and examine the utility of VK-II-86, a structural analog of carvedilol with minimum β-blocking activity, as a potential antiarrhythmic therapeutic strategy.

Methods:
A cardiac-specific transgenic BIN1 KO mouse was employed. Structural and electrical cardiac changes were assessed using echocardiography and EKG (Visual Sonics-Vevo Heart Image). Murine ventricular cardiomyocytes were studied using patch-clamp techniques to examine changes in ion channel function and to study the effects of VK-II-86 on the action potential (AP).

Results:
Loss of BIN1 (KO) significantly reduced Left Ventricular Ejection Fraction (LVEF) and Cardiac Output (CO) when compared to WT mice, with a relative reduction of nearly 20% and 35% in EF and CO, respectively. Heterozygotic mice (HET) also exhibited significant reduction in EF and CO compared to WT mice. Loss of BIN1 (KO and HET) significantly prolonged the QT interval on surface ECG by approximately 15%. This finding correlates with the increase in AP duration (APD) demonstrated in ventricular cardiomyocytes using current clamp. BIN1 deficient hearts displayed significant reduction in expression of I
to
, I
K1
and peak I
Na
(80%, 40% and 20% respectively) as well as augmented expression of late I
Na
(50%). This electrical remodeling is likely responsible for the increased expression of early (EAD) and late (DAD) afterdepolarization observed in APs. In BIN1 deficient ventricular cardiomyocytes, the addition of 1 μM VK-II-86 prevented the development of APD prolongation and suppressed EAD and DAD development.

Conclusions:
Our study adds to the understanding the role of BIN1. We demonstrate the first-time electrical remodeling in the form of QT and APD prolongation associated with BIN1 deficiency, due to reduced I
to
and I
K1
and increase in late I
Na
, an increase in EAD and DAD events. Additionally, VK-II-86 is shown to normalize APD in isolated cardiomyocytes and suppress afterdepolarization events, making it a potentially novel and effective therapeutic strategy in HF associated with BIN1 deficiency.
Abstract 17344: Risk Factors for Disease Severity in Cardiac Laminopathy
Authors: Garmany Ramin , Neves Raquel , Gluscevic Martina , Siontis Konstantinos , Pereira Naveen L , Ackerman Michael J , Giudicessi John
Published: December 2023

Introduction:
Disease-causative variants in
LMNA
-encoded lamin A/C cause a penetrant dilated cardiomyopathy associated with conduction disease (CD) and ventricular arrhythmias (VA). Prior studies show conflicting results regarding the effect of sex, variant type, and CD on severity and sudden death risk in cardiac laminopathy.

Methods:
In this retrospective study, we utilized a single-center genetic arrhythmogenic cardiomyopathy registry (N=432) to identify patients with ultra-rare
LMNA
variants and ascertain the effect of sex, mutation type, and clinical presentation on disease severity. Advanced heart failure (AHF) events were defined as ventricular assist device placement or cardiac transplantation whereas VA events were defined as sudden cardiac arrest, sustained ventricular arrhythmia, or appropriate implantable cardioverter-defibrillator shock.

Results:
The
LMNA
variant-positive cohort (N=83) had an age of diagnosis of 36 ± 10 years with 80% showing a cardiac phenotype. No difference in the age at diagnosis (37 vs. 34 years; p=0.3) or prevalence of AHF events (14% vs. 18%; p=0.8) and VA events (34% vs. 36%; p=0.9) was observed between females (N=50) and males (N=33). Furthermore, there was no difference in age of diagnosis (37 vs. 33 years; p=0.1) or prevalence of AHF (14% vs. 12%; p=0.9) and VA events (33% vs. 34%; p=0.9) between individuals with missense (N=42) or frameshift (N=32) variants. Interestingly, in comparison to individuals that presented with isolated CD (N=11) those that first presented with left ventricular dysfunction or arrhythmias (atrial or ventricular) (N=41) were more likely to have VA events (9% vs. 53%; p=0.01) and AHF events (0% vs 29%; p=0.05). In addition, those with structural/arrhythmic presentation had earlier time to VA events (15 years vs. 22 years; p=0.04) and AHF events (23 vs undefined; p=0.09) than those with CD.

Conclusions:
Contrary to prior studies, in this large single-center cardiac laminopathy study, sex and mutation type were not associated with increased risk of AHF or VA events. However, patients presenting with isolated CD had a lower risk of AHF and VA events. Contemporary multi-center studies are needed to better ascertain risk factors associated with AHF and VA events in cardiac laminopathy.
Abstract 17356: Recurrent Hemorrhagic Pericardial Effusion Requiring a Multimodality Imaging Approach: A Case Report
Authors: Kalluri Aravind , Chukwurah Marius I , Cappola Tom , Litwack Andrew
Published: December 2023

Background:
A 24-year-old female with no medical history presented to the ED with chest pain and dyspnea. Vitals were notable for tachycardia to 120s. Physical examination was unremarkable.

Clinical Course:
Initial evaluation was notable for thrombocytopenia, NT-proBNP of 151 and high sensitivity troponin T of 18. Transthoracic echocardiogram (TTE) revealed a small pericardial effusion with tamponade physiology prompting urgent pericardiocentesis. Bloody pericardial fluid was drained and fluid studies were consistent with hemorrhagic effusion with no evidence of infection or malignancy on cytology. Surveillance TTEs showed rapid reaccumulation of pericardial fluid within 72 hours of the initial intervention. Urgent pericardial window with drain placement was performed and intraoperative transesophageal echocardiogram (TEE) revealed a right atrial (RA) mass not detected on prior TTE. Cardiac MRI confirmed the presence of a large (50 mm x 31 mm) immobile and heterogeneous mass in the superior aspect of the RA suggestive of a malignant etiology with invasion to the adjacent pericardium. Positron Emission Tomography (PET) scan demonstrated hypermetabolic activity concerning for malignancy with no evidence of mediastinal, hilar adenopathy, or distant disease. She underwent mini-sternotomy and biopsy with pathology suggestive of primary cardiac angiosarcoma. Due to the high-risk nature and location of the tumor, she was unable to undergo primary surgical resection. Neoadjuvant chemotherapy was initiated with plan for subsequent surgical reassessment.

Conclusion:
Workup of recurrent hemorrhagic pericardial effusions require a multimodal imaging approach.
Abstract 17363: Loss of Skeletal Muscle
Bmal1
Impairs Limb Perfusion and Muscle Regeneration in a Mouse Model of Peripheral Arterial Disease
Authors: Zhu Pei , Chao Calvin , Steffeck Adam W , Dang Caitlyn , Jiang Bin , Peek Clara
Published: December 2023

Introduction:
Peripheral arterial disease (PAD) is a growing pathologic condition worldwide and leads to severe myopathy. Traditional risk factors for PAD, including diabetes, smoking, and advanced age, are associated with disrupted circadian clock function. However, the contribution of circadian disruption to PAD remains poorly understood.

Hypothesis:
This study aims to investigate the role of skeletal muscle clock in the severity of PAD.

Methods:
We performed femoral artery ligation (FAL) surgery in male adult-life inducible skeletal muscle-specific
Bmal1
knockout (

Bmal1
musc

) (n = 6) and control mice (n = 5). We measured limb perfusion with laser doppler imaging weekly and assessed post-surgical angiogenesis with CD31/αSMA co-immunostaining and muscle recovery with hematoxylin and eosin (H&E) staining and Laminin immunohistochemistry at 30 days post-surgery. We also performed RNA-sequencing, qPCR, and Western blotting assays to characterize the differentially expressed genes in both ligated and non-ligated hindlimb muscles.

Results:
Adult-life deletion of skeletal muscle
Bmal1
reduced reperfusion recovery, with an average rate of only 50% by 22 days post-surgery in

Bmal1
musc

mice compared to approximately 80% in control mice. HIF1α target genes including the pro-angiogenic factor
Vegfα
were significantly downregulated in

Bmal1
musc

mice. Conversely, genes enriched in the anti-angiogenic TGF-β signaling pathways were up-regulated in

Bmal1
musc

mice. Myostatin, a myokine that inhibits muscle growth, was downregulated in

Bmal1
musc

muscles. H&E staining and Laminin immunohistochemistry revealed significantly less but enlarged newly formed myofibers in the tibialis anterior muscle in

Bmal1
musc

mice.

Conclusions:
Skeletal muscle BMAL1 plays a critical role in determining the severity of ischemic muscle injury in a mouse model of PAD. Circadian dysfunction impairs hindlimb ischemia reperfusion, decreases the number of newly formed myofibers, and promotes the formation of enlarged regenerating myofibers, which is however previously reported to be associated with compromised muscle force production. Restore muscle circadian function could be a promising strategy to ameliorate myopathic severity in PAD patients.
Abstract 17370: Activation of Endothelial GCN2 Kinase Contributes to Pulmonary Vascular Remodeling and Pulmonary Arterial Hypertension
Authors: Zhu Maggie M , Dai Jingbo , Peng Yi , Zhao Youyang
Published: December 2023

Rationale:
Pulmonary arterial hypertension (PAH) is characterized by progressive increase of pulmonary vascular resistance and pulmonary vascular remodeling that result in right heart failure. Published studies show that recessive mutations in the
EIF2AK4
gene (encoding GCN2, General control nonderepressibe 2 kinase) resulting in reduction of GCN2 are linked to heritable pulmonary veno-occlusive disease (PVOD) in patients and
EIF2AK4
mutation was also found in PAH patients although very rare.

Objective:
To determine the role of endothelial GCN2 kinase in the pathogenesis of PAH.

Results:
Employing

Eif2ak4
-/-

mice, we found that loss of GCN2 induced neither spontaneous PVOD nor pulmonary hypertension (PH). In response to chronic hypoxia, loss of GCN2 inhibited hypoxia-induced PH and pulmonary vascular remodeling. RNA-sequencing analysis of mouse lung samples indicated Endothelin-1 as the downstream target of GCN2 in regulating pulmonary vascular remodeling and PH. In cultured human lung microvascular endothelial cells, GCN2 was phosphorylated and activated in response to hypoxia, which mediated hypoxia-induced Endothelin-1 expression through the GCN2/ATF4/HIF-2a/Endothelin-1 pathway. Endothelial cell-targeted nanoparticle delivery of plasmid DNA expressing Endothelin-1 selectively in endothelial cells in

Eif2ak4
-/-

mice markedly reversed the phenotype in response to hypoxia. Furthermore, nanoparticle delivery of the CRIPSR/Cas9 system-mediated knockout of Eif2ak4 in adult C57BL/6 mice also attenuated hypoxia-induced PH. Additionally, monocrotaline-induced vascular remodeling and PH in rats were inhibited by GCN2 inhibitor A-92 treatment. In lung samples of idiopathic PAH patients, we observed endothelial GCN2 hyperphosphorylation of pulmonary vascular lesions, without marked differences in GCN2 mRNA and protein levels compared to normal donor lungs.

Conclusion:
These studies demonstrate that endothelial GCN2 activation mediates pulmonary vascular remodeling and PAH development through the GCN2/ATF4/HIF-2a/Endothelin-1 pathway. Targeting GCN2 signaling is a promising therapeutic strategy for treatment of PAH in patients without GCN2 loss of function mutations.
Abstract 17376: Comprehensive Quantitation of Cardiac Tissue Derived Extracellular Vesicles Regulating Adipose Tissue Metabolism
Authors: Pennise Jennifer L , Yuko Antonia , Harlamova Daria , Mohsin Sadia , Recchia Fabio A , Khan Mohsin
Published: December 2023

The heart is considered as a recipient of signals from the periphery to fine tune blood pumping in response to physiological and pathological changes. Cardiac secretory function consisting of proteins termed as cardiomyokines has founded the concept of
heart mediated organ crosstalk
. Studies have shown extracellular vesicles (EVs) are major players regulating organ crosstalk between peripheral organs and the heart. Nevertheless, whether cardiac tissue derived EVs with unique composition deliver messages to peripheral organs remains unknown. Paired serum samples isolated from coronary sinus (CS) and aorta (AO) of dogs under normal and tachypacing induced heart failure were used for EV isolation, characterization and miRNA array analysis. Transplantation of EV from CS and AO samples under normal and heart failure conditions in wild type mice was done to determine whole body metabolism by CLAMs and modulation of adipose tissue metabolism together with in vitro functional assay in cultured adipocytes. Results showed heart failure promotes increased secretion of EVs in the CS compared to AO blood suggesting heart produces more EVs under diseased conditions. miRNAs array analysis identified top elevated miRNAs as miRNAs 16, 92 and 137 significantly enriches in CS EVs under heart failure conditions. Measurement of miRNAs 16, 92, 137 is different tissues showed significantly increased expression in brown adipose tissue (BAT) compared to all other tissues assessed. Next, 3TC-LI adipocytes treated with CS EVs from heart failure dogs showed decreased OXPHOS measured by Seahorse, reduced expression of mitochondrial markers and low BODIPY labelling together with increase in whole body oxygen consumption rates, food intake and energy expenditure as measured by CLAMS. Mechanistically, EV derived miRNAs 16, 92, 137 significant transcriptomic changes BAT assessed by bulk RNA-sequencing. Top altered genes identified in BAT were UQCR10, CPT1a and PGC1a after administration of CS EVs from heart failure animals and are binding targets for miRNAs 16, 92 and 137 respectively. In conclusion, cardiac tissue communicates to adipose tissue to regulate metabolism by releasing EVs derived miRNAs enriched differently in response to heart failure or under normal conditions.
Abstract 17381: Relationship Between Amaurosis Fugax and Intraplaque Hemorrhage in Patient With Carotid Plaques
Authors: Wiley Karlo A , Anker Allison , Sanina Cristina , Kozdag Gold Guliz
Published: December 2023

Introduction:
The term amaurosis fugax is often used interchangeably to describe transient visual loss. However, it is employed widely in medicine to refer to any cause of transient monocular visual loss. Amaurosis fugax is associated with an imminent stroke and it could be linked to vascular thromboembolic events arising from the internal carotid arterial system. The aims of the study are to determine the plaque characteristics of patients who underwent carotid artery revascularization and the relationship of plaque characteristics with amaurosis fugax.

Methods:
Before elective carotid revascularization 44 patients (mean age 72±8 years; 25 males, 19 females) underwent 3-T MRI. After localization of the carotid bifurcation using phase contrast imaging, Time-of-Flight, 3D T1 weighting, transverse T1 and T2 weightings and proton density sequences were acquired. The different plaque components: lipid rich core, intraplaque hemorrhage, calcification and the characterization of the fibrous cap were assessed.

Results:
Carotid plaque samples had the following characteristics: Intraplaque hemorrhage (59%), surface defects (38.6%), stable fibrous cap (27.3%), lipid rich necrotic core (18%), and calcifications (11.4%). Amaurosis fugax history was identified in 7 patients (15.9%). Plaque samples from all 7 patients who had experienced amaurosis fugax revealed intraplaque hemorrhage. MRI revealed intraplaque hemorrhage in 19 (51%) patients without history of amaurosis fugax (p=0.016). The rest of the plaque characteristics did not show any statistically significant relationship with history of amaurosis fugax.

Conclusions:
This study demonstrated that intraplaque hemorrhage may be correlated to amaurosis fugax.
Abstract 17386: Pulmonary Vein Stenosis After Pediatric Heart Transplant
Authors: Butto Arene , Ohalloran Conor , Kuo James , Joong Anna , Nugent Alan W , Mahle William T , Tannous Paul
Published: December 2023

Introduction:
Pulmonary vein stenosis (PVS) is a rare condition in which neointimal proliferation of the pulmonary veins leads to venous and arterial hypertension. Little is known about the development of PVS after heart transplant (HTx) in children, which is a rare but known complication of HTx.

Research Question:
To describe the clinical characteristics, progression of disease, and outcomes of children who develop PVS after HTx.

Methods:
We performed a retrospective review of patients ≤18 years old who underwent HTx at two pediatric centers, Children’s Healthcare of Atlanta and Lurie Children’s Hospital, between April 2012-April 2022. Patients with a diagnosis of PVS were identified through queries of PVS databases at each center. Details related to the underlying cardiac diagnosis, location and extent of PVS, and post-HTx outcomes were recorded.

Results:
During the study period, 374 patients underwent HTx across both centers. Seventeen PVS patients (9 male) were identified, 15 of whom had de novo PVS. Fifteen had underlying congenital heart disease (CHD) and 2 had cardiomyopathy. Among CHD patients, 2 had a history of anomalous pulmonary venous return and 14 had prior cardiac surgery. Two patients had undergone catheter based PVS intervention prior to Tx. PVS was diagnosed at a median of 2 months (range 2 weeks-14 years) after HTx. At initial diagnosis, 12 patients had one-vessel PVS, most commonly the left upper pulmonary vein (n=8). At final follow-up, 2 patients had 2-vessel PVS and 7 had 3-4 vessels involved. Surgical intervention was required in 8 unique patients, most commonly for the left veins. Stent or balloon angioplasty were used in all left-sided veins, most commonly in the left lower pulmonary vein (n=8). Two patients were medically treated for pulmonary hypertension following PVS diagnosis. There were 3 deaths in the cohort, 2 of which were thought to be caused by right heart failure secondary to PVS.

Conclusions:
This is the first study to describe the characteristics of post-HTx PVS in children. PVS occurs in 4.5% of HTx and history of CHD is a strong risk factor. Multiple vessels can be involved and may require catheter-based or surgical intervention. Clinicians must be vigilant in monitoring for the development of PVS in this population.
Abstract 17394: Minimally Invasive Delivery of Synthetic Cardiac Stromal Cells Improves Heart Repair in Pigs
Authors: Li Yuan , Huang Ke , Cheng Ke
Published: December 2023

Introduction:
Myocardial infarction (MI) is the primary manifestation of cardiovascular events. Synthetic cardiac stromal cells (synCSCs) were shown to promote cardiac repair after MI. Minimally invasive delivery of synCSCs embedded in hyaluronic acid (HA) hydrogel via intrapericardial cavity (iPC) injections in a porcine model may provide a unique dataset for cardiac regeneration therapeutics.

Hypothesis:
Minimally invasive delivery of synCSCs via iPC injection will improve pig cardiac function and cardiomyocyte (CM) proliferation.

Methods:
A pig MI model was created using coronary balloon occlusion, and Yorkshire male pigs underwent video-assisted thoracoscopic surgery for iPC injections. Cardiac function studies were conducted using MRI to measure left ventricle ejection fraction (LVEF) and the infarct area. Histology and immunohistochemistry (IHC) analyses were performed to investigate CM proliferation. Single nucleus RNA-sequencing (snRNA-sq) analysis was performed to identify key gene features and phenotype changes that may be affected by the synCSC treatment.

Results:
The iPC injection of synCSCs embedded in HA hydrogel improves cardiac function, enhances cardiomyocyte proliferation, and induces phenotype alteration in the pig MI model. MRI analysis depicts significantly attenuated infarct size and improved LVEF at Day 28 in the synCSC group. Histology shows reduced fibrotic percentage and improved infarct wall thickness. IHC analysis shows a significant increase in cardiomyocyte proliferation. SnRNA-seq elucidates immature cardiomyocytes with higher proliferation gene features.

Conclusion:
The results show significant improvements in pig cardiac function and CM proliferation. Interestingly, immature cardiomyocytes of a different phenotype emerged in the therapeutic group. These findings provide an unprecedented dataset to facilitate the clinical translation of cardiac tissue regeneration therapeutics.
Abstract 17407: A Small-molecule Screening Strategy to Promote Cardiomyocyte Proliferation That Protects the Heart From Ischemic Injury
Authors: Zhang Zhenhe , Freeman Miles , El-nachef Danny O , Lu Yan , Xu Haodong , MacLellan W Robb
Published: December 2023

Restoring the ability of adult cardiac myocytes (ACMs) to proliferate and promote heart regeneration have been proposed as a promising therapeutic strategy. We have demonstrated that selective depletion of H3K9me3 by lysine demethylase 4D (KDM4D) overexpression increases ACM cell cycle activity, but proliferation was limited. To improve this, we performed a small-molecule screening in combination with KDM4D on neonatal rat cardiomyocytes (NRVMs), using a library of kinase inhibitors targeting different signaling pathways. Our study revealed that compounds targeting the PI3K and JAK signaling pathways significantly potentiated the effects of KDM4D and promote NRVM proliferation in vitro. Specifically, a JAK inhibitor (JAKi2) in combination with Ad-KDM4D treatment resulted in approximately 100%, 34%, and 62% increase in EdU+, phospho-H3+, and total cell number compared to control, respectively. To validate these findings in vivo, we tested JAKi2 in an inducible KDM4D transgenic mouse model (iKDM4D). The animals underwent ischemia/reperfusion (I/R) to induce infarction, and JAKi2 was administrated orally for up to 8 weeks. We found both early and late effects. 48 hours after I/R, the infarct size in iKDM4D+JAKi2 hearts was approximately 4-fold smaller than that in vehicle-treated or JAKi2 alone groups, and the combination increased EdU+, Ki67+, and phospho-H3+ CM number separately by 3.2-fold, 2.9-fold, and 6.5-fold. At 2 weeks post-I/R, the scar size was smaller in iKDM4D+JAKi2 hearts compared to vehicle-treated mice (9.0% vs 1.8%,
P
<0.05), and the combination resulted in a 3-fold, 5.5-fold, and 8.5-fold increases in EdU+, Ki67+, and phospho-H3+ CMs, respectively. Moreover, the iKDM4D+JAKi2 hearts demonstrated progressive improvement in left ventricular ejection fraction (26.8%, 27.3%, and 25.5%) and fraction shorten (37.9%, 38.1%, and 35.0%) at 2 weeks, 4 weeks, and 8 weeks post-I/R. The increased estimated ACM number and mononucleated CMs at 8 weeks post-I/R support that CM division was increased in the iKDM4D+JAKi2 hearts. These findings suggest that a combination therapy involving JAKi2, along with KDM4D, promotes robust CM proliferation and protects the heart after ischemic injury.
Abstract 17430: Targeting DNA Hypermethylation With Hypomethylating Drugs: Implications for Pulmonary Arterial Hypertension
Authors: Reem EL-Kabbout , ABI SLEIMAN ANTONELLA , SALEM MABROUKA , Breuils Bonnet Sandra , Bourgeois Alice , Martineau Sandra , Lemay Sarah-Eve , Romanet Charlotte , Theberge Charlie , Boucherat Olivier , Provencher Steeve , Bonnet Sebastien , Potus Francois
Published: December 2023

Introduction:
Pulmonary arterial hypertension (PAH) is a lethal vasculopathy characterized by sustained vasoconstriction and remodeling of pulmonary arteries. Excessive proliferation and reduced apoptosis of pulmonary artery smooth muscle cells (PASMCs) contribute to pulmonary artery remodeling, with limited efficacy of current pharmacotherapies. Increased DNA methylation (DNAm) has been implicated in pro-proliferative phenotypes and disease progression in cancer and cardiovascular diseases.

Hypothesis:
We hypothesized that increased DNAm contributes to the pro-survival phenotype of PAH-PASMCs and that targeting DNA methylation could improve PAH development.

Methods and Results:
Our study revealed a global increase of DNAm in remodeled pulmonary arteries of human PAH patients and three preclinical models (namely monocrotaline, sugen hypoxia, Fawn hooded rats, p<0.05, immunofluorescence [IF] 5mc/SMA). In vitro, PAH-PASMCs exhibited elevated DNAm levels (IF 5mc, p<0.05), increased expression of DNA methyltransferases (DNMT1, DNMT3a; Western blot [WB], p<0.05), and decreased expression of DNA demethylase (TET2; WB, p<0.05). Consequently, hypomethylating drug Zebularine demonstrated dose-dependent reductions in PAH-PASMC proliferation (WB for surviving, plk1, MCM2; IF ki67, p<0.05) and increased apoptosis (WB for Bax/BCL2; IF annexinV, p<0.05,). Transcriptomic and gene ontology analyses indicated that these effects likely involve the downregulation of biological processes related to the cell cycle and mitosis. In vivo treatment with Zebularine (10 mg/kg, 2 weeks, intraperitoneal injection) improved PAH hemodynamics (e.g., decreased RVSP, vascular resistances, p<0.05), decreased PASMC methylation (IF 5mc/SMA, p<0.05) and proliferation (IF ki67/SMA, p<0.05), and mitigated adverse pulmonary vascular remodeling in two rodent models of the disease (monocrotaline and sugen hypoxia). Statistics: unpaired t test (2 groups), ANOVA (> 2 groups).

Conclusions:
Our findings demonstrate an association between increased DNA methylation and PAH development. Targeting DNAm represents a potential therapeutic avenue for PAH, as evidenced by the beneficial effects of Zebularine in improving PAH-related phenotypes.
Abstract 17432: Utilization of Heart Failure Therapies: Assessing Trends and Adoption of Updated Guideline Directed Medical Therapy Following the 2022 Heart Failure Guideline Release
Authors: Narendrula Aparna , Issa Rochell , Tang Wai Hong W , Kaelber David , Kwon Deborah H
Published: December 2023

Introduction:
The adoption rate of new guideline-directed medical therapy (GDMT) for heart failure with reduced ejection fraction (HFrEF) is unclear. Thus, we assessed temporal trends in GDMT prescription following the release of the 2022 ACC/AHA heart failure guidelines.

Methods:
Using the TriNetX database, we identified HFrEF patients with an EF = 40%. Seven 2-month time windows between April 1, 2022 and May 31, 2023 were analyzed. Treatment categories included sacubitril (proxy variable for angiotensin receptor/neprilysin inhibitor), angiotensin-converting enzyme inhibitors (ACEi), beta blockers, mineralocorticoid-receptor antagonists, sodium glucose transport 2 inhibitors (SGLT2i), isosorbide dinitrate, ivabradine, hydralazine, and ICD/CRT. Incidence rate and prevalence of GDMT prescription were assessed over 14 months post-guideline publication.

Results:
Analysis included 167,740 HFrEF patients. Sacubitril prevalence doubled between 2022 (18.326%) and 2023 (36.779%), with a higher rate of increase after January 2023. ARB prescription prevalence increased from 39.031% to 58.696%, with notable incidence growth after January 2023. Prevalence of SGLT2i prescription increased from 14.794% in 2022 to 34.14% in 2023. Incidence rates for other therapies also showed upward trends, resulting in increased overall therapy prevalence. Slightly lower 1-month hospitalization (46.378% vs 46.654%) and mortality (7.327% vs 7.549%) were observed in the 14 months after guideline publication compared to the 14 months prior.

Conclusions:
Improved adherence to GDMT guidelines has occurred since the release of the 2022 guidelines. Notably, utilization of ARNIs and SGLT2 inhibitors significantly increased. However, prescription rates for these novel therapies were below 50%, highlighting the need to expand access to a larger proportion of HFrEF patients.
Abstract 17447: Effects of Inflammatory Biomarkers on Epigenetic Age Acceleration in Adult Congenital Heart Disease
Authors: Jain Parag N , Zhuang Beryl , Whitehead Joanne , Kobor Michael S , Checchia Paul
Published: December 2023

Introduction:
DNA methylation (DNAm) changes reflect alterations in the immune response to cardiac surgery in older adults. However, the role of inflammation on epigenetic age acceleration (EAA) in adults with congenital heart disease (ACHD) who underwent palliative cardiac surgery during childhood is unknown.

Hypothesis:
ACHD patients with Fontan(F) procedures would have advanced EAA due to higher DNAm predicted IL-6 and CRP levels compared to healthy adults or ACHD patients who underwent single surgery as an infant, likely capturing chronic inflammation associated with the abnormal pathophysiologic state.

Methods:
A case-control study in young adults (aged 20-30 years) with Fontan circulation or single surgery (SS) as an infant at a tertiary ACHD hospital. DNAm were measured by the EPIC Array. DNAm predicted IL-6 and CRP level differences were tested by robust linear model (rlm) adjusted for age, sex, cell types, and self-reported ethnicity. EAAs were calculated by extracting residuals by regressing epigenetic ages on chronological age in linear regression models. EAA differences were tested by rlm adjusted for the same covariates. Contribution analysis was performed to determine contribution of IL-6 and CRP to EAA.

Results:
Thirteen Fontan patients (6 female: 7 male, median age: 23) and 5 SS patients (3 female: 2 male, median age: 23) were compared with 20 age-matched controls (15 female: 5 male, median age: 27). Each subgroup had a predominant white race and non-Hispanic ethnicity. The F group has a statistically higher predicted IL-6 and CRP level (p<0.001). Also, the F group had significantly higher EAA for mortality predictor Grimage (p<0.001) and PhenoAge (p<0.001).

Conclusions:
Patients who underwent Fontan procedure experience advanced EAA contributed by inflammatory biomarkers at a young age. Future studies evaluating the key predictors that drive EAA difference is needed to understand the impact of chronic alteration of physiology.
Abstract 17455: Heart in Crisis: Graves’ Thyrotoxicosis-Induced Cardiomyopathy
Authors: Nnadi Ekendilichukwu , Khatun Nazima , Graham-Hill Suzette
Published: December 2023

Background:
We present a case of a young healthy male who presented with signs and symptoms of congestive heart failure and was subsequently diagnosed with dilated cardiomyopathy secondary to an unknown history of Graves’ disease.

Case Presentation:
A 40-year-old male with no medical history presented to the hospital with scrotal and bilateral lower leg edema for 4 days with associated shortness of breath. Physical examination was significant for an irregularly irregular heart rhythm. Electrocardiogram showed atrial fibrillation with a rapid ventricular response (Image B). Initial laboratory findings were elevated NT-proBNP of 1,240 pg/mL (<125 pg/mL). Chest x-ray revealed significant cardiomegaly (Image A). Echocardiogram demonstrated an ejection fraction of 20% with a severely dilated bilateral atrium, left ventricle with severe diffuse hypokinesis of the left ventricle, and severe mitral regurgitation (Images C and D). Endocrine was consulted for abnormal thyroid function tests with TSH of <0.010 mU/L (0.27-4.2 mU/L), free T4 of 6.06 ng/dL (.93-1.70 ng/dL), T3 of 258 ng/dL (80-200 ng/dL), thyroid-stimulating immunoglobulin of 9.51 IU/L (0.00-.55 IU/L) and TSH receptor antibody 14.00 IU/L (0.00-1.75 IU/L). The patient was started on methimazole and metoprolol with close follow-up with cardiology and endocrinology.

Discussion:
Severe Cardiomyopathy in adult patients with hyperthyroidism is rare occurring in approximately 6% of patients with less than 1% developing dilated cardiomyopathy with impaired left ventricular systolic function. Although the mechanism of dilated cardiomyopathy is still being researched it has been suggested that prolonged uncontrolled hyperthyroidism and autoimmunity as the potential causes. Further studies are needed to develop optimal management studies as it has been shown that the management of thyrotoxicosis can reverse cardiovascular manifestations and prevent irreversible cardiomyopathy.
Abstract 17456: Inositol 1,4,5-Trisphosphate Receptors (ITP3Rs) and Activation of Cardiac Fibroblasts in Ischemia/Reperfusion Injury
Authors: Kansakar Urna , Jankauskas Stanislovas S , Gambardella Jessica , Varzideh Fahimeh , Wang Xujun , Santulli Gaetano
Published: December 2023

Introduction:
Inositol 1,4,5-trisphosphate receptors (ITP3Rs) are Ca
2+
release channels on the endoplasmic reticulum (ER). The role of ITP3Rs in cardiomyocytes has been previously investigated for hypertrophy and arrhythmias, however, the exact function in the activation of cardiac fibroblasts (FBs) is yet to be determined. The main goal of this project is to investigate the mechanisms linking FB ITP3Rs to post-ischemia/reperfusion (I/R) cardiac fibrosis.

Hypothesis:
We hypothesize that ITP3Rs activate FB via a direct transcriptional regulation of αSMA and other genes involved in myoFB activation. Indeed, myoFB differentiation and persistence is regulated by a balance between pro-and anti-apoptotic signaling pathways.

Methods:
We generated myoFB-specific ITP3Rs KO mice (ITP3R
KO
) and isolated FBs as well as cardiomyocytes via collagenase digestion and performed immunoprecipitation (IP) assays showing that ITP3Rs bind p53 upregulated modulator of apoptosis (PUMA). Cytosolic levels of Cytochrome C (Cyt C) were assessed in myoFB isolated from areas remote from injury and scar areas 7 d after I/R. After having immunoprecipitated for ITP3R1 we blotted the isolated FBs for PUMA and, vice versa. PUMA levels were measured in cytosol, ER, and mitochondria of FBs isolated from regions remote from injury and scar areas 7 d post I/R.

Results:
Our data show reduced levels of cytosolic Cyt C following I/R, which was prevented by IP3Rs ablation, providing an explanation for the persistence of myoFBs in remote areas. We found that the mitochondrial expression of PUMA was significantly decreased - while ER levels were markedly increased - in myoFBs isolated from areas remote from I/R injury, indicating a sequestration of PUMA by ITP3Rs; this phenotype was rescued by ITP3Rs ablation. Instead, in myoFBs isolated from the scar areas, mitochondrial PUMA levels were increased both in ITP3R
fl/fl
and ITP3R
KO
mice, and no sequestration was observed, consistent with the absence of ITP3R upregulation.

Conclusions:
Using a specific Cre/lox KO model, we provide the first assessment of functional contribution of ITP3R to post-I/R activation of cardiac FBs and understanding the molecular mechanisms underlying excessive reactive fibrosis in the heart.
Abstract 17458: Diet Quality Mediates the Relationship Between Chronic Stress and Inflammation in Patients With Metabolic Syndrome
Authors: Kang JungHee , Moser Debra K , Lennie Terry , Chung Misook L , Thomas Travis , Biddle Martha J
Published: December 2023

Background:
Metabolic syndrome is associated with a two-fold increase in cardiovascular disease (CVD) outcomes. Chronic stress is related to poor diet and development of metabolic syndrome. Inflammation plays an essential role in metabolic syndrome and can be moderated by diet. Hypothesis: Diet quality mediates the relationship between chronic stress and inflammation in patients with metabolic syndrome.

Methods:
Participants with metabolic syndrome (n=73, 62±12 years old, 71% female) completed questionnaires on chronic stress (Perceived Stress Scale [PSS-10]) and diet quality (Healthy Eating Index [HEI-2015]). The PSS-10 was dichotomized (highest quartile -Higher stress group- vs. lower quartiles -Lower stress group-). The HEI-2015 is comprised of 13 dietary components. Higher HEI-2015 scores indicate better diet quality. Inflammation was assessed by plasma high-sensitivity C-Reactive protein (hs-CRP). We used the PROCESS macro to test mediating roles of HEI-2015 between chronic stress and hs-CRP (log-transformed).

Results:
Higher stress group had worse mean HEI-2015 scores (64 ± 10 vs. 57 ± 13, P = .02). Among the 13 dietary components, the greatest differences between higher and lower stress groups were fruits and vegetable component scores (P < .05). As shown in Figure, diet quality mediated the relationship between chronic stress and inflammation (indirect effect = a*b = .211, 95% Confidence Interval [CI] = .006 to .496). Higher chronic stress group was associated with lower diet quality (a = - 7.152, 95% CI = - 13.168 to - 1.137), and, in turn, increased inflammation (b = - .030, 95% CI = - .052 to - .007).

Conclusions:
Our findings show the important role of diet quality in the relationship of chronic stress with inflammation in patients with metabolic syndrome. Increased intake of fruits and vegetables may be one of the most important recommendations for lowering inflammation and reducing CVD risks in highly stressed patients with metabolic syndrome.