Evaluation and management of heart failure with preserved ejection fraction

Sex-specific cardiovascular remodeling leads to a divergent sex-dependent development of heart failure in aged hypertensive rats

INTRODUCTION

The prevalence of heart failure with preserved ejection fraction (HFpEF) is continuously rising and predominantly affects older women often hypertensive and/or obese or diabetic. Indeed, there is evidence on sex differences in the development of HF. Hence, we studied cardiovascular performance dependent on sex and age as well as pathomechanisms on a cellular and molecular level.

METHODS

We studied 15-week- and 1-year-old female and male hypertensive transgenic rats carrying the mouse Ren-2 renin gene (TG) and compared them to wild-type (WT) controls at the same age. We tracked blood pressure and cardiac function via echocardiography. After sacrificing the 1-year survivors we studied vascular smooth muscle and endothelial function. Isolated single skinned cardiomyocytes were used to determine passive stiffness and Ca2+-dependent force. In addition, Western blots were applied to analyse the phosphorylation status of sarcomeric regulatory proteins, titin and of protein kinases AMPK, PKG, CaMKII as well as their expression. Protein kinase activity assays were used to measure activities of CaMKII, PKG and angiotensin-converting enzyme (ACE).

RESULTS

TG male rats showed significantly higher mortality at 1 year than females or WT male rats. Left ventricular (LV) ejection fraction was specifically reduced in male, but not in female TG rats, while LV diastolic dysfunction was evident in both TG sexes, but LV hypertrophy, increased LV ACE activity, and reduced AMPK activity as evident from AMPK hypophosphorylation were specific to male rats. Sex differences were also observed in vascular and cardiomyocyte function showing different response to acetylcholine and Ca2+-sensitivity of force production, respectively cardiomyocyte functional changes were associated with altered phosphorylation states of cardiac myosin binding protein C and cardiac troponin I phosphorylation in TG males only. Cardiomyocyte passive stiffness was increased in TG animals. On a molecular level titin phosphorylation pattern was altered, though alterations were sex-specific. Thus, also the reduction of PKG expression and activity was more pronounced in TG females. However, cardiomyocyte passive stiffness was restored by PKG and CaMKII treatments in both TG sexes.

CONCLUSION

Here we demonstrated divergent sex-specific cardiovascular adaptation to the over-activation of the renin-angiotensin system in the rat. Higher mortality of male TG rats in contrast to female TG rats was observed as well as reduced LV systolic function, whereas females mainly developed HFpEF. Though both sexes developed increased myocardial stiffness to which an impaired titin function contributes to a sex-specific molecular mechanism. The functional derangements of titin are due to a sex-specific divergent regulation of PKG and CaMKII systems.

NASH triggers cardiometabolic HFpEF in aging mice

Both heart failure with preserved ejection fraction (HFpEF) and non-alcoholic fatty liver disease (NAFLD) develop due to metabolic dysregulation, has similar risk factors (e.g., insulin resistance, systemic inflammation) and are unresolved clinical challenges. Therefore, the potential link between the two disease is important to study. We aimed to evaluate whether NASH is an independent factor of cardiac dysfunction and to investigate the age dependent effects of NASH on cardiac function. C57Bl/6 J middle aged (10 months old) and aged mice (24 months old) were fed either control or choline deficient (CDAA) diet for 8 weeks. Before termination, echocardiography was performed. Upon termination, organ samples were isolated for histological and molecular analysis. CDAA diet led to the development of NASH in both age groups, without inducing weight gain, allowing to study the direct effect of NASH on cardiac function. Mice with NASH developed hepatomegaly, fibrosis, and inflammation. Aged animals had increased heart weight. Conventional echocardiography revealed normal systolic function in all cohorts, while increased left ventricular volumes in aged mice. Two-dimensional speckle tracking echocardiography showed subtle systolic and diastolic deterioration in aged mice with NASH. Histologic analyses of cardiac samples showed increased cross-sectional area, pronounced fibrosis and Col1a1 gene expression, and elevated intracardiac CD68+ macrophage count with increased Il1b expression. Conventional echocardiography failed to reveal subtle change in myocardial function; however, 2D speckle tracking echocardiography was able to identify diastolic deterioration. NASH had greater impact on aged animals resulting in cardiac hypertrophy, fibrosis, and inflammation.

Semaglutide versus placebo in patients with heart failure and mildly reduced or preserved ejection fraction: a pooled analysis of the SELECT, FLOW, STEP-HFpEF, and STEP-HFpEF DM randomised trials

BACKGROUND

Heart failure with mildly reduced or preserved ejection fraction (hereafter referred to as HFpEF) is the most common type of heart failure and is associated with a high risk of hospitalisation and death, especially in patients with overweight, obesity, or type 2 diabetes. In the STEP-HFpEF and STEP-HFpEF DM trials, semaglutide improved heart failure-related symptoms and physical limitations in participants with HFpEF. Whether semaglutide also reduces clinical heart failure events in this group remains to be established.

METHODS

We conducted a post-hoc pooled, participant-level analysis of four randomised, placebo-controlled trials (SELECT, FLOW, STEP-HFpEF, and STEP-HFpEF DM) to examine the effects of once-weekly subcutaneous semaglutide (2·4 mg in SELECT, STEP-HFpEF, and STEP-HFpEF DM; 1·0 mg in FLOW) on heart failure events. The STEP-HFpEF and STEP-HFpF DM trials enrolled participants with obesity-related HFpEF, the SELECT trial enrolled participants with atherosclerotic cardiovascular disease and overweight or obesity, and the FLOW trial enrolled participants with type 2 diabetes and chronic kidney disease. Hence, for this analysis, we include all participants from the STEP-HFpEF trials and those with an investigator-reported history of HFpEF from SELECT and FLOW. The main outcomes for this analysis were the composite endpoint of time to cardiovascular death or first worsening heart failure event (defined as hospitalisation or urgent visit due to heart failure), time to first worsening heart failure event, and time to cardiovascular death. Efficacy and safety endpoints were analysed with the full analysis set (ie, all participants randomly assigned to treatment, according to the intention-to-treat principle). The SELECT, FLOW, STEP-HFpEF, and STEP-HFpEF DM trials are registered at ClinicalTrials.gov, NCT03574597, NCT03819153, NCT04788511, and NCT04916470, respectively, and all are complete.

FINDINGS

Across the four trials, 3743 (16·8%) of 22 282 participants had a history of HFpEF (1914 assigned to semaglutide and 1829 assigned to placebo). In this group of participants with HFpEF, semaglutide reduced the risk of the combined endpoint of cardiovascular death or heart failure events (103 [5·4%] of 1914 in the semaglutide group had events vs 138 [7·5%] of 1829 in the placebo group; hazard ratio [HR] 0·69 [95% CI 0·53-0·89]; p=0·0045). Semaglutide also reduced the risk of worsening heart failure events (54 [2·8%] vs 86 [4·7%]; HR 0·59 [0·41-0·82]; p=0·0019). No significant effect on cardiovascular death alone was seen (59 [3·1%] vs 67 [3·7%]; HR 0·82 [0·57-1·16]; p=0·25). A lower proportion of patients treated with semaglutide had serious adverse events than did those who were treated with placebo (572 [29·9%] vs 708 [38·7%]).

INTERPRETATION

In patients with HFpEF, semaglutide reduced the risk of the combined endpoint of cardiovascular death or worsening heart failure events, and worsening heart failure events alone, whereas its effect on cardiovascular death alone was not significant. These data support the use of semaglutide as an efficacious therapy to reduce the risk of clinical heart failure events in patients with HFpEF, for whom few treatment options are currently available.

FUNDING

Novo Nordisk.

The Atrial Fibrillation and Heart Failure with Preserved Ejection Fraction "Twindemic" - Shared Root Causes and Treatment Targets

Heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) are comorbid conditions that are increasingly prevalent and have a high socioeconomic burden. This article discusses their shared pathophysiology, focusing on the triad of hypertension, obesity, and aging. We highlight the misperception that pharmacologic heart rate lowering is beneficial, which has resulted in an overprescription of beta-blockers in HFpEF and AF. In contrast, heart rate modulation through accelerated pacing provides hemodynamic and structural advantages, which have yielded significant improvements in quality of life, physical activity, and AF burden in the myPACE trial of patients with preclinical or overt HFpEF.

Effect of exercise training in patients with chronotropic incompetence and heart failure with preserved ejection fraction: Training-HR study protocol

BACKGROUND

Chronotropic incompetence (ChI) is linked with diminished exercise capacity in heart failure with preserved ejection fraction (HFpEF). Although exercise training has shown potential for improving functional capacity, the exercise modality associated with greater functional and chronotropic response (ChR) is not well-known. Additionally, how the ChR from different exercise modalities mediates functional improvement remains to be determined. This study aimed to evaluate the effect of three different exercise programs over current guideline recommendations on peak oxygen consumption (peakVO2) in patients with ChI HFpEF phenotype.

METHODS AND RESULTS

In this randomized clinical trial, 80 stable symptomatic patients with HFpEF and ChI (NYHA class II-III/IV) are randomized (1:1:1:1) to receive: a) a 12-week program of supervised aerobic training (AT), b) AT and low to moderate-intensity strength training, c)AT and moderate to high-intensity strength training, or d) guideline-based physical activity and exercise recommendations. The primary endpoint is 12-week changes in peakVO2. The secondary endpoints are 12-week changes in ChR, 12-week changes in quality of life, and how ChR changes mediate changes in peakVO2. A mixed-effects model for repeated measures will be used to compare endpoint changes. The mean age is 75.1 ± 7.2 years, and most patients are women (57.5 %) in New York Heart Association functional class II (68.7 %). The mean peakVO2, percent of predicted peakVO2, and ChR are 11.8 ± 2.6 mL/kg/min, 67.2 ± 14.7 %, and 0.39 ± 0.16, respectively. No significant baseline clinical differences between arms are found.

CONCLUSIONS

Training-HR will evaluate the effects of different exercise-based therapies on peakVO2, ChR, and quality of life in patients with ChI HFpEF phenotype.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov (NCT05649787).

Macrophage energy metabolism in cardiometabolic disease

In a rapidly expanding body of literature, the major role of energy metabolism in determining the response and polarization status of macrophages has been examined, and it is currently a very active area of research. The metabolic flux through different metabolic pathways in the macrophage is interconnected and complex and could influence the polarization of macrophages. Earlier studies suggested glucose flux through cytosolic glycolysis is a prerequisite to trigger the pro-inflammatory phenotypes of macrophages while proposing that fatty acid oxidation is essential to support anti-inflammatory responses by macrophages. However, recent studies have shown that this understanding is oversimplified and that the metabolic control of macrophage polarization is highly complex and not fully defined yet. In this review, we systematically reviewed and summarized the literature regarding the role of energy metabolism in controlling macrophage activity and how that might be altered in cardiometabolic diseases, namely heart failure, obesity, and diabetes. We critically appraised the experimental studies and methodologies in the published studies. We also highlighted the challenging concepts in macrophage metabolism and identified several research questions yet to be addressed in future investigations.

Association of Systemic Inflammation Level on Admission with Total and Cardiovascular‑Specific Death in Heart Failure with Preserved Ejection Fraction: A Large Multi‑Center Retrospective Longitudinal Study

Purpose

Heart failure with preserved ejection fraction (HFpEF) is inherently a complex inflammatory syndrome, and heightened inflammation is strongly associated with an increased risk of death. However, the association of systemic inflammation levels with total and cardiovascular death among patients with HFpEF remains unknown. We aimed to investigate the prognostic impact of systemic inflammation on all-cause and cardiovascular death among patients with HFpEF.

Patients and Methods

Patients with HFpEF were included in this study. Systemic inflammation response index (SIRI) is defined as the multiplication of neutrophil and monocyte divided by lymphocyte count, and patients were divided into four groups based on SIRI quartiles. Cox regression models and competing risk models were used to examine the relationships between SIRI and total and cardiovascular‑specific mortality, respectively.

Results

9,986 patients with HFpEF were included in five tertiary hospitals. During a median follow-up period of 4.4 years, a total of 2004 patients died, of which 965 were cardiovascular deaths. After fully adjusting for confounders, elevated SIRI level was significantly related to the increased risk of all-cause death (Q2, Q3, Q4: adjusted hazard ratio (aHR) [95 confidence interval (CI)%] =1.17[1.01-1.35], 1.31[1.13-1.52], 1.51[1.30-1.76], respectively; P for trend <0.001). The elevated quartile of SIRI showed higher risks of cardiovascular death, but there was no statistically significant increased risk of cardiovascular death across the lower SIRI quartile (model 3: Q2, Q3, Q4: aHR [95CI%] =1.22[0.99-1.51], 1.50[1.20-1.86], 1.73[1.37-2.18], respectively; P for trend <0.001).

Conclusion

Elevated systemic inflammation level on admission was correlated with an increased risk of all-cause and cardiovascular death among patients with HFpEF. The SIRI may serve as a promising marker of risk stratification for patients with HFpEF.

Heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) accounts for nearly half of all heart failure cases and has a prevalence that is expected to rise with the growing ageing population. HFpEF is associated with significant morbidity and mortality. Specific HFpEF risk factors include age, diabetes, hypertension, obesity and atrial fibrillation. Haemodynamic contributions to HFpEF include changes in left ventricular structure, diastolic and systolic dysfunction, left atrial myopathy, pulmonary hypertension, right ventricular dysfunction, chronotropic incompetence, and vascular dysfunction. Inflammation, fibrosis, impaired nitric oxide signalling, sarcomere dysfunction, and mitochondrial and metabolic defects contribute to the cellular and molecular changes observed in HFpEF. HFpEF impacts multiple organ systems beyond the heart, including the skeletal muscle, peripheral vasculature, lungs, kidneys and brain. The diagnosis of HFpEF can be made in individuals with signs and symptoms of heart failure with abnormality in natriuretic peptide levels or evidence of cardiopulmonary congestion, facilitated by the use of HFpEF risk scores and additional imaging and testing with the exclusion of HFpEF mimics. Management includes initiation of guideline-directed medical therapy and management of comorbidities. Given the significant impact of HFpEF on quality of life, future research efforts should include a particular focus on how patients can live better with this disease.

Clinical Significance of Exercise Pulmonary Hypertension With a Negative Diastolic Stress Test for Suspected Heart Failure With Preserved Ejection Fraction

BACKGROUND

Half of patients with heart failure with preserved ejection fraction (HFpEF) remain undiagnosed by resting evaluation alone. Therefore, exercise testing is proposed. The diastolic stress test (DST), however, has limited sensitivity. We aimed to determine the clinical significance of adding the mean pulmonary artery pressure over cardiac output (mPAP/CO) slope to the DST in suspected HFpEF.

METHODS AND RESULTS

In this prospective cohort study, consecutive patients (n=1936) with suspected HFpEF underwent exercise echocardiography with simultaneous respiratory gas analysis. These patients were stratified by exercise E over e' (exE/e') and mPAP/CO slope, and peak oxygen uptake, natriuretic peptides (NT-proBNP [N-terminal pro-B-type natriuretic peptide]), and score-based HFpEF likelihood were compared. Twenty-two percent of patients (n=428) had exE/e'<15 despite a mPAP/CO slope>3 mm Hg/L per min, 24% (n=464) had a positive DST (exE/e'≥15), and 54% (n=1044) had a normal DST and slope. Percentage of predicted oxygen uptake was similar in the group with exE/e'<15 but high mPAP/CO slope and the positive DST group (-2% [-5% to +1%]), yet worse than in those with normal DST and slope (-12% [-14% to -9%]). Patients with exE/e'<15 but a high slope had NT-proBNP levels and H2FPEF (heavy, hypertensive, atrial fibrillation, pulmonary hypertension, elder; filling pressure) scores intermediate to the positive DST group and the group with both a normal DST and slope.

CONCLUSIONS

Twenty-two percent of patients with suspected HFpEF presented with a mPAP/CO slope>3 mm Hg/L per min despite a negative DST. These patients had HFpEF characteristics and a peak oxygen uptake as low as patients with a positive DST. Therefore, an elevated mPAP/CO slope might indicate HFpEF irrespective of the DST result.

Exercise Stress Echocardiography-Based Phenotyping of Heart Failure With Preserved Ejection Fraction

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome requiring improved phenotypic classification. Previous studies have identified subphenotypes of HFpEF, but the lack of exercise assessment is a major limitation. The aim of this study was to identify distinct pathophysiologic clusters of HFpEF based on clinical characteristics, and resting and exercise assessments.

METHODS

A total of 265 patients with HFpEF underwent ergometry exercise stress echocardiography with simultaneous expired gas analysis. Cluster analysis was performed by the K-prototype method with 21 variables (10 clinical and resting echocardiographic variables and 11 exercise echocardiographic parameters). Pathophysiologic features, exercise tolerance, and prognosis were compared among phenogroups.

RESULTS

Three distinct phenogroups were identified. Phenogroup 1 (n = 112 [42%]) was characterized by preserved biventricular systolic reserve and cardiac output augmentation. Phenogroup 2 (n = 58 [22%]) was characterized by a high prevalence of atrial fibrillation, increased pulmonary arterial and right atrial pressures, depressed right ventricular systolic functional reserve, and impaired right ventricular-pulmonary artery coupling during exercise. Phenogroup 3 (n = 95 [36%]) was characterized by the smallest body mass index, ventricular and vascular stiffening, impaired left ventricular diastolic reserve, and worse exercise capacity. Phenogroups 2 and 3 had higher rates of composite outcomes of all-cause mortality or heart failure events than phenogroup 1 (log-rank P = .02).

CONCLUSION

Exercise echocardiography-based cluster analysis identified three distinct phenogroups of HFpEF, with unique exercise pathophysiologic features, exercise capacity, and clinical outcomes.

Advances in preclinical surgical therapy of cardiovascular diseases

Cardiovascular disease is the most common cause of death worldwide, resulting in millions of deaths annually. Currently, there are still some deficiencies in the treatment of cardiovascular diseases. Innovative surgical treatments are currently being developed and tested in response to this situation. Large animal models, which are similar to humans in terms of anatomy, physiology, and genetics, play a crucial role in connecting basic research and clinical applications. This article reviews recent preclinical studies and the latest clinical advancements in cardiovascular disease based on large animal models, with a focus on targeted delivery, neural regulation, cardiac remodeling, and hemodynamic regulation. It provides new perspectives and ideas for clinical translation and offers new methods for clinical treatment.

Simultaneous Positron Emission Tomography and Molecular Magnetic Resonance Imaging of Cardiopulmonary Fibrosis in a Mouse Model of Left Ventricular Dysfunction

BACKGROUND

Aging-associated left ventricular dysfunction promotes cardiopulmonary fibrogenic remodeling, Group 2 pulmonary hypertension (PH), and right ventricular failure. At the time of diagnosis, cardiac function has declined, and cardiopulmonary fibrosis has often developed. Here, we sought to develop a molecular positron emission tomography (PET)-magnetic resonance imaging (MRI) protocol to detect both cardiopulmonary fibrosis and fibrotic disease activity in a left ventricular dysfunction model.

METHODS AND RESULTS

Left ventricular dysfunction was induced by transverse aortic constriction (TAC) in 6-month-old senescence-accelerated prone mice, a subset of mice that received sham surgery. Three weeks after surgery, mice underwent simultaneous PET-MRI at 4.7 T. Collagen-targeted PET and fibrogenesis magnetic resonance (MR) probes were intravenously administered. PET signal was computed as myocardium- or lung-to-muscle ratio. Percent signal intensity increase and Δ lung-to-muscle ratio were computed from the pre-/postinjection magnetic resonance images. Elevated allysine in the heart (P=0.02) and lungs (P=0.17) of TAC mice corresponded to an increase in myocardial magnetic resonance imaging percent signal intensity increase (P<0.0001) and Δlung-to-muscle ratio (P<0.0001). Hydroxyproline in the heart (P<0.0001) and lungs (P<0.01) were elevated in TAC mice, which corresponded to an increase in heart (myocardium-to-muscle ratio, P=0.02) and lung (lung-to-muscle ratio, P<0.001) PET measurements. Pressure-volume loop and echocardiography demonstrated adverse left ventricular remodeling, function, and increased right ventricular systolic pressure in TAC mice.

CONCLUSIONS

Administration of collagen-targeted PET and allysine-targeted MR probes led to elevated PET-magnetic resonance imaging signals in the myocardium and lungs of TAC mice. The study demonstrates the potential to detect fibrosis and fibrogenesis in cardiopulmonary disease through a dual molecular PET-magnetic resonance imaging protocol.

Microvascular Dysfunction across the Spectrum of Heart Failure Pathology: Pathophysiology, Clinical Features and Therapeutic Implications

Coronary microvascular dysfunction (CMD) plays a crucial role across the spectrum of heart failure (HF) pathology, contributing to disease development, progression, and outcomes. The pathophysiological mechanisms linking CMD to HF are complex and still not completely understood and include chronic inflammation, oxidative stress, and neurohormonal activation. Despite the diagnostic and prognostic relevance in patients with HF, there is no specific therapeutic strategy targeting CMD to date. Moreover, the diagnosis of this clinical condition is challenging. In this review article, we aim to discuss the different clinical pathogenetic mechanisms linking CMD to HF across the different spectra of these diseases, their prognostic relevance, and the possible therapeutic targets along with the remaining knowledge gaps in the field.

Baduanjin for ischemic heart failure with mildly reduced/preserved ejection fraction (BEAR Trial): A randomized controlled trial

AIM

While Baduanjin, a traditional Chinese mind-body exercise, has shown potential health benefits, its efficacy in improving outcomes for heart failure patients with mildly reduced or preserved ejection fraction (HFmrEF/HFpEF) has not been well documented. We aimed to investigate the adjunctive impact of Baduanjin on exercise capacity and quality of life for HFmrEF/HFpEF.

METHODS

Patients with HFmrEF/HFpEF were enrolled in this multicenter randomized clinical trial. All participants were randomized to conventional cardiac rehabilitation with or without an additional 12-week Baduanjin exercise. The primary endpoint was the distance covered in a 6-min walk test (6MWD), while key secondary outcomes included quality of life measured by the Minnesota Living with Heart Failure Questionnaire (MLHFQ) and cardiopulmonary function including anaerobic threshold (VO2 AT).

RESULTS

A total of 120 patients were enrolled, and 109 completed all session and tests. The mean age of the 120 patients was 60.5 years (SD, 9.21 years), and 23 (19.2%) were women. The Baduanjin group exhibited a 6.14% improvement in 6MWD compared to a 1.32% improvement in the control group (median improvement, 25.0 vs. 5.0 m; p < 0.001) at 12th week. The VO2 AT increased by 25.87% in the Baduanjin group versus 3.94% in the control group (p < 0.001). Quality of life also significantly improved in the Baduanjin group as indicated by MLHFQ score changes (-16.8% vs. -3.99%; p < 0.001).

CONCLUSIONS

Adding Baduanjin to exercise-based cardiac rehabilitation for patients with ischemic HFmrEF or HFpEF are generally safe and could provide significant improvements in exercise capacity and quality of life.

Heart Failure With Preserved Ejection Fraction: Will Cardiac Magnetic Imaging Impact on Diagnosis, Treatment, and Outcomes?: Explaining the Need for Advanced Imaging to Clinical Stakeholders

Clinicians frequently equate symptoms of volume overload to heart failure (HF) but such generalization may preclude diagnostic or etiologic precision essential to optimizing outcomes. HF itself must be specified as the disparate types of cardiac pathology have been traditionally surmised by examination of left ventricular (LV) ejection fraction (EF) as either HF with preserved LVEF (HFpEF-LVEF >50%) or reduced LVEF of (HFrEF-LVEF <40%). More recent data support a third, potentially transitional HF subtype, but therapy, assessment, and prognosis have been historically dictated within the corresponding LV metrics determined by echocardiography. The present effort asks whether this historically dominant role of echocardiography is now shifting slightly, becoming instead a shared if not complimentary test. Will there be a gradual increasing profile for cardiac magnetic resonance as the attempt to further refine our understanding, diagnostic accuracy, and outcomes for HFpEF is attempted?

The roles of exercise stress echocardiography for the evaluation of heart failure with preserved ejection fraction in the heart failure pandemic era

Heart failure with preserved ejection fraction (HFpEF) accounts for nearly 70% of all HF and has become the dominant form of HF. The increased prevalence of HFpEF has contributed to a rise in the number of HF patients, known as the "heart failure pandemic". In addition to the fact that HF is a progressive disease and a delayed diagnosis may worsen clinical outcomes, the emergence of disease-modifying treatments such as sodium-glucose transporter 2 inhibitors and glucagon-like peptide-1 receptor agonists has made appropriate and timely identification of HFpEF even more important. However, diagnosis of HFpEF remains challenging in patients with a lower degree of congestion. In addition to normal EF, this is related to the fact that left ventricular (LV) filling pressures are often normal at rest but become abnormal during exercise. Exercise stress echocardiography can identify such exercise-induced elevations in LV filling pressures and facilitate the diagnosis of HFpEF. Exercise stress echocardiography may also be useful for risk stratification and assessment of exercise tolerance as well as cardiovascular responses to exercise. Recent attention has focused on dedicated dyspnea clinics to identify early HFpEF among patients with unexplained dyspnea and to investigate the causes of dyspnea. This review discusses the role of exercise stress echocardiography in the diagnosis and evaluation of HFpEF.

Fractal analysis of left ventricular trabeculae in heart failure with preserved ejection fraction patients with multivessel coronary artery disease

OBJECTIVES

Endocardial trabeculae undergo varicose changes and hyperplasia in response to hemodynamic influences and are a variable phenotype reflecting changes in disease. Fractal analysis has been used to analyze the complexity of endocardial trabeculae in a variety of cardiomyopathies. The aim of this paper was to quantify the myocardial trabecular complexity through fractal analysis and to investigate its predictive value for the diagnosis of heart failure with preserved ejection fraction (HFpEF) in patients with multivessel coronary artery disease (CAD).

METHODS

The retrospective study population consisted of 97 patients with multivessel CAD, 39 of them were diagnosed with HFpEF, while 46 healthy volunteers were recruited as controls. Fractal dimension (FD) was obtained through fractal analysis of endocardial trabeculae on LV short-axis cine images. Logistic regression analyses were used to confirm the predictors and compare different prediction models.

RESULTS

Mean basal FD was significantly higher in patients with HFpEF than in patients without HFpEF or in the healthy group (median: 1.289; IQR: 0.078; p < 0.05). Mean basal FD was also a significant independent predictor in univariate and multivariate logistic regression (OR: 1.107 and 1.043, p < 0.05). Furthermore, adding FD to the prediction model improved the calibration and accuracy of the model (c-index: 0.806).

CONCLUSION

The left ventricular FD obtained with fractal analysis can reflect the complexity of myocardial trabeculae and has an independent predictive value for the diagnosis of HFpEF in patients with multivessel CAD. Including FD into the diagnostic model can help improve the diagnosis.

CRITICAL RELEVANCE STATEMENT

Differences show in the complexity of endocardial trabeculae in multivessel coronary artery disease patients, and obtaining fractal dimensions (FD) by fractal analysis can help identify heart failure with preserved ejection fraction (HFpEF) patients.

KEY POINTS

The complexity of myocardial trabeculae differs among patients with multivessel coronary artery disease. Left ventricular fractal dimensions can reflect the complexity of the myocardial trabecular. Fractal dimensions have predictive value for the diagnosis of heart failure with preserved ejection fraction.

Mixed-type Dyspnoea Diagnosed via Non-invasive and Invasive Cardiopulmonary Exercise Tests

A gas exchange analysis with the cardiopulmonary exercise test is effective in discriminating non-cardiogenic components of limited exercise tolerance and is important for use in combination with the diastolic stress test. An 80-year-old woman with progressive exertional dyspnoea, hypertension, and untreated bronchial asthma was diagnosed with heart failure with a preserved ejection fraction by invasive testing. Diuretics were initiated, which resulted in partial symptom improvement. A subsequent non-invasive test revealed a reduced breathing reserve, suggesting exertional dyspnoea complications linked to lung disease. Bronchodilators were administered, which further improved the symptoms.

Soft robotic platform for progressive and reversible aortic constriction in a small-animal model

Our understanding of cardiac remodeling processes due to left ventricular pressure overload derives largely from animal models of aortic banding. However, these studies fail to enable control over both disease progression and reversal, hindering their clinical relevance. Here, we describe a method for progressive and reversible aortic banding based on an implantable expandable actuator that can be finely tuned to modulate aortic banding and debanding in a rat model. Through catheterization, imaging, and histologic studies, we demonstrate that our platform can recapitulate the hemodynamic and structural changes associated with pressure overload in a controllable manner. We leveraged soft robotics to enable noninvasive aortic debanding, demonstrating that these changes can be partly reversed because of cessation of the biomechanical stimulus. By recapitulating longitudinal disease progression and reversibility, this animal model could elucidate fundamental mechanisms of cardiac remodeling and optimize timing of intervention for pressure overload.

Targeting lymphatic function in cardiovascular-kidney-metabolic syndrome: preclinical methods to analyze lymphatic function and therapeutic opportunities

The lymphatic vascular system spans nearly every organ in the body and serves as an important network that maintains fluid, metabolite, and immune cell homeostasis. Recently, there has been a growing interest in the role of lymphatic biology in chronic disorders outside the realm of lymphatic abnormalities, lymphedema, or oncology, such as cardiovascular-kidney-metabolic syndrome (CKM). We propose that enhancing lymphatic function pharmacologically may be a novel and effective way to improve quality of life in patients with CKM syndrome by engaging multiple pathologies at once throughout the body. Several promising therapeutic targets that enhance lymphatic function have already been reported and may have clinical benefit. However, much remains unclear of the discreet ways the lymphatic vasculature interacts with CKM pathogenesis, and translation of these therapeutic targets to clinical development is challenging. Thus, the field must improve characterization of lymphatic function in preclinical mouse models of CKM syndrome to better understand molecular mechanisms of disease and uncover effective therapies.

The Relationship Between Insulin Resistance Indicated by Triglyceride and Glucose Index and Left Ventricular Hypertrophy and Decreased Left Ventricular Diastolic Function with Preserved Ejection Fraction

Aim

The evidence on the association between insulin resistance (IR) and the prevalence or incidence of cardiac dysfunction has been controversial, and the relationship between pre-diabetic IR and cardiac function is lacking. Large sample studies in the Chinese general population are urgently needed to explore the association between IR and the risk of left ventricular hypertrophy (LVH) and decreased left ventricular diastolic function with preserved ejection fraction (LVDFpEF).

Methods

Based on a National Health Check-up database in China, we conducted a multicenter cross-sectional retrospective study in 344,420 individuals. Furthermore, at a single center, we performed two retrospective longitudinal studies encompassing 8270 and 5827 individuals to investigate the association between IR and the development of new-onset LVH and LVDFpEF, respectively. The median follow-up duration exceeded 2.5 years. The triglyceride and glucose (TyG) index, known for its high sensitivity in detecting IR, serves as a reliable alternative marker of IR. The logistic and cox proportional hazard regression models were used to determine the relationships.

Results

In the cross-sectional study, IR showed a positive association with the prevalence of LVH and decreased LVDFpEF after adjusting for confounders. In the longitudinal cohort, IR was also correlated with the new onset of LVH and decreased LVDFpEF, with hazard ratios (HR) of 1.986 (95% CI: 1.307, 3.017) and 1.386 (95% CI: 1.167, 1.647) in the fourth quartile of TyG levels compared to the lowest quartile, respectively, after adjusting for confounders. The subgroup analysis in non-hypertensive or non-diabetic people and the sensitivity analysis in the population with homeostasis model assessment of insulin resistance (HOMA-IR) further verified the above-mentioned results.

Conclusion

IR was associated with LVH and decreased LVDFpEF. Effective management of IR may prevent or delay the development of adverse LVH and decreased LVDFpEF.

One size does not fit all: Perioperative management of patients with heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is recognized as an important risk factor for perioperative complications. However, anesthesia management of HFpEF patients remains a considerable challenge without clear guidance. HFpEF is heterogeneous in its pathophysiological processes, diverse clinical presentations, adverse remodeling of cardiovascular and other organs, and clinical outcomes. It is difficult to manage the disease with one fixed approach because of this. This review phenotypes HFpEF patients by combining their clinical features and anesthesia care issues. Five phenotypes of HFpEF patients are identified: A, O, P, C, and Y. The clinical features, anesthesia implications, and anesthesia management for each phenotype are highlighted and discussed. Such an approach to HFpEF patients in the operating room could deliver safe, high-quality perioperative care.

Inhibition of activin receptor 2 signalling ameliorates metabolic dysfunction-associated steatotic liver disease in western diet/L-NAME induced cardiometabolic disease

OBJECTIVE

Blockade of activin 2 receptor (ACVR2) signaling has been shown to improve insulin sensitivity and aid in weight loss. Inhibition of ACVR2 signaling restores cardiac function in multiple heart failure models. However, its potential in the treatment of obesity-related cardiometabolic disease remains unknown. Here, we investigated targeting ACVR2 signaling in cardiometabolic disease manifested with metabolic dysfunction-associated steatotic liver disease (MASLD).

METHODS

Mice were fed a high-fat, high-sugar diet combined with the administration of nitric oxide synthase inhibitor L-NAME in drinking water, which causes hypertensive stress. For the last eight weeks, the mice were treated with the soluble ACVR2B decoy receptor (sACVR2B-Fc).

RESULTS

sACVR2B-Fc protected against the development of comorbidities associated with cardiometabolic disease. This was most pronounced in the liver where ACVR2 blockade attenuated the development of MASLD including cessation of pro-fibrotic activation. It also significantly reduced total plasma cholesterol levels, impeded brown adipose tissue whitening, and improved cardiac diastolic function. In vitro, ACVR2 ligands activin A, activin B and GDF11 induced profibrotic signaling and the proliferation of human cardiac fibroblasts.

CONCLUSIONS

Blockade of ACVR2B exerts broad beneficial effects for therapy of cardiometabolic disease. By reducing obesity, ameliorating cardiovascular deterioration and restraining MASLD, blockade of ACVR2B signaling proves a potential target in MASLD and its comorbidities.

Novel insights into the pathobiology of pulmonary hypertension in heart failure with preserved ejection fraction

Heart failure (HF) with preserved ejection fraction (HFpEF) is the most common cause of pulmonary hypertension (PH) worldwide and is strongly associated with adverse clinical outcomes. The American Heart Association recently highlighted a call to action regarding the distinct lack of evidence-based treatments for PH due to poorly understood pathophysiology of PH attributable to HFpEF (PH-HFpEF). Prior studies have described cardiophysiological mechanisms to explain the development of isolated postcapillary PH (ipc-PH); however, the consequent increase in pulmonary vascular (PV) resistance (PVR) may lead to the less understood and more fatal combined pre- and postcapillary PH (cpc-PH). Metabolic disease and inflammatory dysregulation have been suggested to predispose PH, yet the molecular mechanisms are unknown. Although PH-HFpEF has been studied to partly share vasoactive neurohormonal mediators with primary pulmonary arterial hypertension (PAH), clinical trials that have targeted these pathways have been unsuccessful. The increased mortality of patients with PH-HFpEF necessitates further study into viable mechanistic targets involved in disease progression. We aim to summarize the current pathophysiological and clinical understanding of PH-HFpEF, highlight the role of known molecular mechanisms in the progression of PV disease, and introduce a novel concept that lipid metabolism may be attenuating and propagating PH-HFpEF.NEW & NOTEWORTHY Our review addresses pulmonary hypertension (PH) attributable to heart failure (HF) with preserved ejection fraction (HFpEF; PH-HFpEF). Current knowledge gaps in PH-HFpEF pathophysiology have led to a lack of therapeutic targets. Thus, we address identified knowledge gaps in a comprehensive review, focusing on current clinical epidemiology, known pathophysiology, and previously studied molecular mechanisms. We also introduce a comprehensive review of polyunsaturated fatty acid (PUFA) lipid inflammatory mediators in PH-HFpEF.

The pig as an optimal animal model for cardiovascular research

Cardiovascular disease is a worldwide health problem and a leading cause of morbidity and mortality. Preclinical cardiovascular research using animals is needed to explore potential targets and therapeutic options. Compared with rodents, pigs have many advantages, with their anatomy, physiology, metabolism and immune system being more similar to humans. Here we present an overview of the available pig models for cardiovascular diseases, discuss their advantages over other models and propose the concept of standardized models to improve translation to the clinical setting and control research costs.

Prognostic Value of a Multi-mRNA Signature for 1-Year All-Cause Death in Hospitalized Patients With Heart Failure With a Preserved Ejection Fraction

BACKGROUND

Heart failure with preserved ejection fraction is a major global public health problem, while effective risk stratification tools are still lacking. We sought to construct a multi-mRNA signature to predict 1-year all-cause death.

METHODS

We selected 30 patients with heart failure with preserved ejection fraction who died during 1-year follow-up and 30 who survived in the discovery set. One hundred seventy-one and 120 patients with heart failure with preserved ejection fraction were randomly selected as a test set and a validation set, respectively. We performed mRNA microarrays in all patients.

RESULTS

We constructed a 5-mRNA signature for predicting 1-year all-cause death. The scores of the 5-mRNA signature were significantly associated with the 1-year risk of all-cause death in both the test set (hazard ratio, 2.72 [95% CI, 1.98-3.74]; P<0.001) and the validation set (hazard ratio, 3.95 [95% CI, 2.40-6.48]; P<0.001). Compared with a reference model, which included sex, ASCEND-HF (Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure) score, history of HF and NT-proBNP (N-terminal pro-B-type natriuretic peptide), the 5-mRNA signature had a better discrimination capability, with an increased area under the curve from 0.696 to 0.813 in the test set and from 0.712 to 0.848 in the validation set. A composite model integrating the 5-mRNA risk score and variables in the reference model demonstrated an excellent discrimination capability, with an area under the curve of 0.861 (95% CI, 0.784-0.939) in the test set and an area under the curve of 0.859 (95% CI, 0.755-0.963) in the validation set. The net reclassification improvement and integrated discrimination improvement indicated that the composite model significantly improved patient classification compared with the reference model in both sets (P<0.001).

CONCLUSIONS

The 5-mRNA signature is a promising predictive tool for 1-year all-cause death and shows improved prognostic power over the established risk scores and NT-proBNP in patients with heart failure with preserved ejection fraction.

Clinical characteristics and prognosis of patients with hypertrophic cardiomyopathy and heart failure with preserved ejection fraction

BACKGROUND

Whether heart failure with preserved ejection fraction (HFpEF) is associated with an increased risk of developing systolic dysfunction and a poor prognosis in hypertrophic cardiomyopathy (HCM) patients is unknown.

OBJECTIVE

We aimed to assess risk factors for the development of end-stage (ES) heart failure (HF) (ejection fraction < 50%) and compare the prognosis of different HF phenotypes.

METHODS

This retrospective study was conducted on patients with HCM in China between January 2009 and February 2023. Patients were stratified into three different groups: HCM-non-HF, HCM-HFpEF and HCM-heart failure with reduced ejection fraction (HCM-HFrEF). The primary outcome was a composite of major adverse cardiac events (MACEs), including all-cause deaths, HF hospitalization, sudden cardiac death and ventricular tachycardia.

RESULTS

Of 3,620 HCM patients enrolled, 1,553 (42.9%) had non-HF, 1,666 (46.0%) had HFpEF, and 579 patients (11.1%) had HFrEF at baseline. During the median follow-up period of 4.0 years (IQR 1.4-9.4 years), patients with HCM-HFpEF exhibited a higher incidence of ES-HF than those with HCM-non-HF (12.4% vs. 2.7%, P < 0.001). HFpEF was an independent risk factor for ES-HF development (HR 3.84, 2.54-5.80, P < 0.001). MACEs occurred in 26.9% with a higher incidence in HCM-HFpEF than HCM-non-HF (36.6% vs 12.2%, P < 0.001). HFpEF was an independent predictor of MACEs (HR 2.13, 1.75-2.59, P < 0.001).

CONCLUSIONS

HFpEF is common in HCM. Compared to non-HF, it increases the risk of LVEF decline and poor prognosis. It may aid in risk stratification and need close echocardiography follow-up.

Artificial Intelligence and Its Role in Diagnosing Heart Failure: A Narrative Review

Heart failure (HF) is prevalent globally. It is a dynamic disease with varying definitions and classifications due to multiple pathophysiologies and etiologies. The diagnosis, clinical staging, and treatment of HF become complex and subjective, impacting patient prognosis and mortality. Technological advancements, like artificial intelligence (AI), have been significant roleplays in medicine and are increasingly used in cardiovascular medicine to transform drug discovery, clinical care, risk prediction, diagnosis, and treatment. Medical and surgical interventions specific to HF patients rely significantly on early identification of HF. Hospitalization and treatment costs for HF are high, with readmissions increasing the burden. AI can help improve diagnostic accuracy by recognizing patterns and using them in multiple areas of HF management. AI has shown promise in offering early detection and precise diagnoses with the help of ECG analysis, advanced cardiac imaging, leveraging biomarkers, and cardiopulmonary stress testing. However, its challenges include data access, model interpretability, ethical concerns, and generalizability across diverse populations. Despite these ongoing efforts to refine AI models, it suggests a promising future for HF diagnosis. After applying exclusion and inclusion criteria, we searched for data available on PubMed, Google Scholar, and the Cochrane Library and found 150 relevant papers. This review focuses on AI's significant contribution to HF diagnosis in recent years, drastically altering HF treatment and outcomes.

Elevated ITGA1 levels in type 2 diabetes: implications for cardiac function impairment

AIMS/HYPOTHESIS

Type 2 diabetes mellitus is known to contribute to the development of heart failure with preserved ejection fraction (HFpEF). However, identifying HFpEF in individuals with type 2 diabetes early on is often challenging due to a limited array of biomarkers. This study aims to investigate specific biomarkers associated with the progression of HFpEF in individuals with type 2 diabetes, for the purpose of enabling early detection and more effective management strategies.

METHODS

Blood samples were collected from individuals with type 2 diabetes, both with and without HFpEF, for proteomic analysis. Plasma integrin α1 (ITGA1) levels were measured and compared between the two groups. Participants were further categorised based on ITGA1 levels and underwent detailed transthoracic echocardiography at baseline and during a median follow-up period of 30 months. Multivariable linear and Cox regression analyses were conducted separately to assess the associations between plasma ITGA1 levels and changes in echocardiography indicators and re-hospitalisation risk. Additionally, proteomic data for the individuals' left ventricles, from ProteomeXchange database, were analysed to uncover mechanisms underlying the change in ITGA1 levels in HFpEF.

RESULTS

Individuals with type 2 diabetes and HFpEF showed significantly higher plasma ITGA1 levels than the individuals with type 2 diabetes without HFpEF. These elevated ITGA1 levels were associated with left ventricular remodelling and impaired diastolic function. Furthermore, during a median follow-up of 30 months, multivariable analysis revealed that elevated ITGA1 levels independently correlated with deterioration of both diastolic and systolic cardiac functions. Additionally, higher baseline plasma ITGA1 levels independently predicted re-hospitalisation risk (HR 2.331 [95% CI 1.387, 3.917], p=0.001). Proteomic analysis of left ventricular myocardial tissue provided insights into the impact of increased ITGA1 levels on cardiac fibrosis-related pathways and the contribution made by these changes to the development and progression of HFpEF.

CONCLUSIONS/INTERPRETATION

ITGA1 serves as a biomarker for monitoring cardiac structural and functional damage, can be used to accurately diagnose the presence of HFpEF, and can be used to predict potential deterioration in cardiac structure and function as well as re-hospitalisation for individuals with type 2 diabetes. Its measurement holds promise for facilitating risk stratification and early intervention to mitigate the adverse cardiovascular effects associated with diabetes.

DATA AVAILABILITY

The proteomic data of left ventricular myocardial tissue from individuals with type 2 diabetes, encompassing both those with and without HFpEF, is available from the ProteomeXchange database at http://proteomecentral.proteomexchange.org .

Benefits of Puerarin on Metabolic Syndrome and Its Associated Cardiovascular Diseases in Rats Fed a High-Fat/High-Sucrose Diet

Metabolic syndrome (MetS) is a cluster of risk factors for cardiovascular diseases (CVDs) that has become a global public health problem. Puerarin (PUE), the principal active compound of Pueraria lobata, has the effects of regulating glucose and lipid metabolism and protecting against cardiovascular damage. This study aimed to investigate whether dietary supplementation with PUE could ameliorate MetS and its associated cardiovascular damage. Rats were randomly divided into three groups: the normal diet group (NC), the high-fat/high-sucrose diet group (HFHS), and the HFHS plus PUE diet group (HFHS-PUE). The results showed that PUE-supplemented rats exhibited enhanced glucose tolerance, improved lipid parameters, and reduced blood pressure compared to those on the HFHS diet alone. Additionally, PUE reversed the HFHS-induced elevations in the atherogenic index (AI) and the activities of serum lactate dehydrogenase (LDH) and creatine kinase (CK). Ultrasonic evaluations indicated that PUE significantly ameliorated cardiac dysfunction and arterial stiffness. Histopathological assessments further confirmed that PUE significantly mitigated cardiac remodeling, arterial remodeling, and neuronal damage in the brain. Moreover, PUE lowered systemic inflammatory indices including C-reactive protein (CRP), neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and systemic immune-inflammation index (SII). In conclusion, dietary supplementation with PUE effectively moderated metabolic disorders, attenuated systemic inflammation, and minimized cardiovascular damage in rats with MetS induced by an HFHS diet. These results provide novel insights into the potential benefits of dietary PUE supplementation for the prevention and management of MetS and its related CVDs.

Semaglutide in Patients with Obesity-Related Heart Failure and Type 2 Diabetes

BACKGROUND

Obesity and type 2 diabetes are prevalent in patients with heart failure with preserved ejection fraction and are characterized by a high symptom burden. No approved therapies specifically target obesity-related heart failure with preserved ejection fraction in persons with type 2 diabetes.

METHODS

We randomly assigned patients who had heart failure with preserved ejection fraction, a body-mass index (the weight in kilograms divided by the square of the height in meters) of 30 or more, and type 2 diabetes to receive once-weekly semaglutide (2.4 mg) or placebo for 52 weeks. The primary end points were the change from baseline in the Kansas City Cardiomyopathy Questionnaire clinical summary score (KCCQ-CSS; scores range from 0 to 100, with higher scores indicating fewer symptoms and physical limitations) and the change in body weight. Confirmatory secondary end points included the change in 6-minute walk distance; a hierarchical composite end point that included death, heart failure events, and differences in the change in the KCCQ-CSS and 6-minute walk distance; and the change in the C-reactive protein (CRP) level.

RESULTS

A total of 616 participants underwent randomization. The mean change in the KCCQ-CSS was 13.7 points with semaglutide and 6.4 points with placebo (estimated difference, 7.3 points; 95% confidence interval [CI], 4.1 to 10.4; P<0.001), and the mean percentage change in body weight was -9.8% with semaglutide and -3.4% with placebo (estimated difference, -6.4 percentage points; 95% CI, -7.6 to -5.2; P<0.001). The results for the confirmatory secondary end points favored semaglutide over placebo (estimated between-group difference in change in 6-minute walk distance, 14.3 m [95% CI, 3.7 to 24.9; P = 0.008]; win ratio for hierarchical composite end point, 1.58 [95% CI, 1.29 to 1.94; P<0.001]; and estimated treatment ratio for change in CRP level, 0.67 [95% CI, 0.55 to 0.80; P<0.001]). Serious adverse events were reported in 55 participants (17.7%) in the semaglutide group and 88 (28.8%) in the placebo group.

CONCLUSIONS

Among patients with obesity-related heart failure with preserved ejection fraction and type 2 diabetes, semaglutide led to larger reductions in heart failure-related symptoms and physical limitations and greater weight loss than placebo at 1 year. (Funded by Novo Nordisk; STEP-HFpEF DM ClinicalTrials.gov number, NCT04916470.).

B-Type Natriuretic Peptide-A Paradox in the Diagnosis of Acute Heart Failure with Preserved Ejection Fraction in Obese Patients

BACKGROUND AND OBJECTIVES

B-type natriuretic peptide (BNP) represents a clinical tool for the diagnosis and prognostic evaluation of acute and chronic heart failure patients. The purpose of this retrospective study was to evaluate BNP values in obese and non-obese patients with acute heart failure with preserved ejection fraction.

MATERIALS AND METHODS

In this study, we enrolled 240 patients who presented to the emergency department complaining of acute shortness of breath and fatigue. The patients were divided into two groups according to their body mass index (BMI) values. The BMI was calculated as weight (kilograms) divided by height (square meters). The BNP testing was carried out in the emergency department.

RESULTS

Group I included patients with a BMI of <30 kg/m2 and group II included patients with a BMI of ≥30 kg/m2. The average age of the patients was 60.05 ± 5.02 years. The patients in group II were significantly younger compared with those included in group I. Group II included a higher number of women compared to group I. Group I had fewer patients classified within New York Heart Association (NYHA) functional classes III and IV compared with group II. Echocardiography revealed an ejection fraction of ≥50% in all participants. Lower BNP levels were observed in patients from group II (median = 56, IQR = 53-67) in comparison to group I (median = 108.5, IQR = 106-112) (p < 0.001).

CONCLUSIONS

Obesity and heart failure are continuously rising worldwide. In this retrospective study, we have highlighted the necessity to lower the threshold of BNP levels in obese patients with acute heart failure and preserved ejection fraction.

Clinical Trajectory and Risk Stratification for Heart Failure with Preserved Ejection Fraction in a Real-World Cohort of Patients with Suspected Coronary Artery Disease

Background: Heart failure with preserved ejection fraction (HFpEF) is a widespread condition with significant morbidity and mortality. Its clinical heterogeneity may delay the diagnosis. Aim: To identify predictors of HFpEF-related hospitalizations in ambulatory patients presenting with elevated cardiovascular risk, suspected coronary artery diseases (CADs), and positive HFpEF screenings. Methods: Consecutive patients presenting with suspected CAD, enrolled in the observational LIFE-Heart study (2006-2014, NCT00497887), and meeting HFpEF criteria per the 2016 European Society of Cardiology (ESC) guidelines were categorized according to the presence of "overlapping conditions" potentially masking or contributing to their symptoms. Additional stratification using the H2FPEF score (<2: low risk, 2-5: intermediate risk, and ≥6 high risk) was performed. Follow-up for hospitalizations, reasons of hospitalization, and death spanned a median of 6 years. Results: Of 1054 patients (66 ± 10 years, 60% male, NT-pro-BNP 286, IQR 183-574 pg/mL), 53% had overlapping conditions, while 47% had "isolated HFpEF". The H2FPEF scores classified 23%, 57%, and 20% as low-, intermediate-, and high-risk, respectively, with consistent proportions across patients with and without overlapping conditions (p = 0.91). During the follow-up observational phase, 54% were rehospitalized, 22% experienced heart failure (HF) rehospitalizations, and 11% of patients died. Multivariable logistic regression revealed a high-risk H2FPEF category as an independent predictor of HF rehospitalization in the overall cohort (odds ratio: 3.4, CI: 2.4-4.9, p < 0.01) as well as in patients with and without overlapping conditions. Furthermore, a H2FPEF score ≥ 6 was independently associated with higher mortality rates (hazard ratio: 1.8, CI: 1.2-2.6, p < 0.01) in the Cox regression analysis. Conclusions: Ambulatory patients presenting for suspected CAD and meeting HFpEF screening criteria face elevated risks for rehospitalizations over six years. Regardless of concomitant diagnoses, quantifying cardiac damage with the H2FPEF score helps in risk-stratifying patients for HF hospitalization and mortality.

HBI-8000 improves heart failure with preserved ejection fraction via the TGF-β1/MAPK signalling pathway

Heart failure with preserved ejection fraction (HFpEF) accounts for approximately 50% of total heart failure patients and is characterized by peripheral circulation, cardiac remodelling and comorbidities (such as advanced age, obesity, hypertension and diabetes) with limited treatment options. Chidamide (HBI-8000) is a domestically produced benzamide-based histone deacetylase isoform-selective inhibitor used for the treatment of relapsed refractory peripheral T-cell lymphomas. Based on our in vivo studies, we propose that HBI-8000 exerts its therapeutic effects by inhibiting myocardial fibrosis and myocardial hypertrophy in HFpEF patients. At the cellular level, we found that HBI-8000 inhibits AngII-induced proliferation and activation of CFs and downregulates the expression of fibrosis-related factors. In addition, we observed that the HFpEF group and AngII stimulation significantly increased the expression of TGF-β1 as well as phosphorylated p38MAPK, JNK and ERK, whereas the expression of the above factors was significantly reduced after HBI-8000 treatment. Activation of the TGF-β1/MAPK pathway promotes the development of fibrotic remodelling, and pretreatment with SB203580 (p38MAPK inhibitor) reverses this pathological change. In conclusion, our data suggest that HBI-8000 inhibits fibrosis by modulating the TGF-β1/MAPK pathway thereby improving HFpEF. Therefore, HBI-8000 may become a new hope for the treatment of HFpEF patients.

Classification, Diagnosis, and Treatment of Obesity-Related Heart Diseases

Evidence-based medicine shows that obesity is associated with a wide range of cardiovascular (CV) diseases. Obesity can lead to changes in cardiac structure and function, which can lead to obese cardiomyopathy, subclinical cardiac dysfunction, and even heart failure. It also increases the risk of atrial fibrillation and sudden cardiac death. Many invasive and noninvasive diagnostic methods can detect obesity-related heart disease at an early stage, so that appropriate measures can be selected to prevent adverse CV events. However, studies have shown a protective effect of obesity on clinical outcomes of CV disease, a phenomenon that has been termed the obesity paradox. The "obesity paradox" essentially refers to the fact that the classification of obesity defined by body mass index (BMI) does not consider the impact of obesity heterogeneity on CV disease prognosis, but simply puts subjects with different clinical and biochemical characteristics into the same category. In any case, indicators such as waist-to-hip ratio, ectopic body fat qualitative and quantitative, and CV fitness have been shown to be able to distinguish different CV risks in patients with the same BMI, which is convenient for early intervention in an appropriate way. A multidisciplinary approach, including lifestyle modification, evidence-based generic and novel pharmacotherapy, and surgical intervention, can improve CV outcomes in overweight/obese patients.

Left atrial cardiomyopathy: Pathophysiological insights, assessment methods and clinical implications

Atrial cardiomyopathy is defined as any complex of structural, architectural, contractile or electrophysiological changes affecting atria, with the potential to produce clinically relevant manifestations. Most of our knowledge about the mechanistic aspects of atrial cardiomyopathy is derived from studies investigating animal models of atrial fibrillation and atrial tissue samples obtained from individuals who have a history of atrial fibrillation. Several noninvasive tools have been reported to characterize atrial cardiomyopathy in patients, which may be relevant for predicting the risk of incident atrial fibrillation and its related outcomes, such as stroke. Here, we provide an overview of the pathophysiological mechanisms involved in atrial cardiomyopathy, and discuss the complex interplay of these mechanisms, including aging, left atrial pressure overload, metabolic disorders and genetic factors. We discuss clinical tools currently available to characterize atrial cardiomyopathy, including electrocardiograms, cardiac imaging and serum biomarkers. Finally, we discuss the clinical impact of atrial cardiomyopathy, and its potential role for predicting atrial fibrillation, stroke, heart failure and dementia. Overall, this review aims to highlight the critical need for a clinically relevant definition of atrial cardiomyopathy to improve treatment strategies.

Prognostic Significance of Elevated Left Ventricular Filling Pressures with Exercise: Insights from a Cohort of 14,338 Patients

BACKGROUND

Exercise echocardiography can assess for cardiovascular causes of dyspnea other than coronary artery disease. However, the prevalence and prognostic significance of elevated left ventricular (LV) filling pressures with exercise is understudied.

METHODS

We evaluated 14,338 patients referred for maximal symptom-limited treadmill echocardiography. In addition to assessment of LV regional wall motion abnormalities (RWMAs), we measured patients' early diastolic mitral inflow (E), septal mitral annulus relaxation (e'), and peak tricuspid regurgitation velocity before and immediately after exercise.

RESULTS

Over a mean follow-up of 3.3 ± 3.4 years, patients with E/e' ≥15 with exercise (n = 1,323; 9.2%) had lower exercise capacity (7.3 ± 2.1 vs 9.1 ± 2.4 metabolic equivalents, P < .0001) and were more likely to have resting or inducible RWMAs (38% vs 18%, P < .0001). Approximately 6% (n = 837) had elevated LV filling pressures without RWMAs. Patients with a poststress E/e' ≥15 had a 2.71-fold increased mortality rate (2.28-3.21, P < .0001) compared with those with poststress E/e' ≤ 8. Those with an E/e' of 9 to 14, while at lower risk than the E/e' ≥15 cohort (hazard ratio [HR] = 0.58 [0.48-0.69]; P < .0001), had higher risk than if E/e' ≤8 (HR = 1.56 [1.37-1.78], P < .0001). On multivariable analysis, adjusting for age, sex, exercise capacity, LV ejection fraction, and presence of pulmonary hypertension with stress, patients with E/e' ≥15 had a 1.39-fold (95% CI, 1.18-1.65, P < .0001) increased risk of all-cause mortality compared with patients without elevated LV filling pressures. Compared with patients with E/e' ≤ 15 after exercise, patients with E/e' ≤15 at rest but elevated after exercise had a higher risk of cardiovascular death (HR = 8.99 [4.7-17.3], P < .0001).

CONCLUSION

Patients with elevated LV filling pressures are at increased risk of death, irrespective of myocardial ischemia or LV systolic dysfunction. These findings support the routine incorporation of LV filling pressure assessment, both before and immediately following stress, into the evaluation of patients referred for exercise echocardiography.

Silencing of METTL3 suppressed ferroptosis of myocardial cells by m6A modification of SLC7A11 in a YTHDF2 manner

Myocardial infarction (MI) is the main cause of heart failure (HF). N6-methyladenosine (m6A) methylation is associated with the progression of HF. The study aimed to explore whether METTL3 regulates ferroptosis of cardiomyocytes in HF. We evaluated ferroptosis by detecting lactic dehydrogenase (LDH) release, lipid reactive oxygen species (ROS), Fe2+, glutathione (GSH), and malonaldehyde (MDA) levels. M6A methylation was assessed using methylated RNA immunoprecipitation assay. The binding relationship was assessed using RNA immunoprecipitation assays. The mRNA stability was assessed using actinomycin D treatment. The results showed that METTL3 was upregulated in oxygen glucose deprivation/recovery (OGD/R) cells, which knockdown suppressed OGD/R-induced ferroptosis. Moreover, METTL3 could bind to SLC7A11, promoting m6A methylation of SLC7A11. Silencing of SLC7A11 abrogated the suppression of ferroptosis induced by METTL3 knockdown. Additionally, YTHDF2 was the reader that recognized the methylation of SLC7A11, reducing the stability of SLC7A11. The silencing of METTL3 inhibited OGD/R-induced ferroptosis by suppressing the m6A methylation of SLC7A11, which is recognized by YTHDF2. The findings suggested that METTL3-mediated ferroptosis might be a new strategy for MI-induced HF therapy.

Association of hypertension burden with stroke risk in patients with heart failure with preserved ejection fraction

Introduction

Whether the hypertension burden is associated with stroke incidence is inconclusive. In this study, we aimed to investigate the relationship between hypertension burden and stroke risk in patients with heart failure with preserved ejection fraction (HFpEF).

Methods

HFpEF patients from the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) trial were divided into three groups (low, medium, and high risk) according to their hypertension burden values. Higher hypertension burden risk represented the longer duration of hypertension. We evaluated the association of hypertension burden with stroke risk using Fine and Gray's competing risk models.

Results

A total of 3431 HFpEF patients (mean age: 68.5 ± 9.58 years, 51.6% females) were enrolled. During a median follow-up of 3.3 years, per 10-point increase in hypertension burden was associated with any stroke (hazard ratio [HR] 1.15, 95% confidence interval [CI] 1.08-1.21), new-onset stroke (HR 1.14, 95% CI 1.07-1.21), and ischemic stroke (HR 1.10, 95% CI 1.02-1.17). When hypertension burden was analyzed as a categorical variable, any stroke risk was increased in the medium- (HR 1.59, 95% CI 1.01-2.40) and high-risk (HR 3.19, 95% CI 2.05-4.97) groups when compared with the low-risk group. For the outcomes of new-onset (HR 2.92, 95% CI 1.80-4.74) and ischemic stroke (HR 2.46, 95% CI 1.41-4.29), similar results were observed in patients with high-versus low-risk hypertension burden.

Conclusions

Increasing hypertension burden was associated with an increased risk of stroke, suggesting that shortening hypertension duration might appropriately minimize the stroke incidence in HFpEF patients.

Informing understanding of coordination of care for patients with heart failure with preserved ejection fraction: a secondary qualitative analysis

BACKGROUND

Patients with heart failure with preserved ejection fraction (HFpEF) are a complex and underserved group. They are commonly older patients with multiple comorbidities, who rely on multiple healthcare services. Regional variation in services and resourcing has been highlighted as a problem in heart failure care, with few teams bridging the interface between the community and secondary care. These reports conflict with policy goals to improve coordination of care and dissolve boundaries between specialist services and the community.

AIM

To explore how care is coordinated for patients with HFpEF, with a focus on the interface between primary care and specialist services in England.

METHODS

We applied systems thinking methodology to examine the relationship between work-as-imagined and work-as-done for coordination of care for patients with HFpEF. We analysed clinical guidelines in conjunction with a secondary applied thematic analysis of semistructured interviews with healthcare professionals caring for patients with HFpEF including general practitioners, specialist nurses and cardiologists and patients with HFpEF themselves (n=41). Systems Thinking for Everyday Work principles provided a sensitising theoretical framework to facilitate a deeper understanding of how these data illustrate a complex health system and where opportunities for improvement interventions may lie.

RESULTS

Three themes (working with complexity, information transfer and working relationships) were identified to explain variability between work-as-imagined and work-as-done. Participants raised educational needs, challenging work conditions, issues with information transfer systems and organisational structures poorly aligned with patient needs.

CONCLUSIONS

There are multiple challenges that affect coordination of care for patients with HFpEF. Findings from this study illuminate the complexity in coordination of care practices and have implications for future interventional work.

HFpEF as systemic disease, insight from a diagnostic prediction model reminiscent of systemic inflammation and organ interaction in HFpEF patients

Systemic inflammation and reciprocal organ interactions are associated with the pathophysiology of heart failure with preserved ejection fraction (HFpEF). However, the clinical value, especially the diagnositc prediction power of inflammation and extra-cardiac organ dysfunction for HfpEF is not explored. In this cross-sectional study, 1808 hospitalized patients from January 2014 to June 2022 in ChiHFpEF cohort were totally enrolled according to inclusion and exclusion criteria. A diagnostic model with markers from routine blood test as well as liver and renal dysfunction for HFpEF was developed using data from ChiHFpEF-cohort by logistic regression and assessed by receiver operating characteristic curve (ROC) and Brier score. Then, the model was validated by the tenfold cross-validation and presented as nomogram and a web-based online risk calculator as well. Multivariate and LASSO regression analysis revealed that age, hemoglobin, neutrophil to lymphocyte ratio, AST/ALT ratio, creatinine, uric acid, atrial fibrillation, and pulmonary hypertension were associated with HFpEF. The predictive model exhibited reasonably accurate discrimination (ROC, 0.753, 95% CI 0.732-0.772) and calibration (Brier score was 0.200). Subsequent internal validation showed good discrimination and calibration (AUC = 0.750, Brier score was 0.202). In additoin to participating in pathophysiology of HFpEF, inflammation and multi-organ interactions have diagnostic prediction value for HFpEF. Screening and optimizing biomarkers of inflammation and multi-organ interactions stand for a new field to improve noninvasive diagnostic tool for HFpEF.

The prevalence of coronary microvascular dysfunction (CMD) in heart failure with preserved ejection fraction (HFpEF): a systematic review and meta-analysis

To date, studies on the prevalence of coronary microvascular dysfunction (CMD) in heart failure with preserved ejection fraction (HFpEF) have not been summarized and analyzed as a whole. We conducted this systematic review and meta-analysis to assess the prevalence of CMD in patients with HFpEF. The PubMed, Cochrane, and Embase databases were searched from dates of inception until May 1, 2023. The primary outcome was the prevalence of CMD in patients with HFpEF, and values of CMD prevalence were pooled using a random-effects model. In total, 10 studies involving 1267 patients, including 822 with HFpEF and 445 without HFpEF, were included. The pooled prevalence of CMD in patients with HFpEF was 71% (95% CI, 0.63-0.79). In the subgroup analysis, the prevalence of CMD was 79% (95% CI, 0.71-0.87) by invasive measurement and 66% (95% CI, 0.54-0.77) by noninvasive measurement and 67% (95% CI, 0.52-0.82) with CFR < 2.0 and 75.0% (95% CI, 0.71-0.79) with CFR < 2.5. The prevalence of endothelium-independent CMD and endothelium-dependent CMD was 62% (95% CI, 0.53-0.72) and 50% (95% CI, 0.19-0.81), respectively. The prevalence of CMD was 74% (95% CI = 0.69-0.79) and 66% (95% CI = 0.41-0.90) in prospective and retrospective studies, respectively. Compared with the control group, patients with HFpEF had a significantly lower CFR (MD =  - 1.28, 95% CI =  - 1.82 to - 0.74, P < 0.01) and a higher prevalence of CMD (RR = 2.21, 95% CI = 1.52 to 3.20, P < 0.01). Qualitative analysis demonstrated that CMD might be associated with poor clinical outcomes in patients with HFpEF. In conclusion, this is the first systematic review and meta-analysis of all studies reporting the prevalence of CMD in patients with HFpEF. Our study demonstrates that CMD is common in patients with HFpEF and might be associated with poor clinical outcomes in these patients. Clinicians should attach importance to CMD in the diagnosis and treatment of HFpEF. The number of studies in this field is relatively small. Therefore, more high-quality studies are needed to explore the diagnostic and prognostic value of CMD and the potential role of CMD as a therapeutic target in patients with HFpEF.

Volume and function changes of left atrium and left ventricle in patients with ejection fraction preserved heart failure measured by a three dimensional dynamic heart model

The accurate diagnosis of HFpEF is still challenging and controversial. In this study, we used 3D-DHM technology to compare the differences of cardiac structure and function between HFpEF patients and healthy controls, as well as the differences of two-dimensional and three-dimensional cardiac function in HFpEF patients. Echocardiography with 3D-DHM and conventional two-dimensional (2D) methods were applied to measure the volume and function parameters of left atrium and ventricle of patients with HFpEF and healthy controls. Significant differences of 3D cardiac function indexes including LVESV, 3D-LVEF, ESL, SV, CI, EDmass, LAVmax, LAVmin, LAEF, and LAVI were observed between patients with HFpEF and controls (P < 0.05). However, no significant difference of LVEDV and EDL were observed (P > 0.05). In addition, we found no significant between-group difference in 2D cardiac function indexes such as LVDD and 2D-LVEF (P > 0.05), but the LAD, LVSD, LVPW, IVS, E, E/A, and E/e ' were significantly different between groups (P < 0.05). There was no significant difference between 3D-LVEF and 2D-LVEF in the control group (P > 0.05), while 3D-LVEF in the HFpEF group was lower than 2D-LVEF(P < 0.05). Among the two-dimensional and three-dimensional parameters of HFpEF patients, the parameters related to diastolic function changed more significantly than those of the normal group, and the three-dimensional LVEF of HFpEF patients decreased. The three-dimensional cardiac function parameters analyzed by DHM can provide more information regarding myocardial mechanics.

Noncardiovascular morbidity and mortality across left ventricular ejection fraction categories following hospitalization for heart failure

INTRODUCTION AND OBJECTIVES

Noncardiovascular events represent a significant proportion of the morbidity and mortality burden in patients with heart failure (HF). However, the risk of these events appears to differ by left ventricular ejection fraction (LVEF) status. In this study, we sought to evaluate the risk of noncardiovascular death and recurrent noncardiovascular readmission by LVEF status following an admission for acute HF.

METHODS

We retrospectively assessed a cohort of 4595 patients discharged after acute HF in a multicenter registry. We evaluated LVEF as a continuum, stratified in 4 categories (LVEF ≤ 40%, 41%-49%, 50%-59%, and ≥ 60%). Study endpoints were the risks of noncardiovascular mortality and recurrent noncardiovascular admissions during follow-up.

RESULTS

At a median follow-up of 2.2 [interquartile range, 0.76-4.8] years, we registered 646 noncardiovascular deaths and 4014 noncardiovascular readmissions. After multivariable adjustment including cardiovascular events as a competing event, LVEF status was associated with the risk of noncardiovascular mortality and recurrent noncardiovascular admissions. When compared with patients with LVEF ≤ 40%, those with LVEF 51%-59%, and especially those with LVEF ≥ 60%, were at higher risk of noncardiovascular mortality (HR, 1.31; 95%CI, 1.02-1,68; P=.032; and HR, 1.47; 95%CI, 1.15-1.86; P=.002; respectively), and at higher risk of recurrent noncardiovascular admissions (IRR, 1.17; 95%CI, 1.02-1.35; P=.024; and IRR, 1.26; 95%CI, 1.11-1.45; P=.001; respectively).

CONCLUSIONS

Following an admission for HF, LVEF status was directly associated with the risk of noncardiovascular morbidity and mortality. Patients with HFpEF were at higher risk of noncardiovascular death and total noncardiovascular readmissions, especially those with LVEF ≥ 60%.

Impact of ovary-intact menopause in a mouse model of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) afflicts over half of all patients with heart failure and is a debilitating and fatal syndrome affecting postmenopausal women more than any other demographic. This bias toward older females calls into question the significance of menopause in the development of HFpEF, but this question has not been probed in detail. In this study, we report the first investigation into the impact of ovary-intact menopause in the context of HFpEF. To replicate the human condition as faithfully as possible, vinylcyclohexene dioxide (VCD) was used to accelerate ovarian failure (AOF) in female mice while leaving the ovaries intact. HFpEF was established with a mouse model that involves two stressors typical in humans: a high-fat diet and hypertension induced from the nitric oxide synthase inhibitor NG-nitro-l-arginine methyl ester (l-NAME). In young female mice, AOF or HFpEF-associated stressors independently induced abnormal myocardial strain indicative of early subclinical systolic and diastolic cardiac dysfunction. HFpEF but not AOF was associated with elevations in systolic blood pressure. Increased myocyte size and reduced myocardial microvascular density were not observed in any group. Also, a broad panel of measurements that included echocardiography, invasive pressure measurements, histology, and serum hormones revealed no interaction between AOF and HFpEF. Interestingly, AOF did evoke a higher density of infiltrating cardiac immune cells in both healthy and HFpEF mice, suggestive of proinflammatory effects. In contrast to young mice, middle-aged "old" mice did not exhibit cardiac dysfunction from estrogen deprivation alone or from HFpEF-related stressors.NEW & NOTEWORTHY This is the first preclinical study to examine the impact of ovary-intact menopause [accelerated ovarian failure (AOF)] on HFpEF. Echocardiography of young female mice revealed early evidence of diastolic and systolic cardiac dysfunction apparent only on strain imaging in HFpEF only, AOF only, or the combination. Surprisingly, AOF did not exacerbate the HFpEF phenotype. Results in middle-aged "old" females also showed no interaction between HFpEF and AOF and, importantly, no cardiovascular impact from HFpEF or AOF.

Running on empty: Factors underpinning impaired cardiac output reserve in heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is frequently attributed etiologically to an underlying left ventricular (LV) diastolic dysfunction, although its pathophysiology is far more complex and can exhibit significant variations among patients. This review endeavours to systematically unravel the pathophysiological heterogeneity by illustrating diverse mechanisms leading to an impaired cardiac output reserve, a central and prevalent haemodynamic abnormality in HFpEF patients. Drawing on previously published findings from our research group, we propose a pathophysiology-guided phenotyping based on the presence of: (1) LV diastolic dysfunction, (2) LV systolic pathologies, (3) arterial stiffness, (4) atrial impairment, (5) right ventricular dysfunction, (6) tricuspid valve regurgitation, and (7) chronotopic incompetence. Tailored to each specific phenotype, we explore various potential treatment options such as antifibrotic medication, diuretics, renal denervation and more. Our conclusion underscores the pivotal role of cardiac output reserve as a key haemodynamic abnormality in HFpEF, emphasizing that by phenotyping patients according to its individual pathomechanisms, insights into personalized therapeutic approaches can be gleaned.

Heart Failure with Preserved Ejection Fraction: How to Deal with This Chameleon

Heart failure with preserved ejection fraction (HFpEF) is characterized by a notable heterogeneity in both phenotypic and pathophysiological features, with a growing incidence due to the increase in median age and comorbidities such as obesity, arterial hypertension, and cardiometabolic disease. In recent decades, the development of new pharmacological and non-pharmacological options has significantly impacted outcomes, improving clinical status and reducing mortality. Moreover, a more personalized and accurate therapeutic management has been demonstrated to enhance the quality of life, diminish hospitalizations, and improve overall survival. Therefore, assessing the peculiarities of patients with HFpEF is crucial in order to obtain a better understanding of this disorder. Importantly, comorbidities have been shown to influence symptoms and prognosis, and, consequently, they should be carefully addressed. In this sense, it is mandatory to join forces with a multidisciplinary team in order to achieve high-quality care. However, HFpEF remains largely under-recognized and under-treated in clinical practice, and the diagnostic and therapeutic management of these patients remains challenging. The aim of this paper is to articulate a pragmatic approach for patients with HFpEF focusing on the etiology, diagnosis, and treatment of HFpEF.

Targeting HDAC6 to treat heart failure with preserved ejection fraction in mice

Heart failure with preserved ejection fraction (HFpEF) poses therapeutic challenges due to the limited treatment options. Building upon our previous research that demonstrates the efficacy of histone deacetylase 6 (HDAC6) inhibition in a genetic cardiomyopathy model, we investigate HDAC6's role in HFpEF due to their shared mechanisms of inflammation and metabolism. Here, we show that inhibiting HDAC6 with TYA-018 effectively reverses established heart failure and its associated symptoms in male HFpEF mouse models. Additionally, in male mice lacking Hdac6 gene, HFpEF progression is delayed and they are resistant to TYA-018's effects. The efficacy of TYA-018 is comparable to a sodium-glucose cotransporter 2 (SGLT2) inhibitor, and the combination shows enhanced effects. Mechanistically, TYA-018 restores gene expression related to hypertrophy, fibrosis, and mitochondrial energy production in HFpEF heart tissues. Furthermore, TYA-018 also inhibits activation of human cardiac fibroblasts and enhances mitochondrial respiratory capacity in cardiomyocytes. In this work, our findings show that HDAC6 impacts on heart pathophysiology and is a promising target for HFpEF treatment.

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

BACKGROUND

Heart 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.

METHODS

HFpEF 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.

RESULTS

GO 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.

CONCLUSIONS

The 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.