Natriuretic peptides as biomarkers of cardiac endocrine function in heart failure: new challenges and perspectives

NT-proBNP levels as a predictor of higher left ventricular end-diastolic pressure in children with small perimembranous ventricular septal defect

INTRODUCTION

The decision to close small ventricular septal defect is still controversial. Previous study showed that ventricular dysfunction in adulthood is correlated with small perimembranous ventricular septal defect. N terminal pro B-type natriuretic peptide (NT-proBNP) is a neurohormone secreted primarily from the ventricles in response to increased left and right ventricular pressure and volume load. The left ventricular end-diastolic pressure will reflect ventricular performance. This study aimed to evaluate the correlation between left ventricular end-diastolic pressure and the NT-proBNP in children with small perimembranous ventricular septal defect.

MATERIALS AND METHODS

Level of NT-proBNP in 41 patients with small perimembranous ventricular septal defect was measured before transcatheter closure procedure. We also measured the left ventricular end-diastolic pressure in each patients during catheterisation. We investigated the value of NT-proBNP in patients with small perimembranous ventricular septal defect and its correlation with the level of left ventricular end-diastolic pressure.

RESULT

We found positive correlation between NT-proBNP and left ventricular end-diastolic pressure (r = 0.278, p = 0.046). The median of NT-proBNP at left ventricular end-diastolic pressure < 10 was lower than at left ventricular end-diastolic pressure ≥ 10 (0.87 ng/ml versus 1.83 ng/ml, p = 0.023). The results of the NT-proBNP diagnostic test for predicting left ventricular end-diastolic pressure ≥ 10 using Receiver Operating Characteristic (ROC) analysis showed the area under the curve value of 0.715 (95% CI: 0.546-0.849). The cut-off value >0.99 ng/ml of NT-proBNP has 75.0% sensitivity and 72.2% specifity.

CONCLUSION

Level of NT-proBNP higher than 0.99 ng/ml was correlated significantly with left ventricular end-diastolic pressure ≥10 in children with small perimembranous ventricular septal defect.

Inflammageing and Cardiovascular System: Focus on Cardiokines and Cardiac-Specific Biomarkers

The term "inflammageing" was introduced in 2000, with the aim of describing the chronic inflammatory state typical of elderly individuals, which is characterized by a combination of elevated levels of inflammatory biomarkers, a high burden of comorbidities, an elevated risk of disability, frailty, and premature death. Inflammageing is a hallmark of various cardiovascular diseases, including atherosclerosis, hypertension, and rapid progression to heart failure. The great experimental and clinical evidence accumulated in recent years has clearly demonstrated that early detection and counteraction of inflammageing is a promising strategy not only to prevent cardiovascular disease, but also to slow down the progressive decline of health that occurs with ageing. It is conceivable that beneficial effects of counteracting inflammageing should be most effective if implemented in the early stages, when the compensatory capacity of the organism is not completely exhausted. Early interventions and treatments require early diagnosis using reliable and cost-effective biomarkers. Indeed, recent clinical studies have demonstrated that cardiac-specific biomarkers (i.e., cardiac natriuretic peptides and cardiac troponins) are able to identify, even in the general population, the individuals at highest risk of progression to heart failure. However, further clinical studies are needed to better understand the usefulness and cost/benefit ratio of cardiac-specific biomarkers as potential targets in preventive and therapeutic strategies for early detection and counteraction of inflammageing mechanisms and in this way slowing the progressive decline of health that occurs with ageing.

Pathophysiology and molecular signalling in pediatric heart failure and VAD therapy

Heart Failure (HF) is a progressive clinical syndrome characterized by molecular and structural abnormalities that result in impaired ventricular filling and a reduced blood ejection. In pediatric patients, HF represents an important cause of morbidity and mortality, but underlying cause, presentation and disease course remains unclear in many cases. It is evident that a child is not a "small adult" and findings are not comparable. The adoption of a standardized clinical and surgical tools as well as increased biomolecular research and therapeutic trials targeting pediatric patients with HF would greatly improve the management of this special class of patients. This review examines the most current information about the pathophysiology and molecular mechanisms related to HF in children to identify gaps in our knowledge base to further improve clinical care and outcomes.

N-terminal pro-B-type natriuretic peptide levels in children: comparison in cardiac and non-cardiac diseases

BACKGROUND

N-terminal pro-B-type natriuretic peptide (NT-proBNP), a well-known marker of cardiac disease, may be elevated in acute infections and other non-cardiac diseases. The aim of this study was to evaluate NT-proBNP levels in cardiac and non-cardiac diseases and found out the patient's clinical status that affects the NT-proBNP levels.

METHODS

NT-proBNP levels were measured in three groups of children: a cardiac disease group, an infectious disease group, and a non-cardiac, non-infectious disease group.

RESULT

In total, 348 children were enrolled, including 134 patients (38.5%) with cardiac disease, 170 patients (48.9%) with infectious disease, and 44 patients (12.6%) with non-cardiac, non-infectious disease. The NT-proBNP level of the cardiac disease group (median: 548 pg/mL; range: 5-35,000 pg/mL) was significantly higher than that of the infectious disease group (median: 193 pg/mL; range: 10-35,000 pg/mL) and the non-cardiac, non-infectious disease group (median: 280 pg/mL; range: 6-35,000 pg/mL). Regarding clinical status, the NT-proBNP levels were significantly higher in patients who needed mechanical ventilation support, oxygen therapy, or inotropic medication or had a change in mental status than in other patients. However, the systemic inflammatory response syndrome and mortality were not related to the NT-proBNP level.

CONCLUSION

Among heterogeneous group of children, NT-proBNP level can be a useful marker of cardiac disease. Furthermore, the NT-proBNP levels were related to patients' clinical deteriorations, such as shock rather than the inflammatory status of patients.

The therapeutic effect of B-type natriuretic peptides in acute decompensated heart failure

B-type natriuretic peptide (BNP) exhibits roles in natriuresis and diuresis, making it an ideal drug that may aid in diuresing a fluid-overloaded patient with poor or worsening renal function. Several randomized clinical trials have tested the hypothesis that infusions of pharmacological doses of BNP to acute heart failure (HF) patients may enhance decongestion and preserve renal function in this clinical setting. Unfortunately, none of these have demonstrated beneficial outcomes. The current challenge for BNP research in acute HF lies in addressing a failure of concept and a reluctance to abandon an ineffective research model. Future success will necessitate a detailed understanding of the mechanism of action of BNP, as well as better integration of basic and clinical science.

NT-proBNP to exclude heart failure in primary care - a pragmatic, cluster-randomized study

Heart failure (HF) is difficult to recognize in primary care. N-terminal pro B-type natriuretic peptide (NT-proBNP) can be used as a rule-out test in HF due to its high negative predictive value. We aim to determine whether the number per 1000 patients of HF diagnoses increase among patients referred from primary care to an outpatient HF clinic, if general practitioners (GPs) were offered NT-proBNP in a real-life setting. All GP practices covered by Randers Regional Hospital were randomized to an intervention group (34 GP practices) and a control group (35 GP practices) in this pragmatic, cluster-randomized controlled trial. The main outcome was the number of patients referred to echocardiography and diagnosed with HF in each group. The number of patients per 1000 diagnosed with HF in the two groups was the same (0.09 (0.02-0.16) vs. 0.14 (0.07-0.21), p = .3541). A total of 700 NT-proBNP analyses, of which 611 were unique, were requested from 31 GP practices in 17.5 months. A total of 184 patients were referred to echocardiography on suspicion of HF. The number of patients per 1000 referred in the intervention group was significantly higher (p < .010). NT-proBNP was measured in 36.6% of referred patients in the intervention group. Significantly more women were diagnosed with HF in the intervention group (56.3% vs. 0%, p = .019). Hence, increased diagnostic effectiveness could not be shown in this real-life setting.

Stress Coping Strategies in the Heart: An Integrated View

The heart is made up of an ordered amalgam of cardiac cell types that work together to coordinate four major processes, namely energy production, electrical conductance, mechanical work, and tissue remodeling. Over the last decade, a large body of information has been amassed regarding how different cardiac cell types respond to cellular stress that affect the functionality of their elaborate intracellular membrane networks, the cellular reticular network. In the context of the heart, the manifestations of stress coping strategies likely differ depending on the coping strategy outcomes of the different cardiac cell types, and thus may underlie the development of distinct cardiac disorders. It is not clear whether all cardiac cell types have similar sensitivity to cellular stress, how specific coping response strategies modify their unique roles, and how their metabolic status is communicated to other cells within the heart. Here we discuss our understanding of the roles of specialized cardiac cells that together make the heart function as an organ with the ability to pump blood continuously and follow a regular rhythm.

Evolution of natriuretic peptide biomarkers in heart failure: Implications for clinical care and clinical trials

Natriuretic peptides (NPs) are recommended by international guidelines to exclude non-heart failure causes of acute dyspnea and to assess prognosis. NPs are commonly used as an entry criterion for clinical trials, to minimize enrollment of misdiagnosed patients, or to ensure enrollment of a sufficiently at-risk population. NP values used to select trial populations to date have been inconsistent across studies. Future trials should consider using standardized thresholds for NP levels, with protocol-specified adaptations appropriate for the specific study and patient population to account for factors that can influence the NP level. NPs have been used as an endpoint for proof-of-concept or phase 2 clinical trials, although it is important to remember that positive results in early phase studies may be unstable due to small numbers and the play of chance, and they are not always reproducible in phase 3 trials. Likewise, failure to reduce NP in phase 2 may not necessarily indicate that a drug will be ineffective on clinical outcomes in phase 3. NP guided therapy has been intensively studied, but the clinical outcome benefits of this approach remain uncertain. Neprilysin inhibitors have stimulated further exploration of the NP system and how it influences, and is potentially influenced by, heart failure therapies. This paper discusses the utility of NPs in the current clinical research and practice environment and addresses areas in need of further research from the perspectives of academic clinical trialists, clinicians, biostatisticians, regulators, and pharmaceutical industry scientists who participated in the 13th Global Cardiovascular Clinical Trialists Forum.