The Role of Natriuretic Peptides as Biomarkers for Guiding the Management of Chronic Heart Failure

Biomarkers of HFpEF: Natriuretic Peptides, High-Sensitivity Troponins and Beyond

Heart failure (HF) is a significant cause of morbidity and mortality worldwide. HF with preserved ejection fraction (HFpEF) is a complex syndrome, often participated by several cardiac and extracardiac conditions, including chronic kidney disease, pulmonary disease, anaemia and advanced age. Circulating biomarkers reflecting pathophysiological pathways involved in HFpEF development and progression may assist clinicians in early diagnosis and management of this condition. Natriuretic peptides (NPs) are cardioprotective hormones released by cardiomyocytes in response to pressure or volume overload and in response to activation of neuro-endocrine-immune system. The relevance of B-type NP (BNP) and N-terminal pro-B-type NP (NT-proBNP) for diagnosis and risk stratification has been extensively demonstrated, and these biomarkers are emerging tools for population screening and as guides to the start of treatment in subclinical HF. On the contrary, conflicting evidence exists on the value of NPs to guide HF therapy. Among the other biomarkers, high-sensitivity troponins and soluble suppression of tumorigenesis-2 are the most promising biomarkers for risk stratification, predicting outcome independently from NPs. In this review, some novel biomarkers are being tested in such clinical scenario, more tightly linked to specific pathophysiological processes of cardiac damage.

Transient Receptor Potential Channels, Natriuretic Peptides, and Angiotensin Receptor-Neprilysin Inhibitors in Patients With Heart Failure

Heart failure (HF) remains the leading cause of death, morbidity, and medical expenses worldwide. Treatments for HF with reduced ejection fraction have progressed in recent years; however, acute decompensated heart failure remains difficult to treat. The transient receptor potential (TRP) channel family plays roles in various cardiovascular diseases, responding to neurohormonal and mechanical load stimulation. Thus, TRP channels are promising targets for drug discovery, and many studies have evaluated the roles of TRP channels expressed on pain neurons. The natriuretic peptide (NP) family of proteins regulates blood volume, natriuresis, and vasodilation and can antagonize the renin-angiotensin-aldosterone system and participate in the pathogenesis of major cardiovascular diseases, such as HF, coronary atherosclerotic heart disease, and left ventricular hypertrophy. NPs are degraded by neprilysin, and the blood level of NPs has predictive value in the diagnosis and prognostic stratification of HF. In this review, we discuss the relationships between typical TRP family channels (e.g., transient receptor potential cation channel subfamily V member 1 andTRPV1, transient receptor potential cation channel subfamily C member 6) and the NP system (e.g., atrial NP, B-type NP, and C-type NP) and their respective roles in HF. We also discuss novel drugs introduced for the treatment of HF.

Prognostic Value of Natriuretic Peptides for All-Cause Mortality, Right Ventricular Failure, Major Adverse Events, and Myocardial Recovery in Advanced Heart Failure Patients Receiving a Left Ventricular Assist Device: A Systematic Review

Aims: Major adverse event (MAE) rates during left ventricular assist device (LVAD) therapy in advanced heart failure (HF) patients are high, and impair quality of life and survival. Prediction and risk stratification of MAEs in order to improve patient selection and thereby outcome during LVAD therapy is therefore warranted. Circulating natriuretic peptides (NPs) are strong predictors of MAEs and mortality in chronic HF patients. However, whether NPs can identify patients who are at risk of MAEs and mortality or tend toward myocardial recovery after LVAD implantation is unclear. The aim of this systematic review is to analyze the prognostic value of circulating NP levels before LVAD implantation for all-cause mortality, MAEs and myocardial recovery after LVAD implantation.

Methods and Results: Electronic databases were searched for studies analyzing circulating NP in adults with advanced HF before LVAD implantation in relation to mortality, MAEs, or myocardial recovery after LVAD implantation. Twenty-four studies published between 2008 and 2021 were included. Follow-up duration ranged from 48 hours to 5 years. Study sample size ranged from 14 to 15,138 patients. Natriuretic peptide levels were not predictive of all-cause mortality. However, NPs were predictive of right ventricular failure (RVF) and MAEs such as ventricular arrhythmias, moderate or severe aortic regurgitation, and all-cause rehospitalization. No relation between NPs and myocardial recovery was found.

Conclusion: This systematic review found that NP levels before LVAD implantation are not predictive of all-cause mortality after LVAD implantation. Thus, NP levels may be of limited value in patient selection for LVAD therapy. However, NPs help in risk stratification of MAEs and may be used to identify patients who are at risk for RVF, ventricular arrhythmias, moderate or severe aortic regurgitation, and all-cause rehospitalization after LVAD implantation.

Neurohumoral, cardiac and inflammatory markers in the evaluation of heart failure severity and progression

Heart failure is common in adult population, accounting for substantial morbidity and mortality worldwide. The main risk factors for heart failure are coronary artery disease, hypertension, obesity, diabetes mellitus, chronic pulmonary diseases, family history of cardiovascular diseases, cardiotoxic therapy. The main factor associated with poor outcome of these patients is constant progression of heart failure. In the current review we present evidence on the role of established and candidate neurohumoral biomarkers for heart failure progression management and diagnostics. A growing number of biomarkers have been proposed as potentially useful in heart failure patients, but not one of them still resembles the characteristics of the “ideal biomarker.” A single marker will hardly perform well for screening, diagnostic, prognostic, and therapeutic management purposes. Moreover, the pathophysiological and clinical significance of biomarkers may depend on the presentation, stage, and severity of the disease. The authors cover main classification of heart failure phenotypes, based on the measurement of left ventricular ejection fraction, including heart failure with preserved ejection fraction, heart failure with reduced ejection fraction, and the recently proposed category heart failure with mid-range ejection fraction. One could envisage specific sets of biomarker with different performances in heart failure progression with different left ventricular ejection fraction especially as concerns prediction of the future course of the disease and of left ventricular adverse/reverse remodeling. This article is intended to provide an overview of basic and additional mechanisms of heart failure progression will contribute to a more comprehensive knowledge of the disease pathogenesis.

Pathophysiology and significance of natriuretic peptides in patients with end-stage kidney disease

Natriuretic peptides (NP), especially B type (BNP) and its N-terminal pro-B type natriuretic peptide (NT-proBNP), have long been regarded as biomarkers of volume overload and tools to exclude heart failure in the general population. However, their role in end-stage kidney disease (ESKD) is less certain given that BNP and NT-proBNP are excreted by the kidney and so serum concentrations of NPs are nearly universally elevated compared to controls. Nevertheless, the accumulated evidence suggests thatserum concentrations of NPs in patients with ESKD show moderate or strong positive relationships with underlying heart disease, abnormal cardiac structure or function and mortality. Limited evidence also supports the role of BNP including NT-proBNP, ANP in some studies, rather than CNP or DNP in risk stratification among ESKD patients as well as the utility of BNP samplings pre- and post- hemodialysis. However, studies of the cut-off values of NPs have yielded inconsistent results, such that further large-scale studies are needed to clarify these issues. This review summarizes the pathophysiology and significance of NPs in ESKD patients, especially their potential role as risk stratification biomarkers in clinical management.

Natriuretic Peptide Response and Outcomes in Chronic Heart Failure With Reduced Ejection Fraction

BACKGROUND

The GUIDE-IT (GUIDing Evidence Based Therapy Using Biomarker Intensified Treatment in Heart Failure) trial demonstrated that a strategy to "guide" application of guideline-directed medical therapy (GDMT) by reducing amino-terminal pro-B-type natriuretic peptide (NT-proBNP) was not superior to GDMT alone.

OBJECTIVES

The purpose of this study was to examine the prognostic meaning of NT-proBNP changes following heart failure (HF) therapy intensification relative to the goal NT-proBNP value of 1,000 pg/ml explored in the GUIDE-IT trial.

METHODS

A total of 638 study participants were included who were alive and had available NT-proBNP results 90 days after randomization. Rates of subsequent cardiovascular (CV) death/HF hospitalization or all-cause mortality during follow-up and Kansas City Cardiomyopathy Questionnaire (KCCQ) overall scores were analyzed.

RESULTS

A total of 198 (31.0%) subjects had an NT-proBNP ≤1,000 pg/ml at 90 days with no difference in achievement of NT-proBNP goal between the biomarker-guided and usual care arms. NT-proBNP ≤1,000 pg/ml by 90 days was associated with longer freedom from CV/HF hospitalization or all-cause mortality (p < 0.001 for both) and lower adjusted hazard of subsequent HF hospitalization/CV death (hazard ratio: 0.26; 95% confidence interval: 0.15 to 0.46; p < 0.001) and all-cause mortality (hazard ratio: 0.34; 95% confidence interval: 0.15 to 0.77; p = 0.009). Regardless of elevated baseline concentration, an NT-proBNP ≤1,000 pg/ml at 90 days was associated with better outcomes and significantly better KCCQ overall scores (p = 0.02).

CONCLUSIONS

Patients with heart failure with reduced ejection fraction whose NT-proBNP levels decreased to ≤1,000 pg/ml during GDMT had better outcomes. These findings may help to understand the results of the GUIDE-IT trial. (Guiding Evidence Based Therapy Using Biomarker Intensified Treatment [GUIDE-IT]; NCT01685840).

Towards Point-of-Care Heart Failure Diagnostic Platforms: BNP and NT-proBNP Biosensors

Heart failure is a class of cardiovascular diseases that remains the number one cause of death worldwide with a substantial economic burden of around $18 billion incurred by the healthcare sector in 2017 due to heart failure hospitalization and disease management. Although several laboratory tests have been used for early detection of heart failure, these traditional diagnostic methods still fail to effectively guide clinical decisions, prognosis, and therapy in a timely and cost-effective manner. Recent advances in the design and development of biosensors coupled with the discovery of new clinically relevant cardiac biomarkers are paving the way for breakthroughs in heart failure management. Natriuretic neurohormone peptides, B-type natriuretic peptide (BNP) and N-terminal prohormone of BNP (NT-proBNP), are among the most promising biomarkers for clinical use. Remarkably, they result in an increased diagnostic accuracy of around 80% owing to the strong correlation between their circulating concentrations and different heart failure events. The latter has encouraged research towards developing and optimizing BNP biosensors for rapid and highly sensitive detection in the scope of point-of-care testing. This review sheds light on the advances in BNP and NT-proBNP sensing technologies for point-of-care (POC) applications and highlights the challenges of potential integration of these technologies in the clinic. Optical and electrochemical immunosensors are currently used for BNP sensing. The performance metrics of these biosensors-expressed in terms of sensitivity, selectivity, reproducibility, and other criteria-are compared to those of traditional diagnostic techniques, and the clinical applicability of these biosensors is assessed for their potential integration in point-of-care diagnostic platforms.

Cardiovascular Risk Assessment for Noncardiac Surgery: Are We Ready for Biomarkers?

Biomarkers aided perioperative cardiac assessment is a relatively new concept. Cardiac biomarkers with historical significance (aspartate transaminase, dehydrogenase, creatinine kinase and myoglobin) have paved the way for traditional biomarkers (cardiac troponin, C-reactive protein, lipoprotein). Contemporary biomarkers like natriuretic peptides (BNP and ProBNP) are validated risk markers in both acute and chronic cardiac diseases and are showing remarkable promise in predicting serious cardiovascular complications after non-cardiac surgery. This review is intended to provide a critical overview of traditional and contemporary biomarkers for perioperative cardiovascular assessment and management. This review also discusses the potential utility of newer biomarkers like galectin-3, sST-2, GDF-15, TNF-alpha, MiRNAs and many others that can predict inflammation, cardiac remodeling, injury and endogenous stress and need further investigations to establish their clinical utility. Though promising, biomarker led perioperative care is still in infancy and it has not been determined that it can improve clinical outcomes.

Improved outcome with standardized plan for clinical management of acute decompensated chronic heart failure

Background

Our overall goal is to improve clinical care for inpatients with chronic heart failure (CHF). A retrospective assessment of CHF patients admitted to our hospital over the past decade (2005 vs. 2014) indicated a need for better strategies to evaluate clinical treatment, implement best practices and achieve optimal patient outcome. To that purpose, we developed a standardized plan to improve in-hospital treatment of acute decompensated CHF patients.

Methods & Results

Retrospective chart reviews were conducted to compare three cohorts of CHF patients admitted to the University Hospital of Lund at different time points over a 12-year period: 2005 (365 patients), 2014 (172 patients) and 2017-2018 (57 patients). Little improvement was seen between 2005 and 2014 with respect to one-year mortality (35% vs. 34%) and adequate treatment with recommended medications, e.g., use of renin-angiotensin system blockers (45% vs. 51%). A standardized treatment plan was devised to improve outcomes. A third cohort, treated under the plan (2017-2018), was compared with the 2014 cohort. One-year mortality (18% vs. 34%) and 30-day readmission (5% vs. 30%) were dramatically decreased, and adherence to medication guidelines was achieved. Key elements of the plan included well-defined treatment procedures, enhanced communication and teamwork, education, adequate time for treatment (5 days) and post-discharge follow-up as necessary. Natriuretic peptide (NT-proBNP) levels were useful for assessing patient status, prognosis and response to treatment.

Conclusion

Development of a standard plan for clinical management of acute decompensated CHF patients resulted in significant improvements in patient outcome, as reflected in decreased rates of 30-day readmission and one-year mortality.

Natriuretic peptides in heart failure: Current achievements and future perspectives

The last two centuries have witnessed countless discoveries in the field of medicine that found their roots in the up growing development of technology as well as in the visionary ideas of brilliant scientists and research groups. One of the most important discoveries in the field of cardiovascular medicine allowed to break the paradigm identifying the heart with mere mechanical pump and to characterize its intriguing endocrine properties. Indeed, the discovery of hormones produced by the cardiac chambers, the natriuretic peptides, represents one of the milestones of the current conception of complexity of integrated human physiology. In the last four decades, the role of these hormones in the regulation of the cardiovascular system, in physiology and diseases, has been defined piece after piece. From diagnostic and prognostic markers, natriuretic peptides have become one of the most relevant clinical biomarker and a reliable target for establishing the efficacy of therapies. Recently and successfully, natriuretic peptide-based strategies are proposed as therapeutic weapons to improve outcome in heart failure. The future will witness potential further therapeutic application of natriuretic peptides that are currently being actively investigated.

A review on B-type natriuretic peptide monitoring: assays and biosensors

Since its discovery in 1988, B-type natriuretic peptide (BNP) has been recognized as a powerful cardiovascular biomarker for a number of disease states, specifically heart failure. Concurrent with such a discovery, much effort has been allocated to the precise monitoring of physiological BNP levels. Thus, it can be used to guide the therapy of heart failure and determine the patient's stage of disease. Thus, we discuss in this article BNP as a potent biomarker. Subsequently, we will review the progress of biosensing devices as they could be applied to monitor BNP levels as assays, benchtop biosensors and implantable biosensors. The analytical characteristics of commercially available BNP assays are presented. Still emerging as a field, we define four obstacles that present opportunity for the future development of implantable biosensor: foreign body response, sensor renewability, sensitivity and selectivity.

2017 Comprehensive Update of the Canadian Cardiovascular Society Guidelines for the Management of Heart Failure

Since the inception of the Canadian Cardiovascular Society heart failure (HF) guidelines in 2006, much has changed in the care for patients with HF. Over the past decade, the HF Guidelines Committee has published regular updates. However, because of the major changes that have occurred, the Guidelines Committee believes that a comprehensive reassessment of the HF management recommendations is presently needed, with a view to producing a full and complete set of updated guidelines. The primary and secondary Canadian Cardiovascular Society HF panel members as well as external experts have reviewed clinically relevant literature to provide guidance for the practicing clinician. The 2017 HF guidelines provide updated guidance on the diagnosis and management (self-care, pharmacologic, nonpharmacologic, device, and referral) that should aid in day-to-day decisions for caring for patients with HF. Among specific issues covered are risk scores, the differences in management for HF with preserved vs reduced ejection fraction, exercise and rehabilitation, implantable devices, revascularization, right ventricular dysfunction, anemia, and iron deficiency, cardiorenal syndrome, sleep apnea, cardiomyopathies, HF in pregnancy, cardio-oncology, and myocarditis. We devoted attention to strategies and treatments to prevent HF, to the organization of HF care, comorbidity management, as well as practical issues around the timing of referral and follow-up care. Recognition and treatment of advanced HF is another important aspect of this update, including how to select advanced therapies as well as end of life considerations. Finally, we acknowledge the remaining gaps in evidence that need to be filled by future research.

Heart failure with reduced ejection fraction

Heart failure is a global public health problem that affects more than 26 million people worldwide. The global burden of heart failure is growing and is expected to increase substantially with the ageing of the population. Heart failure with reduced ejection fraction accounts for approximately 50% of all cases of heart failure in the United States and is associated with substantial morbidity and reduced quality of life. Several diseases, such as myocardial infarction, certain infectious diseases and endocrine disorders, can initiate a primary pathophysiological process that can lead to reduced ventricular function and to heart failure. Initially, ventricular impairment is compensated for by the activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system, but chronic activation of these pathways leads to worsening cardiac function. The symptoms of heart failure can be associated with other conditions and include dyspnoea, fatigue, limitations in exercise tolerance and fluid accumulation, which can make diagnosis difficult. Management strategies include the use of pharmacological therapies and implantable devices to regulate cardiac function. Despite these available treatments, heart failure remains incurable, and patients have a poor prognosis and high mortality rate. Consequently, the development of new therapies is imperative and requires further research.

B-type natriuretic peptide increases cortisol and catecholamine concentrations in healthy subjects

B-type natriuretic peptide (BNP) is a hormone released by the heart in response to volume load and exerts natriuretic properties. It is clinically used as a diagnostic and prognostic biomarker and investigated as a pharmacological agent in the therapy of heart failure. Here we investigate the changes in pituitary, adrenal, and thyroid hormones in response to BNP administration in a randomized single-blinded crossover study conducted in ten healthy men aged 21–29 yr. Participants received in two study sessions a continuous intravenous infusion during 4 h (once placebo and once 3 pmol·kg−1·min−1 BNP) and remained in supine position throughout the study. Circulating concentrations of pituitary, adrenal, and thyroid hormones, heart rate, and blood pressure were measured at baseline and hourly afterwards. BNP prevented the physiological decrease in cortisol during the late morning hours leading to elevated serum cortisol levels ( P = 0.022) and increased circulating epinephrine and norepinephrine concentrations ( P = 0.018 and P = 0.036, respectively). These hormone changes were accompanied by an increase in heart rate ( P = 0.019) but no differences in blood pressure. Taken together, the impact of BNP on the endocrine system extends beyond the well-known inhibition of the renin-angiotensin-aldosterone system and includes increased adrenergic activity and cortisol concentrations. This neuroendocrine activation might impact the outcome of therapeutical BNP administrations and should be further investigated in conditions associated with increased BNP secretion.

NEW & NOTEWORTHY The heart hormone B-type natriuretic peptide (BNP) is increased in patients with heart failure, where it is thought to have beneficial effects by reducing the preload. Here we report that intravenous administration of BNP in men leads to increases in adrenal hormones cortisol, epinephrine, and norepinephrine. Cortisol and catecholamine levels are independent predictors of increased cardiovascular mortality risk; therefore, drugs targeting the BNP system should be evaluated regarding their effects on the neuroendocrine activation accompanying heart failure.

Resetting the neurohormonal balance in heart failure (HF): the relevance of the natriuretic peptide (NP) system to the clinical management of patients with HF

The natriuretic peptide (NP) system, which includes atrial natriuretic peptide, B-type natriuretic peptide, and C-type natriuretic peptide, has an important role in cardiovascular homeostasis, promoting a number of physiological effects including diuresis, vasodilation, and inhibition of the renin-angiotensin-aldosterone system. Heart failure (HF) is associated with defects in NP processing and synthesis, and there is a strong relationship between NP levels and disease state. NPs are useful biomarkers in HF, and their use in diagnosis and evaluation of prognosis is well established, particularly in patients with HF with reduced ejection fraction (HFrEF). There has also been interest in their use to guide disease management and therapeutic decision making. An understanding of NPs in HF has also resulted in interest in synthetic NPs for the treatment of HF and in treatments that target neprilysin, a protease that degrades NPs. A novel drug, the angiotensin receptor neprilysin inhibitor sacubitril/valsartan (LCZ696), which simultaneously inhibits neprilysin and blocks the angiotensin II type I receptor, was shown to have a favorable efficacy and safety profile in patients with HFrEF and has been approved for use in such patients in Europe and the USA. In light of the development of treatments that target neprilysin and of recent data in relation to synthetic NPs, it is timely to review the current understanding of the role of NPs in HF and their use in diagnosis, evaluating prognosis and guiding treatment, as well as their place in HF therapy.

Spotlight on valsartan-sacubitril fixed-dose combination for heart failure: the evidence to date

Heart failure is a global problem with elevated prevalence, and it is associated with substantial cardiovascular morbidity and mortality. Treating heart-failure patients has been a very challenging task. This review highlights the main pharmacological developments in the field of heart failure with reduced ejection fraction, giving emphasis to a drug that has a dual-acting inhibition of the neprilysin and renin–angiotensin–aldosterone system. Neprilysin is an enzyme that participates in the breakdown of biologically active natriuretic peptides and several other vasoactive compounds. The inhibition of neprilysin has been a therapeutic target for several drugs tested in cardiovascular disease, mainly for heart failure and/or hypertension. However, side effects and a lack of efficacy led to discontinuation of their development. LCZ696 is a first-in-class neprilysin- and angiotensin-receptor inhibitor that has been developed for use in heart failure. This drug is composed of two molecular moieties in a single crystalline complex: a neprilysin-inhibitor prodrug (sacubitril) and the angiotensin-receptor blocker (valsartan). The PARADIGM-HF trial demonstrated that this drug was superior to an angiotensin-converting enzyme inhibitor (enalapril) in reducing mortality in patients with heart failure with reduced ejection fraction. The ability to block the angiotensin receptor and augment the endogenous natriuretic peptide system provides a distinctive mechanism of action in cardiovascular disease.

The search for efficient diagnostic and prognostic biomarkers of heart failure

Several biomarkers have been tested for screening, diagnosis and prognosis purposes, as well as to guide treatment in heart failure, but only the assay of circulating B-type natriuretic peptides has widely recognized applications for clinical decision-making. Natriuretic peptides are sensitive in detecting the clinically overt or subclinical myocardial damage, but their plasma levels are increased following every generic insult to the cardiovascular system. Novel biomarkers are required to identify specific pathways of disease progression, such as diverse neurohormonal axes activation, inflammation and fibrogenesis, and to act as a tool for therapeutic tailoring. In this view, Gal-3 and ST-2 assays seem very promising, given their involvement in mechanisms of cardiac fibrosis and their prognostic value.

Biomarkers of Heart Failure with Preserved and Reduced Ejection Fraction

Biomarkers are increaingly being used in the management of heart failure not only for the purpose of screening, diagnosis, and risk stratification, but also as a guide to evaluate the response to treatment in the individual patient and as an entry criterion and/or a surrogate marker of efficacy in clinical trials testing novel drugs. In this chapter, we review the role of established biomarkers for heart failure management, according to the main classification of HF phenotypes, based on the measurement of left ventricular ejection fraction, including heart failure with reduced (<40%), preserved (≥50%), and, as recently proposed, mid-range (40-49%) ejection fraction.

Diagnostic utility of BNP, corin and furin as biomarkers for cardiovascular complications in type 2 diabetes mellitus patients

CONTEXT

The number of patients with type 2 diabetes mellitus (T2DM) is progressively increasing, and diabetic cardiovascular complications have become a public health problem. Brain or B-type natriuretic peptide (BNP) is a cardiac hormone synthesized as a pre-pro-peptide. pro-BNP is produced by cleaving the signal peptide then two proprotein convertases, corin and furin cleave pro-BNP to form a biologically active hormone. Two corin single nucleotide polymorphisms (SNPs) have been reported to alter corin protein conformation and impair its biological activity.

OBJECTIVE

We aimed to investigate the potential role of corin and furin in comparison to BNP as biomarkers for predicting cardiovascular complications in T2DM patients. The association of corin gene SNPs with corin levels was also examined.

METHODS

Seventy-five subjects were recruited in this study, including 25 T2DM patients with complications, 25 T2DM patients without complications as well as 25 healthy subjects. Plasma BNP, corin and furin levels were measured using enzyme-linked immunosorbent assays. Two corin SNPs were genotyped using allele specific oligonucleotide-polymerase chain reaction.

RESULTS

Both furin and BNP were found to be more sensitive than corin (80% versus 56%, p = 0.008), whereas furin showed higher specificity when compared to BNP (96% versus 84%, p = 0.041) and corin (96% versus 64%, p < 0.0001) in predicting cardiovascular complications in T2DM patients. Corin SNPs are not associated with corin levels, neither in the entire study cohort nor in the subgroup of T2DM patients with cardiovascular complications (p > 0.05).

CONCLUSIONS

Furin may be useful, either alone or in combination with other biomarkers, for cardiovascular risk stratification assessment in T2DM patients.

Insulin resistance is associated with increased concentrations of NT-proBNP in rheumatoid arthritis: IL-6 as a potential mediator

We examined the hypothesis that insulin resistance (IR) decreases circulating concentrations of N-terminal (NT)-probrain natriuretic peptide (BNP). Obesity, despite being a risk factor for heart failure (HF), is paradoxically associated with lower concentrations of BNP, a marker of myocardial stress. Low BNP in obesity is postulated to be due to IR; however, it has been difficult to define the role of IR independent of obesity. IR in rheumatoid arthritis (RA) is increased, independent of obesity, thus allowing potential mechanistic insights into the relationship between IR and BNP. We measured demographic factors, traditional cardiovascular risk factors, body mass index (BMI), markers of inflammation (interleukin-6 (IL-6), C-reactive protein (CRP), tumor necrosis factor α (TNFα)), NT-proBNP, and IR by the homeostatic model assessment (HOMA) in 140 patients with RA and 82 control subjects. Patients with heart failure and coronary artery disease were excluded. We used multiple linear regression models to examine the relationship between HOMA and NT-proBNP in RA and controls and in RA alone, the additional effect of inflammation. As previously reported, NT-proBNP concentrations were higher in RA (median 80.49 pg/mL, IQR (23.67-167.08 pg/mL)) than controls (17.84 pg/mL (3.28-36.28 pg/mL)) (P < 0.001), and the prevalence of IR, defined by HOMA > 2.114, was higher among RA than controls (53 % vs. 15%, P > 0.001). HOMA was positively correlated with NT-proBNP (rho = 0.226, P = 0.007) in RA, but not in controls (rho = -0.154, P = 0.168). In a multivariable model adjusted for age, race, and sex, we found that increasing HOMA was statistically associated with increasing NT-proBNP concentrations in RA (P = 0.001), but not controls (P = 0.543) (P for interaction = 0.036). In RA subjects, when IL-6 was further included in the model, IL-6 (P = 0.0014), but not HOMA (P = 0.43), remained significantly associated with NT-proBNP, suggesting that IL-6 may be mechanistically involved in the relationship between IR and NT-proBNP in RA. We conclude that in patients with RA, insulin resistance is associated with higher, rather than the expected lower, concentrations of NT-proBNP and that this may be related to increased IL-6.

Plasma amino-terminal pro B-type natriuretic peptide as a predictor of late cardiovascular mortality in patients with acute lung disorders: a prospective, observational cohort study

Aims

Pneumonia and acute exacerbations of obstructive lung diseases (AEOLD) are associated with a significant long‐term mortality. Elevated level of amino‐terminal pro B‐type natriuretic peptide (NT‐proBNP) is a predictor of late all‐cause mortality in these disorders but the pathophysiological basis for this is unknown. The present study was conducted to define the predictive role of NT‐proBNP on late cardiovascular mortality among patients with acute lung disorders.

Methods and results

This prospective, observational cohort study included 269 hospitalized patients with pneumonia or AEOLD. Plasma level of NT‐proBNP, age, sex, body mass index, arterial blood oxygen saturation, C‐reactive protein, and urea were recorded. The survival and causes of death were recorded after a median of six years. NT‐proBNP > 666 ng/mL was related to cardiovascular mortality with an adjusted hazard ratio of 2.93 (1.19–7.18). This risk was of similar magnitude to that associated with diabetes and greater than that associated with arterial hypertension, hypercholesterolemia, and smoking. NT‐proBNP was also related to all‐cause mortality with adjusted hazard ratio of 2.39 (1.49–3.85) per 10 times increase in NT‐proBNP concentration. However, the association between NT‐proBNP and non‐cardiovascular mortality did not reach statistical significance [adjusted hazard ratio 1.89 (0.93–3.85)].

Conclusion

NT‐proBNP concentration during pneumonia or AEOLD was strongly associated with late cardiovascular mortality but not with non‐cardiovascular mortality. The results suggest that the increase in NT‐proBNP during acute lung disorders may reveal occult cardiac diseases arousing a question whether patients with acute pulmonary disorders with elevated NT‐proBNP levels should be subjected to further diagnostic or therapeutic cardiovascular interventions.

Predictors of natriuretic peptide non-response in patients hospitalized with acute heart failure

Increasing natriuretic peptide (NP) levels are associated with worse heart failure (HF) outcomes. Predictors of NP nonresponse have not been studied. The aim of this study was to identify predictors of nondecreasing NP levels during episodes of acute HF. A retrospective analysis was conducted in patients prospectively included in a registry of acute HF, with the primary diagnosis of acute HF. The objective under analysis was B-type NP (BNP) response, defined as a >30% decrease in BNP during hospitalization. Percentage of BNP variation was calculated as: % BNP variation = [(admission BNP - discharge BNP)/admission BNP] × 100. A logistic regression analysis was performed to study potential predictors of NP nonresponse. A multivariate model was built. A total of 496 patients were studied: 28.2% were considered nonresponders to the implemented HF treatment strategy. Identified predictors of nonresponse were older age, chronic HF, lower admission systolic blood pressure, anemia, renal dysfunction, and lower sodium on admission, as well as lower admission albumin and lower admission total cholesterol. Admission BNP was not a predictor of response. The only identified independent predictor of nonresponse was a low admission total cholesterol level (cutoff 125 mg/dl), with an odds ratio of 2.55 (95% confidence interval 1.59 to 4.11). This remained valid when the analysis was stratified according to admission BNP (cutoff 2,000 pg/ml) and according to statin use. In conclusion, a low admission total cholesterol level was a strong and independent predictor of BNP nonresponse in patients admitted with acute HF. The ability of cholesterol to predict BNP nonresponse was valid for patients with intrinsically low cholesterol and in those with statin-induced low cholesterol.

Atrial natriuretic peptide gene variants and circulating levels: implications in cardiovascular diseases

ANP (atrial natriuretic peptide), discovered 30 years ago in rat cardiac atria, has been extensively investigated with regard to physiology, pathophysiology, cardiovascular disease therapeutics and molecular genetic aspects. Besides its diuretic, natriuretic and vasorelaxant effects, novel properties of this hormone have been described. Thus anti-hypertrophic, anti-fibrotic, anti-proliferative and anti-inflammatory actions suggest that ANP contributes not only to haemodynamic homoeostasis and adjustments, but has also a role in cardiovascular remodelling. Circulating ANP levels represent a valuable biomarker in cardiovascular diseases. ANP structure is highly conserved among species, indicating a key role in cardiovascular health. Thus an abnormal ANP structure may contribute to an increased risk of disease due to altered functions at either the vascular or cardiac level. Among others, the 2238T>C exon 3 variant has been associated with endothelial cell damage and dysfunction and with an increased risk of acute cardiovascular events, a frameshift mutation within exon 3 has been related to increased risk of atrial fibrillation, and ANP gene variants have been linked to increased risk of hypertension in different ethnic groups. On the other hand, the rs5068 variant, falling within the 3' UTR and associated with higher circulating ANP levels, has been shown to have a beneficial cardioprotective and metabolic effect. Dissecting out the disease mechanisms dependent on specific ANP molecular variants may reveal information useful in the clinical setting for diagnostic, prognostic and therapeutic purposes. Furthermore, insights from molecular genetic analysis of ANP may well integrate advancing knowledge on the role of ANP as a significant biomarker in patients affected by cardiovascular diseases.

Brain natriuretic peptide is a potent vasodilator in aged human microcirculation and shows a blunted response in heart failure patients

BACKGROUND

Brain natriuretic peptide (BNP) is normally present in low levels in the circulation, but it is elevated in parallel with the degree of congestion in heart failure subjects (CHF). BNP has natriuretic effects and is a potent vasodilator. It is suggested that BNP could be a therapeutic alternative in CHF. However, we postulated that the high levels of circulating BNP in CHF may downregulate the response of microvascular natriuretic receptors. This was tested by comparing 15 CHF patients (BNP > 3000 ng/L) with 10 matched, healthy controls.

METHODS

Cutaneous microvascular blood flow in the forearm was measured by laser Doppler Flowmetry. Local heating (+44°C, 10 min) was used to evoke a maximum local dilator response.

RESULTS

Non-invasive iontophoretic administration of either BNP or acetylcholine (ACh), a known endothelium-dependent dilator, elicited an increase in local flow. The nitric oxide synthase inhibitor, l-N-Arginine- methyl-ester (L-NAME), blocked the BNP response (in controls). Interestingly, responses to BNP in CHF patients were reduced to about one third of those seen in healthy controls (increase in flow: 251% in CHF vs. 908% in controls; P < 0.001). In contrast, the vasodilator responses to ACh and to local heating were only somewhat attenuated in CHF patients. Thus, dilator capacity and nitric oxide signalling were not affected to the same extent as BNP-mediated dilation, indicating a specific downregulation of the latter response.

CONCLUSIONS

The findings show for the first time that microvascular responses to BNP are markedly reduced in CHF patients. This is consistent with the hypothesis of BNP receptor function is downregulated in CHF.

Natriuretic peptides in cardiovascular diseases: current use and perspectives

The natriuretic peptides (NPs) family, including atrial, B-type, and C-type NPs, is a group of hormones possessing relevant haemodynamic and anti-remodelling actions in the cardiovascular (CV) system. Due to their diuretic, natriuretic, vasorelaxant, anti-proliferative, and anti-hypertrophic effects, they are involved in the pathogenic mechanisms leading to major CV diseases, such as heart failure (HF), coronary artery disease, hypertension and left ventricular hypertrophy, and cerebrovascular accidents. Blood levels of NPs have established predictive value in the diagnosis of HF, as well as for its prognostic stratification. In addition, they provide useful clinical information in hypertension and in both stable and unstable coronary artery disease. Structural abnormalities of atrial natriuretic peptide gene (NPPA), as well as genetically induced changes in circulating levels of NPs, have a pathogenic causal link with CV diseases and represent emerging markers of CV risk. Novel NP-based therapeutic strategies are currently under advanced clinical development, as they are expected to contribute to the future management of hypertension and HF. The present review provides a current appraisal of NPs' clinical implications and a critical perspective of the potential therapeutic impact of pharmacological manipulation of this class of CV hormones.

Management of chronic heart failure: biomarkers, monitors, and disease management programs

BACKGROUND

The management of patients with heart failure has been evolving given the complex nature of the disease and the increasing number of patients.

FINDINGS

Biomarkers, and in particular the natriuretic peptides, have been studied to assist with diagnosis, chronic management, and prognosis in patients with heart failure. Several new biomarkers are emerging and may be used individually or in combination with the natriuretic peptides. The use of cardiac monitoring devices and disease management programs is being established to assist in the care of patients with chronic heart failure. Interventions using phone calls, telemedicine devices, intracardiac pressure monitors, and implantable cardioverter defibrillators have been investigated.

CONCLUSIONS

The combination of biomarkers, monitoring devices, and disease management programs shows promise for improving care in this challenging patient population.

Ultrasensitive and ultrawide range detection of a cardiac biomarker on a surface plasmon resonance platform

One of the main challenges in the development of new analytical platforms for ultrasensitive bioaffinity detection is jointly achieving a wide dynamic range in target analyte concentration, especially for approaches that rely on multistep processes as a part of the signal amplification mechanism. In this paper, a new surface-based sandwich assay is introduced for the direct detection of B-type natriuretic peptide (BNP), an important biomarker for cardiac failure, at concentrations ranging from 1 aM to 500 nM. This was achieved using nanoparticle-enhanced surface plasmon resonance (SPR) where a DNA aptamer is immobilized on a chemically modified gold surface in conjunction with the specific adsorption of antiBNP coated gold nanocubes in the presence of the biomarker target. A concentration detection range greater than eleven orders of magnitude was achieved through dynamic control of only the secondary nanoparticle probe concentration. Furthermore, detection at low attomolar concentrations was also achieved in undiluted human serum.

The need for multicentre cardiovascular clinical trials in Asia

Historically, the USA and European countries have been the dominant figures in medical research. However, in the past 10 years, Asia has emerged as a new 'hot spot' for clinical research owing to the tremendous potential generated by steady economic growth, remarkable advances in research and development capacity, and an expanding population. However, investigators involved with the set-up and conduct of multicentre trials in such a vast and heterogeneous continent face huge challenges-bridging the fundamental differences between the Asian countries, such as languages, resources, regulatory procedural timelines, and the general understanding of clinical research. In this Perspectives article, we explain why Asia should be established as a hub for large multicentre trials, discuss the challenges involved, and highlight the importance of a strong collaborative infrastructure for multiple investigational sites in this culturally diverse continent.