Natriuretic peptides in heart failure: where we are, where we are going

Novel concept to guide systolic heart failure medication by repeated biomarker testing-results from TIME-CHF in context of predictive, preventive, and personalized medicine

Background

It is uncertain whether repeated measurements of a multi-target biomarker panel may help to personalize medical heart failure (HF) therapy to improve outcome in chronic HF.

Methods

This analysis included 499 patients from the Trial of Intensified versus standard Medical therapy in Elderly patients with Congestive Heart Failure (TIME-CHF), aged ≥ 60 years, LVEF ≤ 45%, and NYHA ≥ II, who had repeated clinical visits within 19 months follow-up. The interaction between repeated measurements of biomarkers and treatment effects of loop diuretics, spironolactone, β-blockers, and renin-angiotensin system (RAS) inhibitors on risk of HF hospitalization or death was investigated in a hypothesis-generating analysis. Generalized estimating equation (GEE) models were used to account for the correlation between recurrences of events in a patient.

Results

One hundred patients (20%) had just one event (HF hospitalization or death) and 87 (17.4%) had at least two events. Loop diuretic up-titration had a beneficial effect for patients with high interleukin-6 (IL6) or high high-sensitivity C-reactive protein (hsCRP) (interaction, P = 0.013 and P = 0.001), whereas the opposite was the case with low hsCRP (interaction, P = 0.013). Higher dosage of loop diuretics was associated with poor outcome in patients with high blood urea nitrogen (BUN) or prealbumin (interaction, P = 0.006 and P = 0.001), but not in those with low levels of these biomarkers. Spironolactone up-titration was associated with lower risk of HF hospitalization or death in patients with high cystatin C (CysC) (interaction, P = 0.021). β-Blockers up-titration might have a beneficial effect in patients with low soluble fms-like tyrosine kinase-1 (sFlt) (interaction, P = 0.021). No treatment biomarker interactions were found for RAS inhibition.

Conclusion

The data of this post hoc analysis suggest that decision-making using repeated biomarker measurements may be very promising in bringing treatment of heart failure to a new level in the context of predictive, preventive, and personalized medicine. Clearly, prospective testing is needed before this novel concept can be adopted.

Clinical trial registration

isrctn.org, identifier: ISRCTN43596477

Electronic supplementary material

The online version of this article (10.1007/s13167-018-0137-7) contains supplementary material, which is available to authorized users.

Usefulness of amino terminal pro-B-type natriuretic peptide in evaluating children with cardiac failure

BACKGROUND

The plasma levels of amino terminal pro-B type natriuretic peptide (NT-proBNP) have been found to be useful in evaluating children with heart failure in developed countries where the cause is mainly structural heart lesions. There is paucity of similar studies from developing countries where the causes are mostly of infectious origin. This article is aim to evaluate the relationship between plasma NT-proBNP levels and the severity, outcome and duration of admission of children with heart failure.

METHODS

The subjects were children presenting to the children's emergency room (CHER) diagnosed with heart failure based on the modified Ross criteria. The controls were age matched well children recruited from follow up clinics. Information on bio-data and socio-demographics was collected while blood was obtained for plasma NT-proBNP measurement. Data analysis was done with SPSS.

RESULTS

One hundred and twenty six subjects and same number of controls aged 2 months to 13 years were recruited. The mean plasma NT-proBNP in the subjects was 1,137.10±1,243.78 ng/L and in controls, 578.00±665.08 ng/L (t=5.669, P<0.001). Subjects with severe heart failure had a statistically significantly higher mean plasma NT-proBNP than those with mild or moderate categories (P<0.001). A plasma NT-proBNP of 903.15 ng/L had a 73.3% sensitivity and 72.1% specificity for identifying severe heart failure using receiver operating curve (ROC) analysis (95% CI, 0.659-0.912, P<0.001).

CONCLUSIONS

Children with heart failure had significantly higher mean NT-proBNP value than controls and the value was highest in those with severe form of heart failure compared to those with moderate or mild categories. Plasma NT-proBNP should be determined for children presenting with clinically diagnosed heart failure to identify those with severe heart failure and institute prompt treatment.

Predictors of Mortality in Paediatric Myocarditis

INTRODUCTION

Paediatric myocarditis can present as mild flu like symptoms to fulminent form. Early identification of the severity of illness and prioritization of intensive care is helpful especially in developing countries with limited resources.

AIM

To know the factors at admission that can predict mortality in paediatric myocarditis.

MATERIALS AND METHODS

This was an observational study which enrolled children who presented with fever of acute onset (less than 15 days in duration), and were diagnosed as suspected myocarditis on the basis of clinical features, Troponin I and echocardiography, according to Expanded criteria for myocarditis in Paediatric ward at our institute over a period from August 2014 to December 2015. Their clinical features, cardiac biomarkers and echocardiography findings were compared between survivors and non-survivors.

STATISTICAL ANALYSIS

All statistical analysis was done using graphpad Prism 5 and SPSS statistical software. A Fisher exact p-value <0.05 was regarded as significant. Multivariate Logistic Regression was carried out to quantify the relationship between cardiac death and other predictor variables. The logistic coefficients for the predictor variables and their exponents, that is, log odds were calculated. Statistical significance of these predictor variables was interpreted by p-values.

RESULTS

A 17.7% (n=11/62) patients of paediatric myocarditis died in this study. New York Heart Association (NYHA) class IV dyspnea (p=0.0115) and hypotension (p=0.0174) were more in patients who did not survive. The mean value of Troponin I was more in the non-survivor group (0.958 ± 1.13ng/ml); (p=0.0074). More number of patients who died had Brain Natriuretic Peptide (BNP) levels increased in their plasma (p=0.0087) with higher mean value (p=0.0175). LV ejection fraction was decreased markedly in non survivor group with mean value of 37±8.09 % as compared to survivor group with mean value of 46.6±10.5%, (p=0.0115). On multivariate analysis, NYHA class IV dyspnea (p=0.0113), BNP (p=0.015) and ejection fraction (p = 0.0284) independently are the predictors of mortality in our study group.

CONCLUSION

Children with myocarditis having hypotension, raised Troponin I, BNP and decreased ejection fraction are more prone to die. NYHA IV dyspnea, higher levels of BNP and decreased EF are independently related to worst outcome.

The usefulness of brain natriuretic peptide level in diagnosis and prognosis of patients admitted to critical care unit with shortness of breath

Background:

Brain Natriuretic Peptide (BNP) is a polypeptide secreted by the ventricles as a response to cardio-myocyte stretching. Due to its cardiac origin and correlation with volume overload it has been successfully used for a long time in diagnosing and prognosticating Cardiogenic Pulmonary Edema.

Materials and Methods:

In this retrospective cohort study, an attempt was made to observe any correlation between admission BNP levels with APACHE II scores and length of ICU stay, in patients admitted with dyspnea to the ICU of a community based hospital.

Results/Conclusion:

This study showed no significant correlation between length of stay in an ICU and admission BNP levels in dyspneic patients. Independent variables such as age and gender failed to show any coorelation either.

DPP-4 inhibitors: focus on safety

INTRODUCTION

Dipeptidyl peptidase inhibitors (DPP-4-i) are highly selective inhibitors of the enzyme DPP-4. They act by increasing levels of incretin hormones, which have potent effects on insulin and glucagon release, gastric emptying, and satiety. Our goal is to review the safety issues related to DPP-4-i.

AREAS COVERED

This review is based upon a PubMed search of the literature using keywords alogliptin, linagliptin, saxagliptin, sitagliptin and vildagliptin, DPP-4-i, glucagon-like polypeptide-1 agonists, as well as extensive personal clinical trial experience with each of these agents. The current DPP-4-i have very different chemical structures. Saxagliptin has significant cytochrome P450 metabolism and carries a risk of drug interactions. Linagliptin has primarily entero-hepatic excretion, a benefit in renally impaired patients. A concern arose related to congestive heart failure in the SAVOR TIMI trial of saxagliptin. Several major cardiac studies are underway, with two concluded. Despite lingering uncertainty related to pancreatitis and pancreatic cancer, large randomized trials have not shown an increased risk with DPP-4-i treatment. Cutaneous adverse effects occur with a low frequency with some of these agents.

EXPERT OPINION

DPP-4-i are an additional choice in the group of anti-hyperglycemics. Their principal advantage is a low incidence of hypoglycemia, making these agents desirable in patients such as the elderly and those with cardiac disease. Several large trials have hinted at less cardiac risk with DPP-4-i than with sulfonylureas. The CAROLINA Trial comparing linagliptin and glimepiride may provide a conclusive answer to this question.

Clinical relevance of biomarkers in heart failure and cardiorenal syndrome: the role of natriuretic peptides and troponin

In recent years, numerous biomarkers have been studied in heart failure to improve diagnostic accuracy and identify patients at higher risk. The overall outcome remains fairish despite improvements in therapy, with mean survival after first hospitalization, around 5 years. We therefore need surrogate end points to better understand the pathogenetic mechanisms of the disease, including interplays with other organs. The kidney plays an important role in the initiation and progression of HF, and around one-third of patients with HF show some degree of renal dysfunction. In addition, treatment for HF often worsens renal function, consequently to hemodynamic and clinical improvement do not correspond an effective improvement in HF prognosis. Association between HF and renal impairment (RI) is now classified as cardiorenal syndrome (CRS) pointing out the bidirectional nature of this vicious circle leading to a mutual and progressive damage of both organs. The clinicians can rely on circulating biomarkers that give insights into the underlying pathogenetic mechanisms and help in risk stratification. Recently, a multimarker strategy including biomarker tool to traditional risk scores has been purposed and applied: Although each biomarker provided incremental outcome benefit, the combination of multiple biomarkers should offer the greatest improvement in risk prediction. Natriuretic peptides (NP) and cardiac troponins (TN) are the two biomarkers most studied in this setting, probably because of their organ-specific nature. However, both NP and TN cutoffs in presence of renal dysfunction need to be revised and discussed in relation to age, gender and stage of RI. In this context, the biomarkers are a unique opportunity to elucidate pathophysiological mechanisms, tailor clinical management to the single patient and improve outcomes. Specific studies about the exact role of biomarkers as in HF as in CRS should be planned and considered for future trials.

Incretin-based therapies: can we achieve glycemic control and cardioprotection?

Glucagon-like (GLP-1) is a peptide hormone secreted from the small intestine in response to nutrient ingestion. GLP-1 stimulates insulin secretion in a glucose-dependent manner, inhibits glucagon secretion and gastric emptying, and reduces appetite. Because of the short circulating half-life of the native GLP-1, novel GLP-1 receptor (GLP-1R) agonists and analogs and dipeptidyl peptidase 4 (DPP-4) inhibitors have been developed to facilitate clinical use. Emerging evidence indicates that GLP-1-based therapies are safe and may provide cardiovascular (CV) benefits beyond glycemic control. Preclinical and clinical studies are providing increasing evidence that GLP-1 therapies may positively affect CV function and metabolism by salutary effects on CV risk factors as well as via direct cardioprotective actions. However, the mechanisms whereby the various classes of incretin-based therapies exert CV effects may be mechanistically distinct and may not necessarily lead to similar CV outcomes. In this review, we will discuss the potential mechanisms and current understanding of CV benefits of native GLP-1, GLP-1R agonists and analogs, and of DPP-4 inhibitor therapies as a means to compare their putative CV benefits.

Proteomic biomarkers of recovered heart function

AIMS

Chronic heart failure is a costly epidemic that affects up to 2% of people in developed countries. The purpose of this study was to discover novel blood proteomic biomarker signatures of recovered heart function that could lead to more effective heart failure patient management by both primary care and specialty physicians.

METHODS AND RESULTS

The discovery cohort included 41 heart transplant patients and 20 healthy individuals. Plasma levels of 138 proteins were detected in at least 75% of these subjects by iTRAQ mass spectrometry. Eighteen proteins were identified that had (i) differential levels between pre-transplant patients with end-stage heart failure and healthy individuals; and (ii) levels that returned to normal by 1 month post-transplant in patients with stable heart function after transplantation. Seventeen of the 18 markers were validated by multiple reaction monitoring mass spectrometry in a cohort of 39 heart failure patients treated with drug therapy, of which 30 had recovered heart function and 9 had not. This 17-protein biomarker panel had 93% sensitivity and 89% specificity, while the RAMP® NT-proBNP assay had the same specificity but 80% sensitivity. Performance further improved when the panel was combined with NT-proBNP, yielding a net reclassification index relative to NT-proBNP of 0.28.

CONCLUSIONS

We have identified potential blood biomarkers of recovered heart function by harnessing data from transplant patients. These biomarkers can lead to the development of an inexpensive protein-based blood test that could be used by physicians to monitor response to therapy in heart failure, resulting in more personalized, front-line heart failure patient management.

Relative Change in NT-proBNP Level: An Important Risk Predictor of Cardiovascular Congestion in Haemodialysis Patients

Background

Cross-sectional studies have shown that B-type natriuretic peptide (BNP) and its N-terminal fragment (NT-proBNP) are predictive of cardiovascular death in haemodialysis (HD) patients. In the present study, we tested the hypothesis that monitoring NT-proBNP measurements adds further prognostic information, i.e. predicts congestive heart failure (CHF) events.

Methods

In a prospective cohort of 236 HD patients, NT-proBNP levels were measured monthly during 18 months. Patients were divided according to the occurrence of CHF events. In a nested case-control study, we assessed the evolution of NT-proBNP levels.

Results

On average, the 236 HD patients were followed up for 12.5 months, a period during which 44 patients developed a CHF event (half requiring hospitalisation). At baseline, patients who developed a CHF event had significantly more dilated cardiomyopathy and/or altered left ventricular ejection fraction and higher NT-proBNP levels compared with patients who did not develop a CHF event. During follow-up, we observed a significant increase in NT-proBNP levels preceding the CHF event. At a 20% relative increase of NT-proBNP, the sensitivity of NT-proBNP as a predictor of CHF events was 0.57 and the specificity 0.77.

Conclusion

The relative change in NT-proBNP levels is a significant risk predictor of a CHF event.

Clinical utility of novel biomarkers for cardiovascular disease risk stratification

Over the past few decades, a number of coronary artery disease (CAD) and cardiovascular disease (CVD) risk factors have been identified. The predictive power of "conventional" risk factors have been validated by observational, prospective and intervention studies. Nevertheless, all attempts to exactly predict the individual risk for CAD have failed, biased by a large number of incorrectly risk-classified subjects. To improve cardiovascular (CV) risk prediction, a large number of genetic and/or non-genetic biomarkers have been discovered and tested against the "classical" risk factors for their power to predict CV risk. Only few of them had a significant improvement over the predictive models. In this paper, the most investigated biomarkers will be discussed and the evidence of their use as predictors of CV will be questioned.

Hyperthermia by bathing in a hot spring improves cardiovascular functions and reduces the production of inflammatory cytokines in patients with chronic heart failure

Balneotherapy has been shown to reduce systemic blood pressure in healthy volunteers. Hyperthermia might ameliorate the inflammatory status in heart failure through improving cardiac function. The purpose of this study was to examine the beneficial effects of balneotherapy in patients with chronic heart failure (CHF). Thirty-two patients with systolic CHF classified as New York Heart Association functional status II or III were randomized to divide either a balneotherapy group or a control group. The patients in the balneotherapy group were immersed in a hot spring at 40°C for 10 min daily for 2 weeks; the control group patients took a shower daily. The left ventricular ejection fraction (EF) and cardiothoracic ratio (CTR) were evaluated and plasma brain natriuretic peptide (BNP), high-sensitivity C-reactive protein (hsCRP), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 levels were measured. The clinical symptoms improved after 2 weeks of hot spring therapy. Although the heart rate did not change, clinical symptoms, CTR, EF, and BNP were significantly improved. Moreover, the inflammatory responses, including hsCRP, TNF-α and IL-6 decreased significantly after balneotherapy. The improvement of BNP correlates with the changes in inflammatory biomarkers. Repeated hyperthermia by bathing in a hot spring is therefore considered to improve the cardiac and inflammatory status in patients with CHF.

Clinical Use of Natriuretic Peptides

Either B-type natriuretic peptide (BNP) or NT-proBNP may be used as a diagnostic, screening, prognostic and therapeutic tool for CHF. The Food and Drug Administration (FDA) cleared the cut-off point for BNP at 100 pg/mL, and that of NT-proBNP at 125 pg/mL for patients <75 years and 450 pg/mL for those >75. A steadily rising titre even below the cut-off value should be raised as a concern as heart failure is progressive if left untreated and may result in cardiac death. Both biomarkers are also featured in lab investigations for patients with acute coronary syndrome (ACS).

B-type natriuretic peptide: from posttranslational processing to clinical measurement

BACKGROUND

Plasma cardiac natriuretic peptides and peptide fragments from their molecular precursors are markers of heart disease. Clinical studies have defined the current diagnostic utility of these markers, whereas biochemical elucidation of peptide structure and posttranslational processing has revealed new plasma peptide forms of potential clinical use.

CONTENT

Natriuretic propeptide structures undergo variable degrees of endo- and exoproteolytic cleavages as well as amino acid modifications, which leave the plasma phase of the peptides highly heterogeneous and dependent on cardiac pathophysiology and capacity. An ongoing characterization of the molecular heterogeneity may not only help us to appreciate the biosynthetic capacity of the endocrine heart but may also lead to the discovery of new and more disease-specific targets for future molecular diagnosis.

SUMMARY

Peptides derived from pro-atrial natriuretic peptide and pro-B-type natriuretic peptide are useful plasma markers in heart failure. New data have defined cardiac myocytes as competent endocrine cells in posttranslational processing and cellular secretion.