Model Of Chronic Heart Failure Research Articles

Sacubitril/valsartan ameliorates cardiac function and ventricular remodeling in CHF rats via the inhibition of the tryptophan/kynurenine metabolism and inflammation

Sacubitril/valsartan has been highly recognized as a treatment for Chronic heart failure (CHF). Its potential cardioprotective benefits and mechanisms, however, remain to be explored. Metabolomics can be used to identify the metabolic characteristics and related markers, as well as the influence of drugs, thereby opening up the new mechanism for sacubitril/valsartan therapy in CHF disease. In this study, the ligation of left anterior descending and exhaustive swimming were used to induce a rat model of CHF after myocardial infarction. The efficacy was appraised with echocardiography, serum NT-proBNP, and histopathologica. UPLC-Q/TOF–MS combined with multivariate statistical analysis approach were used to analyze the effect of sacubitril/valsartan on CHF rats. RT-qPCR and western blot were performed to investigate the tryptophan/kynurenine metabolism pathway. Accordingly, the basal cardiac function were increased, while the serum NT-proBNP and collagen volume fraction decreased in CHF rats with sacubitril/valsartan. Sacubitril/valsartan regulated the expression of kynurenine et.al 8 metabolomic biomarkers in CHF rats serum, and it contributed to the cardioprotective effects through tryptophan metabolism pathway. In addition, the mRNA and protein expression of the indoleamine 2,3-dioxygenase (IDO) in the myocardial tissue of CHF rats, were down-regulated by sacubitril/valsartan, which was the same with the IL-1β, IFN-γ, TNF-α, COX-2, and IL-6 mRNA expression, and IL-1β, IFN-γ, and TNF-α expression in serum. In conclusion, sacubitril/valsartan can ameliorate cardiac function and ventricular remodeling in CHF rats, at least in part through inhibition of tryptophan/kynurenine metabolism.

Exploring the Efficacy Enhancement Mechanism of Qixue Shuangbu prescription after TCM processing for treating chronic heart failure by regulating ERK/Bcl-2/Bax/Caspases-3 signaling pathway

Qixue Shuangbu prescription (QSP) has been used for the treatment of chronic heart failure (CHF) with remarkable curative effect. Processed QSP (PQSP) could significantly improve the treatment of CHF after traditional Chinese medicine (TCM) processing. This study elucidated the underlying efficacy enhancement mechanism of QSP after TCM processing for treating CHF in vitro and in vivo. The injury of rat cardiomyoblast H9c2 cells was induced by anoxia/reoxygenation to mimic CHF state in vitro. Sixty Sprague-Dawley rats were used to established CHF model by intraperitoneally injecting doxorubicin (the accumulative dose 15 mg/kg). Biochemical examinations were performed in serum and cellular supernatant, respectively. Cardiac functions and histopathological changes were evaluated in CHF model rats. The protein and mRNA levels of ERK1/2, Bcl-2, Bax and Caspase-3 were evaluated by Western blot and RT-PCR, respectively. All above results of low dose crude QSP-treated group (L-CQSP), high dose CQSP-treated group (H-CQSP), low dose PQSP-treated group (L-PQSP), high dose PQSP-treated group (H-PQSP) were compared to systematically explore correlations between TCM processing and the efficacy enhancement for treating CHF of PQSP. Compared with the model group, the L-CQSP group showed significant improvement in cardiac function at 8th weeks, while no significant improvement in cardiomyocyte apoptosis and fibrosis. Both H-CQSP, L-PQSP and H-PQSP exerted beneficial therapeutic effects in injured H9c2 cardiomyocytes and CHF model rats. L-PQSP and H-PQSP significantly increased cell viability and the activity of SOD, decreased the activities of LDH, MDA and NO, up-regulated the expression of ERK1/2 and Bcl-2, down-regulated the expression of Bax and Caspase-3 compared to the same dosage of CQSP. The efficacy enhancement mechanism of PQSP after TCM processing for treating CHF was directly related to the regulation of ERK/Bcl-2/Bax/Caspases-3 signaling pathway.

Preventive and Therapeutic Effects of Crocetin in Rats with Heart Failure.

Gardenia is both a food and medicine plant. It is widely used for cardiovascular protection, and its main bioactive ingredient is crocetin. This study aims to observe the therapeutic effects of crocetin on chronic heart failure in rats induced by various etiologies. It further compares the efficacy differences between preventative and treatment administration, varying dosages, and treatment durations, to provide improved guidance for medication in heart failure rats and determine which categories of chronic heart failure rats might benefit most from crocetin. Chronic heart failure models induced by abdominal aorta constriction, renal hypertension, and coronary artery ligation were constructed. By examining cardiac function, blood biochemistry, and histopathology, the study assessed the preventive and therapeutic effects of crocetin on load-induced and myocardial ischemia-induced heart failure. The results showed that in all three models, both treatment and preventative administration of crocetin significantly improved chronic heart failure in rats, especially in preventative administration. The results indicate crocetin may be beneficial for improving symptoms and functional capacity in rats with heart failure. Furthermore, long-term administration was more effective than short-term administration across all three rat models, with therapeutic onset observed over 6 weeks.

Effect of moxibustion combined with intraperitoneal injection of benazepril on endoplasmic reticulum stress-related protein phosphorylation in rats with chronic heart failure.

To observe the effect of moxibustion at "Xinshu"(BL15) and "Feishu"(BL13) combined with intraperitoneal injection of benazepril on cardiac function and phosphorylation of protein kinase R-like endoplasmic reticulum kinase (PERK) and eukaryotic initiation factor 2α (elF2α) proteins in myocardium of rats with chronic heart failure (CHF), so as to explore its potential mechanism underlying improvement of CHF. A total of 42 male SD rats were randomly assigned to blank control (n=10), CHF model (n=7), medication (benazepril, n=8), moxibustion (n=8) and moxibustion+benazepril (n=9) groups, after cardiac ultrasound model identification and elimination of the dead. The CHF model was established by intraperitoneal injection of doxorubicin hydrochloride (DOX), once every week for 6 weeks. Mild moxibustion was applied to bilateral BL15 and BL13 regions for 20 min, once daily for 3 weeks. The rats of the medication group and moxibustion+benazepril group (benazepril was given first, followed by moxibustion) received intraperitoneal injection of benazepril (0.86 mg/kg) solution once daily for 3 weeks . The cardiac ejection fraction (EF) and left ventricular fractional shortening (FS) were measured using echocardiography. Histopathological changes of the cardiac muscle tissue were observed under light microscope after hematoxylin-eosin (H.E.) staining. Serum contents of B-type brain natriuretic peptide (BNP) and angiotensin Ⅱ (AngⅡ) were measured by enzyme-linked immunosorbent assay (ELISA). The expressions of phospho-PERK (p-PERK) and phospho-elF2α (p-elF2α) in the myocardium were detected by Western blot. Compared with the blank control group, the EF and FS of the left cardiac ventricle were significantly decreased (P<0.01), while the contents of serum BNP and AngⅡ, and expression levels of p-PERK and p-eIF2α significantly increased in the model group (P<0.01). In comparison with the model group, both the decreased EF and FS and the increased BNP and AngⅡ contents as well as p-PERK and p-elF2α expression levels were reversed by moxibustion, medication and moxibustion+benazepril (P<0.01). The effects of moxibustion+benazepril were markedly superior to those of simple moxibustion and simple medication in raising the levels of EF and FS rate and in down-regulating the contents of BNP, Ang Ⅱ, levels of p-PERK and p-elF2α (P<0.01, P<0.05). Outcomes of H.E. staining showed irregular arrangement of cardiomyocytes, cell swelling, vacuole and inflammatory infiltration in the model group, which was relatively milder in the 3 treatment groups. The effects of moxibustion+benazepril were superior to those of moxibustion or benazepril. Moxibustion combined with Benazepril can improve the cardiac function in CHF rats, which may be related to its functions in down-regulating the expression levels of myocardial p-PERK and p-elF2α to inhibit endoplasmic reticulum stress response.

Neutrophils are indispensable for adverse cardiac remodeling in heart failure

Persistent immune activation contributes significantly to left ventricular (LV) dysfunction and adverse remodeling in heart failure (HF). In contrast to their well-known essential role in acute myocardial infarction (MI) as first responders that clear dead cells and facilitate subsequent reparative macrophage polarization, the role of neutrophils in the pathobiology of chronic ischemic HF is poorly defined. To determine the importance of neutrophils in the progression of ischemic cardiomyopathy, we measured their production, levels, and activation in a mouse model of chronic HF 8 weeks after permanent coronary artery ligation and large MI. In HF mice, neutrophils were more abundant both locally in failing myocardium (more in the border zone) and systemically in the blood, spleen, and bone marrow, together with increased BM granulopoiesis. There were heightened stimuli for neutrophil recruitment and trafficking in HF, with increased myocardial expression of the neutrophil chemoattract chemokines CXCL1 and CXCL5, and increased neutrophil chemotactic factors in the circulation. HF neutrophil NETotic activity was increased in vitro with coordinate increases in circulating neutrophil extracellular traps (NETs) in vivo. Neutrophil depletion with either antibody-based or genetic approaches abrogated the progression of LV remodeling and fibrosis at both intermediate and late stages of HF. Moreover, analogous to murine HF, the plasma milieu in human acute decompensated HF strongly promoted neutrophil trafficking. Collectively, these results support a key tissue-injurious role for neutrophils and their associated cytotoxic products in ischemic cardiomyopathy and suggest that neutrophils are potential targets for therapeutic immunomodulation in this disease.

Canagliflozin combined with aerobic exercise protects against chronic heart failure in rats

To determine the efficacy and potential protective mechanism of canagliflozin combined with aerobic exercise in treating chronic heart failure (CHF). Isoproterenol was injected into rats to create CHF models. The rats were then subsequently divided into saline, canagliflozin (3mg/kg/d), aerobic exercise training, and canagliflozin combined with aerobic exercise training. Compared to the CHF group, the canagliflozin combined with the aerobic exercise group had superior ventricular remodeling and cardiac function. In rats treated with canagliflozin combined with aerobic exercise, the expression of cytochrome P450 (CYP) 4A3, CYP4A8, COL1A1, COL3A1, and FN1 was reduced, while the expression of CYP26B1, ALDH1A2, and CYP1A1 increased significantly. Additionally, canagliflozin combined with aerobic exercise decreased the phosphorylation of AKT and ERK1/2. Canagliflozin combined with aerobic exercise has a positive effect on the development of CHF via the regulation of retinol metabolism and the AKT/ERK signaling pathway.

Correlation of the Left Ventricular Systolic Dysfunction and Ventricular Depolarization in a Post-Infarction Model of Chronic Heart Failure.

The body surface potential mapping of the heart during the period of ventricular depolarization and the inotropic function of the ventricles were studied in rats under conditions of a translational model of post-infarction chronic heart failure developed by us. We revealed a statistically significant (p<0.001) correlation between the left-ventricular ejection fraction and the values of the maximum positive and negative extrema of the cardioelectric field on the body surface of rats with post-infarction chronic heart failure caused by anterior transmural myocardial infarction. The calculated linear regression equations have high predictive efficiency, which makes it possible to use the amplitude characteristics of the heart cardioelectric field as a marker of the development of chronic heart failure.

Lung-to-Heart Nano-in-Micro Peptide Promotes Cardiac Recovery in a Pig Model of Chronic Heart Failure

BackgroundThe lack of disease-modifying drugs is one of the major unmet needs in patients with heart failure (HF). Peptides are highly selective molecules with the potential to act directly on cardiomyocytes. However, a strategy for effective delivery of therapeutics to the heart is lacking. ObjectivesIn this study, the authors sought to assess tolerability and efficacy of an inhalable lung-to-heart nano-in-micro technology (LungToHeartNIM) for cardiac-specific targeting of a mimetic peptide (MP), a first-in-class for modulating impaired L-type calcium channel (LTCC) trafficking, in a clinically relevant porcine model of HF. MethodsHeart failure with reduced ejection fraction (HFrEF) was induced in Göttingen minipigs by means of tachypacing over 6 weeks. In a setting of overt HFrEF (left ventricular ejection fraction [LVEF] 30% ± 8%), animals were randomized and treatment was started after 4 weeks of tachypacing. HFrEF animals inhaled either a dry powder composed of mannitol-based microparticles embedding biocompatible MP-loaded calcium phosphate nanoparticles (dpCaP-MP) or the LungToHeartNIM only (dpCaP without MP). Efficacy was evaluated with the use of echocardiography, invasive hemodynamics, and biomarker assessment. ResultsDpCaP-MP inhalation restored systolic function, as shown by an absolute LVEF increase over the treatment period of 17% ± 6%, while reversing cardiac remodeling and reducing pulmonary congestion. The effect was recapitulated ex vivo in cardiac myofibrils from treated HF animals. The treatment was well tolerated, and no adverse events occurred. ConclusionsThe overall tolerability of LungToHeartNIM along with the beneficial effects of the LTCC modulator point toward a game-changing treatment for HFrEF patients, also demonstrating the effective delivery of a therapeutic peptide to the diseased heart.

Shenfu Injection improves chronic heart failure by regulating pyroptosis based on NLRP3/caspase-1 pathway

This study investigated the mechanisms and targets of Shenfu Injection in the intervention in chronic heart failure(CHF) through the NOD-like receptor thermal protein domain associated protein 3(NLRP3)/caspase-1 signaling pathway. A CHF model was induced in rats by subcutaneous injection of isoproterenol. Model rats were randomly divided into a model group, a Shenfu Injection group, and a MCC950(NLRP3 inhibitor) group, and a blank group was also set up as a control. After 15 days of treatment, echocardiography was performed to measure cardiac function parameters [left ventricular ejection fraction(LVEF) and left ventricular fractional shortening(LVFS)]. Enzyme-linked immunosorbent assay(ELISA) was used to measure serum levels of N-terminal pro-brain natriuretic peptide(NT-proBNP), interleukin(IL)-1β, and IL-18. Hematoxylin-eosin(HE) and Masson staining were used to observe morphological changes in myocardial tissues, and Western blot was used to measure the expression levels of NLRP3/caspase-1 pathway-related proteins [NLRP3, caspase-1, apoptosis-associated speck-like protein containing a CARD(ASC), gasdermin D(GSDMD), IL-1β, and IL-18]. The study found that isoproterenol-induced CHF in rats resulted in decreased cardiac function, worsened myocardial fibrosis, increased expression levels of NLRP3, ASC, caspase-1, GSDMD-N, IL-1β, and IL-18 in myocardial tissues, elevated serum inflammatory factors, and induced myocardial cell pyroptosis. Following Shenfu Injection intervention, the Shenfu Injection group showed significantly improved LVEF and LVFS, a significant decrease in NT-proBNP, a marked downregulation of NLRP3, ASC, caspase-1, GSDMD-N, IL-1β, and IL-18 protein expression levels, reduced serum inflammatory factors IL-1β and IL-18 expression in CHF rats, and a decrease in the rate of TUNEL-positive cells. Shenfu Injection can significantly improve cardiac function in CHF, inhibit myocardial fibrosis, and alleviate the progression of myocardial cell pyroptosis through the inhibition of the NLRP3/caspase-1 pathway.

Biologically derived epicardial patch induces macrophage mediated pathophysiologic repair in chronically infarcted swine hearts

There are nearly 65 million people with chronic heart failure (CHF) globally, with no treatment directed at the pathologic cause of the disease, the loss of functioning cardiomyocytes. We have an allogeneic cardiac patch comprised of cardiomyocytes and human fibroblasts on a bioresorbable matrix. This patch increases blood flow to the damaged heart and improves left ventricular (LV) function in an immune competent rat model of ischemic CHF. After 6 months of treatment in an immune competent Yucatan mini swine ischemic CHF model, this patch restores LV contractility without constrictive physiology, partially reversing maladaptive LV and right ventricular remodeling, increases exercise tolerance, without inducing any cardiac arrhythmias or a change in myocardial oxygen consumption. Digital spatial profiling in mice with patch placement 3 weeks after a myocardial infarction shows that the patch induces a CD45pos immune cell response that results in an infiltration of dendritic cells and macrophages with high expression of macrophages polarization to the anti-inflammatory reparative M2 phenotype. Leveraging the host native immune system allows for the potential use of immunomodulatory therapies for treatment of chronic inflammatory diseases not limited to ischemic CHF.

A novel technology for heart failure that utilizes the respiratory effort to shift fluids from the lung and alleviate cardiac workloads; feasibility study in sheep

Abstract Introduction Hemodynamic congestion is governed by inflow from RV and drainage through LV. However, ventricle functions are affected by the intrathoracic/pleural pressure: Negative pleural pressure (PPL) increases RV outflow while decreasing LV outflow, and vice versa at high PPL. Cardiac decompensation is associated with an increase in the respiratory effort (the peak-to-peak changes in PPL). We suggest to utilize this respiratory effort to shift fluid out of the lung and alleviate hemodynamic congestion. It is done by pacing the heart when PPL is high and the LV stroke volume is larger than the RV stroke volume. Purpose To test the feasibility of the novel technology in sheep. To verify that it is possible to modify the distribution of the heart beat within the respiratory cycle (slightly modify the rhythm according to the PPL) with insignificant effect on mean heart rate. Methods The utility was validated in sheep (N=9), under spontaneous breathing before and after induction of acute infarction by balloon inflation in the mid-LAD artery. The device senses the intracardiac electrical activity and respiratory effort and paces the right atrium when the PPL is high. The R-R interval of the paced beats was shorter than the sinus R-R interval by less than 10%. The effects of PPL and device pacing on LV and RV stroke-volumes were derived from simultaneous measurements of RV and LV pressure-volume loops, utilizing two impedance catheters (CD-Leycom) within both ventricles. Results The respiratory effort had significant effects on RV and LV outputs before and after infarction. The stroke volumes of the two ventricles were in antiphase! At low PPL the RV output increased while the LV decreased by about 10%, and the opposite occurred at high PPL. The pacing increased cardiac beating probability at high PPL. Sequential pacing for one minute increased the systolic pressure by 5 mmHg while decreasing the pulmonary artery pressure. Based on the pressure-volume loops, each paced breath cycle increased the LV outflow by 1.14 ml and decreased RV outflow by 0.36ml, yielding a shift of 1.5 ml from the lung. Interestingly, it was associated with a decrease in the sinus rate, which further decreased cardiac beating at low PPL and may represent a decrease in sympathetic tone. Conclusions Pacing only 1% of the ∼20,000 daily breath-cycles can shift 300 ml from the lung per day! The technology is agnostic of the heart-failure etiology. Preclinical studies in a model of chronic heart failure are required to further validate the novel approach.

Long-acting CRF2 peptide agonist improves cardiac function in a rat heart failure model

Abstract Introduction Corticotropin-releasing factor receptor type 2 (CRF2) is a G protein-coupled receptor largely expressed in the cardiorenal system. Upon CRF2 activation, endogenous ligands such as urocortin-2 (UCN-2) or urocortin-3 (UCN-3) have been reported to increase cardiac function, decrease vascular resistance and improve natriuresis and diuresis in heart failure (HF) patients and in various experimental heart failure settings. However UCN-2 or -3 suffer from a very short half-life which markedly limit further clinical investigations in HF patients. For this purpose, a very long acting CRF2 peptide agonist has been developed. Objectives The aim of this study is to determine the acute effect on cardiac hemodynamic of a long acting CRF2 peptide agonist, COR-1167, in a rat model of chronic heart failure. Methods In 10-week-old Wistar rats, a total occlusion of the left anterior descending coronary artery was performed to induce myocardial infarction. Twelve weeks after myocardial infarction, rats had developed heart failure and received COR-1167 at the dose of 0.3 µg/kg or 1 µg/kg, or placebo, administered SC. Left ventricular dimensions and function were then assessed by echocardiography and left ventricular pressure-volume analysis. Results Three months after left coronary artery ligation rats displayed the classical features of heart failure as illustrated by an increase in left ventricular diastolic diameter and reduced ejection fraction, and decreases in LV end-systolic pressure, dP/dtmax and LV end-systolic pressure volume relationship. Major LV diastolic dysfunction developed, as shown by the increases in LV end-diastolic pressure, and LV end-diastolic pressure volume relationship and the decrease in dP/dtmin. Echocardiography and left ventricular pressure-volume analysis showed that COR-1167 at 0.3 and 1 µg/kg SC improved in a dose-dependent manner cardiac contractility and relaxation as assessed by LVESPVR and LVEDPVR, respectively. In addition, stroke volume and cardiac output were significantly ameliorated by COR-1167 at 1.0 µg/kg SC, with no change in heart rate. Conclusion Single acute administration of COR-1167 improved cardiac function in a rat model of heart failure with reduced ejection fraction. Altogether these results confirm that CRF2 agonism is an attractive therapeutic target for the treatment of heart failure.

Mitophagy-dependent cardioprotection of resistance training on heart failure.

Resistance exercise is an indispensable mode of exercise rehabilitation for heart failure. Here we elucidate the cardiac effects of resistance training alone or combined with different aerobic trainings on heart failure and explore the critical regulation of mitophagy. The chronic heart failure model was constructed by transverse aortic constriction surgery, followed by 8 wk of resistance training (RT), moderate-intensity continuous training combined with resistance training (MRT), and high-intensity interval training combined with resistance training (HRT), and subsequently analyzed the changes of maximum load, cardiac structure and function, and myocardial mitophagic activity. The role and signaling of mitophagy in exercise protection of heart failure were investigated by knockdown of Hif1α and Parkin genes in primary neonatal cardiomyocytes. RT and especially MRT improved maximum load (P < 0.0001), myocardial morphology and fibrosis (P < 0.0001), reduced left ventricular diameter and enhanced left ventricular systolic function (P < 0.01), and enhanced myocardial mitophagic activity and HIF1α expression (P < 0.05) in heart failure mice. However, HRT had no obvious protective effect on ventricular diameter and function or mitophagy. The abilities of exercise stimulation to regulate reactive oxygen species, adenosine triphosphate, and brain natriuretic peptide were impaired after knockdown of Hif1α and Parkin genes inhibited mitophagy in failing cardiomyocytes (P < 0.05). Different exercise modalities provide discrepant cardiovascular effects on heart failure, and MRT exhibits optimal protection. The HIF1α-Parkin-mitophagy pathway is involved in the protection and regulation of exercise on heart failure.NEW & NOTEWORTHY Impaired myocardial mitophagy is implicated in the pathogenesis of heart failure. Resistance training alone or combined with different aerobic trainings provide discrepant cardiovascular effects on heart failure, and the cardioprotective function depends on HIF1α-Parkin-mitophagy pathway.

Abstract 15205: miR-132 Inhibition Improves Myocardial Strain in a Large Animal Model of Chronic Adverse Remodeling

Background: MicroRNAs (miRNAs) are transcriptional regulators and essential drivers of heart failure (HF). The miR-132 is necessary and sufficient to progress adverse cardiac remodeling. The strong effects are exhibited by, amongst others, cardiomyocyte hypertrophy and calcium signaling impairment. Treatments directly targeting the roots of the disease are scarce, but miR-132 inhibition by CDR132L, a rationally designed synthetic oligonucleotide, significantly improves cardiac dysfunction in HF early after myocardial infarction (MI). Rational: The aim of the current study was to gain further data on myocardial function and efficacy of CDR132L by analyzing left ventricular (LV) and atrial (LA) wall motion by serial cardiac magnetic resonance (cMRI) strain imaging in a clinically relevant large animal (pig) model of chronic HF. Methods and Results: Mangalica pigs (n=15) were randomized 1-month post-MI, initiated by left anterior descending artery occlusion followed by reperfusion as a chronic model of post-MI HF. Animals received CDR132L over 5 months by monthly intravenous treatments with 5 mg/kg. LV and LA strain parameters were deteriorated after MI over time but significantly ameliorated by CDR132L treatment, compared to placebo. Strain parameters showed significant correlations with pharmacodynamic measures such as left-ventricular ejection fraction, NT-proBNP and cardiac interstitial fibrosis in remodeling hearts 6 months post-MI. Conclusions: LV and LA motion and contractility were improved by repeated dosing of CDR132L with monthly frequency in a large animal model of chronic post-MI HF. The results highlight the translational value and usability of MRI-based cardiac strain imaging in HF drug development and support further clinical development of CDR132L.

Abstract 16452: Targeting Notch3 Pathway and Using Extracellular Vesicles From Induced Pluripotent Stem Cell-Derived Cardiomyocytes is Effective in Porcine Chronic Myocardial Injury Model

Introduction: Heart failure is the leading cause of hospital admission in the modern U.S. We previously demonstrated that exosomes (Ex) from iPSC-derived cardiomyocytes (iCMs) significantly restored murine peri-infarct region. We found that miR20/92/363 (CORE miRNA) activated iCM proliferation and myocardial restoration by repressing the Notch3 pathway. However, the optimal pre-clinical method to target the Notch3 pathway through Ex, miRNA, and siRNA remains to be assessed. Hypothesis: Exosomes are the most effective biologic for chronic porcine heart failure model. Methods: iPSCs were generated from four heart failure patients (Pt 1-4) and differentiated into iCMs. Ex were isolated from the iCM culture media and used to treat iCMs subjected to hypoxia-injury. The in vitro findings were then confirmed in vivo in Yorkshire pigs subjected to myocardial ischemia-reperfusion injury for one hour via balloon occlusion of the left descending artery. One month later, chronic heart failure model was developed, and percutaneous catheter system (Biocardia, Inc) delivered 10 11 Ex, 4200 μg of CORE miRNA, or 4200 μg of siNotch3 into porcine peri-infarct region. MRI and mRNA seq analyzed the porcine myocardium. Results: Viability of hypoxia-injured iCMs treated by siNotch3 (132.50% viability ± 23.54% SD)*, CORE miRNA (127.79% ± 10.06%)*, Pt 1 Ex (74.88% ± 3.11%)*, Pt 2 Ex (72.90% ± 4.50%)*, Pt 3 Ex (79.11% ± 7.23%)*, and Pt 4 Ex (77.81% ± 3.31%)* all significantly improved iCM viability compared to non-treated hypoxia-injured iCMs (26.09% ± 10.75%, *p&lt;0.05). In porcine chronic heart failure model (n=4 - 6/treatment group), the mean absolute change in LVEF of PBS (control), siNotch3, CORE miRNA, and Pt 1 Ex treatments were -3.55 ± 3.27, 1.19 ± 3.17*, 2.34 ± 1.53*, and 3.53 ± 3.59*, respectively (*p&lt;0.05). mRNA seq, gene ontology, and KEGG analysis of porcine myocardium suggested that myocardial repair occurred through the TGFβ pathway and cell cycle re-entry of cardiomyocytes. Conclusion: siRNA, miRNA, and exosomes are all effective methods to repair the porcine myocardium after chronic myocardial injury. Exosome showed the highest functional restoration. Determination of mechanism and optimal biologic and dose are underway.

Abstract 18729: cBIN1 Gene Therapy Improves Recovery of Peri-Infarction Muscle in a Canine Model of Chronic Ischemic Heart Failure

BACKGROUND: Heart failure (HF) due to ischemic dilated cardiomyopathy (IDCM) is a major cause of morbidity and mortality. In failing hearts, loss of T-tubule microdomains is central to impaired calcium transients and loss of cardiac function. Cardiac bridging integrator 1 (cBIN1), a membrane scaffolding protein that organizes T-tubule microdomains, is transcriptionally reduced in failing hearts. Hypothesis: cBIN1 gene therapy will improve cardiac function in ischemic cardiomyopathy. AIM: Evaluate the effectiveness of catheter-based delivery of cBIN1 gene therapy in preserving bipolar voltage (an assay of muscle health) and LVEF in a canine model of IDCM. Methods: Nine healthy adult mongrel dogs (30±3 kg) underwent LAD ligation, developing IDCM and HFrEF (LVEF &lt; 40% and NT-proBNP &gt;900 pmol/L) over 3-4 months. Animals received a single treatment at 20 sites by intramyocardial injection of either AAV9-GFP (control, n=3) or AAV9-cBIN1 (n=6) using a MyoStar catheter-mediated subendocardial injection. Low voltage LV regions were quantified as percent of total endocardial area with bipolar voltage &lt;1.5 mV on the day of the treatment (pre-therapy) and the terminal study (5-10 weeks post-therapy). Results: In control-treated dogs, low voltage areas did not change significantly (19.5±3.4 vs. 28.7±9.8%, p=0.143, Figure A ), whereas in the cBIN1-treated cohort, the low voltage areas surrounding infarction zones decreased significantly (18.9±10.9 vs. 13.4±9.1%, p=0.038, Figure B ). Control therapy was associated with an additional 9.2% loss LV myocardium, whereas cBIN1 therapy caused a 6.5% recovery of myocardium (p=0.024, Figure C ). Post-therapy week 5, LVEF decreased in control animals (36±2 vs. 29±3%, p&lt;0.001) yet improved in the cBIN1-treated animals (37±2 vs. 41±3%, P=0.003). CONCLUSION: Intramyocardial injection of cBIN1 gene therapy can halt and reverse expansion of peri-infarction low voltage areas and improve LVEF in a preclinical IDCM model of chronic HF.

Abstract 18810: Mitochondria-Rich Extracellular Vesicles From Stem Cell-Derived Cardiomyocytes Restore Bioenergetic Metabolism of Ischemic Myocardium in a Porcine Chronic Heart Failure Model

Introduction: The disruption of mitochondrial energy metabolism underlies the pathophysiology of ischemic heart failure. We previously demonstrated that intramyocardial injection of mitochondria-rich extracellular vesicles (M-EVs) derived from iPSC-derived cardiomyocytes (iCMs) transfers mitochondria and non-mitochondrial biologics into recipient cardiomyocytes. This process stimulates mitochondrial biogenesis and enhances functional capacities in murine and porcine acute myocardial infarction (MI) models. However, the therapeutic potential and underlying mechanism in chronic heart failure models remain to be assessed. Method: M-EVs were isolated from the conditioned medium of human iCMs using differential centrifugation. A total of 11 Yorkshire pigs underwent myocardial ischemia for one hour via balloon occlusion of the left anterior descending artery (Week-0). At week-4, 1.0 x 10 11 M-EVs or PBS control were administered transendocardially to the peri-infarct region (PIR) using a percutaneous catheter delivery system (Biocardia, Inc, CA). Cardiac functions and scar size were analyzed by cardiac MRI with gadolinium contrast at week-4 (pre-injection) and -8 (post-injection). Myocardial tissue samples were collected from the PIR and remote non-ischemic areas at week-8. Proteomic analysis and single-nucleus RNA sequencing were performed to investigate comprehensive protein and gene expression profiles of the myocardium. Results: Left ventricular (LV) ejection fractions were significantly decreased at Week-4 (32.7±5.4%). M-EV treatment significantly improved absolute LVEF from week-4 to -8 in the treatment vs. non-treatment groups, +3.15% vs. -4.99%, respectively, (p&lt;0.0001). No significant difference was observed in the scar size. Multiomic analysis of proteomes and single-nucleus transcriptomes suggested restoration of dysregulated cardiometabolic protein profile and mitochondrial energy metabolism in the myocardium. Conclusion: M-EV-mediated transfer of mitochondria and enriched proteins augmented LV dysfunction in the pig chronic MI model. M-EV therapy may represent a novel biologic approach that directly targets cardiac metabolism by restoring mitochondrial function and cellular bioenergetics.

Protective effect of Shenfu Injection on regulation of autophagy in rats with chronic heart failure based on PI3K/Akt/mTOR pathway

This study aimed to investigate the mechanism and target sites of Shenfu Injection in the intervention of chronic heart fai-lure based on the PI3K/Akt/mTOR autophagy signaling pathway. The chronic heart failure model was induced in rats by subcutaneous injection of isoproterenol. The model rats were randomly divided into model group, Shenfu Injection group, and 3-methyladenine autophagy inhibitor(3-MA) group. A normal group was also set up. After 15 days of administration, cardiac function indexes of the rats were detected by echocardiography. The serum N-terminal pro-B-type natriuretic peptide(NT-proBNP) levels were measured using the ELISA. HE and Masson staining was performed to observe the morphological changes in myocardial tissues, and electron microscopy was used to observe the autophagosomes in myocardial tissues. Western blot was conducted to measure the changes in autophagy-related proteins(LC3 Ⅱ/Ⅰ and p62), PI3K, Akt, mTOR, and phosphorylation levels. The results showed that compared with normal group, model group in rats led to reduced cardiac function, significant activation of cardiac autophagy, increased fibrotic lesions in myocardial tissues, structural disorder of the myocardium, increased autophagosomes, and cytoplasmic vacuolization. Compared with model group, Shenfu Injection group in rats led to cardiac function significantly improved, myocardial fibrosis decreased, and the number of autophagosomes and cytoplasmic vacuolization decreased. The phosphorylation levels of PI3K, Akt, and mTOR were significantly increased(P&lt;0.01). In the 3-MA group, autophagy was inhibited through the activation of the PI3K/Akt/mTOR signaling pathway, resulting in improved cardiac function, reduced myocardial fibrosis, and no significant cytoplasmic vacuolization. The findings suggest that Shenfu Injection can activate the PI3K/Akt/mTOR signaling pathway and inhibit autophagy, thereby improving cardiac function.

Ambulatory 7-day mechanical circulatory support in sheep model of pulmonary hypertension and right heart failure

Right heart failure is the major cause of death in pulmonary hypertension. Lung transplantation is the only long-term treatment option for patients who fail medical therapy. Due to the scarcity of donor lungs, there is a critical need to develop durable mechanical support for the failing right heart. A major design goal for durable support is to reduce the size and complexity of devices to facilitate ambulation. Toward this end, we sought to deploy wearable mechanical support technology in a sheep disease model of chronic right heart failure. In 6 sheep with chronic right heart failure, a mechanical support system consisting of an extracorporeal blood pump coupled with a gas exchange unit was attached in a right atrium-to-left atrium configuration for up to 7days. Circuit performance, hematologic parameters, and animal hemodynamics were analyzed. Six subjects underwent the chronic disease model for 56 to 71days. Three of the subjects survived to the 7-day end-point for circulatory support. The circuit provided 2.8 (0.5) liter/min of flow compared to the native pulmonary blood flow of 3.5 (1.1) liter/min. The animals maintained physiologically balanced blood gas profile with a sweep flow of 1.2 (1.0) liter/min. Two animals freely ambulated while wearing the circuit. Our novel mechanical support system provided physiologic support for a large animal model of pulmonary hypertension with right heart failure. The small footprint of the circuit and the low sweep requirement demonstrate the feasibility of this technology to enable mobile ambulatory applications.

Influence of experimental heart failure therapy with different generations of β-adrenergic blockers on Cardiac Electrical Activity (ECG) and Autonomic Regulation of Heart Rhythm (ARHR)

Abstract: In the complex treatment of chronic heart failure (CHF) β-adrenoblockers (carvedilol, nebivolol, bisoprolol, metoprolol) are used, which due to their pharmacological properties increase the survival rate of patients, improve cardio- and haemodynamic parameters, metabolism. However, modern realities in medicine require creation of new more effective and safe β-adrenoblockers. In this regard, the potential drug Hypertirl is of interest. The aim was to evaluate the cardioprotective effect of 1-(b-phenylethyl)-4-amino-1,2,4-triazolium bromide (Hypertril) on cardiac electrical activity and autonomic regulation of heart rhythm in a model of CHF in comparison with β-adrenoblockers of different generations (Nebivolol, Carvedilol, Bisoprolol, Metoprolol). Materials and methods: Chronic heart failure was induced by 14-day administration of doxorubicin in a cumulative dose of 15 mg/kg to white mongrel rats weighing 190–220g (total 85). The investigated drugs were administered after doxorubicin course for 30 days: Hypertril at an experimentally substantiated dose of 3.5 mg/kg, Metoprolol succinate 15 mg/kg, Nebivolol 10 mg/kg, Carvedilol 50 mg/kg, Bisoprolol 10 mg/kg. At the end of drug administration under thiopental anaesthesia (40 mg/kg), electrocardiogram (ECG) and autonomic regulation of heart rhythm (ARHR) were analysed using a computer analyser CardioCom-2000plus (KAI-Medica, Ukraine). The results of the study were calculated using a standard statistical package “STATISTICA for Windows 6.0” (StatSoftInc., №AXXR712D833214FAN5), “SPSS 16.0” and “Microsoft Office Excell 2003”. Results and discussion: Hypertril administration resulted in a negative chronotropic effect, normalisation of atrial (P) and ventricular (R) spike amplitude, ST segment inversion below isoline, increased amplitude of ventricular myocardial repolarisation T. Myocardial repolarisation spike were observed, as well as normalised the duration of atrial (P) and ventricular depolarisation phase (QRS complex) to the intact value and restored the duration of electrical diastole (TR interval). Hypertril reduced systolic and diastolic myocardial dysfunction in animals with CHF. Hypertril restored autonomic mechanisms of heart rhythm regulation and balanced activity of sympathetic and parasympathetic parts of autonomic nervous system in the control of cardiac function. Conclusion: The obtained results demonstrated the undoubted advantage of the new original molecule (Hypertril) over basic β-adrenoblockers (Metoprolol, Nebivolol, Carvedilol and Bisoprolol) and experimentally justify further in-depth study to create on its basis a drug for the treatment of CHF.