Project description:ObjectivesThis study was conducted to determine whether urinary excretion of C-type natriuretic peptide (CNP) is elevated in acute decompensated heart failure (ADHF) and whether elevated levels predict adverse outcomes.BackgroundUrinary CNP has been detected in patients with heart failure, but its clinical significance and prognostic utility, compared to established kidney injury biomarkers, in ADHF is unknown.MethodsWe measured 24-h urinary excretion and concurrent plasma concentrations of CNP22, CNP53, and NT-CNP53 in 58 ADHF patients and 20 healthy control subjects. Urinary kidney injury molecule (KIM)-1 and neutrophil gelatinase–associated lipocalin (NGAL) and plasma N-terminal pro-B type natriuretic peptide (NT-proBNP) were also measured. Mortality and all-cause rehospitalization/death were assessed over a follow-up of 1.5 ± 0.9 years.ResultsADHF patients had higher urinary excretion of all 3 CNP molecular forms than did controls. Plasma CNP22 and CNP53 were elevated in ADHF but showed limited correlation with urinary excretion, suggesting that mainly renal-derived CNP appears in urine. Plasma NT-proBNP and urinary KIM-1 were also elevated in ADHF (p < 0.0001); urinary NGAL was similar to that in controls. At 6 months, event-free survival values in ADHF patients were 86% for mortality and 59% for all-cause rehospitalization/death. On Cox regression analysis, urinary NT-CNP53 was the only predictor of mortality (hazard ratio: 1.7; 95% confidence interval: 1.1 to 2.4; p = 0.01) and all-cause rehospitalization/death (hazard ratio: 1.8; 95% confidence interval: 1.3 to 2.4; p = 0.0004), even after adjustment. Integrated discrimination analysis suggested that urinary NT-CNP53 combined with plasma NT-proBNP improved the prediction of adverse outcomes.ConclusionsThe findings from this study support the clinical utility of urinary CNP molecular forms. In ADHF, urinary NT-CNP53 correlated with prognosis, better predicted outcomes than did urinary NGAL and KIM-1, and improved the prognostic value of plasma NT-proBNP.
Project description:BACKGROUND:The GUIDE-IT (GUIDing Evidence Based Therapy Using Biomarker Intensified Treatment in Heart Failure) trial prospectively compared the efficacy of an N-terminal pro-B-type natriuretic peptide (NT-proBNP)-guided heart failure treatment strategy (target NT-proBNP level <1,000 pg/ml) with optimal medical therapy alone in high-risk patients with heart failure and reduced ejection fraction. When the study was stopped for futility, 894 patients had been enrolled. OBJECTIVES:The purpose of this study was to assess treatment-related quality-of-life (QOL) and economic outcomes in the GUIDE-IT trial. METHODS:The authors prospectively collected a battery of QOL instruments at baseline and 3, 6, 12, and 24 months post-randomization (collection rates 90% to 99% of those eligible). The principal pre-specified QOL measures were the Kansas City Cardiomyopathy Questionnaire (KCCQ) Overall Summary Score and the Duke Activity Status Index (DASI). Cost data were collected for 735 (97%) U.S. PATIENTS: RESULTS:Baseline variables were well balanced in the 446 patients randomized to the NT-proBNP-guided therapy and 448 to usual care. Both the KCCQ and the DASI improved over the first 6 months, but no evidence was found for a strategy-related difference (mean difference [biomarker-guided - usual care] at 24 months of follow-up 2.0 for DASI [95% confidence interval (CI): -1.3 to 5.3] and 1.1 for KCCQ [95% CI: -3.7 to 5.9]). Total winsorized costs averaged $5,919 higher in the biomarker-guided strategy (95% CI: -$1,795, +$13,602) over 15-month median follow-up. CONCLUSIONS:A strategy of NT-proBNP-guided HF therapy had higher total costs and was not more effective than usual care in improving QOL outcomes in patients with heart failure and a reduced ejection fraction. (Guiding Evidence Based Therapy Using Biomarker Intensified Treatment [GUIDE-IT]; NCT01685840).
Project description:ObjectivesThe purpose of the present study was to translate our laboratory investigations to establish safety and efficacy of 8 weeks of chronic SC B-type natriuretic peptide (BNP) administration in human Stage C heart failure (HF).BackgroundB-Type natriuretic peptide is a cardiac hormone with vasodilating, natriuretic, renin-angiotensin inhibiting, and lusitropic properties. We have previously demonstrated that chronic cardiac hormone replacement with subcutaneous (SC) administration of BNP in experimental HF resulted in improved cardiovascular function.MethodsWe performed a randomized double-blind placebo-controlled proof of concept study comparing 8 weeks of SC BNP (10 μg/kg bid) (n = 20) with placebo (n = 20) in patients with ejection fraction <35% and New York Heart Association functional class II to III HF. Primary outcomes were left ventricular (LV) volumes and LV mass determined by cardiac magnetic resonance imaging. Secondary outcomes include LV filling pressure by Doppler echo, humoral function, and renal function.ResultsEight weeks of chronic SC BNP resulted in a greater reduction of LV systolic and diastolic volume index and LV mass index as compared with placebo. There was a significantly greater improvement of Minnesota Living with Heart Failure score, LV filling pressure as demonstrated by the reductions of E/e' ratio, and decrease in left atrial volume index as compared with placebo. Glomerular filtration rate was preserved with SC BNP, as was the ability to activate plasma 3',5'-cyclic guanosine monophosphate (p < 0.05 vs. placebo).ConclusionsIn this pilot proof of concept study, chronic protein therapy with SC BNP improved LV remodeling, LV filling pressure, and Minnesota Living with Heart Failure score in patients with stable systolic HF on optimal therapy. Renin-angiotensin was suppressed, and glomerular filtration rate was preserved. Subcutaneous BNP represents a novel, safe, and efficacious protein therapeutic strategy in human HF. Further studies are warranted to determine whether these physiologic observations can be translated into improved clinical outcomes and ultimately delay the progression of HF. (Cardiac Hormone Replacement With BNP in Heart Failure: A Novel Therapeutic Strategy; NCT00252187).
Project description:BackgroundSeveral aggregate data meta-analyses suggest that treatment guided by the serum concentration of natriuretic peptides (B-type natriuretic peptide (BNP) or its derivative N-terminal pro-B-type natriuretic peptide (NT-BNP)) reduces all-cause mortality compared with usual care in patients with heart failure (HF). We propose to conduct a meta-analysis using individual participant data (IPD) to estimate the effect of BNP-guided therapy on clinical outcomes, and estimate the extent of effect modification for clinically important subgroups.MethodsWe will use standard systematic review methods to identify relevant trials and assess study quality. We will include all randomized controlled trials (RCTs) of BNP-guided treatment for HF that report a clinical outcome. The primary outcome will be time to all-cause mortality. We will collate anonymized, individual patient data into a single database, and carry out appropriate data checks. We will use fixed-effects and random-effects meta-analysis methods to combine hazard ratios (HR) estimated within each RCT, across all RCTs. We will also include a meta-analysis and meta-regression analyses based on aggregate data, and combine IPD with aggregate data if we obtain IPD for a subset of trials.DiscussionThe IPD meta-analysis will allow us to estimate how patient characteristics modify treatment benefit, and to identify relevant subgroups of patients who are likely to benefit most from BNP-guided therapy. This is important because aggregate meta-analyses have suggested that clinically relevant subgroup effects exist, but these analyses have been unable to quantify the effects reliably or precisely.Trials registrationPROSPERO 2013: CRD42013005335.
Project description:Dilated cardiomyopathy is a major cause of heart failure (HF) that affects millions. Corin cleaves and biologically activates pro-atrial natriuretic peptide (pro-ANP) and pro-B-type natriuretic peptide (pro-BNP). High corin levels reduce the development of systolic dysfunction and HF in experimental dilated cardiomyopathy. Yet, patients with significant HF unexpectedly show low corin levels with high plasma ANP/BNP levels. Therefore, we examined the relationship between cardiac corin expression, ANP/BNP levels, and the stages of HF. We used a well-established, dilated cardiomyopathy model to evaluate gene and protein expression as mice longitudinally developed Stages A-D HF. Cardiac systolic function (ejection fraction) continuously declined over time (P<0.001). Cardiac corin transcripts were decreased at early Stage B HF and remained low through Stages C and D (P<0.001). Cardiac corin levels were positively correlated with systolic function (r=0.96, P=0.003) and inversely with lung water (r=-0.92, P=0.001). In contrast, cardiac pro-ANP/BNP transcripts increased later (Stages C and D) and plasma levels rose only with terminal HF (Stage D, P<0.001). Immunoreactive plasma ANP and BNP levels were positively associated with plasma cyclic guanosine monophosphate levels (r=0.82, P=0.01 and r=0.8, P=0.02, respectively). In experimental dilated cardiomyopathy, corin levels declined early with progressive systolic dysfunction before the development of HF, whereas significant increases in plasma ANP, BNP, and cyclic guanosine monophosphate levels were found only in later stage (C and D) HF. This dyssynchrony in expression of corin versus ANP/BNP may impair cleavage activation of pro-natriuretic peptides, and thereby promote the transition from earlier to later stage HF.
Project description:BACKGROUND:Circulating B-type natriuretic peptide (BNP) concentrations strongly predict mortality in patients with heart failure (HF). Both cardiac and extracardiac stimuli influence BNP levels, suggesting that BNP might have similar prognostic value in patients without HF. OBJECTIVES:The aim of this study was to compare the prognostic value of BNP between patients with and those without HF. METHODS:Using the Vanderbilt University Medical Center electronic health record, 30,487 patients (median age 63 years, 50% men, 17% black, 38% with HF) who had a first plasma BNP measurement between 2002 and 2013, with follow-up through 2015, were studied. The risk for death according to BNP level was quantified using multivariate Cox proportional hazards models. RESULTS:BNP levels were lower in patients without HF (median 89 pg/ml; interquartile range: 34 to 238 pg/ml) compared with those with HF (median 388 pg/ml; interquartile range: 150 to 940 pg/ml) (p < 0.0001). Over 90,898 person-years of follow-up, 5,903 patients without HF (31%) and 6,181 patients with HF (53%) died. In multivariate models including demographic and clinical characteristics, BNP and age were the strongest predictors of death in both patients with and those without HF. In acute care settings and even among outpatients with modestly elevated BNP, the risk for death according to BNP was similar between patients with and those without HF. For instance, a BNP level of 400 pg/ml was associated with a 3-year risk for death of 21% (95% confidence interval: 20% to 23%) and 19% (95% confidence interval: 17% to 20%) in patients with and those without HF, respectively. CONCLUSIONS:Among patients without HF, plasma BNP level is a stronger predictor of death than traditional risk factors. The risk for death associated with any given BNP level is similar between patients with and those without HF, particularly in the acute care setting.
Project description:ObjectiveTo evaluate the performance of B-type natriuretic peptide as a diagnostic tool for heart failure in pregnant or postpartum women with singleton gestations.MethodsWe conducted a retrospective study of diagnostic accuracy. We identified pregnant and postpartum women with B-type natriuretic peptide and echocardiography performed at an obstetric teaching hospital from 2007 to 2018. Women with known cardiac disease or multiple gestation were excluded. A panel of two cardiovascular disease experts, blinded to B-type natriuretic peptide values, determined the diagnosis of heart failure by consensus. Their judgement was based on detailed clinical features and parameters at the time of presentation with suspected heart failure. Where consensus could not be reached, differences were adjudicated by a third expert. A receiver operating characteristic curve estimated the sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of B-type natriuretic peptide at various thresholds.ResultsIn total, 22 pregnant and 38 postpartum women were included in the cohort. Average age was 32±6.8 years. The most common clinical features at the time of presentation with suspected heart failure included preeclampsia (33/60, 55%), dyspnea (50/60, 83%), chest discomfort (34/60, 58%), and bilateral lower extremity edema (32/60, 53%). In total, 39 (65%) women had heart failure. The median B-type natriuretic peptide level was 326 pg/mL (interquartile range 200.5-390.5) in women with heart failure, as compared with 75.5 pg/mL (interquartile range 19-245) in women without heart failure (P<.01). The estimated optimal B-type natriuretic peptide cutoff was 111 (95% CI 78-291) pg/mL. Using this threshold, 45 (75%) women had an elevated B-type natriuretic peptide, which yielded a 95% sensitivity (95% CI 83-99), 62% specificity (95% CI 38-82), a positive likelihood ratio of 2.5 (95% CI 1.4-4.3), and a negative likelihood ratio of 0.1 (95% CI 0.0-0.3) for heart failure.ConclusionsB-type natriuretic peptide is a useful clinical tool to evaluate pregnant and postpartum women with suspected heart failure.
Project description:BackgroundWe have reported that pro-B-type natriuretic peptide (BNP)-1-108 circulates and is processed to mature BNP1-32 in human blood. Building on these findings, we sought to determine whether proBNP1-108 processed forms in normal circulation are biologically active and stimulate cGMP, and whether proBNP1-108 processing and activity are altered in human heart failure (HF) compared with normal. Because BNP1-32 is deficient whereas proBNP1-108 is abundant in HF, we hypothesize that proBNP1-108 processing and degradation are impaired in HF patients ex vivo.Methods and resultsWe measured circulating molecular forms, including BNP1-32, proBNP1-108, and N-terminal-proBNP, and all were significantly higher in patients with HF when compared with that in normals. Fresh serum samples from normals or patients with HF were incubated with or without exogenous nonglycosylated proBNP1-108 tagged with 6 C-terminal Histidines to facilitate peptide isolation. His-tag proBNP1-108 was efficiently processed into BNP1-32/3-32 at 5 minutes in normal serum, persisted for 15 minutes, then disappeared. Delayed processing of proBNP1-108 was observed in HF samples, and the degradation pattern differed depending on left ventricular function. The 5-minute processed forms from both normal and HF serums were active and generated cGMP via guanylyl cyclase-A receptors; however, the 180-minute samples were not active. The proBNP1-108 processing enzyme corin and BNP-degrading enzyme dipeptidyl peptidase-4 were reduced in HF versus normal, perhaps contributing to differential BNP metabolism in HF.ConclusionsExogenous proBNP1-108 is processed into active BNP1-32 and ultimately degraded in normal circulation. The processing and degradation of BNP molecular forms were altered but complete in HF, which may contribute to the pathophysiology of HF.
Project description: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.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.
Project description:The discovery of the heart as an endocrine organ resulted in a remarkable recognition of the natriuretic peptide system (NPS). Specifically, research has established the production of atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) from the heart, which exert pleiotropic cardiovascular, endocrine, renal, and metabolic actions via the particulate guanylyl cyclase A receptor (GC-A) and the second messenger, cGMP. C-type natriuretic peptide (CNP) is produced in the endothelium and kidney and mediates important protective auto/paracrine actions via GC-B and cGMP. These actions, in part, participate in the efficacy of sacubitril/valsartan in heart failure (HF) due to the augmentation of the NPS. Here, we will review important insights into the biology of the NPS, the role of precision medicine, and focus on the phenotypes of human genetic variants of ANP and BNP in the general population and the relevance to HF. We will also provide an update of the existence of NP deficiency states, including in HF, which provide the rationale for further therapeutics for the NPS. Finally, we will review the field of peptide engineering and the development of novel designer NPs for the treatment of HF. Notably, the recent discovery of a first-in-class small molecule GC-A enhancer, which is orally deliverable, will be highlighted. These innovative designer NPs and small molecule possess enhanced and novel properties for the treatment of HF and cardiovascular diseases.