Hemodynamic and renal excretory effects of human brain natriuretic peptide infusion in patients with congestive heart failure. A double-blind, placebo-controlled, randomized crossover trial

Renal Effects of Combination Phosphodiesterase V Inhibition and Low-Dose B-Type Natriuretic Peptide in Acute Heart Failure: A Randomized Clinical Trial

BACKGROUND

Cardiorenal dysfunction with impaired cyclic GMP (cGMP) response is common in patients presenting with acute heart failure (HF). Type V phosphodiesterase (PDEV) is known to be upregulated in HF and may explain the dysfunction of renal response. The aim of this study was to determine whether B-type natriuretic peptide (BNP) alone or in combination with PDEV inhibition improves renal function and increases urinary sodium and cGMP excretion in acute HF.

METHODS

This open-label study included 67 patients hospitalized with acute HF and renal dysfunction. Patients were randomized to standard care, low-dose intravenous BNP (0.005 µg/kg per minute), or combination BNP/PDEV inhibition with sildenafil (25 mg q12 hours) for 48 hours. The coprimary end points were the percent change in estimated glomerular filtration rate and blood urea nitrogen from baseline to 48 hours.

RESULTS

Treatment with BNP and BNP/PDEV inhibitor significantly increased plasma cGMP at 24 hours (+25.6% [+9.8%, +84.7%] and +60.8% [+32.3%, +103.8%] for BNP and BNP/PDEV versus -13.5% [-29.1%, +14.2%] with standard care; P=0.001). However, there was no significant change in estimated glomerular filtration rate 0 (-10.8%, +12.7%) for standard care versus 0 (-15.3%, +11.8%) for the BNP group versus -8.8% (-14.3%, +8.3%) for the BNP/PDEV group (P=0.60) or blood urea nitrogen -1.4% (-10.7%, +12.0%) for standard care versus -5.9% (-14.6%, +9.4%) for the BNP group versus +6.9% (-5.3%, +18.8%) for the BNP/PDEV group (P=0.38) between groups. Hypotension was more common in the BNP/PDEV inhibitor group.

CONCLUSIONS

BNP and combination BNP/PDEV inhibition increased plasma cGMP in patients with acute HF but did not improve renal function or urinary sodium/cGMP excretion. Our study does not support the use of intravenous low-dose BNP with or without PDEV inhibition to enhance renal function in patients admitted with acute HF.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT00972569.

Positive association between sodium-to-chloride ratio and in-hospital mortality of acute heart failure

Previous studies have suggested that levels of sodium and chloride in the blood may be indicative of the prognosis of different medical conditions. Nevertheless, the assessment of the prognostic significance of the sodium-to-chloride (Na/Cl) ratio in relation to in-hospital mortality among individuals suffering from acute heart failure (AHF) remains unexplored. In this study, the participants were selected from the Medical Information Mart for Intensive Care IV database and divided into three groups based on the Na/Cl ratio level upon admission. The primary results were the mortality rate within the hospital. Cox regression, Kaplan-Meier curves, receiver operator characteristic (ROC) curve analysis and subgroup analyses were utilized to investigate the correlation between the admission Na/Cl ratio and outcomes in critically ill patients with AHF. A total of 7844 patients who met the selection criteria were included in this study. After adjusting for confounders, the multivariable Cox regression analysis revealed that the baseline Na/Cl ratio significantly elevated the risk of in-hospital mortality among critically ill patients with AHF (HR = 1.34, 95% CI 1.21-1.49). Furthermore, when the Na/Cl ratio was converted into a categorical factor and the initial tertile was taken as a point of comparison, the hazard ratios (HRs) and 95% confidence intervals (CIs) for the second and third tertiles were 1.27 (1.05-1.54) and 1.53 (1.27-1.84), respectively. Additionally, a P value indicating a significant trend of < 0.001 was observed. ROC curve analysis showed that Na/Cl ratio had a more sensitive prognostic value in predicting in-hospital mortality of AHF than the sodium or chloride level alone (0.564 vs. 0.505, 0.544). Subgroup examinations indicated that the association between the Na/Cl ratio upon admission and the mortality rate of critically ill patients with AHF remained consistent in the subgroups of hyponatremia and hypochlorhydria (P for interaction > 0.05). The linear relationship between the Na/Cl ratio and in-hospital mortality in AHF patients indicates a positive association.

Updates in Cardiorenal Syndrome

Cardiorenal syndrome is a term that refers to a collection of disorders involving both the heart and kidneys, encompassing multi-directional pathways between the 2 organs mediated through low arterial perfusion, venous congestion, and neurohormonal activation. The pathophysiology is complex and includes hemodynamic and neurohormonal changes, but inconsistent findings from recent studies suggest this is very heterogenous disorder. Management for ADHF remains focused on decongestion and neurohormonal blockade to overcome the intense sodium and fluid avidity of the CRS.

The First Dedicated Comprehensive Heart Failure Program in the United States: The Division of Circulatory Physiology at Columbia Presbyterian (1992-2004)

The first dedicated multidisciplinary heart failure program in the United States was founded as the Division of Circulatory Physiology at the Columbia University College of Physicians & Surgeons in 1992. The Division was administratively and financially independent of the Division of Cardiology and grew to 24 faculty members at its peak. Its administrative innovations included (1) a comprehensive full-integrated service line, with 2 differentiated clinical teams, one devoted to drug therapy and the other to heart transplantation and ventricular assist devices; (2) a nurse specialist/physician assistant-led clinical service; and (3) a financial structure independent of (and not supported by) other cardiovascular medical or surgical services. The division had 3 overarching missions: (1) to promote a unique career development path for each faculty member to be linked to recognition in a specific area of heart failure expertise; (2) to change the trajectory and enhance the richness of intellectual discourse in the discipline of heart failure, so as to foster an understanding of fundamental mechanisms and to develop new therapeutics; and (3) to provide optimal medical care to patients and to promote the ability of other physicians to provide optimal care. The major research achievements of the division included (1) the development of beta-blockers for heart failure, from initial hemodynamic assessments to proof-of-concept studies to large-scale international trials; (2) the development and definitive assessment of flosequinan, amlodipine, and endothelin antagonists; (3) initial clinical trials and concerns with nesiritide; (4) large-scale trials evaluating dosing of angiotensin converting-enzyme inhibitors and the efficacy and safety of neprilysin inhibition; (5) identification of key mechanisms in heart failure, including neurohormonal activation, microcirculatory endothelial dysfunction, deficiencies in peripheral vasodilator pathways, noncardiac factors in driving dyspnea, and the first identification of subphenotypes of heart failure and a preserved ejection fraction; (6) the development of a volumetric approach to the assessment of myocardial shortening; (7) conceptualization and early studies of cardiac contractility modulation as a treatment for heart failure; (8) novel approaches to the identification of cardiac allograft rejection and new therapeutics to prevent allograft vasculopathy; and (9) demonstration of the effect of left ventricular assist devices to induce reverse remodeling, and the first randomized trial showing a survival benefit with ventricular assist devices. Above all, the division served as an exceptional incubator for a generation of leaders in the field of heart failure.

Impact of Prenatal Alcohol Exposure on the Development and Myocardium of Adult Mice: Morphometric Changes, Transcriptional Modulation of Genes Related to Cardiac Dysfunction, and Antioxidant Cardioprotection

The impact of prenatal alcohol exposure (PAE) varies considerably between individuals, leading to morphological and genetic changes. However, minor changes usually go undetected in PAE children. We investigated PAE's effects on gene transcription of genes related to cardiac dysfunction signaling in mouse myocardium and morphological changes. C57Bl/6 mice were subjected to a 10% PAE protocol. In postnatal days 2 and 60 (PN2 and PN60), morphometric measurements in the offspring were performed. Ventricular samples of the heart were collected in PN60 from male offspring for quantification of mRNA expression of 47 genes of nine myocardial signal transduction pathways related to cardiovascular dysfunction. Animals from the PAE group presented low birth weight than the Control group, but the differences were abolished in adult mice. In contrast, the mice's size was similar in PN2; however, PAE mice were oversized at PN60 compared with the Control group. Cardiac and ventricular indexes were increased in PAE mice. PAE modulated the mRNA expression of 43 genes, especially increasing the expressions of genes essential for maladaptive tissue remodeling. PAE animals presented increased antioxidant enzyme activities in the myocardium. In summary, PAE animals presented morphometric changes, transcription of cardiac dysfunction-related genes, and increased antioxidant protection in the myocardium.

Cardiac biomarkers and mortality in COVID-19 infection: A review

Lots of meta-analysis emphasize that a great number of hospitalized patients with moderate and severe forms of COVID-19 developed acute myocardial damage, defined as an increase of cardiac biomarkers, such N-terminal pro-B-type natriuretic peptide (NT-pro-BNP), creatine kinase-myocardial band (CK-MB) and of all type of troponins. The highest mortality rate is related with progressively increasing biomarkers levels and with a history of cardiovascular disease. In fact, the biomarkers dosage should be considered as a prognostic marker in all patients with COVID-19 disease at admission, during hospitalization and in the case of clinical deterioration. The purpose of this review is to evaluate cardiovascular prognostic factors in COVID-19 disease throughout the analysis of cardiac biomarkers to early identify the most serious patients and to optimize their outcomes.

Congestion in Patients with Advanced Heart Failure: Assessment and Treatment

Heart failure (HF) is characterized by frequent hospital admissions due to acute decompensation and shortened life span with a progressive clinical course leading to an advanced stage where traditional therapies become ineffective. Due to aging of the population and improved therapies, only a small of proportion of patients with advanced HF are candidates for surgical treatments, such as mechanical circulatory support or heart transplantation. In most cases, prompt identification and management of congestion is paramount to improving symptoms and quality of life and avoiding progression to severe multiorgan dysfunction and death.

Atrial Natriuretic Peptide31-67: A Novel Therapeutic Factor for Cardiovascular Diseases

The characterization of the cardiac hormone atrial natriuretic peptide (ANP_99–126), synthesized and secreted predominantly by atrial myocytes under stimulation by mechanical stretch, has established the heart as an endocrine organ with potent natriuretic, diuretic, and vasodilating actions. Three additional distinct polypeptides resulting from proteolytic cleavage of proANP have been identified in the circulation in humans. The mid-sequence proANP fragment 31–67 (also known as proANP_31–67) has unique potent and prolonged diuretic and natriuretic properties. In this review, we report the main effects of this circulating hormone in different tissues and organs, and its mechanisms of actions. We further highlight recent evidence on the cardiorenal protective actions of chronic supplementation of synthetic proANP_31–67 in preclinical models of cardiorenal disease. Finally, we evaluate the use of proANP_31–67 as a new therapeutic strategy to repair end-organ damage secondary to hypertension, diabetes mellitus, renal diseases, obesity, heart failure, and other morbidities that can lead to impaired cardiac function and structure.

Heart failure risk estimation based on novel biomarkers

Introduction: Despite advances in medical care, heart failure (HF)-associated morbidity and mortality remains high. Consequently, there is increased effort to find better ways for predicting, screening, and prognosticating HF in order to facilitate effective primary and secondary prevention.Areas covered: In this review, we describe the various biomarkers associated with different etiologic pathways implicated in HF, and discuss their roles in screening, diagnosing, prognosticating and predicting HF. We explore the emerging role of multi-omic approaches. We performed electronic searches in databases (PubMed and Google Scholar) through December 2020, using the following key terms: biomarker, novel, heart failure, risk, prediction, and estimation.Circulating BNP and troponin concentrations have been established in clinical care as key biomarkers for diagnosing and prognosticating HF. Emerging biomarkers (such as galectin-3 and ST-2) have gained further recognition for use in evaluating prognosis of HF patients. Promising biomarkers that are yet to be part of clinical recommendations include biomarkers of cardiorenal disease.Expert opinion: Increasing recognition of the complex and interdependent nature of pathophysiological pathways of HF has led to the application of multi-marker approaches including multi-omic high throughput assays. These newer approaches have the potential for new therapeutic discoveries and improving precision medicine in HF.

Targeting Cyclic Guanosine Monophosphate to Treat Heart Failure: JACC Review Topic of the Week

The significant morbidity and mortality associated with heart failure with reduced ejection fraction (HFrEF) or heart failure with preserved ejection fraction (HFpEF) justify the search for novel therapeutic agents. Reduced cyclic guanosine monophosphate levels contribute to HF progression. Among molecules modulating the nitric oxide (NO)-GMP-phosphodiesterase (PDE) pathway, the evaluation of nitrates, synthetic natriuretic peptides (NP), and NP analogs has yielded mixed results. Conversely, sacubitril/valsartan, combining NP degradation inhibition through neprilysin and angiotensin receptor blockade, has led to groundbreaking findings in HFrEF. Other strategies to increase tissue cyclic guanosine monophosphate have been attempted, such as PDE-3 or PDE-5 inhibition (with negative or neutral results), NO-independent soluble guanylate cyclase (sGC) activation, or enhancement of sGC sensitivity to endogenous NO. Following the positive results of the phase 3 VICTORIA (A Study of Vericiguat in Participants With Heart Failure With Reduced Ejection Fraction) trial on the sGC stimulator vericiguat in HFrEF, the main open questions are the efficacy of the sacubitril/valsartan-vericiguat combination in HFrEF and of vericiguat in HFpEF.

The Role of Neprilysin Inhibitors in the Treatment of Heart Failure with Preserved Ejection Fraction

Clinical and hemodynamic aggravation of heart failure with preserved ejection fraction (HFpEF) is largely due to progression of left ventricular (LV) diastolic dysfunction. The key role in the normal maintenance of diastolic function is played by a high level of activity of the intracellular signaling axis, cyclic guanosine-monophosphate-protein kinase G, the activity of which is significantly reduced in HFpEF. The activity of this axis can be increased by increasing the bioavailability of natriuretic peptides by blocking the enzyme neutral endopeptidase (neprilisin), which is responsible for the destruction of natriuretic peptides.This review presents experimental and clinical data on the use of neprilysin inhibitors in HFpEF and addresses prospects of this treatment.

B-type natriuretic peptide and cardiac remodelling after myocardial infarction: a randomised trial

OBJECTIVE

B-type natriuretic peptide (BNP) has favourable effects on left ventricular remodelling, including antifibrotic and antiapoptotic properties. We tested the hypothesis that infusion of BNP after an acute myocardial infarction would reduce left ventricular systolic and diastolic volumes and improve left ventricular ejection fraction compared with placebo.

METHODS

A total of 58 patients who underwent successful revascularisation for an acute ST elevation anterior myocardial infarction were randomised to receive 72-hour infusion of BNP at 0.006 µg/kg/min or placebo. Left ventricular end diastolic and systolic volumes and left ventricular ejection fraction were measured at baseline and at 30 days by multigated acquisition scan. Left ventricular infarction size was measured by cardiac MRI.

RESULTS

BNP infusion led to significantly higher BNP levels and plasma cyclic guanosine monophosphate at 72 hours. No significant difference in change of left ventricular volumes or ejection fraction from baseline to 30 days was observed between groups. Although left ventricular infarction size measured by cardiac MRI was not significantly different between BNP infusion versus placebo (p=0.39), there was a trend towards reduced infarction size in patients with a baseline ejection fraction of <40% (p=0.14).

CONCLUSIONS

Infusion of BNP in patients with an anterior myocardial infarction did not affect parameters of left ventricular remodelling. Patients treated with BNP who had a baseline left ventricular ejection fraction of <40% had a trend towards reduced left ventricular infarction size compared with placebo. These results do not support the use of intravenous BNP in patients after recent myocardial infarction.

TRIAL REGISTRATION NUMBER

NCT00573144.

BNP as a Major Player in the Heart-Kidney Connection

Brain natriuretic peptide (BNP) is an important biomarker for patients with heart failure, hypertension and cardiac hypertrophy. Although it is known that BNP levels are relatively higher in patients with chronic kidney disease and no heart disease, the mechanism remains unknown. Here, we review the functions and the roles of BNP in the heart-kidney interaction. In addition, we discuss the relevant molecular mechanisms that suggest BNP is protective against chronic kidney diseases and heart failure, especially in terms of the counterparts of the renin-angiotensin-aldosterone system (RAAS). The renal medulla has been reported to express depressor substances. The extract of the papillary tips from kidneys may induce the expression and secretion of BNP from cardiomyocytes. A better understanding of these processes will help accelerate pharmacological treatments for heart-kidney disease.

Role of Neprilysin Inhibitors in Heart Failure

Heart failure (HF) is a complex multifactorial medical condition that should be addressed according to its complexity and diversity. Currently, there is a medical arsenal available for the management of HF, but despite the advance in medical resources, its prevalence and social and financial impacts are still worrisome for the medical community and society. Among the numerous therapeutic options for the treatment of HF, neprilysin inhibitors have changed the perspective of the approach to titrate patients who suffer from this condition because neprilysin plays a role in the degradation of natriuretic peptides and various other vasoactive compounds that are crucial to counteract the devastating pathophysiology of HF. The purpose of this review was to analyze the role of neprilysin inhibitors in HF, focusing on newer therapy such as LCZ696 and studies that sustain its potential benefits in this medical entity.

Pharmacogenomics of the Natriuretic Peptide System in Heart Failure

PURPOSE OF REVIEW

Heart failure (HF) continues to be a public health burden despite advances in therapy, and the natriuretic peptide (NP) system is clearly of critical importance in this setting, spawning valuable diagnostic and prognostic testing, such as B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP), as well as current and future therapeutics, including recombinant natriuretic peptides (e.g., carperitide, nesiritide) and recently sacubitril, which inhibits the key clearance mechanism for NPs. This article intends to summarize the existing evidence for the role of NP system genetic variation on cardiovascular phenotypes relevant to HF with particular focus on the potential impact on pharmacologic therapies.

RECENT FINDINGS

Several genes in NP system have been interrogated, in many cases genetic variation impacting protein quantity and function or related disease states. Recent data supports genetic variants potentially impacting pharmacokinetics or dynamics of medications targeting the pathway. Growing evidence indicates the importance of genetic variation to the functioning of the NP system and its pharmacologic manipulation.

Evolving Role of Natriuretic Peptides from Diagnostic Tool to Therapeutic Modality

Natriuretic peptides (NP) are widely recognized as key regulators of blood pressure, water and salt homeostasis. In addition, they play a critical role in physiological cardiac growth and mediate a variety of biological effects including antiproliferative and anti-inflammatory effects in other organs and tissues. The cardiac release of NPs ANP and BNP represents an important compensatory mechanism during acute and chronic cardiac overload and during the pathogenesis of heart failure where their actions counteract the sustained activation of renin-angiotensin-aldosterone and other neurohormonal systems. Elevated circulating plasma NP levels correlate with the severity of heart failure and particularly BNP and the pro-peptide, NT-proBNP have been established as biomarkers for the diagnosis of heart failure as well as prognostic markers for cardiovascular risk. Despite activation of the NP system in heart failure it is inadequate to prevent progressive fluid and sodium retention and cardiac remodeling. Therapeutic approaches included administration of synthetic peptide analogs and the inhibition of NP-degrading enzyme neutral endopeptidase (NEP). Of all strategies only the combined NEP/ARB inhibition with sacubitril/valsartan had shown clinical success in reducing cardiovascular mortality and morbidity in patients with heart failure.

Comparative mRNA and MicroRNA Profiling during Acute Myocardial Infarction Induced by Coronary Occlusion and Ablation Radio-Frequency Currents

The ligation of the left anterior descending coronary artery is the most commonly used experimental model to induce myocardial infarction (MI) in rodents. A high mortality in the acute phase and the heterogeneity of the size of the MI obtained are drawbacks recognized in this model. In an attempt to solve the problem, our group recently developed a new MI experimental model which is based on application of myocardial ablation radio-frequency currents (AB-RF) that yielded MI with homogeneous sizes and significantly reduce acute mortality. In addition, cardiac structural, and functional changes aroused by AB-RF were similar to those seen in animals with MI induced by coronary artery ligation. Herein, we compared mRNA expression of genes that govern post-MI milieu in occlusion and ablation models. We analyzed 48 mRNAs expressions of nine different signal transduction pathways (cell survival and metabolism signs, matrix extracellular, cell cycle, oxidative stress, apoptosis, calcium signaling, hypertrophy markers, angiogenesis, and inflammation) in rat left ventricle 1 week after MI generated by both coronary occlusion and AB-RF. Furthermore, high-throughput miRNA analysis was also assessed in both MI procedures. Interestingly, mRNA expression levels and miRNA expressions showed strong similarities between both models after MI, with few specificities in each model, activating similar signal transduction pathways. To our knowledge, this is the first comparison of genomic alterations of mRNA and miRNA contents after two different MI procedures and identifies key signaling regulators modulating the pathophysiology of these two models that might culminate in heart failure. Furthermore, these analyses may contribute with the current knowledge concerning transcriptional and post-transcriptional changes of AB-RF protocol, arising as an alternative and effective MI method that reproduces most changes seem in coronary occlusion.

A perspective on sympathetic renal denervation in chronic congestive heart failure

Medical therapy has indisputably been the mainstay of management for chronic congestive heart failure. However, a significant percentage of patients continue to experience worsening heart failure (HF) symptoms despite treatment with multiple therapeutic agents. Recently, catheter-based interventional strategies that interrupt the renal sympathetic nervous system have shown promising results in providing better symptom control in patients with HF. In this article, we will review the pathophysiology of HF for better understanding of the interplay between the cardiovascular system and the kidney. Subsequently, we will briefly discuss pivotal renal denervation (RDN) therapy trials in patients with resistant hypertension and then present the available evidence on the role of RDN in HF therapy.

Perioperative Effects and Safety of Nesiritide Following Cardiac Surgery in Children

Nesiritide (Natrecor, Scios Inc), human B-type natriuretic peptide, has hemodynamic effects that may be beneficial in pediatric patients after cardiac surgery. Experience with nesiritide and pediatrics is limited. The purpose of this study was to evaluate perioperative effects and safety of nesiritide in pediatric cardiothoracic surgery. Seventeen patients with congenital heart disease undergoing cardiac surgery were given a loading dose (1 µg/kg) while on cardiopulmonary bypass (constant flow) followed by continuous infusion for 24 hours (0.01 µg/kg/min × 6 hours, then 0.02 µg/kg/min × 18 hours). A 7% decrease in mean blood pressure was seen following nesiritide loading dose on cardiopulmonary bypass. No patient required intervention for hypotension while receiving nesiritide load or infusion. Nesiritide load during surgery and continuous infusion after cardiac surgery in pediatric patients resulted in no significant hemodynamic compromise.

Effect of Nesiritide on Length of Hospital Stay in Patients with Decompensated Heart Failure

We examined the effect of nesiritide, administered as initial therapy, on length of hospital stay (LOS) and renal function through a retrospective analysis of 129 consecutive admissions to the coronary care unit in 98 patients diagnosed with congestive heart failure. Nesiritide was infused during 58 admissions (nesiritide group) while other therapies, not including nesiritide, were used during 71 admissions (non-nesiritide group). Although the nesiritide group showed lower baseline left ventricular ejection fraction and systolic blood pressure, higher serum creatinine, and a longer QRS interval, the LOS of this group was significantly shorter compared to the non-nesiritide group (3.91 ± 1.3 vs 4.77 ± 1.7 days, P = .0023). Both groups were similar with respect to body weight change (negative fluid balance), a slight decrease in blood urea nitrogen, and unchanged serum creatinine. Nesiritide as an initial therapy for treatment of congestive heart failure results in a more rapid hospital discharge without compromising renal function.

The Mechanism of Action of LCZ696

Heart failure (HF) represents a growing financial burden on healthcare systems and despite therapeutic advances, mortality remains high. Current treatments focus on blocking neurohormonal pathways, such as the renin-angiotensin aldosterone system (RAAS). Recent research has focused on the natriuretic peptide system, which confers beneficial effects in HF, whereas activation of the RAAS and of the sympathetic nervous system has detrimental effects. LCZ696 (sacubutril/valsartan), a first-in-class angiotensin II AT[1] receptor neprilysin inhibitor, has a unique mode of action that targets both pathways. Clinical studies to date indicate that LCZ696 is effective and safe in mild to moderate arterial hypertension and in HF patients with preserved ejection fraction, and has been shown to be superior to enalapril in patients with moderate to severe HF due to reduced left ventricular ejection fraction.

Relationship of N-Terminal fragment of Pro-B-Type Natriuretic Peptide and copeptin with erythrocytes-related parameters: A population-based study

BACKGROUND

Plasma levels of natriuretic peptides (NP) have been inversely related to hemoglobin (Hb) concentration in prior studies. However, the mechanism underlying this association remains unclear. We aimed to obtain further insights into potential mechanisms for this correlation in a cohort of healthy adults.

METHODS

A population-based study was performed among 2113 healthy adults aged 25-41years. Relationships of N-Terminal fragment of Pro-B-Type Natriuretic Peptide (NT-proBNP) or copeptin with volume-dependent (Hb, hematocrit (Hct), erythrocyte count (EC), mean corpuscular Hb concentration (MCHC)) and volume-independent (mean corpuscular volume (MCV), mean corpuscular Hb (MCH)) erythrocyte-related parameters were assessed using sex-specific multivariable linear regression analyses.

RESULTS

The median age was 36.7years. Median NT-proBNP (ng/L) levels were 49.5 and 20 among women and men, respectively (p<0.0001). Mean (standard deviation) Hb (g/L) levels were 130.1(9.1) and 149.7(8.6) among women and men, respectively (p<0.0001). Among men, multivariable adjusted β-coefficients (95% confidence interval) for NT-proBNP were -1.68 (-2.36; -1.01), p<0.0001 for Hb; -0.38 (-0.57; -0.20), p<0.0001 for Hct; -0.06 (-0.09; -0.04), p<0.0001 for EC; -0.78 (-1.50; -0.07), p=0.03 for MCHC; 0.26 (-0.04; 0.56), p=0.09 for MCV; and 0.03 (-0.08; 0.14), p=0.61 for MCH. For copeptin, these relationships were 1.36 (0.39; 2.32), p=0.006; 0.41 (0.15; 0.68), p=0.002; 0.06 (0.02; 0.09), p=0.002; -0.17 (-1.19; 0.86), p=0.75; -0.12 (-0.55; 0.31), p=0.58 and -0.05 (-0.21; 0.10), p=0.52. Similar results were observed among women.

CONCLUSIONS

We found significant relationships of NT-proBNP and copeptin with volume-dependent but not volume-independent erythrocyte-related parameters, suggesting that hemodilution may at least in part explain these associations.

Clinical Characteristics and Treatment of Cardiomyopathies in Children

Cardiomyopathies are diseases of the heart muscle, a term introduced in 1957 to identify a group of myocardial diseases not attributable to coronary artery disease. The definition has since been modified to refer to structural and or functional abnormalities of the myocardium where other known causes of myocardial dysfunction, such as systemic hypertension, valvular disease and ischemic heart disease, have been excluded. In this review, we discuss the pathophysiology, clinical assessment and therapeutic strategies for hypertrophic, dilated and hypertrophic cardiomyopathies, with a particular focus on aspects unique to children.

Effect of natriuretic peptides on cerebral artery blood flow in healthy volunteers

The natriuretic peptides (NPs), atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP), have vasoactive functions that concern humans and most animals, but their specific effects on cerebral circulation are poorly understood. We therefore examined the responsiveness of cerebral arteries to different doses of the natriuretic peptides in animals and humans. We conducted a dose-response experiment in guinea pigs (in vitro) and a double-blind, three-way cross-over study in healthy volunteers (in vivo). In the animal experiment, we administered cumulative doses of NPs to pre-contracted segments of cerebral arteries. In the main study, six healthy volunteers were randomly allocated to receive two intravenous doses of ANP, BNP or CNP, respectively, over 20 min on three separate study days. We recorded blood flow velocity in the middle cerebral artery (VMCA) by transcranial Doppler. In addition, we measured temporal and radial artery diameters, headache response and plasma concentrations of the NPs. In guinea pigs, ANP and BNP but not CNP showed significant dose-dependent relaxation of cerebral arteries. In healthy humans, NP infusion had no effect on mean VMCA, and we found no difference in hemodynamic responses between the NPs. Furthermore, natriuretic peptides did not affect temporal and radial artery diameters or induce headache. In conclusion, natriuretic peptides in physiological and pharmacological doses do not affect blood flow velocity in the middle cerebral artery or dilate extracerebral arteries in healthy volunteers.

Natriuretic Peptides and Cardiometabolic Health

Natriuretic peptides are cardiac-derived hormones with a range of protective functions, including natriuresis, diuresis, vasodilation, lusitropy, lipolysis, weight loss, and improved insulin sensitivity. Their actions are mediated through membrane-bound guanylyl cyclases that lead to production of the intracellular second-messenger cyclic guanosine monophosphate. A growing body of evidence demonstrates that genetic and acquired deficiencies of the natriuretic peptide system can promote hypertension, cardiac hypertrophy, obesity, diabetes mellitus, the metabolic syndrome, and heart failure. Clinically, natriuretic peptides are robust diagnostic and prognostic markers, and augmenting natriuretic peptides is a target for therapeutic strategies in cardiometabolic disease. This review will summarize current understanding and highlight novel aspects of natriuretic peptide biology.

Pathogenesis and treatment of the cardiorenal syndrome: Implications of L-arginine-nitric oxide pathway impairment

A highly complex interplay exists between the heart and kidney in the setting of both normal and abnormal physiology. In the context of heart failure, a pathophysiological condition termed the cardiorenal syndrome (CRS) exists whereby dysfunction in the heart or kidney can accelerate pathology in the other organ. The mechanisms that underpin CRS are complex, and include neuro-hormonal activation, oxidative stress and endothelial dysfunction. The endothelium plays a central role in the regulation of both cardiac and renal function, and as such impairments in endothelial function can lead to dysfunction of both these organs. In particular, reduced bioavailability of nitric oxide (NO) is a key pathophysiologic component of endothelial dysfunction. The synthesis of NO by the endothelium is critically dependent on the plasmalemmal transport of its substrate, L-arginine, via the cationic amino acid transporter-1 (CAT1). Impaired L-arginine-NO pathway activity has been demonstrated individually in heart and renal failure. Recent findings suggest abnormalities of the L-arginine-NO pathway also play a role in the pathogenesis of CRS and thus this pathway may represent a potential new target for the treatment of heart and renal failure.

Increased yield of high purity recombinant human brain natriuretic peptide by acid hydrolysis of short fusion partner in Escherichia coli

Recombinant human B-type natriuretic peptide (rhBNP) is a 32-amino acid peptide used to treat congestive heart failure. In this paper, we report a method for the increased production of rhBNP in Escherichia coli with high purity. hBNP was cloned with a short growth hormone fusion partner coupled with a unique acid-labile dipeptide linker to cleave the fusion protein to release the rhBNP. The recombinant fusion protein was expressed as an inclusion body (IB) and the fermentation process was optimized to produce on large scale. The IBs were recovered by cell lysis, and the pure IBs were directly treated with diluted acid to get the target peptide from the fusion protein and the resultant peptide was purified by reversed phase chromatography. The final purity of the rhBNP was more than 99% with yield of 50mg per liter of culture, which is ten times higher than the previous reports. The purified rhBNP exhibited specific biological activity similar to the standard peptide in producing cyclic-guanosine monophosphate.

Genetic and nongenetic factors influencing pharmacokinetics of B-type natriuretic peptide

BACKGROUND

Natriuretic peptides (NPs) represent a critical pathway in heart failure (HF). However, there is wide individual variability in NP system activity, which could be partly genetic in origin. We explored genetic and nongenetic contributions to B-type natriuretic peptide (BNP) inactivation.

METHODS

Chronic HF patients (n = 95) received recombinant human BNP (nesiritide) at standard doses, and BNP levels were measured at baseline, after 2 hours of infusion, and 30 minutes after discontinuation. Genomic DNA was genotyped for 91 single-nucleotide polymorphisms (SNP) in 2 candidate genes. We tested the association of patient characteristics and genotype with 5 pharmacokinetics (PK) parameters: elimination rate constant, ΔBNP, BNP clearance, adjusted BNP clearance, and half-life. Linear regression with pleiotropic analysis was used to test genotype associations with PK.

RESULTS

Participants' mean age was 63 years, 44% were female, and 46% were African American. PK parameters varied widely, some >10-fold. HF type (preserved vs reduced) was associated with PK (P < .01), whereas renal function, demographics, and body mass index and were not. Two SNPs in MME (rs989692, rs6798179) and 2 in NPR3 (rs6880564, rs2062708) also had associations with PK (P < .05).

CONCLUSIONS

The pharmacokinetics of BNP varies greatly in HF patients, differs by HF type, and possibly by MME or NPR3 genotype. Additional study is warranted.

Diagnosing heart failure with preserved ejection fraction

INTRODUCTION

Heart failure with preserved ejection fraction (HFPEF) is a common syndrome, accounting for about 50% of all patients with heart failure (HF). Morbidity and mortality are similar to patients with HF with reduced ejection fraction (HFREF), yet no effective treatment has been identified in randomized clinical trials.

AREAS COVERED

This article provides an overview of the available literature regarding diagnosing established HFPEF and potential new therapeutic targets for the early diagnosis of HFPEF. Vascular dysfunction, ventricular-arterial coupling, oxidative stress, extracellular matrix regulation, chronotropic incompetence, pulmonary hypertension, exercise testing and biomarkers were taken into consideration next to conventional measurements of diastolic dysfunction.

EXPERT OPINION

Measuring diastolic dysfunction in HFPEF is considered important in many patients. Nevertheless, today we know that other causes besides diastolic dysfunction are also involved in the pathophysiology of many HFPEF patients and need to be investigated in order to make a correct diagnosis. Therefore, further research is required to allow better and more specific diagnostic and treatment options to reduce the morbidity and mortality for this ever-expanding HF population.

Effects of nesiritide and predictors of urine output in acute decompensated heart failure: results from ASCEND-HF (acute study of clinical effectiveness of nesiritide and decompensated heart failure)

OBJECTIVES

This study sought to determine if nesiritide increases diuresis in congestive heart failure patients.

BACKGROUND

In the ASCEND-HF (Acute Study of Clinical Effectiveness of Nesiritide and Decompensated Heart Failure), 7,141 patients hospitalized with acute decompensated heart failure (ADHF) were randomized to receive nesiritide or placebo for 24 to 168 h, in addition to standard care. There were minimal effects of nesiritide on survival, future hospitalizations, and symptoms. However, whether or not nesiritide increases diuresis in ADHF patients is unknown.

METHODS

Urine output was measured in 5,864 subjects; of these, 5,320 received loop diuretics and had dose data recorded. Loop diuretics other than furosemide were converted to furosemide equivalent doses. A total of 4,881 patients had complete data. We used logistic regression models to identify the impact of nesiritide on urine output and the factors associated with high urine output.

RESULTS

Median (25th, 75th percentiles) 24-h urine output was 2,280 (1,550, 3,280) ml with nesiritide and 2,200 (1,550, 3,200) ml with placebo (p = NS). Loop diuretic dose (furosemide equivalent) was 80 (40, 140) mg with both nesiritide and placebo. Diuretic dose was a strong predictor of urine output. Other independent predictors included: male sex, greater body mass index, higher diastolic blood pressure, elevated jugular venous pressure, recent weight gain, and lower blood urea nitrogen. The addition of nesiritide did not change urine output. None of the interaction terms between nesiritide and predictors affected the urine output prediction.

CONCLUSIONS

Nesiritide did not increase urine output in patients with ADHF. Higher diuretic dose was a strong predictor of higher urine output, but neurohormonal activation (as evidenced by blood urea nitrogen concentration) and lower blood pressure limited diuresis.

Clinical utility of natriuretic peptides in left ventricular failure

Left ventricular failure (LVF) is a clinical syndrome caused by abnormal systolic or diastolic function failing to meet the metabolic requirements of the body. It is important to diagnose and manage LVF in the earliest stages to prevent mortality and morbidity. This article extensively reviews the diagnostic, therapeutic, and prognostic utility of natriuretic peptides in LVF.

Biomarkers and diagnostics in heart failure

Heart failure (HF) biomarkers have dramatically impacted the way HF patients are evaluated and managed. B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) are the gold standard biomarkers in determining the diagnosis and prognosis of HF, and studies on natriuretic peptide-guided HF management look promising. An array of additional biomarkers has emerged, each reflecting different pathophysiological processes in the development and progression of HF: myocardial insult, inflammation and remodeling. Novel biomarkers, such as mid-regional pro atrial natriuretic peptide (MR-proANP), mid-regional pro adrenomedullin (MR-proADM), highly sensitive troponins, soluble ST2 (sST2), growth differentiation factor (GDF)-15 and Galectin-3, show potential in determining prognosis beyond the established natriuretic peptides, but their role in the clinical care of the patient is still partially defined and more studies are needed. This article is part of a Special Issue entitled: Heart failure pathogenesis and emerging diagnostic and therapeutic interventions.

Current strategies for preventing renal dysfunction in patients with heart failure: a heart failure stage approach

Renal dysfunction is common during episodes of acute decompensated heart failure, and historical data indicate that the mean creatinine level at admission has risen in recent decades. Different mechanisms underlying this change over time have been proposed, such as demographic changes, hemodynamic and neurohumoral derangements and medical interventions. In this setting, various strategies have been proposed for the prevention of renal dysfunction with heterogeneous results. In the present article, we review and discuss the main aspects of renal dysfunction prevention according to the different stages of heart failure.

BNP molecular forms and processing by the cardiac serine protease corin

The cardiac hormone, B-type natriuretic peptide (BNP), is one of human natriuretic peptides which possesses cardiorenal protective actions and is used as a therapeutic and a biomarker for heart failure (HF). Its prohormone, proBNP1_108, is processed by the proNPs convertases, corin or furin, to inactive NT-proBNP1_76 and active BNP1-32. Paradoxically, circulating NT-proBNP and BNP are elevated in HF leading to the use of BNP as a sensitive and predictive marker of HF. This paradox may be explained by the "nonspecific" nature of conventional assays and/or a relative deficiency state of "active BNP" as characterized by an increase in inactive proBNP_108 and a decrease in active BNP1-32. Therefore, understanding the regulation of proBNP1_108 processing and the role of the convertase corin may be important in understanding the physiology of HF. Corin is expressed in heart and kidney and may play an important role in regulating blood pressure and remodeling of the heart. The processing of proBNP1_108 by corin may be controlled by O-linked glycosylation of proBNP1-108. A potential impairment of proBNP1lo8 processing in HF may be linked to dysregulation of the convertase corin, which may offer therapeutic opportunities to control proBNPlo0s processing and its activation in HF.

The ASCEND-HF trial: an acute study of clinical effectiveness of nesiritide and decompensated heart failure

Nesiritide has been approved by the US FDA for the treatment of acute decompensated heart failure since 2001. Subsequently, two meta-analyses questioned its impact on mortality and association with worsening renal function. Therefore, the Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure trial was designed to assess the safety and efficacy of nesiritide in acute decompensated heart failure based on clinically relevant outcomes. In this article, the important findings and lessons learned from this landmark study are reviewed and potential evolving roles for nesiritide and natriuretic peptides in the future of heart failure therapy are proposed.

Treating volume overload in acutely decompensated heart failure: established and novel therapeutic approaches

BACKGROUND

Most patients hospitalized for acutely decompensated heart failure (ADHF) present with symptoms and signs of volume overload, which is also associated with substantially high rates of death and rehospitalization in ADHF.

OBJECTIVE

To review the recent experimental and clinical evidence on existing therapeutic algorithms and investigational drugs used for the treatment of volume overload in ADHF patients.

METHODS

A systematic search of peer-reviewed publications was performed on Medline and EMBASE from January 1990 to March 2012. The results of unpublished trials were obtained from presentations at national and international meetings.

RESULTS

Apart from intrinsic renal insufficiency and neurohormonal activation, volume overload through venous congestion may be the primary haemodynamic factor triggering the worsening of renal function in ADHF patients. It is well known that heart and kidneys are closely interrelated and an acute or chronic disorder in one organ may induce acute or chronic dysfunction in the other organ. Established therapeutic strategies, (e.g. loop diuretics, vasodilators, and inotropes), are sometimes associated with limited clinical success due to tolerance and the need for frequent up titration of the doses in order to achieve the desired effect. That leads to an increasing interest in novel options, such as the use of adenosine A1 receptor antagonists, vasopressin antagonists, and renal-protective dopamine. Initial clinical trials have shown quite encouraging results in some heart failure subpopulations but have failed to demonstrate a clear beneficial role of these agents. On the other hand, ultrafiltration appears to be a more promising therapeutic procedure that will improve volume regulation, while preserving renal and cardiac function.

CONCLUSION

Further clinical studies are required in order to determine their net effect on renal function and potential cardiovascular outcomes. Until then, management of volume overload in ADHF patients remains a challenge for the clinicians.

The epidemiology and pathophysiology of heart failure

Heart failure (HF) remains a major growing public health problem in the United States. Despite extensive understanding of the mechanism at the molecular level and innovations in therapy, HF carries high morbidity and mortality rates, with frequent hospital admissions. In the Medicare population, HF is the leading cause for hospitalization, accounting for more than1 million admissions per year. The authors provide a review of the epidemiology and pathophysiology of HF.