Assays Specific for BNP1-32 and NT-proBNP Exhibit a Similar Performance to Two Widely Used Assays in the Diagnosis of Heart Failure.

Background: Secretion of cardioprotective B-type natriuretic peptide 1-32 (BNP1-32) is increased proportionately with cardiac dysfunction, but its measurement in plasma is difficult. Therefore, less specific BNP and amino-terminal proBNP (NT-proBNP) assays that detect the precursor molecule proBNP alongside BNP or NT-proBNP metabolites were developed to reflect BNP1-32 secretion and are now mandated in the diagnosis of heart failure (HF). We compared the diagnostic performance of 2 widely used clinical assays: the Roche proBNPII assay, and Abbott BNP assay, against our recently developed in-house assays that measure either intact BNP1-32 or NT-proBNP.

ProBNP That Is Not Glycosylated at Threonine 71 Is Decreased with Obesity in Patients with Heart Failure.

Background: Heart failure (HF) is a leading cause of morbidity and mortality worldwide. Plasma concentrations of B-type natriuretic peptide (BNP) or its amino terminal congener (NT-proBNP) are used for HF diagnosis and risk stratification. Because BNP concentrations are inexplicably lowered in obese patients, we investigated the relationship between proBNP glycosylation, plasma NT-proBNP, and body mass index (BMI) in HF patients.

High-Sensitivity Sandwich ELISA for Plasma NT-proUcn2: Plasma Concentrations and Relationship to Mortality in Heart Failure.

Background: Urocortin 2 (Ucn2) has powerful hemodynamic, renal, and neurohormonal actions and likely participates in normal circulatory homeostasis and the compensatory response to heart failure (HF). A validated assay for endogenous circulating Ucn2 would facilitate investigations into Ucn2 physiology and elucidate its derangement and potential as a biomarker in heart disease.

Method: We developed a chemiluminescence-based sandwich ELISA to measure plasma N-terminal (NT)-proUcn2 in non-HF patients (control; n = 160) and HF patients with reduced (HFREF; n = 134) and preserved (HFPEF; n = 121) left ventricular ejection fraction (LVEF).

Circulating miR-323-3p and miR-652: candidate markers for the presence and progression of acute coronary syndromes.

Background: The prognostic utility of circulating plasma microRNA in patients with acute coronary syndromes (ACS) has been proposed but not yet demonstrated. We set out to investigate circulating microRNA levels in patients incurring recent ACS and examined associations with neurohormones, cardiac structure and function, and survival over 5 years of follow-up.

Methods: An initial screen of 375 microRNAs was performed in 35 ACS patients and 16 healthy controls.

B-type natriuretic peptide forms within the heart, coronary sinus, and peripheral circulation in humans: evidence for degradation before secretion.

Background: The B-type natriuretic peptides (BNP and N-terminal pro-BNP) are secreted by the heart and, in the case of BNP, serve to maintain circulatory homeostasis through renal and vascular actions and oppose many effects of the renin-angiotensin system. Recent evidence suggests that in patients with severe heart failure, circulating immunoreactive BNP is made up mainly of metabolites that may have reduced bioactivity. We hypothesized that BNP may be degraded before it even leaves the heart.

Comparison of immunoassays for NTproBNP conducted on three analysis systems: Milliplex, Elecsys and RIA.

Objectives: The aim of this study was to evaluate a Milliplex NTproBNP immunoassay and to compare its performance with the Roche Elecsys assay and an in house NTproBNP radioimmunoassay (RIA).

Design And Methods: Samples were analyzed for NTproBNP in all 3 assays following the manufacturer's instructions and/or our previously published methodologies.

Results: Similar plasma concentrations and assay reproducibility were observed for the Roche assay and in house RIA.

Central and peripheral forms of C-type natriuretic peptide (CNP): evidence for differential regulation in plasma and cerebrospinal fluid.

Aminoterminal proCNP (NTproCNP), a stable product of CNP gene expression and readily measured in human plasma, provides a new approach to studies of CNP which is rapidly degraded at source. CNP is detectable in human CSF but the presence and proportions of NTproCNP in CSF are unknown. Since CNP is widely expressed throughout the CNS, we hypothesized that the ratio of NTproCNP to CNP in CSF is greatly increased when compared to plasma and that CSF CNP peptides may contribute to their concentrations in the systemic circulation.

B-type natriuretic peptides: looking to the future.

Whereas the role of the cardiac natriuretic peptides, ANP and BNP, in some aspects of physiology and pathophysiology is clear, their potential in diagnosis, prognosis, and therapeutics in many clinical disorders remains uncertain. We predict that circulating levels of these peptides will find increasing diagnostic utility in patients presenting with dyspnoea, in guiding the complex pharmacotherapy in heart failure, and may likewise be useful in guiding the management of patients on chronic maintenance renal dialysis. We predict also that levels of these peptides will be of practical use as prognostic indicators in 'at-risk' populations (such as those with diabetes, coronary heart disease, hypertension, thalassaemia, etc.

Clinical significance of endogenous vasoactive neurohormones in chronic systolic heart failure.

Background: Neurohormonal activation is a pathophysiological hallmark of acute and chronic heart failure (HF). The clinical significance of more recently discovered endogenous vasoactive hormones has not been well-characterized.

Methods And Results: In 154 subjects with stable, chronic systolic HF (New York Heart Association Class I-IV, left ventricular [LV] ejection fraction View Article and Find Full Text PDF

Plasma corin levels provide minimal prognostic utility incremental to natriuretic peptides in chronic systolic heart failure.

Background: Corin is a serine protease that cleaves pro-atrial and pro-B-type natriuretic peptides into biologically active hormones. The relationship between soluble plasma corin levels, plasma natriuretic peptide levels, myocardial structure and performance, and long-term clinical outcomes in the setting of chronic systolic heart failure has not been described.

Methods And Results: In 126 patients with chronic systolic heart failure (left ventricular ejection fraction View Article and Find Full Text PDF

N-terminal pro-B-type natriuretic peptide-guided treatment for chronic heart failure: results from the BATTLESCARRED (NT-proBNP-Assisted Treatment To Lessen Serial Cardiac Readmissions and Death) trial.

Objectives: The purpose of this study was to compare the effects of N-terminal pro-B-type natriuretic peptide (NT-proBNP)-guided therapy with those of intensive clinical management and with usual care (UC) on clinical outcomes in chronic symptomatic heart failure.

Background: Initial trial results suggest titration of therapy guided by serial plasma B-type natriuretic peptide levels improves outcomes in patients with chronic heart failure, but the concept has not received widespread acceptance. Accordingly, we conducted a longer-term study comparing the effects of NT-proBNP-guided therapy with those of intensive clinical management and with UC of patients with heart failure.

Effect of nutrition on plasma C-type natriuretic peptide forms in adult sheep: evidence for enhanced C-type natriuretic peptide degradation during caloric restriction.

Previous studies in lambs and children show that the plasma concentration of amino terminal pro-C-type natriuretic peptide (NTproCNP), a stable product of proCNP, is strongly correlated with skeletal growth and markers of bone formation. Consistent with these findings, CNP expression is sensitive to nutritional status and is reduced by caloric restriction (CR) in both the fetus and the postnatal lamb. However, the effect of nutritional status on CNP in the adult, once linear growth is complete, is unknown.

Urotensin II immunoreactivity in the human circulation: evidence for widespread tissue release.

Background: The sources of secretion and clearance of plasma urotensin II (UII) in the human circulation remain uncertain and may be relevant to understanding the role of UII in human physiology and cardiovascular disease.

Methods: In 94 subjects undergoing clinically indicated cardiac catheterization, we collected blood samples from arterial and multiple venous sites to measure transorgan gradients of plasma UII immunoreactivity.

Results: Net UII release occurred (in descending order of proportional transorgan gradient) across the heart, kidney, head and neck, liver, lower limb, and pulmonary circulations (P < 0.

Skeletal contributions to plasma CNP forms: evidence from regional sampling in growing lambs.

Unlike the cardiac circulating hormones, atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP), C-type natriuretic peptide (CNP) appears to be largely tissue-based and circulates at concentrations considered insufficient to affect organ function. Consistent with CNP's crucial role in regulating skeletal growth, serial studies in juveniles show that both plasma CNP and aminoterminal proCNP (NTproCNP) are highly correlated with growth velocity raising the possibility that skeletal tissues contribute to circulating concentrations of CNP forms during the growing period. Hypothesizing that venous blood draining from bone dense regions is relatively enriched in CNP, we have performed trans-organ regional blood sampling for measurement of CNP forms in 4-week-old lambs and compared the findings to simultaneous levels of ANP and BNP.

Regional release and clearance of C-type natriuretic peptides in the human circulation and relation to cardiac function.

Production and clearance of plasma C-type natriuretic peptide (CNP) and amino terminal (NT)-proCNP immunoreactivity in the human circulation remain poorly characterized. Accordingly, we have measured arterial and venous concentrations of CNP and NT-proCNP across multiple tissue beds during cardiac catheterization in 120 subjects (age: 64.2+/-9.

C-type natriuretic peptide forms in pregnancy: maternal plasma profiles during ovine gestation correlate with placental and fetal maturation.

Circulating concentrations of C-type natriuretic peptide (CNP) and a related amino terminal fragment (NTproCNP) were measured at weekly intervals from preconception to 3 wk postpartum in ewes with twins (n = 8) and nonpregnant ewes (n = 8). In contrast to low and stable values in nonpregnant ewes (CNP, 0.75 +/- 0.

Regional clearance of amino-terminal pro-brain natriuretic peptide from human plasma.

Aims: Mechanisms for clearance of circulating amino-terminal pro-brain natriuretic peptide (NT-proBNP) remain poorly understood and are relevant to the clinical utility of NT-proBNP as a diagnostic and prognostic biomarker in cardiovascular disorders. We sought to determine site(s) of production and clearance of plasma NT-proBNP in the human circulation.

Methods And Results: In 120 subjects undergoing clinically indicated cardiac catheterization, blood samples were collected from arterial and multiple venous sites to measure transorgan gradients of plasma NT-proBNP.

Renal and cardiac function for long-term (10 year) risk stratification after myocardial infarction.

Aims To determine whether combined renal and cardiac function after acute myocardial infarction (MI) predicts 10 year mortality and heart failure (HF). Methods and results Estimated glomerular filtration rate (eGFR), plasma amino terminal pro-brain natriuretic peptide (NT-proBNP), and radionuclide ventriculography were obtained in 1063 patients with MI between 24-96 h of symptom onset. Mortality and HF were documented over follow-up of 9.

Characterization of NT-proBNP in human urine.

Background: Urine amino-terminal probrain natriuretic peptide (NT-proBNP) concentrations may exclude the presence of heart failure and provide insight into renal clearance mechanisms for human NT-proBNP. We characterized the molecular forms of urine NT-proBNP detected by immunoassay.

Methods: Urine from patients with heart failure was subjected to HPLC and analyzed using immunoassays specific toward different epitopes of NT-proBNP.

Intermedin (adrenomedullin-2): a potential protective role in human aortic endothelial cells.

Background/aims: Intermedin (IMD) is a novel peptide with significant vasodilator and cardiac protective actions similar to the related peptide adrenomedullin (ADM). Unlike those of ADM the actions and expression of IMD in endothelial cells are poorly characterised. ADM expression can be increased during cardiovascular disease/stress in vitro and in vivo where it may have a role in several cardiovascular protective actions.

Effect of sex steroids on plasma C-type natriuretic peptide forms: stimulation by oestradiol in lambs and adult sheep.

Although C-type natriuretic peptide (CNP) is crucial to post-natal endochondral growth, roles for the hormone in pubertal bone growth and the physiological effects of sex steroid substitution on CNP synthesis are not known. Using a plasma marker of CNP tissue synthesis (amino-terminal proCNP, NTproCNP), we have studied the effect of exogenous oestrogen (E(2)) or testosterone (T) on plasma CNP forms and bone alkaline phosphatase (bALP) in pre-pubertal lambs. Responses to E(2) in non-cycling adult ewes were also studied.

Transforming growth factor-beta blockade down-regulates the renin-angiotensin system and modifies cardiac remodeling after myocardial infarction.

After myocardial infarction (MI), the heart may undergo progressive ventricular remodeling, resulting in a deterioration of cardiac function. TGF-beta is a key cytokine that both initiates and terminates tissue repair, and its sustained production underlies the development of tissue fibrosis, particularly after MI. We investigated the effects of a novel orally active specific inhibitor of the TGF-beta receptor 1 (SD-208) in an experimental model of MI.

Identification and biological activity of ovine and caprine calcitonin receptor-stimulating peptides 1 and 2.

We have recently reported the isolation of three new members of the calcitonin (CT) gene-related peptide family of peptides, the CT receptor (CT-R)-stimulating peptides (CRSPs). We now report the sequencing and characterization of ovine/caprine CRSP-1 and caprine CRSP-2. Mature ovine and caprine CRSP-1 are identical and have strong structural homology to CRSP-1s identified to date from other species.