Heart Failure with Preserved Ejection Fraction

Insights into the post-translational modifications in heart failure

Heart failure (HF), as the terminal manifestation of multiple cardiovascular diseases, causes a huge socioeconomic burden worldwide. Despite the advances in drugs and medical-assisted devices, the prognosis of HF remains poor. HF is well-accepted as a myriad of subcellular dys-synchrony related to detrimental structural and functional remodelling of cardiac components, including cardiomyocytes, fibroblasts, endothelial cells and macrophages. Through the covalent chemical process, post-translational modifications (PTMs) can coordinate protein functions, such as re-localizing cellular proteins, marking proteins for degradation, inducing interactions with other proteins and tuning enzyme activities, to participate in the progress of HF. Phosphorylation, acetylation, and ubiquitination predominate in the currently reported PTMs. In addition, advanced HF is commonly accompanied by metabolic remodelling including enhanced glycolysis. Thus, glycosylation induced by disturbed energy supply is also important. In this review, firstly, we addressed the main types of HF. Then, considering that PTMs are associated with subcellular locations, we summarized the leading regulation mechanisms in organelles of distinctive cell types of different types of HF, respectively. Subsequently, we outlined the aforementioned four PTMs of key proteins and signaling sites in HF. Finally, we discussed the perspectives of PTMs for potential therapeutic targets in HF.

Blood pressure behavior during exercise in patients with diastolic dysfunction and a hypertensive response to exercise

A hypertensive response to exercise is a precursor leading to hypertension, which is a major risk factor for the development of heart failure and diastolic dysfunction. Herein, we aimed to assess blood pressure (BP) in patients with a hypertensive response to exercise and different degrees of diastolic dysfunction. Between January 2009 and December 2014, 373 patients with a hypertensive response to exercise (HRE) and echocardiographic data assessing diastolic function were enrolled at the University Hospital of Zurich. ANCOVA was used to assess the changes in BP response during exercise testing in individuals with different degrees of diastolic dysfunction. Normalization of systolic BP was blunted in patients with grade II and III diastolic dysfunction after 3 min of recovery in univariable [β (95%) - 9.2 (-13.8 to - 4.8) p < .001, -16.0 (-23.0 to 9.0) p < .001, respectively] and adjusted models. In fully adjusted models, when taking maximal effort into account, there were no differences with regard to systolic BP during exercise. Patients without diastolic dysfunction achieved higher heart rates (HRs) [both in absolute terms (p < .001) and as a percentage of the calculated maximum (p = .003)] and greater wattage (p < .001) at maximum exertion. The findings of this cross-sectional study suggest that exercise capacity is compromised in patients with diastolic dysfunction. A hypertensive response to exercise and the finding of a blunted BP recovery may help identify patients at risk of developing heart failure.

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.

Exploring the therapeutic potential of tetrahydrobiopterin for heart failure with preserved ejection fraction: A path forward

A large number of patients are affected by classical heart failure (HF) symptomatology with preserved ejection fraction (HFpEF) and multiorgan syndrome. Due to high morbidity and mortality rate, hospitalization and mortality remain serious socioeconomic problems, while the lack of effective pharmacological or device treatment means that HFpEF presents a major unmet medical need. Evidence from clinical and basic studies demonstrates that systemic inflammation, increased oxidative stress, and impaired mitochondrial function are the common pathological mechanisms in HFpEF. Tetrahydrobiopterin (BH4), beyond being an endogenous co-factor for catalyzing the conversion of some essential biomolecules, has the capacity to prevent systemic inflammation, enhance antioxidant resistance, and modulate mitochondrial energy production. Therefore, BH4 has emerged in the last decade as a promising agent to prevent or reverse the progression of disorders such as cardiovascular disease. In this review, we cover the clinical progress and limitations of using downstream targets of nitric oxide (NO) through NO donors, soluble guanylate cyclase activators, phosphodiesterase inhibitors, and sodium-glucose co-transporter 2 inhibitors in treating cardiovascular diseases, including HFpEF. We discuss the use of BH4 in association with HFpEF, providing new evidence for its potential use as a pharmacological option for treating HFpEF.

Chapter 2: Clinical and Mechanistic Potential of Sodium-Glucose Co-Transporter 2 (SGLT2) Inhibitors in Heart Failure with Preserved Ejection Fraction

Sodium-glucose co-transporter 2 inhibitors (SGLT2i) have emerged as an important approach for the treatment of heart failure in patients with or without diabetes. Although the precise mechanisms underpinning their clinical impact remain incompletely resolved, mechanistic studies and insights from major clinical trials have demonstrated the impact of SGLT2 inhibitors on numerous cardio-renal-metabolic pathways of relevance to heart failure with preserved ejection fraction (HFpEF), which, in the contemporary era, constitutes approximately half of all patients with heart failure. Despite rates of morbidity and mortality that are commensurate with those of heart failure with reduced ejection fraction, disease-modifying therapies have comparatively been severely lacking. As such, HFpEF remains among the greatest unmet needs in cardiovascular medicine. Within the past decade, HFpEF has been established as a highly integrated disorder, involving not only the cardiovascular system, but also the lungs, kidneys, skeletal muscle, and adipose tissue. Given their multisystem impact, SGLT2i offer unique promise in addressing the complex pathophysiology of HFpEF, and in recent randomized controlled trials, were shown to significantly reduce heart failure events and cardiovascular death in patients with HFpEF. Herein, we discuss several proposed mechanisms of clinical benefit of SGLT2i in HFpEF.

Porcupine inhibitor CGX1321 alleviates heart failure with preserved ejection fraction in mice by blocking WNT signaling

Heart failure with preserved ejection fraction (HFpEF) is highly prevalent, and lacks effective treatment. The aberration of WNT pathway underlies many pathological processes including cardiac fibrosis and hypertrophy, while porcupine is an acyltransferase essential for the secretion of WNT ligands. In this study we investigated the role of WNT signaling pathway in HFpEF as well as whether blocking WNT signaling by a novel porcupine inhibitor CGX1321 alleviated HFpEF. We established two experimental HFpEF mouse models, namely the UNX/DOCA model and high fat diet/L-NAME ("two-hit") model. The UNX/DOCA and "two-hit" mice were treated with CGX1321 (3 mg·kg-1·d-1) for 4 and 10 weeks, respectively. We showed that CGX1321 treatment significantly alleviated cardiac hypertrophy and fibrosis, thereby improving cardiac diastolic function and exercise performance in both models. Furthermore, both canonical and non-canonical WNT signaling pathways were activated, and most WNT proteins, especially WNT3a and WNT5a, were upregulated during the development of HEpEF in mice. CGX1321 treatment inhibited the secretion of WNT ligands and repressed both canonical and non-canonical WNT pathways, evidenced by the reduced phosphorylation of c-Jun and the nuclear translocation of β-catenin and NFATc3. In an in vitro HFpEF model, MCM and ISO-treated cardiomyocytes, knockdown of porcupine by siRNA leads to a similar inhibitory effect on WNT pathways, cardiomyocyte hypertrophy and cardiac fibroblast activation as CGX1321 did, whereas supplementation of WNT3a and WNT5a reversed the anti-hypertrophy and anti-fibrosis effect of CGX1321. We conclude that WNT signaling activation plays an essential role in the pathogenesis of HFpEF, and porcupine inhibitor CGX1321 exerts a therapeutic effect on HFpEF in mice by attenuating cardiac hypertrophy, alleviating cardiac fibrosis and improving cardiac diastolic function.

Heart failure with preserved ejection fraction and non-alcoholic fatty liver disease: new insights from bioinformatics

AIMS

Heart failure with preserved ejection fraction (HFpEF) and non-alcoholic fatty liver disease (NAFLD) are related conditions with an increasing incidence. The mechanism of their relationship remains undefined. Here, we aimed to explore the potential mechanisms, diagnostic markers, and therapeutic options for HFpEF and NAFLD.

METHODS AND RESULTS

HFpEF and NAFLD datasets were downloaded from the Gene Expression Omnibus (GEO) database. Common differentially expressed genes (DEGs) were screened for functional annotation. A protein-protein interaction network was constructed based on the STRING database, and hub genes were analysed using GeneMANIA annotation. ImmuCellAI (Immune Cell Abundance Identifier) was employed for analysis of immune infiltration. We also used validation datasets to validate the expression levels of hub genes and the correlation of immune cells. To screen for diagnostic biomarkers, we employed the least absolute shrinkage and selection operator and support vector machine-recursive feature elimination. Drug signature database was used to predict potential therapeutic drugs. Our analyses identified a total of 33 DEGs. Inflammation and immune infiltration played important roles in the development of both diseases. The data showed a close relationship between chemokine signalling pathway, cytokine-cytokine receptor interaction, calcium signalling pathway, neuroactive ligand-receptor interaction, osteoclast differentiation, and cyclic guanosine monophosphate-protein kinase G signalling pathway. We demonstrated that PRF1 (perforin 1) and IL2RB (interleukin-2 receptor subunit beta) proteins were perturbed by the diseases and may be the hub genes. The analysis showed that miR-375 may be a potential diagnostic marker for both diseases. Our drug prediction analysis showed that bosentan, eldecalcitol, ramipril, and probucol could be potential therapeutic options for the diseases.

CONCLUSIONS

Our findings revealed common pathogenesis, diagnostic markers, and therapeutic agents for HFpEF and NAFLD. There is need for further experimental studies to validate our findings.

Effects of treatment of non-alcoholic fatty liver disease on heart failure with preserved ejection fraction

In the past few decades, non-alcoholic fatty liver disease (NAFLD) and heart failure with preserved ejection fraction (HFpEF) have become the most common chronic liver disease and the main form of heart failure (HF), respectively. NAFLD is closely associated with HFpEF by sharing common risk factors and/or by boosting systemic inflammation, releasing other secretory factors, and having an expansion of epicardial adipose tissue (EAT). Therefore, the treatments of NAFLD may also affect the development and prognosis of HFpEF. However, no specific drugs for NAFLD have been approved by the Food and Drug Administration (FDA) and some non-specific treatments for NAFLD are applied in the clinic. Currently, the treatments of NAFLD can be divided into non-pharmacological and pharmacological treatments. Non-pharmacological treatments mainly include dietary intervention, weight loss by exercise, caloric restriction, and bariatric surgery. Pharmacological treatments mainly include administering statins, thiazolidinediones, glucagon-like peptide-1 receptor agonists, sodium-glucose cotransporter 2 inhibitors, and metformin. This review will mainly focus on analyzing how these treatments may affect the development and prognosis of HFpEF.

Prevention of cardiorenal damage: importance of albuminuria

Chronic kidney disease (CKD) is projected to become a leading global cause of death by 2040, and its early detection is critical for effective and timely management. The current definition of CKD identifies only advanced stages, when kidney injury has already destroyed &gt;50% of functioning kidney mass as reflected by an estimated glomerular filtration rate &lt;60 mL/min/1.73 m2 or a urinary albumin/creatinine ratio &gt;six-fold higher than physiological levels (i.e. &gt; 30 mg/g). An elevated urinary albumin-excretion rate is a known early predictor of future cardiovascular events. There is thus a ‘blind spot’ in the detection of CKD, when kidney injury is present but is undetectable by current diagnostic criteria, and no intervention is made before renal and cardiovascular damage occurs. The present review discusses the CKD ‘blind spot’ concept and how it may facilitate a holistic approach to CKD and cardiovascular disease prevention and implement the call for albuminuria screening implicit in current guidelines. Cardiorenal risk associated with albuminuria in the high-normal range, novel genetic and biochemical markers of elevated cardiorenal risk, and the role of heart and kidney protective drugs evaluated in recent clinical trials are also discussed. As albuminuria is a major risk factor for cardiovascular and renal disease, starting from levels not yet considered in the definition of CKD, the implementation of opportunistic or systematic albuminuria screening and therapy, possibly complemented with novel early biomarkers, has the potential to improve cardiorenal outcomes and mitigate the dismal 2040 projections for CKD and related cardiovascular burden.

Angiopoietins, vascular endothelial growth factors and secretory phospholipase A2 in heart failure patients with preserved ejection fraction

BACKGROUND

Heart failure (HF) is a growing public health burden, with high prevalence and mortality rates. A proportion of patients with HF have a normal ventricular ejection fraction (EF), referred to as HF with preserved EF (HFpEF), as opposed to patients with HF with reduced ejection fraction (HFrEF). HFpEF currently accounts for about 50% of all HF patients, and its prevalence is rising. Angiopoietins (ANGPTs), vascular endothelial growth factors (VEGFs) and secretory phospholipases A₂ (sPLA₂s) are proinflammatory mediators and key regulators of endothelial cells.

METHODS

The aim of this study was to analyze the plasma concentrations of angiogenic (ANGPT1, ANGPT2, VEGF-A) and lymphangiogenic (VEGF-C, VEGF-D) factors and the plasma activity of sPLA₂ in patients with HFpEF and HFrEF compared to healthy controls.

RESULTS

The concentration of ANGPT1 was reduced in HFrEF compared to HFpEF patients and healthy controls. ANGPT2 levels were increased in both HFrEF and HFpEF subjects compared to controls. The ANGPT2/ANGPT1 ratio was increased in HFrEF patients compared to controls. The concentrations of both VEGF-A and VEGF-C did not differ among the three groups examined. VEGF-D was increased in both HFrEF and HFpEF patients compared to controls. Plasma activity of sPLA₂ was increased in HFrEF but not in HFpEF patients compared to controls.

CONCLUSIONS

Our results indicate that three different classes of proinflammatory regulators of vascular permeability and smoldering inflammation are selectively altered in HFrEF or HFpEF patients. Studies involving larger cohorts of these patients will be necessary to demonstrate the clinical implications of our findings.

SIRT6 Mitigates Heart Failure With Preserved Ejection Fraction in Diabetes

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) is a growing health problem without effective therapies. Epidemiological studies indicate that diabetes is a strong risk factor for HFpEF, and about 45% of patients with HFpEF are suffering from diabetes, yet the underlying mechanisms remain elusive.

METHODS

Using a combination of echocardiography, hemodynamics, RNA-sequencing, molecular biology, in vitro and in vivo approaches, we investigated the roles of SIRT6 (sirtuin 6) in regulation of endothelial fatty acid (FA) transport and HFpEF in diabetes.

RESULTS

We first observed that endothelial SIRT6 expression was markedly diminished in cardiac tissues from heart failure patients with diabetes. We then established an experimental mouse model of HFpEF in diabetes induced by a combination of the long-term high-fat diet feeding and a low-dose streptozocin challenge. We also generated a unique humanized SIRT6 transgenic mouse model, in which a single copy of human SIRT6 transgene was engineered at mouse Rosa26 locus and conditionally induced with the Cre-loxP technology. We found that genetically restoring endothelial SIRT6 expression in the diabetic mice ameliorated diastolic dysfunction concurrently with decreased cardiac lipid accumulation. SIRT6 gain- or loss-of-function studies showed that SIRT6 downregulated endothelial FA uptake. Mechanistically, SIRT6 suppressed endothelial expression of PPARγ through SIRT6-dependent deacetylation of histone H3 lysine 9 around PPARγ promoter region; and PPARγ reduction mediated SIRT6-dependent inhibition of endothelial FA uptake. Importantly, oral administration of small molecule SIRT6 activator MDL-800 to diabetic mice mitigated cardiac lipid accumulation and diastolic dysfunction.

CONCLUSIONS

The impairment of endothelial SIRT6 expression links diabetes to HFpEF through the alteration of FA transport across the endothelial barrier. Genetic and pharmacological strategies that restored endothelial SIRT6 function in mice with diabetes alleviated experimental HFpEF by limiting FA uptake and improving cardiac metabolism, thus warranting further clinical evaluation.

Construction and analysis of heart failure diagnosis model based on random forest and artificial neural network

Heart failure is a global health problem and the number of sufferers is increasing as the population grows and ages. Existing diagnostic techniques for heart failure have various limitations in the clinical setting and there is a need to develop a new diagnostic model to complement the existing diagnostic methods. In recent years, with the development and improvement of gene sequencing technology, more genes associated with heart failure have been identified. We screened for differentially expressed genes in heart failure using available gene expression data from the Gene Expression Omnibus database and identified 6 important genes by a random forest classifier (ASPN, MXRA5, LUM, GLUL, CNN1, and SERPINA3). And we have successfully constructed a new heart failure diagnostic model using an artificial neural network and validated its diagnostic efficacy in a public dataset. We calculated heart failure-related differentially expressed genes and obtained 24 candidate genes by random forest classification, and selected the top 6 genes as important genes for subsequent analysis. The prediction weights of the genes of interest were determined by the neural network model and the model scores were evaluated in 2 independent sample datasets (GSE16499 and GSE57338 datasets). Since the weights of RNA-seq predictions for constructing neural network models were theoretically more suitable for disease classification of RNA-seq data, the GSE57338 dataset had the best performance in the validation results. The diagnostic model derived from our study can be of clinical value in determining the likelihood of HF occurring through cardiac biopsy. In the meantime, we need to further investigate the accuracy of the diagnostic model based on the results of our study.

Targeting efficacy of spironolactone in patients with heart failure with preserved ejection fraction: the TOPCAT study

AIMS

We aimed to explore the heterogeneous treatment effects (HTEs) for spironolactone treatment in patients with Heart failure with preserved ejection fraction (HFpEF) and examine the efficacy and safety of spironolactone medication, ensuring a better individualized therapy.

METHODS AND RESULTS

We used the causal forest algorithm to discover the heterogeneous treatment effects (HTEs) from patients in the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) trial. Cox regressions were performed to assess the hazard ratios (HRs) of spironolactone medication for cardiovascular death and drug discontinuation in each group. The causal forest model revealed three representative covariates and participants were partitioned into four subgroups which were Group 1 (baseline BMI ≤ 31.71 kg/m² and baseline ALP ≤ 80 U/L, n = 759); Group 2 (BMI ≤ 31.71 kg/m² and ALP > 80 U/L, n = 1088); Group 3 (BMI > 31.71 kg/m² , and WBC ≤ 6.6 cells/μL, n = 633); Group 4 (BMI > 31.71 kg/m² and WBC > 6.6 cells/μL, n = 832), respectively. In the four subgroups, spironolactone therapy reduced the risk of cardiovascular death in high-risk group (Group 4) with both high BMI and WBC count (HR: 0.76; 95% CI 0.58 to 0.99; P = 0.045) but increased the risk in low-risk group (Group 1) with both low BMI and ALP (HR: 1.45; 95% CI 1.02 to 2.07; P = 0.041; P for interaction = 0.020) but showed similar risk of drug discontinuation (P for interaction = 0.498).

CONCLUSION

Our study manifested the HTEs of spironolactone in patients with HFpEF. Spironolactone treatment in HFpEF patients is feasible and effective in patients with high BMI and WBC while harmful in patients with low BMI and ALP. Machine learning model could be meaningful for improved categorization of patients with HFpEF, ensuring a better individualized therapy in the clinical setting.

Heart Failure with Preserved Ejection Fraction: Pathogenesis, Diagnosis, Exercise, and Medical Therapies

Heart failure with preserved ejection fraction (HFpEF) accounts for more than one-half of total heart failure cases, with a high prevalence and poor prognosis, especially in older and female patients. Patients with HFpEF are characterized by hypertension, left ventricular hypertrophy, and diastolic dysfunction, and the main symptoms are dyspnea and exercise intolerance. HFpEF is currently poorly studied, and pharmacological treatment for HFpEF is still underexplored. Accumulating clinical trials have shown that exercise could exert benefits on diastolic dysfunction and quality of life in patients with HFpEF. However, there is a high limitation for applying exercise therapy due to exercise intolerance in patients with HFpEF. Key effectors of exercise-protection could be novel therapeutic targets for developing drugs to prevent and treat HFpEF. In this review article, we provide an overview of the pathogenic factors, diagnostic methods, research animal models, the mechanisms of exercise-mediated cardiac protection, and current treatments for HFpEF.

Acetylation and phosphorylation changes to cardiac proteins in experimental HFpEF due to metabolic risk reveal targets for treatment

AIMS

Despite the high prevalence of heart failure with preserved ejection fraction (HFpEF), the pathomechanisms remain elusive and specific therapy is lacking. Disease-causing factors include metabolic risk, notably obesity. However, proteomic changes in HFpEF are poorly understood, hampering therapeutic strategies. We sought to elucidate how metabolic syndrome affects cardiac protein expression, phosphorylation and acetylation in the Zucker diabetic fatty/Spontaneously hypertensive heart failure F1 (ZSF1) rat HFpEF model, and to evaluate changes regarding their potential for treatment.

MAIN METHODS

ZSF1 obese and lean rats were fed a Purina diet up to the onset of HFpEF in the obese animals. We quantified the proteome, phosphoproteome and acetylome of ZSF1 obese versus lean heart tissues by mass spectrometry and singled out targets for site-specific evaluation.

KEY FINDINGS

The acetylome of ZSF1 obese versus lean hearts was more severely altered (21 % of proteins changed) than the phosphoproteome (9 %) or proteome (3 %). Proteomic alterations, confirmed by immunoblotting, indicated low-grade systemic inflammation and endothelial remodeling in obese hearts, but low nitric oxide-dependent oxidative/nitrosative stress. Altered acetylation in ZSF1 obese hearts mainly affected pathways important for metabolism, energy production and mechanical function, including hypo-acetylation of mechanical proteins but hyper-acetylation of proteins regulating fatty acid metabolism. Hypo-acetylation and hypo-phosphorylation of elastic titin in ZSF1 obese hearts could explain myocardial stiffening.

SIGNIFICANCE

Cardiometabolic syndrome alters posttranslational modifications, notably acetylation, in experimental HFpEF. Pathway changes implicate a HFpEF signature of low-grade inflammation, endothelial dysfunction, metabolic and mechanical impairment, and suggest titin stiffness and mitochondrial metabolism as promising therapeutic targets.

Modern Approaches for the Treatment of Heart Failure: Recent Advances and Future Perspectives

Heart failure (HF) is a progressively deteriorating medical condition that significantly reduces both the patients' life expectancy and quality of life. Even though real progress was made in the past decades in the discovery of novel pharmacological treatments for HF, the prevention of premature deaths has only been marginally alleviated. Despite the availability of a plethora of pharmaceutical approaches, proper management of HF is still challenging. Thus, a myriad of experimental and clinical studies focusing on the discovery of new and provocative underlying mechanisms of HF physiopathology pave the way for the development of novel HF therapeutic approaches. Furthermore, recent technological advances made possible the development of various interventional techniques and device-based approaches for the treatment of HF. Since many of these modern approaches interfere with various well-known pathological mechanisms in HF, they have a real ability to complement and or increase the efficiency of existing medications and thus improve the prognosis and survival rate of HF patients. Their promising and encouraging results reported to date compel the extension of heart failure treatment beyond the classical view. The aim of this review was to summarize modern approaches, new perspectives, and future directions for the treatment of HF.

Urinary orosomucoid is associated with diastolic dysfunction and carotid arteriopathy in the general population. Cross-sectional data from the Tromsø study

Objectives. Urinary albumin excretion is a risk marker for cardiovascular disease (CVD). Studies suggest that urinary orosomucoid may be a more sensitive marker of general endothelial dysfunction than albuminuria. The aim of this population-based cross-sectional study was to examine the associations between urinary orosomucoid to creatinine ratio (UOCR), urinary albumin to creatinine ratio (UACR) and subclinical CVD. Design. From the Tromsø Study (2007/2008), we included all men and women who had measurements of urinary orosomucoid (n = 7181). Among these, 6963 were examined with ultrasound of the right carotid artery and 2245 with echocardiography. We assessed the associations between urinary markers and subclinical CVD measured as intima media thickness of the carotid artery, presence and area of carotid plaque and diastolic dysfunction (DD). UOCR and UACR were dichotomized as upper quartile versus the three lowest. Results. High UOCR, adjusted for UACR, age, cardiovascular risk factors and kidney function, was associated with presence of DD in men (OR: 3.18, 95% CI [1.27, 7.95], p = .013), and presence of plaque (OR: 1.20, 95% CI [1.01, 1.44], p = .038) and intima media thickness in women (OR: 1.34, 95% CI [1.09, 1.65], p = .005). Analyses showed no significant interaction between sex and UOCR for any endpoints. UACR was not significantly associated with DD, but the associations with intima media thickness and plaque were of magnitudes comparable to those observed for UOCR. Conclusions. UOCR was positively associated with subclinical CVD. We need prospective studies to confirm whether UOCR is a clinically useful biomarker and to study possible sex differences.

Comparative Efficacy of Single Pill Combinations of Azilsartan Medoxomil/Chlorthalidone and Losartan/Hydrochlorothiazide in Patients with Hypertension and Heart Failure with Preserved Ejection Fraction

Aim. To study the effects of azilsartan medoxomil/chlorthalidone (AZM/CTD) and losartan/hydrochlorothiazide (LOS/HCT) combinations for NTproBNP levels, 6-minute walk test results, hydration status along with their antihypertensive efficacy according to clinical and 24-hour blood pressure in patients with hypertension and heart failure with preserved ejection fraction (HFpEF).

Material and methods. An open randomized study included 56 patients with uncontrolled or untreated hypertension and HFpEF. Patients randomized to receive the AZM/CTD 40/12.5 mg/day (group 1; n=28) or LOS/HCT 100/12.5 (group 2; n=28) within 4 weeks. Patients who did not achieve the target BP <140/<90 mm Hg study drug dose was intensified: in the first group, an increase in the dose of AZM/CTD 40/25 mg/day, in the second group, an increase in the dose of LOS/HCT 100/25 mg/day. The observation period was 12 weeks. All patients underwent a clinical examination with an assessment of symptoms and/or signs of HF, laboratory and instrumental studies, including NT-proBNP, ambulatory blood pressure (BP) monitoring, applanation tonometry, a 6-minute walk test (6MWT), echocardiography. In order to assess the status of hydration, bioimpedance vector analysis (BIVA) was performed. HFpEF was diagnosed according to the HFA-PEFF algorithm. The results were considered statistically significant at p<0.05.

Results. After 12 weeks, 92% of patients in the first and 78% of patients in the second group reached the target clinical BP (р<0,05). Average daily BP <130/ <80 mm Hg was reached by 82% of patients treated with the combination of AZM/CTD, compared with 67% treated with the combination of losartan/HCT (p<0.05). After 12 weeks, patients from both groups showed a significant decrease in systolic and diastolic blood pressure, central blood pressure, and a decrease in pulse wave velocity, which was more significantly significant in the first group of patients (p<0.05). During therapy in both groups of patients, a significant decrease in the level of NT-proBNP was observed: in the first group from 300 [199; 669] pg/ml to 156 [157; 448] pg/ml (p=0,003), in the second group from 298 [180; 590] pg/ml to 194 [140; 360] pg/ml (p=0,006), an increase in the distance during the 6MWT from 317 [210; 398] m to 380 [247; 455] m (p=0,006) in in the first group and an improvement in the hydration status according to the BIA data, but more significantly significant in the first group (p<0.001).

Conclusion. In patients with hypertension and HFpEF, therapy with the AZM/CTD combination compared with LOS/HCT is accompanied by a more pronounced antihypertensive effect in terms of ambulatory and peripheral blood pressure, central blood pressure, NTproBNP levels, increased distance in 6MWT and achievement of euvolemia status. 

Signaling cascades in the failing heart and emerging therapeutic strategies

Chronic heart failure is the end stage of cardiac diseases. With a high prevalence and a high mortality rate worldwide, chronic heart failure is one of the heaviest health-related burdens. In addition to the standard neurohormonal blockade therapy, several medications have been developed for chronic heart failure treatment, but the population-wide improvement in chronic heart failure prognosis over time has been modest, and novel therapies are still needed. Mechanistic discovery and technical innovation are powerful driving forces for therapeutic development. On the one hand, the past decades have witnessed great progress in understanding the mechanism of chronic heart failure. It is now known that chronic heart failure is not only a matter involving cardiomyocytes. Instead, chronic heart failure involves numerous signaling pathways in noncardiomyocytes, including fibroblasts, immune cells, vascular cells, and lymphatic endothelial cells, and crosstalk among these cells. The complex regulatory network includes protein-protein, protein-RNA, and RNA-RNA interactions. These achievements in mechanistic studies provide novel insights for future therapeutic targets. On the other hand, with the development of modern biological techniques, targeting a protein pharmacologically is no longer the sole option for treating chronic heart failure. Gene therapy can directly manipulate the expression level of genes; gene editing techniques provide hope for curing hereditary cardiomyopathy; cell therapy aims to replace dysfunctional cardiomyocytes; and xenotransplantation may solve the problem of donor heart shortages. In this paper, we reviewed these two aspects in the field of failing heart signaling cascades and emerging therapeutic strategies based on modern biological techniques.

Cardiac mechanisms of the beneficial effects of SGLT2 inhibitors in heart failure: Evidence for potential off-target effects

Sodium glucose cotransporter 2 inhibitors (SGLT2i) constitute a promising drug treatment for heart failure patients with either preserved or reduced ejection fraction. Whereas SGLT2i were originally developed to target SGLT2 in the kidney to facilitate glucosuria in diabetic patients, it is becoming increasingly clear that these drugs also have important effects outside of the kidney. In this review we summarize the literature on cardiac effects of SGLT2i, focussing on pro-inflammatory and oxidative stress processes, ion transport mechanisms controlling sodium and calcium homeostasis and metabolic/mitochondrial pathways. These mechanisms are particularly important as disturbances in these pathways result in endothelial dysfunction, diastolic dysfunction, cardiac stiffness, and cardiac arrhythmias that together contribute to heart failure. We review the findings that support the concept that SGLT2i directly and beneficially interfere with inflammation, oxidative stress, ionic homeostasis, and metabolism within the cardiac cell. However, given the very low levels of SGLT2 in cardiac cells, the evidence suggests that SGLT2-independent effects of this class of drugs likely occurs via off-target effects in the myocardium. Thus, while there is still much to be understood about the various factors which determine how SGLT2i affect cardiac cells, much of the research clearly demonstrates that direct cardiac effects of these SGLT2i exist, albeit mediated via SGLT2-independent pathways, and these pathways may play a role in explaining the beneficial effects of SGLT2 inhibitors in heart failure.

[Update on diastolic heart failure]

In August 2021, an update of the European Society of Cardiology-Heart Failure Association guideline for the diagnosis and treatment of heart failure was released. To review the changes implied by current guidelines regarding the diagnosis and treatment of patients with heart failure and preserved left ventricular ejection fraction (HFpEF). The diagnosis of HFpEF requires the combined presence of clinical signs, left ventricular ejection fraction ≥ 50%, elevated natriuretic peptides, and elevated left ventricular filling pressure. If the diagnosis remains equivocal, a stress test is recommended. The targeted identification and treatment of comorbid conditions is key for a holistic therapeutic approach to HFpEF. Diuretics are recommended in congested patients with HFpEF in order to alleviate signs and symptoms. The treatment of diabetic patients with heart failure should include a sodium glucose co-transporter‑2 (SGLT2) inhibitor. All patients with HFpEF should be enrolled in a multidisciplinary heart failure management program aiming to improve self-care strategies and offer participation in an exercise program. It was recently shown for the first time in a randomized trial that hard clinical endpoints could be reduced in patients with HFpEF using the SGLT2 inhibitor empagliflozin. It is expected that this finding will become part of updated treatment recommendations in the near future. Although challenging, the early diagnosis of HFpEF is key to averting the poor prognosis associated with this frequent condition. Multidisciplinary care and innovative pharmacologic and non-pharmacologic therapies, however, can improve quality of life, exercise tolerance, and prognosis.

Associations between Calcium Channel Blockers Therapy and Mortality in Heart Failure with Preserved Ejection Fraction

BACKGROUND

Treatment of heart failure with preserved ejection fraction (HFpEF) is urgently needed; however, effective treatments are lacking. Current evidence showed a possible association between the use of calcium channel blockers (CCBs) and improved outcomes in HFpEF patients.

AIM

We aimed to investigate the impact of CCBs on mortality in patients with HFpEF.

METHODS

This was a post hoc analysis of the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist trial. The primary outcome was all-cause mortality. The secondary outcomes were cardiovascular and noncardiovascular mortality. We analyzed hazard ratios (HRs) in patients taking CCBs compared with those not taking CCBs using Cox proportional hazard models.

RESULTS

We considered 3440 HFpEF patients. The mean follow-up period was 3.4 ± 1.7 years, and 530 patients died during the study period. All-cause mortality rates in patients taking and not taking CCB were 37.3 and 50.8 events per 1,000 person-years, respectively. The adjusted HR for all-cause mortality was significantly lower in those taking CCBs than those not taking CCBs (HR: 0.72, 95% Cl: 0.59 to 0.88, p = 0.001). The risk of cardiovascular and noncardiovascular mortality was also significantly lower in patients taking CCBs than in those not taking CCBs (HR: 0.75, 95% Cl: 0.59 to 0.96, p = 0.023 and HR: 0.68, 95% Cl: 0.49 to 0.93, p = 0.018, respectively).

CONCLUSION

The use of CCBs was associated with reduced risks of mortality in patients with HFpEF.

Gut Microbiota in Heart Failure Patients With Preserved Ejection Fraction (GUMPTION Study)

Introduction: Heart failure with preserved ejection fraction (HFpEF) is associated with disrupted intestinal epithelial function, resulting from intestinal congestion. Intestinal congestion changes the morphology and permeability of the intestinal wall, and it becomes easy for the gut microbiota to change and transfer. Intervention on gut microbiota may become a new target for HFpEF treatment. However, the characteristics of gut microbiota in patients with HFpEF remain unknown. This preliminary report aims to detect the structure of gut microbiota in HFpEF patients so as to explore their characteristic changes, thereby providing a theoretical basis for future research. Methods: This research recruited 30 patients diagnosed with HFpEF and 30 healthy individuals. Stool specimens of research subjects were collected separately, and the microarray analyses of gut microbiota were conducted by Illumina high-throughput DNA sequencing. The differences in gut microbiota composition, alpha diversity, and beta diversity between the two groups were finally obtained. Results: The composition of gut microbiota was significantly different between the two groups. At the phylum classification level, the abundance of Synergistetes tended to be higher in the HFpEF group (P = 0.012). At genus classification level, the abundance of Butyricicoccus (P < 0.001), Sutterella (P = 0.004), Lachnospira (P = 0.003), and Ruminiclostridium (P = 0.009) in the HFpEF group were lower, while the abundance of Enterococcus (P < 0.001) and Lactobacillus (P = 0.005) were higher. According to the Chao index of alpha diversity analysis, HFpEF patients showed a nominally significant lower species richness when compared with controls (P = 0.046). However, there was no statistical difference in the Shannon index (P = 0.159) and Simpson index (P = 0.495), indicating that there was no difference in species diversity between the two groups. Beta diversity analysis revealed a highly significant separation of HFpEF patients and controls. Conclusions: An imbalance in the gut microbiota of HFpEF patients was observed. Patients with HFpEF have an increased abundance of microbiota associated with inflammation and a decreased abundance of microbiota associated with anti-inflammatory effects in the gut environment. In line with that, the species richness of gut microbiota in HFpEF patients tended to be lower.

Left Atrial Stiffness Index Independently Predicts Exercise Intolerance and Quality of Life in Older, Obese Patients With Heart Failure With Preserved Ejection Fraction

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) is the fastest growing form of HF and is associated with high morbidity and mortality. The primary chronic symptom in HFpEF is exercise intolerance, associated with reduced quality of life. Emerging evidence implicates left atrial (LA) dysfunction as an important pathophysiologic mechanism. Here we extend prior observations by relating LA dysfunction to peak oxygen uptake (peak VO₂), physical function (distance walked in 6 minutes [6MWD]) and quality of life (Kansas City Cardiomyopathy Questionnaire).

METHODS AND RESULTS

We compared 75 older, obese, patients with HFpEF with 53 healthy age-matched controls. LA strain was assessed by magnetic resonance cine imaging using feature tracking. LA function was defined according to its 3 distinct phases, with the LA serving as a reservoir during systole, as a conduit during early diastole, and as a booster pump at the end of diastole. The LA stiffness index was calculated as the ratio of early mitral inflow velocity-to-early annular tissue velocity (E/e', by Doppler ultrasound examination) and LA reservoir strain. HFpEF had a decreased reservoir strain (16.4 ± 4.4% vs 18.2 ± 3.5%, P = .018), lower conduit strain (7.7 ± 3.3% vs 9.1 ± 3.4%, P = .028), and increased stiffness index (0.86 ± 0.39 vs 0.53 ± 0.18, P < .001), as well as decreased peak VO₂, 6MWD, and lower quality of life. Increased LA stiffness was independently associated with impaired peak VO₂ (β = 9.0 ± 1.6, P < .001), 6MWD (β = 117 ± 22, P = .003), and Kansas City Cardiomyopathy Questionnaire score (β = -23 ± 5, P = .001), even after adjusting for clinical covariates.

CONCLUSIONS

LA stiffness is independently associated with impaired exercise tolerance and quality of life and may be an important therapeutic target in obese HFpEF.

REGISTRATION

NCT00959660.

Histological and haemodynamic characterization of right ventricle in sedentary and trained rats with heart failure with preserved ejection fraction

NEW FINDINGS

What is the central question of this study? Right ventricle (RV) dysfunction is highly prevalent in heart failure with preserved ejection fraction (HFpEF), nearly doubling the risk of death: what are the RV functional and structural changes in HFpEF and how does aerobic exercise impact them? What is the main finding and its importance? The HFpEF ZSF1 rat model presents RV structural and functional changes mimicking the human condition. Aerobic exercise prevented the decline in V ̇ O 2 max , lowered surrogate markers of RV overload (e.g., higher mean and maximum systolic pressure) and improved diastolic dysfunction (e.g., end-diastolic pressure and relaxation time constant). This emphasizes the importance of using exercise to manage HFpEF.

ABSTRACT

Right ventricle (RV) dysfunction is highly prevalent in heart failure with preserved ejection fraction (HFpEF) and is a marker of poor prognosis. We assessed the obese ZSF1 rat model of HFpEF to ascertain if these animals also develop RV dysfunction and evaluated whether aerobic exercise could prevent this. Obese ZSF1 rats were randomly allocated to an aerobic exercise training group (n = 7; treadmill running, 5 days/week, 60 min/day, 15 m/min for 5 weeks) or to a sedentary group (n = 7). We used lean ZSF1 rats (n = 7) as the control group. After 5 weeks, rats were submitted to an exercise tolerance test and invasive haemodynamic evaluation, killed and samples from the RV collected for histological analysis. Obese sedentary ZSF1 rats showed lower V ̇ O 2 max , RV pressure overload (e.g., higher mean and maximum systolic pressure) and diastolic dysfunction (e.g., higher minimum and end-diastolic pressure and relaxation time constant), paralleled by RV cardiomyocyte hypertrophy. Except for cardiomyocyte hypertrophy, aerobic exercise prevented these functional changes. Our data support that this model of HFpEF shows functional and structural changes in the RV that resemble the human HFpEF phenotype, reinforcing its utility to understand this pathophysiology and to adress novel therapeutic targets to manage HFpEF. In addition, we showed that aerobic exercise is cardioprotective for the RV. A deeper knowledge of the mechanisms underlying the benefits of aerobic exercise could also lead to the identification of therapeutic targets to be further explored.

Heart failure clinical care analysis uncovers risk reduction opportunities for preserved ejection fraction subtype

Heart failure (HF) has no cure and, for HF with preserved ejection fraction (HFpEF), no life-extending treatments. Defining the clinical epidemiology of HF could facilitate earlier identification of high-risk individuals. We define the clinical epidemiology of HF subtypes (HFpEF and HF with reduced ejection fraction [HFrEF]), identified among 2.7 million individuals receiving routine clinical care. Differences in patterns and rates of accumulation of comorbidities, frequency of hospitalization, use of specialty care, were defined for each HF subtype. Among 28,156 HF cases, 8322 (30%) were HFpEF and 11,677 (42%) were HFrEF. HFpEF was the more prevalent subtype among older women. 177 Phenotypes differentially associated with HFpEF versus HFrEF. HFrEF was more frequently associated with diagnoses related to ischemic cardiac injury while HFpEF was associated more with non-cardiac comorbidities and HF symptoms. These comorbidity patterns were frequently present 3 years prior to a HFpEF diagnosis. HF subtypes demonstrated distinct patterns of clinical co-morbidities and disease progression. For HFpEF, these comorbidities were often non-cardiac and manifested prior to the onset of a HF diagnosis. Recognizing these comorbidity patterns, along the care continuum, may present a window of opportunity to identify individuals at risk for developing incident HFpEF.

The Potential Therapeutic Role of Celastrol in Patients With Heart Failure With Preserved Ejection Fraction

Analysis of left ventricular systolic dysfunction remained at the centre of heart failure research for many years (also known as heart failure with reduced ejection fraction, HFrEF). Although more than 50% of all heart failure patients experience a form of heart failure characterised by preserved ejection fraction (HFpEF), the pathophysiological mechanisms leading to this form of heart failure remain not well-understood. Several evidence-based treatments for HFrEF are in routine use, but there are limited evidence-based therapies for HFpEF. The effects of these remain controversial, with current treatment options being limited to managing the associated symptoms and conditions. Accumulating evidence demonstrates that pro-inflammatory and oxidative stress pathways play key roles in the development and progression of HFpEF, such as the Unfolded Protein Response (UPR) and inducible nitric oxide synthase. Celastrol, derived from medicinal plants, is a bioactive compound with strong anti-inflammatory properties, which could deem it as fruitful in overcoming the effects of such dysregulated UPR. This literature review therefore focuses on Celastrol's anti-inflammatory and antioxidant activities, alongside its other potential therapeutic activities, and its ability to impede the pathways that are thought to be involved in the development of HFpEF, such as the JAK2/STAT pathway, to elucidate the potential therapeutic role of this bioactive compound, in the treatment of HFpEF.

Sacubitril-valsartan as a treatment for apparent resistant hypertension in patients with heart failure and preserved ejection fraction

Aims

Patients with heart failure and preserved ejection fraction (HFpEF) frequently have difficult-to-control hypertension. We examined the effect of neprilysin inhibition on ‘apparent resistant hypertension’ in patients with HFpEF in the PARAGON-HF trial, which compared the effect of sacubitril–valsartan with valsartan.

Methods and results

In this post hoc analysis, patients were categorized according to systolic blood pressure at the end of the valsartan run-in (n = 4795). ‘Apparent resistant hypertension’ was defined as systolic blood pressure ≥140 mmHg (≥135 mmHg if diabetes) despite treatment with valsartan, a calcium channel blocker, and a diuretic. ‘Apparent mineralocorticoid receptor antagonist (MRA)-resistant’ hypertension was defined as systolic blood pressure ≥140 mmHg (≥135 mmHg if diabetes) despite the above treatments and an MRA. The primary outcome in the PARAGON-HF trial was a composite of total hospitalizations for heart failure and death from cardiovascular causes. We examined clinical endpoints and the safety of sacubitril–valsartan according to the hypertension category. We also examined reductions in blood pressure from the end of valsartan run-in to Weeks 4 and 16 after randomization. Overall, 731 patients (15.2%) had apparent resistant hypertension and 135 (2.8%) had apparent MRA-resistant hypertension. The rate of the primary outcome was higher in patients with apparent resistant hypertension [17.3; 95% confidence interval (CI) 15.6–19.1 per 100 person-years] compared to those with a controlled systolic blood pressure (13.4; 12.7–14.3 per 100 person-years), with an adjusted rate ratio of 1.28 (95% CI 1.05–1.57). The reduction in systolic blood pressure at Weeks 4 and 16, respectively, was greater with sacubitril–valsartan vs. valsartan in patients with apparent resistant hypertension [−4.8 (−7.0 to −2.5) and 3.9 (−6.6 to −1.3) mmHg] and apparent MRA-resistant hypertension [−8.8 (−14.0 to −3.5) and −6.3 (−12.5 to −0.1) mmHg]. The proportion of patients with apparent resistant hypertension achieving a controlled systolic blood pressure by Week 16 was 47.9% in the sacubitril–valsartan group and 34.3% in the valsartan group [adjusted odds ratio (OR) 1.78, 95% CI 1.30–2.43]. In patients with apparent MRA-resistant hypertension, the respective proportions were 43.6% vs. 28.4% (adjusted OR 2.63, 95% CI 1.18–5.89).

Conclusion

Sacubitril–valsartan may be useful in treating apparent resistant hypertension in patients with HFpEF, even in those who continue to have an elevated blood pressure despite treatment with at least four antihypertensive drug classes, including an MRA.

Clinical trial registration

PARAGON-HF: ClinicalTrials.gov Identifier NCT01920711.

Association of the classification and severity of heart failure with the incidence of contrast-induced acute kidney injury

Congestive heart failure (HF) is a known risk factor of contrast-induced acute kidney injury (CI-AKI). However, the relationship of the classification and severity of HF with CI-AKI remains under-explored. From January 2009 to April 2019, we recruited patients undergoing elective PCI who had complete pre- and post-operative creatinine data. According to the levels of ejection fraction (EF), HF was classified as HF with reduced EF (HFrEF) [EF < 40%], HF with mid-range EF (HFmrEF) [EF 40–49%] and HF with preserved EF (HFpEF) [EF ≥ 50%]. CI-AKI was defined as an increase of either 25% or 0.5 mg/dL (44.2 μmoI/L) in serum baseline creatinine level within 72 h following the administration of the contrast agent. A total of 3848 patients were included in the study; mean age 67 years old, 33.9% females, 48.1% with HF, and 16.9% with CI-AKI. In multivariate logistic regression analysis, HF was an independent risk factor for CI-AKI (OR 1.316, p value < 0.05). Among patients with HF, decreased levels of EF (OR 0.985, p value < 0.05) and elevated levels of N-terminal pro b-type natriuretic peptide (NT-proBNP) (OR 1.168, p value < 0.05) were risk factors for CI-AKI. These results were consistent in subgroup analysis. Patients with HFrEF were more likely to develop CI-AKI than those with HFmrEF or HFpEF (OR 0.852, p value = 0.031). Additionally, lower levels of EF were risk factors for CI-AKI in the HFrEF and HFmrEF groups, but not in the HFpEF group. NT-proBNP was an independent risk factor for CI-AKI in the HFrEF, HFmrEF and HFpEF groups. Elevated levels of NT-proBNP are independent risk factors for CI-AKI irrespective of the classification of HF. Lower levels of EF were risk factors for CI-AKI in the HFrEF and HFmrEF groups, but not in the HFpEF group.

Signs of diastolic dysfunction are graded by serum testosterone levels in aging C57BL/6 male mice

We investigated whether maladaptive, age-associated changes in heart structure and function were linked to circulating testosterone levels. Male C57BL/6 mice had a gonadectomy (GDX) or sham surgery at 4 weeks and effects of GDX on the heart were examined with echocardiography. Serum testosterone was measured with ELISA. Left ventricular (LV) mass increased with age but was smaller in GDX mice than sham at 18 months (144.0 ± 8.7 vs 118.2 ± 11.9 mg; p = 0.009). The isovolumic relaxation time (IVRT) declined with age but was prolonged in GDX mice at 18 months (10.5 ± 0.8 vs 12.5 ± 0.5 msec, p = 0.008). Ejection fraction did not change with age or GDX, but E/A ratios were lower in GDX mice than controls at 18 months (1.6 ± 0.2 vs 1.3 ± 0.1, p = 0.021). When links between serum testosterone and cardiac parameters were examined longitudinally in 18-24-month-old mice, LV mass declined with decreasing testosterone (β = 37.70, p = 0.016), however IVRT increased as testosterone decreased (β=-2.69, p = 0.036). Since longer IVRT and lower E/A ratios are signs of diastolic dysfunction, low circulating testosterone may promote or exacerbate diastolic dysfunction in older males. These findings suggest that lower testosterone directly modifies heart structure and function to promote maladaptive remodeling and diastolic dysfunction in the aging heart.

Renal Dysfunction and Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) and chronic kidney disease (CKD) constitute a high-risk phenotype with significant morbidity and mortality and poor prognosis. Multiple proinflammatory comorbid conditions influence the pathogenesis of HFpEF and CKD. Renal dysfunction in HFpEF is a consequence of the complex interplay between hemodynamic factors, systemic congestion, inflammation, endothelial dysfunction, and neurohormonal mechanisms. In contrast to heart failure with reduced ejection fraction, there is a dearth of effective targeted therapies for HFpEF. Tailoring study design toward the different phenotypes and delving into their pathophysiology may be fruitful in development of effective phenotype-specific targeted pharmaceutical therapies.

Cellular and molecular pathobiology of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) affects half of all patients with heart failure worldwide, is increasing in prevalence, confers substantial morbidity and mortality, and has very few effective treatments. HFpEF is arguably the greatest unmet medical need in cardiovascular disease. Although HFpEF was initially considered to be a haemodynamic disorder characterized by hypertension, cardiac hypertrophy and diastolic dysfunction, the pandemics of obesity and diabetes mellitus have modified the HFpEF syndrome, which is now recognized to be a multisystem disorder involving the heart, lungs, kidneys, skeletal muscle, adipose tissue, vascular system, and immune and inflammatory signalling. This multiorgan involvement makes HFpEF difficult to model in experimental animals because the condition is not simply cardiac hypertrophy and hypertension with abnormal myocardial relaxation. However, new animal models involving both haemodynamic and metabolic disease, and increasing efforts to examine human pathophysiology, are revealing new signalling pathways and potential therapeutic targets. In this Review, we discuss the cellular and molecular pathobiology of HFpEF, with the major focus being on mechanisms relevant to the heart, because most research has focused on this organ. We also highlight the involvement of other important organ systems, including the lungs, kidneys and skeletal muscle, efforts to characterize patients with the use of systemic biomarkers, and ongoing therapeutic efforts. Our objective is to provide a roadmap of the signalling pathways and mechanisms of HFpEF that are being characterized and which might lead to more patient-specific therapies and improved clinical outcomes.

The Heart Failure with Preserved Ejection Fraction Conundrum-Redefining the Problem and Finding Common Ground?

PURPOSE OF REVIEW

Heart failure with preserved ejection fraction (HFpEF) or diastolic heart failure (DHF) makes up more than half of all congestive heart failure presentations (CHF). With an ageing population, the case load and the financial burden is projected to increase, even to epidemic proportions. CHF hospitalizations add too much of the financial and infrastructure strain. Unlike systolic heart failure (SHF), much is still either uncertain or unknown. Specifically, in epidemiology, the disease burden is established; however, risk factors and pathophysiological associations are less clear; diagnostic tools are based on rigid parameters without the ability to accurately monitor treatments effects and disease progression; finally, therapeutics are similar to SHF but without prognostic data for efficacy.

RECENT FINDINGS

The last several years have seen guidelines changing to account for greater epidemiological observations. Most of these remain general observation of shortness of breath symptom matched to static echocardiographic parameters. The introduction of exercise diastolic stress test has been welcome and warrants greater focus. HFpEF is likely to see new thinking in the coming decades. This review provides some of perspective on this topic.

HDAC Inhibition Reverses Preexisting Diastolic Dysfunction and Blocks Covert Extracellular Matrix Remodeling

BACKGROUND

Diastolic dysfunction (DD) is associated with the development of heart failure and contributes to the pathogenesis of other cardiac maladies, including atrial fibrillation. Inhibition of histone deacetylases (HDACs) has been shown to prevent DD by enhancing myofibril relaxation. We addressed the therapeutic potential of HDAC inhibition in a model of established DD with preserved ejection fraction.

METHODS

Four weeks after uninephrectomy and implantation with deoxycorticosterone acetate pellets, when DD was clearly evident, 1 cohort of mice was administered the clinical-stage HDAC inhibitor ITF2357/Givinostat. Echocardiography, blood pressure measurements, and end point invasive hemodynamic analyses were performed. Myofibril mechanics and intact cardiomyocyte relaxation were assessed ex vivo. Cardiac fibrosis was evaluated by picrosirius red staining and second harmonic generation microscopy of left ventricle (LV) sections, RNA sequencing of LV mRNA, mass spectrometry-based evaluation of decellularized LV biopsies, and atomic force microscopy determination of LV stiffness. Mechanistic studies were performed with primary rat and human cardiac fibroblasts.

RESULTS

HDAC inhibition normalized DD without lowering blood pressure in this model of systemic hypertension. In contrast to previous models, myofibril relaxation was unimpaired in uninephrectomy/deoxycorticosterone acetate mice. Furthermore, cardiac fibrosis was not evident in any mouse cohort on the basis of picrosirius red staining or second harmonic generation microscopy. However, mass spectrometry revealed induction in the expression of >100 extracellular matrix proteins in LVs of uninephrectomy/deoxycorticosterone acetate mice, which correlated with profound tissue stiffening based on atomic force microscopy. ITF2357/Givinostat treatment blocked extracellular matrix expansion and LV stiffening. The HDAC inhibitor was subsequently shown to suppress cardiac fibroblast activation, at least in part, by blunting recruitment of the profibrotic chromatin reader protein BRD4 (bromodomain-containing protein 4) to key gene regulatory elements.

CONCLUSIONS

These findings demonstrate the potential of HDAC inhibition as a therapeutic intervention to reverse existing DD and establish blockade of extracellular matrix remodeling as a second mechanism by which HDAC inhibitors improve ventricular filling. Our data reveal the existence of pathophysiologically relevant covert or hidden cardiac fibrosis that is below the limit of detection of histochemical stains such as picrosirius red, highlighting the need to evaluate fibrosis of the heart using diverse methodologies.

Relationship between low skeletal muscle mass, sarcopenic obesity and left ventricular diastolic dysfunction in Korean adults

BACKGROUND

Heart failure with preserved ejection fraction is an emerging global health issue attributed to an ageing population. However, the association between low skeletal muscle mass, sarcopenic obesity, and left ventricular diastolic dysfunction remains unclear. In the current study, we aimed to investigate the relationship between low skeletal muscle mass, sarcopenic obesity, and diastolic dysfunction in a large cohort of Korean adults.

METHODS

We conducted a cross-sectional study of 31 258 subjects who underwent health examinations at Samsung Medical Centre's Health Promotion Centre in Seoul, Republic of Korea. Relative skeletal muscle mass was calculated using the skeletal muscle mass index [SMI (%) = appendicular skeletal muscle mass (kg)/body weight (kg) × 100], which was estimated by bioelectrical impedance analysis. Cardiac structure and function were evaluated by echocardiography.

RESULTS

Amongst the 31 258 subjects, 3058 (9.78%) were determined to have diastolic dysfunction. The odds ratio (OR) of diastolic dysfunction was 1.56 [95% confidence interval (CI): 1.31-1.85; p for trend <0.001] for the lowest SMI tertile relative to the highest SMI tertile following multivariable adjustment. Furthermore, the risk of diastolic dysfunction was much higher in the sarcopenic obesity (OR: 1.70, 95% CI: 1.44-1.99), followed by in the obesity-only (OR: 1.40, 95% CI: 1.21-1.62), and sarcopenia-only (OR: 1.32, 95% CI: 1.08-1.61) when compared with the nonobese, nonsarcopenic group. These results remained consistent amongst the elderly (age ≥ 65 years).

CONCLUSIONS

Our findings demonstrate that lower skeletal muscle mass and sarcopenic obesity are strongly associated with diastolic dysfunction in middle-aged and older adults.

Effects of Cardiomyocyte-Specific Deletion of STAT3-A Murine Model of Heart Failure With Preserved Ejection Fraction

Aims: There is a high incidence of heart failure with preserved ejection fraction (HFpEF), but the options of treatment are limited. A new animal model of HFpEF is urgently needed for in-depth research on HFpEF. Signal transducer and activator of transcription 3 (STAT3) may affect the passive stiffness of myocardium, which determines cardiac diastolic function. We hypothesized that cardiomyocyte-specific deletion of STAT3 increases cardiac passive stiffness, which results the murine features of HFpEF. Methods and Results: Cardiomyocyte-specific deletion of STAT3 (STAT3cKO) mice was generated by the Cre/FLOXp method. The STAT3cKO mice showed heavier cardiac fibrosis and cardiac hypertrophy comparing with wild-type (WT) mice. Furthermore, STAT3cKO mice showed increased serum brain natriuretic peptide (BNP) level, and growth stimulation expressed gene 2 (ST2) level. Other indicators reflecting cardiac passive stiffness and diastolic function, including end diastolic pressure volume relation, MV A value, MV E value, E/A and E/E' had different fold changes. All these changes were accompanied by decreasing levels of protein kinase G (PKG). Bioinformatic analysis of STAT3cKO mice hearts suggested cGMP-PKG signaling pathway might participate in the pathogenesis of HFpEF by means of adjusting different biological functions. Conclusions: Cardiomyocyte-specific deletion of STAT3 results in a murine HFpEF model which imitates the clinical characteristics partly by affecting cardiac PKG levels. Better understanding of the factors influencing HFpEF may finally provided innovative therapies.

Role of comorbidities in heart failure prognosis Part 2: Chronic kidney disease, elevated serum uric acid

Despite improvements in pharmacotherapy, morbidity and mortality rates in community-based populations with chronic heart failure still remain high. The increase in medical complexity among patients with heart failure may be reflected by an increase in concomitant non-cardiovascular comorbidities, which are recognized as independent prognostic factors in this population. Heart failure and chronic kidney disease share many risk factors, and often coexist. The presence of kidney failure is associated with incremented risk of cardiovascular and non-cardiovascular mortality in heart failure patients. Chronic kidney disease is also linked with underutilization of evidence-based heart failure therapy that may reduce morbidity and mortality. More targeted therapies would be important to improve the prognosis of patients with these diseases. In recent years, serum uric acid as a determinant of cardiovascular risk has gained interest. Epidemiological, experimental and clinical data show that patients with hyperuricaemia are at increased risk of cardiac, renal and vascular damage and cardiovascular events. Moreover, elevated serum uric acid predicts worse outcome in both acute and chronic heart failure. While studies have raised the possibility of preventing heart failure through the use of uric acid lowering agents, the literature is still inconclusive on whether the reduction in uric acid will result in a measurable clinical benefit. Available evidences suggest that chronic kidney disease and elevated uric acid could worsen heart failure patients' prognosis. The aim of this review is to analyse a possible utilization of these comorbidities in risk stratification and as a therapeutic target to get a prognostic improvement in heart failure patients.

Sex-specific cardiac and vascular responses to hypertension in Chinese populations without overt cardiovascular diseases

OBJECTIVE

The aim of current study was to evaluate sex-specific cardiac and vascular responses to hypertension in Chinese populations without overt cardiovascular disease.

METHODS

This was a cross-sectional study and participants were enrolled in outpatient clinic between January 2017 and December 2019. Transthoracic echocardiographic measurements were performed to evaluate cardiac and vascular structure and function.

RESULTS

Among 486 participants, women account for 36.2% (n = 176). Compared to men, women were younger, had shorter duration of hypertension, and more likely to be abdominal obesity. Mean systolic and diastolic blood pressure (SBP and DBP) were similar, but women had higher mean pulse pressure (PP) than men. After adjustment for covariates, women had higher E/e' ratio and arterial elastance (Ea). The proportion of patients with concentric remodeling was higher in women (14.7% vs 9.5%). Increased SBP was associated with relative wall thickness (RWT), stroke volume (SV) index, E/e' ratio and Ea in both women and men, and the magnitude of the association between SBP and E/e' ratio was greater in women than in men (P_interaction = 0.04). Increased DBP was associated with RWT and Ea in both women and men with similar magnitude. Increased PP was associated with RWT, E/e' ratio and Ea in both women and men, and the magnitude of the association between PP and Ea was greater in women than in men (P_interaction = 0.03).

CONCLUSION

In conclusion, the current study indicates cardiac and vascular responses to hypertension are greater in women than in men, manifesting as an increased estimated LV filling pressure and arterial elastance in women.

Clinical implication of pulmonary hospitalization in heart failure with preserved ejection fraction: from the TOPCAT

Aims

The aim of the study was to explore the risk factors and evaluate the prognostic implication of pulmonary hospitalization on heart failure (HF) with preserved ejection fraction (HFpEF).

Methods and results

We performed a secondary analysis of the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist Trial (TOPCAT). A total of 1714 patients with HFpEF were analysed in our study. In the multivariate Cox proportional hazards regression analysis, history of chronic obstructive pulmonary disease (COPD), smoking, bone fracture after the age of 45, and previous HF hospitalization were identified as independent risk factors for pulmonary hospitalization. To evaluate the prognostic significance of pulmonary hospitalization, patients were categorized into five groups according to the causes of their first hospitalization. The all‐cause and cardiovascular (CV) mortality risks in these five groups were compared using time‐varying Cox proportional hazards model. Compared with patients without hospitalization during follow‐up, those with pulmonary hospitalization were associated with a 204% increase [hazard ratio (HR) 3.04, 95% confidence interval (CI) 2.07–4.47, P < 0.001] and 164% increase (HR 2.64, 95% CI 1.60–4.36, P < 0.001) in risks of all‐cause and CV mortality, respectively, while the corresponding risk increases associated with HF hospitalization were 146% (HR 2.46, 95% CI 1.74–3.48, P < 0.001) for all‐cause mortality and 186% (HR 2.86, 95% CI 1.87–4.36, P < 0.001) for CV mortality.

Conclusions

Pulmonary hospitalization was associated with a significant increase in risks of all‐cause and CV mortality, which was comparable with that associated with HF hospitalization. The results suggested that pulmonary hospitalization could be another important clinical endpoint of HFpEF.

Lower Rates of Heart Failure and All-Cause Hospitalizations During Pulmonary Artery Pressure-Guided Therapy for Ambulatory Heart Failure: One-Year Outcomes From the CardioMEMS Post-Approval Study

Supplemental Digital Content is available in the text.

Ambulatory hemodynamic monitoring with an implantable pulmonary artery (PA) sensor is approved for patients with New York Heart Association Class III heart failure (HF) and a prior HF hospitalization (HFH) within 12 months. The objective of this study was to assess the efficacy and safety of PA pressure-guided therapy in routine clinical practice with special focus on subgroups defined by sex, race, and ejection fraction.

Roles of arterial pressure volume index and arterial velocity pulse index trajectories in risk prediction in hypertensive patients with heart failure with preserved ejection fraction

Background: Arterial pressure volume index (API) and arterial velocity pulse index (AVI) contribute to the development of vascular damage and cardiovascular disease. However, the relationship between common API/AVI trajectories and cardiovascular outcomes in hypertensive patients with heart failure with preserved ejection fraction (HFpEF) is unknown.Methods: A total of 488 consecutive hypertensive patients with HFpEF who repeatedly underwent API/AVI measurements were prospectively examined. We then applied API/AVI measurements into actual clinical practice. Latent mixture modeling was performed to identify API/AVI trajectories. Hazards ratios (HRs) were measured using Cox proportional hazard models.Results: We identified four distinct API/AVI trajectory patterns: low (7.6%), moderate (43.8%), high (28.9%), and very high (19.7%). Compared with the low group, higher API trajectories were associated with increased risk of total cardiovascular events (high group, adjusted HR: 2.91, 95% confidence interval [CI]: 1.97-4.26; very high group, adjusted HR: 2.46, 95%CI: 1.18-3.79). Consistently, higher AVI trajectories were also associated with a higher risk of total cardiovascular events (high group, adjusted HR: 2.58, 95%CI: 1.23-5.47; very high group, adjusted HR: 3.12, 95%CI: 1.83-6.08), compared with the low trajectory group.Conclusion: High API/AVI trajectories are strong predictors of cardiovascular risk in hypertensive patients with HFpEF. Among these patients, measuring API/AVI may improve risk stratification and provide additional information to tailor treatment strategies.

Trajectories of Waist-to-Hip Ratio and Adverse Outcomes in Heart Failure with Mid-Range Ejection Fraction

BACKGROUND

Waist-to-hip ratio (WHR) is a strong predictor of mortality in patients with heart failure (HF). However, common WHR trajectories are not well established in HF with mid-range ejection fraction (HFmrEF) persons, and their relationship to clinical outcomes remains uncertain.

METHOD

We prospectively enrolled 1,396 participants with HFmrEF (left ventricular ejection fraction 40-49%) from April 2013 through April 2017. The waist and hip circumferences of the subjects were measured at regular intervals, and the WHR was calculated as waist circumference divided by hip circumference. Latent mixture modeling was performed to identify WHR trajectories. We then used Cox proportional-hazard models to examine the association between WHR trajectory patterns and incident HF, incident cardiovascular disease (CVD), and all-cause mortality.

RESULTS

We identified four distinct WHR trajectory patterns: lean-moderate increase (9.2%), medium-stable/increase (32.7%), heavy-stable/increase (48.0%), and heavy-moderate decrease (10.1%). After multivariable adjustment, the heavy-stable/increase and heavy-moderate decrease patterns were associated with an increased all-cause mortality risk (heavy-stable/increase: adjusted hazard ratio [HR] 3.18, 95% confidence interval [CI] 2.75-4.62; heavy-moderate decrease: adjusted HR 2.32, 95% CI 1.71-3.04), incident CVD risk (heavy-stable/increase: adjusted HR 4.03, 95% CI 2.39-4.91; heavy-moderate decrease: adjusted HR 3.05, 95% CI 2.34-4.09), and incident HF risk (heavy-stable/increase: adjusted HR 2.72, 95% CI 2.05-3.28; heavy-moderate decrease: adjusted HR 2.39, 95% CI 1.80-3.03) with reference to the lean-moderate increase pattern.

CONCLUSION

Among patients with HFmrEF, the trajectories of WHR gain are associated with poor outcomes. These findings highlight the importance of abdominal fat accumulation management during the progression of HFmrEF.

PDE1 inhibition facilitates proteasomal degradation of misfolded proteins and protects against cardiac proteinopathy

No current treatment targets cardiac proteotoxicity or can reduce mortality of heart failure (HF) with preserved ejection fraction (HFpEF). Selective degradation of misfolded proteins by the ubiquitin-proteasome system (UPS) is vital to the cell. Proteasome impairment contributes to HF. Activation of cAMP-dependent protein kinase (PKA) or cGMP-dependent protein kinase (PKG) facilitates proteasome functioning. Phosphodiesterase 1 (PDE1) hydrolyzes both cyclic nucleotides and accounts for most PDE activities in human myocardium. We report that PDE1 inhibition (IC86430) increases myocardial 26S proteasome activities and UPS proteolytic function in mice. Mice with CryAB^R120G-based proteinopathy develop HFpEF and show increased myocardial PDE1A expression. PDE1 inhibition markedly attenuates HFpEF, improves mouse survival, increases PKA-mediated proteasome phosphorylation, and reduces myocardial misfolded CryAB. Therefore, PDE1 inhibition induces PKA- and PKG-mediated promotion of proteasomal degradation of misfolded proteins and treats HFpEF caused by CryAB^R120G, representing a potentially new therapeutic strategy for HFpEF and heart disease with increased proteotoxic stress.

Influence of age and sex on left ventricular diastolic strain analysis

Speckle tracking analysis (STE) of the left ventricle offers a new method to assess left ventricular (LV) diastolic function. LV diastolic strain measurements offer a non-invasive, global and direct measure of LV diastolic function. However, there is little data on normal values and the influence of anthropomorphic factors which is crucial in clinical practice for new techniques. The aims of this study were to formulate reference values for LV diastolic strain rate, elucidate effects of age and sex on LV diastolic strain analysis and compare STE measurements with conventional LV diastolic measurements. One-hundred-forty-seven healthy subjects aged 20–72 years (≥ 28 subjects per age decade) were prospectively included (Mean age 44 ± 13.7 years, 50% female) and examined with electrocardiography and 2D-echocardiography, including speckle tracking. Left ventricular peak early diastolic strain rate (Sre) was measured in the apical windows, using STE. Men had significantly lower LV Sre values than women (1.02 ± 0.22 vs. 1.18 ± 0.23, p value < 0.001). Left ventricular Sre was inversely associated with age, with values decreasing with ageing. An inverse relation was also found with blood pressure and body surface area. Linear regression analysis showed that LV Sre was independently associated with both age and sex. A multivariable linear regression analysis for LV Sre with conventional LV diastolic variables accounted for 70.9% of the variation of LV Sre, showing good model performance. Reference values for LV Sre are reported and found to be both age- and sex-dependent. Therefore we recommend age- and sex-specific references values to be used in daily clinical practice.