Brain natriuretic peptide: Much more than a biomarker

The utility of brain natriuretic peptide as a prognosticating marker in critical care patients

Background

Brain natriuretic peptide (BNP) is an established biomarker of morbidity and mortality in cardiac failure. Data also suggest potential prognostic utility in non-heart failure cohorts. The utility of BNP in predicting intensive care unit (ICU) outcomes has not been well evaluated in a mixed critical care population in the South African (SA) context.

Objectives

To evaluate the ability of BNP to predict ICU mortality in a heterogeneous critical care population in SA.

Methods

This was a retrospective observational study of 100 patients admitted to a multidisciplinary, closed, intensivist-run ICU in a tertiary academic hospital serving KwaZulu-Natal Province (1 January 2020 - 31 July 2022). Initial BNP was evaluated as a predictor of ICU mortality using univariate and multivariable analyses.

Results

There was a statistically significant difference in BNP between survivors and non-survivors in the cohort of patients without heart failure. The median initial BNP in the non-heart failure cohort was 411 (interquartile range (IQR) 116 - 848) ng/L in non-survivors, and 150 (44 - 356) ng/L in survivors (p=0.028). The optimal cut-off for BNP was determined as 366 ng/L. A BNP ≥366 ng/L was an independent predictor of ICU outcome.

Conclusion

This study highlights the potential utility of BNP as a predictor of ICU mortality in a heterogeneous ICU population, with the greatest utility in patients without heart failure. Further studies are required to confirm this finding.

Contribution of the study

The study is a retrospective, observational study conducted in multidisciplinary, closed, intensivist-run ICU at a tertiary academic hospital. It showed an elevated BNP is associated with increased ICU mortality, particularly in those without a baseline diagnosis of heart failure. This identifies the need for further prospective studies evaluating BNP as a prognostic marker in non-cardiac critically ill patients, and its utility as an addition in pre-existing ICU outcome prediction scores.

NT-proBNP in Different Patient Groups of COPD: A Systematic Review and Meta-Analysis

Purpose

NT-proBNP, a peptide biomarker synthesized and secreted by cardiomyocytes in response to cardiac load, has gained attention in recent years for its potential role in respiratory diseases. Chronic Obstructive Pulmonary Disease (COPD), a chronic and progressive inflammatory condition affecting the respiratory system, is frequently associated with comorbidities involving the cardiovascular system. Consequently, the aim of this systematic review and meta-analysis was to evaluate the variations in NT-proBNP levels across distinct patient groups with COPD and establish a foundation for future investigations into the precise clinical significance of NT-proBNP in COPD.

Methods

The search databases for this study were conducted in PubMed, Excerpt Medica database (Embase), Web of Science (WOS), and Cochrane Library databases. Databases were searched for studies on the predictive value of NT-proBNP in adult COPD patients.

Results

A total of 29 studies (8534 participants) were included. Patients with stable COPD exhibit elevated levels of NT-proBNP [standardized mean difference(SMD) [95CI%]=0.51 [0.13,0.89]; p=0.0092]. COPD patients with predicted forced expiratory volume in 1 s (FEV₁) < 50% exhibit significantly elevated levels of NT-proBNP compared to those with FEV₁ ⩾50%[SMD [95CI%]=0.17 [0.05,0.29]; p=0.0058]. NT-proBNP levels were significantly higher in acute exacerbations (AECOPD) compared to patients with stable COPD [SMD [95CI%]=1.18 [0.07,2.29]; p=0.037]. NT-proBNP levels was significantly higher in non-survivors than in survivors of hospitalised AECOPD patients [SMD [95CI%]=1.67 [0.47,2.88]; p=0.0063]. Both COPD patients with pulmonary hypertension(PH) [SMD [95CI%]=0.82 [0.69,0.96]; p<0.0001] and chronic heart failure(CHF) [SMD [95CI%]=1.49 [0.96,2.01]; p<0.0001] showed higher NT-proBNP level.

Conclusion

NT-proBNP, a biomarker commonly used in clinical practice to evaluate cardiovascular disease, demonstrates significant variations in different stages of COPD and during the progression of the disease. The fluctuations in NT-proBNP levels could be indicative of the severity of pulmonary hypoxia and inflammation and cardiovascular stress among COPD patients. Therefore, assessing NT-proBNP levels in COPD patients can aid in making informed clinical decisions.

VDR Regulates BNP Promoting Neurite Growth and Survival of Cochlear Spiral Ganglion Neurons through cGMP-PKG Signaling Pathway

Spiral ganglion neurons (SGNs) are important for hearing, and their peripheral and central processes connect sensory cells of the Corti organ to the central nervous system. The resulting network forms a point-to-point auditory conduction. As a cardiac hormone, brain natriuretic peptide (BNP) binds to natriuretic peptide receptor type A leading to diuresis, vasodilatation, inhibition of renin and aldosterone production, and cardiac and vascular myocyte growth. This study primarily aimed to explore the expression and function of BNP in the rat's inner ear and elucidate its regulatory mechanism. We determined the expression and function of BNP and found that the vitamin D receptor (VDR) could upregulate the expression of BNP and enhance its function. In SGNs of the rat inner ear, BNP promotes neuron survival and prolongs neurite length through the cGMP-PKG signaling pathway, which could be regulated by VDR and provide a novel approach for neuronal regeneration therapy. To the best of our knowledge, this is the first study to report this potential transcriptional regulatory relationship and will act as a reference for research on neuronal regeneration therapy for SGNs injury.

Clinical applications of plasma proteomics and peptidomics: Towards precision medicine

In the context of precision medicine, disease treatment requires individualized strategies based on the underlying molecular characteristics to overcome therapeutic challenges posed by heterogeneity. For this purpose, it is essential to develop new biomarkers to diagnose, stratify, or possibly prevent diseases. Plasma is an available source of biomarkers that greatly reflects the physiological and pathological conditions of the body. An increasing number of studies are focusing on proteins and peptides, including many involving the Human Proteome Project (HPP) of the Human Proteome Organization (HUPO), and proteomics and peptidomics techniques are emerging as critical tools for developing novel precision medicine preventative measures. Excitingly, the emerging plasma proteomics and peptidomics toolbox exhibits a huge potential for studying pathogenesis of diseases (e.g., COVID-19 and cancer), identifying valuable biomarkers and improving clinical management. However, the enormous complexity and wide dynamic range of plasma proteins makes plasma proteome profiling challenging. Herein, we summarize the recent advances in plasma proteomics and peptidomics with a focus on their emerging roles in COVID-19 and cancer research, aiming to emphasize the significance of plasma proteomics and peptidomics in clinical applications and precision medicine.

MiRNAs and circRNAs for the Diagnosis of Anthracycline-Induced Cardiotoxicity in Breast Cancer Patients: A Narrative Review

Breast cancer (BC) is the most frequent type of female cancer with increasing incidence in recent years. Doxorubicin (DOX) is an important backbone chemotherapy in BC, responsible for cardiotoxicity (CTX) in about 9% of treated women within the first year. Biomarkers of early CTX diagnosis are essential to avoid complicated DOX-related cardiac diseases. Traditional serum biomarkers are either poorly sensitive with transient elevation, and even absent if investigated outside their diagnostic window, or arise only in late-stage CTX. Emerging biomarkers such as non-coding RNA (ncRNA) have been recently investigated in DOX-related CTX. In our review, we revised the role of microRNAs, the most studied type of ncRNA, both in animal and human models, highlighting the interesting but often contrasting results. Moreover, we reviewed a novel class of ncRNA, circular RNA (circRNA), focusing on their modulatory mechanisms also involving microRNAs. MicroRNA and circRNA are players in a wide homeostatic balance with their perturbation representing a possible compensation for DOX damage. Further studies are required to assess the modalities of early detection of their variation in BC patients suffering from heart disease induced by DOX treatment.

A predictive model for dilated cardiomyopathy with pulmonary hypertension

Aims

Dilated cardiomyopathy (DCM) is defined as a serious cardiac disorder caused by the presence of left ventricular dilatation and contractile dysfunction in the absence of severe coronary artery disease and abnormal loading conditions. The incidence of cardiac death is markedly higher in patients with DCM with pulmonary hypertension (PH) than in DCM patients without PH. No previous studies have constructed a predictive model to predict PH in patients with DCM.

Methods

Data from 218 DCM patients (68.3% man; mean age 57.33) were collected. Patients were divided into low, intermediate and high PH‐risk groups based on the echocardiographic assessment at the tricuspid regurgitation peak velocity (TRV) in conjunction with the presence of echocardiographic signs from at least two different categories. Basic information, vital signs, comorbidities and biochemical data of each patient were determined. The impact of each parameter on PH probability was analysed by univariable and multivariable analyses, the data from which were employed to establish a predictive model. Finally, the discriminability, calibration ability and clinical efficacy of the model were verified for both the modelling group and the external validation group.

Results

We successfully applied a history of chronic obstructive pulmonary disease (COPD) or chronic bronchitis, systolic murmur (SM) at the tricuspid area, SM at the apex and brain natriuretic peptide (BNP) level to establish a model for predicting PH probability in DCM. The model was proven to have high accuracy and good discriminability (area under the receiver operating characteristic curve 0.889), calibration ability and clinical application value.

Conclusions

A model for predicting PH probability in patients with DCM was successfully established. The new model is reliable for predicting PH probability in DCM and has good clinical applicability.

Room-temperature controllable synthesis of hierarchically flower-like hollow covalent organic frameworks for brain natriuretic peptide enrichment

A facile strategy was introduced for room-temperature controllable synthesis of hierarchically flower-like hollow COFs (FHF-COFs). Furthermore, the universality for synthesis of the HFH-COFs was validated by altering the building units. Inspired by the unique morphology, extremely large surface area and good chemical stability, HFH-COFs could serve as an attractive adsorption probe by loading with gold nanoparticles and be applied to enrichment of brain natriuretic peptide from human serum. This work opens up a whole new approach for controllable synthesis of the HFH-COFs at room temperature and expands the application of COFs as a promising enrichment probe for complex biological samples.

NT-proBNP in young healthy adults undergoing non-cardiac surgery

OBJECTIVES

N-terminal pro-brain natriuretic peptide (NT-proBNP), a standard marker for diagnosis and treatment guidance of heart failure, has previously been investigated in high-risk patients undergoing cardiac and non-cardiac surgery. However, the kinetics of NT-proBNP in healthy patients undergoing non-cardiac surgery are unknown.

DESIGN & METHODS

A secondary analysis of a prospective cohort study was conducted. NT-proBNP plasma concentrations were measured preoperatively, 2-6 h, and 18-30 h after surgery in 120 patients, 18-35 years, undergoing elective non-cardiac surgery. Reasons for non-inclusion: history or symptoms of cardiac disease, kidney disease, pulmonary embolism, thrombosis, stroke, diabetes, head or chest trauma, pregnancy, incomplete panel of perioperative NT-proBNP plasma samples. Absolute and relative change of NT-proBNP plasma concentration were calculated. Changes between preoperative, 2-6 h, and 18-30 h (POD 1) NT-proBNP values, and of within-patient change in NT-proBNP were analyzed.

RESULTS

In 95 patients, NT-proBNP plasma concentrations (median [IQR]) were 8 [5-26] pg/mL at baseline, 17 [5-53] pg/mL 2-6 h, and 42 [11-86] pg/mL 18-30 h after surgery. Absolute and relative NT-proBNP increase after surgery was 32 [5-74] pg/mL and 196% [61 - 592%] compared to baseline. NT-proBNP elevation above the age- and sex-specific reference range was observed in 6/95 (6%) patients prior to surgery and in 39/95 (41%) patients after surgery.

CONCLUSIONS

Even after uncomplicated surgery and postoperative period, NT-proBNP concentrations markedly increase in otherwise healthy adult patients. The aetiology of postoperative NT-proBNP increase is currently unknown and may be multifactorial.

Expression of miR-93-5p as a Potential Predictor of the Severity of Chronic Thromboembolic Pulmonary Hypertension

Background

MicroRNAs (miRNAs) play an important role in the pathogenesis of chronic thromboembolic pulmonary hypertension (CTEPH). However, the potential correlation between miRNA expression and the severity of CTEPH remains unclear. Our previous study indicated that miRNAs hsa-let-7b-3p, hsa-miR-17-5p, hsa-miR-106b-5p, hsa-miR-3202, hsa-miR-665, and hsa-miR-93-5p are closely involved in CTEPH. This study assessed the associations between the expression levels of these miRNAs and clinical parameters in CTEPH patients.

Methods

A total of eight CTEPH patients and eight healthy adults as a reference group were included, and clinical data including total protein (TP), albumin (Alb), lactate dehydrogenase (LDH), hydroxybutyrate dehydrogenase (HBDH), uric acid (UA), and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were collected. Right heart catheterization was conducted to obtain hemodynamic data including cardiac index (CI). The expression levels of let-7b-3p, miR-17-5p, miR-106b-5p, miR-3202, miR-665, and miR-93-5p were measured by quantitative real-time PCR (qPCR). Correlation analysis was applied to estimate the associations between miRNA expression levels and clinical parameters in CTEPH patients.

Results

Serum TP and Alb levels were decreased, while LDH, HBDH, and UA levels were increased in CTEPH patients compared with the reference group (P < 0.05). miR-3202 and miR-665 were upregulated, whereas let-7b-3p, miR-17-5p, miR-106b-5p, and miR-93-5p were downregulated in CTEPH patients relative to the reference group (P < 0.05). miR-93-5p expression was positively correlated with NT-proBNP level and negatively correlated with CI (P < 0.05). Moreover, let-7b-3p tended to be positively correlated with mean pulmonary arterial pressure.

Conclusions

miR-93-5p expression was associated with the severity of CTEPH and could act as a potential predictor of high-risk CTEPH.

Conventional vs high-sensitive troponins in acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Cardiac troponins (cTn), either conventional or high-sensitive (hscTn) assays, are often performed during acute exacerbations of chronic obstructive pulmonary disease (AECOPD).

OBJECTIVES

To compare factors affecting abnormal conventional cTn and hscTn.

METHODS

We retrospectively studied data from AECOPD patients with conventional or hscTn performed at presentation. Binary logistic regression was used to identify predictors for abnormal conventional cTn (>0.5 ug/L) and hscTn (>40 ng/L).

RESULTS

There were 466 patients in the conventional cTn and 313 patients in the hscTn groups. Ischaemic electrocardiographic change was the only significant predictor for abnormal conventional cTn (OR 6.662 [CI 1.233-35.990], p = 0.028) while B-type natriuretic peptide levels (Adj OR 1.004 [CI 1.000-1.006], p = 0.010) and SpO₂/FiO₂ ratio (Adj OR 0.115 [CI 0.017-0.069], p = 0.026) were significant predictors of abnormal hscTn.

CONCLUSIONS

Predictors of abnormal cTn differ between assays and should be taken into consideration when interpreting cTn during AECOPD.

Advances in understanding of mechanisms related to increased cardiovascular risk in COPD

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) represents a serious global health issue that is commonly associated with cardiovascular (CV) disease (CVD). The close relationship between COPD and CVD could be explained by different factors, first and foremost a chronic low-grade systemic inflammation implicated in the pathogenesis of both diseases and several stimuli enhancing the inflammatory processes and causing a mixed condition with worse outcomes than either disorder alone.

AREAS COVERED

The present narrative review considers the mechanisms underlying the increased CV risk in COPD, and it provides insights on biomarkers and predictive models to predict CVD in COPD patients.

EXPERT OPINION

COPD patients often remain asymptomatic of CVD, with respiratory symptoms generally attributed to the preexisting pulmonary disease. It is fundamental to understand the mechanistic pathways that underpin the intimate relationship between the two disorders. However, it is still not clear what is the origin of the common background of low-grade systemic inflammation, it could be a 'spillover' or a general inflammatory state. Primary prevention, cross-collaboration between specialists and early detection via predictive biomarkers and validated models are fundamental to stratify COPD patients according to CV risk.

How to use N-terminal pro-brain natriuretic peptide (NT-proBNP) in assessing disease severity in bronchiolitis

Bronchiolitis is a common viral illness which can lead to severe respiratory compromise and can coexist with or mask cardiac failure. Brain natriuretic peptide (BNP) and the inactive portion of its pro-hormone: N-terminal pro-BNP (NT-proBNP) are excreted in response to cardiomyocyte stretching and are established biomarkers in cardiac failure. Here, we discuss the technicalities of NT-proBNP testing and review available evidence regarding NT-proBNP testing in bronchiolitis. We identified and appraised seven studies assessing the role of BNP or NT-proBNP as biomarkers of bronchiolitis severity, in children with and without underlying congenital cardiac disease. One study of 76 children with dyspnoea showed that the median NT-proBNP level in children with cardiac failure was 7321 pg/mL vs 241 pg/mL in children with a respiratory cause of dyspnoea vs 87.21 pg/mL in healthy controls (p<0.05). A cut-off of 726 pg/mL could aid differentiation between cardiac and respiratory causes of respiratory distress. Other evidence showed a positive correlation between BNP levels and bronchiolitis severity, and that raised BNP can predict acute heart failure in children with congenital cardiac disease presenting with bronchiolitis. However, most studies consisted of small cohorts with conflicting evidence between them. Furthermore, several studies assessed BNP rather than NT-proBNP directly. BNP has a shorter half-life, which may affect analysis. In conclusion, NT-proBNP is a rapid and inexpensive test with the potential to be a useful biomarker in severe bronchiolitis and cases complicated by acute cardiac failure. However, studies with larger cohorts are required to better establish this role.

Vitamin B12 Supplementation and NT-proBNP Levels in COPD Patients: A Secondary Analysis of a Randomized and Controlled Study in Rehabilitation

Purpose

There is evidence of complex interaction between vitamin B₁₂ (vB₁₂) level, hyperhomocysteinemia (HyCy), and natriuretic peptide secretion. Exercise training could also modulate such interaction. In this secondary analysis of a Randomized Clinical Trial performed in a chronic obstructive pulmonary disease (COPD) rehabilitation setting, our primary objective was to investigate the interaction between vB₁₂ supplementation, exercise training, and changes in NT-proBNP levels after 8 weeks of intervention. Secondary objectives were to explore the correlations between acute changes in NT-proBNP levels with (i) acute exercise and (ii) oxygen uptake (V’O₂) kinetics during rest-to-exercise transition.

Methods

Thirty-two subjects with COPD were randomized into four groups: Rehabilitation+vB₁₂ (n = 8), Rehabilitation (n = 8), vB₁₂ (n = 8), or Maltodextrin(n = 8). They were evaluated at baseline and after 8 weeks, during resting and immediately after maximal exercise constant work-rate tests (CWTs, Tlim), for NT-proBNP plasmatic levels.

Results

After interaction analysis, the supplementation with vB₁₂ significantly changed the time course of NT-proBNP responses during treatment (p = 0.048). However, the final analysis could not support a significant change in NT-proBNP levels owing to high-intensity constant work-rate exercise (p-value > 0.05). There was a statistically significant correlation between V’O₂ time constant and ΔNT-proBNP values (Tlim – rest) at baseline (p = 0.049) and 2 months later (p = 0.015), considering all subjects (n = 32).

Conclusion

We conclude that vB₁₂ supplementation could modulate NT-proBNP secretion. Moreover, possibly, the slower the initial V’O₂ adjustments toward a steady-state during rest-to-exercise transitions, the more severe the ventricular chamber volume/pressure stress recruitment, expressed through higher NT-proBNP secretion in subjects with larger V’O₂ time constants, despite unchanged final acute exercise-induced neurohormone secretion.

Pre and postoperative risk management: the role of scores and biomarkers

PURPOSE OF REVIEW

The goal of risk prediction is to identify high-risk patients who will benefit from further preoperative evaluation. Clinical scores and biomarkers are very well established tools for risk prediction but their accuracy remains a controversial issue.

RECENT FINDINGS

Current guidelines recommend one of the risk tools for preoperative cardiac risk assessment: American College of Surgeons National Surgical Quality Improvement Program (NSQIP) calculator or Revised Cardiac Risk Index. Although not as easy to use as risk scores, risk models are more accurate and can predict individual patient risk more precisely. A step forward in risk estimation was performed by introducing new risk models developed from the American College of Surgeons NSQIP database - NSQIP surgical risk calculator and Myocardial Infarction or Cardiac Arrest index. Although biomarkers, especially in cardiac risk assessment, are already present in current European and American guidelines, this use is still controversial. Novel biomarkers: microRNAs, heart-type fatty acid-binding protein and mid-regional proadrenomedullin, can be used as new potential biomarkers in clinical practice. Also some of the experimental biomarkers have not yet been introduced into clinical practice, preliminary results are encouraging.

SUMMARY

Different risk indices and biomarkers might lead to varying risk estimates. However, the importance of clinical judgment in risk assessment should not be underestimated.

The Assessment of Myocardial Strain by Cardiac Imaging in Healthy Infants with Acute Bronchiolitis: A Systematic Review and Meta-Analysis

This study aims to systematically review the incidence of myocardial strain detected by echocardiography in previously healthy infants with acute bronchiolitis and its role as a predictor for adverse outcomes in this setting.

METHODS

Pubmed/Medline, Excerpta Medica Data Base (EMBASE), and Cochrane Library were searched in April 2020 to identify original observational prospective studies that systematically performed echocardiography for the screening of myocardial strain in healthy infants with acute bronchiolitis. Pooled estimates were generated using random-effects models. Heterogeneity within studies was assessed using Cochran's Q and I² statistics. Funnel plots and Egger´s regression method were constructed to evaluate publication bias. Sensitivity analyses were also conducted to evaluate potential sources of heterogeneity.

RESULTS

After a detailed screening of 305 articles, a total of 10 studies with 395 participants (mean of 40 participants per study) was included. Five of them were classified as high-quality studies. Up to 28% of cases presented adverse outcomes. The echocardiographic screening for myocardial strain was performed within the first 24 h of admission in 92% cases. Tissue Doppler imaging and Speckle-Tracking echocardiography were performed only in 20% of cases. The presence of pulmonary hypertension was evaluated with methods different from the tricuspid regurgitation jet in 64% of cases. Seven studies found some grade of myocardial strain with a pooled incidence of 21% (CI 95%, 11-31%), in the form of pulmonary hypertension (pooled incidence of 20% (CI 95%, 11-30%)), and myocardial dysfunction (pooled incidence of 5% (CI 95%, 1-9%)). The presence of these echocardiographic alterations was associated with adverse outcomes (pooled relative risk = 16; CI 95%, 8.2-31.5). After a subgroup analysis based on the echocardiographic techniques used, no significant heterogeneity across the studies was observed. There was no evidence of publication bias when assessed by Egger´s test. Cardiac biomarkers to assess myocardial strain were used in five studies. Only N-terminal-pro-brain natriuretic peptide accurately predicted the presence of myocardial strain by echocardiography.

CONCLUSIONS

Myocardial strain is not infrequent in previously healthy infants with acute bronchiolitis, and it could be present at the early stages of the disease with prognostic implications. There is a need for sufficiently powered prospective studies with a similar methodology, preferably employing advanced imaging techniques, to conclusively address the usefulness of the assessment of myocardial strain in this setting.

Cardiac Biomarkers in the Setting of Asthma Exacerbations: a Review of Clinical Implications and Practical Considerations

PURPOSE OF REVIEW

The present paper aims to highlight clinical implications of elevated cardiac biomarkers and associated myocardial dysfunction in a variety of cardiac and non-cardiac scenarios in patients with an asthma exacerbation, and to propose a basic algorithm for cardiovascular evaluation and triage (and hence, for further management) of these patients primarily based on evaluation of cardiac biomarkers along with basic diagnostic modalities and specific cardiac symptoms in the hospital setting.

RECENT FINDINGS

Elevation of cardiac biomarkers in the setting of an asthma exacerbation mostly signifies a new-onset subclinical myocardial dysfunction/injury generally associated with certain asthma-related factors including acute hypoxemia and bronchodilator therapy, and usually has a limited prognostic value in these patients. On the other hand, elevation of these biomarkers in patients with an asthma exacerbation might also denote a variety of certain life-threatening cardiac or non-cardiac conditions associated with significant myocardial dysfunction (acute coronary syndromes (ACSs), sepsis, etc.) that might be masked by the rampant course of the asthma exacerbation, and hence, might possibly go undetected potentially aggravating the prognosis in a portion of these patients. In patients with an asthma exacerbation, it seems imperative to timely diagnose and manage emerging diverse clinical conditions particularly through the guidance of cardiac biomarkers and associated myocardial dysfunction patterns in an effort to improve overall prognosis in these patients.

Increasing Age Hinders the Decline in B-Type Natriuretic Peptide Following Parathyroidectomy in Dialysis Patients

BACKGROUND/AIM

Parathyroidectomy has beneficial effects on all-cause and cardiovascular mortality in patients with uncontrolled hyperparathyroidism. B-Type natriuretic peptide (BNP) correlates with the severity of heart failure. We aimed to investigate whether parathyroidectomy modulates the BNP levels in dialysis patients.

PATIENTS AND METHODS

Patients who underwent surgical intervention for hyperparathyroidism were included. The serum BNP levels were determined before parathyroidectomy and during follow-up.

RESULTS

The preoperative and postoperative BNP levels were 499±561 and 453±442 pg/ml, respectively (p=0.82). The baseline BNP level was positively correlated with weakness and headache, but not biochemical parameters. In multivariate analysis, age (odds ratio=0.837) and preoperative symptom score (odds ratio=0.935) were independent predictors for the postoperative decline in BNP levels Conclusion: The serum BNP levels may increase or decrease after parathyroidectomy. Younger age and lower symptom burden are associated with decline in BNP levels.

NT-proBNP plasma levels as biomarkers for pulmonary hypertension in healthy infants with respiratory syncytial virus infection

Aim: To explore NT-proBNP as biomarker for pulmonary hypertension (PH) in infants with respiratory syncytial virus infection (RSVI). Patients & methods: We prospectively enrolled 93 healthy infants with RSVI aged 1-12 months. NT-proBNP determination and echocardiography were performed at admission. Results: PH was found in 22% of patients and associated with a severe course of the disease. NT-proBNP >1635 pg/ml resulted an independent predictor for PH (odds ratio: 16.46 [95% CI: 4.10-66; p < 0.001]). The diagnostic performance of NT-proBNP to detect PH in RSVI was high (area under receiver operator curve of 0.932 [95% CI: 0.883-0.981; p < 0.001]). Conclusions: The presence of PH in healthy infants with RSVI is associated with worse outcomes. NT-proBNP resulted an accurate biomarker for PH in this setting.

Biomarkers in Aortic Valve Stenosis and their Clinical Significance in Transcatheter Aortic Valve Implantation

Aortic valve stenosis is one of the most common valvular heart disorders and the prevalence will rise as the population ages. Once symptomatic patients with aortic valve stenosis tend to fare worse with high mortality rates. Aortic valve replacement is indicated in these patients and besides the standard surgical replacement, a less invasive approach, transcatheter aortic valve implantation, has gained momentum and has showed promising and solid results in patients with high surgical risk. An important aspect of evaluating patients with aortic valve stenosis is the ability to choose the best possible candidate for the procedure. In addition, predicting the short and long-term clinical outcomes after the valve replacement could offer the treating physicians a better insight and provide information for optimal therapy. Biomarkers are biological parameters that can be objectively measured and evaluated as indicators of normal biological processes and are easily monitored. The aim of this review is to critically assess some of the most widely used biomarkers at present (natriuretic peptides, troponins, C-reactive protein) and provide an insight in novel biomarkers that are currently being investigated (galectin-3, growth differentiation factor-15, microRNAs) for possible diagnostic and prognostic use in aortic valve stenosis and transcatheter aortic valve implantation respectively.

Circular RNAs as potential biomarkers and therapeutics for cardiovascular disease

Circular RNAs (circRNAs) are genetic regulators that were earlier considered as "junk". In contrast to linear RNAs, they have covalently linked ends with no polyadenylated tails. CircRNAs can act as RNA-binding proteins, sequestering agents, transcriptional regulators, as well as microRNA sponges. In addition, it is reported that some selected circRNAs are transformed into functional proteins. These RNA molecules always circularize through covalent bonds, and their presence has been demonstrated across species. They are usually abundant and stable as well as evolutionarily conserved in tissues (liver, lung, stomach), saliva, exosomes, and blood. Therefore, they have been proposed as the "next big thing" in molecular biomarkers for several diseases, particularly in cancer. Recently, circRNAs have been investigated in cardiovascular diseases (CVD) and reported to play important roles in heart failure, coronary artery disease, and myocardial infarction. Here, we review the recent literature and discuss the impact and the diagnostic and prognostic values of circRNAs in CVD.

High-level production of N-terminal pro-brain natriuretic peptide, as a calibrant of heart failure diagnosis, in Escherichia coli

Heart failure (HF) is a coronary disease that affects people worldwide and has a high mortality rate. N-terminal pro-brain natriuretic peptide (NT-proBNP) has been proven to be a useful and accurate biomarker for diagnosing systolic HF. Here, we report a strategy for the high-level production of recombinant (r)NT-proBNP in Escherichia coli. An Fh8 tag with six histidines was fused to the N terminus of NT-proBNP along with the recognition site of tobacco etch virus (TEV) protease; the 6HFh8-NT-proBNP fusion peptide was expressed in flask cultures of E. coli in almost completely soluble form. The peptide was purified by HisTrap affinity chromatography, and the N-terminal tag was cleaved by TEV protease. After a second round of HisTrap affinity chromatography to remove the TEV protease and N-terminal tag, rNT-proBNP was isolated with high purity (≥ 98%) by carboxymethyl cation exchange chromatography. The final yield of purified rNT-proBNP (97.5 mg/l of bacterial culture; 3.25 mg/g of wet cell) was 55-fold higher than that reported in previous studies (0.5-1.75 mg/l of bacterial culture). Furthermore, the high cell density E. coli fed-batch culture enabled high-level production of rNT-proBNP in the order of grams per liter. The purified rNT-proBNP was detected by enzyme-linked immunosorbent assay and chemiluminescence enzyme immunoassay using commercial monoclonal antibodies recognizing different epitopes, showing a linear dose-response relationship in the range of tested concentrations (slope = 3.58 and r² = 0.995). These results demonstrate the efficiency of our process for mass producing (gram-to-liter level) rNT-proBNP with acceptable analytical performance.

Role of microRNAs in doxorubicin-induced cardiotoxicity: an overview of preclinical models and cancer patients

Cardiotoxicity is a well-known side effect of doxorubicin (DOX), but the mechanisms leading to this phenomenon are still not completely clear. Prediction of drug-induced dysfunction onset is difficult and is still largely based on detection of cardiac troponin (cTn), a circulating marker of heart damage. In the last years, several investigations focused on the possible involvement of microRNAs (miRNAs) in DOX-induced toxicity in vitro, with contrasting results. Recently, several groups employed animal models to mimic patient’s condition, investigate the biological pathways perturbed by DOX, and identify diagnostic markers of cardiotoxicity. We reviewed the results from several studies investigating cardiac miRNAs expression in rodent models of DOX-treatment. We also discussed the data from two publications indicating the possible use of circulating miRNA as biomarkers of DOX-induced cardiotoxicity. Unfortunately, limited information was derived from these studies, as selection methods of candidate-miRNAs and heterogeneity in cardiotoxicity assessment greatly hampered the novelty and robustness of the findings. Nevertheless, at least one circulating miRNA, miR-1, showed a good potential as early biomarker of drug-mediated cardiac dysfunction onset. The use of animal models to investigate DOX-induced cardiotoxicity surely helps narrowing the gap between basic research and clinical practice. Despite this, several issues, including selection of relevant miRNAs and less-than-optimal assessment of cardiotoxicity, greatly limited the results obtained so far. Nonetheless, the association of patients-based studies with the use of preclinical models may be the key to address the many unanswered questions regarding the pathophysiology and early detection of cardiotoxicity.

Metabolomic profiling implicates adiponectin as mediator of a favorable lipoprotein profile associated with NT-proBNP

Background

The N-terminal prohormone of brain natriuretic peptide (NT-proBNP) is an important biomarker for the diagnosis of heart failure. Apart from this and only recently recognized, NT-proBNP levels associate with higher HDL- and lower LDL-cholesterol levels comprising a favorable blood lipid profile. To further examine this observation, the lipoprotein profile in relation to NT-proBNP was examined in-depth by proton nuclear magnetic resonance spectroscopy (¹H-NMR). We complemented this investigation with a state-of-the-art untargeted metabolomics approach.

Methods

Lipoprotein particles were determined by ¹H-NMR spectroscopy in 872 subjects without self-reported diabetes from the population-based Study of Health in Pomerania (SHIP)-TREND with available NT-proBNP measurements. Comprehensive metabolomics data for plasma and urine samples were obtained. Linear regression models were performed to assess the associations between serum concentrations of NT-proBNP and the metabolites/lipoprotein particles measured in plasma or urine.

Results

An increase in serum NT-proBNP was associated with a benefical lipoprotein profile, including a decrease in VLDL, IDL and LDL-particles along with an increase in large HDL particles. These findings were replicated in a second independent cohort. Serum concentrations of NT-proBNP showed significant inverse associations with seven plasma metabolites while associations with 39 urinary metabolites, mostly comprising amino acids and related intermediates, were identified. Mediation analyses revealed adiponection as mediating factor for the associations observed with lipoproteins particles.

Conclusions

Most of the metabolic changes associated with NT-proBNP implicate significant influence on the blood lipid profile besides vasodilatory and the diuretic action of BNP signaling. Our data suggest that the more favorable lipoprotein profile as associated with elevated NT-proBNP concentrations in mainly cardiac healthy individuals might relate to adiponectin signaling indicating even indirect cardio-protective effects for NT-proBNP.

Electronic supplementary material

The online version of this article (10.1186/s12933-018-0765-1) contains supplementary material, which is available to authorized users.

[Atrial natriuretic hormones and metabolic syndrome: recent advances]

Natriuretic peptides are a group of hormones including atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), C type (CNP), urodilatin and guanilyn. ANP (half-life: 2-4 min), is secreted by the atrium, BNP (half-life: 20 min) by the ventricle, CNP by the vascular endothelium, urodilatin by the kidney and guanylin by the intestine. These natriuretic peptides prevent water and salt retention through renal action, vasodilatation and hormonal inhibition of aldosterone, vasopressin and cortisol. These peptides also have a recently demonstrated metabolic effect through an increase of lipolysis, thermogenesis, beta cell proliferation and muscular sensitivity to insulin. Blood levels of these natriuretic peptides depend on "active NPR-A receptors/clearance NPR-C receptors", the last ones being abundant on adipocytes. Therefore, natriuretic peptides act as adipose tissue regulator and constitute a link between blood pressure and metabolic syndrome. They are used as markers and treatment of cardiac failure. Other applications are on going. BNP and NT-proBNP (inactive portion de la pro-hormone) are used as markers of cardiac failure since they have a longer half-life than ANP. BNP decrease is quicker and more important than that one of NT-ProBNP in case of improvement of cardiac failure. Chronic renal insufficiency and beta-blockers increase BNP levels. BNP measurement is useless under treatment with neprilysine inhibitors such as sacubitril, one of the neutral endopeptidases involved in catabolism of natriuretic peptides. The association sacubitril/valsartan is a new treatment of chronic cardiac failure, acting through the decrease of ANP catabolism.

[Dynamic changes of brain natriuretic peptide concentration and its diagnostic value for heart failure in early phase of acute myocardial infarction]

OBJECTIVE

To explore the dynamic changes in brain natriuretic peptide (BNP) concentration and the diagnostic value of BNP for heart failure at different time points in the early phase of acute myocardial infarction (AMI).

METHODS

AMI patients who were admitted in our department between January 1, 2016 and July 31, 2016 and underwent emergency percutaneous coronary intervention (PCI) within 12 h after onset were enrolled in this study. All the patients received bedside examinations of BNP concentration and clinical cardiac function within 1 h after PCI and at 12, 20, 24 and 48 h after the onset of AMI. According to the peak BNP concentration, the patients were divided into high peak BNP group (> 400 pg/mL) and normal peak BNP group (≤400 pg/mL).

RESULTS

Seventy patients were enrolled in the study. Within 48 h after AMI onset, BNP concentration variations followed a pattern of an initial increase till reaching the peak concentration at 20 to 24 h, with subsequent gradual decrease. BNP concentrations differed significantly among the indicated time points (χ²=141.7, P < 0.05) except for those between 20 h and 24 h (χ²=0.173, P > 0.05). Compared with those in normal peak BNP group, the patients in high peak BNP group had an older age, a lower BMI, a longer time to perfusion, and a higher likeliness of anterior myocardial infarction and pulmonary infection (P < 0.05). Logistic regression analysis showed that age, BMI and anterior myocardial infarction were independently associated with the increase of peak BNP concentration. ROC curve analysis showed that BNP concentration within 1 h after emergency PCI was unable to diagnose heart failure at that time (P > 0.05), while BNP concentrations at 12, 20, 24 and 48 h after AMI onset had significant diagnostic values for heart failure (P < 0.05) with areas under ROC of 0.860, 0.786, 0.768 and 0.863, and optimal cutoff values of 156.5, 313.7, 240.9 and 285.9 pg/mL, respectively.

CONCLUSIONS

BNP concentration increases first and then decreases in the early phase of AMI, and the peak concentration occurs at 20-24 h after the onset. The diagnostic values of BNP concentrations at different time points also vary.

Takotsubo cardiomyopathy: Pathophysiology and role of cardiac biomarkers in differential diagnosis

Takotsubo cardiomyopathy (TC) is characterized by reversible ventricular dysfunction, not limited to the distribution of an epicardial coronary artery. A disease primarily afflicting post-menopausal women, it is frequently mistaken for acute anterior wall myocardial infarction. Alternatively called Stress Cardiomyopathy, physical or emotional triggers are identified in only three fourths of TC patients. Long considered a benign condition, recent findings suggest poor short term prognosis similar to acute coronary syndrome (ACS). Despite the widely recognized pathophysiological role of catecholamine excess, its diagnostic role is uncertain. TC is suspected based on typical wall motion abnormalities in ventriculogram or echocardiogram. Several additional electrocardiographic, laboratory and imaging parameters have been studied with the goal of clinical diagnosis of TC. While several clinical clues differentiate it from ACS, a clinical diagnosis is often elusive leading to avoidable cardiac catheterizations. Natriuretic peptides (NPs), a family of peptide hormones released primarily in response to myocardial stretch, play a significant role in pathophysiology, diagnosis as well as treatment of congestive heart failure. TC with its prominent ventricular dysfunction is associated with a significant elevation of NPs. NPs are elevated in ACS as well but the degree of elevation is typically lesser than in TC. Markers of myocardial injury such as troponin are usually elevated to a higher degree in ACS than in TC. This differential elevation of NPs and markers of myocardial injury may play a role in early clinical recognition of TC.

The Low-Dose (7.5 mg/day) Pioglitazone Therapy

Pioglitazone is one of thiazolidinedione derivatives, which stimulates nuclear peroxisome proliferator-activated receptor gamma and improves glucose and lipid metabolism and insulin sensitivity. A recent systematic review and meta-analysis showed that pioglitazone therapy was associated with a lower risk of major adverse cardiovascular events in patients with pre-diabetes and diabetes. Further, in a cohort study of patients with type 2 diabetes, pioglitazone therapy was associated with a statistically significant decrease in the risk of all-cause mortality. Despite these beneficial effects, the meta-analysis showed that pioglitazone therapy had higher risks of heart failure, bone fractures, edema and weight gain. To find out the efficacy and safety of the low-dose (7.5 mg/day) pioglitazone therapy, we reviewed the dose-response of pioglitazone on favorable effects and adverse effects due to pioglitazone, by searching the reports on effects of daily dose of 7.5 mg and/or 15 mg and/or 30 mg of pioglitazone. The low-dose pioglitazone therapy may show the same degree of improvements in glucose and lipid metabolism, fatty liver, insulin resistance, and adiponectin as the standard- and high-dose pioglitazone therapy. Furthermore, the low-dose pioglitazone therapy may also show less adverse effects on weight gain, edema and heart failure as compared with the standard- and high-dose pioglitazone therapy.

Circulating Noncoding RNAs as Biomarkers of Cardiovascular Disease and Injury

The discovery of thousands of noncoding RNAs (ncRNAs) has expanded our view on mammalian genomes and transcriptomes, as well as their organization and regulation. Accumulating evidence on aberrantly regulated ncRNAs, including short microRNAs, long ncRNAs and circular RNAs, across various heart diseases indicates that ncRNAs are critical contributors to cardiovascular pathophysiology. In addition, ncRNAs are released into the circulation where they are present in concentration levels that differ between healthy subjects and diseased patients. Although little is known about the origin and function of such circulating ncRNAs, these molecules are increasingly recognized as noninvasive and readily accessible biomarker for risk stratification, diagnosis and prognosis of cardiac injury, and multiple forms of cardiovascular disease. In this review, we summarize recent findings on biological characteristics of circulating ncRNAs and highlight their value as potential biomarker in selected pathologies of cardiovascular disease.

Significance of NT-pro-BNP in acute exacerbation of COPD patients without underlying left ventricular dysfunction

BACKGROUND

B-type natriuretic peptide (BNP) and the N-terminal fragment of pro-BNP (NT-pro-BNP) are established biomarkers of heart failure. Increased levels of natriuretic peptide (NP) have been associated with poor outcomes in acute exacerbation of COPD (AECOPD); however, most studies did not address the conditions that can also increase NT-pro-BNP levels. We aimed to determine if NT-pro-BNP levels correlate with outcomes of AECOPD in patients without heart failure and other conditions that can affect NT-pro-BNP levels.

METHODS

We conducted a retrospective study in patients hospitalized for AECOPD with available NT-pro-BNP levels and normal left ventricular ejection fraction. We compared patients with normal and elevated NT-pro-BNP levels and analyzed the clinical and outcome data.

RESULTS

A total of 167 of 1,420 (11.7%) patients met the study criteria. A total of 77% of male patients and 53% of female patients had elevated NT-pro-BNP levels (P=0.0031). NT-pro-BNP levels were not associated with COPD severity and comorbid illnesses. Log-transformed NT-pro-BNP levels were positively associated with echocardiographically estimated right ventricular systolic pressure (r=0.3658; 95% confidence interval [CI]: 0.2060-0.5067; P<0.0001). Patients with elevated NT-pro-BNP levels were more likely to require intensive care (63% vs 43%; P=0.0207) and had a longer hospital length of stay (P=0.0052). There were no differences in the need for noninvasive positive pressure ventilation (P=0.1245) or mechanical ventilation (P=0.9824) or in regard to in-hospital mortality (P=0.5273).

CONCLUSION

Patients with AECOPD and elevated NT-pro-BNP levels had increased hospital length of stay and need for intensive care. Based on our study, serum NT-pro-BNP levels cannot be used as a biomarker for increased mortality or requirement for invasive or noninvasive ventilation in this group of patients.

Atrial natriuretic peptide: A novel mediator for TGF-β1-induced epithelial-mesenchymal transition in 16HBE-14o and A549 cells

Atrial natriuretic peptide (ANP) is increasingly expressed on airway and inhibits pulmonary arterial remodeling. However, the role of ANP in remodeling of respiratory system is still unclear. The role of ANP on airway remodeling and the possible mechanism was explored in this study. Both human bronchial epithelial 16HBE-14o cells and alveolar epithelial A549 cells were stimulated by TGF-β1, ANP, cGMP inhibitor, PKG inhibitor, and cGMP analogue. The expressions of epithelial markers, mesenchymal markers, and Smad3 were assessed by quantitative real-time PCR and western blotting. Immunohistochemical staining was employed to assess Smad3 expression once it was silenced by siRNA in 16HBE-14o or A549 cells. Our results showed that the mRNA and protein expressions of E-Cadherin were decreased, whereas α-SMA expressions were increased after induction by TGF-β1 in 16HBE-14o and A549 cells. The E-Cadherin expressions were increased and α-SMA expressions were decreased after ANP stimulation. Inhibition of cGMP or PKG decreased E-Cadherin expression but increased α-SMA expression, which could be reversed by cGMP analogue. Moreover, the phosphorylated Smad3 expression was consistent with α-SMA expression. After smad3 was silenced, Smad3 was mostly expressed in cytoplasm instead of nucleus as non-silenced cells during epithelial-mesenchymal transition (EMT). In conclusion, ANP inhibits TGF-β1-induced EMT in 16HBE-14o and A549 cells through cGMP/PKG signaling, by which it targets TGF-β1/Smad3 via attenuating phosphorylation of Smad3. These findings suggest the potential of ANP in the treatment on pulmonary diseases with airway remodeling.

Challenges of Treating Acute Heart Failure in Patients with Chronic Obstructive Pulmonary Disease

Heart failure (HF) and chronic obstructive pulmonary disease (COPD) comorbidity poses substantial diagnostic and therapeutic challenges in acute care settings. The specific role of pulmonary comorbidity in the treatment and outcomes of cardiovascular disease patients was not addressed in any short- or long-term prospective study. Both HF and COPD can be interpreted as systemic disorders associated with low-grade inflammation, endothelial dysfunction, vascular remodelling and skeletal muscle atrophy. HF is regularly treated as a broader cardiopulmonary syndrome utilising acute respiratory therapy. Based on observational data and clinical expertise, a management strategy of concurrent HF and COPD in acute settings is suggested. Concomitant use of beta2-agonists and beta-blockers in a comorbid cardiopulmonary condition seems to be safe and effective.

C-reactive protein and N-terminal prohormone brain natriuretic peptide as biomarkers in acute exacerbations of COPD leading to hospitalizations

There are currently no accepted and validated blood tests available for diagnosing acute exacerbations of chronic obstructive pulmonary disease (AECOPD). In this study, we sought to determine the discriminatory power of blood C-reactive protein (CRP) and N-terminal prohormone brain natriuretic peptide (NT-proBNP) in the diagnosis of AECOPD requiring hospitalizations. The study cohort consisted of 468 patients recruited in the COPD Rapid Transition Program who were hospitalized with a primary diagnosis of AECOPD, and 110 stable COPD patients who served as controls. Logistic regression was used to build a classification model to separate AECOPD from convalescent or stable COPD patients. Performance was assessed using an independent validation set of patients who were not included in the discovery set. Serum CRP and whole blood NT-proBNP concentrations were highest at the time of hospitalization and progressively decreased over time. Of the 3 classification models, the one with both CRP and NT-proBNP had the highest AUC in discriminating AECOPD (cross-validated AUC of 0.80). These data were replicated in a validation cohort with an AUC of 0.88. A combination of CRP and NT-proBNP can reasonably discriminate AECOPD requiring hospitalization versus clinical stability and can be used to rapidly diagnose patients requiring hospitalization for AECOPD.