Biological Phenotypes of Heart Failure With Preserved Ejection Fraction

Rationale and design of the PACIFIC-PRESERVED (PhenomApping, ClassIFication and Innovation for Cardiac dysfunction in patients with heart failure and PRESERVED left ventricular ejection fraction) study

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome that is poorly defined, reflecting an incomplete understanding of its pathophysiology.

AIM

To redefine the phenotypic spectrum of HFpEF.

METHODS

The PACIFIC-PRESERVED study is a prospective multicentre cohort study designed to perform multidimensional deep phenotyping of patients diagnosed with HFpEF (left ventricular ejection fraction≥50%), patients with heart failure with reduced ejection fraction (left ventricular ejection fraction≤40%) and subjects without overt heart failure (3:2:1 ratio). The study proposes prospective investigations in patients during a 1-day hospital stay: physical examination; electrocardiogram; performance-based tests; blood samples; cardiac magnetic resonance imaging; transthoracic echocardiography (rest and low-level exercise); myocardial shear wave elastography; chest computed tomography; and non-invasive measurement of arterial stiffness. Dyspnoea, depression, general health and quality of life will be assessed by dedicated questionnaires. A biobank will be established. After the hospital stay, patients are asked to wear a connected garment (with digital sensors) to collect electrocardiography, pulmonary and activity variables in real-life conditions (for up to 14 days). Data will be centralized for machine-learning-based analyses, with the aim of reclassifying HFpEF into more distinct subgroups, improving understanding of the disease mechanisms and identifying new biological pathways and molecular targets. The study will also serve as a platform to enable the development of innovative technologies and strategies for the diagnosis and stratification of patients with HFpEF.

CONCLUSIONS

PACIFIC-PRESERVED is a prospective multicentre phenomapping study, using novel analytical techniques, which will provide a unique data resource to better define HFpEF and identify new clinically meaningful subgroups of patients.

Peripheral Blood MicroRNA-21 as a Predictive Biomarker for Heart Failure With Preserved Ejection Fraction in Old Hypertensives

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) is a major health issue with high morbidity and mortality. The epidemiology and the factors that cause HFpEF have not been fully clarified, while accurate predictive biomarkers are lacking. Our aim was to determine whether levels of microRNA-21 (miR-21) in peripheral blood monocytes, which play a critical role in many pathophysiological pathways of hypertensive heart disease, can predict the occurrence of HFpEF in older hypertensives, as well as the associated mortality and morbidity.

METHODS

We enrolled 151 elderly patients >60 years old with essential hypertension but without HF at baseline. miRs expression levels in peripheral blood mononuclear cells had been quantified by real-time reverse transcription polymerase chain reaction.

RESULTS

During a median follow-up of 8.2 years, 56 patients (37%) had an event. Levels of miR-21 in peripheral mononuclear blood cells proved to be significantly associated with the occurrence of HFpEF. More specifically, the median HFpEF-free period was 110 months for those with miR-21 >2.1 and 114 months for those with miR-21 <2.1. In addition, multivariate analysis showed that miR-21 (hazard ratio 11.14), followed by hemoglobin (Hg) (hazard ratio 0.56 for Hg >13.6 g/dl, a 45% risk reduction), were independent and the most significant predictors of HFpEF events.

CONCLUSIONS

miR-21 levels in peripheral blood monocytes are associated with the development of future HFpEF. Our findings may alter the risk models of HFpEF and support the rationale for further research into the modulation of miRs as biomarkers and treatment targets for HFpEF.

Rationale and design of the United Kingdom Heart Failure with Preserved Ejection Fraction Registry

OBJECTIVE

Heart failure with preserved ejection fraction (HFpEF) is a common heterogeneous syndrome that remains imprecisely defined and consequently has limited treatment options and poor outcomes.

METHODS

The UK Heart Failure with Preserved Ejection Fraction Registry (UK HFpEF) is a prospective data-enabled cohort and platform study. The study will develop a large, highly characterised cohort of patients with HFpEF. A biobank will be established. Deep clinical phenotyping, imaging, multiomics and centrally held national electronic health record data will be integrated at scale, in order to reclassify HFpEF into distinct subgroups, improve understanding of disease mechanisms and identify new biological pathways and molecular targets. Together, these will form the basis for developing diagnostics and targeted therapeutics specific to subgroups. It will be a platform for more effective and efficient trials, focusing on subgroups in whom targeted interventions are expected to be effective, with consent in place to facilitate rapid recruitment, and linkage for follow-up. Patients with a diagnosis of HFpEF made by a heart failure specialist, who have had natriuretic peptide levels measured and a left ventricular ejection fraction >40% are eligible. Patients with an ejection fraction between 40% and 49% will be limited to no more than 25% of the cohort.

CONCLUSIONS

UK HFpEF will develop a rich, multimodal data resource to enable the identification of disease endotypes and develop more effective diagnostic strategies, precise risk stratification and targeted therapeutics.

TRIAL REGISTRATION NUMBER

NCT05441839.

Heart Failure with Preserved Ejection Fraction: The Pathophysiological Mechanisms behind the Clinical Phenotypes and the Therapeutic Approach

Heart failure (HF) with preserved ejection fraction (HFpEF) is an increasingly frequent form and is estimated to be the dominant form of HF. On the other hand, HFpEF is a syndrome with systemic involvement, and it is characterized by multiple cardiac and extracardiac pathophysiological alterations. The increasing prevalence is currently reaching epidemic levels, thereby making HFpEF one of the greatest challenges facing cardiovascular medicine today. Compared to HF with reduced ejection fraction (HFrEF), the medical attitude in the case of HFpEF was a relaxed one towards the disease, despite the fact that it is much more complex, with many problems related to the identification of physiopathogenetic mechanisms and optimal methods of treatment. The current medical challenge is to develop effective therapeutic strategies, because patients suffering from HFpEF have symptoms and quality of life comparable to those with reduced ejection fraction, but the specific medication for HFrEF is ineffective in this situation; for this, we must first understand the pathological mechanisms in detail and correlate them with the clinical presentation. Another important aspect of HFpEF is the diversity of patients that can be identified under the umbrella of this syndrome. Thus, before being able to test and develop effective therapies, we must succeed in grouping patients into several categories, called phenotypes, depending on the pathological pathways and clinical features. This narrative review critiques issues related to the definition, etiology, clinical features, and pathophysiology of HFpEF. We tried to describe in as much detail as possible the clinical and biological phenotypes recognized in the literature in order to better understand the current therapeutic approach and the reason for the limited effectiveness. We have also highlighted possible pathological pathways that can be targeted by the latest research in this field.

Development and validation of a novel combinatorial nomogram model to predict in-hospital deaths in heart failure patients

BACKGROUND

The purpose of this study was to develop a Nomogram model to identify the risk of all-cause mortality during hospitalization in patients with heart failure (HF).

METHODS

HF patients who had been registered in the Medical Information Mart for Intensive Care (MIMIC) III and IV databases were included. The primary outcome was the occurrence of all-cause mortality during hospitalization. Two Logistic Regression models (LR1 and LR2) were developed to predict in-hospital death for HF patients from the MIMIC-IV database. The MIMIC-III database were used for model validation. The area under the receiver operating characteristic curve (AUC) was used to compare the discrimination of each model. Calibration curve was used to assess the fit of each developed models. Decision curve analysis (DCA) was used to estimate the net benefit of the predictive model.

RESULTS

A total of 16,908 HF patients were finally enrolled through screening, of whom 2,283 (13.5%) presented with in-hospital death. Totally, 48 variables were included and analyzed in the univariate and multifactorial regression analysis. The AUCs for the LR1 and LR2 models in the test cohort were 0.751 (95% CI: 0.735∼0.767) and 0.766 (95% CI: 0.751-0.781), respectively. Both LR models performed well in the calibration curve and DCA process. Nomogram and online risk assessment system were used as visualization of predictive models.

CONCLUSION

A new risk prediction tool and an online risk assessment system were developed to predict mortality in HF patients, which performed well and might be used to guide clinical practice.

Fibroblast activation protein: Pivoting cancer/chemotherapeutic insight towards heart failure

An important mechanism for cancer progression is degradation of the extracellular matrix (ECM) which is accompanied by the emergence and proliferation of an activated fibroblast, termed the cancer associated fibroblast (CAF). More specifically, an enzyme pathway identified to be amplified with local cancer progression and proliferation of the CAF, is fibroblast activation protein (FAP). The development and progression of heart failure (HF) irrespective of the etiology is associated with left ventricular (LV) remodeling and changes in ECM structure and function. As with cancer, HF progression is associated with a change in LV myocardial fibroblast growth and function, and expresses a protein signature not dissimilar to the CAF. The overall goal of this review is to put forward the postulate that scientific discoveries regarding FAP in cancer as well as the development of specific chemotherapeutics could be pivoted to target the emergence of FAP in the activated fibroblast subtype and thus hold translationally relevant diagnostic and therapeutic targets in HF.

State-of-the-art document on optimal contemporary management of cardiomyopathies

Cardiomyopathies represent significant contributors to cardiovascular morbidity and mortality. Over the past decades, a progress has occurred in characterization of the genetic background and major pathophysiological mechanisms, which has been incorporated into a more nuanced diagnostic approach and risk stratification. Furthermore, medications targeting core disease processes and/or their downstream adverse effects have been introduced for several cardiomyopathies. Combined with standard care and prevention of sudden cardiac death, these novel and emerging targeted therapies offer a possibility of improving the outcomes in several cardiomyopathies. Therefore, the aim of this document is to summarize practical approaches to the treatment of cardiomyopathies, which includes the evidence-based novel therapeutic concepts and established principles of care, tailored to the individual patient aetiology and clinical presentation of the cardiomyopathy. The scope of the document encompasses contemporary treatment of dilated, hypertrophic, restrictive and arrhythmogenic cardiomyopathy. It was based on an expert consensus reached at the Heart Failure Association online Workshop, held on 18 March 2021.

Targeting Collagen Pathways as an HFpEF Therapeutic Strategy

Heart failure with preserved ejection fraction (HFpEF) is a complex and heterogeneous clinical syndrome. The prevalence is expected to increase in the coming years, resulting in heart failure with reduced ejection fraction (HFrEF). This condition poses a burden to the global health care system as the number of patients affected by this condition is constantly increasing due to a rising average lifespan. The absence of validated drugs effective in reducing hospitalization rates and mortality may reflect the impossibility of applying a one size fits all approach as in HFrEF, heading for a personalized approach. Available evidence demonstrated the link between collagen quantity and quality alterations, and cardiac remodeling. In the context of fibrosis, collagen cross-linking is strictly involved, displaying two types of mechanisms: enzymatic and non-enzymatic. In the murine model, enzymatic inhibition of fibrosis-inducing protease-activated receptor-1 (PAR1) and transforming growth factor (TGF)-β signaling appeared to reduce cardiac fibrosis. On the other hand, in the case of non-enzymatic cross-linking, sodium glucose co-transporter type 2 inhibitors (SGLT2is), appeared to counteract the deposition of advanced glycation end-products (AGEs), which in turn contributed to ventricular remodeling. In this review, we address the mechanisms associated with collagen alterations to identify potential targets of cardiac fibrosis in HFpEF patients.

Assessment of Microvascular Disease in Heart and Brain by MRI: Application in Heart Failure with Preserved Ejection Fraction and Cerebral Small Vessel Disease

The objective of this review is to investigate the commonalities of microvascular (small vessel) disease in heart failure with preserved ejection fraction (HFpEF) and cerebral small vessel disease (CSVD). Furthermore, the review aims to evaluate the current magnetic resonance imaging (MRI) diagnostic techniques for both conditions. By comparing the two conditions, this review seeks to identify potential opportunities to improve the understanding of both HFpEF and CSVD.

Heart Failure With Preserved Ejection Fraction: An Evolving Understanding

Heart failure (HF) with preserved ejection fraction (HFpEF) is a clinical syndrome in which patients have signs and symptoms of HF due to high left ventricular (LV) filling pressure despite normal or near normal LV ejection fraction. It is more common than HF with reduced ejection fraction (HFrEF), and its diagnosis and treatment are more challenging than HFrEF. Although hypertension is the primary risk factor, coronary artery disease and other comorbidities, such as atrial fibrillation (AF), diabetes, chronic kidney disease (CKD), and obesity, also play an essential role in its formation. This review summarizes current knowledge about HFpEF, its pathophysiology, clinical presentation, diagnostic challenges, current treatments, and promising novel treatments. It is essential to continue to be updated on the latest treatments for HFpEF so that patients always receive the most therapeutic treatments. The use of GnRH agonists in the management of HFpEF, infusion of Apo a-I nanoparticle, low-level transcutaneous vagal stimulation (LLTS), and estrogen only in post-menopausal women are promising strategies to prevent diastolic dysfunction and HFpEF; however, there is still no proven curative treatment for HFpEF yet.

Oxidative stress and inflammation distinctly drive molecular mechanisms of diastolic dysfunction and remodeling in female and male heart failure with preserved ejection fraction rats

Heart failure with preserved ejection fraction (HFpEF) is a complex cardiovascular insufficiency syndrome presenting with an ejection fraction (EF) of greater than 50% along with different proinflammatory and metabolic co-morbidities. Despite previous work provided key insights into our understanding of HFpEF, effective treatments are still limited. In the current study we attempted to unravel the molecular basis of sex-dependent differences in HFpEF pathology. We analyzed left ventricular samples from 1-year-old female and male transgenic (TG) rats homozygous for the rat Ren-2 renin gene (mRen2) characterized with hypertension and diastolic dysfunction and compared it to age-matched female and male wild type rats (WT) served as control. Cardiomyocytes from female and male TG rats exhibited an elevated titin-based stiffness (F_passive), which was corrected to control level upon treatment with reduced glutathione indicating titin oxidation. This was accompanied with high levels of oxidative stress in TG rats with more prominent effects in female group. In vitro supplementation with heat shock proteins (HSPs) reversed the elevated F_passive indicating restoration of their cytoprotective function. Furthermore, the TG group exhibited high levels of proinflammatory cytokines with significant alterations in apoptotic and autophagy pathways in both sexes. Distinct alterations in the expression of several proteins between both sexes suggest their differential impact on disease development and necessitate distinct treatment options. Hence, our data suggested that oxidative stress and inflammation distinctly drive diastolic dysfunction and remodeling in female and male rats with HFpEF and that the sex-dependent mechanisms contribute to HF pathology.

Tumor Necrosis Factor-α Mediates Inflammation-induced Early-Stage Left Ventricular Systolic Dysfunction

ABSTRACT

Elevated systemic inflammation contributes to pathogenesis of heart failure with preserved ejection fraction (HFpEF), but molecular mechanisms are poorly understood. Although left ventricular (LV) diastolic dysfunction is the main cause of HFpEF, subclinical systolic dysfunction also contributes. We have previously shown that rats with collagen-induced arthritis (CIA) have systemic inflammation, LV diastolic dysfunction, and that increased circulating TNF-α contributes to inflammation-induced HFpEF pathogenesis, but does not mediate LV diastolic dysfunction in CIA rats. Contribution of systemic inflammation to dysfunction of the active process of LV diastolic and systolic function are unknown. In the present study, we used the CIA rat model to investigate the effects of systemic inflammation and TNF-α blockade on systolic function, and mRNA expression of genes involved in active diastolic relaxation and of myosin heavy chain (MyHC) isoforms. Collagen inoculation and TNF-α blockade did not affect LV mRNA expression of genes that mediate active LV diastolic function. Collagen-induced inflammation impaired LV global longitudinal strain ( P = 0.03) and velocity ( P = 0.04). This impairment of systolic function was prevented by TNF-α blockade. Collagen inoculation decreased mRNA expression of α-MyHC ( Myh6, P = 0.03) and increased expression of β-MyHC ( Myh7, P = 0.0002), a marker, which is upregulated in failing hearts. TNF-α blockade prevented this MyHC isoform-switch. These results show that increased circulating TNF-α changes the relative expression of MyHC isoforms, favoring β-MyHC, which may underlie changes in contractile function that impair systolic function. Our results indicate that TNF-α initiates early-stage LV systolic, rather than LV diastolic dysfunction.

WATCH-DM risk score predicts the prognosis of diabetic phenotype patients with heart failure and preserved ejection fraction

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome. Diabetes may identify an essential phenotype that significantly affects the prognosis of these patients. The WATCH-DM risk score has been validated for predicting the risk of heart failure in outpatients with type 2 diabetes mellitus (T2DM), but its ability to predict clinical outcomes in HFpEF patients with T2DM is unknown. We aimed to assess whether this risk score could predict the prognosis of diabetic phenotype patients with heart failure and preserved ejection fraction.

METHODS

We enrolled retrospectively 414 patients with HFpEF (70.03 ± 8.654 years, 58.70% female), including 203 (49.03%) type 2 diabetics. Diabetic HFpEF patients were stratified by baseline WATCH-DM risk score.

RESULTS

Diabetic HFpEF patients exhibited a trend toward more concentric remodeling/hypertrophy than nondiabetic HFpEF patients. When analyzed as a continuous variable, per 1-point increase in the WATCH-DM risk score was associated with increased risks of all-cause death (HR 1.181), cardiovascular death (HR 1.239), any hospitalization (HR 1.082), and HF hospitalization (HR 1.097). The AUC for the WATCH-DM risk score in predicting incident cardiovascular death (0.7061, 95% CI 0.6329-0.7792) was higher than that of all-cause death, any hospitalization, or HF hospitalization.

CONCLUSIONS

As a high-risk phenotype for heart failure, diabetic HFpEF necessitates early risk stratification and specific treatment. To the best of our knowledge, the current study is the first to demonstrate that the WATCH-DM score predicts poor outcomes in diabetic HFpEF patients. Its convenience may allow for quick risk assessments in busy clinical settings.

Association between visceral adiposity index and heart failure: A cross-sectional study

BACKGROUND

Obesity is an important risk factor for heart failure (HF).

HYPOTHESIS

Visceral adiposity index (VAI) is a simple metric for assessing obesity; however, the association between VAI and risk for HF has not been studied.

METHODS

A cross-sectional study involving 28 764 participants ≥18 years of age from the National Health and Nutrition Examination Survey (NHANES), 2009-2018, in the United States was performed. VAI was calculated using body mass index (BMI), waist circumference (WC), triglycerides (TG), and high-density lipoprotein cholesterol. VAI was analyzed as a continuous and categorical variable to examine its association with HF. Subgroup analysis was also performed.

RESULTS

The highest VAI (fourth quartile [Q4]) was found among males, BMI, systolic and diastolic blood pressure, WC, hypertension, diabetes, liver disease, coronary heart disease, smoking, total cholesterol, and TG. More participants in Q4 took β-receptor blockers, angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers/angiotensin receptor-neprilysin inhibitor, calcium channel blockers, and antidiabetic and antihyperlipidemic medications. Participants with HF exhibited greater VAI. A per-unit increase in VAI resulted in a 4% increased risk for HF (odds ratio [OR] 1.04 [95% confidence interval (CI) 1.02-1.05]). After multivariable adjustment, compared with the lowest quartile, the OR for Q3 was 1.55 (95% CI 1.24-1.94). Subgroup analysis revealed no significant interactions between VAI and specific subgroups.

CONCLUSION

VAI was independently associated with the risk for HF. As a noninvasive index of visceral adiposity, VAI could be used for a "one shot" assessment of HF risk and may serve as a novel marker.

Phenomapping in heart failure with preserved ejection fraction: insights, limitations, and future directions

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous entity with complex pathophysiology and manifestations. Phenomapping is the process of applying statistical learning techniques to patient data to identify distinct subgroups based on patterns in the data. Phenomapping has emerged as a technique with potential to improve the understanding of different HFpEF phenotypes. Phenomapping efforts have been increasing in HFpEF over the past several years using a variety of data sources, clinical variables, and statistical techniques. This review summarizes methodologies and key takeaways from these studies, including consistent discriminating factors and conserved HFpEF phenotypes. We argue that phenomapping results to date have had limited implications for clinical care and clinical trials, given that the phenotypes, as currently described, are not reliably identified in each study population and may have significant overlap. We review the inherent limitations of aggregating and utilizing phenomapping results. Lastly, we discuss potential future directions, including using phenomapping to optimize the likelihood of clinical trial success or to drive discovery in mechanisms of the disease process of HFpEF.

Synthetic growth hormone-releasing hormone agonist ameliorates the myocardial pathophysiology characteristic of heart failure with preserved ejection fraction

AIMS

To test the hypothesis that the activation of the growth hormone-releasing hormone (GHRH) receptor signalling pathway within the myocardium both prevents and reverses diastolic dysfunction and pathophysiologic features consistent with heart failure with preserved ejection fraction (HFpEF). Impaired myocardial relaxation, fibrosis, and ventricular stiffness, among other multi-organ morbidities, characterize the phenotype underlying the HFpEF syndrome. Despite the rapidly increasing prevalence of HFpEF, few effective therapies have emerged. Synthetic agonists of the GHRH receptors reduce myocardial fibrosis, cardiomyocyte hypertrophy, and improve performance in animal models of ischaemic cardiomyopathy, independently of the growth hormone axis.

METHODS AND RESULTS

CD1 mice received 4- or 8-week continuous infusion of angiotensin-II (Ang-II) to generate a phenotype with several features consistent with HFpEF. Mice were administered either vehicle or a potent synthetic agonist of GHRH, MR-356 for 4-weeks beginning concurrently or 4-weeks following the initiation of Ang-II infusion. Ang-II-treated animals exhibited diastolic dysfunction, ventricular hypertrophy, interstitial fibrosis, and normal ejection fraction. Cardiomyocytes isolated from these animals exhibited incomplete relaxation, depressed contractile responses, altered myofibrillar protein phosphorylation, and disturbed calcium handling mechanisms (ex vivo). MR-356 both prevented and reversed the development of the pathological phenotype in vivo and ex vivo. Activation of the GHRH receptors increased cAMP and cGMP in cardiomyocytes isolated from control animals but only cAMP in cardiac fibroblasts, suggesting that GHRH-A exert differential effects on cardiomyocytes and fibroblasts.

CONCLUSION

These findings indicate that the GHRH receptor signalling pathway(s) represents a new molecular target to counteract dysfunctional cardiomyocyte relaxation by targeting myofilament phosphorylation and fibrosis. Accordingly, activation of GHRH receptors with potent, synthetic GHRH agonists may provide a novel therapeutic approach to management of the myocardial alterations associated with the HFpEF syndrome.

Role of Arterial Hypertension and Hypertension-Mediated Organ Damage in Cardiotoxicity of Anticancer Therapies

PURPOSE OF THE REVIEW

Arterial hypertension (AH) is the most common cardiovascular (CV) risk factor in the community and in oncologic patients. It also represents the most important CV condition predisposing to anticancer treatment-related cardiotoxicity. This risk is heightened in the presence of cardiac AH-mediated organ damage (HMOD). Influence of AH and HMOD on the development of cardiotoxicity will be reviewed, with a focus on specific scenarios and implications for management of oncologic patients.

RECENT FINDINGS

Not adequately controlled AH before or during anticancer treatments and/or development of AH during or after completion of such therapies have detrimental effects on the clinical course of oncologic patients, particularly if HMOD is present. As overlooking CV health can jeopardize the success of anticancer treatments, the goal for clinicians caring for the oncologic patient should include the treatment of AH and HMOD.

Predicting Physiological Response in Heart Failure Management: A Graph Representation Learning Approach using Electronic Health Records

Heart failure management is challenging due to the complex and heterogenous nature of its pathophysiology which makes the conventional treatments based on the "one size fits all" ideology not suitable. Coupling the longitudinal medical data with novel deep learning and network-based analytics will enable identifying the distinct patient phenotypic characteristics to help individualize the treatment regimen through the accurate prediction of the physiological response. In this study, we develop a graph representation learning framework that integrates the heterogeneous clinical events in the electronic health records (EHR) as graph format data, in which the patient-specific patterns and features are naturally infused for personalized predictions of lab test response. The framework includes a novel Graph Transformer Network that is equipped with a self-attention mechanism to model the underlying spatial interdependencies among the clinical events characterizing the cardiac physiological interactions in the heart failure treatment and a graph neural network (GNN) layer to incorporate the explicit temporality of each clinical event, that would help summarize the therapeutic effects induced on the physiological variables, and subsequently on the patient's health status as the heart failure condition progresses over time. We introduce a global attention mask that is computed based on event co-occurrences and is aggregated across all patient records to enhance the guidance of neighbor selection in graph representation learning. We test the feasibility of our model through detailed quantitative and qualitative evaluations on observational EHR data.

Heart failure with preserved ejection fraction: the role of microvascular dysfunction

Aim. To evaluate the relationship between coronary microvascular dysfunction (CMD), biomarkers of cardiac fibrosis and cardiac remodeling (soluble ST2 (sST2), fibroblast growth factor-23 (FGF-23), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), and NT-proBNP), parameters of diastolic dysfunction (DD), and the presence of heart failure with preserved ejection fraction (HFpEF) in symptomatic patients.

Materials and methods. Study participants were 59 patients with non-obstructive coronary artery disease (CAD) and preserved left ventricular ejection fraction (LVEF) of 62 (56; 67) %. Non-obstructive CAD was verified by coronary computed tomography angiography. Stress-and rest-myocardial blood flow (MBF) and coronary flow reserve (CFR) parameters were evaluated by CZT SPECT. Serum levels of cardiac biomarkers were measured by the enzyme immunoassay. Two-dimensional transthoracic echocardiography was used to assess DD parameters.

Results. Decreased CFR was defined as CFR ≤ 2. Therefore, CMD was defined as the presence of decreased CFR in the absence of flow-limiting CAD. Distribution of patients was performed by CFR values: group 1 included patients with preserved CFR (>2, n = 35), and group 2 encompassed patients with decreased CFR (≤2, n = 24). In 87.5% of cases, patients with CMD were diagnosed with HFpEF, whereas in patients with preserved CFR, heart failure was diagnosed only in 51.4% of cases (p < 0.0001). CFR values were correlated with the left atrial volume (r = –0.527; p = 0.001), E / A ratio (r = –0.321, p = 0.012), and E / e’ (r = –0.307; p = 0.021). Following the ROC analysis, the levels of sST2 ≥ 31.304 ng / ml (AUС = 0.730; р = 0.004) and NT-proBNP ≥ 0.034 pg / ml (AUС = 0.815; р = 0.034) were identified as cut-off values for the presence of CMD in patients with non-obstructive CAD.

Conclusion. The obtained data suggest that CMD may play an essential role in HFpEF. The values of CFR were correlated with DD parameters, and decreased CFR was associated with overexpression of biomarkers of cardiac fibrosis and cardiac remodeling. Serum levels of sST2 and NT-proBNP were identified as cut-off values for the presence of CMD in patients with non-obstructive CAD.

Ephrin-B1 regulates the adult diastolic function through a late postnatal maturation of cardiomyocyte surface crests

The rod-shaped adult cardiomyocyte (CM) harbors a unique architecture of its lateral surface with periodic crests, relying on the presence of subsarcolemmal mitochondria (SSM) with unknown role. Here, we investigated the development and functional role of CM crests during the postnatal period. We found in rodents that CM crest maturation occurs late between postnatal day 20 (P20) and P60 through both SSM biogenesis, swelling and crest-crest lateral interactions between adjacent CM, promoting tissue compaction. At the functional level, we showed that the P20-P60 period is dedicated to the improvement of relaxation. Interestingly, crest maturation specifically contributes to an atypical CM hypertrophy of its short axis, without myofibril addition, but relying on CM lateral stretching. Mechanistically, using constitutive and conditional CM-specific knock-out mice, we identified ephrin-B1, a lateral membrane stabilizer, as a molecular determinant of P20-P60 crest maturation, governing both the CM lateral stretch and the diastolic function, thus highly suggesting a link between crest maturity and diastole. Remarkably, while young adult CM-specific Efnb1 KO mice essentially exhibit an impairment of the ventricular diastole with preserved ejection fraction and exercise intolerance, they progressively switch toward systolic heart failure with 100% KO mice dying after 13 months, indicative of a critical role of CM-ephrin-B1 in the adult heart function. This study highlights the molecular determinants and the biological implication of a new late P20-P60 postnatal developmental stage of the heart in rodents during which, in part, ephrin-B1 specifically regulates the maturation of the CM surface crests and of the diastolic function.

Laboratory and Metabolomic Fingerprint in Heart Failure with Preserved Ejection Fraction: From Clinical Classification to Biomarker Signature

Heart failure with preserved ejection fraction (HFpEF) remains a poorly characterized syndrome with many unknown aspects related to different patient profiles, various associated risk factors and a wide range of aetiologies. It comprises several pathophysiological pathways, such as endothelial dysfunction, myocardial fibrosis, extracellular matrix deposition and intense inflammatory system activation. Until now, HFpEF has only been described with regard to clinical features and its most commonly associated risk factors, disregarding all biological mechanisms responsible for cardiovascular deteriorations. Recently, innovations in laboratory and metabolomic findings have shown that HFpEF appears to be strictly related to specific cells and molecular mechanisms' dysregulation. Indeed, some biomarkers are efficient in early identification of these processes, adding new insights into diagnosis and risk stratification. Moreover, recent advances in intermediate metabolites provide relevant information on intrinsic cellular and energetic substrate alterations. Therefore, a systematic combination of clinical imaging and laboratory findings may lead to a 'precision medicine' approach providing prognostic and therapeutic advantages. The current review reports traditional and emerging biomarkers in HFpEF and it purposes a new diagnostic approach based on integrative information achieved from risk factor burden, hemodynamic dysfunction and biomarkers' signature partnership.

Increased protein phosphatase 5 expression in inflammation-induced left ventricular dysfunction in rats

BACKGROUND

Titin phosphorylation contributes to left ventricular (LV) diastolic dysfunction. The independent effects of inflammation on the molecular pathways that regulate titin phosphorylation are unclear.

METHODS

We investigated the effects of collagen-induced inflammation and subsequent tumor necrosis factor-α (TNF-α) inhibition on mRNA expression of genes involved in regulating titin phosphorylation in 70 Sprague-Dawley rats. LV diastolic function was assessed with echocardiography. Circulating inflammatory markers were quantified by enzyme-linked immunosorbent assay and relative LV gene expression was assessed by Taqman® polymerase chain reaction. Differences in normally distributed variables between the groups were determined by two-way analysis of variance (ANOVA), followed by Tukey post-hoc tests. For non-normally distributed variables, group differences were determined by Kruskal-Wallis tests.

RESULTS

Collagen inoculation increased LV relative mRNA expression of vascular cell adhesion molecule 1 (VCAM1), pentraxin 3 (PTX3), and inducible nitric oxide synthase (iNOS) compared to controls, indicating local microvascular inflammation. Collagen inoculation decreased soluble guanylate cyclase alpha-2 (sGCα2) and soluble guanylate cyclase beta-2 (sGCβ2) expression, suggesting downregulation of nitric oxide-soluble guanylate cyclase-cyclic guanosine monophosphate (NO-sGC-cGMP) signaling. Inhibiting TNF-α prevented collagen-induced changes in VCAM1, iNOS, sGCα2 and sGCβ2 expression. Collagen inoculation increased protein phosphatase 5 (PP5) expression. Like LV diastolic dysfunction, increased PP5 expression was not prevented by TNF-α inhibition.

CONCLUSION

Inflammation-induced LV diastolic dysfunction may be mediated by a TNF-α-independent increase in PP5 expression and dephosphorylation of the N2-Bus stretch element of titin, rather than by TNF-α-induced downregulation of NO-sGC-cGMP pathway-dependent titin phosphorylation. The steady rise in number of patients with inflammation-induced diastolic dysfunction, coupled with low success rates of current therapies warrants a better understanding of the systemic signals and molecular pathways responsible for decreased titin phosphorylation in development of LV diastolic dysfunction. The therapeutic potential of inhibiting PP5 upregulation in LV diastolic dysfunction requires investigation.

An overview of mineralocorticoid receptor antagonists as a treatment option for patients with heart failure: the current state-of-the-art and future outlook

INTRODUCTION

Mineralocorticoid receptor antagonists (MRAs) improve cardiovascular outcomes in patients with heart failure. These benefits of MRAs vary in different heart failure populations based on left ventricular ejection fraction and associated comorbidities.

AREAS COVERED

We define the pharmacologic properties of MRAs and the pathophysiological rationale for their utility in heart failure. We outline the current literature on the use of MRAs in different heart failure populations, including reduced and preserved ejection fraction (HFrEF/ HFpEF), and acute heart failure decompensation. Finally, we describe the limitations of currently available data and propose future directions of study.

EXPERT OPINION

While there is strong evidence supporting the use of MRAs in HFrEF, evidence in patients with HFpEF or acute heart failure is less definitive. Comorbidities such as obesity or atrial fibrillation could be clinical modifiers of the response to MRAs and potentially alter the risk/benefit ratio in these subpopulations. Emerging evidence for new non-steroidal MRAs reveal promising preliminary results that, if confirmed in large randomized clinical trials, could favor a change in clinical practice.

Macrophage autophagy in macrophage polarization, chronic inflammation and organ fibrosis

As the essential regulators of organ fibrosis, macrophages undergo marked phenotypic and functional changes after organ injury. These changes in macrophage phenotype and function can result in maladaptive repair, causing chronic inflammation and the development of pathological fibrosis. Autophagy, a highly conserved lysosomal degradation pathway, is one of the major players to maintain the homeostasis of macrophages through clearing protein aggregates, damaged organelles, and invading pathogens. Emerging evidence has shown that macrophage autophagy plays an essential role in macrophage polarization, chronic inflammation, and organ fibrosis. Because of the high heterogeneity of macrophages in different organs, different macrophage types may play different roles in organ fibrosis. Here, we review the current understanding of the function of macrophage autophagy in macrophage polarization, chronic inflammation, and organ fibrosis in different organs, highlight the potential role of macrophage autophagy in the treatment of fibrosis. Finally, the important unresolved issues in this field are briefly discussed. A better understanding of the mechanisms that macrophage autophagy in macrophage polarization, chronic inflammation, and organ fibrosis may contribute to developing novel therapies for chronic inflammatory diseases and organ fibrosis.

Sex-specific responses to slow progressive pressure overload in a large animal model of HFpEF

Approximately 50% of all heart failure (HF) diagnoses can be classified as HF with preserved ejection fraction (HFpEF). HFpEF is more prevalent in females compared with males, but the underlying mechanisms are unknown. We previously showed that pressure overload (PO) in male felines induces a cardiopulmonary phenotype with essential features of human HFpEF. The goal of this study was to determine if slow progressive PO induces distinct cardiopulmonary phenotypes in females and males in the absence of other pathological stressors. Female and male felines underwent aortic constriction (banding) or sham surgery after baseline echocardiography, pulmonary function testing, and blood sampling. These assessments were repeated at 2 and 4 mo postsurgery to document the effects of slow progressive pressure overload. At 4 mo, invasive hemodynamic studies were also performed. Left ventricle (LV) tissue was collected for histology, myofibril mechanics, extracellular matrix (ECM) mass spectrometry, and single-nucleus RNA sequencing (snRNAseq). The induced pressure overload (PO) was not different between sexes. PO also induced comparable changes in LV wall thickness and myocyte cross-sectional area in both sexes. Both sexes had preserved ejection fraction, but males had a slightly more robust phenotype in hemodynamic and pulmonary parameters. There was no difference in LV fibrosis and ECM composition between banded male and female animals. LV snRNAseq revealed changes in gene programs of individual cell types unique to males and females after PO. Based on these results, both sexes develop cardiopulmonary dysfunction but the phenotype is somewhat less advanced in females.NEW & NOTEWORTHY We performed a comprehensive assessment to evaluate the effects of slow progressive pressure overload on cardiopulmonary function in a large animal model of heart failure with preserved ejection fraction (HFpEF) in males and females. Functional and structural assessments were performed at the organ, tissue, cellular, protein, and transcriptional levels. This is the first study to compare snRNAseq and ECM mass spectrometry of HFpEF myocardium from males and females. The results broaden our understanding of the pathophysiological response of both sexes to pressure overload. Both sexes developed a robust cardiopulmonary phenotype, but the phenotype was equal or a bit less robust in females.

The Conundrum of HFpEF Definition: Non-Invasive Assessment Uncertainties and Alternative Diagnostic Strategies

Heart failure (HF) with preserved ejection fraction (HFpEF) is a heterogeneous syndrome including several morphological phenotypes and varying pathophysiological mechanisms. The conventional classification of HF based on left ventricular ejection fraction (LVEF) has created an oversimplification in diagnostic criteria. Although LVEF is a standardized parameter easy to calculate and broadly applied in the large clinical trials, but it is erroneously considered an index of left ventricular (LV) systolic function. Indeed,  it is affected by preload and afterload and it has limitations related to reproducibility, reduced sensitivity and scarce prognostic values especially when above 50%. Notably, additional diagnostic parameters have been recently proposed in order to improve diagnostic accuracy and to homogenise the different HFpEF populations. Unfortunately, these algorithms comprise sophisticated measurements that are difficult to apply in the daily clinical practice. Additionally, the scarce diffusion of these diagnostic criteria may have led to neutral or negative results in interventional phase 3 trials . We propose changes to the current HFpEF diagnostic approach mainly based on LVEF stratification measurement aiming towards a more inclusive model taking into consideration an integrative approach starting from the main diseases responsible for cardiac dysfunction  through to cardiac structural and functional alterations. Accordingly, with recent universal HF definitions, a stepwise model could be helpful in recognizing patients with early vs. overt HFpEF by the appraisal of specific Doppler echocardiographic variables. Thus, we would encourage the application of new criteria in order to better identify the different phenotypes and to move towards more personalized medicine.

Clinical Phenotypes of Heart Failure across the spectrum of Ejection Fraction: A Cluster Analysis

INTRODUCTION

Heart failure (HF), and especially HF with preserved ejection fraction (HFpEF), remains a challenging condition to define. The heterogenous nature of this population may be related to a variety of underlying etiologies interacting myocardial dysfunction.

METHOD

Alberta HEART study was a prospective, observational cohort that enrolled participants along the spectrum of heart failure including: healthy controls, people at risk of HF, and patients with HF and preserved (HFpEF) or reduced ejection fraction (HFrEF). We aimed to explore phenotypes of patients with HF and at-risk of developing HF. Utilising 27 detailed clinical, echocardiographic and biomarker variables, latent class analysis with and without multiple imputation was undertaken to identify distinct clinical phenotypes.

RESULTS

Of 621 participants, 191 (30.8%) and 169 (27.2%) were adjudicated by cardiologists to have HFpEF and HFrEF respectively. In the overall cohort, latent class analysis identified four distinct phenotypes. Phenotype A (n=152, 24.5%) was a healthy and low risk group. Phenotype B (n=129, 20.8%) demonstrated increased left ventricular mass and end-diastolic volumes, with elevated natriuretic peptides and clinical features of congestion. Phenotype C (n=128, 20.6%) was primarily characterised by obesity (80%) and normal indexed cardiac chamber sizes, low natriuretic peptide levels and minimal features of congestion. Phenotype D (n=212, 34.1%) consisted of elderly patients with clinical features of congestions. Phenotypes B and D demonstrated the highest risk of mortality and hospitalization over a median follow-up of 3.7 years.

CONCLUSION

Phenotypes with congestive features demonstrated increased risk profiles. Heart failure is a heterogenous classification which requires further work to appropriately categorise patients based on the underlying etiology or mechanism of impairment.

Characteristics Associated With Growth Differentiation Factor 15 in Heart Failure With Preserved Ejection Fraction and the Impact of Pirfenidone

Background Growth differentiation factor 15 (GDF-15) is elevated in heart failure with preserved ejection fraction and is associated with adverse outcome, but its relationship with myocardial fibrosis and other characteristics remains unclear. We sought to evaluate the effect of pirfenidone, a novel antifibrotic agent, on GDF-15 in heart failure with preserved ejection fraction and identify characteristics that associate with GDF-15 and with change in GDF-15 over 1 year. Methods and Results Among patients enrolled (n=107) in the PIROUETTE (Pirfenidone in Patients With Heart Failure and Preserved Left Ventricular Ejection Fraction) trial, GDF-15 was measured at baseline and at prespecified time points in patients randomized (n=94) to pirfenidone or placebo. The response of GDF-15 to pirfenidone and the association with baseline patient characteristics were evaluated. Pirfenidone had no impact on circulating GDF-15 at any time point during the 52-week trial period. In multivariable analysis, male sex, diabetes, higher circulating levels of N-terminal pro-B-type natriuretic peptide, lower renal function, and shorter 6-minute walk test distance at baseline were associated with baseline log-GDF-15. Impaired global longitudinal strain at baseline was the strongest predictor of increased GDF-15 over 52 weeks. Conclusions In patients with heart failure with preserved ejection fraction, circulating levels of GDF-15 were unaffected by treatment with pirfenidone and do not appear to be determined by myocardial fibrosis. Circulating GDF-15 was associated with a spectrum of important heart failure characteristics and it may represent a marker of overall physiological disruption. Registration URL: https://clinicaltrials.gov/ct2/show/NCT02932566; Unique identifier: NCT02932566.

Current Understanding of Molecular Pathophysiology of Heart Failure With Preserved Ejection Fraction

Heart Failure (HF) is the most common cause of hospitalization in the Western societies. HF is a heterogeneous and complex syndrome that may result from any dysfunction of systolic or diastolic capacity. Abnormal diastolic left ventricular function with impaired relaxation and increased diastolic stiffness is characteristic of heart failure with preserved ejection fraction (HFpEF). HFpEF accounts for more than 50% of all cases of HF. The prevalence increases with age: from around 1% for those aged &lt;55 years to &gt;10% in those aged 70 years or over. Nearly 50% of HF patients have HFrEF and the other 50% have HFpEF/HFmrEF, mainly based on studies in hospitalized patients. The ESC Long-Term Registry, in the outpatient setting, reports that 60% have HFrEF, 24% have HFmrEF, and 16% have HFpEF. To some extent, more than 50% of HF patients are female. HFpEF is closely associated with co-morbidities, age, and gender. Epidemiological evidence suggests that HFpEF is highly represented in older obese women and proposed as ‘obese female HFpEF phenotype’. While HFrEF phenotype is more a male phenotype. In addition, metabolic abnormalities and hemodynamic perturbations in obese HFpEF patients appear to have a greater impact in women then in men (Sorimachi et al., European J of Heart Fail, 2022, 22). To date, numerous clinical trials of HFpEF treatments have produced disappointing results. This outcome suggests that a “one size fits all” approach to HFpEF may be inappropriate and supports the use of tailored, personalized therapeutic strategies with specific treatments for distinct HFpEF phenotypes. The most important mediators of diastolic stiffness are the cardiomyocytes, endothelial cells, and extracellular matrix (ECM). The complex physiological signal transduction networks that respond to the dual challenges of inflammatory and oxidative stress are major factors that promote the development of HFpEF pathologies. These signalling networks contribute to the development of the diseases. Inhibition and/or attenuation of these signalling networks also delays the onset of disease. In this review, we discuss the molecular mechanisms associated with the physiological responses to inflammation and oxidative stress and emphasize the nature of the contribution of most important cells to the development of HFpEF via increased inflammation and oxidative stress.

Heart Failure With Preserved Ejection Fraction: Heterogeneous Syndrome, Diverse Preclinical Models

Heart failure with preserved ejection fraction (HFpEF) represents one of the greatest challenges facing cardiovascular medicine today. Despite being the most common form of heart failure worldwide, there has been limited success in developing therapeutics for this syndrome. This is largely due to our incomplete understanding of the biology driving its systemic pathophysiology and the heterogeneity of clinical phenotypes, which are increasingly being recognized as distinct HFpEF phenogroups. Development of efficacious therapeutics fundamentally relies on robust preclinical models that not only faithfully recapitulate key features of the clinical syndrome but also enable rigorous investigation of putative mechanisms of disease in the context of clinically relevant phenotypes. In this review, we propose a preclinical research strategy that is conceptually grounded in model diversification and aims to better align with our evolving understanding of the heterogeneity of clinical HFpEF. Although heterogeneity is often viewed as a major obstacle in preclinical HFpEF research, we challenge this notion and argue that embracing it may be the key to demystifying its pathobiology. Here, we first provide an overarching guideline for developing HFpEF models through a stepwise approach of comprehensive cardiac and extra-cardiac phenotyping. We then present an overview of currently available models, focused on the 3 leading phenogroups, which are primarily based on aging, cardiometabolic stress, and chronic hypertension. We discuss how well these models reflect their clinically relevant phenogroup and highlight some of the more recent mechanistic insights they are providing into the complex pathophysiology underlying HFpEF.

p53-Dependent Mitochondrial Compensation in Heart Failure With Preserved Ejection Fraction

Background

Heart failure with preserved ejection fraction (HFpEF) accounts for 50% of patients with heart failure. Clinically, HFpEF prevalence shows age and gender biases. Although the majority of patients with HFpEF are elderly, there is an emergence of young patients with HFpEF. A better understanding of the underlying pathogenic mechanism is urgently needed. Here, we aimed to determine the role of aging in the pathogenesis of HFpEF.

Methods and Results

HFpEF dietary regimen (high‐fat diet + Nω‐Nitro‐L‐arginine methyl ester hydrochloride) was used to induce HFpEF in wild type and telomerase RNA knockout mice (second‐generation and third‐generation telomerase RNA component knockout), an aging murine model. First, both male and female animals develop HFpEF equally. Second, cardiac wall thickening preceded diastolic dysfunction in all HFpEF animals. Third, accelerated HFpEF onset was observed in second‐generation telomerase RNA component knockout (at 6 weeks) and third‐generation telomerase RNA component knockout (at 4 weeks) compared with wild type (8 weeks). Fourth, we demonstrate that mitochondrial respiration transitioned from compensatory state (normal basal yet loss of maximal respiratory capacity) to dysfunction (loss of both basal and maximal respiratory capacity) in a p53 dosage dependent manner. Last, using myocardial‐specific p53 knockout animals, we demonstrate that loss of p53 activation delays the development of HFpEF.

Conclusions

Here we demonstrate that p53 activation plays a role in the pathogenesis of HFpEF. We show that short telomere animals exhibit a basal level of p53 activation, mitochondria upregulate mtDNA encoded genes as a mean to compensate for blocked mitochondrial biogenesis, and loss of myocardial p53 delays HFpEF onset in high fat diet + Nω‐Nitro‐L‐arginine methyl ester hydrochloride challenged murine model.

Risk of heart failure with preserved versus reduced ejection fraction in women with breast cancer

PURPOSE

While clinical heart failure (HF) is recognized as an adverse effect from breast cancer (BC) treatment, sparse data exist on specific HF phenotypes in affected BC survivors. We examined risk of HF by left ventricular ejection fraction (LVEF) status in women with a history of BC.

METHODS

14,804 women diagnosed with all stages of invasive BC from 2005 to 2013 and with no history of HF were matched 1:5 to 74,034 women without BC on birth year, race, and ethnicity. LVEF values were extracted from echocardiography studies within 30 days before through 90 days after the HF clinical encounter. HF was stratified into HF with preserved ejection fraction (HFpEF, LVEF ≥ 45%) and HF with reduced ejection fraction (HFrEF, LVEF < 45%). Cumulative incidence rates (CIRs) were estimated with competing risk of overall death. Hazard ratios (HR) were calculated by multivariable Cox proportional hazards regression.

RESULTS

Mean time to HF diagnosis was 5.31 years (range 0.03-13.03) in cases and 5.25 years (range 0.01-12.94) in controls. 10-year CIRs were 1.2% and 0.9% for overall HF, 0.8% and 0.7% for HFpEF, and 0.4% and 0.2% for HFrEF in cases and controls, respectively. In fully adjusted models, an overall significant increased risk of HF in cases versus controls was observed (HR: 1.31, 95% CI 1.14, 1.51). The increased risk was seen for both HFrEF (HR: 1.59, 95% CI 1.22, 2.08) and HFpEF (HR: 1.22; 95% CI 1.03, 1.45).

CONCLUSION

BC survivors experienced higher risk of HF compared with women without BC, and the risk persisted across LVEF phenotypes. Systematic cardio-oncology surveillance should be considered to mitigate this risk in BC patients.

Prevalence and Prognostic Significance of Microvascular Dysfunction in Heart Failure With Preserved Ejection Fraction

BACKGROUND

The pathophysiological and clinical significance of microvascular dysfunction (MVD) in patients with heart failure with preserved ejection fraction (HFpEF) remains uncertain.

OBJECTIVES

The aim of this study was to use cardiovascular magnetic resonance to: 1) quantify coronary microvascular function; 2) examine the relationship between perfusion and fibrosis; and 3) evaluate the impact of MVD and fibrosis on long-term clinical outcomes.

METHODS

In a prospective, observational study, patients with HFpEF and control subjects underwent multiparametric cardiovascular magnetic resonance (comprising assessment of left ventricular volumetry, perfusion, and fibrosis [focal by late gadolinium enhancement and diffuse by extracellular volume]). The primary endpoint was the composite of death or hospitalization with heart failure.

RESULTS

One hundred and one patients with HFpEF (mean age 73 ± 9 years, mean ejection fraction 56% ± 5%) and 43 control subjects (mean age 73 ± 5 years, mean ejection fraction 58% ± 5%) were studied. Myocardial perfusion reserve (MPR) was lower in patients with HFpEF versus control subjects (1.74 ± 0.76 vs 2.22 ± 0.76; P = 0.001). MVD (defined as MPR <2.0) was present in 70% of patients with HFpEF (vs 48% of control subjects; P = 0.014). There was no significant linear correlation between MPR and diffuse fibrosis (r = -0.10; P = 0.473) and no difference in MPR between those with and without focal fibrosis (mean difference -0.03; 95% CI: -0.37 to 0.30). In the HFpEF group, during median follow-up of 3.1 years, there were 45 composite events. MPR was independently predictive of clinical outcome following adjustment for clinical, blood, and imaging parameters (1 SD increase: HR: 0.673 [95% CI: 0.463 to 0.978; P = 0.038]; HR: 0.694 [95% CI: 0.491 to 0.982; P = 0.039]; and HR: 0.690 [95% CI: 0.489 to 0.973; P = 0.034], respectively).

CONCLUSIONS

MVD is highly prevalent among patients with HFpEF and is an independent predictor of prognosis. The lack of correlation between MVD and fibrosis may challenge the assertion of a direct causal link between these entities. (Developing Imaging and Plasma Biomarkers in Describing Heart Failure With Preserved Ejection Fraction [DIAMONDHFpEF]; NCT03050593).

Adenoviral vectors for cardiovascular gene therapy applications: a clinical and industry perspective

Abstract

Despite the development of novel pharmacological treatments, cardiovascular disease morbidity and mortality remain high indicating an unmet clinical need. Viral gene therapy enables targeted delivery of therapeutic transgenes and represents an attractive platform for tackling acquired and inherited cardiovascular diseases in the future. Current cardiovascular gene therapy trials in humans mainly focus on improving cardiac angiogenesis and function. Encouragingly, local delivery of therapeutic transgenes utilising first-generation human adenovirus serotype (HAd)-5 is safe in the short term and has shown some efficacy in drug refractory angina pectoris and heart failure with reduced ejection fraction. Despite this success, systemic delivery of therapeutic HAd-5 vectors targeting cardiovascular tissues and internal organs is limited by negligible gene transfer to target cells, elimination by the immune system, liver sequestration, off-target effects, and episomal degradation. To circumvent these barriers, cardiovascular gene therapy research has focused on determining the safety and efficacy of rare alternative serotypes and/or genetically engineered adenoviral capsid protein-modified vectors following local or systemic delivery. Pre-clinical studies have identified several vectors including HAd-11, HAd-35, and HAd-20–42-42 as promising platforms for local and systemic targeting of vascular endothelial and smooth muscle cells. In the past, clinical gene therapy trials were often restricted by limited scale-up capabilities of gene therapy medicinal products (GTMPs) and lack of regulatory guidance. However, significant improvement of industrial GTMP scale-up and purification, development of novel producer cell lines, and issuing of GTMP regulatory guidance by national regulatory health agencies have addressed many of these challenges, creating a more robust framework for future adenoviral-based cardiovascular gene therapy. In addition, this has enabled the mass roll out of adenovirus vector-based COVID-19 vaccines.

Key messages

First-generation HAd-5 vectors are widely used in cardiovascular gene therapy.

HAd-5-based gene therapy was shown to lead to cardiac angiogenesis and improved function.

Novel HAd vectors may represent promising transgene carriers for systemic delivery.

Novel methods allow industrial scale-up of rare/genetically altered Ad serotypes.

National regulatory health agencies have issued guidance on GMP for GTMPs.

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.

Clinical Implications of Plasma Galectin-3 in Heart Failure With Preserved Ejection Fraction: A Meta-Analysis

Background

Heart failure with preserved ejection fraction (HFpEF) is an increasing public health concern. Currently, data regarding the clinical application value of plasma Galectin-3 (Gal-3) in HFpEF are contradictory. Therefore, we performed the following meta-analysis to appraise the clinical implications of serum Gal-3 in HFpEF, including its capacity to predict new-onset disease, long-term unfavorable endpoints, and the degree of cardiac structural abnormality and left ventricular diastolic dysfunction (LVDD).

Methods

PubMed, Embase, Scopus, and Web of Science were retrieved exhaustively from their inception until November 30, 2021, to obtain studies assessing the correlation between plasma Gal-3 and the clinical features of HFpEF (new-onset HFpEF, adverse outcomes, and echocardiographic parameters related to abnormal cardiac structure and LVDD).

Results

A total of 24 papers containing 27 studies were ultimately included in the present research. The results of the meta-analysis revealed that high plasma Gal-3 levels are strongly associated with the following clinical characteristics of HFpEF: (i) the increased risk of new-onset HFpEF (HR: 1.11; 95% CI: 1.04-1.19; p = 0.910, I2 = 0%; P = 0.002); (ii) the high risk of adverse outcomes of HFpEF patients [all-cause death (HR: 1.55; 95% CI: 1.27-1.87; p = 0.138, I2 = 42%; P = 0.000) and the composite events [all-cause death and HF hospitalization (HR: 1.50; 95% CI: 1.30-1.74; p = 0.001, I2 = 61%; P = 0.000) or cardiovascular (CV) death and HF hospitalization (HR: 1.71; 95% CI: 1.51-1.94; p = 0.036, I2 = 58%; P = 0.000)]; (iii) echocardiographic indices [E/e ratio (r: 0.425, 95% CI: 0.184-0.617; p = 0.000, I2 = 93%; P = 0.001) and DT (r: 0.502, 95% CI: 0.061-0.779; p = 0.001 I2 = 91%; P = 0.027)].

Conclusions

Plasma Gal-3 might be employed as an additional predictor for new-onset HFpEF, the adverse prognosis in HFpEF patients (all-cause death, the composite endpoints of all-cause death and HF hospitalization or CV death and HF hospitalization), and the severity of LVDD in HFpEF populations.

Aldosterone dysregulation predicts the risk of mortality and rehospitalization in heart failure with a preserved ejection fraction

Serum aldosterone is associated with cardiac remodeling, which contributes to morbidity and mortality in heart failure (HF); however, the prognostic value of aldosterone in HF with a preserved ejection fraction (HFpEF) is unclear. We used liquid chromatography-tandem mass spectrometry to quantify serum aldosterone in 873 patients with HFpEF in a Registry Study of Biomarkers for HF. The retrospective study was conducted at Beijing Anzhen Hospital from May 2017 to October 2019. The primary endpoint was a composite of all-cause mortality and rehospitalization for HF. Aldosterone concentrations in patients with and without events were 124.22 pmol L^-1 (interquartile range (IQR): 48.62-256.20) and 96.33 pmol L^-1 (IQR: 37.33-215.76), respectively (P=0.023). Aldosterone independently predicted all-cause mortality (adjusted hazard ratio (aHR), 1.55; 95% confidence interval (95%CI), 1.06-2.27; P=0.024) and the primary endpoint (aHR, 1.43; 95%CI, 1.11-1.85; P=0.006). Patients with high aldosterone concentrations were at higher risk of concentric remodeling (adjusted odds ratio (aOR), 1.45; 95% CI, 1.03-2.04; P=0.034). Patients with high aldosterone and B-type natriuretic peptide concentrations were at a higher risk of the primary endpoint (hazard ratio (HR), 1.85; 95%CI, 1.29-2.66; P=0.001). We conclude that elevated aldosterone is associated with a risk of rehospitalization with HF and all-cause mortality in patients with HFpEF.

Sleep and breathing disorders in heart failure

Sleep disorders are prevalent in heart failure and include insomnia, poor sleep architecture, periodic limb movements and periodic breathing, and encompass both obstructive (OSA) and central sleep apnea (CSA). Polysomnographic studies show excess light sleep and poor sleep efficiency particularly in those with heart failure. Multiple studies of consecutive patients with heart failure show that about 50% of patients suffer from either OSA or CSA. While asleep, acute pathological consequences of apneas and hypopneas include altered blood gases, sleep fragmentation, and large negative swings in intrathoracic pressure. These pathological consequences are qualitatively similar in both types of sleep apnea, though worse in OSA than CSA. Sleep apnea results in oxidative stress, inflammation, and endothelial dysfunction, best documented in OSA. Multiple studies show that both OSA and CSA are associated with excess hospital readmissions and premature mortality. However, no randomized controlled trial (RCT) has been reported for OSA, but sensitivity analysis of two randomized controlled trials has concluded that use of positive airway pressure devices is associated with excess mortality in patients with heart failure and CSA. Phrenic nerve stimulation has shown improvement in sleep apnea events and daytime sleepiness; however, no randomized controlled trials have demonstrated improvement in survival in patients with heart failure. The correct identification and treatment of heart failure patients with sleep and breathing disorders could affect the long-term outcomes of these patients.

Score and Correlation Coefficient-Based Feature Selection for Predicting Heart Failure Diagnosis by Using Machine Learning Algorithms

Cardiovascular disease (CVD) is one of the most common causes of death that kills approximately 17 million people annually. The main reasons behind CVD are myocardial infarction and the failure of the heart to pump blood normally. Doctors could diagnose heart failure (HF) through electronic medical records on the basis of patient's symptoms and clinical laboratory investigations. However, accurate diagnosis of HF requires medical resources and expert practitioners that are not always available, thus making the diagnosing challengeable. Therefore, predicting the patients' condition by using machine learning algorithms is a necessity to save time and efforts. This paper proposed a machine-learning-based approach that distinguishes the most important correlated features amongst patients' electronic clinical records. The SelectKBest function was applied with chi-squared statistical method to determine the most important features, and then feature engineering method has been applied to create new features correlated strongly in order to train machine learning models and obtain promising results. Optimised hyperparameter classification algorithms SVM, KNN, Decision Tree, Random Forest, and Logistic Regression were used to train two different datasets. The first dataset, called Cleveland, consisted of 303 records. The second dataset, which was used for predicting HF, consisted of 299 records. Experimental results showed that the Random Forest algorithm achieved accuracy, precision, recall, and F1 scores of 95%, 97.62%, 95.35%, and 96.47%, respectively, during the test phase for the second dataset. The same algorithm achieved accuracy scores of 100% for the first dataset and 97.68% for the second dataset, while 100% precision, recall, and F1 scores were reached for both datasets.

Crossroads between Estrogen Loss, Obesity, and Heart Failure with Preserved Ejection Fraction

The prevalence of obesity and heart failure with preserved ejection fraction (HFpEF) increases significantly in postmenopausal women. Although obesity is a risk factor for left ventricular diastolic dysfunction (LVDD), the mechanisms that link the cessation of ovarian hormone production, and particularly estrogens, to the development of obesity, LVDD, and HFpEF in aging females are unclear. Clinical, and epidemiologic studies show that postmenopausal women with abdominal obesity (defined by waist circumference) are at greater risk for developing HFpEF than men or women without abdominal obesity. The study presents a review of clinical data that support a mechanistic link between estrogen loss plus obesity and left ventricular remodeling with LVDD. It also seeks to discuss potential cell and molecular mechanisms for estrogen-mediated protection against adverse adipocyte cell types, tissue depots, function, and metabolism that may contribute to LVDD and HFpEF.

Associations between galectin-1, left ventricular diastolic dysfunction, and heart failure with preserved ejection fraction

BACKGROUND

Galectin-1 is a glycan-binding protein with broad anti-inflammatory properties. Left ventricular diastolic dysfunction (DD) is associated with heart failure and mortality. The pathophysiology of DD is complex and our study aimed to investigate the associations between serum galectin-1 level, DD, and heart failure with preserved ejection fraction (HFpEF).

METHODS

Patients with symptoms of angina pectoris were enrolled. Serum galectin-1 levels and echocardiography were assessed. The study endpoint was a composite of all-cause mortality or new-onset HFpEF.

RESULTS

In total, 258 patients were enrolled (63% male; mean age 68±12 years) and grouped into tertiles based on galectin-1 levels. Patients in the highest galectin-1 group had increased left ventricular mass indexes, left atrial diameters, and prevalence of DD compared to those in the lower tertiles (all p<0.05). Moreover, elevated galectin-1 levels were significantly associated with the composite endpoint (p=0.039). After adjusting for confounding factors, high galectin-1 levels remained significantly associated with DD (odds ratio 2.44, p=0.005). The Kaplan-Meier analysis revealed patients in the highest galectin-1 group had lowest cumulative survival of composite endpoint (log rank p=0.043).

CONCLUSIONS

Elevated serum galectin-1 levels were associated with DD and the composite endpoint of all-cause mortality and incident HFpEF.

Cardiovascular Prognosis in Drug-Resistant Hypertension Stratified by 24-Hour Ambulatory Blood Pressure: The JAMP Study

[Figure: see text].

Lipotoxicity: a driver of heart failure with preserved ejection fraction?

Heart failure with preserved ejection fraction (HFpEF) is a growing public health concern, with rising incidence alongside high morbidity and mortality. However, the pathophysiology of HFpEF is not yet fully understood. The association between HFpEF and the metabolic syndrome (MetS) suggests that dysregulated lipid metabolism could drive diastolic dysfunction and subsequent HFpEF. Herein we summarise recent advances regarding the pathogenesis of HFpEF in the context of MetS, with a focus on impaired lipid handling, myocardial lipid accumulation and subsequent lipotoxicity.

S-Propargyl-Cysteine Attenuates Diabetic Cardiomyopathy in db/db Mice Through Activation of Cardiac Insulin Receptor Signaling

Background: Endogenous hydrogen sulfide (H₂S) is emerging as a key signal molecule in the development of diabetic cardiomyopathy. The aim of this study was to explore the effect and underlying mechanism of S-propargyl-cysteine (SPRC), a novel modulator of endogenous H₂S, on diabetic cardiomyopathy in db/db diabetic mice.

Methods and Results: Vehicle or SPRC were orally administered to 8-month-old male db/db mice and their wild type littermate for 12 weeks. SPRC treatment ameliorated myocardial hypertrophy, fibrosis, and cardiac systolic dysfunction assessed by histopathological examinations and echocardiography. The functional improvement by SPRC was accompanied by a reduction in myocardial lipid accumulation and ameliorated plasma lipid profiles. SPRC treatment improved glucose tolerance in db/db mice, with fasting blood glucose and peripheral insulin resistance remaining unchanged. Furthermore, insulin receptor signaling involving the phosphorylation of protein kinase B (Akt/PKB) and glycogen synthase kinase 3β (GSK3β) were elevated and activated by SPRC treatment. Primary neonatal mice cardiomyocytes were cultured to explore the mechanisms of SPRC on diabetic cardiomyopathy in vitro. Consistent with the results in vivo, SPRC not only up-regulated insulin receptor signaling pathway in cardiomyocytes in dose-dependent manner in the basal state, but also relieved the suppression of insulin receptor signaling induced by high concentrations of glucose and insulin. Furthermore, SPRC also enhanced the expression of glucose transporter 4 (GLUT4) and ³H glucose uptake in cardiomyocytes.

Conclusions: In this study, we found a novel beneficial effect of SPRC on diabetic cardiomyopathy, which was associated with activation of insulin receptor signaling. SPRC may be a promising medication for diabetic cardiomyopathy in type 2 diabetes mellitus patients.

An herbal preparation ameliorates heart failure with preserved ejection fraction by alleviating microvascular endothelial inflammation and activating NO-cGMP-PKG pathway

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous disease presenting a substantial challenge to clinicians. Currently, there is no safe and efficacious HFpEF treatment. In this study, we reported a standardized herbal medicinal product, QiShenYiQi (QSYQ), that can be used in the treatment of HFpEF.

METHODS

HFpEF mice were established by infusing a combination of N^ω-nitro-L-arginine methyl ester (L-NAME) and feeding them a high-fat diet for 14 weeks. In the 10th week, the HFpEF mice were given dapagliflozin or QSYQ via oral gavage for four weeks. The blood pressure, echocardiography, hemodynamics, leukocyte infiltration, and oxidative stress in HFpEF mice were evaluated. Besides, inflammatory factors, endothelial adhesion factors, and endothelial-mesenchymal transformation (EndMT) markers were investigated.

RESULTS

QSYQ significantly attenuated concentric cardiac remodeling while improving diastolic function and left ventricular compliance in HFpEF mice. QSYQ also inhibited inflammation and immunocyte recruitment during HFpEF. The infiltration of CD8⁺, CD4⁺ T cells, and CD11b/c⁺ monocytes was substantially mitigated in the myocardium of QSYQ-treated mice. TNF-α, MCP-1, NF-κB, and NLRP3 levels also reduced after QSYQ treatment. Furthermore, QSYQ significantly reversed the elevated expression of endothelial adhesion factors and EndMT occurrence. These effects of QSYQ were demonstrated by the activation of NO-cGMP-PKG pathway and reduction of eNOS uncoupling in the HFpEF heart.

CONCLUSION

These results provide novel evidence that QSYQ treatment improves HFpEF by inhibiting microvascular endothelial inflammation and activating NO-cGMP-PKG pathway.

Pulmonary Artery Pressure Monitoring Effectively Guides Management to Reduce Heart Failure Hospitalizations in Obesity

OBJECTIVES

This study sought to determine the impact of therapy guided by pulmonary artery (PA) pressure monitoring in patients with heart failure (HF) and obesity.

BACKGROUND

Obesity is prevalent in HF and associated with volume retention, but it complicates clinical assessment of congestion.

METHODS

The CardioMEMS Post Approval Study was a prospective, multicenter, open-label trial in 1,200 patients with New York Heart Association functional class III HF and prior HF hospitalization (HFH) within 12 months. Patients with a body mass index (BMI) >35 kg/m² were required to have a chest circumference <65 inches. Therapy was guided by PA pressure monitoring at sites, and HFHs were adjudicated 1 year before implantation and throughout follow-up. This analysis stratified patients according to ejection fraction (EF) <40% or ≥40% and by BMI <35 kg/m² or ≥35 kg/m².

RESULTS

Baseline PA diastolic pressure was higher in patients with BMI ≥35 kg/m² regardless of EF, but all PA pressures were reduced at 12 months in each cohort (P < 0.0001). HFH rate was reduced by >50% in both cohorts for EF <40% (BMI <35 kg/m² [HR: 0.48; 95% CI: 0.41-0.55] and ≥35 kg/m² [HR: 0.40; 95% CI: 0.31-0.53]) and EF ≥40% (BMI <35 kg/m² [HR: 0.42; 95% CI: 0.35-0.52] and ≥35 kg/m² [HR: 0.34; 95% CI: 0.25-0.45]; P < 0.0001). There was a nonsignificant trend toward greater reduction with more obesity. The all-cause hospitalization rate was also significantly reduced during monitoring (P < 0.01).

CONCLUSIONS

Management guided by PA pressure monitoring effectively reduced pressures, HFH, and all-cause hospitalization in patients with obesity regardless of EF. (CardioMEMS HF System Post Approval Study; NCT02279888).

Device-Based Solutions to Improve Cardiac Physiology and Hemodynamics in Heart Failure With Preserved Ejection Fraction

Characterized by a rapidly increasing prevalence, elevated mortality and rehospitalization rates, and inadequacy of pharmaceutical therapies, heart failure with preserved ejection fraction (HFpEF) has motivated the widespread development of device-based solutions. HFpEF is a multifactorial disease of various etiologies and phenotypes, distinguished by diminished ventricular compliance, diastolic dysfunction, and symptoms of heart failure despite a normal ejection performance; these symptoms include pulmonary hypertension, limited cardiac reserve, autonomic imbalance, and exercise intolerance. Several types of atrial shunts, left ventricular expanders, stimulation-based therapies, and mechanical circulatory support devices are currently under development aiming to target one or more of these symptoms by addressing the associated mechanical or hemodynamic hallmarks. Although the majority of these solutions have shown promising results in clinical or preclinical studies, no device-based therapy has yet been approved for the treatment of patients with HFpEF. The purpose of this review is to discuss the rationale behind each of these devices and the findings from the initial testing phases, as well as the limitations and challenges associated with their clinical translation.