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

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 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.

Circulation, Volume 150, Issue Suppl_1, Page A4138348-A4138348, November 12, 2024. Methods and Results:We describe a comprehensive characterization of the AVICs nucleus landscape as determined by transmission electron microscopy (TEM) of samples obtained from CAVD patients. Turbulence led to nuclear envelope integrity lose in AVICs cultured in shear stress experiments, with three different fluid conditions [static (ST), laminar stress (LS), and oscillatory stress (OS)], indicated by Western blot and immunofluorescence (IF). Silencing lamin A/C (LMNA) through small interfering RNA (siRNA), accelerated nuclear envelope damage , as indicated by Western blot, qPCR, and immunofluorescence (IF). The formation of Z-DNA and its co-localization with Z-DNA binding protein (ZBP1) was observed due to the nuclear envelope damage by IF. Western blot, qPCR, IHC and IF confirmed Z-DNA-induced inflammation in AVICs through the ZBP1-RIPK3-NF-κB signaling pathway. ZBP1 and RIPK3 knockdown with siRNA markedly reduced the protein level of osteogenic markers alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX2), and bone morphogenetic protein 2 (BMP2) in VICs. In vivo, aortic valve disease was constructed by direct wire injury (DWI), and we showed that overexpression of LMNA by adeno-associated virus significantly decelerated the progression of aortic valve lesion induced by DWI in mice.Conclusion:Excessive mechanical stress can induce damage to the nuclear envelope of AVICs by causing cytoskeletal remodeling, initiating the formation of Z-DNA, and hastening the calcification process in AVICs and CAVD.

Circulation, Volume 150, Issue Suppl_1, Page A4119062-A4119062, November 12, 2024. Background:Vascular remodeling to match arterial diameter to tissue metabolic requirements commonly fails in ischemic disease. Endothelial cell (EC) sensing of elevated fluid shear stress (FSS) from blood flow induces vessel outward remodeling to restore physiological FSS, but mechanisms are poorly understood. The Smad1/5 pathway, which is maximally activated at physiological FSS and suppressed at higher flow, opposes activation of Akt, suggesting that inhibiting Smad1/5 may be required for outward remodeling.Methods:In vitro flow studies used ECs in a parallel plate flow chamber. In vivo mouse studies used a carotid-jugular fistula model to induce high flow outward remodeling in the carotid artery, and femoral artery ligation to examine recovery from ischemia and arteriogenesis in the hindlimb.Results:Suppression of Smad1/5 at high FSS is mediated KLF2-dependent induction of the BMP pathway inhibitor BMPER, which suppresses Smad1/5 and de-inhibits Akt. In a mouse arteriovenous fistula (AVF) model, high FSS induces arterial outward remodeling coincident with elevated BMPER expression and Smad1/5 inactivation. Endothelial BMPER deletion impaired blood flow recovery and vascular remodeling in the AVF and a hindlimb ischemia (HLI) model, with the latter reversed by BMP9/10 blocking antibodies (bAbs). In both STZ-induced type 1 and HFD-induced type 2 diabetic mice that show poor recovery from HLI, BMP9/10 bAbs improved outcomes.Conclusions:Suppression of Smad1/5 through a KLF2-BMPER pathway is required for high FSS-mediated outward remodeling. Mimicking this pathway with BMP9/10 antibodies improves vascular remodeling in diabetic mice, suggesting a potential new therapeutic approach for ischemic disease.

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 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 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 A4138517-A4138517, November 12, 2024. Background:Exercise stress echocardiography is routinely used for risk stratification and diagnosis of myocardial ischemia in low-to-intermediate risk patients with suspected coronary artery disease (CAD). Discrepancies between exercise electrocardiography (EKG) and echocardiography (ECHO) are common in clinical practice. Prior literature suggests that patients with discordant stress test results generally have worse outcomes, though the extent of epicardial atherosclerotic disease remains unclear. Coronary computed tomographic angiography (CTA) has gained a class I recommendation for the assessment of atherosclerotic burden per ACC/AHA chest pain guidelines. Using non-invasive fractional flow reserve (CT-FFR), the functional significance of lesions can also be assessed. This study investigates the incidence and burden of CAD in patients with discordant exercise echocardiography findings.Methods:Patients aged 18 or older who had exercise echocardiography followed by CTA from January 1, 2013, to January 31, 2023, were retrospectively enrolled in this study and categorized into two discordant result groups: EKG+/ECHO- or EKG-/ECHO+. Those who failed to achieve the target heart rate or had a paced rhythm/left bundle branch block on baseline EKG were excluded. CTA findings were classified as no CAD, non-obstructive CAD (

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.

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?

Circulation, Volume 150, Issue Suppl_1, Page A4146135-A4146135, November 12, 2024. Background:Epicardial adipose tissue (EAT) is increasingly recognized as a key factor in the development of atrial fibrillation (AF). In addition to direct myocardial infiltration by adipocytes affecting conduction properties, EAT may also promote an arrhythmogenic substrate through paracrine and endocrine effects. EAT was shown to preferentially generate oxidase-dependent reactive oxygen species (ROS) when compared to subcutaneous fat. While a role for myocardial ROS in the development of AF is well established, a separate role for EAT oxidative stress remains unexplored.Hypothesis:Oxidative stress in the EAT contributes to atrial electrical remodeling and development of AF.Aims:Determine the effect of EAT-restricted gene therapy with NOX2 shRNA on atrial electrical remodeling in the short-term canine atrial tachypacing (ATP) model of AF.Methods:A single-chamber pacemaker was inserted for the ATP model. Animals developed persistent AF after 4-6 weeks, after which the atria were harvested. Unpaced animals were used as controls. Expression of NOX2 in the EAT was assessed by qPCR. EAT oxidative stress was determined by IHC for 8-OHdG, a marker of DNA oxidative damage. A subset of animals underwent an open-chest gene injection procedure restricted to the EAT (with a plasmid expressing NOX2 shRNA or a scrambled sequence) prior to initiation of ATP for 9 days. A terminal EP study determined regional atrial ERP and AF inducibility.Results:NOX2 expression was significantly increased in the EAT of animals with ATP-induced AF when compared to unpaced controls (Panel A, p

Circulation, Volume 150, Issue Suppl_1, Page A4146032-A4146032, November 12, 2024. Background:Stress testing is a well-established non-invasive method commonly used in clinical practice for patients with angina. However, its benefit in diabetic patients after coronary intervention remains unclear. This systematic review aims to address this knowledge gap by evaluating the impact of routine stress testing in this specific patient population.Research Question:Does routine stress testing improve outcomes in diabetic patients with prior revascularization?Goals:We aimed to perform a systematic review and meta-analysis of studies that evaluated death, MACE and repeated revascularization episodes in diabetic patients who have prior coronary intervention.Methods:We searched PubMed, Embase and Cochrane databases for randomized controlled trials (RCT) and cohort studies evaluating diabetic patients who underwent cardiac revascularization and reporting the following outcomes: (1) Myocardial Infarction (MI) and Cardiovascular Death; (2) Ischemia; and (3) Repeat Revascularization. Statistical analysis was performed using Open Meta and heterogeneity was assessed with I2statistical.Results:We included 16924 patients from 16 studies, of which 15 were observational cohort studies and 1 was a RCT. All patients were diabetics and had a history of revascularization. Follow-up ranged from 1 to 5.2 years. The mean patient age was 60.8±9.5 years and 75% were male. MI and cardiovascular death was found in 9.8% (95% CI; range 6.8-12.8%; p

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 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.

Circulation, Volume 150, Issue Suppl_1, Page A4145622-A4145622, November 12, 2024. Introduction:Endothelial cells (ECs) can improve blood perfusion in diseased blood vessels associated with peripheral artery disease, but direct injection of therapeutic cells significantly decreases their survival and functionality for angiogenesis. To address these limitations, we employed a class of mechanically tunable protein hydrogels to enhance the survival and angiogenic behavior of human induced pluripotent stem cell-derived ECs (iPSC-ECs).Hypothesis:We hypothesize that the optimal stress relaxing mechanical property of hydrogels will modulate iPSC-EC survival and function in a mouse model of hindlimb ischemia.Materials&Methods:Engineered hydrogels, termed elastin-like protein (ELP)-polyethylene glycol (PEG), consists of two components of a hydrazine-modified elastin-like protein (ELP-HYD) and an aldehyde- or benzaldehyde-modified, polyethylene glycol (PEG-ALD or PEG-BZA), which interact with each other through hydrazone dynamic covalent chemistry bonds to form ELP-PEG hydrogels. By varying the use of PEG-ALD or PEG-BZA, we created hydrogels with the same stiffness but at either fast or slow stress relaxation rates. The hydrogels were assessed by dynamic oscillatory rheology. Afterwards, 106human iPSC-ECs were encapsulated within gels and injected into a mouse limb ischemia model to assess transplant cell viability and the ability to restore vascular perfusion to the ischemic limb.Results and Discussion:Although both hydrogels had a Young’s Modulus of 500 Pa, the stress relaxation rate of the PEG-BZA was 2.5h (slow), whereas that of PEG-ALD was within minutes (fast). When the iPSC-ECs were injected into the ischemic limb within either fast or slow-relaxing hydrogels or in saline, bioluminescence imaging of the luciferase-tagged iPSC-ECs showed higher cell survival within the fast-relaxing hydrogel over the course of the first 7 days. Blood perfusion recovery by laser Doppler similarly showed higher mean perfusion ratio when cells were delivered in the fast-relaxing hydrogel.Conclusions:ELP/PEG-ALD promotes iPSC-EC cell survival and perfusion recovery in the ischemic limb.

Circulation, Volume 150, Issue Suppl_1, Page A4138303-A4138303, November 12, 2024. Background:A higher stress hyperglycemic ratio (SHR) has been reported to be associated with adverse cardiac outcomes. However, the role of SHR in predicting clinical outcomes by comparing patients with and without diabetes mellitus is yet to be explored.Objective:To evaluate the prognostic value of the SHR for predicting major adverse cardiovascular (MACE) and all-cause mortality in ACS patients with and without diabetes mellitus.Methods:Per PRISMA guidelines, we comprehensively reviewed PubMed, Google Scholar, and SCOPUS for eligible studies reporting on SHR and its association with MACE (8 studies) and all-cause mortality (7 studies) in ACS patients. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a binary random-effects model, with results displayed as forest plots. Heterogeneity was assessed using I2 statistics, and a leave-one-out sensitivity analysis was performed. P