bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 461: Alcohol Modulates Chemokine- And Hypoxia-induced Endothelial-to-mesenchymal Transition In Vitro And Following Ligation Injury In Vivo
Authors: Rajendran Naresh K , Liu Weimin , Cahill Paul A , Redmond Eileen M
Published: October 2023

Endothelial-to-mesenchymal transition (EndMT) plays a role in arteriosclerotic cardiovascular disease (CVD). Low-to-moderate alcohol consumption (i.e., 1-3 drinks/d range) protects against endothelial dysfunction and arteriosclerosis, in part by stimulating Notch, but whether it does so by influencing EndMT is unknown. Our aim was to address this question. Human coronary artery endothelial cells (HCAEC) (p5-p14) were treated (7 d) with transforming growth factor β (TGFβ, 10 ng/ml) or exposed to hypoxia (5% O
2
), in the absence or presence of ‘moderate’ level EtOH (25 mM), or the Notch ligand DLL4 +/- the Notch inhibitor DAPT. EndMT was assessed by determining endothelial marker CD31 and smooth muscle cell marker αSMA expression by immunohistochemistry and qRT-PCR, as well as by cell morphology and extracellular matrix protein Fibronectin production. Both TGFβ and hypoxia induced EndMT of HCAEC as determined by simultaneously decreased CD31 and increased αSMA expression, together with a change in morphology from cobblestone (typical of endothelial cells) to spindle-shaped (typical of mesenchymal cells), and increased fibronectin expression. EtOH inhibited EndMT caused by both TGFβ and hypoxia as indicated by maintenance of CD31 expression and cobblestone morphology, and attenuated αSMA and fibronectin expression in the EtOH treated group vs controls. Similar to EtOH, treatment with DLL4 inhibited TGFβ-induced myogenic αSMA and fibronectin mRNA expression in HCAEC, effects blocked by DAPT. Following carotid ligation in C57Bl/6 mice, ~25% of neointimal and medial cells in the remodeled vessel co-expressed αSMA and CD31 (indicative of myo-endothelial cells), suggesting the involvement of EndMT. In the ‘daily moderate’ alcohol group (2 drinks per day equivalent; peak BAC=15 mM) carotid neointimal hyperplasia was reduced compared to controls concomitant with fewer (<10%) αSMA
+
/CD31
+
myo-endothelial cells suggesting repression of EndMT in that cohort. In conclusion, these data illuminate an inhibitory effect of alcohol on EndMT, potentially mediated via Notch. This effect on endothelial transdifferentiation may underlie, in part, the protective effect of moderate alcohol consumption on CVD.
Abstract 466: CD36 Mediates Mitochondrial Reactive Oxygen Species Production Through PKM2 In Macrophages
Authors: Zhang Jue , Chang Jackie , Beg Mirza Ahmar , Chen Vaya , Chen Yiliang
Published: October 2023

Introduction:
Excessive mitochondria-derived reactive oxygen species (mtROS) are associated with foam cell formation and atherosclerosis progression in both animal models and human patients. We previously showed that oxLDL/CD36 signaling stimulated mtROS production and facilitated diet-induced atherosclerosis in mice. However, underlying mechanisms by which oxLDL/CD36 pathway mediates mtROS production during atherosclerosis remain elusive. Pyruvate kinase M2 (PKM2) is a glycolytic enzyme recently discovered to facilitate foam cell and atherosclerosis development. We hypothesize that oxLDL/CD36 signaling mediates mtROS production by stimulating PKM2 mitochondrial translocation.

Methods and Results:
We separated mitochondria and cytosol fractions in murine peritoneal macrophages. OxLDL treatment upregulated PKM2 protein level in mitochondria fractions in a time-dependent manner (peak at 3h, ~2.5 fold), but not in cytosol. Confocal imaging further confirmed a translocation of PKM2 to mitochondria induced by oxLDL. This phenomenon was not observed in CD36-deficient macrophages. To investigate the mechanism, we immunoprecipitated PKM2 followed by mass spectrometry analysis of proteins associated with PKM2. GRP75, a known chaperone protein that imports cytosol proteins to the mitochondria was identified. Co-IP assay confirmed the interaction between GRP75 and PKM2, which was augmented by oxLDL (~3 fold). Moreover, UQCRC1, a subunit of mitochondrial electron transport chain (ETC) complex III, a major site of mtROS production, was also identified from mass spectrometry. Increased interaction between PKM2 and UQCRC1 induced by oxLDL (~3 fold) was further validated by coIP and in situ proximity ligation assay, which was dependent on CD36.In addition, PKM2 inhibitor Shikonin and PKM2 siRNA both inhibited the oxLDL-induced mtROS generation (by 50% and 100% respectively) in murine macrophages and human monocytes-derived macrophages.

Conclusions:
OxLDL/CD36 axis promotes PKM2 translocation to mitochondrial which facilitates mtROS production in macrophages. It highlights the novel role of PKM2 in mtROS production during atherosclerosis and implicates GRP75-PKM2-UQCRC1 axis as a potential therapeutic target.
Abstract 483: Monocyte-derived Dll4 Is A Novel Contributor To Persistent Systemic Inflammation In HIV Patients
Authors: Wang Shumin , Singh Meera , Yang Hongmei , Morrell Craig , Awad Mohamad Laith , Xu Jasmine Jiayuan , Nguyen Tiffany , Ture Sara , Tyrell Alicia , Maggirwar Sanjay B , Schifitto Giovanni , Pang Jinjiang
Published: October 2023

Background:
In HIV patients on combination antiretroviral therapy (cART), persistent systemic inflammation is a driving force for the progression of comorbidities, such as cardiovascular diseases. Monocyte and macrophage-related inflammation rather than T cell activation is a major cause of chronic inflammation. However, the underlying mechanism of how monocytes cause persistent inflammation is multifaceted.

Methods and Results:
In vitro, we demonstrated that lipopolysaccharides (LPS) or tumor necrosis factor alpha (TNFα), induced a robust increase of Delta-like ligand 4 (Dll4) mRNA and protein expression in human monocytes and Dll4 secretion (extracellular Dll4, exDll4) from monocytes. Enhanced Dll4 expression in monocytes triggered Notch1 activation to promote pro-inflammatory factors expression. Dll4 silencing and inhibition of Nocth1 activation diminished the LPS or TNFα -induced inflammation. exDll4 releases in response to cytokines occurred in monocytes but not endothelial cells or T cells. In clinical specimens, we found that people living with HIV (PLWH), both male and female, on cART showed a significant increase in membrane-bound Dll4 (mDll4) expression, activation of Dll4-Notch1 signaling, and inflammation in monocytes. Surprisingly, plasma exDll4 was remarkably elevated in HIV male patients but not female patients, and its levels paralleled with monocytes mDll4 in HIV male patients. In addition, circulating exDll4 was positively associated with pro-inflammatory monocytes and negatively associated with classic monocytes in HIV male patients.

Conclusion:
Pro-inflammatory stimuli increase Dll4 expression and Dll4-Notch1 signaling activation in monocytes and enhance monocyte inflammation, contributing to persistent systemic inflammation in PLWH. Plasma exDll4 is mainly released from monocytes and could act as a potential biomarker of HIV-related cardiovascular diseases caused by monocyte-mediated inflammation in HIV male patients. mDll4 in monocytes could be a potential biomarker of inflammation for both genders of HIV patients.
Abstract 490: High-dimensional Proteogenomics Of Human Carotid Atherosclerosis Reveals Significant Diversity Of Smooth Muscle Cells Within Plaques
Authors: Bashore Alexander , Yan Hanying , Xue Chenyi , Zhu Lucie , Mawson Thomas , Li Mingyao , Reilly Muredach P
Published: October 2023

Atherosclerotic lesions are cellularly heterogeneous tissue comprised of diverse cell types including smooth muscle cells (SMCs), endothelial cells, and immune cells. The development of single cell technologies has provided the granular resolution required to identify new cell types present in plaques, aiding in our understanding of the pathophysiology of the disease. Transdifferentiation of SMCs during atherosclerosis progression to a synthetic phenotype has a major influence on disease severity and development. Therefore, to deeply characterize and immunophenotype SMCs in atherosclerotic plaques we performed cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq) on six patients and scRNA-sequencing on fifteen patients undergoing carotid endarterectomy. Our initial analysis identified 25 unique cell populations, which consisted of 4 SMC populations which comprised about 14% of all cells in the dataset. Three of the SMC populations appeared to have a contractile phenotype, with high expression of SMC-specific genes like ACTA2, MYH11, and CNN1. The fourth SMC cluster had a modulated phenotype with downregulation of SMC genes and an up regulation of fibroblast genes such as COL1A2 and LUM. We also identified novel and uncharacterized SMC-specific cell surface proteins such as CD29, CD142, and EGR. The modulated SMC cluster specifically expressed CD90, giving us the unique ability to differentiate these similar yet distinct cell types. We then performed a subclustering analysis on SMC and fibroblast populations, identifying 8 SMC subpopulations. This was followed by Canonical Pathway analysis with Ingenuity Pathway Analysis (IPA) using the most highly expressed genes in each cluster to identify enriched pathways. This revealed a diverse array of functional differences between SMC populations. Our data support the idea that SMCs have a vast array of phenotypic states and functions. Future work will uncover the relevance of these newly identified cell types in the development of atherosclerosis and clinical events.
Abstract 511: Novel Thrombolytic Agent Showing Unique Lysis Of Platelet-Rich Thrombi
Authors: Bakshi Saagar C , Rivera-Crespo Gian , Ku David N
Published: October 2023

Background:
Acute arterial thrombosis, formed primarily by platelets and vWF under high shear, causes significant morbidity and mortality by occluding end-organ blood flow. These platelet thrombi are often resistant to thrombolysis by tPA and other therapeutics due to minimal fibrin. We have recently discovered a new compound N,N'-diacetyl-L-cystine (DiNAC) that effectively lyses platelet-rich blood clots.

Objective:
The purpose of this study is to evaluate the efficacy of DiNAC as a lytic agent against platelet-rich occlusive thrombi made from human whole blood.

Methods:
Occlusive thrombi were made from heparinized human whole blood, collected from healthy volunteers, in an in-vitro flow loop. Blood was perfused using a syringe pump through a glass stenosis coated with fibrillar collagen and observed through a microscope with continuous recording. Pressure was measured continuously upstream and downstream of the stenosis. After thrombosis occurred, a 10mM DiNAC solution was perfused. Lysis was measured using image capture and pressure differential recording. Thrombolytic response of DiNAC was compared with saline control and analyzed for significance.

Results:
Perfusion with 10 mM DiNAC created effective thrombolysis of the clot with visual flow restoration. The pre-stenosis backpressure returned to pre-occlusion levels and thrombus surface area was reduced by 70% (n=10). In contrast, saline control had no appreciable effect on surface area or pressure (n=10, p<0.01).

Conclusion:
DiNAC is a novel compound with the ability to lyse platelet-rich arterial thrombi, repeatably restoring flow after occlusive platelet thrombus formation in-vitro with human blood. These promising results pave the way for clinical studies evaluating the effectiveness and safety of DiNAC for arterial thrombolysis.
Abstract 518: Microtubule-stabilizing Drug Epothilone D Protects Mice From Angiotensin II-induced Abdominal Aortic Aneurysmal Rupture
Authors: Frony Ana Clara S , Javidan Aida , Jiang Weihua , Yang Lihua , Subramanian Venkateswaran
Published: October 2023

Background and Objective:
Abdominal aortic aneurysms (AAAs) are permanent dilations of the aorta with 80% mortality after rupture. AAA is associated with the destruction of aortic vascular cellular components including cellular cytoskeleton. Microtubules are heterodimers of globular proteins- α- and β- tubulins, which form a major part of the cellular cytoskeleton and provide stability to cell structure and shape. Microtubule stabilization is emerging as an effective approach to improve cell cytoskeletal stability under various disease conditions. Currently, the functional contribution of cellular microtubule stabilization in AAA development is not known. The purpose of this study is to examine the effect of an FDA-approved microtubule-stabilizing drug, Epothilone D (EpoD) on Angiotensin II (AngII)-induced AAA formation in mice.

Methods and Results:
To examine microtubule protein distribution in AAAs, human and AngII-induced mouse AAAs and non-aneurysmal abdominal aorta (NAA) were immunostained using antibodies against microtubule protein, α- tubulin. Immunostaining analyses revealed that both human and mouse AAAs are associated with decreased α- tubulin protein compared to NAAs. To examine the effect of the microtubule-stabilizing drug, EpoD on AngII-induced AAA formation, male LDL receptor -/- mice (16 weeks old; n=10 per group) were fed a fat-enriched diet (21% fat; 0.15% cholesterol) for 5 weeks. The vehicle or microtubule-stabilizing drug, EpoD (3 or 10 mg/kg, i.p.) was administered twice a week for 5 weeks. After 1 week of diet feeding and EpoD dosing, mice were infused with AngII (1,000 ng/kg/min) by osmotic minipumps for 4 weeks. EpoD administration had no significant effect on AngII-induced AAA expansion as measured by ex vivo diameter (Vehicle: 1.50 ± 0.30 mm vs EpoD (3 mg/kg): 1.90 ± 0.70 mm; EpoD (10 mg/kg): 1.40 ± 0.20 mm;
P
= 0.58). EpoD administration significantly suppressed AngII-induced AAA rupture in a dose-dependent manner compared to the vehicle group (AAA Rupture: Vehicle: 70% versus EpoD (3mg/kg): 20%; EpoD (10mg/kg): 0%, P<0.05, respectively).

Conclusion:
These findings demonstrate that microtubule stabilization by EpoD significantly suppresses AngII-induced AAA rupture without influencing AAA formation in mice.
Abstract 522: Computational Fluid Dynamics Analyses Of Geometric Incompatibility And Seal Zone Stability In Endovascular Aneurysm Repair
Authors: Li Willa , Donik Žiga , Polcari Kayla , Sankary Seth , Dhara Sanjeev , Cao Kathleen , Nguyen Nhung , Kramberger Janez , Pocivavsek Luka
Published: October 2023

Introduction:
Long-term durability of endovascular aneurysm repair (EVAR) is often compromised due to inadequate sealing of the endograft to the aorta. We hypothesize that geometric mismatch between the aorta and endograft can lead to the development of bird-beak regions, type Ia endoleaks, and endograft migration. Our novel computational model shows how geometric incompatibility at the seal zone contributes to endoleak formation and propagation.

Methods:
Using finite-element modeling, we simulated endograft crimping and deployment in pressurized aortic models with different degrees of curvature (0°, 30°, 60°) and oversizing (0%, 20%, 25%). We then performed computational fluid dynamics (CFD) modeling with a detailed pressure analysis of various regions along the length of each model.

Results:
Across our models, pressure gradients developed between the bulk flow and endoleak regions. For all degrees of curvature, the average total pressure in the endoleak region was higher than that of the bulk flow in the 20% and 25% oversized models. While oversizing decreased the aorta-endograft geometric mismatch in the 60° model and mitigated the volume of endoleak, too much oversizing in the 0° models worsened endoleak.

Conclusions:
We present one of the first computational models to study the sensitivity of seal zone mechanics to the degree of aorta-endograft mismatch. Our finding of pressure gradients that exist between the endoleak and bulk flow may represent regions of high mechanical instability that may further propagate the endoleak. Our results highlight the importance of shape and oversizing considerations when selecting the appropriate endovascular therapy for EVAR patients.

Figure 1:
CFD simulations of aorta-endograft models with different degrees of curvature and oversizing show endoleak formation as a function of geometric incompatibility.
Abstract 528: Endothelial Estrogen Receptor Alpha Deletion Promotes Abdominal Aortic Aneurysm In Male Mice
Authors: Sharma Neekun , Ferreira-Santos Larissa , Morales-Quinones Mariana , Power Gavin , Padilla Jaume , Martinez-Lemus Luis A , Manrique-Acevedo Camila
Published: October 2023

Introduction:
Although men have a greater incidence of abdominal aortic aneurysm (AAA) compared with women, the role of sex-hormones in mediating these differences is not well understood. Given the known effect of estrogen receptor alpha (ERα) signaling in maintaining vascular wall homeostasis, the present study examines its role in the pathogenesis of AAA. Specifically, we scrutinize whether endothelial cell (EC) ERα protects against AAA via increased lysyl oxidase (LOX) activation and regulation of vascular smooth muscle cell (VSMC) phenotype.

Methods:
AAA was induced in male and female ECERα knockout (ECERαKO) mice and their littermates (n=6-11) by administering β-Aminopropionitrile (BAPN) via drinking water (1 mg/ml; 0.15 g/kg/d) from 3 days prior to angiotensin II (Ang II; 1 μg/kg/day) infusion for 2 weeks. The development of AAA was assessed by ultrasound measurement of aortic luminal dilation and histology. Relevant molecular mechanisms were examined in abdominal aorta and in human aortic endothelial cells (HAECs).

Results:
BAPN Ang II resulted in an increased incidence of AAA in male ECERαKO mice (72%), whereas female ECERαKO mice did not develop aneurysms. No difference in AAA incidence was observed between male and female littermate control mice (12.5%). Elastin fragmentation was significantly higher only in male ECERαKO mice compared to littermates, while female ECERαKO and their littermates had comparable elastin fragmentation. Ang II receptor type 1a mRNA expression was higher in male ECERαKO, whereas female ECERαKO mice had higher Ang II receptor type 1b mRNA expression. Gene expression of smooth muscle alpha-actin and smooth muscle 22 (contractile VSMC markers) was significantly higher in female aortas compared to males irrespective of genotype, whereas, osteopontin, synthetic VSMC marker was only upregulated in male ECERαKO. HAECs treated with estradiol (10 nM, 24 h) significantly increased LOX activity.

Conclusions:
Our findings identify a critical role of endothelial ERα in protection against AAA in male mice likely through increased LOX activity and maintenance of VSMC phenotype. Further studies are needed to delineate the crosstalk between endothelial ERα and VSMCs, and their impact in the pathogenesis of AAA.
Abstract 529: Management Of Acute Aortic Syndrome With Evolving Individualized Precision Medicine Solutions: Lesson Learned Over Two Decades And Literature Review
Authors: Sultan Sherif , Acharya Yogesh , Hynes Niamh
Published: October 2023

Background:
Thoracoabdominal acute aortic syndrome is associated with high morbidity and mortality. We aim to scrutinize our evolving strategies for acute aortic syndromes (AAS) management using minimally invasive and adaptive surgical techniques.

Methods:
This is a longitudinal observational study at our tertiary vascular centre from 2002 to 2021. Amongst 96 with symptomatic aortic thoracic pathologies, 71 had AAS. Our primary endpoint was combined aneurysm and cardiovascular-related mortality.

Results:
There were 43 males and 28 females (5 Traumatic Aortic Transection (TAT), 8 Intramural Hematoma (IMH), 27 Symptomatic Aortic Dissection (SAD) and 31 Thoracic Aortic Aneurysm (TAA)) with a mean age of 69. All AAH received optimal medical therapy (OMT) and TAT underwent emergency thoracic endovascular aortic repair (TEVAR). Fifty-eight patients had aortic dissection, of which 31 developed TAA. These 58 received OMT initially and interval surgical intervention with TEVAR or sTaged hybrId sinGle lumEn Reconstruction (TIGER). To increase our landing area, we performed left subclavian chimney graft with TEVAR in 12 patients. Average follow-up was 78.2 months, and 15.5% (11/71) patients had combined aneurysm and cardiovascular-related mortality. None had stroke or bowel ischaemia. 26% (12/46) developed endoleaks and 15% (7/46) required re-intervention (type II & III). Four patients had paraplegia (5.7%, 4/71) and succumbed to death from renal failure. Eight IMH patients on OMT died within 30 days.

Conclusion:
Acute aortic hematoma necessitates close monitoring and early intervention. TIGER technique with interval TEVAR has salvaged complex situations in young patients. Our experience shows that minimally invasive techniques could be a viable option for AAS.
Abstract 544: Evaluating The Diagnostic Ability Of Six Different Artificial Neural Networks From The Subcellular Microenvironment To The Clinical Manifestation
Authors: Miserlis Dimitrios , Munian Yuvaraj , Fletcher Emma , Crapps Josh , Teixeira Pedro , Ferrer Lucas , DuBose Joseph , Bohannon William T , Monteleone Peter , Alamaniotis Miltiadis , Koutakis Panagiotis
Published: October 2023

Peripheral arterial disease (PAD) is affecting a large number of patients in the USA and worldwide. The natural history of the disease leads to detrimental clinical implications including walking disability, pain and eventually limb loss. The clinical management of the disease is largely based on clinical criteria (e.g. pain, tissue loss). We have prepared muscle biopsy specimens from patients with PAD versus control subjects and utilizing electron-microscopy we captured in the subcellular level the mitochondrial architecture changes. Using the acquired data as input we tested the ability of six structurally different artificial neural networks (ANNs) to identify PAD patients. For the study we acquired human tissue biopsies from the gastrocnemius muscle. The specimens were processed and cut as ultrathin sections (70 nm) for analysis using a JEM1010 transmission electron microscope. The images were used to generate an image preprocessing database of 992 images and subsequently a custom python-based code was developed with Keras - TensorFlow platforms in order to perform the ANN analysis. We implementing six different deep artificial neural network architectures namely, VGG-19 , ResNet50 , Densenet201 , InceptionV3 , InceptionsResnetV2 and EfficientNetB7.The diagnostic accuracy was found to be respectively: VGG-19 0.81%, ResNet50 0.75%, Densenet201 0.81%, InceptionV3 0.79%, InceptionsResnetV2 0.78% and EfficientNetB7 0.87%.This study presents data for the ability of simple and more advanced ANNs to perform diagnostic predictions based on electron microscopy images of intracellular organelles. The ability to take advantage of applied artificial intelligence technologies and serve this information for clinical decision making could be a pathway for improved patient care. The presented work established insight in some of the currently available deep artificial neural networks, applied in a daily clinical problem and their ability to harness biological information. Our goal is to stimulate the development of higher computational capacity artificial intelligence systems in order to assist clinicians and support improved guidelines geared towards individualized precision medicine.
Abstract 550: Vascular And Muscle Recovery In Pre-clinical Model Of Peripheral Vascular Disease Using Intramuscular Estrogen Related Receptor Gamma Gene Therapy
Authors: Sopariwala Danesh H , Rios Andrea S , Saley Addison , Kumar Ashok , Narkar Vihang A
Published: October 2023

Peripheral arterial disease (PAD) and critical limb ischemia (CLI) are caused by occlusion of blood vessels and characterized by muscle ischemia, weakness, and limb myopathy. Over 8-12 million Americans are affected by PAD, resulting in impaired mobility, increased cardiovascular risk, and limb amputation. Therapeutic strategies for simultaneously restoring blood flow, metabolism, and muscle recovery are currently lacking for PAD. We have previously shown in a transgenic mouse model that nuclear receptor Estrogen-related receptor gamma (ERRγ) is a central regulator of muscle metabolism and angiogenesis. Here, we investigated intramuscular (IM) gene therapy for PAD using AAV9-Esrrg in unilateral hindlimb ischemia (HLI) pre-clinical model. We first established in hindlimb muscles of C57Bl6/J mice that a single IM injection of 1X10^11 AAV9-Esrrg viral particles robustly increased ERRγ protein expression, resulting in induction of angiogenic and oxidative genes, higher capillary (CD31 immunostaining) density and SDH oxidative metabolic activity over AAV9-GFP injected control muscles. Subsequently, AAV9-Esrrg injection, 24 hours after HLI, increased ischemic neo-angiogenesis, markers of endothelial activation, and significantly improved blood flow recovery measured by laser Doppler flowmetry over AAV9-GFP injected controls. Moreover, ERRγ overexpression increased mitochondrial respiratory complex protein expression, which resulted in restored SDH oxidative metabolic capacity in ischemic muscle. More critically, AAV9-Esrrg restored myofibrillar size and mitigated ischemia-induced myopathy as revealed by myofiber size to number ratio quantification. In conclusion, we demonstrate that post-ischemic IM AAV9-Esrrg gene delivery rescues ischemic pathology by boosting metabolism and angiogenesis, underscoring Esrrg gene therapy or pharmacological activation as a highly promising strategy for treating PAD/CLI-related myopathy.
Abstract 565: Ambulatory Percutaneous Coronary Angioplasty: A Resource For Low-income Countries.
Authors: Cruz Licurgo J , Gutierrez Anthony , Wu Ka , Grullon Helio , Lopez Yanely
Published: October 2023

Percutaneous coronary intervention (PCI) is today's most widely used coronary revascularization technique. By 2020, more than 965,000 PCI were performed in the United States, and an exponential increase in this type of procedure is expected. This implies a significant occupation of beds in hospital centers, with the consequent increase in waiting list time, cost per procedure, and demand for personnel resulting in lower quality of care in patients with medical emergencies. Technological advances have reduced the incidence of significant complications, and hospital stays after the intervention, allowing to consider discharge from the hospital on the same day of the procedure in selected low-complexity patients with a high satisfaction rate. Therefore, we aim to describe the short-term safety of ambulatory percutaneous coronary intervention in low-income countries.

A prospective observational single-center with a population of patients who underwent percutaneous coronary angioplasties in Santiago, Dominican Republic. between August 2019 and May 2022. Low-risk for complication patients were selected and discharged 6-12 hours after the procedure.Phone follow-up was done on the seventh and fourteenth days, with an additional follow-up on day thirty for clinical, electrocardiographic, and echocardiographic evaluation, in search of signs and symptoms of complications derived from the procedure.

With a total of 81 patients in which, 61.73% were male with a mean age of 64.74 (SD 10.98) years, 29.63% had a clinical indication for angioplasty due to stable ischemic disease, 66.67% due to unstable angina, and 3.70% due to non-ST • elevation acute coronary syndrome. As for the access, 95.06% was radial, 3.70% femoral access, and 1.23% cubital. Three patients presented punction hematomas. Only 1 (1.23%) of the patients presented dyspnea after the procedure. Only 1 (1.23%) suggested changes in the electrocardiogram, none of the participants had to interrupt the outpatient protocol and require hospital admission, and none presented signs or symptoms suggestive of worsening clinical such as less tolerance to exercise, respiratory distress, angina pectoris at rest or with exertion or changes in the echocardiogram.
Abstract 583: Validating Noninvasive Indices Of Thoracic Aortic Dissection With Magnetic Resonance Elastography
Authors: Fakhouri Faisal , Kolipaka Arunark , Raterman Brian , Gonring Dakota , Hirad Adnan , Mix Doran S
Published: October 2023

Objective:
Dissection-associated aneurysms (DAA) are the leading cause of death related to chronic Type-B aortic dissections (TBAD). Conventional imaging cannot distinguish high-risk DAAs that would benefit from early surgical intervention. We propose the feasibility of aortic stiffness as measured by magnetic resonance elastography (MRE) as a biomarker to help make this distinction. We validate MRE stiffness measures in 3D-printed PVA hydrogel phantoms with human-like dissection geometries and demonstrated the first successful application of MRE in a human thoracic aorta with a healthy volunteer.

Methods:
All phantoms had a 10% PVA true lumen and a 10%, 15%, 20%, or 25% false lumen. The phantoms and the thoracic aorta of a healthy volunteer were imaged in a 3T-MR scanner. A pneumatic driver created mechanical vibrations within the aorta. A cardiac-gated spin-echo echo planar imaging (SE-EPI) sequence was utilized. In vivo, end-diastolic images were chosen for analysis to minimize blood flow artifacts.

Results:
The MRE shear stiffness of the various PVA false lumen sides of the phantoms were 32.19, 51.48, 59.29, and 73.53 ± 2.66 kPa, respectively. Figure 1 shows the correlation (R
2
= 0.99) between MRE and rheometric stiffness measurements of the four phantoms with different PVA concentrations. Figure 2 shows MRE local frequency estimations of stiffness from the human aorta with a mean shear stiffness of 3.37±0.83kPa.

Conclusion:
We present a validation and feasibility study of MRE in the thoracic aorta. Future research will allow for developing predictive indices for TBAD DAA development.
Abstract 584: Myeloid Kruppel-like Factor 14 Mediates Sexual Dimorphism Of Abdominal Aortic Aneurysm Via Estrogen Receptor β
Authors: Wang Huilun , Zhao Guizhen , Chang Lin , Zhang Jifeng , Guo Yanhong , Chen Y. Eugene
Published: October 2023

Rationale:
Abdominal aortic aneurysm (AAA) is an irreversible degenerative disease of the abdominal aorta. Monocytes/macrophages are important mediators of inflammation and proteolysis during AAA development. In both human and rodent models, AAA has strong sexual dimorphism with a 4-6-fold higher prevalence in males than females, largely attributed to the estrogen/estrogen receptor signaling pathway. Krüppel-Like Factor 14 (KLF14) mediates anti-inflammatory response during disease pathogenesis and shows sexual heterogeneity in human genetic studies. However, whether and how KLF14 regulates sexual dimorphism during AAA progression has largely been unknown.

Objective:
Herein, we generated a novel insight into the anti-inflammatory effect and sexual dimorphic regulation of KLF14 during AAA pathogenesis.

Methods and Results:
We induced AAA model in myeloid cell-specific
Klf14
knockout mice in
ApoE
-deficient background (
Klf14
LysM
ApoE
-/-
) and their littermate control mice (
Klf14
fl/fl
ApoE
-/-
).
Klf14
deficiency in macrophages completely abrogated the sexual dimorphism observed in control mice by showing higher AAA incidence with more macrophage infiltration and more severe elastin degradation in female mice. Mechanistically, KLF14 upregulates the transcription of estrogen receptors, especially
ESR2
, in macrophages. Perhexiline, a KLF14 inducer, induces
Esr2
expression dependent on
Klf14
and exerts an anti-inflammatory effect partially dependent on
Esr2
in macrophages. Furthermore,
Klf14 or Esr2
deficiency in macrophages abolished the protective effect of exogenous estradiol (E
2
) treatment in male control mice.

Conclusions:
These studies provide evidence that
Klf14
deficiency within myeloid lineage cells accelerated AAA development in female mice, resulting in the loss of sexual dimorphism in AAA pathogenesis. KLF14 showed protective effects, likely via transcriptionally regulating
ESR2
expression and suppressing inflammation.
Abstract 585: Sivelestat Attenuates Angii-induced Abdominal Aortic Aneurysms In Apolipoprotein E-deficient Mice
Authors: Hada Yoshiko , Uchida Haruhito A , Okamoto Shugo , Otaka Nozomu , Katayama Katsuyoshi , Onishi Yasuhiro , Takemoto Rika , Takeuchi Hidemi , Umebayashi Ryoko , Wada Jun
Published: October 2023

Hypothesis:
We assessed the hypothesis that sivelestat (Siv) has a protective effect against AngII-induced AAA.

Methods:
Male apolipoprotein E-deficient mice were divided into 3 groups: vehicle+saline (n=8), AngII+saline (n=14), and AngII+Siv (n=17). All mice were infused with saline or AngII (1000 ng/kg/min) for 28 days. They were also administered intraperitoneally with either Siv (100 mg/kg) or vehicle twice daily from the infusion of pumps for 28 days. In vitro study, human aortic smooth muscle cells (HASMCs) were pretreated with Siv (100 μM) or DMSO and stimulated with 0.1 μg/ml human neutrophil elastase for 24h.

Results:
No significant difference was found in body weight and plasma concentrations of total cholesterol among the 3 groups. AngII infusion significantly increased aortic width compared to the saline group (
p
=0.011). Siv administration attenuated dilatation of aortic width (
p
=0.022). The incidence of AAAs in AngII-infused mice not administered Siv was 93%. Siv significantly decreased the incidence to 47% (
p
=0.009). Pronounced disruptions of medial layers were observed in the AngII+saline group, elastin fragmentation induced by AngII was markedly reduced by Siv. A large number of CD68 positive cells and many Gr-1 positive cells were dominantly observed in the AngII+saline group. In the Siv treatment group, few infiltrations of inflammatory cells were observed. Both pro-form and active-form MMP-2 were increased by AngII and reduced by Siv (pro-form:
p
=0.07, active-form:
p
<0.05). Both pro-form and active-form MMP-9 were increased by AngII, and only active-form MMP-9 was reduced by Siv (active-form:
p
<0.05). In the AngII 4-week infusion study, plasma elastase concentration (
p
=0.041) and its activity (
p
=0.011) were increased by AngII. These increases were significantly attenuated by Siv (concentration:
p
=0.010, activity:
p
=0.027). A significant correlation was observed between aortic width and plasma elastase activity (R=0.6976,
p
<0.0003). In vitro study, MMP-2 activity was induced by elastase, which was attenuated by Siv treatment in medium (
p
<0.01) and protein of HASMCs (
p
=0.01).

Conclusions:
Siv attenuates AngII-induced AAA in mice through inhibition of neutrophil elastase.
Abstract 598: Patients With High Bleeding Risk In A Randomized Controlled Trial Of Alert-based Computerized Decision Support For Stroke Prevention In Atrial Fibrillation: An AF-ALERT II Substudy
Authors: Khairani Candrika D , Bejjani Antoine , Armero Andre , Porio Nicole D , Krishnathasan Darsiya , Tristani Anthony , Davies Julia , Goldhaber Samuel , Piazza Gregory
Published: October 2023

Introduction:
Perceived high bleeding risk is the primary reason for withholding anticoagulation (AC) in patients with atrial fibrillation (AF). We performed AF-ALERT 2, a randomized controlled trial (RCT) of alert-based computerized decision support (CDS), to increase AC prescription in high-risk outpatients with AF.

Method:
We analyzed 397 patients in the alert group of this trial to determine the clinical characteristics and outcomes of patients. 77 patients perceived as having too high risk of bleeding were compared with 320 patients with perceived low bleeding risk.

Results:
Perceived high bleeding risk was the main reason providers omitted AC (19.3%). Patients with high bleeding risk were 36.4% women and had a mean age of 78. Median of CHA
2
DS
2
VASc and HAS-BLED were similar in patients with high and low bleeding risk (median (IQR) 4(2-7) vs 3(2-8) and median (IQR) 3(2-5) vs 3(1-5), respectively) (Figure). Higher median HAS-BLED was associated with higher rates of clinically relevant non-major bleeding (CRNMB) (
p
=0.03). Patients with perceived high and low bleeding risk received similar rates of AC at 90 days (14.3% vs 18.4%,
p
=0.44). Major and CRNMB rates were similar between the two groups.

Conclusion:
In a trial of alert-based CDS, perceived bleeding risk was the most common reason for omitting AC prescriptions in patients with AF. Despite having similar median HAS-BLED, patients with perceived high bleeding risk had similar rates of AC prescription to those deemed low bleeding risk.
Abstract 609: Heterozygous Tissue Factor Deficiency Protects Against Factor VII Activation And Consumption In A Murine Endotoxemia Model
Authors: Brake Marisa A , Schulman Sol
Published: October 2023

Background:
At least 1 in 25,000 humans carry
F3
null alleles predicted to cause heterozygous tissue factor (TF) deficiency. Mice with heterozygous TF deficiency (
F3
+/-
) exhibit increased bleeding times and reduced thrombus formation in some models, and are protected against lethal thrombosis in penetrant thrombophilia. TF supports the activation of factor VII (FVII)
in vitro
, an effect that is evident
in vivo
in the extreme case of low-TF mice expressing ~1% of basal TF levels.

Aim:
To determine the impact of heterozygous TF deficiency on FVII activation
in vivo
.

Methods:
Citrated plasma was isolated via inferior vena cava blood draw from
F3
+/-
and wildtype littermate mice at 10-11 weeks of age. To induce coagulation activation through endotoxemia, mice were challenged with intraperitoneal injection of 8 mg/kg LPS for 6 hours. Plasma TF was determined by ELISA. FVII and FVIIa levels were measured by FVII activity and Staclot VIIa-rTF clotting assays, respectively. n≥10 mice in all experiments.

Results:
F3
+/-
mice have significantly reduced plasma TF antigen levels compared to wildtype littermate controls under basal conditions (6.5 pg/mL vs 11.6 pg/mL, p<0.001), differences that persist following endotoxemic challenge (9.9 pg/mL vs 14.8 pg/mL, p<0.001). At baseline,
F3
+/-
mice had similar circulating levels of zymogen FVII and FVIIa compared to controls. However, the levels of FVIIa correlated with FVII activity levels in
F3
+/-
mice (r
2
=0.66, p=0.003), whereas no correlation between FVIIa and FVII activity levels was observed in controls (r
2
=0.17, p=0.23). During endotoxemia,
F3
+/-
mice maintained significantly higher total FVII (85.6% vs 66.1%, p<0.05) and FVIIa (52.9% vs 35.4%, p<0.05) as compared to controls.

Conclusions:
FVII and FVIIa levels are unaffected by heterozygous TF deficiency in healthy mice, but FVIIa levels are dependent on the amount of FVII when TF is limiting. When TF expression and coagulation activation are augmented as during endotoxemic challenge,
F3
+/-
mice are protected against aberrant FVII activation and consumption. These studies suggest that human genetic variation influencing TF dosage could influence FVII activation and disease outcomes.
Abstract 610: Using Bicarbonate Based Purge Solution As The Sole Anticoagulation Strategy In Impella 5.5-a Novel Approach
Authors: Halder Anupam , Rajak Kripa , Goswami Rohan , Atrash Anas
Published: October 2023

The Impella® (Abiomed; Danvers, MA) pumps are percutaneous, transvalvular mechanical circulatory support (MCS) devices that propel blood from left ventricle to aorta that are used to augment cardiac output in management of high-risk percutaneous coronary intervention (HRPCI), acute heart failure, or cardiogenic shock. These systems utilize a flow of purge fluid that runs countercurrent to the blood flow which prevents inline thrombosis and protein deposition. Guidelines generally recommend heparin-dextrose purge fluid, with BBPS reserved for patients with heparin intolerance or active bleeding. We present the first case of use of BBPS as an elective choice for purge fluid in a patient with severe cardiogenic shock.Patient is 56-year-old male with known history of hypertension, diabetes and hyperlipidemia who presented with acute onset shortness of breath secondary to acute heart failure in the setting of myocardial infarction. He underwent a HRPCI for a non revascularizable three vessel coronary artery disease. He was readmitted for cardiogenic shock complicated with ventricular tachycardia, fibrillation and high risk of sudden cardiac death, necessitating inpatient transplant evaluation. Left heart catheterization showed pulmonary artery pressure of 59/63, wedge of 29 and cardiac index of 2 on 0.125mcg/kg/hr of milrinone. He received aggressive diuresis, antiarrhythmics and inotropic support. With increasing milrinone requirement, Impella 5.5 was placed and his antiplatelet regimen was changed from oral prasugrel to intravenous cangrelor with aspirin. A clinical decision was made to use BBPS instead of heparin purge, based on institutional experience and clinical data. Purge pressure, flow, lactate dehydrogenase and hematocrit have remained stable about 1.5ml/hr, 500mm Hg, 230U/L and 30% respectively for 22 days post-impella placement as the patient awaits transplantation.Limited retrospective studies and animal data, have shown no change in purge pressure/flow with BBPS. However, most of the data remains limited to use in heparin-intolerant patients. Our experience has indicated the possibility to use BBPS without systemic anticoagulation with no short-term complication,however conclusive trial data needs to be generated.
Abstract 611: Effect Of Tumor-derived Extracellular Vesicles On Platelet Function
Authors: Kottana Regina Komal , Papa Anne-Laure
Published: October 2023

Tumor-derived extracellular vesicles (EVs) have been described as pro-coagulant particles causing cancer-associated thrombosis. Tumor-derived EVs circulating in the bloodstream may interact with platelets or trigger the coagulation cascade, leading to venous and arterial thrombosis. In order to better understand the interaction of EVs with the hemostatic components, we aim to determine the mechanistic aspects of their interaction with platelets and their potential role in initiating coagulation. Given the wide variation of protein and integrin expression between different cancer cell types and the expectation of varying mechanistic effects, we have selected to study lung (A549), breast (MDA-MB-231) and glioblastoma (LN18) cell lines. We have characterized the effect of EVs derived from these cell lines on platelet function of aggregation and activation. Our data shows that both A549 and MDA-MB-231 EVs at 50 ug/mL significantly increase platelet aggregation as compared to control when incubated with the platelets for 10 min and in the presence of an agonist (ADP 20 uM) (Fig. 1). We confirmed the expression of phosphatidylserine on the surface of EVs using Annexin V and flow cytometry, indicating that they are pro-coagulant in nature. Furthermore, we will be investigating interaction of EVs with platelet receptor GP IIb-IIIa, agonist release, and presence of proteins such as Tissue Factor, as possible mechanisms for EV-induced platelet aggregation. Thus, the understanding of the mechanistic aspects behind the interaction between EVs and the hemostatic components could prove beneficial in the design of next generation agents for cancer-associated thrombosis.

Figure 1. Platelet aggregation measured by light transmission aggregometry with ADP 20uM in the presence of A549 and MDA-MB-231 EVs (n=8 to 11)
Abstract 635: ESAM Deficiency-related Coronary Microvascular Dysfunction Contributes To Left Ventricle Diastolic Dysfunction In HFpEF
Authors: Bagi Zsolt , Buncha Vadym
Published: October 2023

Coronary microvascular dysfunction and vascular inflammation have been linked to heart failure with preserved ejection fraction (HFpEF), but the underlying molecular mechanisms remain incompletely understood. Endothelial cell-selective adhesion molecule (ESAM) has been recently implicated as one of the biomarkers for heart failure. The biological function of ESAM is to regulate inflammatory cell adhesion, permeability and angiogenesis. Here, we examined the mechanistic role of ESAM in contributing left ventricle (LV) diastolic dysfunction in a mouse model of human HFpEF. We employed wild type (WT) mice and mice with homozygous genetic deficiency of ESAM (ESAM
-/-
), with or without uninephrectomy and aldosterone infusion (UNX-Aldo, for 4-week). Using echocardiography, we found that WT mice with UNX-Aldo develop LV diastolic dysfunction, as indicated by a significantly reduced E/A ratio (E=early, A=late mitral inflow peak velocities), increased E/e’ ratio, isovolumic relaxation time (IVRT) and E wave deceleration time. UNX-Aldo significantly increased the serum soluble ESAM levels, along with elevated MMP2/9 levels, as potential mediators of ESAM ectodomain shedding. When compared to WT, ESAM
-/-
mice with UNX-Aldo displayed significant worsening of LV diastolic dysfunction, as indicated by increased IVRT, and the development of pulmonary edema and fibrosis. An unbiased automated tracing and 3D reconstruction of coronary microvasculature revealed that ESAM
-/-
mice had a significantly reduced coronary microvascular density. Arteries of ESAM
-/-
mice exhibited impaired endothelial sprouting and in cultured endothelial cells siRNA-mediated ESAM knockdown reduced tube formation. Thus, we propose that ESAM plays a role in the proper myocardial vascularization, hence the maintenance of myocardial perfusion. Deficiency, or augmented ectodomain shedding of ESAM impairs myocardial vascularization, whereby it contributes to the development of LV diastolic dysfunction, and could have mechanistic and diagnostic implications in human HFpEF.
Abstract 652: In Vitro Implication Of Mechanisms Mediating Ultrasound-enhanced Vascular Permeability
Authors: Islam Afsana , Peng Tao , McPherson David D , Klegerman Melvin E
Published: October 2023

Background:
We have previously shown modeling of ultrasound (US) enhancement of echogenic liposome (ELIP) penetration into the arterial wall using a transwell culture system featuring a human umbilical vein endothelial cell (HUVEC) monolayer. We found the effect was due to US radiation pressure rather than cavitation, mediated by nitric oxide (NO) signaling, and that it did not exclusively require cGMP production. We have now conducted an initial investigation to identify mechanisms mediating this effect.

Hypothesis:
US radiation pressure impacts the cell-surface receptor involved in blood pressure compensation and shear stress-induced NO production, mediated by Akt phosphorylation.

Methods:
HUVEC were grown to confluence in a 6-well culture plate, which was subjected to continuous-wave US (Sonitron) for various times from 0 to 50 seconds. Following an additional 30 minutes of incubation at 37
o
C, cells in each well were harvested with 100 μl lysis buffer. Lysates were subjected to SDS-PAGE and Western blotting with primary antibodies, followed by secondary antibodies coupled to IR dyes. Blots were visualized with the LI-COR Odyssey Imaging System and quantitated by densitometric analysis with NIH ImageJ software.

Results:
US treatment of HUVEC caused phosphorylation of Akt and ERK 1/2, at an optimum at 30 seconds of treatment (Fig. 1).

Conclusions:
The hypothesis was supported, implicating shear stress-induced stimulation of the mitogen-activated protein kinase cascade, involving activation of both Akt and ERK 1/2. In the future, we will investigate pathway initiation and endpoints.