Development Of HFpEF Research Articles

Abstract Mo113: An Ovary-Intact Postmenopausal HFpEF Animal Model.

Background: The incidence of HFpEF in women significantly escalates following the age of menopause. This trend cannot solely be attributed to chronological aging, as evidenced by the more gradual increase in prevalence among men with HFpEF. This pattern suggests that menopause is a provocative event for HFpEF. However, the underlying mechanisms remain elusive and challenging to investigate in human subjects; moreover, the attempt to create HFpEF in ovariectomized (OVX) mice was unsuccessful. We aim to create an animal model of postmenopausal HFpEF that resembles the characteristics of HFpEF in women with natural menopause. Methods: We use the 4-vinyl cyclohexene dioxide (VCD) to induce “ovary-intact” menopause, combined with the 2hit regimen (HFpEF inducing regimen elicited by high-fat diet and nitric oxide synthase inhibitor) to model postmenopausal HFpEF. VCD gradually causes ovarian failure, providing the perimenopausal transition and preserving residual ovarian stroma, mimicking natural menopause. The HFpEF phenotypes were studied at the in vivo LV by pressure-volume (PV) analysis and at the single cell level by intact cell force measurement. Results: The Female-VCD-2hit model demonstrates diastolic dysfunction at both the LV and the cellular levels. At the LV level, the increase in the end-diastolic pressure-volume relation (EDPVR) stiffness coefficient and LV end-diastolic pressure (LVEDP) indicates a heightened stiffness of the LV chamber and an elevation in LV filling pressure, an HFpEF-like condition. At the cardiomyocyte level, the female-VCD-2hit model exhibits an increase in cellular diastolic stiffness, suggesting that the observed LV diastolic stiffness is derived from the stiffness of the cardiomyocytes. We compared the female-VCD-2hit mice with the OVX mice subjected to the 2hit regimen. The 2hit-OVX model showed a milder form of diastolic dysfunction, observed as a smaller increase in LV diastolic stiffness (EDPVR) and normal LV filling pressure (LVEDP). Conclusions: Female mice, either premenopausal or ovariectomized, are more resistant to the development of HFpEF, unlike their ovary-intact menopausal (VCD-treated) counterparts, which exhibit a vulnerability to HFpEF, making the VCD-2hit model a suitable model to study postmenopausal HFpEF. The LV diastolic dysfunction observed in the 2hit model is attributed to mechanical dysfunction at the cardiomyocyte level.

In female weight cycling mice, administration of the mineralocorticoid receptor antagonist finerenone during a phase of calorie restriction prevents the development of HFpEF

In female weight cycling mice, administration of the mineralocorticoid receptor antagonist finerenone during a phase of calorie restriction prevents the development of HFpEF

Inhibition of ferroptosis reverses heart failure with preserved ejection fraction in mice

BackgroundHeart failure with preserved ejection fraction (HFpEF) accounts for approximately 50% of heart failure cases. The molecular mechanisms by which HFpEF leads to impaired diastolic function of the heart have not been clarified, nor have the drugs that target the clinical symptoms of HFpEF patients.MethodsHFpEF chip data (GSE180065) was downloaded from the National Center for Biotechnology Information (NCBI) database. Differentially expressed genes (DEGs) were filtered by the limma package in R and processed for GO and KEGG pathway analyses. Then, ferroptosis-related genes in HFpEF were identified by taking the intersection between DEGs and ferroptosis-related genes. CytoHubba and MCODE were used to screen ferroptosis-related hub DEGs in the protein–protein interaction (PPI) network. Establishment of a mouse HFpEF model to validate the transcript levels of ferroptosis-related hub DEGs and ferroptosis-related phenotypes. Transcript levels of ferroptosis-related hub DEGs and HFpEF phenotypic changes in the hearts of HFpEF mice were further examined after the use of ferroptosis inhibitors.ResultsGO and KEGG enrichment analyses suggested that the DEGs in HFpEF were significantly enriched in ferroptosis-related pathways. A total of 24 ferroptosis-related DEGs were identified between the ferroptosis gene dataset and the DEGs. The established PPI network was further analyzed by CytoHubba and MCODE modules, and 11 ferroptosis-related hub DEGs in HFpEF were obtained. In animal experiments, HFpEF mice showed significant abnormal activation of ferroptosis. The expression trends of the 11 hub DEGs associated with ferroptosis, except for Cdh1, were consistent with the results of the bioinformatics analysis. Inhibition of ferroptosis alters the transcript levels of 11 ferroptosis-related hub DEGs and ameliorates HFpEF phenotypes.ConclusionsThe present study contributes to a deeper understanding of the specific mechanisms by which ferroptosis is involved in the development of HFpEF and suggests that inhibition of ferroptosis may mitigate the progression of HFpEF. In addition, eleven hub genes were recognized as potential drug binding targets.

Association between triglyceride glycemic index and ejection fraction preserved heart failure in hypertensive patients.

The triglyceride-glucose (TyG) index is regarded as an independent predictor of cardiovascular disease consequences and a reliable surrogate measure of insulin resistance (IR). However, the correlation analysis between triglyceride glucose index and heart failure with preserved ejection fraction in patients with essential hypertension remains unknown. A single-center, retrospective study was conducted with patients diagnosed with essential hypertension at the First Affiliated Hospital of Xinjiang Medical University, from December 2018 to September 2020. Participants were selected based on specific inclusion and exclusion criteria, with their clinical data and laboratory tests collected. The study employed Spearman's correlation analysis, logistic regression models, restricted cubic spline plots, and receiver operating characteristic (ROC) curves to investigate the relationships between the TyG index and HFpEF. Out of 1,602 enrolled hypertensive patients, 992 were included in the analysis after applying exclusion criteria. Patients were categorized into tertiles based on the TyG index, which showed that patients in the highest tertile had characteristics associated with a higher risk of HFpEF, including age, body mass index (BMI), systolic blood pressure (SBP), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and left ventricular mass index (LVMI). A significant, independent association between the TyG index and HFpEF was confirmed, with an odds ratio (OR) of 5.127 (95% CI [3.894-6.856]). Furthermore, an S-shaped nonlinear relationship was observed between the TyG index and the incidence of HFpEF (nonlinear p < 0.001). TyG index (AUC: 0.824, 95% CI [0.795-0.854]), NT-proBNP (AUC: 0.840, 95% CI [0.816-0.864]), and LVMI (AUC: 0.847, 95% CI [0.820-0.875]) showed good predictive ability for HFpEF. In addition, the TyG+LVMI combination demonstrated the strongest predictive ability (AUC: 0.907, 95% CI [0.887-0.927]). The study underscores a significant association between IR, as indicated by the TyG index, and the development of HFpEF in hypertensive patients. It highlights the critical role of metabolic dysfunction in the pathophysiology of HFpEF, advocating for a broader perspective on cardiovascular risk management.

Mapping individual cardiac cell types and their contribution in the development of heart failure in a multiple comorbidity porcine model

Abstract Background Heart failure with preserved ejection fraction (HFpEF) is characterized by impaired left ventricular (LV) relaxation and filling due to increased myocardial stiffness and hypertrophy. The development of HFpEF is associated with multiple, interrelated risk factors including obesity, chronic kidney disease (CKD), diabetes mellitus (DM), hypertension. Mechanistic studies have implied that comorbidity-driven chronic inflammation, oxidative stress, and endothelial dysfunction act as contributors to the onset and development of HFpEF. Multiple studies that support this HFpEF paradigm highlight the complexity of the disease with different pathways active in and across different cell types. A recently developed multiple comorbidity swine (MCS) model with DM, CKD hypercholesterolemia, demonstrate inflammation, microvascular endothelial dysfunction and LV diastolic dysfunction. This model mimics the slow progression of disease in patients and is therefore ideal to study the earliest mechanisms underlying HFpEF. Purpose Here we hypothesize that single nuclei RNA (snRNA) sequencing aid in mapping the contribution of each individual cardiac cell cluster to disease development, to improve our mechanistic understanding of HFpEF. Methods We performed snRNA sequencing to analyze the transcriptional landscape of the cardiac environment in the well validated MCS model. Frozen left ventricle myocardial samples of MCS (n=4) and healthy control (n=3) swine were used. Results The analysis included ∼100.000 individual nuclei and offers new insights in cell type specific mechanisms during HFpEF onset and development against the background of common comorbidities. We identified 34 different cell clusters, which together represent 6 major cell types. Besides cardiomyocytes (CMs), endothelial cells (ECs) and fibroblasts, a large population of immune cells and smaller populations of mural cells and neurons were present in both MCS and control swine. IPA pathway analysis predicts transcriptomic changes within the cell clusters in response to comorbidities including activation of semaphoring and estrogen signaling in the largest CM cluster (CM2) and activation of EIF2 signaling in ECs (Fig. 1). Gene set enrichment analysis confirmed the activation of HFpEF paradigm pathways in the MCS dataset. Overlap of human HFpEF heart bulk RNA sequencing data and the MCS dataset showed overlapping disease processes including interferon gamma (IFNG) signaling. Moreover, IFNG signaling and IFNG associated transcription factor STAT1 were activated in most of the CM and EC clusters. Conclusion These findings suggest an essential role of multiple pathways during the onset and development of HFpEF. Further improvement of our understanding of underlying molecular mechanisms and crosstalk between cell populations, could pinpoint drug targets and aid the development of new treatments for HFpEF.Top 5 IPA predicted canonical pathways

Abstract 17631: Diabetic Retinopathy and Risk of Heart Failure Subtypes: The Atherosclerosis Risk in Communities (ARIC) Study

Introduction: Although diabetic retinopathy is associated with higher risk of incident heart failure (HF), its associations with HF subtypes (HF with preserved ejection fraction [HFpEF] and HF with reduced ejection fraction [HFrEF]) largely remain unknown. Hypothesis: Diabetic retinopathy, a microvascular complication of hyperglycemic states, is more strongly associated with HFpEF than with HFrEF. Methods: We included 5038 ARIC participants who underwent fundus photography at Visit 3 (1993-1995), had diabetes or prediabetes, and were free of HF (mean age 60 years, 48% women, 27% Black adults). Retinopathy was graded according to the Early Treatment of Diabetic Retinopathy Study (ETDRS) grading scale, with a severity score ≥14 defining the presence of any retinopathy. We used data on incident HF hospitalization. Information on HF subtypes was only available from 2005 onwards. We used Cox regression to estimate the associations of retinopathy with incident overall HF. For HF subtypes, to account for the competing risks of HFpEF and HFrEF, we used competing risks regression analysis by the proportional sub-hazards Fine and Gray method. Results: Over a median 21.2 years of follow-up, there were 1358 HF events (461 prior to 2005 and 897 post-2005 [including 418 HFpEF and 383 HFrEF]). The presence of diabetic retinopathy conferred higher risk of overall HF (hazard ratio [HR]: 1.84, 95% confidence interval [CI]: 1.55, 2.20). Among participants with information on HF subtypes post-2005 (n= 4120), diabetic retinopathy significantly increased the risk of HFpEF (HR 1.86, 95% CI: 1.28, 2.71), but not of HFrEF (sub-HR: 0.73, 95% CI: 0.45, 1.20). An increasing severity of diabetes retinopathy was associated with increasing risks of overall HF and HFpEF. Conclusions: The presence of diabetic retinopathy signifies an excess risk of HF, primarily HFpEF. Our findings support a strong contribution of microvascular disease to the development of HFpEF.

Abstract P2034: Minimally-invasive Porcine Model For The Study Of Cardiac Remodeling In Type 4 Cardiorenal Syndrome

Background: CKD is on the rise, and over half of patients die due to cardiac causes, usually HF. They present with HF not only due to volume overload, but also because of reno-cardiac interactions of unclear mechanisms termed type 4 cardiorenal syndrome (CRS4). In order to understand CRS4, we developed a pig model using minimally-invasive techniques. Methods: 4 female Yorkshire pigs had staged embolization of the renal arteries. Clot/contrast mix was injected by catheter until no flow was seen on angiography. Echo, pressure measurements, angiography, and urine and blood collection to monitor CKD and HF progression was done monthly. At 4 months, GFR and PV loop measurements were also taken, and tissues harvested. Results: BUN (11.3 ± 0.3 vs 5.3 ± 0.5 mg/dL, p &lt; 0.01) and SCr (2.1 ± 0.2 vs 1.3 ±0.1 mg/dL, p&lt;0.01) increased at the endpoint compared to controls, and GFR declined (6 ± 4 vs 124 ± 17 mL/min, p &lt; 0.01). Kidneys showed diffuse fibrosis on trichrome staining. LV mass (136 ± 6 vs 106 ± 6 g, p &lt; 0.05), EDP (16 ± 2 vs 9 ± 2 mmHg, p &lt;0.05), aortic (146 ± 9 vs 96 ± 5 mmHg, p &lt; 0.01) and pulmonary capillary wedge pressures (12 ± 1 vs 6 ± 1 mmHg, p &lt; 0.01) and PA (22 ± 1 vs 16 ± 1 mmHg, p &lt; 0.05) were increased. PV loop showed increased EDPVR slope (0.36 ± 0.03 vs 0.17 ± 0.03, p &lt; 0.01) and Tau (48.9 ± 1.9 vs 36.3 ± 1.1 ms, p &lt; 0.01). LV was fibrotic. Conclusions: Repetitive clot injection successfully induced CKD, seen by increased SCr and BUN, reduced GFR, and renal fibrosis. At 4 months, the heart was hypertrophic, fibrotic, and had PV relationships indicating development of HFpEF. Therefore, we have developed a successful minimally-invasive large animal model of CRS4 for future studies.

Therapeutic effects on the development of heart failure with preserved ejection fraction by the sodium-glucose cotransporter 2 inhibitor dapagliflozin in type 2 diabetes

BackgroundHeart failure with preserved ejection fraction (HFpEF) is a common disease with high morbidity and lacks effective treatment. We investigated the protective effects of the long-term application of the sodium-glucose cotransporter 2 inhibitor (SGLT2i) dapagliflozin on diabetes-associated HFpEF in a rat model. Serum proteomics and metabolomics analysis were also conducted in type 2 diabetic patients with HFpEF treated with dapagliflozin.MethodsMale Zucker diabetic fatty (ZDF) rats were used as a model of diabetic cardiomyopathy. From weeks 16 to 28, animals were given a vehicle or dapagliflozin (1 mg/kg) once daily. Primary blood biochemistry indices, echocardiography, histopathology, and cardiac hemodynamics were determined during the study period. The key markers of myocardial fibrosis, nitro-oxidative stress, inflammation, apoptosis, autophagy, and AMPK/mTOR signaling were examined. Additionally, healthy controls and individuals with type 2 diabetes were enrolled and 16 serum samples from 4 groups were randomly selected. Serum proteome and metabolome changes after dapagliflozin treatment were analyzed in diabetic individuals with HFpEF.ResultsDapagliflozin effectively prevented the development of HFpEF in rats with diabetes by mitigating nitro-oxidative stress, pro-inflammatory cytokines, myocardial hypertrophy, and fibrosis, reducing apoptosis, and restoring autophagy through AMPK activating and mTOR pathway repressing. Proteomics and metabolomics revealed that cholesterol and high-density lipoprotein particle metabolism, nicotinate and nicotinamide metabolism, arginine biosynthesis, and cAMP and peroxisome proliferator-activated receptor (PPAR) signaling are the major disturbed pathways in HFpEF patients treated with dapagliflozin.ConclusionLong-term treatment with dapagliflozin significantly prevented the development of HFpEF in diabetic rats. Dapagliflozin could be a promising therapeutic strategy in managing HFpEF individuals with type 2 diabetes.

S-51-5: DIFFERENT CONTRIBUTION OF AFFERENT RENAL NERVES TO DEVELOPMENT OF HYPERTENSION AND HYPERTENSIVE HEART FAILURE IN SEVERAL RAT MODELS OF HYPERTENSION

Objective: Renal nerves contain efferent and afferent fibers. Acute stimulation of the afferent nerves increases central sympathetic outflow. This study aimed to investigate the contribution of afferent renal nerves to the development of hypertension and hypertensive heart failure in several rat models of hypertension. Design and method: Selective afferent renal nerve denervation (ARDN) or sham operation was performed in the following models: (1) SHRSP at 9 weeks of age; (2) 4% high-salt diet (HS)-fed SHRSP at 8 weeks (HS from 8 weeks); (3) 8% HS-fed Dahl salt-sensitive rats at 9 weeks (HS from 6 weeks); and (4) 8% HS-fed Dahl salt-sensitive rats at 9 weeks (HS from 7 weeks). Dahl rats fed 0.3% low-salt diet (LS) were used as controls for (3) and (4). Blood pressure (BP) was measured by telemetry in (1) and (2), and by tail-cuff method in (3) and (4). The experimental period ended at the following age: (1) 11 weeks; (2) 11 weeks; (3) 16 weeks (“HFrEF’’ phase); and (4) 19 weeks (“HFpEF’’ phase). Results: (1) Mean BP was significantly elevated from 9 weeks to 11 weeks in sham-SHRSP (155.2 ± 2.0 vs 144.0 ± 1.9 mmHg, n = 10, p &lt; 0.05). Mean BP in ARDN-SHRSP (157.8 ± 2.7 mmHg, n = 10) was not different compared to sham-SHRSP at 11 weeks. (2) Mean BP was significantly increased from 8 weeks to 11 weeks in sham-HS-SHRSP (191.5 ± 8.1 vs 126.5 ± 4.0 mmHg, n = 6, p &lt; 0.05). Mean BP in ARDN-HS-SHRSP (186.0 ± 7.1 mmHg, n = 6) did not differ from sham-HS-SHRSP at 11 weeks. (3) Systolic BP was significantly increased (243.6 ± 7.0 vs 140.0 ± 2.7 mmHg, n = 9 each, p &lt; 0.05) and echocardiographic left ventricular fractional shortening (LVFS) was significantly decreased (25.9 ± 1.7 vs 48.8 ± 0.4 %, p &lt; 0.05) in sham-HS-Dahl rats compared to LS-Dahl rats at 16 weeks. Compared to sham-HS-Dahl rats, systolic BP was not different (223.4 ± 5.5 mmHg, n = 7); however, the decreased LVFS was significantly attenuated (42.2 ± 1.2 %, p &lt; 0.05) in ARDN-HS-Dahl rats. (4) Systolic BP was significantly increased in sham-HS-Dahl rats compared to LS-Dahl rats at 19 weeks (207.8 ± 4.5 vs 135.7 ± 3.2 mmHg, n = 8 and 6, p &lt; 0.05), and this increase was not affected in ARDN-HS-Dahl rats (220.7 ± 2.9 mmHg, n = 7). By echocardiography, LVFS did not differ between the three groups, whereas E/e’ ratio was significantly increased in sham-HS-Dahl rats compared to LS-Dahl rats and was attenuated in ARDN-HS-Dahl rats. Conclusion: The signals from afferent renal nerves contribute to the development of HFrEF and HFpEF without affecting BP in Dahl salt-sensitive hypertensive rats, but not of hypertension in SHRSP and HS-fed SHRSP.

654 ECHOCARDIOGRAPHIC PARAMETERS AND CLINICAL OUTCOMES IN HEART FAILURE WITH PRESERVED EJECTION FRACTION AND CORONARY MICROVASCULAR DYSFUNCTION: A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract Background Heart failure with preserved ejection fraction (HFpEF) represents nowadays the most frequent presentation of heart failure (HF) in patients aged &amp;gt; 65 years. The underlying reason for the failure of the vast majority of randomized controlled trials (RCTs) in HFpEF patients has been identified in the heterogeneity of pathophysiology and clinical phenotype of this clinical syndrome. Coronary microvascular dysfunction (CMD) represents one among various pathophysiological mechanisms, together with pulmonary vascular disease, pericardial restraint, impaired chronotropic reserve and abnormal autonomic tone. Whether CMD-HFpEF endotype differs from the others in terms of echocardiographic parameters and clinical outcomes is still a matter of debate. Therefore, a systematic review and meta-analysis were performed in order to compare HFpEF populations with or without CMD in terms of echocardiographic features and clinical outcomes. Methods We searched for articles published in PubMed, Scopus and Wiley comparing HFpEF population with or without CMD up to 1st September 2022. Observational studies, reporting echocardiographic parameters mentioned in HFA-PEFF score and/or clinical time to event data, were included. E/e’ ratio, left atrial volume index (LAVi) and left ventricular mass index (LVMi) constituted our three parameters of choice and Hedge's g was the summary effect size. The composite of HF hospitalization and all-cause death represented our clinical endpoint. Meta-regressions according to follow-up time were performed in order to explore potential heterogeneity sources across studies. Results We identified 9 prospective observational studies, enrolling 797 patients with HFpEF. On pooled analysis, patients with CMD present a more severe echocardiographic phenotype, determined by a higher LAVi [effect size (ES) 0.40; Confidence Interval (CI) 0.11, 1.69], E/e’ ratio (ES 0.65; CI 0.28, 1.02) and LVMi (ES 0.27; CI 0.01, 0.53) compared to no-CMD patients. Furthermore, CMD patients showed a significant higher rate of the composite endpoint of all-cause-death and hospitalization for HF (HR 3.22, CI 1.2-8.5, p 0.02). At meta-regression, a significant correlation was found between logarithmic hazard ratios and follow-up time reported (z=2.03, p value 0.04), suggesting that long-term follow-up of CMD-HFpEF patients is required to track the natural trajectory of the disease. Conclusions Aside from being considered a pathophysiological hallmark in the development of HFpEF, CMD seems to play an aggravating role in the progression of the disease, leading both to more severe echocardiographic parameters and worse clinical outcomes compared to other endotypes. Thus, different echocardiographic thresholds could allow for a better prognostic stratification and for identifying the subset of patients who deserve a CMD assessment and who are eventually more likely to benefit from drugs targeting CMD.

Abstract 10196: Reducing Symptom Burden Using Ubiquinol And/Or D-Ribose in Patients With Heart Failure With Preserved Ejection Fraction

Introduction: Mitochondrial dysfunction has been implicated in the development of HFpEF, particularly a decrease in the production of adenosine triphosphate (ATP). Ubiquinol is produced in the mitochondria and is required for oxidative phosphorylation and D-ribose is an essential component of ATP. Thus, supplementing with ubiquinol and/or D-ribose could be useful to improve mitochondrial biomechanics and patient symptoms. Hypothesis: To determine if ubiquinol and/or D-ribose would reduce the symptoms and improve cardiac performance in patients with HFpEF. Methods: This study was a randomized, double-blind, placebo-controlled trial of 216 patients with HFpEF. Four study groups received various supplements over 12 weeks: Group 1 - placebo capsules and placebo powder (placebo group); Group 2 - ubiquinol (600 mg/day) and placebo D-ribose; Group 3 - placebo ubiquinol with D-ribose (15 g/day); Group 4 - ubiquinol (600 mg/day) and D-ribose (15 g/day). There were seven outcome measures for this study: Kansas City Cardiomyopathy Questionnaire (KCCQ) clinical summary score (CSS), level of vigor using a subscale from the Profile of Mood States (POMS), ejection fraction (EF), the ratio of mitral peak velocity of early filling (E) to early diastolic mitral annular velocity (eꞌ) (septal E/eꞌ ratio), B-type natriuretic peptides (BNP), lactate/ATP ratio, and the 6-minute walk test (6MWT). Results: Using ubiquinol and/or D-ribose significantly increased the KCCQ clinical summary score (17.30 to 25.82 points [compared to Group 1, p = 0.0001 (Group 2); p &lt; 0.0001 (Group 3); p=0.0116 (Group 4)], vigor score (7.65 to 8.15 points [all p &lt; 0.0001]), EF (7.08 to 8.03% [p = 0.0006; p &lt; 0.0001; p = 0.0002]), and decreased BNP (-72.02 to -47.51 pg/mL [p = 0.0002; p = 0.0024; p = 0.0415]) and lactate/ATP ratio (-4.32x10 -4 to -3.35x10 -4 mmol/L/RLU) [p &lt; 0.0001; p &lt; 0.0001; p = 0.0006]). We found no significant improvement in septal E/e’ or 6MWT. Conclusions: The use of ubiquinol and/or D-ribose significantly decreased the patients’ symptoms of HFpEF and improved EF. This suggests that the ubiquinol and/or D-ribose increased mitochondrial function by increasing cellular ATP &amp; may help reduce symptom burden and improve cardiac function. NIH: 1R01AG054486-01A1, NCT03133793, IND: 134633

Asymptomatic Left Ventricular Hypertrophy Is a Potent Risk Factor for the Development of HFpEF but Not HFrEF: Results of a Retrospective Cohort Study.

(1) Background: The structural and functional features of the natural history of asymptomatic hypertensive left ventricular hypertrophy (LVH) are not clearly defined. (2) Objective: To determine structural and functional changes in asymptomatic hypertensive LVH, as well as the incidence and predictors of the transition to different phenotypes of heart failure (HF) after a long-term follow-up. (3) Methods: Based on the assessment of chart reviews, we retrospectively selected 350 asymptomatic patients with hypertensive concentric LVH and LV ejection fraction (EF) ≥ 50%. After a median follow-up of 8.1 years, 223 patients had a re-assessment. The final diagnosis (HF with reduced EF [HFrEF], or HF with preserved EF [HFpEF]) was established according to current recommendations. (4) Results: After a follow-up, only 13% of patients remained asymptomatic, 72% developed HFpEF, and 15% developed HFrEF. The transition to HFpEF was associated with an increase in LV diastolic dysfunction grade in 62% of patients. Multivariable analysis identified age, duration of hypertension, interval changes in LV mass, and a lack of statin treatment as independent predictors of HFpEF. Among 34 patients who developed HFrEF, 16 patients (7% of the whole group) had no interval myocardial infarction, corresponding to an internal mechanism of systolic dysfunction. All these 16 patients had mild systolic dysfunction (LVEF > 40%). Baseline LVEF and LV end-diastolic dimension, and interval atrial fibrillation were identified as predictors of internal HFrEF. (5) Conclusions: The majority of patients with asymptomatic LVH developed HFpEF after long-term follow-up, which was associated with the deterioration of LV diastolic dysfunction and a lack of statin treatment. In contrast, the transition to HFrEF was infrequent and characterized by mild LV systolic dysfunction.

P53‐Dependent Mitochondrial Compensation in Heart Failure With Preserved Ejection Fraction

BackgroundHeart failure with preserved ejection fraction (HFpEF) accounts for 50% of patients with heart failure. Clinically, HFpEF prevalence shows age and gender biases. Although the majority of patients with HFpEF are elderly, there is an emergence of young patients with HFpEF. A better understanding of the underlying pathogenic mechanism is urgently needed. Here, we aimed to determine the role of aging in the pathogenesis of HFpEF.Methods and ResultsHFpEF dietary regimen (high‐fat diet + Nω‐Nitro‐L‐arginine methyl ester hydrochloride) was used to induce HFpEF in wild type and telomerase RNA knockout mice (second‐generation and third‐generation telomerase RNA component knockout), an aging murine model. First, both male and female animals develop HFpEF equally. Second, cardiac wall thickening preceded diastolic dysfunction in all HFpEF animals. Third, accelerated HFpEF onset was observed in second‐generation telomerase RNA component knockout (at 6 weeks) and third‐generation telomerase RNA component knockout (at 4 weeks) compared with wild type (8 weeks). Fourth, we demonstrate that mitochondrial respiration transitioned from compensatory state (normal basal yet loss of maximal respiratory capacity) to dysfunction (loss of both basal and maximal respiratory capacity) in a p53 dosage dependent manner. Last, using myocardial‐specific p53 knockout animals, we demonstrate that loss of p53 activation delays the development of HFpEF.ConclusionsHere we demonstrate that p53 activation plays a role in the pathogenesis of HFpEF. We show that short telomere animals exhibit a basal level of p53 activation, mitochondria upregulate mtDNA encoded genes as a mean to compensate for blocked mitochondrial biogenesis, and loss of myocardial p53 delays HFpEF onset in high fat diet + Nω‐Nitro‐L‐arginine methyl ester hydrochloride challenged murine model.

Renal inflammatory signaling alters cardiomyocyte kinetics and lead to HFpEF in CKD: A mechanistic proof of concept study

BackgroundChronic kidney disease (CKD) carries a higher cardiovascular mortality and is a prominent risk factor for development of HFpEF. However, the pathophysiology of HFpEF in CKD has not been established. We have recently shown that experimental CKD‐HFpEF is associated with increased renal release of inflammatory cytokines, particularly tumor necrosis factor (TNF)‐α and interleukin (IL)‐6, to the systemic circulation. Using a unique physiological biomimetic heart culture system, we test whether inflammatory cytokines of kidney origin contribute to the development of HFpEF in CKD.MethodsPigs (4 each) were assigned to sham or CKD (bilateral renovascular disease and dyslipidemia) groups and followed for 14 weeks. Circulating levels of TNF‐α and IL‐6 were quantified (ELISA). In a biomimetic heart culture system, pig heart slices were exposed to plasma from normal or CKD pigs, or from normal pigs enriched with TNF‐α and IL‐6 (matching CKD concentration) with or without cytokine neutralizing antibodies (NA). Contractility and relaxation kinetics in vitro were determined in a dose/time dependent manner.ResultsCKD‐HFpEF pigs exhibited elevated systemic levels of TNF‐α and IL‐6 (Figure 1A), associated with renal dysfunction, cardiac hypertrophy and fibrosis, and diastolic dysfunction. Plasma was collected from all animals. Then, pig heart slices were exposed to CKD‐HFpEF, normal, or normal plasma enriched with cytokines, showing impaired contractility and speed of relaxation that improved after TNF‐α and IL‐6 neutralization (Figure 1B).ConclusionsOur observations implicate circulating inflammatory mediators released by dysfunctional kidneys in imposing damage to the remote myocardium, supporting a role of inflammatory cytokines of renal origin in renal‐cardio pathophysiology in CKD‐HFpEF.

HMGB1-Promoted Neutrophil Extracellular Traps Contribute to Cardiac Diastolic Dysfunction in Mice.

BackgroundHeart failure with preserved ejection fraction (HFpEF) remains an increasing public health problem with substantial morbidity and mortality but with few effective treatments. A novel inflammatory mechanism has been proposed, but the inflammatory signals promoting the development of HFpEF remain greatly unknown.Methods and ResultsSerum of patients with HFpEF was collected for measurement of circulating neutrophils and markers of neutrophil extracellular traps (NETs). To induce HFpEF phenotype, male C57BL/6 mice underwent uninephrectomy, received a continuous infusion of d‐aldosterone for 4 weeks, and maintained on 1.0% sodium chloride drinking water. Heart tissues were harvested, immune cell types determined by flow cytometry, NETs formation by immunofluorescence, and western blotting. Differentiated neutrophils were cultured to investigate the effect of HMGB1 (high mobility group protein B1) and SGLT2 (sodium‐glucose cotransporter‐2) inhibitor on NETs formation in vitro. Circulating neutrophils and NETs markers are elevated in patients with HFpEF, as are cardiac neutrophils and NETs formation in HFpEF mice. NETs inhibition with deoxyribonuclease 1 in experimental HFpEF mice reduces heart macrophages infiltration and inflammation and ameliorates cardiac fibrosis and diastolic function. Damage‐associated molecular pattern HMGB1 expression is elevated in cardiac tissue of HFpEF mice, and HMGB1 inhibition reduces heart neutrophil infiltration and NETs formation and ameliorates diastolic function. Lastly, SGLT2 inhibitor empagliflozin down‐regulates heart HMGB1 expression, attenuates NETs formation and cardiac fibrosis, and improves diastolic function in HFpEF mice.ConclusionsNETs contribute to the pathogenesis of HFpEF, which can be ameliorated by HMGB1 inhibition and SGLT2 inhibitors. Thus, HMGB1 and NETs may represent novel therapeutic targets for the treatment of HFpEF.

Low level transcutaneous vagus nerve stimulation reverses cardiac dysfunction and changes left ventricular gene expression in a rat model of heart failure with preserved ejection fraction

Abstract Introduction Heart failure with preserved ejection fraction (HFpEF) has become a major public health concern, accounting for approximately half of all heart failure patients. Despite normal or near normal left ventricular ejection fraction, HFpEF is associated with increased morbidity and mortality. The complex pathophysiology of HFpEF is not yet fully understood. Inflammation and fibrosis play a central role in the development of HFpEF. We have previously shown that low-level transcutaneous vagus nerve stimulation (LLTS) is anti-inflammatory. The goal of this study was to determine the effect of chronic intermittent LLTS on cardiac fibrosis, diastolic dysfunction, and left ventricular (LV) gene expression in a rat model of HFpEF. Methods Dahl salt-sensitive (DSS) rats were randomized into high salt (HS, 8% NaCl) or low salt (LS) diet (0.3% NaCl) at 7 weeks of age. The animals were monitored for the development of HFpEF on a daily basis. After 6 weeks of LS or HS diets, HS rats were randomized into 4 groups: HS active LLTS (n=50), HS sham LLTS (n=48), HS plus olmesartan (n=14) and HS active LLTS plus methyllycaconitine (MLA) (n=36), a specific blocker of the α7-nicotinic acetylcholine receptor (a7nAChR), which mediates the anti-inflammatory effects of LLTS. Stimulation was delivered for 30 min daily (20Hz, 3mA) for 4 weeks. Echocardiography was performed at 13 weeks (baseline) and 17 weeks (endpoint). At endpoint, LV histology and gene expression were examined. Results After 6 weeks of diets, HS rats developed hypertension and LV hypertrophy compared to LS rats. At endpoint, LLTS significantly attenuated blood pressure elevation, prevented the deterioration of diastolic function and improved LV circumferential strain, compared to the HS sham LLTS group. LV fibrosis was decreased in the HS active LLTS compared to HS sham LLTS group. MLA attenuated this effect, suggesting that the anti-inflammatory effect of LLTS is necessary to prevent fibrosis in this model (Figure 1). RNA-seq analysis revealed that LLTS significantly changed the expression of genes involved in mitochondrial dysfunction, sitruin signaling pathway, and oxidative phosphorylation. Conclusion Autonomic modulation with LLTS attenuates the unfavorable changes of echocardiographic parameters and LV fibrosis induced by HS diet through its anti-inflammatory effects. The results support our hypothesis that inhibiting the anti-inflammatory effect of LLTS attenuates the antifibrotic effect. The obtained data suggest that LLTS may be used clinically as a novel non-invasive neuromodulation therapy for the treatment of HFpEF. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Institutes of Health (NIH)

Effect of diabetes mellitus on the development of left ventricular contractile dysfunction in women with heart failure and preserved ejection fraction

BackgroundHeart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome with sex-specific pathophysiology. Estrogen deficiency is believed to be responsible for the development of HFpEF in women. However, estrogen deficiency does not seem to be completely responsible for the differences in HFpEF prevalence between sexes. While diabetes mellitus (DM) frequently coexists with HFpEF in women and is associated with worse outcomes, the changes in myocardial contractility among women with HFpEF and the DM phenotype is yet unknown. Therefore, we aimed to investigate sex-related differences in left ventricular (LV) contractility dysfunction in HFpEF comorbid with DM.MethodsA total of 224 patients who underwent cardiac cine MRI were included in this study. Sex-specific differences in LV structure and function in the context of DM were determined. LV systolic strains (global longitudinal strain [GLS], circumferential strain [GCS] and radial strain [GRS]) were measured using cine MRI. The determinants of impaired myocardial strain for women and men were assessed.ResultsThe prevalence of DM did not differ between sexes (p > 0.05). Despite a similar LV ejection fraction, women with DM demonstrated a greater LV mass index than women without DM (p = 0.023). The prevalence of LV geometry patterns by sex did not differ in the non-DM subgroup, but there was a trend toward a more abnormal LV geometry in women with DM (p = 0.072). The magnitudes of systolic strains were similar between sexes in the non-DM group (p > 0.05). Nevertheless, in the DM subgroup, there was significant impairment in women in systolic strains compared with men (p < 0.05). In the multivariable analysis, DM was associated with impaired systolic strains in women (GLS [β = 0.26; p = 0.007], GCS [β = 0.31; p < 0.001], and GRS [β = −0.24; p = 0.016]), whereas obesity and coronary artery disease were associated with impaired systolic strains in men (p < 0.05).ConclusionsWomen with DM demonstrated greater LV contractile dysfunction, which indicates that women with HFpEF comorbid with DM have a high-risk phenotype of cardiac failure that may require more aggressive and personalized medical treatment.

Abstract MP06: Insights Into The Role Of Anp In Hfpef During Ss Hypertension

Background: Atrial natriuretic peptide ( ANP) is a hormone produced primarily in the heart, which induces vasodilation and natriuresis. We showed previously that a knockout of ANP in Dahl SS rat results in hypertension and HFpEF phenotype. There is a gap in knowledge regarding the role of inflammation and mitochondrial function in HFpEF that accompanies SSH. We hypothesize that the ANP deficiency in SSH leads to pressure overload, which affects cardiac inflammation and mitochondrial function. Methods: At 8 weeks of age, male wild type (SS WT ) and Nppa knockout (ANP knockout, SS Nppa-/- ) Dahl SS rats were placed on normal salt ( NS , 0.4% NaCl) or a high salt ( HS , 4% NaCl) for 21 days. Tissues were harvested for histological and Western analysis. TEM was used to obtain electron micrographs. EPR spectroscopy was performed in snap-frozen tissues post injection of POBN. 2-way ANOVA was employed for statistical comparison. Results: Heart-to-body-weight ratio was higher in SS Nppa-/- rats (p&lt;0.001), on NS and HS diet ( p &lt;0.001). SS Nppa-/- rats displayed increases in cardiac fibrosis following HS diet ( p &lt;0.01). EPR demonstrated that SS Nppa-/- hearts exhibit a trend for increased lipid peroxidation compared to SS WT . Cardiac cytokine profile demonstrated an increase in IL-1α, IL-1β, L-6, IL-17, TNF-α, sICAM-1, MIP-1α, MIP-3α, in the SS WT rats fed a HS diet vs NS diet, and lower levels of these in the HS-diet fed SS Nppa-/- rats vs SS WT . HS diet was sufficient to induce increases in mitochondrial area ( p &lt;0.001), and decreases in density ( p 0.001), and overall health score ( p &lt;0.001) in both SS WT and SS Nppa-/- rats, but no genotype-specific differences were reported. We observed changes in fission/fusion proteins: Opa1 expression was elevated in SS Nppa-/- vs SS WT ( p &lt;0.01), and Parkin expression was lower in all rats on a HS diet ( p &lt;0.05). Conclusions: Although SS Nppa-/- rats develop a HFpEF phenotype, exacerbated cardiac fibrosis and higher lipid peroxidation vs SS WT rats, inflammation and overall mitochondrial damage are diminished in the hearts of these animals at day 21 of the HS diet. Further studies are needed to elucidate the mechanisms by which inflammation may affect the development of HFpEF during SS hypertension in a cell-specific and time-dependent manner.

Abstract 15172: Murf1 Inhibitor Embl205 is a New Approach for Treatment of Heart Failure With Preserved Ejection Fraction in an Animal Model

Background: The novel MuRF1 inhibitor EMBL205 attenuates effectively developing skeletal muscle atrophy and dysfunction in animals with heart failure with preserved ejection fraction (HFpEF, ZSF1 rat model). The impact of EMBL205 on myocardial function in the HFpEF setting is currently unknown and was evaluated in ZSF1 rats. Methods: 20 wks-old female obese ZSF1 rats received EMBL205 (12 wks, conc. of 0.1% in chow; HFpEF-EMBL205). Age-matched untreated lean (con) and obese (HFpEF) ZSF1 rats served as controls. At 32 wks of age left ventricular (LV)-, aortic valve (AV) function and LV end diastolic pressure (LVEDP) was determined by echocardiography and invasive hemodynamic measurements. LV expression of collagen 1A (Col1A) and 3A (Col3A) was assessed by qRT-PCR, MMP2 expression was obtained by zymography and perivascular fibrosis was quantified in histological sections. Results: Development of HFpEF in ZSF1 obese animals is associated with cardiac enlargement and hypertrophy, as evident by increased myocardial weight, an increase in end diastolic volume (EDV) and LV anterior and posterior wall diameters. Diastolic LV-function is disturbed with elevation of E/é, an increased LVEDP and a preserved LV ejection fraction. AV peak velocity and peak gradient are significantly increased and AV opening area (AVA) significantly decreased. Col1A and Col3A expression are increased in HFpEF animals. EMBL205 treatment results in a significant reduction of myocardial weight and a trend towards lower EDV compared to HFpEF group. EMBL205 attenuates the increase in E/é, LVEDP, AV peak gradient and the decrease of AVA. EMBL205 significantly reduces Col3A expression and a trend for Col1A expression is seen. Increased perivascular fibrosis and MMP2 expression in HFpEF is extenuated by EMBL205 treatment (table 1). Conclusions: Application of EMBL205 attenuated the development of pathological myocardial alterations associated with HFpEF in ZSF1rats due to antifibrotic effects.

Heart and lung aquaporins play a major role in severity of heart failure with preserved ejection fraction in mice and differs between comorbidities

Abstract Introduction Heart failure (HF) is a major public health problem worldwide. To date, HF with preserved ejection fraction (EF, HFpEF) represents half of all HF patients and its prevalence is increasing. HFpEF is associated with multiple comorbidities, including diabetes mellitus, pulmonary and systemic hypertension and obesity, mainly in elderly population. Accurately phenotyping HFpEF is crucial for the development of new therapies, appropriate patient stratification and the implementation of a personalised medicine. Cardiac and pulmonary remodelling play a major role in HFpEF severity but the specific mechanisms underlying cardiac failure and lung congestion, the last stage in HFpEF, in each comorbidity are incompletely understood, precluding the development of effective therapies. Aquaporins (AQP) are membrane proteins serving as water channels across the plasma membrane and control intra- and extracellular fluid volume and prompt to tissue oedema in many organs. However, its specific contribution in HFpEF has not been explored. Purpose We aimed to identify cardiac and pulmonary molecular changes associated to dysfunction and oedema in HFpEF, specific for each comorbidity. Methods A total of 48 C57BL/6 mice 10 weeks old were randomised to the following groups: control (Ctl; n=9), type I diabetes (Db; n=9), chronic hypoxia (PAH; n=10), obesity (Ob; n=10) and systemic arterial hypertension (SAH; n=10). Mice were followed for up to 2.5 years by echocardiography and lung ultrasound until they developed pulmonary oedema (HF) or died naturally. Lungs and heart were extracted and changes were determined by proteomic, immunohistochemistry and qRT-PCR. Results Diastolic dysfunction was observed in all comorbidities and above 50% of those mice developed HF. Db presented the highest ratio in developing HF. Db also showed the earliest mortality (47 weeks), whereas PAH, Ob and SAH mice survived for 82, 92 and 99 weeks, respectively (p&amp;lt;0.001 vs Ctl). A common finding in all groups was the development of different degrees o perivascular fibrosis. Db mice, the HFpEF severest group, showed an increase in pulmonary AQP1 and 5 (p&amp;lt;0.05 and p&amp;lt;0.001, respectively, vs Ctl). Upregulation of AQPs correlated with increased ventricular filling pressures (E/E', r2=07). Cardiac AQP4 was also markedly elevated in Db mice in left and right ventricle (p&amp;lt;0.001 and p=0.01, respectively, vs Ctl). Conclusion Increased AQPs in the lung is associated with a more aggressive development of congestion and HFpEF. In addition, increased AQP4 in the heart in the most aggressive form of HFpEF suggests a relevant role in cardiac oedema. Targeting AQPs in HFpEF may prevent oedema and decompensation. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): This study was supported from the Spanish Ministerio de Economía y Competitividad (RTI2018-096961-B-I00, SAF2015-65722-R and SAF2012-31451 to E.L-P. and Juan de la Cierva Incorporaciόn to M,V-O). The CNIC is supported by the Ministerio de Ciencia, Innovaciόn y Universidades (MCNU) and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (SEV-2015-0505).