Risultati per: Lo stress può essere causa di infarto ed ictus

Circulation, Volume 150, Issue Suppl_1, Page A4145955-A4145955, November 12, 2024. Introduction:Cardiovascular problems are the primary cause of morbidity and death in people with diabetes mellitus.The whole nature of diabetic cardiomyopathy(DCM) is yet unknown.In order to investigate the pathogenesis of DCM and find possible treatment targets,animal models have proven invaluable.It has been common practice to create experimental models of type 2 diabetes(T2DM) using streptozotocin (STZ).Finerenone(F) is a selective mineralocorticoid receptor antagonist and reduces cardiovascular and adverse renal outcomes in diabetes.Exenatide(E) has been approved by the FDA to improve glycemic control in T2DM.Aim:The aim of this study is to investigate the possible cardiorenal protective effects of potential heart failure and chronic kidney injury associated with T2DM and to assess the potential therapeutic roles of Finerenone and Exenatide.To understand the interactions on cardiorenal outcomes of heart failure and diabetes and to effectively manage these two conditions.Methodology:Wistarmale rats with streptozotocin-induced T2DM were used.Five different groups were established as 1)Control,2)STZ,3)STZ+F,4)STZ+E,5)STZ+F+E groups.During the 21-day experiment, blood glucose concentrations were measured in all animal experimental groups.The kidney, heart tissues, and blood serum were collected. Serum urea and creatinine were exanimated.Total antioxidant status(TAS) and total oxidant status(TOS) were examined from blood serum,kidney,heart tissues by spectrophotometric assays. Kidney, heart tissues and blood IL-6, IL-1β, TNF-α gene expressions were examined by qPCR. Cardiac troponin T(cTnT) and troponin I(cTnI) gene expressions were examined by qPCR.p-STAT3 and p-NRF2 protein expressions in heart tissue were assessed by western blotting.Results:Serum urea and creatinine were significantly lower in STZ+E+F group than control group. TAS were significantly higher in STZ+E+F group than control group in serum,heart and kidney tissues.TOS, IL-1β, IL-6, and TNF-α gene expressions were lower in STZ+E+F groups than control group significantly in serum, heart and kidney tissues.cTnT and cTnI gene expressions and p-STAT3 and p-NRF2 protein expressions were lower in STZ+E+F groups than control group significantly in heart tissues.Conclusion:This study demonstrates the potential beneficial effects of Finerenone and Exenatide on cardiorenal complications in T2DM. Evaluation of these drugs in treatment strategies and further clinical trials are recommended.

Circulation, Volume 150, Issue Suppl_1, Page A4141357-A4141357, November 12, 2024. Background:Cardiac allograft vasculopathy (CAV) is a rapidly progressive form of coronary atherosclerosis limiting long-term survival after heart transplantation.Objectives:We evaluated the diagnostic and prognostic yield of quantitative stress cardiovascular magnetic resonance (CMR) perfusion for CAV detection in heart transplant recipients.Methods:Patients who received orthotopic heart transplants and underwent stress CMR for CAV assessment were included in the study and followed up for almost 2 years (median 1.8; IQR 0.9,2.7). The diagnostic accuracy of qualitative and quantitative stress CMR was assessed by calculating sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), using invasive or CT coronary angiography as the reference for CAV detection. The area under the curve (AUC) was compared for qualitative and quantitative stress CMR. Adjusted hazard ratios for major adverse cardiac events (MACE), including death and unplanned cardiac hospitalizations were derived in all patients. The global myocardial perfusion reserve index (MPRi) was obtained by normalization to the rate-pressure product.Results:In a cohort of 60 patients, n=18 (30%) had significant CAV (grade 2 or 3), and n=11 (18.3%) experienced MACE. At the Youden index threshold of 2.1, the myocardial perfusion reserve index (MPRi) demonstrated a sensitivity of 85.7%, a specificity of 70.3%, a PPV of 52.2%, and an NPV of 92.9%. The MPRi was significantly more accurate than visual assessment (p < 0.001) in identifying underlying CAV (Figure 1) and it was an independent predictor of MACE (HR:0.26;95%CI:0.07,0.93; log-rank p=0.022; Figure 2), while the visual presence of inducible myocardial perfusion defect did not (HR:2.23;95%CI:0.57,8.66; p=0.2).Conclusions:In patients with previous heart transplantation, quantitative stress CMR perfusion has incremental diagnostic and prognostic value over qualitative stress CMR for the non-invasive detection of CAV.

Circulation, Volume 150, Issue Suppl_1, Page A4146754-A4146754, November 12, 2024. Background:Dobutamine stress echocardiography (DSE) is a frequently used tool in cardiovascular (CV) risk assessment of liver transplantation (LT) candidates. Its prognostic value compared to traditional cardiac risk stratification remains unclear.Research Question:How does the prognostic value of pre-transplant DSE in LT candidates compare to the revised cardiac risk index (RCRI)?Aim:Compare DSE’s prognostic value to RCRI in LT patients and analyze post-transplant CV outcomes.Methods:This single-center study included adult patients undergoing pre-transplant DSE as part of LT evaluation from 2008-2021. DSE were categorized as positive, negative, or inadequate. Primary outcomes were post-operative ischemic cardiac events and mortality, with secondary outcome of transplant delays from inadequate DSE. Mann-Whitney U and Fischer’s exact tests compared variables; logistic regression assessed RCRI and DSE for 30-day mortality and cardiac events.Results:Of 981 LT candidates, 644 (66%) had pre-transplant DSE with minimum 2-year follow-up. Average age was 57 ± 7 years, with 33% women. Four and eleven patients experienced cardiac events and mortality 1 (p-value 0.50), 0.51 for DSE (p-value 0.82), and 0.52 for RCRI >1 and DSE combined (p-value 0.80) in predicting 30-day mortality and cardiac events.Conclusion:Our study demonstrates limited prognostic value of DSE above RCRI score alone for predicting post-transplant mortality. Inadequate DSE was frequent and extended LT wait times. Further research is necessary to define clinically relevant subgroups and refine CV risk assessment in LT candidates.

Circulation, Volume 150, Issue Suppl_1, Page A4145229-A4145229, November 12, 2024. Background:Stress-induced cardiomyopathy (CM) is a form of acute transient left ventricular dysfunction triggered by underlying physiological stress which often leads to increased morbidity and mortality. Coronavirus disease 2019 (COVID-19) is thought to cause stress-induced CM due to overwhelming systemic inflammation. There is paucity of data regarding the impact of COVID-19 on in-hospital outcomes of patients with stress-induced CM. The purpose of this study is to investigate in-hospital outcomes, including mortality and cardiogenic shock, of patients with concomitant COVID-19 and stress-induced CM.Methods:We queried the 2020 USA National Inpatient Sample (NIS) Database in conducting this retrospective cohort study. We identified hospitalized adult patients ≥ 18 years old with stress-induced CM and concomitant COVID-19 using ICD-10 CM codes. We used a survey multivariable logistic and linear regression analysis to calculate adjusted odds ratios (aORs) for outcomes of interest. A p value of

Circulation, Volume 150, Issue Suppl_1, Page A4145148-A4145148, November 12, 2024. Introduction:Junctophilin-2 (JPH2) plays essential roles in multiple cardiac processes including calcium handling, t-tubule structure, and gene regulation. We recently showed JPH2 also has a mitochondrial role as it binds the mitochondrial protein mitofusin-2 (MFN2) and modulates mitochondrial metabolic function. However, the impacts of JPH2 disease-causing variants on MFN2 binding and subsequent cellular responses to metabolic stressors are unknown.Methods:Disease-associated variants in the MFN2 binding domain of JPH2 were engineered and recombinantly expressed in E. coli cells. Purified proteins were then subjected to pulldown experiments to assess MFN2 protein binding. Alphafold3 modeled how MFN2 and JPH2 and JPH2 E169K mutants interacted in the presence or absence of fatty acids. Wildtype JPH2 or JPH2 E169K expression was directed by a doxycycline inducible promoter after being cloned into the AAVS1 locus in JPH2 knockout iPSC-cardiomyocytes. In vitro metabolic stress was induced by incubating iPSC-CM with 150 μM oleate, 150 μM palmitate, and 500 μM carnitine overnight. Super resolution confocal microscopy visualized mitochondria integrity, nuclei shape and size, and lipid droplet accumulation and morphology.Results:In pulldown experiments, the JPH2 E169K mutation disrupted MFN2 binding. Alphafold3-based modeling showed JPH2 E169K disrupted the interaction between the two proteins when modeled with or without lipids (A-D). Control, wild type JPH2, and JPH2 E169K iPSC-CM displayed divergent responses to in vitro metabolic stress. JPH2 E169K cells exhibited pathological mitochondrial network changes characterized by a lower mitochondrial footprint and less network branches (E-G). In addition, the JPH2 E169K iPSC-CM accumulated significantly more lipid droplets in the cytoplasm and the nucleus, and the JPH2 E169K lipid droplets were significantly larger than the other cell types (H-K). Finally, the accumulation of lipid droplets impacted nuclear morphology as the JPH2 E169K cells had nuclear hypertrophy and nuclei were more ellipse-shaped (L-N).Conclusion:The JPH2 E169K variant disrupts MFN2 binding, which results in heightened metabolic stress characterized by lipid droplet accumulation and mitochondrial and nuclear morphological changes. These results implicate a new pathophysiological mechanism for how the JPH2 E169K mutation causes cardiac dysfunction.

Circulation, Volume 150, Issue Suppl_1, Page A4147568-A4147568, November 12, 2024. Introduction:Cardiovascular disease (CVD) and cancer are among the leading causes of morbidity and mortality worldwide. Increasing evidence suggests that sociodemographic factors such as race, ethnicity, income, education, and stress levels significantly influence the prevalence and outcomes of these diseases. TheAll of UsResearch Program provides a unique opportunity to explore these disparities across a diverse U.S. population. This study aims to examine how sociodemographic disparities are associated with stress, CVD, and cancer outcomes. We hypothesize that higher perceived stress levels, lower income, lower education levels, and minority race/ethnicity groups are associated with higher incidences of CVD and cancer.Methods:Data from 55,505All of UsResearch program participants were analyzed. Key variables included age, race, ethnicity, education, household income, perceived stress level, and history of CVD and cancer. Descriptive statistics were used to summarize participant demographics. Multivariate logistic regression models were employed to examine the associations between sociodemographic factors and the outcomes of interest (CVD and cancer).Results:Older participants had a higher prevalence of both CVD (mean age: 60.8 vs. 50.5, p < 0.001) and cancer (mean age: 63.6 vs. 51.7, p < 0.001). Black/African Americans had a higher incidence of CVD (21.3% vs. 78.7%, p < 0.001), while Whites had a higher prevalence of cancer (5.3% vs. 94.7%, p < 0.001). Lower income and higher stress levels were also associated with higher CVD incidence (

Circulation, Volume 150, Issue Suppl_1, Page A4145104-A4145104, November 12, 2024. Background:The optimal timing for intervention for pulmonary and right ventricular outflow tract stenosis in adult congenital heart disease (ACHD) remains uncertain. While stress echocardiography is an established modality to improve risk stratification in stenotic left-sided lesions, its utility in right-sided valve disease in the ACHD population has not been studied. We assessed if stress echocardiographic assessment of right ventricular (RV) function during cardiopulmonary exercise testing (CPET) can facilitate risk stratification in the ACHD population.Objectives:The purpose of this study was to determine the relationship between RV augmentation on stress echocardiogram during CPET and morbidity in ACHD patients with sub-pulmonary right ventricles and right-sided stenotic lesions.Methods:A retrospective cohort study of ACHD patients with sub-pulmonary right ventricles who underwent CPET with stress echocardiogram was performed. The primary outcome was defined as having at least one of the following: 1) cardiac related hospitalization, 2) new documented arrhythmia, or 3) new or worsening heart failure. RV augmentation on stress echo was verified by concordance with a second observer.Results:The study included 87 patients, 41 (47%) with repaired tetralogy of Fallot, 9 (10.3%) with RV-PA conduits, and 9 (10.3%) with pulmonary stenosis. On baseline transthoracic echocardiogram, median peak pulmonary valve gradient was 38.7 mmHg (Q1 17.9 , Q3 49.0) and 30% of patients had RV dysfunction. On stress imaging, 13 (14.9%) did not demonstrate RV augmentation. Those without RV augmentation had a lower percent predicted peak Vo2 (61.4% vs 75.4%, p=0.007). Eleven (12.6%) met the primary outcome. Lack of RV augmentation was strongly associated with the primary outcome (OR 4.25, CI 1.04 –17.46, p = 0.04). This association remained true in patients with baseline peak PV gradients less than 50mmHg (OR 8.7, CI 1.68 – 46.79, p = 0.009) and was more pronounced in patients with tetralogy of Fallot (OR 33.99, CI 3.29 – 829, p = 0.007).Conclusions:Lack of RV augmentation on stress echo during CPET is associated with increased morbidity in ACHD patients with right-sided stenotic lesions. These results suggest that stress echocardiography at the time of CPET should be considered in this population.

Circulation, Volume 150, Issue Suppl_1, Page A4141710-A4141710, November 12, 2024. Background:Stress perfusion CMR has excellent diagnostic and prognostic values in assessing chest pain syndromes. AI-guided methods may overcome complex scanning and increase clinical adaptation of stress CMR.Aim:To assess the benefits of AI-guided stress perfusion CMR.Methods:Consecutive patients with stable chest pain underwent stress CMR using either a standard scanning method (SOC) or an AI-assist (AIA) machine learning protocol to automate scan planning, plane prescription, sequence tuning, and image reconstruction. Scan duration, the ratio of scan preparation time over the entire scan duration, and scan quality using a 5-point scale were compared between AIA and SOC. Cox regression models were constructed to associate evidence of ischemia on stress CMR, by either scanning method, with composite endpoints including cardiovascular death, non-fatal MI, unstable angina hospitalization, and late CABG. A second composite endpoint included the performance of additional cardiac imaging tests (stress imaging and CCTA) and invasive coronary procedures after CMR.Results:Among 594 patients (62.8 ± 14 years), 29% underwent stress CMR with AIA. 26% had stress-perfusion ischemia, and 39% had LGE present. AIA stress CMR had lower scan duration (median 44.0 [IQR 40-47] vs. 52.5 min [IQR 46-60]; p

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.

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

Circulation, Volume 150, Issue Suppl_1, Page A4143092-A4143092, November 12, 2024. Background:Very high level, lifelong aerobic exercise results in lower ventricular stiffness and left ventricular wall stress (LVWS) LVWS is an important predictor of future heart failure risk. To what degree LVWS changes with various doses of lifelong aerobic exercise is unknown.Objective:The purpose of this study was to determine the impact of lifelong exercise on LVWS.Methods:Seniors (n = 58) who consistently participated in lifelong patterns of exercise training were recruited and categorized into 3 groups: “sedentary” (

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.

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

Circulation, Volume 150, Issue Suppl_1, Page A4141840-A4141840, November 12, 2024. BACKGROUND:Pulmonary arterial hypertension (PAH) is characterized by obliteration of distal pulmonary arteries (PA) in association with endothelial cell (EC) dysfunction, leading to smooth muscle proliferation. SOX17 is a transcription factor (TF) expressed in arterial EC that is critical in vascular development. Deleterious variants causing reduced expression ofSOX17are linked to PAH, particularly in congenital heart defects (CHD) that cause increased PA flow and high shear stress (HSS).HYPOTHESIS:SOX17 deficiency is additive to HSS in compromising PAEC homeostasis and in promoting severe PAH.METHODS:SOX17was reduced ( >70%) by siRNA in primary human PAEC cultured in chamber slides in the IBIDI perfusion system. Computational modeling of distal PA indicated pathological HSS of 100 dyn/cm2in CHD with PAH whereas physiological laminar shear stress (LSS) is 15 dyn/cm2. EC were preconditioned under LSS for 24h, followed by HSS or LSS for 24h.RESULTS:SOX17 expression was increased under LSS versus static condition, as were known SOX17 target genes (e.g.,GJA5,GJA4,CGNL1,JAG1, andCTNNB1). SOX17siRNA and HSS similarly reduced SOX17 target genes and when combiningSOX17siRNA with HSS they were further decreased owing to an interaction between SOX17 and ERG, a TF reduced by HSS. Indeed, SOX17 and ERG motifs marked most enhancer and promoter H3K27acetyl marks that were reduced under HSS. We then carried out RNAseq of PAEC to find genes co-regulated by SOX17 and ERG (reduced by siRNA for either TF under LSS), decreased under HSS and more-so with HSS +SOX17siRNA. Those downregulated included SOX17 targets (e.g.,CGNL1andGJA5) and others not previously described, with links to BMPR2 signaling,YAP1(inducer of BMP ligands and suppressor of NF-kB),SETBP1(inducer of BMPR2 co-receptorBMPR1b),andTMEM100andSULT1B1important in NOTCH signaling and EC specification. We also found novel extracellular matrix target genes, e.g., elastin (ELN,top DEG),HMCN1,TMTC1and chromatin remodeler (TOX). Among genes upregulated, wereNAMPT, FAS, LYN, HPSErelated to NF-kB activation and/or inflammation.CONCLUSION:HSS plus SOX17 deficiency profoundly compromises EC homeostatic genes, among which are those affecting BMPR2 and NOTCH pathways, ELN fiber assembly, and those promoting inflammation. This can explain whySOX17mutations are associated with severe PAH in HSS-related congenital heart defects.

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.

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