Model Of Heart Failure Research Articles

CardiLect: A combined cross‐species lectin histochemistry protocol for the automated analysis of cardiac remodelling

AbstractBackgroundCardiac remodelling, a crucial aspect of heart failure, is commonly investigated in preclinical models by quantifying cardiomyocyte cross‐sectional area (CSA) and microvascular density (MVD) via histological methods, such as immunohistochemistry. To achieve this, optimized protocols are needed, and the species specificity is dependent on the antibody used. Lectin histochemistry offers several advantages compared to antibody‐based immunohistochemistry, including as cost‐effectiveness and cross‐species applicability. Direct comparisons between the two methods are lacking from the literature.Methods and resultsIn this study, we compared antibody‐ and lectin‐based methods for the histological assessment of cardiomyocyte CSA (with the use of anti‐laminin and wheat germ agglutinin [WGA]) and microvascular density (utilizing anti‐CD31 and isolectin B4 [ILB4]) using different embedding and antigen/carbohydrate retrieval techniques. Here, we describe a detailed, easy‐to‐use combined lectin histochemistry protocol (WGA and ILB4, ‘CardiLect’ protocol) for the histological assessment of cardiac remodelling. The lectin‐based approach has been evaluated on a cross‐species basis, and its efficacy has been demonstrated in zebrafish, rodents, large animals and human samples. We provide an ImageJ script (‘CardiLect Analyser’) for automated image analysis, validated in a preclinical heart failure model by correlating histological parameters with echocardiographic findings. CSA showed a significant positive correlation with left ventricular (LV) mass (P = 0.0098, rS = 0.7545) and significant negative correlation with markers of systolic function, such as ejection fraction (EF) (P = 0.0402, rS = −0.6364). Microvascular density showed significant negative correlation with LV mass (P = 0.0055, rS = −0.7622) and significant positive correlation with EF (P = 0.0106, rS = 0.7203).ConclusionsThe described combined lectin histochemistry protocol with the provided ImageJ script is an easy‐to‐use, cost‐effective, cross‐species approach for the histological assessment of cardiac remodelling.

Abstract 4135617: Large Scale Proteomics Identifies Circulating Biomarkers Relating Atrial Fibrillation to Heart Failure: the Atherosclerosis Risk in Communities Study

Introduction: There is a bidirectional relationship between atrial fibrillation (AF) and heart failure (HF) risk. Data regarding shared and unique pathways underlying each are limited. Aims: Identify plasma proteins associated with both incident AF and HF and determine the extent to which associations with one outcome are conditional on interval occurrence of the other outcome. Methods: Among participants in the community-based Atherosclerosis Risk in Communities study free of HF and AF at study visit 5 (2011-2013), we measured 4,955 plasma proteins (SomaScan aptamer-affinity assay). We performed parallel analyses of individual protein associations with incident HF and AF using multivariable Cox regression adjusted for demographic and clinical covariates at Bonferroni significance. We then repeated the analysis for each outcome in models censoring participants with interval occurrence of the other outcome (i.e. incident AF censoring for interval HF, and vice versa). We tested associations of AF-related proteins with echocardiographic and Zio patch measures at Visit 5. Results: Among 4,118 participants included, mean age was 75±5 years, 60% were female, and 18% reported Black race. We identified 83 proteins associated with incident HF (n=355 incident events at 7 [IQR 6-8] year follow-up) and 24 with incident AF (n=517 incident events at 8 [7-9] years), of which 10 were associated with both. In models of incident HF censoring for interval AF, 63 (76%) proteins remained significantly associated with HF. In contrast, in the analysis of incident AF censoring for interval HF, only 4 (17%) proteins remained associated with AF, of which 3 were also associated with HF risk (Figure). These 4 AF-related proteins were associated with measures of LV diastolic function (LA volume, E/e’. average), LV mass index, LA function (LA reservoir, LA contraction), and supraventricular ectopy density (all p<0.05). Conclusion: Nearly half of proteins reflecting AF risk also associate with HF, greater than 80% of AF-associated proteins are HF-dependent, and even those that are not correlate with measures of LV remodeling and dysfunction. These findings suggest that AF-related mechanisms among older adults are part of a wider HF syndrome.

Abstract 4138674: Long-acting CRF2 receptor agonist, COR-1389, improves cardiopulmonary function in the rat model of Sugen plus hypoxia-induced pulmonary hypertension and right heart failure

Introduction: Urocortin-2 (UCN-2), a peptide which is part of the corticotropin-releasing factor (CRF) family, functions as an autocrine and paracrine factor, exerting its effects on cardiac and pulmonary function through agonism of CRF2 receptors. Although acute administration of UCN-2 has shown promise by improving heart and lung function in conditions like heart failure (HF) and pulmonary hypertension (PH), its limited stability impedes its chronic therapeutic use. Hypothesis: In this study, we explored the efficacy of COR-1389, a potent, selective and long-acting CRF2 agonist peptide, in the Sugen 5416 (VEGFR2 inhibitor, Su) combined with hypoxia (Hx) rat model of PH and right heart failure (RHF). Methods: To this aim, male adult Sprague Dawley rats were divided into three groups: Control rats (normoxia) were compared with rats injected subcutaneously with 20 mg/kg Sugen 5416 and exposed to chronic hypoxia for 3 weeks, followed by 2 weeks of normoxia. At 5 weeks, control rats and one SuHx group received subcutaneously vehicle (control and SuHx), while the third group received COR-1389 at a dose of 100 μg/kg every 4 days subcutaneously for 3 weeks (SuHx + COR-1389). At 8 weeks, cardiac and pulmonary hemodynamic functions of the three groups were evaluated using echocardiography and right heart catheterization, and heart and lung tissue were evaluated by histology and immunohistochemistry. Results: Compared to controls (n=10), SuHx exhibited increased mean pulmonary arterial pressure (mPAP), right ventricle (RV) hypertrophy (Fulton Index/body weight), muscularization of distal pulmonary arteries, RV fibrosis and cardiomyocyte hypertrophy, alongside reduced RV systolic function (Tricuspid Annular Plane Systolic Excursion, TAPSE) and cardiac output (CO). Conversely, compared to the SuHx + vehicle group (n=11), curative treatment with COR-1389 for 3 weeks in SuHx rats (n=13) led to enhanced RV systolic function (TAPSE) and CO, together with reductions in mPAP, RV hypertrophy, muscularization of pulmonary arteries, RV fibrosis and cardiomyocyte hypertrophy. Systolic blood pressure remained unchanged across all groups. Conclusion: These findings indicate that COR-1389 ameliorates the deteriorating cardiopulmonary parameters observed in the SuHx model and represents a promising approach for the treatment of PH and RHF.

Abstract 4122257: Inhibition of Neutrophil Extracellular Traps Prevents Heart Failure by Preserving Mitochondrial Function of Cardiomyocytes in Mice

Background: We have previously demonstrated that neutrophil extracellular traps (NETs) in myocardial tissue are associated with cardiac dysfunction and adverse outcomes in patients with heart failure with reduced ejection fraction. Here, we aimed to elucidate the underlying mechanisms and to clarify whether inhibiting NETs could rescue the cardiac phenotype using ex vivo and in vivo models. Methods and Results: Given that peptidyl arginine deiminase 4 (PAD4) is essential for the formation of NETs, PAD4 knockout mice were used for this study. First, we assessed the mitochondrial function of cardiomyocytes by conducting real-time measurements of the oxygen consumption rate in ex vivo . Extracellular flux analysis revealed that NETs-containing conditioned medium from wild-type neutrophils or purified NET components led to impaired mitochondrial oxygen consumption of adult mouse cardiomyocytes, while these effects were abolished when PAD4 in neutrophils was genetically ablated (Figure 1). In a murine model of pressure overload-induced heart failure, transverse aortic constriction (TAC) operation was performed on wild-type and PAD4 knockout mice. Immunohistological analysis demonstrated that TAC induced the formation of NETs in the myocardium, with the greatest number of NETs occurring at 1 day, persisting into the failing stage at 4 weeks in wild-type mice, while PAD4-deficient hearts displayed no presence of NETs in the heart tissue (Figure 2). Four weeks after TAC, left ventricular ejection fraction was reduced in wild-type mice, whereas PAD4 knockout mice displayed preserved left ventricular ejection fraction (Figure 2). Finally, we investigated the bioenergetics of cardiomyocytes isolated from PAD4 knockout mice after TAC. Maximal mitochondrial oxygen consumption rate in cardiomyocytes isolated from TAC-operated PAD4 knockout mice was significantly higher than in those from TAC-operated wild-type mice (Figure 3). Conclusion: Our data suggest that NETs directly derived impairment of mitochondrial function in cardiomyocytes. Inhibiting NETs represents a potential therapeutic approach for heart failure, preventing mitochondrial dysfunction of cardiomyocytes.

Abstract 4138716: A novel Urocortin-2 analog COR-1167 corrects cardiac and renal dysfunction on top of Empagliflozin in a rat model of acute decompensated heart failure

Introduction: Urocortin-2 (UCN-2) is a peptide belonging to the corticotropin-releasing factor family that has cardiovascular, renal, metabolic and anti-inflammatory actions and improves cardiac function in human heart failure (HF) and cardiorenal dysfunction in chronic HF models. However, UCN-2 has a short half-life and intravenous delivery limits its therapeutic use. COR-1167 was discovered as a stable UCN-2 analog with qd pharmacological effects when injected subcutaneously. Hypothesis: Whether COR-1167 exerts chronic cardiorenal protection in Acute Decompensated HF (ADHF) is unknown, and in particular on background of SGLT2 inhibition, therefore both treatments were tested in a rat model of ADHF. Methods: Rats had coronary artery ligation to induce MI and a reduced ejection fraction phenotype. Three months later, rats were treated with vehicle or Empagliflozin (Empa) at 10 mg/kg/day PO. One month after starting Empa, two acute decompensation events were induced by administrating NaCl solution (1.8 g/kg, PO) on Day 0 and Day 14. Empa treated ADHF rats received vehicle or COR-1167 (3 µg/kg/day) by SC injections starting at 12 hours after the first decompensation and all treatments continued for 14 days. The groups were ADHF, ADHF + Empa and ADHF + Empa + COR-1167 (n=7-10/group). Left ventricular (LV) hemodynamics (cardiac catheters), cardiac output (echocardiography) and LV tissue perfusion (magnetic resonance imaging), cardiac mitochondrial coupling and ATP production (Seahorse) were measured 1 day after the second decompensation, while urine volume (uVol) and urine Na + excretion (uNa + ) collected from metabolic cages were analyzed 7 days after the first decompensation. Results: Compared to ADHF control rats, Empa treatment had no effect on systolic blood pressure (SBP), cardiac output (CO), LV end systolic pressure volume relationship (LVESPVR), LV end diastolic pressure volume relationship (LVEDPR), mitochondrial coupling and ATP production, but it increased myocardial perfusion, uVol and uNa + excretion. Compared to ADHF + Empa rats, COR-1167 treatment increased SBP, CO, LVESPVR, myocardial perfusion, mitochondrial coupling and ATP production, uVol, uNa + , while decreasing LVEDPVR. Conclusion: In the setting of ADHF, significant cardiorenal benefits and decongestion occurred when COR-1167 was administered on top of an SGLT2 inhibitor.

Calycosin alleviates ferroptosis and attenuates doxorubicin-induced myocardial injury via the Nrf2/SLC7A11/GPX4 signaling pathway

BackgroundHeart failure is primarily characterized by damage to the structure and function of the heart. Ferroptosis represents a form of programmed cell death, and studies indicate that it constitutes one of the primary mechanisms underlying cardiomyocyte death in heart failure. Calycosin, a natural compound derived from astragalus, exhibits various pharmacological properties, including anti-ferroptosis, antioxidant effects, and cardiovascular protection. Nonetheless, the specific role of Calycosin in the treatment of ferroptosis in heart failure remains poorly understood.ObjectiveThis study aims to elucidate the regulatory effect of Calycosin on ferroptosis and its influence on the treatment mechanisms of heart failure through in vivo and in vitro experiments.MethodsA rat model of heart failure was induced using doxorubicin, and the cardiac function was evaluated through cardiac ultrasound examination and NT-Pro BNP detection. Myocardial injury was assessed using H&E staining and Masson staining. The extent of mitochondrial damage was evaluated through transmission electron microscopy. Concurrently, the level of ferroptosis was analyzed by measuring ferroptosis markers, including MDA, ferrous ions, the GSH/GSSG ratio, and GPX4 activity. Subsequently, the molecular mechanism by which Calycosin exerts its therapeutic effects in heart failure was investigated through immunofluorescence and Western blotting. Finally, H9c2 cardiomyocytes were treated with doxorubicin to simulate myocardial injury, and the mechanism by which Calycosin mediates its effects in the treatment of heart failure was further verified through Nrf2 gene silencing.ResultsCalycosin significantly improves cardiac function in rats, reduces serum NT-Pro BNP levels, and alleviates myocardial cell damage. Additionally, it significantly decreases the levels of ferroptosis in myocardial tissue, as confirmed through transmission electron microscopy and the assessment of ferroptosis markers, including MDA, ferrous ions, GSH, and GPX4 activity. At the molecular level, Calycosin exerts its effects by activating the Nrf2/SLC7A11/GPX4 signaling pathway, evidenced by the upregulation of Nrf2, SLC7A11, GPX4, GSS, and GCL protein expression. This process substantially enhances the antioxidant capacity of rat myocardial tissue and effectively suppresses ferroptosis in myocardial cells. The results obtained from both in vivo and in vitro experiments are consistent. Notably, when Nrf2 is silenced, the protective effect of Calycosin on the myocardium is markedly diminished.ConclusionCalycosin effectively treats doxorubicin-induced cardiac injury, and its therapeutic effect is likely closely associated with the activation of the Nrf2/SLC7A11/GPX4 signaling pathway and the inhibition of ferroptosis in myocardial cells. Consequently, Calycosin, as a promising compound against doxorubicin-induced cardiotoxicity, warrants further investigation.

Abstract 4143270: PREDICTIVE MODELS AID PHYSICIAN PROGNOSTICATION: A SECONDARY ANALYSIS EVALUATING INTEGRATED MODEL AND PHYSICIAN PROGNOSTIC ESTIMATES IN PATIENTS WITH HEART FAILURE WITH REDUCED EJECTION FRACTION

Background: In recent studies from a multicenter Canadian cohort of outpatients with heart failure (HF), we found that model predictions were significantly more accurate than HF cardiologists. In this study, trying to mimic practice, we evaluated the additional predictive value and clinical impact of model predictions to refine physician estimated risk of 1-year mortality by combining model and physician estimates. Methods: We included consented consecutive HF outpatients (LVEF <40%) followed at 11 HF clinics in Canada. HF cardiologists estimated patient 1-year mortality using their clinical judgment. We calculated model predicted mortality using the Seattle HF Model (SHFM). We followed patients for at least a year to record mortality (or urgent heart transplant or ventricular assist device implant as mortality-equivalent events). Using random forest survival model and cross-validation, we compared the performance SHFM and the HF cardiologist alone, and the integrated HF cardiologist and the SHFM predictions by evaluating model discrimination (c-statistic), calibration (observed vs predicted event rate), risk reclassification and clinical net benefit analyses. Results: Among 1,643 HF patients, 1-year event rate was 9% (95%CI 8%-11%). The SHFM had the adequate discrimination (c-statistic 0.76) and excellent calibration while cardiologists showed adequate discrimination (c-statistic 0.75) and poor calibration with significant risk overestimation ( Figure 1 ). When the SHFM estimates were added physician predictions, discrimination significantly improved (0.82, 95%CI 0.78-0.86) with excellent calibration. By risk reclassification analysis, among patients with events, HF cardiologist better reclassified 44% than the SHFM or the integrated model. Among patients without event, however, HF cardiologists worse risk-classified 52% in comparison to SHFM and 71% to the integrated model. By net clinical benefit analysis ( Figure 2 ), when the decision to treat involves patients with 1-year mortality of >5%, SHFM predictions would lead to higher benefit than guiding care by physician judgement. Integrating model and HF cardiologist predictions led to minimally increased benefit in comparison to SHFM alone. Conclusions: Integrating prediction from the SHFM to physician judgment or using the SHFM alone showed superior accuracy than HF cardiologist predictions, proving that model-informed care may provide more accurate prognostic information to tailor clinical decision making.

Impaired oxytocin signalling in the central amygdala in rats with chronic heart failure

AbstractHeart failure (HF) patients suffer from cognitive decline and mood impairments, but the molecular signals and brain circuits underlying these effects remain elusive. The hypothalamic neuropeptide oxytocin (OT) is critically involved in regulating mood, and OTergic signalling in the central amygdala (CeA) is a key mechanism that controls emotional responses including anxiety‐like behaviours. Still, whether an altered OTergic signalling contributes to mood disorders in HF remains unknown. To address this, we used an ischaemic rat HF model, along with a highly multidisciplinary approach, to mechanistically study multiple levels of the hypothalamus‐to‐CeA OTergic circuit in male rats with HF. We aimed to test the hypothesis that sustained activation of the OT system following an infarct leads to depletion of OT content in this pathway, with subsequent changes in OT receptor expression and blunted modulation of local GABAergic circuits. We found that most of OTergic innervation of the CeA originated from the supraoptic nucleus (SON). While no differences in the numbers of SON→CeA OTergic neurons was observed between sham and HF rats, we observed a blunted content and release of OT from axonal terminals within the CeA. Moreover, we report downregulation of neuronal and astrocytic OT receptors, and impaired OTR‐driven GABAergic synaptic activity within the CeA microcircuit of HF rats. We provide the first evidence that male HF rats display perturbations in the hypothalamus‐to‐amygdala OTergic circuit, laying the foundation for future translational studies targeting either the OT system or GABAergic amygdalar microcircuit to ameliorate mood impairments in rats or patients with chronic HF. imageKey points Heart failure patients suffer from cognitive decline, depression and mood impairments, but the underlying mechanisms remain elusive. Acting within the central amygdala, the neuropeptide oxytocin regulates emotional responses, including anxiety‐like behaviours. However, whether changes in oxytocin signalling occurs during heart failure is unknown. In this study, we used an ischaemic rat heart failure model to mechanistically study multiple levels of the hypothalamus‐to‐amygdala oxytocinergic circuit in this disease. We report an overall blunted oxytocinergic signalling pathway in rats with heart failure, including blunted content and release of oxytocin from axonal terminals, downregulation of neuronal and astrocytic oxytocin receptors, and impaired oxytocin‐driven GABAergic synaptic activity within the central amygdala microcircuit of HF rats. These studies shed light on mechanisms that contribute to mood disorders in cardiovascular disease states and help to identify potential molecular targets for their improved treatment.

Abstract 4134975: ROS-Traf6-Yap Promotes the Development of Cardiac Hypertrophy

Introduction: Heart failure (HF) is caused by structural and functional abnormalities of the heart and is associated with high morbidity and mortality. Pathological myocardial hypertrophy accounts for a significant portion heart failure. The Yap protein was found to be responsive to mechanotransduction signals and can limit organ size by inducing cell cycle arrest during development. In the heart, pathological activation of Yap has been shown to drive cardiac hypertrophy, but regenerative activation of Yap can promote myocardial cell-cycle re-entry. However, how Yap is pathologically activated in the beating cardiomyocyte remains elusive. Hypothesis: ROS-Traf6 promotes the development of cardiac hypertrophy by activating Yap in a non-canonical fashion. Methods: Traf6 protein levels in heart failure patients biopsies as well as in various murine failing hearts were examined by immunofluorescence. Molecular interrogation of ROS-Traf6-Yap signaling axis was performed in primary neonatal rat cardiomyocytes (NRCM) and human induced pluripotent stem cell derived cardiomyocytes. Yap protein stability and activation by Traf6 was examined by immunoprecipitation, CHX induction, and point mutation. Myocardial specific Traf6 knockout and Yap mutant animals were used to evaluate Traf6-Yap signaling in vivo . Results: We found that Traf6 expression was significantly elevated in multiple heart failure models. Using the transverse aortic constriction (TAC)-induced cardiac hypertrophy model, pressure overload increased ROS levels which activated Traf6. Traf6 overexpression induced myocardial hypertrophy while knockdown blocked myocardial hypertrophy in Ang II treated NRCMs. Mechanistically, Traf6 binds to and ubiquitinates Yap-K234 – this promotes Yap protein stability and nuclear translocation evidenced by increase in phosphorylated Yap. Myocardial Traf6 deficiency prevents TAC-induced cardiac hypertrophy. Moreover, overexpression of Yap-K237 mutant did not restore TAC-induced cardiac hypertrophy in myocardial Yap deficient mice. Conclusions: Our results demonstrate that non-canonical Yap activation is responsible for pressure overload induced cardiac hypertrophy. Targeting of the newly identified ROS-Traf6-Yap signaling axis may provide a new approach to prevent pathogenic cardiac hypertrophy.

Abstract 4138661: Targeting Arginase I Alleviates Cardiomyopathy

Introduction: Emerging data have shown that pathological cardiac fibrosis and heart failure is driven by recruitment of CD4 + T cells to injured heart tissue. Systemic deletion of CD4 + T cells or splenectomy has been shown to attenuate CD4 + T cell heart infiltration and inflammation. We engineered cargo-less nanoparticles using a biocompatible and biodegradable polymer that target splenic macrophages to overexpress arginase I, leading to local depletion of L-arginine, an amino acid crucial for CD4 + T cell activation and expansion. Hypothesis: Cargo-less nanoparticles attenuate CD4 + T cell activation, expansion, and heart infiltration in experimental models of cardiomyopathy by regulating cross talk between macrophages and CD4 + T cells via L-arginine depletion in the spleen. Methods: Spleen-targeting, cargo-less nanoparticles were synthesized from poly(L-lactide-co-glycolide) (PLLGA) and administered to murine and human macrophages in vitro. Arginase I expression and activity were assessed via Western blotting and arginase activity assay. Epigenetic modulation was analyzed using Western blotting and CHIP-seq. Conditioned media was collected to culture CFSE-labeled T cells to assess proliferation. The nanoparticles were administered to mouse heart failure models induced by isoproterenol or angiotensin II and phenylephrine. Immune cell composition in mouse spleens and hearts was investigated by flow cytometry. Cardiac function was assessed by echocardiography and heart fibrosis was examined via immunohistochemistry and Western blotting. Results: Primary murine macrophages treated with our nanoparticles exhibited a dose-dependent T cell suppression in vitro. This effect was abrogated when an arginase inhibitor was administered together with the nanoparticles. The nanoparticles upregulated arginase I protein expression and arginase activity by increasing histone lactylation. In vivo testing with mouse heart injury models showed that the nanoparticles restored levels of effector and regulatory T cells in injured mice to non-injured levels. Additionally, the nanoparticles reduced cardiac fibrosis and restored ejection fraction. Furthermore, Western blotting of heart tissue lysate revealed that the nanoparticles downregulated the TGFb and p-SMAD signaling pathway. Conclusion: Collectively, these findings highlight a novel therapeutic strategy for heart failure, addressing the gap of fibrosis treatment by targeting upstream immunological pathways.

Experimental Modeling of Heart Failure in Mice

The article presents the results of testing a heart failure model in laboratory animals by single administration of amyloidogen. White outbred mice were used as biomodels, which were divided into intact and experimental groups. Animals from the experimental group were once injected with amyloidogen containing mouse myocardial homogenate to reproduce a pronounced cardiopathic effect. Structural and functional changes of the myocardium were monitored using echocardiography. According to the results obtained, animals in the experimental group demonstrated a remodeling of the heart similar to restrictive cardiomyopathy and a myocardial disfunction of both ventricles, indicating the formation of heart failure.

HUCMSCs Regulate Bile Acid Metabolism to Prevent Heart Failure–Induced Intestinal Injury by Inhibiting the Activation of the STAT3/NF‐κB/MAPK Signaling Pathway via TGR5

ABSTRACTThe protective effects of human umbilical cord mesenchymal stem cells (hUCMSCs) on heart failure (HF)‐induced intestinal injury have not been fully understood. Flow cytometry and immunofluorescence analysis revealed that hUCMSCs renewed themselves, grew, and transformed into various cell types. Meanwhile, hUCMSCs safeguarded against intestinal damage, regulated imbalances in the intestinal flora and bile acid metabolism, and enhanced the levels of hyodeoxycholic acid (HDCA) in pigs with HF. HDCA protected against HF‐induced intestinal injury in mice through Takeda G protein–coupled receptor 5 (TGR5). Protein analysis showed that HDCA exerted protective effects on the intestines via the signal transducer and activator of transcription 3 (STAT3)/nuclear factor kappa B (NF‐κB)/mitogen‐activated protein kinase (MAPK) signaling pathway. Mouse experiments revealed that HDCA bound to TGR5 to inhibit MAPK and NF‐κB signaling pathway activation, which relies on the STAT3 signaling pathway. Moreover, hUCMSCs protected against intestinal injury in the pig model of HF by suppressing the activation of the STAT3/NF‐κB/MAPK signaling pathway via TGR5.

Predictive modeling of preoperative acute heart failure in older adults with hypertension: a dual perspective of SHAP values and interaction analysis

BackgroundIn older adults with hypertension, hip fractures accompanied by preoperative acute heart failure significantly elevate surgical risks and adverse outcomes, necessitating timely identification and management to improve patient outcomes.Research objectiveThis study aims to enhance the early recognition of acute heart failure in older hypertensive adults prior to hip fracture surgery by developing a predictive model using logistic regression (LR) and machine learning methods, optimizing preoperative assessment and management.MethodsEmploying a retrospective study design, we analyzed hypertensive older adults who underwent hip fracture surgery at Hebei Medical University Third Hospital from January 2018 to December 2022. Predictive models were constructed using LASSO regression and multivariable logistic regression, evaluated via nomogram charts. Five additional machine learning methods were utilized, with variable importance assessed using SHAP values and the impact of key variables evaluated through multivariate correlation analysis and interaction effects.ResultsThe study included 1,370 patients. LASSO regression selected 18 key variables, including sex, age, coronary heart disease, pulmonary infection, ventricular arrhythmias, acute myocardial infarction, and anemia. The logistic regression model demonstrated robust performance with an AUC of 0.753. Although other models outperformed it in sensitivity and F1 score, logistic regression’s discriminative ability was significant for clinical decision-making. The Gradient Boosting Machine model, notable for a sensitivity of 95.2%, indicated substantial capability in identifying patients at risk, crucial for reducing missed diagnoses.ConclusionWe developed and compared efficacy of predictive models using logistic regression and machine learning, interpreting them with SHAP values and analyzing key variable interactions. This offers a scientific basis for assessing preoperative heart failure risk in older adults with hypertension and hip fractures, providing significant guidance for individualized treatment strategies and underscoring the value of applying machine learning in clinical settings.

Systems Pharmacology to Explore the Potential Mechanism of Ginseng Against Heart Failure.

The aim of this study is to elucidate the pharmacological mechanism underlying the effects of Ginseng Radix et Rhizoma (ginseng) in heart failure (HF), providing a theoretical foundation for its clinical application. The potential mechanism of ginseng in the context of HF was investigated using systems pharmacology that combined network pharmacology, Gene Expression Omnibus (GEO) analysis, molecular docking, and experimental verification. Network pharmacology was employed to identify drug-disease targets. Core gene targets were subsequently subjected to enrichment analysis by integrating network pharmacology with GEO. Molecular docking was utilized to predict the binding affinities between identified targets and ginseng compounds. Furthermore, the therapeutic efficacy of ginseng was validated in an isoproterenol (ISO)-induced rat model of HF. The modulation of key signaling pathways by ginseng was confirmed through Western blot analysis. A total of 154 potential targets of ginseng in the treatment of HF were identified through network pharmacology analysis. The analysis of GSE71613 revealed that the PI3K-Akt pathway, reactive oxygen species, oxidative phosphorylation, MAPK signaling, and Ras signaling pathways are predominantly associated with patients with HF. By integrating the findings from network pharmacology and GEO analysis, ginsenoside Rg1 and ginsenoside Rb3 were identified as the potential components in ginseng, while FN1 and PRKAA2 were recognized as key targets involved in the PI3K-AKT and AMPK pathways, respectively. Molecular docking analysis revealed a strong affinity between the potential components and the identified core targets. In vivo experiments indicated that the extract of ginseng (EPG) significantly ameliorated ISO-induced cardiac dysfunction by improving cardiac parameters such as cardiac left ventricular internal systolic diameter, left ventricular end-diastolic volume, left ventricular end systolic volume, and left ventricular ejection fraction, while also reducing malondialdehyde production. In addition, EPG was found to enhance superoxide dismutase activity and ATP levels, while concurrently reducing the levels of interleukin (IL)-1β, IL-6, and TNF-α. The extract also reduced myocardial oxygen consumption, inflammatory cell infiltration, and the number of damaged myocardial fibers. Moreover, EPG was observed to upregulate the expression of p-PI3K, p-AKT, p-AMPK, and Bcl-2, while downregulating the expression of p-NFκB, TGF-β, and Bax. The therapeutic effects of ginseng on HF are primarily mediated through the PI3K-Akt and AMPK pathways. Ginsenoside Rg1 and ginsenoside Rb3 have been identified as potential therapeutic agents for HF.

Conditioned Medium from Human Amniotic Membrane-Derived Mesenchymal Stem Cells Modulates Inflammatory and Myofibrotic Factors in Vivo

Background: Heart failure (HF) is a prevalent diagnosis with a significant mortality rate. Various therapeutic approaches exist for treating HF, and human adipose-derived mesenchymal stem cells-conditioned medium (hAMSCs-CM) therapy has emerged as a promising option. Despite its potential efficacy, the precise mechanism of action underlying hAMSCs-CM treatment remains unclear. To address this knowledge gap, we conducted a novel animal study to investigate the mechanism of action of hAMSCs-CM in an HF model, with a specific focus on transforming growth factor-β (TGF-β)/galectin-3, monocyte chemoattractant protein-1 (MCP1), B-type natriuretic peptide (BNP), and aldosterone (ALD). Methods: Forty adult male Wistar rats were divided into 4 groups: control, HF, culture medium, and CM. All rats, except those in the control group, received an injection of isoproterenol to induce an animal model of HF. The CM group was administered the CM, while those in the culture medium group received standard culture media. Subsequently, serum levels of fibrotic factors, including TGF-β/galectin-3, MCP1, BNP, and ALD, were measured using ELISA. Statistical analysis was performed using one-way analysis of variance and the Tukey test. Results: Serum levels of TGF-β/galectin-3, MCP1, BNP, and ALD were significantly elevated in the HF, CM, and culture medium groups compared with the control group (P<0.001). Additionally, these fibrotic factors were significantly reduced in the CM group compared with the HF group (P<0.001). Notably, CM therapy could not restore TGF-β/galectin-3, MCP1, BNP, or ALD levels to the normal range observed in the control group. Conclusion: Our findings indicate that hAMSCs-CM modulates the expression of inflammatory and fibrotic cytokines, such as TGF-β/galectin-3, MCP1, BNP, and ALD, in isoproterenol-induced HF in male rats. These results contribute to a better understanding of the therapeutic mechanisms underlying hAMSCs-CM treatment for HF.

Early Pathological Mechanisms in a Mouse Model of Heart Failure with Preserved Ejection Fraction.

Heart failure with preserved ejection fraction (HFpEF) constitutes more than half of all HF cases, yet evidence-based therapies remain lacking due to limited understanding of its underlying pathological mechanisms. Our study aimed to uncover early pathological mechanisms in HFpEF by exposing mice to dietary conditions resembling a Western diet-rich in fats, salt, and low in fiber-alongside excess mineralocorticoids to replicate significant aspects of human HFpEF. Echocardiography was performed at both 3-week and 6-week intervals post-challenge, revealing cardiac alterations as early as 3-weeks. While ejection fraction remained preserved, mice exhibited signs of diastolic dysfunction, reduced stroke volume, and left atrial enlargement. Additionally, changes in pulmonary flow velocities were noted by the 3-week mark, suggesting elevated pulmonary pressure. Extracardiac comorbidities included organ congestion, increased adiposity, impaired glucose tolerance, and hypercholesterolemia. Molecular analyses unveiled evidence of low-grade inflammation, oxidative stress, and impaired NO-cGMP-PKG signaling, contributing to the observed decrease in titin phosphorylation, thereby impacting myocardial stiffness. Additionally, impaired NO signaling might have influenced the alterations observed in coronary flow reserve. Moreover, dysregulation of calcium signaling in cardiomyocytes and reduced SR load were observed. Interestingly, elevated phosphorylation of cMyBP-C was linked to preserved ejection fraction despite reduced SR load. We also observed intestinal atrophy, possibly due to low dietary fiber intake and diminished gut perfusion, potentially contributing to systemic low-grade inflammation. These findings reveal how excess mineralocorticoids-salt-induced hypertension, and dietary factors, like high-fat and low-fiber intake, contribute to cardiac dysfunction and metabolic disturbances, offering insights into early HFpEF pathology in this model.

Bushen Huoxue Yiqi Formula Alleviates Cardiac Fibrosis in Ischemic Heart Failure through SIRT1/Notch1 Pathway-Mediated EndMT

BackgroundCardiac fibrosis plays a crucial role in the development of heart failure (HF) following myocardial infarction (MI). Endothelial-mesenchymal transition (EndMT) is one of the key drivers of cardiac fibrosis and subsequent cardiac dysfunction. The traditional Chinese medicine formula Bushen Huoxue Yiqi Formula (BHYF) is an effective prescription for treating HF, significantly improving cardiac function in patients. However, the underlying mechanisms of BHYF's efficacy remain inadequately understood. ObjectiveThis study aims to determine whether BHYF ameliorates HF by inhibiting cardiac fibrosis and to elucidate the intrinsic mechanisms involved. MethodsA post-MI HF model was established by ligating the left anterior descending coronary artery in rats, and human umbilical vein endothelial cells (HUVEC) were stimulated with hypoxia/reoxygenation (H/R) in vitro. Active compounds in BHYF were identified using HPLC. Cardiac function and morphology were assessed using echocardiography, TTC staining, HE staining, Masson's trichrome, and Sirius Red staining. The mechanism of action of BHYF was evaluated using Western blotting, immunohistochemistry, and immunofluorescence. ResultsA total of 98 compounds, including glycosides, phenolic compounds, carboxylic acids, and others, were identified or preliminarily identified. BHYF improved cardiac function and myocardial damage in rats with MI-induced HF and mitigated cardiac fibrosis by inhibiting EndMT. Mechanistically, BHYF treatment inhibited EndMT by modulating the SIRT1/Notch1 pathway, thereby exerting anti-fibrotic effects in the heart. ConclusionTargeting EndMT based on the SIRT1/Notch1 pathway, BHYF may represent a novel antifibrotic therapeutic strategy, providing a scientific basis for the development of new cardiovascular drugs.

Risk prediction models for incident heart failure: a systematic review and meta-analysis

Abstract Background Heart failure (HF) risk prediction models combine multivariable patient data to estimate an individual's risk of developing HF. By detecting at-risk and early-stage patients, models may facilitate earlier intervention to prevent or delay HF development. Previous systematic reviews were unable to recommend any existing prediction models for clinical use due to insufficient evidence and lack of guidelines on appraising study quality at their time of publication. Purpose To summarize the performance of risk prediction models for incident HF and identify models for further validation and potential clinical use. Methods We searched MEDLINE and EMBASE in June 2021 for English-language studies developing or validating HF risk prediction models. Studies were also retrieved from two previous systematic reviews. We narratively summarized model characteristics (e.g. model type, predictors used, prediction horizon) and study methodology (e.g. validation methods). Performance was assessed among all models validated in ≥ 1 cohort. For all models validated in ≥ 2 cohorts, we pooled discrimination measures using random-effects meta-analyses. Calibration was descriptively summarized based on individual study results from statistical tests and graph digitization of calibration plots. Study quality was assessed using the Prediction model Risk Of Bias ASsessment Tool (PROBAST). Results Of 18,937 publications screened, 41 studies consisting of 120 prediction models were included. Twenty models were both derived and validated, 99 only derived, and 1 only validated. Risk of bias was rated as high in nearly all (94.7%) PROBAST assessments, mostly attributable to issues with analysis. Among 21 models validated in ≥ 1 cohort, most had moderate (61.9%, C-statistic 0.7 to <0.8) or high (23.8%, C-statistic 0.8 to <0.9) discrimination. In patients with low predicted risk (<10%), the calibration was adequate. Nine (42.9%) of these 21 models were presented as web-based calculators and five (23.8%) as points-based risk scores. Based on performance, number of validation cohorts, study risk of bias, and user friendliness, the Atherosclerosis Risk in Communities (ARIC), Multi-Ethnic Study of Atherosclerosis (MESA), Pooled Cohort equations to Prevent Heart Failure (PCP-HF), and Health ABC models emerged as the most promising risk scores for clinical practice. Conclusions Given their acceptable performance but high risk of bias, future studies should focus on the external validation of these models in studies of high methodological rigor. Models should be validated in a greater diversity of patient populations, particularly with respect to race. Impact analyses assessing how the clinical implementation of these models affects patient outcomes are also required prior to their routine use. Once validated, these models may help guide clinical decision making to prevent the onset of HF with early, aggressive risk factor modification.Discrimination in 21 validated modelsCharacteristics of recommended models

Comprehensive machine learning models for prediction of heart failure in 476,393 women and men from the UK Biobank reveal sex differences and underutilized risk factors

Abstract Background Machine learning (ML) models provide potential advantage over ‘traditional’ regression models in heart failure (HF) prediction. Objective To compare performances of Cox PH models and ML survival models for incident HF in men and women without prevalent ischemic heart disease (IHD). We also aimed to identify potential high-risk precursors otherwise ignored by conventional survival models, and to investigate differences between sex-specific models. Methods We included 476,393 participants (55.6% women) from the UK Biobank, after excluding participants with a history of HF or IHD, and defined sex-specific datasets. We predicted incident HF events using over 400 baseline characteristics. We constructed multivariable Cox PH models, which included all predictor variables and subsequently only those remaining after LASSO stability selection. We also developed two supervised ML models (Random Survival Forest (RSF), eXtreme Gradient Survival Boosting (XGBoost)). We identified the 15 most important sex-specific predictors in each model and performances were compared using the C-index. Models were validated using hold-out sets. Results During 12.3 ± 1.9 years of follow-up, 4680 (1.76%) women and 6631 (3.14%) men developed incident HF. XGBoost showed the best performance during model training (C-index, training: 0.89 in men, 0.97 in women; validation 0.77 in men, 0.80 in women). The multivariable Cox model performed second-best (C-index, training: 0.78 in men, 0.82 in women; validation: 0.76 in men, 0.78 in women). RSF performed slightly worse (C-index, training: 0.75 in men, 0.79 in women; validation: 0.75 in men, 0.79 in women) but did not show performance drop during validation. LASSO stability selection performed similar to RSF. Age, self-reported lifetime treatments and medications, cystatin-C, waist circumference and FEV1-scores were identified as strong risk factors in all models for both sexes. Reduced albumin levels and elevated HbA1c were more strongly associated with high risk in men, while elevated systolic BP showed higher importance in women. Traditional Cox models observed CRP as important only in men, while the ML models identified CRP as important for both sexes. Neutrophil count was considered a strong risk factor in both sexes in the traditional Cox models, yet it was not among the most important predictors in both ML models. Presence of other heart disease (which included a.o. pericardial disease, valve disorders and arrhythmias) was an important predictor variable only in the ML models. Conclusion ML models showed similar performance to Cox PH models for HF prediction. Despite this, differences in predictor importance were identified between models. Sex-specific risk predictors were found, and FEV1 score, which is not commonly included in existing models, was identified as an important risk factor. These results suggest that ML models may reveal additional insights that would otherwise remain unnoticed.

ERBB4 activation prevents microvascular dysfunction in a large animal model of hypertensive heart disease

Abstract Background Coronary microvascular dysfunction (CMD) participates in the pathophysiology of multiple cardiovascular diseases, but treatment options are limited. A new treatment option may include ERBB4 stimulation by neuregulin-1 (NRG1), which has anti-inflammatory, antifibrotic, and cardioprotective effects in models of heart failure. Objectives To assess the effect NRG1/ERBB4 stimulation on CMD in hypertensive heart disease. Methods Hypertensive heart disease was induced in 12 Aachener minipigs by implantation of deoxycorticosterone acetate (DOCA) pellets for 8 weeks and compared to 6 controls. The DOCA pigs were randomized to a weekly infusion of JK07, a NRG1 fusion protein with improved pharmacokinetic and pharmacodynamic properties, or vehicle. Microvascular resistance was measured using the bolus thermodilution method. Results DOCA significantly increased microvascular resistance compared to controls (from 14.5 to 19.9 mmHg.s, p = 0.028). This increase was abrogated by JK07 (11.3 mmHg.s, p = 0.018 vs DOCA). dP/dtmax increased by DOCA compared to controls (from 2415.5 to 4455.5 mmHg/s, p = 0.011), which was also abrogated by JK07 (3107.3 mmHg/s, p = 0.055 vs DOCA). Interstitial left ventricular fibrosis was significantly lower in JK07-treated pigs compared to DOCA only (2.1 vs. 5.4 %, p = 0.026), but without difference in perivascular fibrosis (p = 0.48). JK07 did not affect myocyte cross-sectional area, capillary density, pericyte coverage, or microvascular vessel thickness. Conclusions ERBB4 activation by JK07 is capable to prevent CMD in a DOCA hypertensive pig model. Functional rather than structural alterations may explain the protective effects of JK07 on microvascular resistance.Visual summaryJK07 decreases microvascular resistance