Current Perspectives on Systemic Hypertension in Heart Failure with Preserved Ejection Fraction

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.

Effects of elevation of ANP and its deficiency on cardiorenal function

Atrial natriuretic peptide (ANP), encoded by Nppa, is a vasodilatory hormone that promotes salt excretion. Genome-wide association studies identified Nppa as a causative factor of blood pressure development, and in humans, ANP levels were suggested as an indicator of salt sensitivity. This study aimed to provide insights into the effects of ANP on cardiorenal function in salt-sensitive hypertension. To address this question, hypertension was induced in SSNPPA-/- (knockout of Nppa in the Dahl Salt-Sensitive (SS) rat background) or SSWT (wild type Dahl SS) rats by a high salt diet challenge (HS, 4% NaCl for 21 days). Chronic infusion of ANP in SSWT rats attenuated the increase in blood pressure and cardiorenal damage. Overall, SSNPPA-/- strain demonstrated higher blood pressure and intensified cardiac fibrosis (with no changes in ejection fraction) compared to SSWT rats. Furthermore, SSNPPA-/- rats exhibited kidney hypertrophy and higher glomerular injury scores, reduced diuresis, and lower sodium and chloride excretion than SSWT when fed a HS diet. Additionally, the activity of epithelial Na+ channel (ENaC) was found to be increased in the collecting ducts of the SSNPPA-/- rats. Taken together, these data show promise for the therapeutic benefits of ANP and ANP-increasing drugs for treating salt-sensitive hypertension.

Left ventricular geometry, tissue composition, and residual stress in High Fat Diet Dahl-Salt sensitive rats

BACKGROUND

Hypertension drives myocardial remodeling, leading to changes in structure, composition and mechanical behavior, including residual stress, which are linked to heart disease progression in a gender-specific manner. Emerging therapies are also targeting constituent-specific pathological features. All previous studies, however, have characterized remodeling in the intact tissue, rather than isolated tissue constituents, and did not include sex as a biological variable.

OBJECTIVE

In this study we first identified the contribution of collagen fiber network and myocytes to the myocardial residual stress/strain in Dahl-Salt sensitive rats fed with high fat diet. Then, we quantified the effect of hypertension on the remodeling of the left ventricle (LV), as well as the existence of sex-specific remodeling features.

METHODS

We performed mechanical tests (opening angle, ring-test) and histological analysis on isolated constituents and intact tissue of the LV. Based on the measurements from the tests, we performed a stress analysis to evaluate the residual stress distribution. Statistical analysis was performed to identify the effects of constituent isolation, elevated blood pressure, and sex of the animal on the output of both experimental measures and modeling results.

RESULTS

Hypertension leads to reduced residual stress/strain intact tissue, isolated collagen fibers, and isolated myocytes in male and female rats. Collagen remains the largest contributor to myocardial residual stress in both normotensive and hypertensive animals. We identified sex-differences in both hypertensive and normotensive animals.

CONCLUSIONS

We observed both constituent- and sex-specific remodeling features in the LV of an animal model of hypertension.

Myocardial global longitudinal strain: An early indicator of cardiac interstitial fibrosis modified by spironolactone, in a unique hypertensive rat model

OBJECTIVES

Is global longitudinal strain (GLS) a more accurate non-invasive measure of histological myocardial fibrosis than left ventricular ejection fraction (LVEF) in a hypertensive rodent model.

BACKGROUND

Hypertension results in left ventricular hypertrophy and cardiac dysfunction. Speckle-tracking echocardiography has emerged as a robust technique to evaluate cardiac function in humans compared with standard echocardiography. However, its use in animal studies is less clearly defined.

METHODS

Cyp1a1Ren2 transgenic rats were randomly assigned to three groups; normotensive, untreated hypertensive or hypertensive with daily administration of spironolactone (human equivalent dose of 50 mg/day). Cardiac function and interstitial fibrosis development were monitored for three months.

RESULTS

The lower limit of normal LVEF was calculated to be 75%. After three months hypertensive animals (196±21 mmHg systolic blood pressure (SBP)) showed increased cardiac fibrosis (8.8±3.2% compared with 2.4±0.7% % in normals), reduced LVEF (from 81±2% to 67±7%) and impaired myocardial GLS (from -17±2% to -11±2) (all p<0.001). Myocardial GLS demonstrated a stronger correlation with cardiac interstitial fibrosis (r2 = 0.58, p<0.0001) than LVEF (r2 = 0.37, p<0.006). Spironolactone significantly blunted SBP elevation (184±15, p<0.01), slowed the progression of cardiac fibrosis (4.9±1.4%, p<0.001), reduced the decline in LVEF (72±4%, p<0.05) and the degree of impaired myocardial GLS (-13±1%, p<0.01) compared to hypertensive animals.

CONCLUSIONS

This study has demonstrated that, myocardial GLS is a more accurate non-invasive measure of histological myocardial fibrosis compared to standard echocardiography, in an animal model of both treated and untreated hypertension. Spironolactone blunted the progression of cardiac fibrosis and deterioration of myocardial GLS.

Heart Failure With Preserved Ejection Fraction: Prevention and Management

Heart failure with preserved ejection fraction (HFpEF) is a complex clinical syndrome that constitutes nearly half of all heart failure cases. Because of lack of effective pharmacological targets to improve outcomes, the emphasis of the management and prevention of HFpEF should be through control of risk factors. This review will use the framework proposed by the American Heart Association on 7 simple measures ("Life's Simple 7") that involves diet and lifestyle changes to achieve ideal cardiovascular health. These 7 measures include (1) smoking, (2) obesity, (3) exercise, (4) diet, (5) blood pressure, (6) cholesterol, and (7) glucose control, which can help control the most common comorbidities and risk factors associated with HFpEF, such as hypertension, diabetes, and obesity. Therefore, application of these 7 simple measures would be a patient-centered and cost-effective way of prevention and management of HFpEF.

Anticoagulation in patients with atrial fibrillation and heart failure: Insights from the NCDR PINNACLE-AF registry

BACKGROUND

In non-valvular atrial fibrillation (NVAF) patients, congestive heart failure (CHF) confers an increased risk of stroke or systemic thromboembolism. This risk is present in both heart failure (HF) with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF). It is unclear if clinicians account for both types of CHF in their NVAF anticoagulation practices. Accordingly, we characterized current outpatient anticoagulation trends in NVAF patients with HFpEF compared to patients with HFrEF.

METHODS

The outpatient NCDR PINNACLE-AF registry was analyzed to identify patients with NVAF and CHF. The study population was subdivided into HFpEF (ie, LVEF ≥ 40%) and HFrEF (LVEF < 40%). Anticoagulation rates by CHF group were compared and stratified by CHA₂ DS₂ -VASc score.

RESULTS

A total of 340 127 patients with NVAF and CHF were identified, of whom 248 136 (73.0%) were classified as HFpEF and 91 991 (27.0%) as HFrEF. Patients with HFpEF had higher mean CHA₂ DS₂ -VASc scores and were more likely to be female, older, and have hypertension (P < 0.001). Unadjusted anticoagulation rates were significantly lower in patients with HFpEF compared to those with HFrEF (60.6% vs 64.2%, respectively). Lower rates of anticoagulation in the HFpEF group persisted after risk adjustment (RR: 0.93 [95% CI: 0.91, 0.94]). Stratification by CHA₂ DS₂ -VASc score demonstrated that lower rates of anticoagulation in patients with HFpEF persisted until a score of ≥5.

CONCLUSIONS

Patients with NVAF and HFpEF have significantly lower anticoagulation rates when compared to their HFrEF counterparts. These findings suggest a potential underappreciation of HFpEF as a risk factor in patients with NVAF.

Prevalence and distribution of left ventricular diastolic dysfunction in treated patients with long-lasting hypertension

BACKGROUND

Although the presence of sub-clinical left ventricular diastolic dysfunction (LVDD) increases cardiovascular risk, the current ESH/ESC guidelines do not include the presence of this condition in the list of target organ damage or cardiovascular risk charts dedicated to the hypertensive population. Several conditions may predict the LVDD occurrence, however, clustering of these factors with hypertension makes the relationship less clear. Therefore, the aim of this study was to evaluate both the occurrence and the severity of diastolic dysfunction in a large cohort of treated hypertensives.

METHODS

We retrospectively analyzed records of 610 hypertensive participants of the CARE NORTH Study who consented to echocardiography and were free of overt cardiovascular disease. Mean age was 54.0 ± 13.9 years (mean ± SD), BMI 29.7 ± 4.8 kg/m². The exclusion criteria were: established heart failure, LVEF <45%, coronary revascularization, valvular defect, atrial fibrillation, or stroke. The staging of LVDD was based on comprehensive transthoracic echocardiographic measurements.

RESULTS

49.7% percent of the patients had normal diastolic function (38.8% vs. 59.0%, females (F) vs. males (M), respectively; p < .001). Grade 1 LVDD was documented in 24.4% (27.8% and 21.6%; F and M; p = .08) and grade 2 LVDD in 19.3% (24.9% and 14.6%; F and M; p = .001) of the patients. None were diagnosed with grade 3 LVDD. In the logistic regression model, female sex, advancing age, obesity status, established diabetes mellitus, higher 24-hour SBP, and increasing LVMI were identified as the independent variables increasing the odds for the presence of LVDD, whereas blood-lowering therapy attenuated the risk.

CONCLUSIONS

There is an unexpectedly high prevalence of different forms of diastolic dysfunction in treated hypertensive patients who are free of overt cardiovascular disease.

Mechanisms, diagnosis, and treatment of heart failure with preserved ejection fraction and diastolic dysfunction

INTRODUCTION

Heart failure with preserved ejection fraction (HFpEF) continues to be a major challenge for clinicians. Many crucial aspects of the syndrome remain unclear, including the exact pathophysiology, early diagnosis, and treatment. Patients with HFpEF are often asymptomatic late into the disease process, and treatment with medications commonly used in heart failure with reduced ejection fraction (HFrEF) has not been proven to be beneficial. In addition, the confusion of similar terms with HFpEF, such as diastolic heart failure, and diastolic dysfunction (DD), has led to a misunderstanding of the true scope of HFpEF. Areas covered: In this review, authors highlight the differences in terminology and critically review the current knowledge on the underlying mechanisms, diagnosis, and latest treatment strategies of HFpEF. Expert commentary: While significant advances have been made in the understanding of HFpEF, the definitive diagnosis of HFpEF continues to be difficult. The development of improved and standardized methods for detecting DD has shown promise in identifying early HFpEF. However, even with early detection, there are few treatment options shown to provide mortality benefit warranting further investigation.

Rate pressure product and the components of heart rate and systolic blood pressure in hospitalized heart failure patients with preserved ejection fraction: Insights from ASCEND-HF

BACKGROUND

Heart rate and systolic blood pressure (SBP) are prognostic markers in heart failure (HF) with reduced ejection fraction (HFrEF). Their combination in rate pressure product (RPP) as well as their role in heart failure with preserved ejection fraction (HFpEF) remains unclear.

HYPOTHESIS

RPP and its components are associated with HFpEF outcomes.

METHODS

We performed an analysis of Acute Study of Clinical Effectiveness of Nesiritide in Subjects With Decompensated Heart Failure (ASCEND-HF; http://www.clinicaltrials.gov NCT00475852), which studied 7141 patients with acute HF. HFpEF was defined as left ventricular ejection fraction ≥40%. Outcomes were assessed by baseline heart rate, SBP, and RPP, as well as the change of these variables using adjusted Cox models.

RESULTS

After multivariable adjustment, in-hospital change but not baseline heart rate, SBP, and RPP were associated with 30-day mortality/HF hospitalization (hazard ratio [HR]: 1.17 per 5-bpm heart rate, HR: 1.20 per 10-mm Hg SBP, and HR: 1.02 per 100 bpm × mm Hg RPP; all P < 0.05). Baseline SBP was associated with 180-day mortality (HR: 0.88 per 10-mm Hg, P = 0.028). Though change in RPP was associated with 30-day mortality/HF hospitalization, the RPP baseline variable did not provide additional associative information with regard to outcomes when compared with assessment of baseline heart rate and SBP variables alone.

CONCLUSIONS

An increase in heart rate and SBP from baseline to discharge was associated with increased 30-day mortality/HF hospitalization in HFpEF patients with acute exacerbation. These findings suggest value in monitoring the trend of vital signs during HFpEF hospitalization.

How to Develop and Implement a Specialized Heart Failure with Preserved Ejection Fraction Clinical Program

Heart failure with preserved ejection fraction (HFpEF), a highly prevalent and complex clinical syndrome with high morbidity and mortality, is often unrecognized and not optimally treated. Clinical trials for HFpEF have been plagued by low enrollment, and clinicians often approach HFpEF patients with "therapeutic nihilism" given the perceived lack of available therapies based on the disappointing results of these prior trials. Due to these challenges, we have pioneered the successful creation of dedicated, specialized HFpEF clinical programs. Here, we discuss (1) the rationale for the development of a specialized HFpEF clinical program; (2) strategies for the systematic identification of HFpEF patients; (3) a standardized diagnostic and therapeutic approach; (4) validation of the HFpEF clinical program paradigm; (5) staffing and reimbursement considerations; (6) HFpEF clinical trial enrollment; and (7) challenges and future directions for HFpEF clinical programs. We conclude that it is feasible to create HFpEF clinical programs that fulfill the major unmet need of identifying and caring for patients with HFpEF. These clinics are essential for confirming the HFpEF diagnosis, providing standardized treatment, and facilitating clinical trial enrollment. It is our hope that the information provided here will encourage others to establish their own specialized HFpEF programs, thereby allowing for comprehensive care for these complex patients.

Can Adiponectin Help us to Target Diastolic Dysfunction?

Adiponectin is the most abundant adipokine and exhibits anti-inflammatory, antiatherogenic and antidiabetic properties. Unlike other adipokines, it inversely correlates with body weight and obesity-linked cardiovascular complications. Diastolic dysfunction is the main mechanism responsible for approximately half of all heart failure cases, the so-called heart failure with preserved ejection fraction (HFpEF), but therapeutic strategies specifically directed towards these patients are still lacking. In the last years, a link between adiponectin and diastolic dysfunction has been suggested. There are several mechanisms through which adiponectin may prevent most of the pathophysiologic mechanisms underlying diastolic dysfunction and HFpEF, including the prevention of myocardial hypertrophy, cardiac fibrosis, nitrative and oxidative stress, atherosclerosis and inflammation, while promoting angiogenesis. Thus, understanding the mechanisms underlying adiponectin-mediated improvement of diastolic function has become an exciting field of research, making adiponectin a promising therapeutic target. In this review, we explore the relevance of adiponectin signaling for the prevention of diastolic dysfunction and identify prospective therapeutic targets aiming at the treatment of this clinical condition.

Phenomapping for the Identification of Hypertensive Patients with the Myocardial Substrate for Heart Failure with Preserved Ejection Fraction

We sought to evaluate whether unbiased machine learning of dense phenotypic data ("phenomapping") could identify distinct hypertension subgroups that are associated with the myocardial substrate (i.e., abnormal cardiac mechanics) for heart failure with preserved ejection fraction (HFpEF). In the HyperGEN study, a population- and family-based study of hypertension, we studied 1273 hypertensive patients utilizing clinical, laboratory, and conventional echocardiographic phenotyping of the study participants. We used machine learning analysis of 47 continuous phenotypic variables to identify mutually exclusive groups constituting a novel classification of hypertension. The phenomapping analysis classified study participants into 2 distinct groups that differed markedly in clinical characteristics, cardiac structure/function, and indices of cardiac mechanics (e.g., phenogroup #2 had a decreased absolute longitudinal strain [12.8 ± 4.1 vs. 14.6 ± 3.5%] even after adjustment for traditional comorbidities [p < 0.001]). The 2 hypertension phenogroups may represent distinct subtypes that may benefit from targeted therapies for the prevention of HFpEF.

Current Perspectives on Left Ventricular Geometry in Systemic Hypertension

Hypertension (HTN) is a global health problem and a leading risk factor for cardiovascular disease (CVD) morbidity and mortality. The hemodynamic overload from HTN causes left ventricular (LV) remodeling, which usually manifests as distinct alterations in LV geometry, such as concentric remodeling or concentric and eccentric LV hypertrophy (LVH). In addition to being a common target organ response to HTN, LV geometric abnormalities are well-known independent risk factors for CVD. Because of their prognostic implications and quantifiable nature, changes in LV geometric parameters have commonly been included as an outcome in anti-HTN drug trials. The purpose of this paper is to review the relationship between HTN and LV geometric changes with a focus on (1) diagnostic approach, (2) epidemiology, (3) pathophysiology, (4) prognostic effect and (5) LV response to anti-HTN therapy and its impact on CVD risk reduction.

Reference ranges and determinants of right ventricle outflow tract acceleration time in healthy adults by two-dimensional echocardiography

The right ventricular outflow tract acceleration time (RVOT-AT) has shown to progressively shorten with increasing degrees of pulmonary pressure. However, the physiologic ranges of RVOT AT are based on small sample sizes and have not been investigated regarding their determining factors. The aim of this study was to investigate reference values and determining factors of RVOT-AT in a large population of healthy subjects and by values described in the literature. In the first part of the study, 1029 healthy subjects (mean age 45.6 ± 16.0 years, 565 (54.7 %) females) were prospectively assessed by clinical examination including demography, vital signs and echocardiography. In the second part, we performed a pooled analysis of eight published studies describing RVOT-AT in healthy subjects (n = 450). Statistical analysis included the calculation of 5 % quantiles for defining reference values. RVOT-AT significantly but weakly correlated with age (r: -0.207; p < 0.001), body mass Index (r: -0.16), systolic (r: -0.158) and diastolic (r: -0.137) blood pressure, heart rate (r: -0.197) and left ventricular (LV) E/A ratio (r: 0.229) (all p < 0.001). No differences were found with regards to sex. In a synopsis of both prospective and literature-based data sets, RVOT-AT weighted means was 138.51 ms and the 5 % quantile was 104.7 ms (95 % confidence interval 98.2-110.1). This study delineates the range of RVOT-AT in healthy adults and it's determining factors. Our study is in line with the cut-off value stated by the European guidelines with an RVOT-AT ≤105 ms denoting abnormal values.

Animal models of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) constitutes a clinical syndrome in which the diagnostic criteria of heart failure are not accompanied by gross disturbances of systolic function, as assessed by ejection fraction. In turn, under most circumstances, diastolic function is impaired. Although it now represents over 50 % of all patients with heart failure, the mechanisms of HFpEF remain understood, precluding effective therapy. Understanding the pathophysiology of HFpEF has been restricted by both limited access to human myocardial biopsies and by the lack of animal models that fully mimic human pathology. Animal models are valuable research tools to clarify subcellular and molecular mechanisms under conditions where the comorbidities and other confounding factors can be precisely controlled. Although most of the heart failure animal models currently available represent heart failure with reduced ejection fraction, several HFpEF animal models have been proposed. However, few of these fulfil all the features present in human disease. In this review we will provide an overview of the currently available models to study HFpEF from rodents to large animals as well as present advantages and disadvantages of these models.

Accelerated Vascular Aging as a Paradigm for Hypertensive Vascular Disease: Prevention and Therapy

Aging is considered the most important nonmodifiable risk factor for cardiovascular disease and death after age 28 years. Because of demographic changes the world population is expected to increase to 9 billion by the year 2050 and up to 12 billion by 2100, with several-fold increases among those 65 years of age and older. Healthy aging and prevention of aging-related diseases and associated health costs have become part of political agendas of governments around the world. Atherosclerotic vascular burden increases with age; accordingly, patients with progeria (premature aging) syndromes die from myocardial infarctions or stroke as teenagers or young adults. The incidence and prevalence of arterial hypertension also increases with age. Arterial hypertension-like diabetes and chronic renal failure-shares numerous pathologies and underlying mechanisms with the vascular aging process. In this article, we review how arterial hypertension resembles premature vascular aging, including the mechanisms by which arterial hypertension (as well as other risk factors such as diabetes mellitus, dyslipidemia, or chronic renal failure) accelerates the vascular aging process. We will also address the importance of cardiovascular risk factor control-including antihypertensive therapy-as a powerful intervention to interfere with premature vascular aging to reduce the age-associated prevalence of diseases such as myocardial infarction, heart failure, hypertensive nephropathy, and vascular dementia due to cerebrovascular disease. Finally, we will discuss the implementation of endothelial therapy, which aims at active patient participation to improve primary and secondary prevention of cardiovascular disease.