Heart failure with preserved ejection fraction: current understandings and challenges

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

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

Evaluating the Efficacy of Interatrial Shunt Devices in Heart Failure With Preserved Ejection Fraction: A Systematic Review and Meta-Analysis

Heart failure with preserved ejection fraction (HFpEF) is a prevalent and challenging condition with limited therapeutic options. This meta-analysis aims to assess the feasibility and effectiveness of interatrial shunt devices (IASD) in the treatment of HFpEF, focusing on key hemodynamic parameters and clinical outcomes. Six clinical trials, encompassing 324 patients, were included in this analysis. The results showed a significant reduction in pulmonary capillary wedge pressure (PCWP) at rest after IASD implantation, with a mean difference of 1.55 mm Hg. PCWP during exercise also exhibited a decrease, indicating improved exercise tolerance. However, there was an increase in mean right atrial pressure following IASD implantation. These findings suggest that IASD implementation can effectively lower left atrial pressure, a critical target in HFpEF management. This results in substantial clinical improvements, including enhanced New York Heart Association class, quality of life, and 6-minute walk distance. Echocardiographic assessments revealed a reduction in left ventricular end-diastolic volume index and stable right ventricular changes. The meta-analysis underscores the potential benefits of IASD in ameliorating the symptoms and clinical outcomes of HFpEF patients. The increase in mean right atrial pressure warrants further investigation into its effects on right heart function. Additionally, this analysis emphasizes the need for larger, randomized clinical trials to validate these findings and determine optimal patient selection criteria. IASD implantation holds promise as a therapeutic option for HFpEF, offering the potential to improve the quality of life and functional status of affected patients. However, further research is imperative to confirm its efficacy relative to existing treatments and to address concerns regarding its impact on right heart function. This meta-analysis contributes to a deeper understanding of IASD's role in HFpEF management.

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.

The relationship of systemic and pulmonary arterial parameters with HFpEF scores (H2 FPEF, HFA-PEFF) and diastolic dysfunction parameters in heart failure patients with preserved ejection fraction

OBJECTIVE

We aimed to show the relationship between pulmonary pulse wave transit time (pPTT), pulmonary artery stiffness (PAS), and aortic stiffness parameters measured by non-invasive methods, HFpEF patients, and HFpEF scores (H2 FPEF, HFA-PEFF).

METHOD

A total of 101 patients were included in our study, 52 of whom were HFpEF patients and 49 were control groups without heart failure. Echocardiographic parameters for PAS and pPTT were calculated, along with diastolic parameters that support the diagnosis of HFpEF. Aortic stiffness was assessed using a PWA monitor. Demographic features, laboratory findings, aortic stiffness parameters, and echocardiographic findings including pulmonary artery parameters were compared with the control group.

RESULTS

PAS, pPTT, PWV were significantly higher in the HFpEF group than in the control group (p < 0.001). PAS and pPTT correlated positively with HFpEF scores. In linear regression analysis for PAS, a directly positive correlation was found between E/e' and PAS, independent of aortic stiffness.

CONCLUSION

These parameters can be used as a predictive value in the diagnosis process of patients with suspected HFpEF. A significant relationship between PAS and ventricular stiffness (E/e') was shown independently of aortic stiffness.

PDE4D mediates impaired β-adrenergic receptor signalling in the sinoatrial node in mice with hypertensive heart disease

AIMS

The sympathetic nervous system increases HR by activating β-adrenergic receptors (β-ARs) and increasing cAMP in sinoatrial node (SAN) myocytes while phosphodiesterases (PDEs) degrade cAMP. Chronotropic incompetence, the inability to regulate heart rate (HR) in response to sympathetic nervous system activation, is common in hypertensive heart disease; however, the basis for this is poorly understood. The objective of this study was to determine the mechanisms leading to chronotropic incompetence in mice with angiotensin II (AngII)-induced hypertensive heart disease.

METHODS AND RESULTS

C57BL/6 mice were infused with saline or AngII (2.5 mg/kg/day for 3 weeks) to induce hypertensive heart disease. HR and SAN function in response to the β-AR agonist isoproterenol (ISO) were studied in vivo using telemetry and electrocardiography, in isolated atrial preparations using optical mapping, in isolated SAN myocytes using patch-clamping, and using molecular biology. AngII-infused mice had smaller increases in HR in response to physical activity and during acute ISO injection. Optical mapping of the SAN in AngII-infused mice demonstrated impaired increases in conduction velocity and altered conduction patterns in response to ISO. Spontaneous AP firing responses to ISO in isolated SAN myocytes from AngII-infused mice were impaired due to smaller increases in diastolic depolarization (DD) slope, hyperpolarization-activated current (If), and L-type Ca2+ current (ICa,L). These changes were due to increased localization of PDE4D surrounding β1- and β2-ARs in the SAN, increased SAN PDE4 activity, and reduced cAMP generation in response to ISO. Knockdown of PDE4D using a virus-delivered shRNA or inhibition of PDE4 with rolipram normalized SAN sensitivity to β-AR stimulation in AngII-infused mice.

CONCLUSIONS

AngII-induced hypertensive heart disease results in impaired HR responses to β-AR stimulation due to up-regulation of PDE4D and reduced effects of cAMP on spontaneous AP firing in SAN myocytes.

Hypertensive response to exercise, hypertension and heart failure with preserved ejection fraction (HFpEF)-a continuum of disease?

INTRODUCTION

Heart failure with preserved ejection fraction (HFpEF) has been shown to be a long-term consequence of uncontrolled arterial hypertension (aHT). Other than that, hypertensive response to exercise (HRE) precedes aHT. We aim to evaluate the available evidence for a continuum of HRE, aHT and HFpEF.

METHODS

A literature search on PubMed was conducted to assembly the most recent data on the topic. After collecting the data, a qualitative analysis was instrumented.

RESULTS

10 studies including 16,165 subjects were analyzed with respect to the association between HRE and the future risk of developing aHT. With the exception of one study, all reported on a positive association between HRE and the future development of aHT despite methodological issues related to different definitions for HRE. Furthermore, HRE was associated with an increased risk of coronary artery disease. Moreover, we analysed 6 studies including overall 1366 subjects investigating the association between HRE and HFpEF. In these studies, increased left atrial volume index (LAVI), elevated E/e' (as surrogate parameters of increased LV end-diastolic filling pressure and of diastolic dysfunction) and higher LV mass index have been proposed as independent predictor of HRE in patients with no known HFpEF diagnosis.

DISCUSSION AND CONCLUSION

The literature search revealed suggestive data on a connection of HRE, aHT and HFpEF. HRE seems to be an independent risk factor for aHT and aHT in turn is one of the main risk factors for HFpEF. However, further research is needed to improve our knowledge of a possible continuum of disease.

Right and left ventricular structures and functions in acute HFpEF: comparing the hypertensive pulmonary edema and worsening heart failure phenotypes

BACKGROUND

Limited data are available on right (RV) and left (LV) ventricular structures and functions in acute heart failure with preserved ejection fraction (AHF-pEF) presenting with hypertensive pulmonary edema (APE) versus predominant peripheral edema (peHF).

METHODS AND RESULTS

In a prospective study of consecutive patients with AHF-pEF, 80 patients met inclusion and not exclusion criteria, and underwent echocardiographic and laboratory examination in the emergency ward. The survived (94%) were re-evaluated at the discharge. At admission, systolic, diastolic, pulse blood pressure (BP), and high sensitivity troponin I were higher (all P < 0.05) with APE than with peHF while brain-type natriuretic peptide (BNP), hemoglobin and estimated glomerular filtration rate (eGFR) did not differ between the two phenotypes. LV volumes and EF were comparable between APE and peHF, but APE showed lower relative wall thickness (RWT), smaller left atrial (LA) volume, higher pulse pressure/stroke volume (PP/SV), and higher ratio between the peak velocities of the early diastolic waves sampled by traditional and tissue Doppler modality (mitral E/e', all P < 0.05). Right ventricular and atrial (RA) areas were smaller, tricuspid anular plane systolic excursion (TAPSE) and estimated pulmonary artery peak systolic pressure (sPAP) were higher with APE than with peHF (all P < 0.05) while averaged degree of severity of tricuspid insufficiency was greater with peHF than with APE. At discharge, PP/SV, mitral E/e', sPAP, RV sizes were reduced from admission in both phenotypes (all P < 0.05) and did not differ anymore between phenotypes, whereas LV EF and TAPSE did not show significant changes over time and treatments.

CONCLUSION

In AHF-pEF, at comparable BNP and LV EF, hypertensive APE showed eccentric LV geometry but smaller RV and RA sizes, and higher RV systolic function, increased LV ventricular filling and systemic arterial loads. AHF resolution abolished the differences in PP/SV and LV diastolic load between APE and peHF whereas APE remained associated with more eccentric RV and higher TAPSE.

Exploring and Identifying Prognostic Phenotypes of Patients with Heart Failure Guided by Explainable Machine Learning

Identifying patient prognostic phenotypes facilitates precision medicine. This study aimed to explore phenotypes of patients with heart failure (HF) corresponding to prognostic condition (risk of mortality) and identify the phenotype of new patients by machine learning (ML). A unsupervised ML was applied to explore phenotypes of patients in a derivation dataset (n = 562) based on their medical records. Thereafter, supervised ML models were trained on the derivation dataset to classify these identified phenotypes. Then, the trained classifiers were further validated on an independent validation dataset (n = 168). Finally, Shapley additive explanations were used to interpret decision making of phenotype classification. Three patient phenotypes corresponding to stratified mortality risk (high, low, and intermediate) were identified. Kaplan−Meier survival curves among the three phenotypes had significant difference (pairwise comparison p < 0.05). Hazard ratio of all-cause mortality between patients in phenotype 1 (n = 91; high risk) and phenotype 3 (n = 329; intermediate risk) was 2.08 (95%CI 1.29−3.37, p = 0.003), and 0.26 (95%CI 0.11−0.61, p = 0.002) between phenotype 2 (n = 142; low risk) and phenotype 3. For phenotypes classification by random forest, AUCs of phenotypes 1, 2, and 3 were 0.736 ± 0.038, 0.815 ± 0.035, and 0.721 ± 0.03, respectively, slightly better than the decision tree. Then, the classifier effectively identified the phenotypes for new patients in the validation dataset with significant difference on survival curves and hazard ratios. Finally, age and creatinine clearance rate were identified as the top two most important predictors. ML could effectively identify patient prognostic phenotypes, facilitating reasonable management and treatment considering prognostic condition.

Intrarenal modulation of NF-κB activity attenuates cardiac injury in a swine model of CKD: a renal-cardio axis

Patients with chronic kidney disease (CKD) have a high cardiovascular mortality. CKD and heart failure (HF) coexist in up to 50% of patients, and both associate with inflammation. We aimed to define the cardiac phenotype of a novel swine model of CKD and test the hypothesis that inflammation of renal origin propels the development of precursors of HF in CKD. CKD was induced in 14 pigs, which were followed for 14 wk. Renal (multidetector computed tomography) and cardiac (echocardiography) hemodynamics were quantified before and 8 wk after single intrarenal administration of placebo or a biopolymer-fused peptide inhibitor of NF-κB that blocks NF-κB activity and decreases inflammatory activity (SynB1-ELP-p50i). Blood was collected to quantify cytokines (TNF-α, monocyte chemoattractant protein-1, and interleukins), markers of inflammation (C-reactive protein), and biomarkers of HF (atrial and brain natriuretic peptides). Pigs were then euthanized, and kidneys and hearts were studied ex vivo. Normal pigs were used as time-matched controls. Renal dysfunction in CKD was accompanied by cardiac hypertrophy and fibrosis, diastolic dysfunction, increased renal and cardiac expression of TNF-α, monocyte chemoattractant protein-1, and interleukins, canonical and noncanonical mediators of NF-κB signaling, circulating inflammatory factors, and biomarkers of HF. Notably, most of these changes were improved after intrarenal SynB1-SynB1-ELP-p50i, although cardiac inflammatory signaling remained unaltered. The translational traits of this model support its use as a platform to test novel technologies to protect the kidney and heart in CKD. A targeted inhibition of renal NF-κB signaling improves renal and cardiac function, suggesting an inflammatory renal-cardio axis underlying early HF pathophysiology in CKD.NEW & NOTEWORTHY Chronic kidney disease (CKD) is a progressive disorder with high cardiovascular morbidity and mortality. This work supports the role of inflammatory cytokines of renal origin in renal-cardio pathophysiology in CKD and that the heart may be a target. Furthermore, it supports the feasibility of a new strategy in a translational fashion, using targeted inhibition of renal NF-κB signaling to offset the development of cardiac injury in CKD.

Atrial fibrillation in patients with systolic heart failure: pathophysiology mechanisms and management

Heart failure (HF) and atrial fibrillation (AF) demonstrate a constantly increasing prevalence during the 21^st century worldwide, as a result of the aging population and the successful interventions of the clinical practice in the deterioration of adverse cardiovascular outcomes. HF and AF share common risk factors and pathophysiological mechanisms, creating the base of a constant interrelation. AF impairs systolic and diastolic function, resulting in the increasing incidence of HF, whereas the structural and neurohormonal changes in HF with preserved or reduced ejection fraction increase the possibility of the AF development. The temporal relationship of the development of either condition affects the diagnostic algorithms, the prognosis and the ideal therapeutic strategy that leads to euvolaemia, management of non-cardiovascular comorbidities, control of heart rate or restoration of sinus rate, ventricular synchronization, prevention of sudden death, stroke, embolism, or major bleeding and maintenance of a sustainable quality of life. The indicated treatment for the concomitant HF and AF includes rate or/and rhythm control as well as thromboembolism prophylaxis, while the progress in the understanding of their pathophysiological interdependence and the introduction of the genetic profiling, create new paths in the diagnosis, the prognosis and the prevention of these diseases.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Meigs' syndrome mimicking heart failure with preserved ejection fraction: a case report

Background

Meigs’ syndrome is a rare disease characterized by a triad of presentations, including benign ovarian tumor, ascites, and pleural effusion. However, a clinical diagnosis of Meigs’ syndrome remains challenging because pleural and ascitic effusions can be common findings in a variety of underlying conditions. Furthermore, these findings can often be misdiagnosed as pleural and peritoneal dissemination caused by potentially malignant tumors, leading to the administration of improper treatment.

Case presentation

We described a case of an 85-year-old postmenopausal female patient with atypical Meigs’ syndrome presenting with right-sided pleural effusion, notable leg edema, and trivial ascites, which was initially mistaken as heart failure with preserved ejection fraction. However, pleural effusion was totally ineffective against diuretic therapy. Subsequently, thoracentesis yielded serosanguineous exudative effusion. Moreover, refractory pleural effusions and abdominal/pelvic computed tomography and magnetic resonance imaging findings strongly suggested bilateral malignant ovarian tumors with pleural dissemination. Repetitive negative cytological results allowed the patient to undergo bilateral salpingo-oophorectomy. Finally, a definitive diagnosis of Meigs’ syndrome was made by confirming the presence of a benign mitotically active cellular fibroma of the ovary by pathology and that pleural effusion resolved following tumor resection.

Conclusions

Our case highlights the clinical importance of assessing Meigs’ syndrome in the diagnostic workup of pleural effusion in postmenopausal female patients. Given the favorable prognosis of Meigs’ syndrome, clinicians should consider surgical resection, even with potentially malignant ovarian tumors with accompanying pleural effusion, ascites, or both.

Diabetes mellitus and risk of new-onset and recurrent heart failure: a systematic review and meta-analysis

Despite mounting evidence of the positive relationship between diabetes mellitus (DM) and heart failure (HF), the entire context of the magnitude of risk for HF in relation to DM remains insufficiently understood. The principal reason is because new‐onset HF (HF occurring in participants without a history of HF) and recurrent HF (HF re‐occurring in patients with a history of HF) are not discriminated. This meta‐analysis aims to comprehensively and separately assess the risk of new‐onset and recurrent HF depending on the presence or absence of DM. We systematically searched cohort studies that examined the relationship between DM and new‐onset or recurrent HF using EMBASE and MEDLINE (from 1 Jan 1950 to 28 Jul 2019). The risk ratio (RR) for HF in individuals with DM compared with those without DM was pooled with a random‐effects model. Seventy‐four and 38 eligible studies presented data on RRs for new‐onset and recurrent HF, respectively. For new‐onset HF, the pooled RR [95% confidence interval (CI)] of 69 studies that examined HF as a whole [i.e. combining HF with preserved ejection fraction (HFpEF) and HF with reduced ejection fraction (HFrEF)] was 2.14 (1.96–2.34). The large between‐study heterogeneity (I² = 99.7%, P < 0.001) was significantly explained by mean age [pooled RR (95% CI) 2.60 (2.38–2.84) for mean age < 60 years vs. pooled RR (95% CI) 1.95 (1.79–2.13) for mean age ≥ 60 years] (P < 0.001). Pooled RRs (95% CI) of seven and eight studies, respectively, that separately examined HFpEF and HFrEF risk were 2.22 (2.02–2.43) for HFpEF and 2.73 (2.71–2.75) for HFrEF. The risk magnitudes between HFpEF and HFrEF were not significantly different in studies that examined both HFpEF and HFrEF risks (P = 0.86). For recurrent HF, pooled RR (95% CI) of the 38 studies was 1.39 (1.33–1.45). The large between‐study heterogeneity (I² = 80.1%, P < 0.001) was significantly explained by the proportion of men [pooled RR (95% CI) 1.53 (1.40–1.68) for < 65% men vs. 1.32 (1.25–1.39) for ≥65% men (P = 0.01)] or the large pooled RR for studies of only participants with HFpEF [pooled RR (95% CI), 1.73 (1.32–2.26) (P = 0.002)]. Results indicate that DM is a significant risk factor for both new‐onset and recurrent HF. It is suggested that the risk magnitude is large for new‐onset HF especially in young populations and for recurrent HF especially in women or individuals with HFpEF. DM is associated with future HFpEF and HFrEF to the same extent.

Heart Failure with Preserved Ejection Fraction-a Concise Review

Purpose of Review

Heart failure with preserved ejection fraction (HFpEF) is a relatively new disease entity used in medical terminology; however, both the number of patients and its clinical significance are growing. HFpEF used to be seen as a mild condition; however, the symptoms and quality of life of the patients are comparable to those with reduced ejection fraction. The disease is much more complex than previously thought. In this article, information surrounding the etiology, diagnosis, prognosis, and possible therapeutic options of HFpEF are reviewed and summarized.

Recent Findings

It has recently been proposed that heart failure (HF) is rather a heterogeneous syndrome with a spectrum of overlapping and distinct characteristics. HFpEF itself can be distilled into different phenotypes based on the underlying biology. The etiological factors of HFpEF are unclear; however, systemic low-grade inflammation and microvascular damage as a consequence of comorbidities associated with endothelial dysfunction, oxidative stress, myocardial remodeling, and fibrosis are considered to play a crucial role in the pathogenesis of a disease. The H₂FPEF score and the HFpEF nomogram are recently validated highly sensitive tools employed for risk assessment of subclinical heart failure.

Summary

Despite numerous studies, there is still no evidence-based pharmacotherapy for HFpEF and the mortality and morbidity associated with HFpEF remain high. A better understanding of the etiological factors, the impact of comorbidities, the phenotypes of the disease, and implementation of machine learning algorithms may play a key role in the development of future therapeutic strategies.

Sirtuin 3, Endothelial Metabolic Reprogramming, and Heart Failure With Preserved Ejection Fraction

The incidences of heart failure with preserved ejection fraction (HFpEF) are increased in aged populations as well as diabetes and hypertension. Coronary microvascular dysfunction has contributed to the development of HFpEF. Endothelial cells (ECs) depend on glycolysis rather than oxidative phosphorylation for generating adenosine triphosphate to maintain vascular homeostasis. Glycolytic metabolism has a critical role in the process of angiogenesis, because ECs rely on the energy produced predominantly from glycolysis for migration and proliferation. Sirtuin 3 (SIRT3) is found predominantly in mitochondria and its expression declines progressively with aging, diabetes, obesity, and hypertension. Emerging evidence indicates that endothelial SIRT3 regulates a metabolic switch between glycolysis and mitochondrial respiration. SIRT3 deficiency in EC resulted in a significant decrease in glycolysis, whereas, it exhibited higher mitochondrial respiration and more prominent production of reactive oxygen species. SIRT3 deficiency also displayed striking increases in acetylation of p53, EC apoptosis, and senescence. Impairment of SIRT3-mediated EC metabolism may lead to a disruption of EC/pericyte/cardiomyocyte communications and coronary microvascular rarefaction, which promotes cardiomyocyte hypoxia, Titin-based cardiomyocyte stiffness, and myocardial fibrosis, thus leading to a diastolic dysfunction and HFpEF. This review summarizes current knowledge of SIRT3 in EC metabolic reprograming, EC/pericyte interactions, coronary microvascular dysfunction, and HFpEF.

Prognostic utility of diastolic dysfunction and speckle tracking echocardiography in heart failure with reduced ejection fraction

Aims

We hypothesized that grading of diastolic dysfunction (DDF) according to two DDF grading algorithms and strain imaging yields prognostic information on all‐cause mortality in patients with heart failure with reduced ejection fraction (HFrEF).

Methods and results

We enrolled ambulatory HFrEF (left ventricular ejection fraction < 45%; N = 1 065) patients who underwent echocardiography and speckle tracking assessment of global longitudinal strain (GLS). Patients were stratified according to DDF grades (Grades I–III) according to two contemporary DDF grading algorithms. Prognostic performance was assessed by C‐statistics. Of the originally 1 065 enrolled patients, a total of 645 (61%) patients (age: 67 ± 11 years, male: 72%, ejection fraction: 27 ± 9%) were classified according to both DDF grading algorithms. Concordance between the algorithms was moderate (kappa = 0.48) and the reclassification rate was 33%. During a median follow‐up of 3.3 years (1.9, 4.7 years), 101 (16%) died from all causes. When comparing DDF Grade I vs. Grade III, both algorithms provided prognostic information [Nagueh: (hazard ratio) HR 2.09, 95% confidence interval (CI),1.32–3.31, P = 0.002; Johansen: HR 2.47, 95% CI, 1.57–3.87, P < 0.001]. However, when comparing DDF Grade II vs. Grade III, only the Johansen algorithm yielded prognostic information (Nagueh: HR 1.04, 95% CI, 0.60–1.77, P = 0.90; Johansen: HR 2.26, 95% CI, 1.35–3.77, P = 0.002). We found no difference in prognostic performance between the two algorithms (C‐statistics: 0.604 vs. 0.623, P = 0.24). Assessed by C‐statistics, the most powerful predictors of the endpoint from the two algorithms were E/e'‐ratio (C‐statistics: 0.644), tricuspid regurgitation velocity (C‐statistics: 0.625) and E/A‐ratio (C‐statistics: 0.602). When adding GLS to a combination of these predictors, the prognostic performance increased significantly (C‐statistics: 0.705 vs. C‐statistics: 0.634, P = 0.028).

Conclusions

Evaluation of DDF in patients with HFrEF yields prognostic information on all‐cause mortality. Furthermore, adding GLS to contemporary algorithms of DDF adds novel prognostic information.

Microvascular Rarefaction and Heart Failure With Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is characterized by diastolic dysfunction and is commonly seen in the elderly and diabetic and hypertensive patients. Despite its rising prevalence, the pathophysiology of HFpEF is poorly understood and its optimal treatment remains undefined. Recent clinical studies indicate that coronary microvascular rarefaction (reduced myocardial capillary density) with reduced coronary flow reserve (CFR) is a major contributor to diastolic dysfunction in HFpEF patients. On a molecular level, endothelial cells (EC) are dependent on glycolysis for supporting their functions and vascular homeostasis. Sirtuin 3 (SIRT3) has a critical role in the regulation of endothelial glycolytic metabolism and thus affects angiogenesis. Disruption of SIRT3-mediated EC metabolism and impairment of angiogenesis may promote cardiomyocyte hypoxia and myocardial fibrosis, leading to diastolic dysfunction and HFpEF. This review summarizes current knowledge of SIRT3 in EC metabolism, coronary microvascular rarefaction and HFpEF.

Therapeutic Targets for Treatment of Heart Failure: Focus on GRKs and β-Arrestins Affecting βAR Signaling

Heart failure (HF) is a heart disease that is classified into two main types: HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF). Both types of HF lead to significant risk of mortality and morbidity. Pharmacological treatment with β-adrenergic receptor (βAR) antagonists (also called β-blockers) has been shown to reduce the overall hospitalization and mortality rates and improve the clinical outcomes in HF patients with HFrEF but not HFpEF. Although, the survival rate of patients suffering from HF continues to drop, the management of HF still faces several limitations and discrepancies highlighting the need to develop new treatment strategies. Overstimulation of the sympathetic nervous system is an adaptive neurohormonal response to acute myocardial injury and heart damage, whereas prolonged exposure to catecholamines causes defects in βAR regulation, including a reduction in the amount of βARs and an increase in βAR desensitization due to the upregulation of G protein-coupled receptor kinases (GRKs) in the heart, contributing in turn to the progression of HF. Several studies show that myocardial GRK2 activity and expression are raised in the failing heart. Furthermore, β-arrestins play a pivotal role in βAR desensitization and, interestingly, can mediate their own signal transduction without any G protein-dependent pathway involved. In this review, we provide new insight into the role of GRKs and β-arrestins on how they affect βAR signaling regarding the molecular and cellular pathophysiology of HF. Additionally, we discuss the therapeutic potential of targeting GRKs and β-arrestins for the treatment of HF.

A reference set of curated biomedical data and metadata from clinical case reports

Clinical case reports (CCRs) provide an important means of sharing clinical experiences about atypical disease phenotypes and new therapies. However, published case reports contain largely unstructured and heterogeneous clinical data, posing a challenge to mining relevant information. Current indexing approaches generally concern document-level features and have not been specifically designed for CCRs. To address this disparity, we developed a standardized metadata template and identified text corresponding to medical concepts within 3,100 curated CCRs spanning 15 disease groups and more than 750 reports of rare diseases. We also prepared a subset of metadata on reports on selected mitochondrial diseases and assigned ICD-10 diagnostic codes to each. The resulting resource, Metadata Acquired from Clinical Case Reports (MACCRs), contains text associated with high-level clinical concepts, including demographics, disease presentation, treatments, and outcomes for each report. Our template and MACCR set render CCRs more findable, accessible, interoperable, and reusable (FAIR) while serving as valuable resources for key user groups, including researchers, physician investigators, clinicians, data scientists, and those shaping government policies for clinical trials.

Left Ventricular Diastolic Dysfunction in β-Thalassemia Major with Heart Failure

We studied the clinical, electrocardiographic, echocardiographic, Doppler and T2* cardiac magnetic resonance (CMR) data of all adult β-thalassemia major (β-TM) patients with heart failure (HF) consecutively observed at our referral center of the Sicilian region between 2008 and 2016. There were 16 patients enrolled in the study. Echocardiographic examination showed that only one patient had HF with systolic dysfunction of the left ventricle (HFrEF), whereas the others had HF with preserved systolic function of the left ventricle (HFpEF). Systolic dysfunction of the right ventricle (RV) was observed in 13 cases. Furthermore, 30.0% of the patients presented T2* CMR values consistent with intermediate risk of systolic dysfunction of the left ventricle (LV) due to iron overload, whereas 70.0% had normal values. Typical electrocardiographic abnormalities (wide T wave inversion and low voltages) were observed in 11 out of 16 patients. In conclusion, in the adult β-TM patients with HF recently observed at our center, the predominant form was that with diastolic dysfunction of the LV, and with systolic dysfunction of the RV. Only 30.0% had low values of T2* CMR. Typical electrocardiographic abnormalities were found in 69.0%.

Inhibition of prolyl hydroxylases alters cell metabolism and reverses pre-existing diastolic dysfunction in mice

BACKGROUND

Diastolic dysfunction is emerging as a leading cause of heart failure in aging population. Induction of hypoxia tolerance and reprogrammed cell metabolism have emerged as novel therapeutic strategies for the treatment of cardiovascular diseases.

METHODS AND RESULTS

In the present study, we showed that deletion of sirtuin 3 (SIRT3) resulted in a diastolic dysfunction together with a significant increase in the expression of prolyl hydroxylases (PHD) 1 and 2. We further investigated the involvement of PHD in the development of diastolic dysfunction by treating the 12-14 months old mice with a PHD inhibitor, dimethyloxalylglycine (DMOG) for 2 weeks. DMOG treatment increased the expression of hypoxia-inducible factor (HIF)-1α in the endothelium of coronary arteries. This was accompanied by a significant improvement of coronary flow reserve and diastolic function. Inhibition of PHD altered endothelial metabolism by increasing glycolysis and reducing oxygen consumption. Most importantly, treatment with DMOG completely reversed the pre-existing diastolic dysfunction in the endothelial-specific SIRT3 deficient mice.

CONCLUSIONS

Our findings demonstrate that inhibition of PHD and reprogrammed cell metabolism can reverse the pre-existed diastolic dysfunction in SIRT3 deficient mice. Our study provides a potential therapeutic strategy of induction of hypoxia tolerance for patients with diastolic dysfunction associated with coronary microvascular dysfunction, especially in the aging population with reduced SIRT3.

A Feline HFpEF Model with Pulmonary Hypertension and Compromised Pulmonary Function

Heart Failure with preserved Ejection Fraction (HFpEF) represents a major public health problem. The causative mechanisms are multifactorial and there are no effective treatments for HFpEF, partially attributable to the lack of well-established HFpEF animal models. We established a feline HFpEF model induced by slow-progressive pressure overload. Male domestic short hair cats (n = 20), underwent either sham procedures (n = 8) or aortic constriction (n = 12) with a customized pre-shaped band. Pulmonary function, gas exchange, and invasive hemodynamics were measured at 4-months post-banding. In banded cats, echocardiography at 4-months revealed concentric left ventricular (LV) hypertrophy, left atrial (LA) enlargement and dysfunction, and LV diastolic dysfunction with preserved systolic function, which subsequently led to elevated LV end-diastolic pressures and pulmonary hypertension. Furthermore, LV diastolic dysfunction was associated with increased LV fibrosis, cardiomyocyte hypertrophy, elevated NT-proBNP plasma levels, fluid and protein loss in pulmonary interstitium, impaired lung expansion, and alveolar-capillary membrane thickening. We report for the first time in HFpEF perivascular fluid cuff formation around extra-alveolar vessels with decreased respiratory compliance. Ultimately, these cardiopulmonary abnormalities resulted in impaired oxygenation. Our findings support the idea that this model can be used for testing novel therapeutic strategies to treat the ever growing HFpEF population.

Endothelial specific SIRT3 deletion impairs glycolysis and angiogenesis and causes diastolic dysfunction

Endothelial glycolysis plays a critical role in the regulation of angiogenesis. We investigated the role of Sirtuin 3 (SIRT3) on endothelial cell (EC) glycolytic metabolism, angiogenesis, and diastolic function. Our aim was to test the hypothesis that loss of SIRT3 in ECs impairs endothelial glycolytic metabolism and angiogenesis and contributes to myocardial capillary rarefaction and the development of diastolic dysfunction. Using SIRT3 deficient ECs, SIRT3 was found to regulate a metabolic switch between mitochondrial respiration and glycolysis. SIRT3 knockout (KO)-ECs exhibited higher mitochondrial respiration and reactive oxygen species (ROS) formation. SIRT3 knockout (KO)-ECs exhibited a reduction in the expression of glycolytic enzyme, PFKFB3, and a fall in glycolysis and angiogenesis. Blockade of PFKFB3 reduced glycolysis and downregulated expression of VEGF and Angiopoietin-1 (Ang-1) in ECs. Deletion of SIRT3 in ECs also impaired hypoxia-induced expression of HIF-2α, VEGF, and Ang-1, as well as reduced angiogenesis. In vivo, endothelial-specific SIRT3 KO (ECKO) mice exhibited a myocardial capillary rarefaction together with a reduced coronary flow reserve (CFR) and diastolic dysfunction. Histologic study further demonstrated that knockout of SIRT3 in ECs significantly increased perivascular fibrosis in the coronary artery. These results implicate a role of SIRT3 in modulating endothelial function and cardiac function. Ablation of SIRT3 leads to impairment of EC glycolytic metabolism and angiogenic signaling, which may contribute to coronary microvascular rarefaction and diastolic dysfunction in SIRT3 ECKO mice.

Myocardial relaxation is accelerated by fast stretch, not reduced afterload

Fast relaxation of cross-bridge generated force in the myocardium facilitates efficient diastolic function. Recently published research studying mechanisms that modulate the relaxation rate has focused on molecular factors. Mechanical factors have received less attention since the 1980s when seminal work established the theory that reducing afterload accelerates the relaxation rate. Clinical trials using afterload reducing drugs, partially based on this theory, have thus far failed to improve outcomes for patients with diastolic dysfunction. Therefore, we reevaluated the protocols that suggest reducing afterload accelerates the relaxation rate and identified that myocardial relengthening was a potential confounding factor. We hypothesized that the speed of myocardial relengthening at end systole (end systolic strain rate), and not afterload, modulates relaxation rate and tested this hypothesis using electrically-stimulated trabeculae from mice, rats, and humans. We used load-clamp techniques to vary afterload and end systolic strain rate independently. Our data show that the rate of relaxation increases monotonically with end systolic strain rate but is not altered by afterload. Computer simulations mimic this behavior and suggest that fast relengthening quickens relaxation by accelerating the detachment of cross-bridges. The relationship between relaxation rate and strain rate is novel and upends the prevailing theory that afterload modifies relaxation. In conclusion, myocardial relaxation is mechanically modified by the rate of stretch at end systole. The rate of myocardial relengthening at end systole may be a new diagnostic indicator or target for treatment of diastolic dysfunction.

Targeting Obesity and Diabetes to Treat Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is a major unmet medical need that is characterized by the presence of multiple cardiovascular and non-cardiovascular comorbidities. Foremost among these comorbidities are obesity and diabetes, which are not only risk factors for the development of HFpEF, but worsen symptoms and outcome. Coronary microvascular inflammation with endothelial dysfunction is a common denominator among HFpEF, obesity, and diabetes that likely explains at least in part the etiology of HFpEF and its synergistic relationship with obesity and diabetes. Thus, pharmacological strategies to supplement nitric oxide and subsequent cyclic guanosine monophosphate (cGMP)-protein kinase G (PKG) signaling may have therapeutic promise. Other potential approaches include exercise and lifestyle modifications, as well as targeting endothelial cell mineralocorticoid receptors, non-coding RNAs, sodium glucose transporter 2 inhibitors, and enhancers of natriuretic peptide protective NO-independent cGMP-initiated and alternative signaling, such as LCZ696 and phosphodiesterase-9 inhibitors. Additionally, understanding the role of adipokines in HFpEF may lead to new treatments. Identifying novel drug targets based on the shared underlying microvascular disease process may improve the quality of life and lifespan of those afflicted with both HFpEF and obesity or diabetes, or even prevent its occurrence.

Preservation of myocardial fatty acid oxidation prevents diastolic dysfunction in mice subjected to angiotensin II infusion

RATIONALE

Diastolic dysfunction is a common feature in many heart failure patients with preserved ejection fraction and has been associated with altered myocardial metabolism in hypertensive and diabetic patients. Therefore, metabolic interventions to improve diastolic function are warranted. In mice with a germline cardiac-specific deletion of acetyl CoA carboxylase 2 (ACC2), systolic dysfunction induced by pressure-overload was prevented by maintaining cardiac fatty acid oxidation (FAO). However, it has not been evaluated whether this strategy would prevent the development of diastolic dysfunction in the adult heart.

OBJECTIVE

To test the hypothesis that augmenting cardiac FAO is protective against angiotensin II (AngII)-induced diastolic dysfunction in an adult mouse heart.

METHODS AND RESULTS

We generated a mouse model to induce cardiac-specific deletion of ACC2 in adult mice. Tamoxifen treatment (20mg/kg/day for 5days) was sufficient to delete ACC2 protein and increase cardiac FAO by 50% in ACC2 flox/flox-MerCreMer+ mice (iKO). After 4weeks of AngII (1.1mg/kg/day), delivered by osmotic mini-pumps, iKO mice showed normalized E/E' and E'/A' ratios compared to AngII treated controls (CON). The prevention of diastolic dysfunction in iKO-AngII was accompanied by maintained FAO and reduced glycolysis and anaplerosis. Furthermore, iKO-AngII hearts had a~50% attenuation of cardiac hypertrophy and fibrosis compared to CON. In addition, maintenance of FAO in iKO hearts suppressed AngII-associated increases in oxidative stress and sustained mitochondrial respiratory complex activities.

CONCLUSION

These data demonstrate that impaired FAO is a contributor to the development of diastolic dysfunction induced by AngII. Maintenance of FAO in this model leads to an attenuation of hypertrophy, reduces fibrosis, suppresses increases in oxidative stress, and maintains mitochondrial function. Therefore, targeting mitochondrial FAO is a promising therapeutic strategy for the treatment of diastolic dysfunction.

Impaired Myocardial Bioenergetics in HFpEF and the Role of Antioxidants

Heart failure with preserved ejection fraction (HFpEF) is a significant cardiovascular condition for more than 50% of patients with heart failure. Currently, there is no effective treatment to decrease morbidity and mortality rates associated with HFpEF because of its pathophysiological heterogeneity. Recent evidence shows that deficiency in myocardial bioenergetics is one of the key pathophysiological factors contributing to diastolic dysfunction in HFpEF. Another known mechanism for HFpEF is an overproduction of free radicals, specifically reactive oxygen species. To reduce free radical formation, antioxidants are often used. This article is a summative review of the recent relevant literature that addresses cardiac bioenergetics, deficiency in myocardial bioenergetics, and increased reactive oxygen species associated with HFpEF and the promising potential use of antioxidants in managing this condition.

Follistatin like 1 Regulates Hypertrophy in Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) accounts for ∼50% of all clinical presentations of heart failure, (HF) and its prevalence is expected to increase. However, there are no evidence-based therapies for HFpEF; thus, HFpEF represents a major unmet need. Although hypertension is the single most important risk factor for HFpEF, with a prevalence of 60% to 89% from clinical trials and human HF registries, blood pressure therapy alone is insufficient to prevent and treat HFpEF. Follistatin-like 1 (Fstl1), a divergent member of the follistatin family of extracellular glycoproteins, has previously been shown to be elevated in HF with reduced ejection fraction and associated with increased left ventricular mass. In this study, blood levels of Fstl1 were increased in humans with HFpEF. This increase was also evident in mice with hypertension-induced HFpEF and adult rat ventricular myocytes stimulated with aldosterone. Treatment with recombinant Fstl1 abrogated aldosterone-induced cardiac myocyte hypertrophy, suggesting a role for Fstl1 in the regulation of hypertrophy in HFpEF. There was also a reduction in the E/A ratio, a measure of diastolic dysfunction. Furthermore, HFpEF induced in a mouse model that specifically ablates Fstl1 in cardiac myocytes (cardiac myocyte-specific Fstl1 knockout [cFstl1-KO]) showed exacerbation of HFpEF with worsened diastolic dysfunction. In addition, cFstl1-KO-HFpEF mice demonstrated more marked cardiac myocyte hypertrophy with increased molecular markers of atrial natriuretic peptide and brain natriuretic peptide expression. These findings indicate that Fstl1 exerts therapeutic effects by modulating cardiac hypertrophy in HFpEF.

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Fstl1, also known as transforming growth factor-β–stimulated clone 36, is an extra-cellular glycoprotein implicated in the pathophysiology of cardiac disease.

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Fstl1 acts in a noncanonical manner relative to other follistatin family members, but its functions remain poorly understood.

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Circulating Flst1 levels are increased in humans with chronic stable HFpEF.

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Fstl1 treatment modulates cardiomyocyte hypertrophy in vitro and in vivo.

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Cardiac myocyte deletion of Fstl1 worsens the HFpEF phenotype in mice.

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These studies indicate that Fstl1 may be therapeutically effective in HFpEF by modulating cardiac hypertrophy and improving parameters of diastolic dysfunction.

Atrial Fibrillation Begets Heart Failure and Vice Versa: Temporal Associations and Differences in Preserved Versus Reduced Ejection Fraction

BACKGROUND

Atrial fibrillation (AF) and heart failure (HF) frequently coexist and together confer an adverse prognosis. The association of AF with HF subtypes has not been well described. We sought to examine differences in the temporal association of AF and HF with preserved versus reduced ejection fraction.

METHODS AND RESULTS

We studied Framingham Heart Study participants with new-onset AF or HF between 1980 and 2012. Among 1737 individuals with new AF (mean age, 75±12 years; 48% women), more than one third (37%) had HF. Conversely, among 1166 individuals with new HF (mean age, 79±11 years; 53% women), more than half (57%) had AF. Prevalent AF was more strongly associated with incident HF with preserved ejection fraction (multivariable-adjusted hazard ratio [HR], 2.34; 95% confidence interval [CI], 1.48-3.70; no AF as referent) versus HF with reduced ejection fraction (HR, 1.32; 95% CI, 0.83-2.10), with a trend toward difference between HF subtypes (P for difference=0.06). Prevalent HF was associated with incident AF (HR, 2.18; 95% CI, 1.26-3.76; no HF as referent). The presence of both AF and HF portended greater mortality risk compared with neither condition, particularly among individuals with new HF with reduced ejection fraction and prevalent AF (HR, 2.72; 95% CI, 2.12-3.48) compared with new HF with preserved ejection fraction and prevalent AF (HR, 1.83; 95% CI, 1.41-2.37; P for difference=0.02).

CONCLUSIONS

AF occurs in more than half of individuals with HF, and HF occurs in more than one third of individuals with AF. AF precedes and follows HF with both preserved and reduced ejection fraction, with some differences in temporal association and prognosis. Future studies focused on underlying mechanisms of these dual conditions are warranted.