Abstract 4142424: The impact of the stress hyperglycemia ratio on adverse prognosis in patients with chronic thromboembolic pulmonary hypertension

Circulation, Volume 150, Issue Suppl_1, Page A4142424-A4142424, November 12, 2024. Background:Risk assessment for chronic thromboembolic pulmonary hypertension (CTEPH) remain challenging. Stress hyperglycemia represents the regulation of glucose metabolism in response to stress. Meanwhile, stress hyperglycemia ratio (SHR) is recently found to reflect true acute hyperglycemic status. However, the relationship between SHR and adverse prognosis is uncertain. This study aimed to investigate the prognostic value of SHR in CTEPH patients.Methods:A total of 451 CTEPH patients with available baseline SHR measurement were enrolled between February 2014 to July 2023 at Fuwai hospital. The predictive values of SHR for adverse events were assessed.Results:During a median follow-up of 21 months, 89 (19.7%) CTEPH patients experienced adverse clinical outcomes. Kaplan-Meier curve analysis revealed that the cumulative adverse event rates were significant higher in the SHR≥0.747 with CTEPH patients, compared with patients in the SHR

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Novembre 2024

Abstract 4140558: Circulating plasma proteins in the Fontan circulation predict mitochondrial oxidative stress

Circulation, Volume 150, Issue Suppl_1, Page A4140558-A4140558, November 12, 2024. Background:Single ventricle congenital heart disease such as hypoplastic left heart syndrome (HLHS) with a Fontan circulation constitute the largest group of children hospitalized with circulation failure, experiencing an in-hospital mortality rate of 20-50%. We investigated the mechanisms leading to circulation failure so as to identify novel therapeutic targets.Methods:Blood was collected from patients with HLHS s/p Fontan and controls with normal cardiac anatomy and function (N=6/group). Plasma microvesicles (MV) were isolated, and proteomics assessed using data independent acquisition mass spectroscopy. Dysregulated proteins with a fold change >1.5 or < -1.5, p

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Novembre 2024

Abstract 4142430: Feasibility of Coronary Allograft Vasculopathy Assessment Using Cardiac Stress Magnetic Resonance Imaging with Fully Quantitative Myocardial Blood Flow

Circulation, Volume 150, Issue Suppl_1, Page A4142430-A4142430, November 12, 2024. Background:Cardiac allograft vasculopathy (CAV) is a major cause of morbidity and mortality following heart transplantation (OHT). Noninvasive methods to detect CAV and risk stratify OHT patients are needed. The value of fully quantitative stress cardiac magnetic resonance imaging has been recently validated and may be a promising technique for OHT surveillance. We aimed to evaluate the feasibility of quantitative stress CMR after OHT.Methods:We enrolled asymptomatic OHT recipients without coronary artery disease to undergo regadenoson stress CMR (1.5T GE HealthCare) with cine imaging, tissue mapping, and late gadolinium enhancement (LGE) imaging for routine CAV surveillance. Using the dual sequence technique, quantitative perfusion values were determined using Fermi deconvolution. Myocardial perfusion reserve (MPR) was calculated as the ratio of stress to rest myocardial blood flow (MBF).Results:Fifty-three subjects (mean age 47.06 ± 17.14 years) were included. OHT recipients (n=11, mean 6.77 ± 4.34 years post-transplant) were compared with healthy controls (n=43). No life-threatening adverse events, brief or prolonged atrioventricular block or other arrhythmias occurred with regadenoson. Coronary angiography was performed in 9 OHT patients before CMR, with an average of 1.99 ± 2.05 years between studies. No visual inducible ischemia was reported. Post OHT, rest MBF was significantly higher (1.69 ± 0.52 mL/g/min vs 1.01 ± 0.24 mL/g/min, p=0.004) and stress MBF was lower (2.33 ± 0.69 mL/g/min vs 2.95 ± 0.88 mL/g/min, p=0.02) compared to controls. MPR was significantly lower in OHT recipients compared to controls (1.46 ± 0.51 vs 3.11 ± 1.12, p

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Novembre 2024

Abstract 4147100: The Association between Perceived Stress and Left Ventricular Mass Index (LVMI)

Circulation, Volume 150, Issue Suppl_1, Page A4147100-A4147100, November 12, 2024. Introduction:Perceived stress is known as the feeling of uncontrollability in one’s life and the inability to cope with the amount of stress one is experiencing due to one’s circumstances. There is evidence indicating that perceived stress may be a risk factor for cardiovascular disease (CVD). However, it is unclear whether perceived stress is associated with higher left ventricular mass index (LVMI), a measure of target organ damage and strong predictor of CVD.Aim:We examined the association between perceived stress and LVMI.Methods:The Masked Hypertension Study is a multi-site study that assessed the prevalence and predictors of masked hypertension in working adults from the New York Metropolitan area. A total of 1011 participants were recruited for the study; 826 participants completed the Perceived Stress Scale questionnaire and an echocardiogram. The perceived stress scale is a 14-item likert scale that assesses different situations that affects our perceived stress or our feelings in certain situations. It has a scale of 1 to 5 with 1 being never to 5 being very often. LVMI was determined according to the 2D method based on the American Society of Echocardiography (ASE) recommendations.Linear regression models were specified predicting LVMI from perceived stress. Covariates were sex, race/ethnicity, age, BMI, systolic bp, diastolic bp, and caregiving status.Results:Of the 826 participants, 40.7% were male, 6.9% were Black, 11.9% were Hispanic/Latinx , and 48.79% were caregivers. Mean (SD) age was 45.3 (10.3) years, mean body mass index was 27.6 (5.3) kg/m2, and mean SBP and DBP were 114.7 (12.0) and 74.8 (8.5). Mean perceived stress score was 21.8 (7.6) and mean LVMI was 63.3 (15.7) gm/m2.Contrary to our hypothesis, perceived stress was not significantly associated with LVMI, B = -0.00, 95% CI: -0.13, 0.13, p= 0.98.Conclusion:There was not an association between perceived stress and LVMI. Future research should examine whether other types of stresses/stressors are related to LVMI and the implications of this for patients and their health.

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Novembre 2024

Abstract 4144217: Ruling-out Left Main Stem Stenosis By Clinical And Stress-ECG Variables: The MASTER Case-Control Multicenter Study

Circulation, Volume 150, Issue Suppl_1, Page A4144217-A4144217, November 12, 2024. Background:The ISCHEMIA trial questioned revascularization in chronic coronary syndrome (CCS) patients, but excluding subjects with left main (LM) coronary artery disease (CAD). A widely available diagnostic method excluding LMCAD would expand the implementation of an initial noninvasive strategy.Objective:Assessing the ability of excluding LMCAD through clinical and ECG stress testing (EST) variables in patients undergoing coronary angiography (CAG) for CCS.Methods:In a multicenter retrospective case-control study we evaluated CCS subjects undergoing CAG after a maximal EST.Caseswere patients with angiographic ≥50% LM stenosis or ≥70% stenoses of both proximal left anterior descending and proximal circumflex arteries; we matched them with similar patients without LMCAD (Controls)in a 1:3 ratio. Models were internally validated through logistic regressions.Results:219Caseswere matched with 554Controls. The c-statistic was 0.80 (optimism-adjusted: 0.73). Assuming LMCAD prevalence of 5% and a misclassification cost ratio of 1:100 (ratio of the cost of performing CAG in a subject without LMCAD to the cost of not performing CAG in a patient with LMCAD), the negative predictive value was 98.6%, correctly classifying 84.5% ofCases. CAG could be spared in 57.0% of subjects, missing one LMCAD diagnosis every 70 CAGs spared in patients without LMCAD (Figure).Conclusions:Among patients with CCS, LMCAD can be predicted withacceptablediagnostic accuracy anda very highnegative predictive value through a model based on clinical and EST parameters, allowing an initial noninvasive management of most patients able to perform an EST, reducing the costs of routine coronary imaging. Such results should enlarge the applicability of the ISCHEMIA results when coronary computed tomography angiography, used in ISCHEMIA, is not available, limiting the referral to invasive CAG.

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Novembre 2024

Abstract 4143847: CRISPR screening identifies critical factors regulating DNA damage response in human cardiomyocytes under oxidative stress

Circulation, Volume 150, Issue Suppl_1, Page A4143847-A4143847, November 12, 2024. Introduction:Our previous studies have shown that sustained activation of the DNA damage response (DDR) in cardiomyocytes leads to p53/p21 activation and cardiac dysfunction. Although the DDR generally involves molecules in DNA replication and repair pathways, the non-proliferative nature of cardiomyocytes suggests a cardio-specific DDR mechanism. However, our understanding of DDR in cardiomyocytes remains limited. Here, we aim to use CRISPR interference (CRISPRi) knockdown screens to identify genes critically involved in DDR regulation in human cardiomyocytes. We hypothesize that identifying these gene clusters may allow us to develop methods to prevent cardiac dysfunction by suppressing DDR in cardiomyocytes.Methods and Results:We established a human iPS cell line stably expressing dCas9-KRAB, which allows CRISPRi-mediated gene knockdown, and differentiated the cells into cardiomyocytes. The resulting human iPS cell-derived cardiomyocytes (hiPSCMs) showed the achievement of approximately 80% knockdown efficiency after gRNA transfection. We stimulated the hiPSCMs with H2O2and quantitatively evaluated the expression levels of the DDR markers γH2AX and p21 by immunostaining using the Operetta®high content imaging system. The DDR markers showed a significant concentration-dependent increase in response to H2O2administration. For arrayed CRISPRi screening, we constructed a gRNA library targeting 437 DDR-related genes. Using this library, we knocked down each DDR-related gene in hiPSCMs followed by H2O2stimulation. We quantified the expression levels of DDR markers by calculating the fluorescence intensity ratios relative to control after gene knockdown, and standardized them to calculate Z scores for all 437 genes. The screening successfully revealed the differential impact of each gene knockdown on γH2AX and p21 expression. We identified 71 genes that significantly affected their expression (Z-score < -1 or > 1). Mapping these genes to DDR pathways highlighted the differential impact of gene knockdown within the same pathway, and stratified their importance in cardiomyocytes.Conclusions:Arrayed CRISPR screening using hiPSCMs revealed differential functional significance of DDR-related genes in cardiomyocytes, identifying 71 genes of particularly significant importance. These findings provide a critical understanding of the cardio-specific DDR pathway and important clues for establishing an appropriate method to suppress DDR in the failing heart.

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Novembre 2024

Abstract 4140852: Total Burden of Posttraumatic Stress Disorder on Incident Cardiovascular Disease Among Women Veterans

Circulation, Volume 150, Issue Suppl_1, Page A4140852-A4140852, November 12, 2024. Introduction:Posttraumatic stress disorder (PTSD) is an independent cardiovascular disease (CVD) risk factor with high prevalence in women, particularly women veterans (WV). While the impact of PTSD on ischemic heart disease (IHD) and stroke has been well established, its impact on a comprehensive set of CVD outcomes has not been studied in WV, a growing population at high risk for CVD in the U.S. The goal of this project was to investigate the impact of PTSD on a comprehensive set of CVD conditions in WV.Methods:National Veterans Health Affairs (VHA) electronic health records were used to identify all women who visited any VAs from 1/1/2000 to 12/31/2019. PTSD and CVD were identified based on International Classification of Disease versions 9 and 10 diagnoses ( 1 inpatient or 2 outpatient encounter documentations). Incident CVD outcomes included first onset of IHD, stroke, cardiomyopathy/heart failure (HF), pulmonary arterial hypertension/pulmonary hypertension (PH), atrial flutter/fibrillation (AF), peripheral arterial disease (PAD), venous thromboembolism (VTE), and aortic stenosis (AS). Propensity score matching and Cox survival analyses were performed to assess associations of PTSD with incident CVD outcomes.Results:We identified 622,312 WV, with 140,210 (22.53%) with PTSD. After 1:1 matching, 202,896 patients were included in the final analysis. WV had a mean age of 39.1 years, and the mean [MOU1] follow-up was 5.72 years. Table 1 reveals the association of PTSD with an incident CVD composite and the different component outcomes individually.Conclusion:In a large sample of WV, we demonstrate significant and clinically relevant associations of PTSD with a comprehensive set of incident CVD outcomes. The potential association with some of the specific outcomes warrant further investigation. Maybe more of a call to action for PTSD screening and treatment to potentially offset CVD risk instead?

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Novembre 2024

Abstract 4140462: Effects of Right Ventricular vs. Conduction System Pacing on Left Ventricular Systolic and Diastolic Function Reserve and Pulmonary Gas Exchange During Exercise Stress in Pacemaker Dependent Patients with Normal Left Ventricular Ejection Fraction

Circulation, Volume 150, Issue Suppl_1, Page A4140462-A4140462, November 12, 2024. Background:Right ventricular pacing (RVP) can have adverse cardiac effects and cause pacing induced cardiomyopathy (PiCM). His bundle pacing (HBP)&Left Bundle Branch area pacing (LBBAP) mimic physiologic conduction (PhysioP) and maintain biventricular synchrony.Hypothesis and Aims:Reduced left ventricular (LV) systolic function reserve in the presence of normal baseline LV ejection fraction (EF) could precede development of RV PiCM. Our aim was to compare the effects of RVP vs. PhysioP on bicycle exercise cardiopulmonary performance in patients with normal LVEF who required pacing for bradyarrhythmias.Methods:Patients with sinus rhythm and RVP or PhysioP&ventricular pacing burden of >70% who completed cardiopulmonary exercise test and simultaneous stress echocardiography (SE) were included. Pulmonary gas exchange was calculated using Ventilation/CO2 production at rest and during exercise. Changes in LV size, EF, longitudinal strain and diastolic function and gas exchange parameters were compared post and pre exercise in the 2 groups.Results:25 of 29 patients completed the study [68 ± 23 yrs, 48% M; LVEF 56±5%, 11 RVP, 14 PhysioP]. There was no difference in baseline demographic&clinical variables, exercise duration, rest and peak heart rate and blood pressure between 2 groups. Pacing duration was 2.61±1.48 yrs in RVP vs. 0.84±0.67 yrs (p=0.003) in the Physio group. Resting echocardiographic parameters (Table 1A)were comparable. Compared to RVP, reduction in LV end-diastolic volume (EDV) 3.4±14.1 ml vs. -23.1±18.1ml, p=0.006)&LV end-systolic volume (ESV -5.7±11.6 ml vs. -18.0±9.5ml, p=0.01) was more pronounced in the PhysioP group. Changes in LVEF, LV strain&diastolic function were not different between the 2 groups (Table 1B). There were no significant differences in changes in pulmonary gas exchange parameters in the 2 groups.Conclusions:In patients with normal LVEF and pacemaker dependent, RVP is associated with impaired but PhysioP with preserved LV systolic function reserve, which can be detected by exercise SE. SE may help identify patients at risk for RV PiCM. Benefit of PhysioP needs to be determined by larger studies with longer follow-up.

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Novembre 2024

Abstract 4137913: Role of serial evaluation of myocardial inflammatory activity and oxidative stress in determining the therapeutic efficacy of immunosuppression and clinical outcome in patients with cardiac sarcoidosis

Circulation, Volume 150, Issue Suppl_1, Page A4137913-A4137913, November 12, 2024. Background:Cardiac sarcoidosis (CS) was characterized by formation of granulomas in the heart. Enhancement in myocardial inflammatory activity and oxidative stress is a crucial cause of major cardiovascular adverse events (MACE). Although immunosuppressive therapy is recommended for active CS, there is no established markers for treatment and prognosis.Hypothesis:We hypothesized that the inflammation and oxidative stress in heart were associated with MACE after steroid therapy.Aims:We identified prognostic markers for MACE in patients with CS after steroid therapy.Methods:This study was a prospective observational cohort study. Patients with CS diagnosed according to Japanese criteria were enrolled in this study. Patients with abnormal accumulation of18F-FDG in heart were treated with steroids with standard guideline-recommended protocol.18F-FDG PET were performed after more than 6 months of induction. Urinary 8-hydroxy-2′-deoxyguanosine (U-8-OHdG), a marker of oxidative DNA damage, and indices of cardiac and renal function were measured. The major outcome was a composite of the first sustained ventricular tachycardia (sVT) /sudden cardiac death (SCD), hospitalization for heart failure, and radiological relapse with exacerbation of clinical manifestation.Results:Fifty consecutive patients with CS underwent steroid therapy and followed up (median follow-up period of 58 months). 39 of 50 patients underwent 18F-FDG PET/CT more than 6 months after steroid therapy. During the follow-up period, 17 of 39 patients showed MACE, consisting of sVT/SCD (N= 11), hospitalization (N= 2) and radiological relapse (N= 4). A Cox proportional-hazard model showed that the U-8-OHdG and SUV max value of FDG-PET were independent predictors of MACE. ROC analysis revealed that the cut-off values of U-8-OHdG and SUV max for predicting the MACE were 11.6 ng/mg Cr (AUC 0.913, sensitivity 86.7%, specificity 90.0%) and 4.64 (AUC 0.878, sensitivity 76.5%, specificity 91.0%), respectively (Fig.1). Patients with a U-8-OHdG ≧11.6 ng/mg Cr or SUV max ≧4.64 had a significantly higher MACE risk (P values for U-8-OHdG and SUV max were both 0.001 by Log Rank analysis) (Fig.2). It is noted that U-8-OHdG

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Novembre 2024

Abstract 4142510: Impact of Stress Hyperglycemia Ratio on Heart Failure and Atherosclerotic Cardiovascular Events After Acute Myocardial Infarction

Circulation, Volume 150, Issue Suppl_1, Page A4142510-A4142510, November 12, 2024. Background:An acute hyperglycemic status is reportedly associated with poor prognosis in patients with acute cardiovascular diseases. Although the stress hyperglycemia ratio (SHR) is a novel index to accurately represent the hyperglycemic condition on admission, relations between SHR and clinical outcomes are not fully evaluated in a setting of acute myocardial infarction (MI).Methods:This retrospective, multicenter registry study included 2,386 patients with acute MI undergoing percutaneous coronary intervention. SHR was calculated as a blood glucose level on admission divided by the estimated average glucose derived from a glycated hemoglobin level. The co-primary endpoints of this study included heart failure (HF)-related events (a composite of all-cause death and worsening and hospitalized HF) and major atherosclerotic cardiovascular events (MACE) (a composite of all-cause death, recurrent MI, and ischemic stroke), during the index hospitalization and after discharge.Results:Of the 2,386 patients, 890 (37.3%) had diabetes, and the median SHR was 1.17 [0.99, 1.45]. HF events and MACE occurred in 680 (28.5%) and 233 (9.8%) during hospitalization. SHR was identified as a factor significantly associated with both in-hospital HF events (adjusted odds ratio 1.65, 95% confidence interval 1.18-2.29, p=0.003) and MACE (adjusted odds ratio 1.50, 95% confidence interval 1.10-2.03, p=0.009). Among 2,017 patients who survived to discharge and had follow-up information, 195 (9.7%) and 214 (10.6%) experienced HF events and MACE during the median of 536 days after discharge. Patients with the high SHR ( >1.45, 4th quartile) had an increased risk of HF events than those with SHR ≤1.45, while the incidence of MACE after discharge did not differ significantly between the two groups (Figure). The multivariable analysis confirmed the association of SHR with long-term HF events.Conclusions:In patients with acute MI, SHR was predictive of in-hospital outcomes including HF events and MACE, while after discharge, the higher SHR was associated with a higher HF risk but not with MACE. Further studies are needed to elucidate the underlying mechanisms and potential incremental benefit of SHR in stratifying patient risks after MI.

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Novembre 2024

Abstract 4146699: Blunted Hemodynamic Reactivity to Acute Mental Stress in the Lab is Associated with Autonomic Inflexibility at Home

Circulation, Volume 150, Issue Suppl_1, Page A4146699-A4146699, November 12, 2024. Background:Growing evidence suggests that blunted blood pressure and heart rate responses to acute psychological stress independently associate with an increased risk of adverse outcomes in individuals with CHD, but assessment of mental stress reactivity in clinical settings is resource intensive. An alternative approach is to passively measure stress physiology at home with wearables, which is easier to translate into clinical practice. We tested the hypothesis that blunted mental-stress hemodynamic reactivity in the lab is associated with digital biomarkers of autonomic inflexibility at home.Methods:We conducted a mental stress test in 239 participants (age < 60 years) with an MI within 8 months. Participants underwent a speech stressor task in front of an audience to induce mental stress, during which blood pressure and heart rate were measured repeatedly during a baseline 15-minute rest period and 5-minute stress challenge. Participants went home with a 7-day Holter monitor to measure autonomic function. We examined vagal autonomic inflexibility with deceleration capacity (DC), a digital biomarker calculated via phase rectified signal averaging of heart rate intervals. We also examined low frequency (LF) heart rate variability (HRV), an indirect measure of baroreceptor sensitivity. We measured mean values from 5-minute windows during sedentary periods only to avoid confounding due to physical activity. We used multivariable linear regression models to adjust for potential confounding due to age, beta-blockers, and sex.Results:The mean age was 52 years, 51% were black, and 36% were women. Lower DC most strongly associated with a blunted change in heart rate during acute mental stress challenge (adjusted p

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Novembre 2024

Abstract 4140555: Sleep Quality Mediates the Relationship Between Sleep Hygiene Practices and Psychological Stress Among Adults With Multiple Cardiovascular Risk Factors

Circulation, Volume 150, Issue Suppl_1, Page A4140555-A4140555, November 12, 2024. Background:Psychological stress and poor sleep quality are interrelated and disproportionately affect adults who have multiple risk factors of cardiovascular disease (CVD). Sleep hygiene practices, such as maintaining an optimal household environment and engaging in healthy bedtime behaviors, are essential to sleep health. These practices may also impact psychological stress; however, their relationships remain under-studied. This study aimed to examine the associations among sleep hygiene practices, sleep quality, and psychological stress in adults with multiple CVD risk factors.Methods:Adults diagnosed with hypertension and type 2 diabetes completed an online survey (N = 300). Psychological stress and sleep quality were assessed using the Perceived Stress Scale 4 and the Pittsburgh Sleep Quality Index, respectively. A sleep hygiene instrument was used to examine 8 individual factors focusing on negative household environment (safety, physical comfort, temperature, and light) and poor in-bed behaviors (watching TV, playing video games, using screens, and eating). Multiple regression was employed to examine the association of each sleep hygiene factor with sleep quality and psychological stress. Subsequently, mediation analyses were conducted to examine the mediating role of sleep in the association between the composite sleep hygiene score and psychological stress.Results:Of the sample, 78% reported poor sleep quality and 44% reported high psychological stress. Individual sleep hygiene factors (e.g., unsafe household and eating at bedtime), as well as the composite sleep hygiene score, were significantly associated with poorer sleep quality and higher psychological stress. Sleep quality partially mediated the association between the composite sleep hygiene score and psychological stress (Indirect effect: 0.183; 95% bootstrap confidence interval: 0.057-0.339).Conclusions:The findings showed strong links between sleep hygiene practices, sleep quality, and psychological stress. Although causality cannot be inferred, current evidence suggests that promoting sleep hygiene education and implementing strategies to enhance sleep quality may alleviate psychological burdens in adults with multiple CVD risk factors.

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Novembre 2024

Abstract 4142206: Shear Stress-based Purification Method for Human Pluripotent Stem Cell-derived Endothelial Cells

Circulation, Volume 150, Issue Suppl_1, Page A4142206-A4142206, November 12, 2024. Background:To apply human pluripotent stem cell-derived endothelial cells (hPSC-ECs) in regenerative medicine, exploring methods for highly purified ECs is desirable. Cell sorting is a versatile technique for isolating and purifying specific cell types, yet mechanical cell loss persists. Previously, we established a differentiation method for human induced pluripotent stem cell-derived ECs (hiPSC-ECs) based on lineage control using vascular endothelial growth factor (VEGF) and 8-Bromo cyclic adenosine monophosphate (cAMP). However, achieving high hiPSC-ECs purity without cell sorting has not yet been possible.Hypothesis:We speculated that applying digital rocker-generated shear stress during a specific period of hiPSC-EC induction would yield highly purified hiPSC-ECs without cell sorting.Methods:We applied cyclic share stress to the cultured cells using a digital rocker. To optimize the frequency and duration of digital rocker application, ECs purity on day 13 of differentiation (d13) was analyzed by flow cytometry for vascular endothelial cadherin (VE-Cadherin). Shear stress was measured using a simulation model. The functionality of ECs was evaluated through reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) for endothelial nitric oxide synthase (eNOS) and angiogenesis assay.Results:The optimized protocol consisted of a rocking period from day 5 (representing the EC progenitor stage) to d13, at 30 cycles/min with 13° tilt (equivalent to 1.09 dyn/cm2), which significantly increased the purity of ECs (Control vs Rocking: VE-Cadherin; 69.25±17.43 vs 86.68±6.023 %, P = 0.0090). Examining the number of cells on d13 revealed rocking stimulation reduced both ECs and non-ECs. Non-ECs were nearly absent, suggesting EC purification occurs by removing non-ECs, indicating ECs are more resistant to being eliminated by the rocking stimulation. The rocking culture also led to increased eNOS mRNA expression on d13 (Control vs Rocking: 0.5574±0.4985 vs 1.056±0.1652, P = 0.0393). The angiogenesis assay showed a longer vascular structure length trend in the rocking group, indicating enhanced angiogenic capacity. (Control vs Rocking: 15407±2929 vs 18335±3568 Pixel, P= 0.4309).Conclusion:In this study, we developed a method where digital rocker-generated shear stress during a specific period of hiPSC-EC induction not only selectively purifies ECs without cell sorting, but also enhances endothelial function, demonstrating their therapeutic potential.

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Novembre 2024

Abstract 4137735: Chronic Oxidative Stress Induces Hypertension and Abdominal Aortic Aneurysm in Chemogenetic Mice Model

Circulation, Volume 150, Issue Suppl_1, Page A4137735-A4137735, November 12, 2024. Background:Aortic aneurysms account for ~10,000 deaths annually in the USA. Oxidative stress is implicated in both abdominal (AAA) and thoracic (TAA) aneurysm formation, but the mechanisms are incompletely understood. We used a chemogenetic approach to modulate oxidative stress in the vascular wall by creating a transgenic mouse (DAAO-TGTie2) that expresses yeast D-amino acid oxidase (DAAO) driven by the endothelial Tie2 promoter. DAAO generates the reactive oxygen species hydrogen peroxide from D-amino acids. Vascular tissues contain L-amino acids, so yeast DAAO is quiescent until DAAO-TGTie2mice are provided with D-amino acids. Here we characterize the cellular and molecular consequences of vascular oxidative stress in DAAO-TGTie2mice.Hypothesis:Chronic oxidative stress in the vascular wall causes arterial dysfunction.Aim:To characterize the phenotype of DAAO-TGTie2mice after oxidative stress induction in vascular endothelium.To identify the mechanisms whereby vascular oxidative stress causes arterial dysfunction and hypertension.Methods:Systolic blood pressure and aortic sonography were measured weekly in D-alanine-fed DAAO-TGTie2. Proteomic analyses were used to identify mechanistic targets, which were validated using biochemical and immunohistochemical methods.Results:D-alanine-fed DAAO-TGTie2mice develop systolic hypertension and abdominal but not thoracic aortic aneurysms; treated mice die in >3 months with burst abdominal aortic aneurysms. Transgene expression is similar in abdominal and thoracic endothelium. Levels of oxidative stress markers (oxidized proteins, lipid, and DNA) were similar in thoracic and abdominal aorta. Proteomic analyses established phenotypic switching in abdominal but not thoracic aorta, and also revealed activation of the oxidant-activated kinase ASK1 and of the MAP kinase cascade in abdominal but not thoracic aorta. Immunoblot analyses showed a marked decrease in JNK1 phosphorylation by phosphatase DUSP3 and an increase in vascular KLF4, leading to phenotypic switching of contractile to synthetic VSMCs.Conclusion:Chronic chemogenetic oxidative stress induces hypertension and abdominal aortic aneurysm formation caused by KLF4-dependent VSMC phenotypic switching.

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Novembre 2024

Abstract 4125939: Bayesian re-analysis of the STeroids to REduce Systemic inflammation after infant heart Surgery (STRESS) trial

Circulation, Volume 150, Issue Suppl_1, Page A4125939-A4125939, November 12, 2024. Background:Prophylactic steroids are often used to reduce the systemic inflammatory response to cardiopulmonary bypass in infants undergoing heart surgery. The STRESS trial found that the likelihood of a worse outcome did not differ between infants randomized to methylprednisolone vs placebo in a risk-adjusted primary analysis (adjusted odds ratio [OR], 0.86; 95% CI, 0.71 to 1.05; P=0.14). However, secondary unadjusted analyses showed possible benefits with methylprednisolone. We re-analyzed the STRESS trial using Bayesian analytics to assess probability of benefit with methylprednisolone.Methods:We used a covariate-adjusted proportional odds model using the original STRESS trial model covariates and primary outcome (a ranked composite of death, transplant, major complications and post-op length of stay). We assessed effect thresholds from OR 0.6 to 1.25 (OR 1 conveys harm). We assumed a neutral probability of benefit vs harm with weak prior belief (SD of the normal prior distribution = 0.425). In sensitivity analyses, we evaluated pessimistic (5%-30% prior likelihood of benefit), neutral and optimistic (70%-95% prior likelihood of benefit) prior beliefs, and controlled strength of prior belief as weak (SD = 0.425), moderate (SD = 0.215) and strong (SD = 0.135). We compared posterior distribution of the OR under these priors with the reference results under the vague prior distribution. Analyses consisted of 10 Markov Chain Monte Carlo simulations each consisting of 2000 iterations with a 1000 iteration burn-in to ensure proper posterior convergence.Results:In primary analysis, the posterior probability of benefit from methylprednisolone was 92% and the probability of harm was 8%. The mean absolute benefit was 12%. In sensitivity analyses, the probability of benefit was ≥ 79% for all informative priors except the most pessimistic (Table/Figure).Conclusion:In Bayesian re-analysis of the STRESS trial, probability of benefit with prophylactic methylprednisolone is high and harm is unlikely. Assessing probability of benefit or harm may be more informative than frequentist analytics relying on a p-value threshold. Another advantage is the ability to consider a range of prior evidence.

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Novembre 2024

Abstract 4143744: Cross-talk between oxidized LDL, oxidative stress and renin-angiotensin-aldosterone system: Impact on endothelial function and atherosclerosis

Circulation, Volume 150, Issue Suppl_1, Page A4143744-A4143744, November 12, 2024. Introduction/Background:Hypertension and hypercholesterolemia are important risk factors of endothelial dysfunction and atherosclerosis. Previous studies suggested a crosstalk between an activated renin-angiotensin-aldosterone system (RAAS), reactive oxygen species (ROS) and oxidized low-density lipoproteins (oxLDL) in atherosclerosis, but the underlying molecular mechanisms are not well understood.Research Question/Hypothesis:Can we identify novel signaling pathways controlling the molecular crosstalk of the RAAS with ROS and oxLDL in endothelial dysfunction and atherosclerosis?Methods/Approach:The impact of AT1R blockade on oxLDL-induced superoxide anion formation and endothelial dysfunction was studied in human umbilical artery endothelial cells and aortic rings of wild-type mice by chemiluminescence and Mulvany myograph. We cloned 5’-terminal deletions of the AT1R promoter and assessed the luciferase activity in human endothelial cells. Oct-1 binding to the human AT1R promoter region was studied by EMSA. Further assays included real-time PCR, confocal microscopy, Western blotting, G protein reporter assays, phospho-ERK1/2 antibodies and specific siRNAs. The data were validated in heart of obese C57BL/6 mice and cardiac and aortic tissue of AT1a/AT1bdouble knockout micein vivo.Results/Data:AT1R promoter activation studies upon Ang II- and oxLDL-stimulation in endothelial cells revealed that Ang II and oxLDL activate AT1R signaling through G protein Gα12/13, followed by activation of ERK1/2 MAP kinases, and transcription and translation of Oct-1, resulting in up-regulation of AT1R, LOX-1 and NOX2 expression, which could be antagonized by specific inhibitors at each step of the identified signaling cascade. AT1R blockade improved oxLDL-induced endothelial dysfunction in aortic rings of wild-type mice. Male C57BL/6 mice fed a high-fat diet exhibited upregulation of Oct-1 levels in cardiac tissues, compared to normal controls, while AT1a/AT1bdouble knockout mice demonstrated downregulation of Oct-1, AT1R, LOX-1, and NOX2 on mRNA and protein level in cardiac and aorta tissue, thus confirming the identified signaling cascadein vivo.Conclusions:Oct-1 is an essential transcription factor for Ang II- and oxLDL-induced upregulation of AT1R and LOX-1 expression in endothelium, thus identifying a novel molecular cross-talk of oxLDL with ROS signaling and the RAAS contributing to development of endothelial dysfunction and atherosclerosis.

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Novembre 2024