Acute study of clinical effectiveness of nesiritide in decompensated heart failure: nesiritide redux

Declining Risk of Sudden Cardiac Death in Heart Failure: Fact or Myth?

The notion that the risk of sudden cardiac death (SCD) in patients with heart failure (HF) is declining seems to be gaining traction. Numerous editorials and commentaries have suggested that SCD, specifically arrhythmic SCD, is no longer a significant risk for patients with HF on guideline-directed medical therapy. In this review, we question whether the risk of SCD has indeed declined in HF trials and in the real world. We also explore whether, despite relative risk reductions, the residual SCD risk after guideline-directed medical therapy still suggests a need for implantable cardioverter defibrillator therapy. Among our arguments is that SCD has not decreased in HF trials, nor in the real world. Moreover, we argue that data from HF trials, which have not adhered to guideline-directed device therapy, do not obviate or justify delays to implantable cardioverter defibrillator therapy. In this context, we underline the challenges of translating the findings of HF randomized, controlled trials of guideline-directed medical therapy to the real world. We also make the case for HF trials that adhere to current guideline-directed device therapy so that we can better understand the role of implantable cardioverter defibrillators in chronic HF.

Pharmacological interventions for heart failure in people with chronic kidney disease

BACKGROUND

Approximately half of people with heart failure have chronic kidney disease (CKD). Pharmacological interventions for heart failure in people with CKD have the potential to reduce death (any cause) or hospitalisations for decompensated heart failure. However, these interventions are of uncertain benefit and may increase the risk of harm, such as hypotension and electrolyte abnormalities, in those with CKD.

OBJECTIVES

This review aims to look at the benefits and harms of pharmacological interventions for HF (i.e., antihypertensive agents, inotropes, and agents that may improve the heart performance indirectly) in people with HF and CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies through 12 September 2019 in consultation with an Information Specialist and using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials of any pharmacological intervention for acute or chronic heart failure, among people of any age with chronic kidney disease of at least three months duration.

DATA COLLECTION AND ANALYSIS

Two authors independently screened the records to identify eligible studies and extracted data on the following dichotomous outcomes: death, hospitalisations, worsening heart failure, worsening kidney function, hyperkalaemia, and hypotension. We used random effects meta-analysis to estimate treatment effects, which we expressed as a risk ratio (RR) with 95% confidence intervals (CI). We assessed the risk of bias using the Cochrane tool. We applied the GRADE methodology to rate the certainty of evidence.

MAIN RESULTS

One hundred and twelve studies met our selection criteria: 15 were studies of adults with CKD; 16 studies were conducted in the general population but provided subgroup data for people with CKD; and 81 studies included individuals with CKD, however, data for this subgroup were not provided. The risk of bias in all 112 studies was frequently high or unclear. Of the 31 studies (23,762 participants) with data on CKD patients, follow-up ranged from three months to five years, and study size ranged from 16 to 2916 participants. In total, 26 studies (19,612 participants) reported disaggregated and extractable data on at least one outcome of interest for our review and were included in our meta-analyses. In acute heart failure, the effects of adenosine A1-receptor antagonists, dopamine, nesiritide, or serelaxin on death, hospitalisations, worsening heart failure or kidney function, hyperkalaemia, hypotension or quality of life were uncertain due to sparse data or were not reported. In chronic heart failure, the effects of angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB) (4 studies, 5003 participants: RR 0.85, 95% CI 0.70 to 1.02; I² = 78%; low certainty evidence), aldosterone antagonists (2 studies, 34 participants: RR 0.61 95% CI 0.06 to 6.59; very low certainty evidence), and vasopressin receptor antagonists (RR 1.26, 95% CI 0.55 to 2.89; 2 studies, 1840 participants; low certainty evidence) on death (any cause) were uncertain. Treatment with beta-blockers may reduce the risk of death (any cause) (4 studies, 3136 participants: RR 0.69, 95% CI 0.60 to 0.79; I² = 0%; moderate certainty evidence). Treatment with ACEi or ARB (2 studies, 1368 participants: RR 0.90, 95% CI 0.43 to 1.90; I² = 97%; very low certainty evidence) had uncertain effects on hospitalisation for heart failure, as treatment estimates were consistent with either benefit or harm. Treatment with beta-blockers may decrease hospitalisation for heart failure (3 studies, 2287 participants: RR 0.67, 95% CI 0.43 to 1.05; I² = 87%; low certainty evidence). Aldosterone antagonists may increase the risk of hyperkalaemia compared to placebo or no treatment (3 studies, 826 participants: RR 2.91, 95% CI 2.03 to 4.17; I² = 0%; low certainty evidence). Renin inhibitors had uncertain risks of hyperkalaemia (2 studies, 142 participants: RR 0.86, 95% CI 0.49 to 1.49; I² = 0%; very low certainty). We were unable to estimate whether treatment with sinus node inhibitors affects the risk of hyperkalaemia, as there were few studies and meta-analysis was not possible. Hyperkalaemia was not reported for the CKD subgroup in studies investigating other therapies. The effects of ACEi or ARB, or aldosterone antagonists on worsening heart failure or kidney function, hypotension, or quality of life were uncertain due to sparse data or were not reported. Effects of anti-arrhythmic agents, digoxin, phosphodiesterase inhibitors, renin inhibitors, sinus node inhibitors, vasodilators, and vasopressin receptor antagonists were very uncertain due to the paucity of studies.

AUTHORS' CONCLUSIONS

The effects of pharmacological interventions for heart failure in people with CKD are uncertain and there is insufficient evidence to inform clinical practice. Study data for treatment outcomes in patients with heart failure and CKD are sparse despite the potential impact of kidney impairment on the benefits and harms of treatment. Future research aimed at analysing existing data in general population HF studies to explore the effect in subgroups of patients with CKD, considering stage of disease, may yield valuable insights for the management of people with HF and CKD.

The virtually mature B-type natriuretic peptide (BNP1-32) is a precursor for the more effective BNP1-30

Background and Purpose

The B‐type natriuretic peptide (BNP1‐32) exerts vasorelaxing and cardioprotective activity. BNP is used as a biomarker for the diagnosis of cardiopathological conditions and recombinant BNP1‐32 as a drug for the treatment of such. BNP1‐32 has a short half‐life and thus, similar to other vasoactive peptides like angiotensin II and bradykinin, can be enzymatically truncated forming bioactive metabolites. We aimed to investigate the metabolism of BNP1‐32 in the mouse lung, to identify potential new BNP metabolites and to disclose their biological activity compared to the BNP1‐32, in vitro and in vivo.

Experimental Approach

Using HPLC and MS, we identified a new BNP metabolite, BNP1‐30, in the lung being generated by endothelin‐converting enzyme‐1.

Key Results

BNP1‐30 is more efficient in stimulating the guanylyl cyclase (GC) receptor A and, in contrast to BNP1‐32, is also able to profoundly stimulate the GC‐B. In vivo, BNP1‐30 reduced the mean arterial BP of normotensive mice after acute infusion significantly more than BNP1‐32. In a model of severe hypertension, a 3‐day infusion of BNP1‐30 was able to reduce systolic BP by 30 mmHg and to improve markers of heart failure, while BNP1‐32 was without significant effect.

Conclusions and Implications

Our results suggest that BNP1‐32 is the precursor for the biologically more active BNP1‐30 leading to a fundamental extension of the natriuretic peptide system. Due to expanded activity, BNP1‐30 might be a promising treatment option for cardiovascular diseases. Furthermore, its potency as a new diagnostic marker of specific cardiac diseases should be evaluated.

Nesiritide Therapy Is Associated With Better Clinical Outcomes Than Dobutamine Therapy in Heart Failure

To evaluate the therapeutic effects of dobutamine and nesiritide in the treatment of heart failure (HF), a meta-analysis of published studies was conducted. Computerized bibliographic databases in Chinese and English languages were carefully searched to identify the relevant literature. A total of 6 cohort studies were enrolled in current meta-analysis for statistical analyses. The effect of dobutamine and nesiritide in patients with HF was estimated by odds ratios (ORs) and 95% confidence interval (CI). Our results revealed a significantly higher survival rate in nesiritide-treated patients, compared with those treated with dobutamine (OR = 1.97; 95% CI, 1.43-2.71; P < 0.001). In addition, a lower readmission rate was also associated with the nesiritide-treated group in comparison with the dobutamine-treated group (OR = 1.96; 95% CI, 1.39-2.78; P < 0.001). A stratified analysis revealed that the subgroup of patients with HF treated with nesiritide showed higher survival outcomes than those patients with HF treated with dobutamine when follow-up period was greater than 6 months (OR = 1.70; 95% CI, 1.21-2.38; P = 0.002) but not under 6 months (P > 0.05). This indicated that nesiritide treatment had longer term benefits as well. Interestingly, based on the reason for readmission, a subgroup analysis of the HF subgroup and the "all-cause" subgroup showed that higher readmission rates were associated with dobutamine treatment in both subgroups (HF: OR = 2.71; 95% CI, = 1.51-4.83; P = 0.001; all-cause: OR = 1.64; 95% CI, 1.06-2.53; P = 0.026; respectively). Our results suggest that nesiritide therapy is associated with a lower in-hospital mortality rates and decreased readmission rates compared with dobutamine treatment in patients with HF.

Natriuretic Peptides and Analytical Barriers

BACKGROUND

The natriuretic peptide system is an endocrine, autocrine and paracrine system that plays an important role in the maintenance of cardiovascular homeostasis. Biomarkers based on these peptides are important diagnostic and prognostic tools for myocardial function.

CONTENT

Although natriuretic peptides were discovered more than 2 decades ago, their intricate and complex biology is associated with important questions not yet elucidated. The diversity of circulating forms of natriuretic peptides, the distinct expression of these forms in particular patients, and the heterogeneity of heart failure forms, along with specific assay-related and preanalytic issues, cause assays to be poorly harmonized.

SUMMARY

This review presents the relevant issues related to the biology of natriuretic peptides and differences between assays with immediate implications for clinical practice.

Different Susceptibility of B-Type Natriuretic Peptide (BNP) and BNP Precursor (proBNP) to Cleavage by Neprilysin: The N-Terminal Part Does Matter

BACKGROUND

Protease neprilysin is known to be responsible for the degradation of natriuretic peptides. A recent heart failure (HF) drug, LCZ696 (EntrestoTM), that combines a neprilysin inhibitor and an angiotensin II receptor inhibitor was suggested to augment circulating B-type natriuretic peptide (BNP) concentrations, making the results of BNP measurements diagnostically ambiguous. Because the main form of measured BNP in HF patients is represented by its uncleaved precursor, proBNP, it is important to know the susceptibility of proBNP to cleavage by neprilysin.

METHODS

BNP 1–32 and nonglycosylated and glycosylated forms of proBNP 1–108 were incubated with neprilysin for different time periods. BNP immunoreactivity was analyzed using 2 sandwich immunoassays: one utilizing monoclonal antibody (mAb) KY-BNP-II (epitope 14–21) as capture with mAb 50E1 (epitope 26–32) for detection and a single-epitope sandwich BNP (SES-BNP) immunoassay specific to the epitope 11–17. Mass-spectrometry was applied to determine the sites of BNP cleavage.

RESULTS

In contrast to BNP, both forms of proBNP were resistant to degradation by neprilysin. The SES-BNP assay was much less susceptible to the BNP cleavage by neprilysin compared with the immunoassay utilizing antibodies specific to the region 14–21, comprising the site Arg17-Ile18, known as the site of BNP cleavage by neprilysin.

CONCLUSIONS

These findings suggest that modulation of neprilysin activity by specific inhibitors may not greatly influence the circulating concentrations of immunoreactive BNP, mostly represented in HF by proBNP, which is not susceptible to neprilysin. The different susceptibility of the BNP regions to neprilysin-dependent degradation highlights the importance of the choice of epitopes for reliable BNP immunodetection.

Dobutamine Therapy is Associated with Worse Clinical Outcomes Compared with Nesiritide Therapy for Acute Decompensated Heart Failure: A Systematic Review and Meta-Analysis

BACKGROUND

Inotropes and natriuretic peptides are essential components of current therapeutic options for acute decompensated heart failure (ADHF). This systematic review examines the therapeutic effectiveness of dobutamine and brain natriuretic peptide, nesiritide, in reducing mortality and readmission rates for ADHF treatment.

METHODS

Published studies related to dobutamine and nesiritide therapy in ADHF were identified via an exhaustive search of scientific literature databases. The identified studies, published between 2002 and 2012, were carefully screened based on our predefined inclusion criteria. Selected studies were pooled, and odds ratios (ORs) and 95% confidence intervals (95% CI) for each outcome were calculated. Subgroup analysis was conducted to assess the influence of ethnicity on the study outcome.

RESULTS

Seven cohort studies were selected for this meta-analysis. These seven studies included 959 ADHF patients who underwent nesiritide treatment and 1748 ADHF patients who received dobutamine therapy. Our meta-analysis revealed a significantly lower survival rate in dobutamine-treated patients compared with nesiritide-treated patients (OR 0.48, 95% CI 0.36-0.63, P < 0.001). Additionally, a markedly higher readmission rate was associated with dobutamine treatment compared with nesiritide treatment (OR 0.52, 95% CI 0.36-0.73, P < 0.001). A stratified analysis based on ethnicity revealed a significantly lower survival in dobutamine-treated ADHF patients in Caucasian and mixed populations compared with nesiritide treatment (Caucasian: OR 0.60, 95% CI 0.38-0.94, P = 0.024; Mixed: OR 0.38, 95% CI 0.26-0.56, P < 0.001). However, a similar association was not detected in Asian populations (P = 0.738). Further, dobutamine-treated ADHF patients displayed higher readmission rates than did nesiritide-treated patients in both Caucasian and mixed-race populations (all P < 0.05).

CONCLUSIONS

Our study suggests that dobutamine therapy is associated with poorer outcomes, with higher in-hospital mortality rates and increased readmission rates compared with nesiritide therapy in ADHF patients. Thus, current treatment strategies need to be redesigned for better outcomes.

Retraction. rhBNP therapy can improve clinical outcomes and reduce in-hospital mortality compared with dobutamine in heart failure patients: a meta-analysis

AIMS

A meta-analysis was performed to compare the therapeutic outcomes in patients treated for heart failure (HF) with recombinant human brain natriuretic peptide (rhBNP) and dobutamine.

METHODS

PubMed, Embase and the Chinese Biomedical Database were exhaustively searched to identify studies relevant to this meta-analysis. Eight cohort studies were found suitable for inclusion. Data regarding trial validity, methodological processes and clinical outcomes were extracted.

RESULTS

Patients treated with rhBNP showed statistically significant reduction of in-hospital mortality and re-admission rates compared with the dobutamine treated patient group (both P < 0.05). Further, the rhBNP treated patient group showed higher survival outcomes, compared with dobutamine treated patients, when the post-treatment follow-up period was longer than 6 months (P < 0.05). Stratified analysis based on ethnicity showed a dramatic decrease of in-hospital mortality among mixed race HF patients receiving rhBNP treatment (P < 0.05), but such decreases were not statistically significant in Asian and Caucasian populations (both P > 0.05). On the other hand, re-admission rates were significantly lower in rhBNP treated Caucasian and mixed race populations (both P < 0.05). Notably, in rhBNP treated group, dose levels of 0.015 and 0.03 incrementally lowered the re-admission rates, displaying dose effect, and the re-admission rates at both rhBNP doses were significantly lower than the dobutamine treated group (both P < 0.05).

CONCLUSIONS

Our meta-analysis results suggested that rhBNP therapy is associated with lower in-hospital mortality and re-admission rates in HF patients compared to the dobutamine regimen. Nevertheless, large scale prospective, randomized trials are necessary to confirm these findings.

Mineralocorticoid Receptor Antagonism in Acute Heart Failure

OPINION STATEMENT

Heart failure (HF) remains a tremendous burden to health care systems and patients worldwide. The cornerstone neurohormonal disruption that leads to the debilitating sequelae in HF patients revolves primarily around aldosterone and the renin-angiotensin-aldosterone system (RAAS). Aldosterone plays a detrimental role in tissue remodeling by inducing inflammation and fibrosis within the cardiovascular and renal systems, leaving mineralocorticoid receptor antagonists (MRAs) as key pharmacological tools to slow pathogenesis and improve patient outcomes. The role of MRA in improving morbidity and mortality in outpatients with chronic HF and low ejection fraction is well established and supported by large randomized controlled trials. However, evidence-based data relating to the use of MRA in acute HF (AHF) remain somewhat limited, and therefore, the use of MRA is not ubiquitously considered in the acute setting. Current studies for the use of MRA in AHF are limited by small sample size as well as safety concerns relating to the dose-dependent effects on electrolyte homeostasis and renal function. Here, we discuss the imperative need for additional trials elucidating the potential benefits of MRA in AHF as an adjunct diuretic therapy. We not only discuss the role of MRA in neurohormonal regulation of aldosterone but also highlight a potential dose-dependent role for MRA in natriuresis. Furthermore, we showcase existing and recent evidence-based data demonstrating the effectiveness of MRA in AHF and on long-term outcomes. Finally, we look at several treatment strategies and safety concerns as they relate to MRA use so as to aid in avoidance of MRA-related complications while facilitating achievement of treatment goals.

Cardiovascular biology of the incretin system

Glucagon-like peptide-1 (GLP-1) is an incretin hormone that enhances glucose-stimulated insulin secretion and exerts direct and indirect actions on the cardiovascular system. GLP-1 and its related incretin hormone, glucose-dependent insulinotropic polypeptide, are rapidly inactivated by the enzyme dipeptidyl peptidase 4 (DPP-4), a key determinant of incretin bioactivity. Two classes of medications that enhance incretin action, GLP-1 receptor (GLP-1R) agonists and DPP-4 inhibitors, are used for the treatment of type 2 diabetes mellitus. We review herein the cardiovascular biology of GLP-1R agonists and DPP-4 inhibitors, including direct and indirect effects on cardiomyocytes, blood vessels, adipocytes, the control of blood pressure, and postprandial lipoprotein secretion. Both GLP-1R activation and DPP-4 inhibition exert multiple cardioprotective actions in preclinical models of cardiovascular dysfunction, and short-term studies in human subjects appear to demonstrate modest yet beneficial actions on cardiac function in subjects with ischemic heart disease. Incretin-based agents control body weight, improve glycemic control with a low risk of hypoglycemia, decrease blood pressure, inhibit the secretion of intestinal chylomicrons, and reduce inflammation in preclinical studies. Nevertheless, there is limited information on the cardiovascular actions of these agents in patients with diabetes and established cardiovascular disease. Hence, a more complete understanding of the cardiovascular risk to benefit ratio of incretin-based therapies will require completion of long-term cardiovascular outcome studies currently underway in patients with type 2 diabetes mellitus.