Nesiritide for the treatment of decompensated heart failure

An insight into the pharmacology of cysteine/methionine containing peptide drugs

Since last century, peptides have emerged as potential drugs with >90 FDA approvals for various targets with several in the pipeline. Sulphur, in peptides is present either as thiol (-SH) from Cys or thioether from Met. In this review, all the peptides approved by FDA since 2000 containing sulphur have been included. Among them ∼50 % contains disulphide bridges. This clearly demonstrates the significance of disulphide bonds in peptide drugs. This can be achieved synthetically by using orthogonal protecting groups (PGs) for -SH. These PGs are compatible with Solid Phase Peptide Synthesis (SPPS), which is still the method of choice for peptide synthesis. The orthogonal PGs used for Cys thiol side chain protecting for disulphide bond formation have been included which are currently in use both by academia and industry from small scale to large scale synthesis. In addition, the details of the FDA approved drugs containing Cys and Met (or both) have also been discussed.

Uncovering hidden therapeutic indications through drug repurposing with graph neural networks and heterogeneous data

Drug repurposing has gained the attention of many in the recent years. The practice of repurposing existing drugs for new therapeutic uses helps to simplify the drug discovery process, which in turn reduces the costs and risks that are associated with de novo development. Representing biomedical data in the form of a graph is a simple and effective method to depict the underlying structure of the information. Using deep neural networks in combination with this data represents a promising approach to address drug repurposing. This paper presents BEHOR a more comprehensive version of the REDIRECTION model, which was previously presented. Both versions utilize the DISNET biomedical graph as the primary source of information, providing the model with extensive and intricate data to tackle the drug repurposing challenge. This new version's results for the reported metrics in the RepoDB test are 0.9604 for AUROC and 0.9518 for AUPRC. Additionally, a discussion is provided regarding some of the novel predictions to demonstrate the reliability of the model. The authors believe that BEHOR holds promise for generating drug repurposing hypotheses and could greatly benefit the field.

Snake Venom Components as Therapeutic Drugs in Ischemic Heart Disease

Ischemic heart disease (IHD), especially myocardial infarction (MI), is a leading cause of death worldwide. Although coronary reperfusion is the most straightforward treatment for limiting the MI size, it has nevertheless been shown to exacerbate ischemic myocardial injury. Therefore, identifying and developing therapeutic strategies to treat IHD is a major medical challenge. Snake venoms contain biologically active proteins and peptides that are of major interest for pharmacological applications in the cardiovascular system (CVS). This has led to their use for the development and design of new drugs, such as the first-in-class angiotensin-converting enzyme inhibitor captopril, developed from a peptide present in Bothrops jararaca snake venom. This review discusses the potential usefulness of snake venom toxins for developing effective treatments against IHD and related diseases such as hypertension and atherosclerosis. It describes their biological effects at the molecular scale, their mechanisms of action according to their different pharmacological properties, as well as their subsequent molecular pathways and therapeutic targets. The molecules reported here have either been approved for human medical use and are currently available on the drug market or are still in the clinical or preclinical developmental stages. The information summarized here may be useful in providing insights into the development of future snake venom-derived drugs.

NO mediates the effect of the synthetic natriuretic peptide NPCdc on kidney and aorta in nephrectomised rats

NPCdc is a synthetic natriuretic peptide that was originally derived from another peptide, the NP2_Casca, isolated from Crotalus durissus cascavella venom. These molecules share 70% structural homology with natriuretic peptides obtained from different species, including humans. NP2_Casca induces vasorelaxation and increases nitric oxide levels independently of natriuretic peptide receptors A and B. This study aimed to investigate whether NPCdc-induced hypotension in control rats and rats with a reduced kidney mass is associated with effects on the glomerular filtration rate, NADPH oxidase activity and components downstream of natriuretic peptide receptor C (NPR-C). Anaesthetized Wistar rats that were subjected to a sham operation and 5/6 nephrectomy (5/6Nx) were infused with saline (vehicle) or NPCdc (7.5 μg/kg/min) for 70 min. The NPCdc treatment decreased the mean arterial pressure and NADPH oxidase activity while simultaneously increasing the glomerular filtration rate, fractional Na⁺ excretion and nitric oxide level. After 70 min, the levels of p-AKT ^Ser-473, p-eNOS ^Ser-1177, p-nNOS ^Ser-1417 and p-iNOS^Tyr-151 were not affected. However, p-ERK1/2 ^{Thr-202/Tyr-204} levels were altered. Thus, nitric oxide and components of NPR-C signalling mediate the effects of NPCdc. The results suggest a potential therapeutic application of this peptide for cardiorenal syndrome.

Fluid Management: Pharmacologic and Renal Replacement Therapies

OBJECTIVES

Focusing on critically ill children with cardiac disease, we will review common causes of fluid perturbations, clinical recognition, and strategies to minimize and treat fluid-related complications.

DATA SOURCE

MEDLINE and PubMed.

CONCLUSIONS

Meticulous fluid management is vital in critically ill children with cardiac disease. Fluid therapy is important to maintain adequate blood volume and perfusion pressure in order to support cardiac output, tissue perfusion, and oxygen delivery. However, fluid overload and acute kidney injury are common and are associated with increased morbidity and mortality. Understanding the etiologies for disturbances in volume status and the pathophysiology surrounding those conditions is crucial for providing optimal care.

The dose-dependent effect of nesiritide on renal function in patients with acute decompensated heart failure: a systematic review and meta-analysis of randomized controlled trials

Background

Conflicting renal effects of nesiritide have been reported in patients with acute decompensated heart failure. To answer this controversy, we performed a meta-analysis of randomized controlled trials to evaluate the influence of nesiritide on renal function in patients with acute decompensated heart failure.

Methods

Articles were obtained from PubMed, Medline, Cochrane Library and reference review. Randomized controlled studies that investigated the effects of continuous infusion of nesiritide on renal function in adult patients with acute decompensated heart failure were included and analyzed. Fixed-effect model was used to estimate relative risk (RR) and weight mean difference (WMD). The quality assessment of each study, subgroup, sensitivity, and publication bias analyses were performed.

Results

Fifteen randomized controlled trials were eligible for inclusion. Most of included studies had relatively high quality and no publication bias was found. Overall, compared to control therapies, nesiritide might increase the risk of worsening renal function in patients with acute decompensated heart failure (RR 1.08, 95% CI 1.01–1.15, P = 0.023). In subgroup analysis, high-dose nesiritide strongly associated with renal dysfunction (RR 1.54, 95% CI 1.19-2.00, P = 0.001), but no statistical differences were observed in standard-dose (RR 1.04, 95% CI 0.98-1.12, P = 0.213), low-dose groups (RR 1.01, 95% CI 0.74-1.37, P = 0.968) and same results were identified in the subgroup analysis of placebo controlled trials. Peak mean change of serum creatinine from baseline was no significant difference (WMD -2.54, 95% CI -5.76-0.67, P = 0.121).

Conclusions

In our meta-analysis, nesiritide may have a dose-dependent effect on renal function in patients with acute decompensated heart failure. High-dose nesiritide is likely to increase the risk of worsening renal function, but standard-dose and low-dose nesiritide probably have no impact on renal function. These findings could be helpful to optimize the use of nesiritide in clinical practice.

Comparative effects of recombinant human brain natriuretic peptide and dobutamine on acute decompensated heart failure patients with different blood BNP levels

Background

Recombinant human B-type natriuretic peptide (rhBNP) has been indicated for the treatment of acute decompensated heart failure (ADHF). However, the therapeutic efficacy of intravenous rhBNP is not always satisfactory in patients with extremely high blood BNP levels. In this study, we evaluated the effects of rhBNP on patients with different BNP levels.

Methods

One hundred and five patients with ADHF whose left ventricular ejection fraction (LVEF) was <40%, were assigned to a high BNP group (BNP ≤ 3000 pg/mL) or an extra-high BNP group (BNP > 3000 pg/mL) , depending on their admission plasma BNP levels. Each group was then subdivided into rhBNP or dobutamine subgroups according to intravenous administration with either rhBNP or dobutamine for 24-72h. In the high BNP group, 58 patients were randomized to subgroup rhBNP (n = 28) and subgroup dobutamine (n = 30). In the extra-high BNP group, 47 patients were randomized to subgroup rhBNP (n = 24) and subgroup dobutamine (n = 23). The effects of rhBNP and dobutamine on patients in the high and extra-high BNP groups were compared.

Results

In the high BNP group, rhBNP was more efficient than dobutamine at improving NYHA classification (P < 0.05), decreasing plasma BNP levels (P < 0.05), increasing LVEF (P < 0.05), and reducing hospital length of stay (P < 0.05). However, rhBNP displayed no superior therapeutic efficacy to dobutamine in the extra-high BNP group. Adverse cardiovascular events in patients treated with rhBNP were similar to adverse events in patients treated with dobutamine in both the high and extra-high BNP groups.

Conclusions

rhBNP was more efficient than dobutamine at improving heart function in patients with ADHF when plasma BNP was ≤3000 pg/mL. However, rhBNP treatment showed no advantages over dobutamine when plasma BNP reached extremely high levels (>3000 pg/mL).

Trial registration

ClinicalTrials.gov Identifier: NCT01837849.

Cinaciguat, a soluble guanylate cyclase activator, unloads the heart but also causes hypotension in acute decompensated heart failure

AIMS

Cinaciguat (BAY 58-2667) is a novel soluble guanylate cyclase activator. This study evaluated the haemodynamic effect and safety of cinaciguat added to standard therapy in patients with acute decompensated heart failure (ADHF).

METHODS AND RESULTS

In this placebo-controlled, phase IIb study (NCT00559650), 139 patients admitted with ADHF, pulmonary capillary wedge pressure (PCWP) ≥18 mmHg, left ventricular ejection fraction <40%, and a pre-existing need for invasive haemodynamic monitoring were randomized 2:1 to cinaciguat:placebo (continuous i.v. infusion). The dose was titrated for 8 h and maintained for 16-40 h (starting dose: 100 μg/h). At 8 h, mean PCWP changed from 25.7 ± 5.0 mmHg by -7.7 mmHg with cinaciguat and from 25.0 ± 5.3 mmHg by -3.7 mmHg with placebo (P < 0.0001). The mean right atrial pressure changed from 12.4 ± 5.3 mmHg by -2.7 mmHg with cinaciguat and from 11.8 ± 4.9 mmHg by -0.6 mmHg with placebo (P= 0.0019). Cinaciguat also decreased the pulmonary and systemic vascular resistance and the mean arterial pressure, and increased the cardiac index (all P < 0.0001 vs. placebo). Systolic blood pressure changed by -21.6 ± 17.0 mmHg with cinaciguat and -5.0 ± 14.5 mmHg with placebo. Adverse events were experienced by 71 and 45% of patients receiving cinaciguat and placebo, respectively. No adverse effects on the 30-day mortality were seen; however, the trial was stopped prematurely due to an increased occurrence of hypotension at cinaciguat doses ≥200 µg/h.

CONCLUSION

Cinaciguat unloaded the heart in patients with ADHF. However, high doses were associated with hypotension.

Phosphodiesterases and cardiac cGMP: evolving roles and controversies

cGMP and its primary target kinase, protein kinase G (PKG), are well recognized modulators of cardiac function and the chronic stress response. Their enhancement appears to serve as a myocardial brake, reducing maladaptive hypertrophy, improving cell survival, signaling and mitochondrial function, protecting against ischemia/reperfusion injury, and blunting the stimulatory effects of catecholamines. Translation of these effects into a chronic treatment for patients with heart failure based on increasing the generation of cGMP has been difficult, however, with tolerance and hypotension effects occurring with nitrates and neutral responses to natriuretic peptides (at least B-type). Inhibition of cGMP-targeted phosphodiesterases (PDEs) such as PDE5A is an alternative approach that appears to have more potent effects. Recent studies in experimental models and patients are revealing benefits in heart failure syndromes, and ongoing multicenter trials are testing the efficacy of PDE5A inhibition. In this review we discuss recent research findings and controversies regarding the PDE/cGMP/PKG signaling pathway, and suggest directions for further research.

Cardiorenal syndrome and heart failure

PURPOSE OF REVIEW

Concomitant anemia, heart failure, and renal disease can be seen in a large proportion of patients with heart failure. The purpose of this review is to discuss the current definitions and mechanisms involved in this pathophysiological relationship, as well as the potential management and treatment options available for these patients.

RECENT FINDING

Dysfunctional heart can promote the dysfunction of the kidneys through a variety of pathophysiological mechanism, the reciprocal holds true as well. Heart failure has been considered as the most common type of cardiovascular complication seen in patients with renal failure. Central to this relationship lies anemia, which can be the result or the cause of either heart or kidney disease.

SUMMARY

Cardiorenal syndrome is a complex condition, which requires the collaboration and resources from cardiology, cardiac surgery, nephrology, and critical care. Of great importance is recognizing the presence of cardiorenal syndrome and appreciating the impact it can play on treatment options and survival.

Brain natriuretic peptide in pulmonary arterial hypertension: biomarker and potential therapeutic agent

B-type natriuretic peptide (BNP) is a member of the natriuretic peptide family, a group of widely distributed, but evolutionarily conserved, polypeptide mediators that exert myriad cardiovascular effects. BNP is a potent vasodilator with mitogenic, hypertrophic and pro-inflammatory properties that is upregulated in pulmonary hypertensive diseases. Circulating levels of BNP correlate with mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) in patients with pulmonary arterial hypertension (PAH). Elevated plasma BNP levels are associated with increased mortality in patients with PAH and a fall in BNP levels after therapy is associated with improved survival. These findings have important clinical implications in that a noninvasive blood test may be used to identify PAH patients at high-risk of decompensation and to guide pulmonary vasodilator therapy. BNP also has several biologic effects that could be beneficial to patients with PAH. However, lack of a convenient method for achieving sustained increases in circulating BNP levels has impeded the development of BNP as a therapy for treating pulmonary hypertension. New technologies that allow transdermal or oral administration of the natriuretic peptides have the potential to greatly accelerate research into therapeutic use of BNP for cor pulmonale and pulmonary vascular diseases. This review will examine the basic science and clinical research that has led to our understanding of the role of BNP in cardiovascular physiology, its use as a biomarker of right ventricular function and its therapeutic potential for managing patients with pulmonary vascular disease.

Rolofylline: a selective adenosine 1 receptor antagonist for the treatment of heart failure

BACKGROUND

Co-existent cardiac and renal dysfunction is increasingly recognized as both a predictor and mediator of poor outcomes in patients with advanced heart failure. Novel therapies, including adenosine receptor antagonists, are currently under development for the treatment of 'cardiorenal syndrome'.

OBJECTIVES

To review the pathophysiologic rationale for using rolofylline, a selective adenosine 1 receptor antagonist, in patients with cardiorenal syndrome; and to provide a critical overview of safety and efficacy data from clinical studies.

METHODS

We reviewed published data on the pharmacology of rolofylline, and used this to inform a comprehensive summary of preclinical and clinical trials. Cardiac and renal effects, and safety data with a particular reference to seizures, are highlighted.

RESULTS/CONCLUSION

Rolofylline facilitates diuresis and preserves renal function in patients with acute decompensated heart failure and renal dysfunction. Pilot data also suggest beneficial effects on symptoms and short-term outcomes. The risk of seizures may be minimized by excluding high-risk patients.

Hepatic and renal protection during cardiac surgery

Hepatic injury in cardiac surgery is a rare complication but is associated with significant morbidity and mortality. A high index of suspicion postoperatively will lead to earlier treatment directed at eliminating or minimizing ongoing hepatic injury while preventing additional metabolic stress from ischemia, hemorrhage, or sepsis. The evidence-basis for perioperative renal risk factors remains hampered by the inconsistent definitions for renal injury. Although acute kidney injury (as defined by the Risk, Injury, Failure, Loss, End-stage criteria) has become accepted, it does not address pathogenesis and bears little relevance to cardiac surgery. Although acute renal failure requiring renal replacement therapy after cardiac surgery is rare, it has a devastating impact on morbidity and mortality, and further studies on protective strategies are essential.

Effect of systemic B-type natriuretic peptide on cardiac vagal motoneuron activity

Intravenous B-type natriuretic peptide (BNP) enhances the bradycardia of reflexes from the heart, including the von Bezold-Jarisch reflex, but its site of action is unknown. The peptide is unlikely to penetrate the blood-brain barrier but could act on afferent or efferent reflex pathways. To investigate the latter, two types of experiment were performed on urethane-anesthetized (1.4 g/kg iv) rats. First, the activity was recorded extracellularly from single cardiac vagal motoneurons (CVMs) in the nucleus ambiguus. CVMs were identified by antidromic activation from the cardiac vagal branch and by their barosensitivity. Phenyl biguanide (PBG), injected via the right atrium in bolus doses of 1-5 mug to evoke the von Bezold-Jarisch reflex, caused a dose-related increase in CVM activity and bradycardia. BNP infusion (25 pmol.kg(-1).min(-1) iv) significantly enhanced both the CVM response to PBG (n = 5 rats) and the reflex bradycardia, but the log-linear relation between those two responses over a range of PBG doses was unchanged by BNP. The reflex bradycardia was not enhanced in five matched time-control rats receiving only vehicle infusions. In five other rats the cervical vagi were cut and the peripheral right vagus was stimulated supramaximally at frequencies of 1-20 Hz. The bradycardic responses to these stimuli were unchanged before, during, and after BNP infusion. We conclude that systemic BNP in a moderate dose enhances the von Bezold-Jarisch reflex activation of CVM, in parallel with the enhanced reflex bradycardia. That enhancement is due entirely to an action before the vagal efferent arm of the reflex pathway.

Nesiritide: a reappraisal of efficacy and safety

The treatment of acute decompensated heart failure (ADHF) remains a therapeutic challenge. Nesiritide was approved by the FDA in 2001 for the treatment of patients with ADHF who have dyspnea at rest or with minimal exertion. Although widely adopted for the treatment of ADHF due to its ability to decrease ventricular filling pressures and to provide mild symptomatic benefit, recent analyses have suggested that nesiritide worsens renal function and increases mortality. Although some discount these analyses that demonstrate the potential dangers of nesiritide, others have stated that its use at the present time must be weighed against the possibility of worse outcomes. A large outcomes trial in patients with ADHF would help clarify the role of nesiritide.

Interactions of Two Monoclonal Antibodies with BNP: High Resolution Epitope Mapping Using Fluorescence Correlation Spectroscopy

Structure-function studies of antibody-antigen systems include the identification of amino acid residues in the antigen that interact with an antibody and elucidation of their individual contributions to binding affinity. We used fluorescence correlation spectroscopy (FCS) and alanine-scanning mutagenesis to characterize the interactions of brain natriuretic peptide (BNP) with two monoclonal antibodies. Human BNP is a 32 amino acid residue long cyclic polypeptide with the ring structure confined between cysteines in positions 10 and 26. It is an important cardiovascular hormone and a valuable diagnostic cardiac marker. We compare the binding strength of the N-terminus Alexa488-labeled BNP, native cyclic BNP, BNP alanine-substituted mutants, linear BNP, and its short fragments to determine the individual contributions of amino acid residues included in the continuous antigenic epitopes that are recognized by two different monoclonal antibodies raised toward BNP. Implementation of FCS for these studies offers all of the advantages of solution phase measurements, including high sensitivity, simplicity of manipulation with reagents, and elimination of solid phase interferences or separation steps. Significant differences in the molecular masses of the free and antibody bound BNP results in a substantial ( approximately 2.5-times) increase in the diffusion rates. Determination of the binding constants and inhibition effects by measuring the diffusion rates of the ligand at the single molecule level introduces the ultimate opportunity for researching systems where the fluorescence intensity and/or fluorescence anisotropy do not change upon interaction of the ligand with the protein. Monoclonal antibodies 106.3 and BC203 demonstrate high affinities to BNP and bind two distant epitopes forming robust antibody sandwiches. Both antibodies are used in Abbott diagnostic assays on AxSYM, IMx, and Architect platforms.

Pharmacoeconomic Modeling of Nesiritide versus Dobutamine for Decompensated Heart Failure

STUDY OBJECTIVE

To model the cost-effectiveness of nesiritide compared with dobutamine in patients with decompensated heart failure.

DESIGN

Cost-effectiveness analysis.

MEASUREMENTS AND MAIN RESULTS

A decision tree model was derived from randomized clinical trial data and data from a previously published economic study. Four cost-effectiveness analyses were performed: analysis 1 -- full probabilistic analysis, repeatedly sampled probabilities for 6-month mortality and hospital readmission from distributions based on 95% confidence intervals (CIs); analysis 2 -- best-case nesiritide analysis, used the limiting values of the 95% CI favorable to nesiritide; analysis 3 -- best-case dobutamine analysis, used the limiting values of the 95% CI favorable to dobutamine; and analysis 4 -- replicated the previously published cost-effectiveness study and served as a methodologic control. Fifty-one consecutive Monte Carlo simulations for cohorts of 1000 hypothetical patients were performed for each analysis. Incremental cost, incremental effectiveness, and incremental cost-effectiveness ratios (ICERs) were calculated for nesiritide versus dobutamine. Analysis 1 showed a mean ICER of 767 US dollars/life-year gained for nesiritide versus dobutamine (incremental cost 251 US dollars +/- 290 US dollars, incremental effectiveness 0.33 +/- 0.22 yr). The 95% confidence region surrounding this point estimate spanned all four quadrants of the incremental cost-effectiveness scatterplot, suggesting inconclusive results. Nesiritide was the dominant treatment strategy in analysis 2 (incremental cost -734 US dollars+/- 106 US dollars, incremental effectiveness 1.19 +/- 0.07 yrs), whereas dobutamine was dominant in analysis 3 (incremental cost 1242 +/- 73 US dollars, incremental effectiveness -0.57 +/- 0.05 yr). Analysis 4 was comparable to the previously published cost-effectiveness analysis (incremental cost -77 +/- 87 US dollars, incremental effectiveness 0.48 +/- 0.05 yr).

CONCLUSIONS

Based on available randomized clinical trial data, nesiritide did not exhibit robust economic superiority over dobutamine. When incorporating the uncertainty (i.e., 95% CIs) in clinical effectiveness as reported in available clinical trial data into the economic analysis, either nesiritide or dobutamine may be the dominant treatment (i.e., more effective at lower cost) for the studied population. Economic analyses of nesiritide and any comparator must account for uncertainty in estimates of cost as well as in clinical effectiveness.

Administration of Nesiritide in Patients after Coronary Artery Bypass Surgery Induces Brisk Diuresis

Recombinant human brain natriuretic peptide, nesiritide, has recently been used in limited studies to enhance postoperative diuresis. A retrospective chart review was conducted at a university hospital to assess the efficacy of nesiritide in cardiac surgery patients with fluid overload refractory to diuretics and dopamine. Nine out of 137 patients who underwent coronary artery bypass grafting at the institution from May 2003 to July 2004 exhibited fluid overload despite diuretics and dopamine. Those who did not respond to the therapy, as manifested by oliguria and heart failure, were started on nesiritide. Urine output, weight change, central venous pressure (CVP), pulmonary artery wedge pressure (PAWP), and serum creatinine were the main outcome measures. Within 6 hours after initiation of nesiritide, the average urine output increased from 28 to 130 mL/h. Serum creatinine levels were not significantly different after 24 hours. The mean CVP decreased from 14 to 10 within 12 hours while the PAWP decreased from 24 to 17 mm Hg. Systemic pressures did not change. One patient had to eventually undergo hemodialysis for complications of renal failure. Our experience demonstrates that infusion of nesiritide in patients with heart failure and fluid overload improves diuresis and hemodynamics without major side effects.

AlbuBNP, a recombinant B-type natriuretic peptide and human serum albumin fusion hormone, as a long-term therapy of congestive heart failure

PURPOSE

B-type natriuretic peptide (BNP) has been in clinical use for the treatment of decompensated congestive heart failure. However, BNP has a very short half-life in circulation, which limits its application to acute CHF and requires continuous i.v. infusion. To provide superior pharmacological benefits of BNP to other stages of chronic congestive heart failure and to eliminate problems associated with drug delivery via continuous i.v. infusion, we have designed and evaluated AlbuBNP, a long-acting form of BNP by recombinant fusion to human serum albumin for use in chronic congestive heart failure, post-acute follow-up, and postmyocardial infarction.

METHODS

Human BNP (1-32) was seamlessly fused to mature human serum albumin at N-terminus to create AlbuBNP. The bioactivities of AlbuBNP were evaluated by natriuretic peptide receptor-A mediated cGMP activation assay, hemodynamic responses, and plasma cGMP elevation. The pharmacokinetic properties were determined after single i.v. or s.c. bolus injection in C57/BL6 mice.

RESULTS

AlbuBNP had approxiamtely the same maximal bioactivity as BNP to activate cGMP in the in vitro NPRA/cGMP assay. The EC50s were 28.4+/-1.2 and 0.46+/-1.1 nM for AlbuBNP and BNP, respectively. In spontaneously hypertensive rats, AlbuBNP lowered both systolic and diastolic blood pressure, having sustainable mean arterial pressure reduction for more than 2 days. Six nmol/kg AlbuBNP i.v. bolus in mice increased plasma cGMP level 5.6-fold over the baseline. The elimination half-life in mice was dramatically increased from 3 min for BNP to 12-19 h for AlbuBNP.

CONCLUSIONS

AlbuBNP is bioactive and has desired pharmacokinetic properties for long-term use. It has the potential to be further developed as a new therapeutic option for chronic, acute, and post-acute CHF to alleviate symptoms, improve clinical status, and slow the disease progression by sustained drug exposure via infrequent simple subcutaneous injections.

Nesiritide added to standard care favorably reduces systolic blood pressure compared with standard care alone in patients with acute decompensated heart failure

The Prospective Randomized Outcomes study of Acutely decompensated Congestive heart failure Treated Initially as Outpatients with Nesiritide (PROACTION) trial evaluated the safety of nesiritide administration in the emergency department in patients with decompensated heart failure. Patients (N=237) were treated for at least 12 hours with standard care plus either intravenous nesiritide or placebo. Compared to placebo, nesiritide favorably decreased systolic blood pressure (SBP) in patients with elevated baseline SBP, without negatively impacting patients with lower baseline SBP (SBP, >140 mm Hg: nesiritide, -28.7 mm Hg, vs placebo, -8.4 mm Hg [P<.001]; SBP, 101-140 mm Hg: nesiritide, -12.3 mm Hg, vs placebo, -5 mm Hg [P<.017]; SBP, <101 mm Hg: nesiritide, -1.2 mm Hg vs placebo, +16.7 mm Hg [P<.03]). Both treatment groups had similar incidences of symptomatic and asymptomatic hypotension. These data demonstrate that early administration of nesiritide in the emergency department is a safe and effective treatment of heart failure.

Cardioprotective functions of atrial natriuretic peptide and B-type natriuretic peptide: a brief review

1. If one was to design a hormone to protect the heart, it would have a number of features shown by the cardiac natriuretic peptides atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP). These hormones are made in cardiomyocytes and are released into the circulation in response to atrial and ventricular stretch, respectively. Atrial natriuretic peptide and BNP can reduce the preload and after-load in normal and failing hearts. They reduce blood volume over the short term by sequestering plasma and over the longer term by promoting renal salt and water excretion and by antagonizing the renin-angiotensin-aldosterone system at many levels. Each of these actions affords indirect benefit to a volume- or pressure-threatened heart. 2. Recent studies have identified additional modes of action of the natriuretic peptides that may also confer cardioprotective benefits, especially in heart disease. The emerging findings are: (i) that ANP and BNP antagonize the cardiac hypertrophic action of angiotensin II and continue working under conditions where endothelial nitric oxide (NO) function is compromised, such as in the presence of high glucose in diabetes; (ii) they potentiate the bradycardia caused by inhibitory ('autoprotective') cardio-cardiac reflexes; and, furthermore, (iii) BNP can suppress cardiac sympathetic nerve activity in humans, including those with heart failure. Thus, it appears that natriuretic peptides can shift sympathovagal balance in a beneficial direction (away from the sympathetic). The vagal reflex and antihypertrophic actions of the peptides are mediated by particulate guanylyl cyclase (pGC) natriuretic peptide receptors. 3. The multiple synergistic actions of the natriuretic peptides make them and their pGC receptors attractive targets for therapy in heart disease. Encouragingly, exogenous natriuretic peptides remain effective even when endogenous peptide levels are raised, as is the case in heart failure. They also remain effective in disease states where other protective mechanisms, such as the NO system, have become ineffective, offering yet further encouragement for the therapeutic use of the natriuretic peptides.

Natriuretic Peptides, Respiratory Disease, and the Right Heart

It is well-recognized that atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) are raised in conditions with ventricular volume and pressure overload. In addition to this established role in left ventricular congestive cardiac failure, there is good evidence that BNP has a diagnostic role in right ventricular (RV) dysfunction and pulmonary arterial hypertension (PAH). For example, BNP levels can be used to differentiate between dyspneic patients with pure respiratory defects and those with RV dysfunction. Studies in patients with PAH have demonstrated significant correlations between BNP levels and mean pulmonary arterial pressure as well as pulmonary vascular resistance. Additionally, BNP has a prognostic role in patients with RV pressure overload and pulmonary hypertension, and it offers a noninvasive test that can be used to guide therapy in patients with PAH. However, although measured plasma proBNP levels are raised in conditions with RV overload, its biological significance is still not well-understood. In this article, we review the general physiologic and potential therapeutic role of natriuretic peptides in respiratory disease, RV dysfunction, and PAH. Furthermore, we assess the various clues toward natriuretic peptide action coming from laboratory studies. ANP and BNP knockout mice develop cardiac fibrosis and hypertrophy. Potentiation of the natriuretic pathway has been shown to reduce cardiac hypertrophy and PAH. This is likely to take place as a result of increased intracellular cyclic guanosine monophosphate levels and subsequent pulmonary vasorelaxant activity. In view of this evidence, there may be a rationale for the therapeutic use of recombinant BNP or neutral endopeptidase inhibitors under conditions of RV dysfunction and PAH.

The natriuretic peptides and their role in disorders of right heart dysfunction and pulmonary hypertension

Atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) are increased in conditions with cardiac ventricular volume and pressure overload. The general physiological and potential therapeutic roles of natriuretic peptides in respiratory disease, right ventricular (RV) dysfunction, and pulmonary arterial hypertension (PAH) are reviewed. BNP levels can be used to differentiate between dyspneic patients with a pure respiratory defect and those with RV dysfunction. BNP levels also correlate with mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) in patients with PAH (atrial septal defect, chronic thromboembolic disease, and scleroderma). BNP is a predictor of mortality in patients with primary pulmonary hypertension (PPH). These are important clinical implications in that a noninvasive blood test may be used to identify high-risk patients for more invasive procedures such as cardiac catheterization. BNP or NT-proBNP measurements may also be used to guide therapy (e.g., pulmonary vasorelaxants) in PAH since upregulation of the natriuretic peptide pathway has been shown to reduce cardiac hypertrophy and PAH. Additionally, there may be therapeutic potential via recombinant BNP or neutral endopeptidase inhibitors in RV dysfunction and PAH.

Nesiritide for Treatment of Heart Failure Due to Right Ventricular Dysfunction

Little information exists regarding the use of nesiritide for treatment of right-sided heart failure. Similarly, little information is available regarding routine use of combination nesiritide and diuretics as initial therapy to relieve edema due to heart failure. Nesiritide may be beneficial in combination with diuretics because it reduces activity of the renin-angiotensin-aldosterone system. It is unclear how potent nesiritide is as a diuretic. Patients exhibit wide variability in clinical response from the diuretic effects of the drug. Two patients were given a combination of nesiritide and diuretics as initial treatment of right-sided heart failure; both experienced significant diuresis and weight loss. Further literature is needed to clarify the role of nesiritide in the treatment of right-sided heart failure.

Implications of the natriuretic peptide system in the pathogenesis of heart failure: diagnostic and therapeutic importance

The natriuretic peptide family consists of at least 3 structurally similar peptides: atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP). Under normal conditions, ANP is synthesized by the atrium and released in response to atrial stretch. This peptide plays an important role in sodium and water homeostasis and is involved in cardiovascular function. In contrast, BNP is synthesized primarily by the ventricles, and its circulatory concentrations are significantly elevated in profound congestive heart failure (CHF). While both plasma levels of ANP and BNP have been found to be increased in patients with various heart diseases, the elevation in circulatory BNP correlates better than ANP with the severity of CHF. Therefore, plasma BNP has been suggested (and lately used) to aid in the accurate diagnosis of heart failure in patients admitted to the emergency room with symptoms of decompensated heart failure. Furthermore, circulatory BNP has been utilized as a prognostic marker in CHF as well as a hormone guide in the evaluation of the efficacy of the conventional treatment of this disease state. In light of the cardiovascular and renal effects of BNP, which most likely exceed those of ANP, the former has been used as a therapeutic agent for the treatment of patients with acute severe CHF. Intravenous infusion of BNP into patients with sustained ventricular dysfunction causes a balanced arterial and venous vasodilatation that has been shown to result in rapid reduction in ventricular filling pressure and reversal of heart failure symptoms, such as dyspnea and acute hemodynamic abnormalities. Thus, the goal of this article is to review the physiology and pathophysiology of natriuretic peptides and the potential use of their circulating levels for diagnosis and treatment of heart failure.

Nesiritide for the treatment of congestive heart failure

Nesiritide (Natrecor) is a recombinant form of the human B-type natriuretic peptide (BNP) that has been shown, through several studies, to have beneficial natriuretic, diuretic and vasodilatory effects in the treatment of congestive heart failure (CHF). Nesiritide mimics the actions of endogenous BNP by binding to and stimulating receptors in the heart, kidney and vasculature. Nesiritide functions as both a potent venous and arterial vasodilator and has been shown to improve cardiac haemodynamics more rapidly and to a greater extent than intravenous nitroglycerin, as well as having fewer side effects. When compared in an open-label trial, nesiritide has also been shown to be less proarrhythmic than dobutamine. The major adverse effect of nesiritide, as with other vasodilators, is symptomatic hypotension, which occurred infrequently in clinical trials. Overall, nesiritide represents an effective and safe therapeutic option for the treatment of decompensated CHF.

Left ventricular diastolic dysfunction and diastolic heart failure

Thirty to fifty percent of patients presenting with signs and symptoms of heart failure have a normal left ventricular (LV) systolic ejection fraction. The clinical examination cannot distinguish these patients (diastolic heart failure) from those with a depressed ejection fraction (systolic heart failure), but echocardiography can. The management of diastolic heart failure has two major objectives. The first is to reverse the consequences of diastolic dysfunction (e.g., venous congestion), and the second is to eliminate or reduce the factors responsible for diastolic dysfunction (e.g., myocardial hypertrophy, fibrosis, and ischemia).

Nesiritide in congestive heart failure associated with acute coronary syndromes: a pilot study of safety and efficacy

BACKGROUND

To compare the safety and efficacy of nesiritide versus intravenous nitroglycerin (NTG) in patients with acute coronary syndromes enrolled in the Vasodilation in the Management of Acute Congestive heart failure trial. Methods and results Retrospective review of Vasodilation in the Management of Acute Congestive heart failure trial data for heart failure associated with prospectively diagnosed acute coronary syndromes. Sixty-one patients were included; 34 received nesiritide and 27 received NTG. Pulmonary capillary wedge pressure was measured in right heart-catheterized patients (11 nesiritide, 9 NTG). Death at 6 months occurred in 2 nesiritide and 5 NTG patients (P>.2). Hypotension occurred in 4 nesiritide and 3 NTG patients (P>.6). At 24 hours, pulmonary capillary wedge pressure improvements persisted (P=.001) in the nesiritide group, whereas the NTG group had returned to baseline (P>.1). In non-right heart-catheterized patients, 24-hour dyspnea scores were at least moderately improved in all nesiritide and 71% of NTG (P=.031). At least minimal dyspnea improvement was seen in 100% of nesiritide versus 71% of NTG patients (P>.3), and 6-hour global clinical scores were at least moderately better in 75% of nesiritide versus 32% of NTG (P=.031). In non-right heart-catheterized patients, there were no 30-day readmissions with nesiritide versus 17% with NTG (P>.2).

CONCLUSIONS

Nesiritide is as safe as NTG in heart failure patients with acute coronary syndromes.

The role of b-type natriuretic peptide in heart failure

The use of BNP as a diagnostic and therapeutic tool in the management of heart failure is promising. Additional studies need to be done regarding the use of BNP as a diagnostic tool to clarify its intrapatient and interpatient variability, especially over time. Nesiritide is the first new intravenous agent for the treatment of acute decompensated heart failure since the introduction of milrinone. It is an effective vasodilator and enhances the effect of concomitant diuretic therapy. Nesiritide may have some benefit on long-term outcomes by prolonging survival, decreasing hospitalizations, or enhancing quality of life. Whether it can or should be used as chronic therapy in end-stage patients remains to be determined.

Brain (B-type) Natriuretic Peptide

Heart failure is the leading cause for hospitalization in the United States, resulting in over $8 billion in costs annually. Over 4.8 million Americans are afflicted with the disease and the number is increasing as the baby boomer generation continues to age. It is imperative that new and innovative modalities of therapy and diagnosis evolve as we continue to redefine the nature of heart failure and discover more about this debilitating disease. This article addresses the implications for endogenous brain (B-type) natriuretic peptide (BNP) testing in patients diagnosed with heart failure as well as the implications for the first available form of exogenous BNP, nesiritide. In addition, the pathophysiology of heart failure and traditional treatment modalities are discussed.

Reversibility of Medically Unresponsive Pulmonary Hypertension with Nesiritide in a Cardiac Transplant Recipient

Pulmonary hypertension unresponsive to medical therapy is considered by most centers to be a contraindication for orthotopic cardiac transplantation. This article describes a patient with unresponsive severe pulmonary hypertension who, despite a combination of maximal doses of dobutamine, milrinone, and nitroprusside infusion, responded to nesiritide (Natrecor) infusion with improvement in pulmonary hemodynamics. The patient was considered a high risk for transplantation because of significant pulmonary hypertension in spite of maximum oral therapy and continuous intravenous milrinone. Severe irreversible pulmonary hypertension persisted with a combination of dobutamine, milrinone, and nitroprusside, with pulmonary artery pressure (PA) of 88/44 mm Hg, a transpulmonary gradient (TPG) of 27, and pulmonary vascular resistance (PVR) of 5.79 Wood units. Upon addition of nesiritide, within 24 hours, there was a sustained decrease in PA to 47/30, TPG of 15, and PVR of 3.75 Wood units. The patient underwent successful left ventricular assist device placement soon after nesiritide infusion demonstrated reversibility of pulmonary hypertension. He subsequently underwent uneventful orthotopic cardiac transplantation and has done well with normal right heart pressures. This case illustrates that addition of nesiritide to standard therapy can reverse significant unresponsive pulmonary hypertension and make a patient eligible for left ventricular assist device and orthotopic cardiac transplantation.

B-type natriuretic peptide in ischemic heart disease

B-type natriuretic peptide (BNP) and the N-terminal fragment of its prohormone (N-proBNP) are released from the heart in response to increased wall stress. Assays for these peptides are now commercially available, and measurement of BNP and N-proBNP is becoming commonplace in patients with suspected heart failure. BNP and N-proBNP facilitate diagnosis and risk stratification in patients with heart failure, and may help guide response to therapy. This review focuses on the emerging role of BNP and N-proBNP measurement in patients with acute coronary syndromes (ACS). Although experimental studies demonstrate rapid BNP release in response to cardiac ischemia, it is unlikely that BNP will be used to diagnose cardiac ischemia, because many other conditions are also associated with modest BNP elevation. In contrast, BNP holds tremendous promise as a prognostic marker in patients with ACS. Studies to date have shown consistently that higher BNP levels are associated with worse clinical outcomes, and that BNP provides unique information to clinical variables, other biomarkers, and left ventricular ejection fraction. Future studies are needed to identify the therapeutic implications of BNP elevation in patients with ACS.

Nesiritide: a review of its use in acute decompensated heart failure

Nesiritide (Natrecor) is a recombinant form of human B-type (brain) natriuretic peptide that has beneficial vasodilatory, natriuretic, diuretic and neurohormonal effects. The drug is administered intravenously for the management of patients with decompensated congestive heart failure (CHF). In the Vasodilation in the Management of Acute Congestive Heart Failure (VMAC) study, patients hospitalised with acute decompensated CHF who received nesiritide had significantly greater mean reductions from baseline in pulmonary capillary wedge pressure 3 hours after starting treatment than nitroglycerin or placebo recipients (-5.8 vs -3.8 and -2 mm Hg, respectively); all patients also received standard therapy (e.g. intravenous diuretics). Improvements in other haemodynamic parameters were also seen in nesiritide recipients. In addition, significantly more nesiritide than placebo recipients reported an improvement in dyspnoea after 3 hours' treatment in VMAC, whereas there was no significant difference between nitroglycerin and placebo recipients. Improvements in global clinical status, dyspnoea and fatigue were also seen with nesiritide in another active-comparator study and in a placebo-controlled study. In VMAC, there was no significant difference between nesiritide and nitroglycerin recipients in 6-month mortality. In the other active-comparator trial, 6-month mortality was significantly lower in recipients of nesiritide 0.015 micro g/kg/min than in dobutamine recipients (although mortality was not a prespecified endpoint and this result should be interpreted with caution). In this same study, the 21-day all-cause hospital readmission rate was significantly lower with nesiritide 0.015 micro g/kg/min than with dobutamine and the duration of active drug treatment was significantly shorter with nesiritide than with dobutamine. Nesiritide is generally well tolerated. In VMAC, significantly more adverse events occurred with nitroglycerin than with nesiritide. The most common adverse events reported during the first 24 hours of therapy in nesiritide and nitroglycerin recipients included general pain, abdominal pain, catheter-related pain, headache, nausea, asymptomatic and symptomatic hypotension, nonsustained ventricular tachycardia and angina pectoris. Most episodes of symptomatic hypotension resolved spontaneously or after an intravenous volume challenge of </=250 ml. In addition, nesiritide does not appear to be proarrhythmic.

CONCLUSION

Short-term intravenous infusion of nesiritide is associated with haemodynamic and symptomatic improvements in patients with acutely decompensated CHF. Nesiritide may offer tolerability and practical advantages over currently used vasodilators, inodilators and inotropes in this condition; in particular, nesiritide does not appear to have proarrhythmic effects. Nesiritide also appears to be effective and well tolerated in patients receiving concomitant beta-blocker therapy and in patients with renal insufficiency. Thus, nesiritide is a suitable first-line option for the treatment of patients with acutely decompensated CHF and is a welcome addition in an area where intravenous agents are few.

Prehospital therapy for acute congestive heart failure: state of the art

Acute congestive heart failure (CHF) is one of the most common syndromes encountered in emergency care settings. Correct diagnosis and treatment for pulmonary edema, the most common acute manifestation of CHF, are of primary importance as misdiagnosis can result in deleterious consequences to patients. The pathogenesis of acute pulmonary edema (APE) is currently believed to arise primarily from the redistribution of intravascular fluid to the lungs secondary to acutely elevated left ventricular (LV) filling pressures. This understanding has provided a basis for the management of acute APE, which entails reduction of LV preload, reduction of LV afterload, ventilatory support, inotropic support as needed, and identification and treatment of other underlying factors contributing to elevated LV filling pressures. The agent most applicable and effective for field treatment is nitroglycerin. Diuretics and morphine should be used with caution, as they carry higher risks, especially in misdiagnosed patients. The role of angiotensin-converting enzyme (ACE) inhibitors has yet to be demonstrated in a prehospital setting. Noninvasive positive pressure ventilation methods are effective adjuncts to current treatment, but their mode of delivery presents technical challenges. The development of novel rapid diagnostic tools, currently in progress, might prove valuable for emergency medical services (EMS) personnel in the future. But for now, EMS personnel must rely on their fundamental skills of history taking and physical examination for accurate diagnosis of CHF.

Examination of the in vivo cardiac electrophysiological effects of nesiritide (human brain natriuretic peptide) in conscious dogs

BACKGROUND

Human brain natriuretic peptide (hBNP) is a new therapeutic agent, nesiritide, indicated in patients with decompensated congestive heart failure, a group at significant risk of developing cardiac arrhythmias. Whether hBNP has cardiac electrophysiologic effects has not been reported.

METHODS AND RESULTS

In 9 healthy, chronically instrumented, conscious dogs, hemodynamic and electrophysiologic parameters were assessed at baseline and during recombinant hBNP (nesiritide) infusion at 0.03 and 0.09 microg/kg/min after 1 hour at each dose. Infusion of hBNP produced dose-related increases (P <.001) in hBNP and cyclic GMP plasma levels and reductions (P <.05) in mean arterial pressure. Mean central venous pressure and sinus cycle length did not change significantly. Infusion of hBNP produced no significant changes in any of the electrophysiologic parameters including no change in surface ECG variables (P wave duration, PR interval, QRS duration, and QTc interval), corrected sinus node recovery time, atrioventricular nodal Wenckebach cycle length, and atrial and ventricular effective refractory periods measured at a 400 ms cycle length. Spontaneous or induced arrhythmias were not observed during hBNP infusion.

CONCLUSIONS

In conscious, healthy dogs, short-term infusion of recombinant hBNP has no significant effects on atrial or ventricular electrophysiologic parameters.

Nesiritide: a new drug for the treatment of decompensated heart failure

Nesiritide, a recombinant human B-type natriuretic peptide, is the first in a new drug class for the treatment of decompensated heart failure. The drug binds to receptors in the vasculature, kidney, adrenal gland, and brain, and overcomes resistance to endogenous BNP present in patients with CHF. Nesiritide administration leads to a rapid and balanced vasodilatory effect, which results in a significant decrease in right and left ventricular filling pressures and systemic vascular resistance and at the same time in an increase in stroke volume and cardiac output without a change in heart rate. These early hemodynamic changes result in a rapid improvement in symptoms of heart failure. In addition, nesiritide lowers aldosterone, catecholamines, and endothelin-1 levels and its effect on the kidney leads to an increased natriuresis and diuresis without effect on serum potassium or renal function. Prior to its approval for clinical use, nesiritide was studied in 10 different clinical trials involving 941 patients with moderate and severe CHF, including elderly patients, patients with both systolic and diastolic dysfunction, and patients with arrhythmias, renal insufficiency, and acute ischemic syndrome. In comparative studies with available vasoactive therapies frequently used for treatment of patients with decompensated heart failure, nesiritide was proven comparable in efficacy to inotropic drugs such as dobutamine, but superior in safety. In a recent study, nesiritide was found to be more effective and better tolerated than the vasodilator, nitroglycerin. The most common side effects expected with the use of nesiritide are headaches and decrease in blood pressure. At the recommended dose of nesiritide, headache was reported during the first 24 hours of treatment in 8% of patients and symptomatic hypotension in 4% of patients, compared to 20% and 5% in nitroglycerin-treated patients.

Divergent effects of ANP and BNP in acute heart failure: evidence for a putative BNP-selective receptor?

OBJECTIVE

Since the pathophysiology of natriuretic peptides in chronic heart failure (HF) is not uniform, we hypothesized that atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) may also have differential effects in acute HF. Our aim was to compare the haemodynamic actions of ANP with BNP, using a classical vasodilator as the control, in greyhound dogs with acute pacing-induced HF.

DESIGN AND METHODS

The right ventricles of eight anaesthetized dogs were paced (193 +/- 4 bpm) until pulmonary capillary pressure (PCP) increased to approximately 15 mmHg. In each animal, according to a randomized within-animal design, haemodynamic responses to equimolar (10 pmol/kg per min) infusions of ANP and BNP were compared with those to sodium nitroprusside (SNP).

RESULTS

Acute pacing alone increased PCP from 6.6 +/- 0.7 to 15.7 +/- 0.3 mmHg, right atrial pressure (RAP) from 1.9 +/- 0.5 to 4.0 +/- 0.6 mmHg, and systemic vascular resistance (SVR) from 1706 +/- 110 to 2179 +/- 106 dyne s/cm5, and reduced cardiac output (CO) from 4.1 +/- 0.4 to 2.5 +/- 0.2 l/min and arterial pressure from 86.1 +/- 2.4 to 74.5 +/- 2.1 mmHg (all P < 0.01). BNP and SNP improved haemodynamics similarly (CO +13 +/- 3% and +9 +/- 5%; PCP -12 +/- 2% and -12 +/- 2%; RAP -28 +/- 9% and -34 +/- 6%, SVR -15 +/- 3% and -11 +/- 3%, all P < 0.01, except CO with SNP, not significant), but effects of BNP on preload outlasted those of SNP. By contrast, ANP did not improve the haemodynamics. Haematocrit was significantly higher during BNP infusion than with ANP (P < 0.05) or with SNP (P < 0.001).

CONCLUSIONS

The haemodynamic responses to exogenous BNP and ANP in acute heart failure were strikingly different. Whereas ANP actions were blunted, BNP response was preserved. Hypothetically, the presence of a putative BNP receptor may explain this finding.

BNP and congestive heart failure

Brain natriuretic peptide (BNP), a peptide hormone secreted chiefly by ventricular myocytes, plays a key role in volume homeostasis. The plasma concentration of BNP is raised in various pathological states, especially heart failure. Many studies suggest that measurement of plasma BNP has clinical utility for excluding a diagnosis of heart failure in patients with dyspnea or fluid retention and for providing prognostic information in those with heart failure or other cardiac disease. It may also be of value in identifying patients after myocardial infarction in whom further assessment of cardiac function is likely to be worthwhile. Preliminary evidence suggests that measuring the plasma concentration of BNP may be useful in fine tuning therapy for heart failure. Artificially raising the circulating levels of BNP shows considerable promise as a treatment for heart failure. With simpler assay methods now available, it is likely that many physicians will measure plasma BNP to aid them in the diagnosis, risk stratification, and monitoring of their patients with heart failure or other cardiac dysfunction.