Effects of sacubitril/valsartan on neprilysin targets and the metabolism of natriuretic peptides in chronic heart failure: a mechanistic clinical study

Unraveling the Cardiac Matrix: From Diabetes to Heart Failure, Exploring Pathways and Potential Medications

Myocardial infarction (MI) often leads to heart failure (HF) through acute or chronic maladaptive remodeling processes. This establishes coronary artery disease (CAD) and HF as significant contributors to cardiovascular illness and death. Therefore, treatment strategies for patients with CAD primarily focus on preventing MI and lessening the impact of HF after an MI event. Myocardial fibrosis, characterized by abnormal extracellular matrix (ECM) deposition, is central to cardiac remodeling. Understanding these processes is key to identifying new treatment targets. Recent studies highlight SGLT2 inhibitors (SGLT2i) and GLP-1 receptor agonists (GLP1-RAs) as favorable options in managing type 2 diabetes due to their low hypoglycemic risk and cardiovascular benefits. This review explores inflammation's role in cardiac fibrosis and evaluates emerging anti-diabetic medications' effectiveness, such as SGLT2i, GLP1-RAs, and dipeptidyl peptidase-4 inhibitors (DPP4i), in preventing fibrosis in patients with diabetes post-acute MI. Recent studies were analyzed to identify effective medications in reducing fibrosis risk in these patients. By addressing these areas, we can advance our understanding of the potential benefits of anti-diabetic medications in reducing cardiac fibrosis post-MI and improve patient outcomes in individuals with diabetes at risk of HF.

Evaluation of a New NT-proBNP Immunoassay on an Automated Core Laboratory System

BACKGROUND

Heart failure remains a major cause of morbidity and mortality despite improvements in treatment. This study aimed to evaluate the Alere N-terminal pro B-type natriuretic peptide (NT-proBNP) immunoassay on the Abbott Alinity i platform.

METHODS

The analytical performance including precision, linearity, limit of quantitation (LOQ), carryover, dilution-recovery, and stability was evaluated. A method comparison between the Abbott Alere NT-proBNP assay and Roche Elecsys proBNP II assay was performed using 70 residual plasma samples.

RESULTS

Total imprecision was 4.1%, 3.5%, and 2.3% for low (120.9 ng/L), medium (333.9 ng/L), and high (4767.4 ng/L) QC levels, respectively. The manufacturer's claimed LOQ of 8.3 ng/L was verified. Method comparison between the Alere NT-proBNP assay and the Elecsys proBNP II assay showed good agreement between assays with an R value of 0.998, a slope of 1.05 (95% CI, 1.03-1.06), and an intercept of 45.81 (95% CI, -46.6.84 to 138.22). The Bland-Altman plot showed an absolute bias of 250 ng/L or 6.02%. Subrange analysis (NT-proBNP <2000 ng/L) showed good agreement with an R value of 0.998, a slope of 1.04 (95% CI, 1.02-1.06), and an intercept of -4.83 (95% CI, -26.95 to 17.28), with a mean bias of 26 ng/L or 3.2%. The stability of NT-proBNP was also verified in lithium heparin plasma samples stored at 4°C over a 7-day period. Hemolysis and lipemia interference thresholds were verified, but icterus impacted NT-proBNP recovery by >20% at low analyte concentrations.

CONCLUSIONS

The Alere NT-proBNP assay demonstrated acceptable analytical performance and very good clinical concordance with the Elecsys proBNP II assay.

The multidimensional value of natriuretic peptides in heart failure, integrating laboratory and clinical aspects

Natriuretic peptides (NP) play an essential role in heart failure (HF) regulation, and their measurement has improved diagnostic and prognostic accuracy. Clinical symptoms and objective measurements, such as NP levels, should be included in the HF definition to render it more reliable and consistent among observers, hospitals, and healthcare systems. BNP and NT-proBNP are reasonable surrogates for cardiac disease, and their measurement is critical to early diagnosis and risk stratification of HF patients. NPs should be measured in all patients presenting with dyspnea or other symptoms suggestive of HF to facilitate early diagnosis and risk stratification. Both BNP and NT-proBNP are currently used for guided HF management and display comparable diagnostic and prognostic accuracy. Standardized cutoffs for each NP assay are essential for data comparison. The value of NP testing is recognized at various levels, including patient empowerment and education, analytical and operational issues, clinical HF management, and cost-effectiveness.

Proteomic Associations of NT-proBNP (N-Terminal Pro-B-Type Natriuretic Peptide) in Heart Failure With Preserved Ejection Fraction

BACKGROUND

NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels are variably elevated in heart failure with preserved ejection fraction (HFpEF), even in the presence of increased left ventricular filling pressures. NT-proBNP levels are prognostic in HFpEF and have been used as an inclusion criterion for several recent randomized clinical trials. However, the underlying biologic differences between HFpEF participants with high and low NT-proBNP levels remain to be fully understood.

METHODS

We measured 4928 proteins using an aptamer-based proteomic assay (SOMAScan) in available plasma samples from 2 cohorts: (1) Participants with HFpEF enrolled in the PHFS (Penn Heart Failure Study; n=253); (2) TOPCAT (Treatment of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist Trial) participants in the Americas (n=218). We assessed the relationship between SOMAScan-derived plasma NT-proBNP and levels of other proteins available in the SOMAScan assay version 4 using robust linear regression, with correction for multiple comparisons, followed by pathway analysis.

RESULTS

NT-proBNP levels exhibited prominent proteome-wide associations in PHFS and TOPCAT cohorts. Proteins most strongly associated with NT-proBNP in both cohorts included SVEP1 (sushi, von Willebrand factor type-A, epidermal growth factor, and pentraxin domain containing 1; βTOPCAT=0.539; P<0.0001; βPHFS=0.516; P<0.0001) and ANGPT2 (angiopoietin 2; βTOPCAT=0.571; P<0.0001; βPHFS=0.459; P<0.0001). Canonical pathway analysis demonstrated consistent associations with multiple pathways related to fibrosis and inflammation. These included hepatic fibrosis and inhibition of matrix metalloproteases. Analyses using cut points corresponding to estimated quantitative concentrations of 360 pg/mL (and 480 pg/mL in atrial fibrillation) revealed similar proteomic associations.

CONCLUSIONS

Circulating NT-proBNP levels exhibit prominent proteomic associations in HFpEF. Our findings suggest that higher NT-proBNP levels in HFpEF are a marker of fibrosis and inflammation. These findings will aid the interpretation of NT-proBNP levels in HFpEF and may guide the selection of participants in future HFpEF clinical trials.

Impact of sacubitril/valsartan on cardiac and systemic hypoxia in chronic heart failure

In heart failure patients with reduced ejection fraction, Sacubitril/valsartan (S/V) increased proBNP T71 glycosylation, which is regulated negatively by hypoxia via miR-30a in vitro. Using a cohort of 73 HFrEF patients who were transitioned from standard HF medication to S/V, we found that the increase in proBNP T71 glycosylation after S/V was associated with a decrease in cardiac hypoxia. We further found that plasma levels of K709-acteylated HIF1α, HIF-regulated and HIF-independent biomarkers also evolved consistently with a decrease in hypoxia. We further confirmed that biomarker changes were related to hypoxia, in a rat model subjected to isobaric hypoxia. We measured them in rats subjected to isobaric hypoxia. Overall, these data strongly suggest that optimally treated HFrEF patients exhibited subclinical hypoxia that is improved by S/V. The data also posit proBNP T71 glycosylation as a biomarker of cardiac hypoxia.

Neprilysin inhibitors and risk of Alzheimer's disease: A future perspective

Alzheimer's disease (AD) is a heterogeneous neurodegenerative disease with multifaceted neuropathological disorders. AD is characterized by intracellular accumulation of phosphorylated tau proteins and extracellular deposition of amyloid beta (Aβ). Various protease enzymes, including neprilysin (NEP), are concerned with the degradation and clearance of Aβ. Indeed, a defective neuronal clearance pathway due to the dysfunction of degradation enzymes might be a possible mechanism for the accumulation of Aβ and subsequent progression of AD neuropathology. NEP is one of the most imperative metalloproteinase enzymes involved in the clearance of Aβ. This review aimed to highlight the possible role of NEP inhibitors in AD. The combination of sacubitril and valsartan which is called angiotensin receptor blocker and NEP inhibitor (ARNI) may produce beneficial and deleterious effects on AD neuropathology. NEP inhibitors might increase the risk of AD by the inhibition of Aβ clearance, and increase brain bradykinin (BK) and natriuretic peptides (NPs), which augment the pathogenesis of AD. These verdicts come from animal model studies, though they may not be applied to humans. However, clinical studies revealed promising safety findings regarding the use of ARNI. Moreover, NEP inhibition increases various neuroprotective peptides involved in inflammation, glucose homeostasis and nerve conduction. Also, NEP inhibitors may inhibit dipeptidyl peptidase 4 (DPP4) expression, ameliorating insulin and glucagon-like peptide 1 (GLP-1) levels. These findings proposed that NEP inhibitors may have a protective effect against AD development by increasing GLP-1, neuropeptide Y (NPY) and substance P, and deleterious effects by increasing brain BK. Preclinical and clinical studies are recommended in this regard.

Does Speckle Tracking Transthoracic Echocardiography Indicate Subtle Changes in Left Ventricular Function in Heart Failure Patients with Reduced Ejection Fraction Treated by Sacubitril-valsartan?

Background

In heart failure patients and reduced ejection fraction (HFrEF), assessing subtle changes in left ventricle (LV) function is crucial for monitoring treatment efficacy. This study aims to determine the effect of valsartan/sacubitril on LV ejection fraction (EF) assessed by two-dimensional (2D) transthoracic echocardiography (TTE) in comparison to that assessed by 2D TTE speckle tracking in patients with HFrEF ≤35% after 6 months of treatment.

Patients and Methods

A prospective study will be conducted on 200 heart failure patients with reduced EF (HFrEF) undergoing sacubitril-valsartan treatment. Each participant underwent a comprehensive evaluation, including physical examination, history taking, serial 12-lead electrocardiogram, and 2D echo to evaluate cardiac parameters. In addition, 2D speckle tracking echocardiography (STE) assessments were conducted before and after 6 months of valsartan/sacubitril treatment.

Results

The enrolled patients had an average age of 48 years with 63% females. At the beginning of the study, 9 (4.5%) patients were classified as New York Heart Association (NYHA) FC I, 120 (60%) as NYHA FC II, 64 (32%) as NYHA FC III, and 7 (3.5%) as FC IV. Following treatment, 82 (41%) patients improved to NYHA FC I, and 118 (59%) were in NYHA FC II. Notably, 82 (41%) patients showed improved left ventricular EF (LVEF), detected either by traditional TTE or STE, whereas 118 (59%) showed no improvement in EF through traditional TTE. In addition, 74 (37%) patients demonstrated improvement detected by STE. In contrast, 44 (22%) patients demonstrated no improvement in EF detected by either TTE or STE.

Conclusion

STE was a more reliable diagnostic method for seeing early LVEF improvement in patients with HFrEF receiving valsartan/sacubitril treatment not seen by conventional TTE.

Longitudinal Changes in Natriuretic Peptides and Reverse Cardiac Remodeling in Patients with Heart Failure Treated with Sacubitril/Valsartan Across the Left Ventricular Ejection Traction Spectrum

Sacubitril/valsartan improves outcomes in patients with heart failure (HF) with reduced ejection fraction. However, the relationship between longitudinal changes in natriuretic peptides and echocardiographic parameters in patients with HF treated with sacubitril/valsartan across the left ventricular ejection fraction (LVEF) range is not fully understood.In patients with HF treated with sacubitril/valsartan, comprehensive data on natriuretic peptides, including atrial natriuretic peptide (ANP), N-terminal pro-brain-type natriuretic peptide (NT-proBNP), BNP, and echocardiography, were measured after 6 months of treatment. We assessed the change in natriuretic peptides and echocardiographic parameters in LVEF classification subgroups.Among 49 patients, the median ANP concentration increased from 55 pg/mL at baseline to 78 pg/mL (P < 0.001). The NT-proBNP concentration decreased from 250 pg/mL to 146 pg/mL (P < 0.001). No significant change was observed in the BNP concentration (P = 0.640). The trajectories of each natriuretic peptide in patients with LVEF > 40% (n = 22) were similar to those in individuals with LVEF ≤ 40% (n = 27). Regardless of LVEF classification, echocardiography at 6 months showed a significant improvement in LVEF, left ventricular end-diastolic volume, and the ratio of early diastolic mitral inflow velocity to early diastolic mitral annulus velocity (E/e'). The reduction in natriuretic peptide concentration was related to LV reverse remodeling and decreased left and right atrial pressures assessed by E/e' and inferior vena cava diameter.Sacubitril/valsartan induced an increase in ANP, a reduction in NT-proBNP, and no change in plasma BNP, regardless of LVEF. It caused LV reverse remodeling, and the natriuretic peptide concentration changes were associated with structural and functional echocardiographic parameters.

Neprilysin activity is increased in metabolic dysfunction-associated steatotic liver disease and normalizes after bariatric surgery or GLP-1 therapy

Inhibitors of neprilysin improve glycemia in patients with heart failure and type 2 diabetes (T2D). The effect of weight loss by diet, surgery, or pharmacotherapy on neprilysin activity (NEPa) is unknown. We investigated circulating NEPa and neprilysin protein concentrations in obesity, T2D, metabolic dysfunction-associated steatotic liver disease (MASLD), and following bariatric surgery, or GLP-1-receptor-agonist therapy. NEPa, but not neprilysin protein, was enhanced in obesity, T2D, and MASLD. Notably, MASLD associated with NEPa independently of BMI and HbA1c. NEPa decreased after bariatric surgery with a concurrent increase in OGTT-stimulated GLP-1. Diet-induced weight loss did not affect NEPa, but individuals randomized to 52-week weight maintenance with liraglutide (1.2 mg/day) decreased NEPa, consistent with another study following 6-week liraglutide (3 mg/day). A 90-min GLP-1 infusion did not alter NEPa. Thus, MASLD may drive exaggerated NEPa, and lowered NEPa following bariatric surgery or liraglutide therapy may contribute to the reported improved cardiometabolic effects.

Neprilysin deficiency reduces hepatic gluconeogenesis in high fat-fed mice

Neprilysin is a peptidase that cleaves glucoregulatory peptides, including glucagon-like peptide-1 (GLP-1) and cholecystokinin (CCK). Some studies suggest that its inhibition in diabetes and/or obesity improves glycemia, and that this is associated with enhanced insulin secretion, glucose tolerance and insulin sensitivity. Whether reduced neprilysin activity also improves hepatic glucose metabolism has not been explored. We sought to determine whether genetic deletion of neprilysin suppresses hepatic glucose production (HGP) in high fat-fed mice. Nep+/+ and Nep-/- mice were fed high fat diet for 16 weeks, and then underwent a pyruvate tolerance test (PTT) to assess hepatic gluconeogenesis. Since glycogen breakdown in liver can also yield glucose, we assessed liver glycogen content in fasted and fed mice. In Nep-/- mice, glucose excursion during the PTT was reduced when compared to Nep+/+ mice. Further, liver glycogen levels were significantly greater in fasted but not fed Nep-/- versus Nep+/+ mice. Since gut-derived factors modulate HGP, we tested whether gut-selective inhibition of neprilysin could recapitulate the suppression of hepatic gluconeogenesis observed with whole-body inhibition, and this was indeed the case. Finally, the gut-derived neprilysin substrates, GLP-1 and CCK, are well-known to suppress HGP. Having previously demonstrated elevated plasma GLP-1 levels in Nep-/- mice, we now measured plasma CCK bioactivity and reveal an increase in Nep-/- versus Nep+/+ mice, suggesting GLP-1 and/or CCK may play a role in reducing HGP under conditions of neprilysin deficiency. In sum, neprilysin modulates hepatic gluconeogenesis and strategies to inhibit its activity may reduce HGP in type 2 diabetes and obesity.

Prevalent and Incident Anemia in PARADIGM-HF and the Effect of Sacubitril/Valsartan

BACKGROUND

Anemia is common in patients with heart failure with reduced ejection fraction and is associated with poor clinical outcomes. Renin-angiotensin system blockers lower hemoglobin and may induce anemia.

OBJECTIVES

The authors investigated whether concomitant neprilysin inhibition might ameliorate this effect of renin-angiotensin system blockers in PARADIGM-HF (Prospective comparison of ARNI with ACEI to Determine Impact on Global Mortality and morbidity in Heart Failure).

METHODS

Anemia was defined as hemoglobin <120 g/L in women and <130 g/L in men at screening. The authors investigated the effect of randomized treatment on clinical outcomes according to anemia status, change in hemoglobin from baseline, and the incidence of anemia.

RESULTS

Of 8,239 participants with a baseline hemoglobin measurement, 1,677 (20.4%) were anemic. Patients with anemia had a more severe heart failure profile, worse kidney function, greater neurohormonal derangement, and worse clinical outcomes. Sacubitril/valsartan, compared with enalapril, decreased the risk of cardiovascular death or heart failure hospitalization similarly in patients with (HR: 0.84; 95% CI: 0.71-1.00) and without anemia (HR: 0.78 [95% CI: 0.71-0.87]; P value for interaction = 0.478). Between baseline and 12 months, hemoglobin decreased by 1.5 g/L (95% CI: 1.2-1.7 g/L) with sacubitril/valsartan compared with 2.3 g/L (95% CI: 2.0-2.6 g/L) with enalapril: mean difference 0.8 g/L (95% CI: 0.5-1.2 g/L; P < 0.001). Patients assigned to sacubitril/valsartan were less likely to develop anemia at 12 months (321 of 2,806 [11.4%]) compared with patients randomized to enalapril (440 of 2,824 [15.6%]) (OR: 0.70 [95% CI: 0.60-0.81]; P < 0.001). These findings were similar in PARAGON-HF (Prospective Comparison of ARNI with ARB Global Outcomes in HF with Preserved Ejection Fraction) (sacubitril/valsartan vs valsartan). There was biomarker evidence of increased iron utilization with sacubitril/valsartan.

CONCLUSIONS

Irrespective of anemia status, sacubitril/valsartan compared with enalapril, decreased mortality and hospitalization. Hemoglobin decreased less with sacubitril/valsartan and the incidence of new anemia was lower with sacubitril/valsartan. (Prospective comparison of ARNI with ACEI to Determine Impact on Global Mortality and morbidity in Heart Failure [PARADIGM-HF] trial; NCT01035255).

Atrial natriuretic peptide stimulates autophagy/mitophagy and improves mitochondrial function in chronic heart failure

Mitochondrial dysfunction, causing increased reactive oxygen species (ROS) production, is a molecular feature of heart failure (HF). A defective antioxidant response and mitophagic flux were reported in circulating leucocytes of patients with chronic HF and reduced ejection fraction (HFrEF). Atrial natriuretic peptide (ANP) exerts many cardiac beneficial effects, including the ability to protect cardiomyocytes by promoting autophagy. We tested the impact of ANP on autophagy/mitophagy, altered mitochondrial structure and function and increased oxidative stress in HFrEF patients by both ex vivo and in vivo approaches. The ex vivo study included thirteen HFrEF patients whose peripheral blood mononuclear cells (PBMCs) were isolated and treated with αANP (10^-11 M) for 4 h. The in vivo study included six HFrEF patients who received sacubitril/valsartan for two months. PBMCs were characterized before and after treatment. Both approaches analyzed mitochondrial structure and functionality. We found that levels of αANP increased upon sacubitril/valsartan, whereas levels of NT-proBNP decreased. Both the ex vivo direct exposure to αANP and the higher αANP level upon in vivo treatment with sacubitril/valsartan caused: (i) improvement of mitochondrial membrane potential; (ii) stimulation of the autophagic process; (iii) significant reduction of mitochondrial mass-index of mitophagy stimulation-and upregulation of mitophagy-related genes; (iv) reduction of mitochondrial damage with increased inner mitochondrial membrane (IMM)/outer mitochondrial membrane (OMM) index and reduced ROS generation. Herein we demonstrate that αANP stimulates both autophagy and mitophagy responses, counteracts mitochondrial dysfunction, and damages ultimately reducing mitochondrial oxidative stress generation in PBMCs from chronic HF patients. These properties were confirmed upon sacubitril/valsartan administration, a pivotal drug in HFrEF treatment.

Atrial Natriuretic Peptides as a Bridge between Atrial Fibrillation, Heart Failure, and Amyloidosis of the Atria

ANP is mainly synthesized by the atria, and upon excretion, it serves two primary purposes: vasodilation and increasing the renal excretion of sodium and water. The understanding of ANP's role in cardiac systems has improved considerably in recent decades. This review focuses on several studies demonstrating the importance of analyzing the regulations between the endocrine and mechanical function of the heart and emphasizes the effect of ANP, as the primary hormone of the atria, on atrial fibrillation (AF) and related diseases. The review first discusses the available data on the diagnostic and therapeutic applications of ANP and then explains effect of ANP on heart failure (HF) and atrial fibrillation (AF) and vice versa, where tracking ANP levels could lead to understanding the pathophysiological mechanisms operating in these diseases. Second, it focuses on conventional treatments for AF, such as cardioversion and catheter ablation, and their effects on cardiac endocrine and mechanical function. Finally, it provides a point of view about the delayed recovery of cardiac mechanical and endocrine function after cardioversion, which can contribute to the occurrence of acute heart failure, and the potential impact of restoration of the sinus rhythm by extensive ablation or surgery in losing ANP-producing sites. Overall, ANP plays a key role in heart failure through its effects on vasodilation and natriuresis, leading to a decrease in the activity of the renin-angiotensin-aldosterone system, but it is crucial to understand the intimate role of ANP in HF and AF to improve their diagnosis and personalizing the patients' treatment.

Association between the NEP rs701109 polymorphism and the clinical efficacy and safety of sacubitril/valsartan in Chinese patients with heart failure

OBJECTIVE

Sacubitril/valsartan is a commonly used medicine for treating heart failure (HF) patients, but the treatment effects significantly vary. Neprilysin (NEP) and carboxylesterase 1 (CES1) play an important role in the efficacy of sacubitril/valsartan. The purpose of this study was to explore the relationship between NEP and CES1 gene polymorphisms and the efficacy and safety of sacubitril/valsartan treatment in HF patients.

METHODS

Genotyping of 10 single nucleotide polymorphisms (SNPs) of the NEP and CES1 genes in 116 HF patients was performed by the Sequenom MassARRAY method, and logistic regression and haplotype analysis were used to evaluate the associations between SNPs and the clinical efficacy and safety of sacubitril/valsartan in HF patients.

RESULTS

A total of 116 Chinese patients with HF completed the whole trial, and T variations in rs701109 in NEP gene were an independent risk factor (P = 0.013, OR = 3.292, 95% CI:1.287-8.422) for the clinical efficacy of sacubitril/valsartan. Furthermore, haplotype analysis of 6 NEP SNPs (including rs701109) was performed and showed that the CGTACC and TGTACC haplotypes were significantly associated with clinical efficacy (OR = 0.095, 95%CI: 0.012-0.723, P = 0.003; OR = 5.586, 95% CI: 1.621-19.248, P = 0.005). Moreover, no association was found between SNPs of other selected genes in terms of efficacy in HF patients, and no association was observed between SNPs and symptomatic hypotension.

CONCLUSION

Our results suggest an association between rs701109 and sacubitril/valsartan response in HF patients. Symptomatic hypotension is not associated with the presence of NEP polymorphisms.

Deconvolution of BNP and NT-proBNP Immunoreactivities by Mass Spectrometry in Heart Failure and Sacubitril/Valsartan Treatment

BACKGROUND

Elevated BNP and the N-terminal fragment of the proBNP (NT-proBNP) are hallmarks of heart failure (HF). Generally, both biomarkers parallel each other. In patients receiving sacubitril/valsartan, BNP remained stable while NT-proBNP decreased. As BNP and NT-proBNP assays have limited specificity due to cross-reactivity, we quantified by mass spectrometry (MS) the contributing molecular species.

METHODS

We included 356 healthy volunteers, 100 patients with acute dyspnoea (49 acute decompensated HF; 51 dyspnoea of non-cardiac origin), and 73 patients with chronic HF and reduced ejection fraction treated with sacubitril/valsartan. BNP and NT-proBNP immunoreactivities (BNPir and NT-proBNPir) were measured by immunoassays (Abbott ARCHITECT and Roche Diagnostics proBNPII) and proBNP-derived peptides and glycosylation at serine 44 by MS on plasma samples.

RESULTS

BNPir corresponded to the sum of proBNP1-108, BNP1-32, BNP3-32, and BNP5-32 (R2 = 0.9995), while NT-proBNPir corresponded to proBNP1-108 and NT-proBNP1-76 not glycosylated at serine 44 (R2 = 0.992). NT-proBNPir was better correlated (R2 = 0.9597) than BNPir (R2 = 0.7643) with proBNP signal peptide (a surrogate of proBNP production). In patients receiving sacubitril/valsartan, non-glycosylated NT-proBNP1-76 remained constant (P = 0.84) despite an increase in NT-proBNP1-76 and its glycosylation (P < 0.0001). ProBNP1-108 remained constant (P = 0.12) while its glycosylation increased (P < 0.0001), resulting in a decrease in non-glycosylated proBNP1-108 (P < 0.0001), and in NT-proBNPir.

CONCLUSIONS

Glycosylation interfered with NT-proBNPir measurement, explaining the discrepant evolution of these 2 biomarkers in patients receiving sacubitril/valsartan. Both BNPir and NT-proBNPir are surrogates of proBNP1-108 production, NT-proBNPir being more robust in the clinical contexts studied.

Effects of switching from sacubitril/valsartan to valsartan alone on plasma levels of natriuretic peptides and myocardial remodeling in heart failure with reduced ejection fraction

BACKGROUND

We examined the effect of switching from angiotensin receptor-neprilysin inhibitor (ARNI) to angiotensin-receptor blocker (ARB) on plasma levels of natriuretic peptides and myocardial remodeling.

METHODS

This is a prospective study that included 11 patients with heart failure (HF) treated with ARNI. The patients were divided into two groups: 5 patients who continued treatment with sacubitril/valsartan 194/206 mg/day (ARNI-continue group) and 6 patients who were switched to valsartan 160 mg/day (ARB-switch group). The primary endpoint was percent change (%Change) in plasma A-, B-, and N-terminal pro-B-type natriuretic peptide (ANP, BNP, and NT-proBNP) levels from the baseline to week 24. The secondary endpoint was the change in echocardiographic parameters related to myocardial remodeling from the baseline to week 24.

RESULTS

ANP levels in the ARB-switch group significantly decreased (from 1155.7 ± 592.6 pg/mL to 231.6 ± 233.8 pg/mL, p = 0.035), whereas those in the ARNI-continue group were not significant (p = 0.180). The %Change of decrease in ANP levels was significantly greater in the ARB-switch group than the ARNI-continue group (- 76.9% vs. -9.1%, p = 0.009). BNP levels were not significantly different between the baseline and week 24 in both groups. NT-proBNP levels in the ARB-switch group increased from 1185.3 ± 835.6 pg/mL to 1515.2 ± 1213.5 pg/mL, although the changes were not statistically significant (p = 0.345). The %Change of increase in NT-proBNP levels was significantly greater in the ARB-switch group than the ARNI-continue group (57.9% vs. 17.3%, p = 0.016). In the ARB-switch group, there was a significant increase in left ventricular (LV) end-systolic volume (from 41.3 ± 24.1 mL/m2 to 71.4 ± 8.8 mL/m2, p = 0.043) and LV peak-systolic wall stress (from 187.0 ± 42.7 × 103 dynes/cm2 to 279.7 ± 34.1 × 103 dynes/cm2, p = 0.012) from the baseline to week 24 and a trend toward a decrease in LV ejection fraction (p = 0.080). In the ARNI-continue group, no differences in echocardiographic parameters were observed from the baseline to week 24.

CONCLUSION

Switching from ARNI to ARB may worsen HF due to returning to myocardial remodeling induced by a sustained decline in ANP levels.

Effect of sacubitril/valsartan on natriuretic peptide in patients with compensated heart failure

The time-dependent changes in the natriuretic peptide families during sacubitril/valsartan (S/V) treatment remain obscure in the Asian heart failure (HF) cohort. Eighty-one outpatients with compensated HF were analyzed. The patients were divided into two groups based on the administration of S/V (n = 42) or angiotensin converting enzyme inhibitor (ACE-I; n = 39). Changes to the natriuretic peptide families and the daily dose of loop diuretics were evaluated 3 and 6 months after the intervention. The atrial natriuretic peptide (ANP) level was significantly increased (102 [63-160] pg/mL to 283 [171-614] pg/mL [3 months]; 409 [210-726] pg/mL [6 months]) in the S/V group but not in the ACE-I group. The dose of furosemide was significantly decreased during the six-month follow-up period in the S/V group (40 [20-40] mg to 20 [10-20] mg) but not in the ACE-I group. A multivariate logistic regression model showed that the presence of persistent atrial fibrillation (AF) and HF with a preserved left ventricular ejection fraction (HFpEF) was independently associated with a high delta-ANP ratio (≥ 4.5 ANP value on the start date/ANP value at 6 months; the mean value was used as the cutoff value) (odds ratio [OR]: 4.649, 95% CI 1.032-20.952 and OR: 7.558, 95% CI 1.427-40.042). The plasma level of ANP was increased, and the loop diuretic dose was decreased by the addition of neprilysin inhibitor therapy in patients with compensated HF. In patients with HFpEF and complicated persistent AF, neprilysin inhibitor therapy was associated with an increase in ANP.

The Predictive Value of A, B, and C-Type Natriuretic Peptides in People at Risk of Heart Disease: Protocol for a Longitudinal Observational Study

BACKGROUND

Heart disease and stroke are major and often unheralded causes of serious morbidity and premature death in middle age. Early detection of those most at risk is an urgent unmet need for instituting preventative measures. In an earlier community study (Canterbury Health, Ageing and Life Course [CHALICE]) of healthy people aged 50 years, contrary to previous reports, low levels of the heart hormone B-type natriuretic peptide (BNP) were associated with reduced measures of heart function and higher markers of vascular risk. A specific gene variant (rs198358) was found to be an independent contributor to higher BNP levels. A closely related vascular hormone (C-type natriuretic peptide [CNP]) showed opposite associations-higher levels were correlated with higher vascular risk and reduced cardiac function. To determine whether these novel findings predict serious heart or vascular disease in later life, this proposal re-examines the same CHALICE participants 15 years later.

OBJECTIVE

The primary objective is to determine the predictive value of (1) low plasma concentrations of the circulating cardiac hormones (atrial natriuretic peptide [ANP] and BNP) and (2) high levels of the vascular hormone CNP at age 50 years in detecting impaired cardiac and vascular function 15 years later. Secondary objectives are to determine specific associations of individual analytes (ANP, BNP, CNP, cyclic guanosine monophosphate [cGMP]) with echo-derived changes in cardiac performance at ages 50 years and 65 years.

METHODS

All of the 348 participants (205/348, 58.9% female; 53/348, 15.2% Māori or Pacifica ethnicity) participating in the original CHALICE study-free of history of heart or renal disease at age 50 years and who consented to further study-will be contacted, recruited, and restudied as previously described. Data will include intervening health history, physical examination, heart function (speckle-tracking echocardiography), vascular status (carotid intimal thickness), and genetic status (genome-wide genotyping). Laboratory measures will include fasting blood sampling and routine biochemistry, ANP, BNP, CNP, their downstream effector (cGMP), and their bio-inactive products. Humoral metabolic-cardiovascular risk factors will be measured after an overnight fast. Primary outcomes will be analyzed using multiple linear regression.

RESULTS

The study will commence in 2022 and be completed in 2024.

CONCLUSIONS

Proving our hypothesis-that low BNP and high CNP at any age in healthy people predict premature aging of heart and blood vessels, respectively-opens the way to early detection and improved outcomes for those most at risk. Confirmation of our hypotheses would improve current methods of screening and, in appropriate cases, enable interventions aimed at increasing natriuretic hormones and reducing risk of serious cardiovascular complications using drugs already available. Such advances in detection, and from interventional corrections, have the potential to not only improve health in the community but also reduce the high costs inevitably associated with heart failure.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/37011.

Vericiguat in Heart Failure: Characteristics, Scientific Evidence and Potential Clinical Applications

Despite recent advances in heart failure (HF) management, the risk of death and hospitalizations remains high in the long term. HF is characterized by endothelial dysfunction, inflammation and increased oxidative stress, due to a reduction in the activity of the nitric oxide (NO)-soluble guanylate cyclase (sGC)-cyclic guanosine monophosphate (cGMP) signaling pathway. All these factors contribute to direct damage at the myocardial, vascular and renal level. Vericiguat restores the deficiency in this signaling pathway, through stimulation and activation of sGC, aiming to increase cGMP levels, with a reduction in HF-related oxidative stress and endothelial dysfunction. Two main clinical trials were developed in this setting: the SOCRATES-REDUCED phase II study and the VICTORIA phase III study. They found that vericiguat is safe, well tolerated and effective with an absolute event-rate reduction in patients affected by HF with reduced ejection fraction (HFrEF) and recent cardiac decompensation. In patients with HF with preserved ejection fraction (HfpEF), the SOCRATES-PRESERVED trial demonstrated an improvement in quality of life and health status, but the proven beneficial effects with vericiguat are still limited. Further studies are needed to correctly define the role of this drug in heart failure syndromes. Our paper reviews the potential applications and pharmacological characteristics of vericiguat in HFrEF and HFpEF.

Progress and prospects of Sacubitril/Valsartan: Based on heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is present in nearly half of patients with heart failure. The prevalence of heart failure with normal or near-normal ejection fractions increases more rapidly than in patients with reduced ejection fractions. Angiotensin-converting enzyme inhibitor (ACEI), angiotensin receptor blocker (ARB), aldosterone antagonist, β-blocker, and calcium channel blocker have not shown significant efficacy in HFpEF clinical trials. Sacubitril/Valsartan, combined angiotensin receptor blocker (Valsartan) with neprilysin inhibitor (Sacubitril), was the first-of-its-kind angiotensin receptor-neprilysin inhibitor (ARNI) to be developed. It has shown significant efficacy on HFpEF in recent studies. It is considered that most of the current Sacubitril/Valsartan studies are still concentrated in the field of heart failure, especially heart failure with reduced ejection fraction (HFrEF). This review discusses the latest advances in cardiovascular, renal, and metabolic aspects of Sacubitril/Valsartan, mainly in HFpEF, providing more evidence for further future research on Sacubitril/Valsartan and raising issues that should be paid attention. At the same time, this review will introduce the academic consensus on Sacubitril/Valsartan in treating HFpEF in China.

Molecular mechanisms of sacubitril/valsartan in cardiac remodeling

Cardiovascular diseases have become a major clinical burden globally. Heart failure is one of the diseases that commonly emanates from progressive uncontrolled hypertension. This gives rise to the need for a new treatment for the disease. Sacubitril/valsartan is a new drug combination that has been approved for patients with heart failure. This review aims to detail the mechanism of action for sacubitril/valsartan in cardiac remodeling, a cellular and molecular process that occurs during the development of heart failure. Accumulating evidence has unveiled the cardioprotective effects of sacubitril/valsartan on cellular and molecular modulation in cardiac remodeling, with recent large-scale randomized clinical trials confirming its supremacy over other traditional heart failure treatments. However, its molecular mechanism of action in cardiac remodeling remains obscure. Therefore, comprehending the molecular mechanism of action of sacubitril/valsartan could help future research to study the drug’s potential therapy to reduce the severity of heart failure.

The Effect of SGLT2 Inhibitor Dapagliflozin on Serum Levels of Apelin in T2DM Patients with Heart Failure

Apelin is a multifunctional peptide that plays a pivotal role in cardiac remodeling and HF manifestation because of counteracting angiotensin-II. We hypothesized that positive influence of sodium-glucose co-transporter-2 (SGLT2) inhibitor on cardiac function in T2DM patients with HF might be mediated by apelin and that its levels seem to be a target of management. A total of 153 type 2 diabetes mellitus (T2DM) patients with II/III HF NYHA class and average left ventricular (LV) ejection fraction (EF) of 46% have been enrolled and treated with dapagliflosin. The serum levels of apelin and N-terminal brain natriuretic pro-peptide (NT-proBNP) were measured at baseline and over a 6-month period of dapagliflosin administration. We noticed that administration of dapagliflozin was associated with a significant increase in apelin levels of up to 18.3% and a decrease in NT-proBNP of up to 41.0%. Multivariate logistic regression showed that relative changes of LVEF, LA volume index, and early diastolic blood filling to longitudinal strain ratio were strongly associated with the levels of apelin, whereas NT-proBNP exhibited a borderline significance in this matter. In conclusion, dapagiflosin exerted a positive impact on echocardiographic parameters in close association with an increase in serum apelin levels, which could be a surrogate target for HF management.

B-Type Natriuretic Peptide (BNP) Revisited—Is BNP Still a Biomarker for Heart Failure in the Angiotensin Receptor/Neprilysin Inhibitor Era?

Simple Summary

Active BNP-32, less active proBNP-108, and inactive N-terminal proBNP-76 all circulate in the blood. The circulating protease neprilysin has lower substrate specificity for BNP than ANP, while proBNP and N-terminal proBNP are not degraded by neprilysin. Currently available BNP immunoassays react with both mature BNP and proBNP; therefore, measured plasma BNP is mature BNP + proBNP. Because ARNI administration increases mature BNP, measured plasma BNP initially increases with ARNI administration by the amount of the increase in mature BNP. Later, ARNI administration reduces myocardial wall stress, and the resultant reduction in BNP production more than offsets the increase of mature BNP due to inhibition of degradation by neprilysin, resulting in lower plasma BNP levels. In the ARNI era, BNP remains a useful biomarker for heart failure, though mild increases early during ARNI administration should be taken into consideration.

Abstract

Myocardial wall stress, cytokines, hormones, and ischemia all stimulate B-type (or brain) natriuretic peptide (BNP) gene expression. Within the myocardium, ProBNP-108, a BNP precursor, undergoes glycosylation, after which a portion is cleaved by furin into mature BNP-32 and N-terminal proBNP-76, depending on the glycosylation status. As a result, active BNP, less active proBNP, and inactive N-terminal proBNP all circulate in the blood. There are three major pathways for BNP clearance: (1) cellular internalization via natriuretic peptide receptor (NPR)-A and NPR-C; (2) degradation by proteases in the blood, including neprilysin, dipeptidyl-peptidase-IV, insulin degrading enzyme, etc.; and (3) excretion in the urine. Because neprilysin has lower substrate specificity for BNP than atrial natriuretic peptide (ANP), the increase in plasma BNP after angiotensin receptor neprilysin inhibitor (ARNI) administration is much smaller than the increase in plasma ANP. Currently available BNP immunoassays react with both mature BNP and proBNP. Therefore, BNP measured with an immunoassay is mature BNP + proBNP. ARNI administration increases mature BNP but not proBNP, as the latter is not degraded by neprilysin. Consequently, measured plasma BNP initially increases with ARNI administration by the amount of the increase in mature BNP. Later, ARNI reduces myocardial wall stress, and the resultant reduction in BNP production more than offsets the increase in mature BNP mediated by inhibiting degradation by neprilysin, which lowers plasma BNP levels. These results suggest that even in the ARNI era, BNP can be used for diagnosis and assessment of the pathophysiology and prognosis of heart failure, though the mild increases early during ARNI administration should be taken into consideration.

Effects of sacubitril/valsartan on glycemia in patients with diabetes and heart failure: the PARAGON-HF and PARADIGM-HF trials

BACKGROUND

Compared with enalapril, sacubitril/valsartan lowered HbA1c and reduced new insulin therapy in patients with heart failure with reduced ejection fraction (HFrEF) and diabetes in the PARADIGM-HF trial. We sought to assess the glycemic effects of sacubitril/valsartan in heart failure with preserved ejection fraction (HFpEF) and diabetes, and across the spectrum of left ventricular ejection fraction (LVEF) in heart failure and diabetes.

METHODS

We compared the effect of sacubitril/valsartan, relative to valsartan, on HbA1c, new insulin therapy and hypoglycemia in the randomized controlled trial PARAGON-HF, and performed pooled analyses of PARAGON-HF and PARADIGM-HF.

RESULTS

Among 2395 patients with HFpEF and diabetes in PARAGON-HF, sacubitril/valsartan compared with valsartan reduced HbA1c (baseline-adjusted between-group difference in HbA1c change at 48 weeks: - 0.24%, 95% CI - 0.33 to - 0.16%, P < 0.001). Numerically, new insulin treatment was initiated less often in the sacubitril/valsartan group than in the valsartan group, but the difference was not statistically significant (12.8% vs. 16.1%; HR: 0.80, 95% CI 0.62-1.02, P = 0.07). Hypoglycemia adverse event reports were low, but more frequent in those receiving sacubitril/valsartan than in the valsartan group (4.2% vs. 2.6%; HR: 1.64, 95% CI 1.05-2.56, P = 0.030). In a pooled analysis of PARAGON-HF and PARADIGM-HF, the effect of sacubitril/valsartan on change in HbA1c was not significantly modified by LVEF (Pinteraction = 0.56). Across the spectrum of LVEF, sacubitril/valsartan reduced new insulin therapy (HR: 0.75, 95% CI 0.63-0.89, P = 0.001), compared with enalapril or valsartan.

CONCLUSIONS

Sacubitril/valsartan reduced HbA1c and new insulin therapy in patients with heart failure and diabetes across the spectrum of LVEF but may be associated with a slightly higher risk for hypoglycemia. Trial registration ClinicalTrials.gov NCT01920711.

Effect of Sacubitril/Valsartan on renal function in patients with chronic kidney disease and heart failure with preserved ejection fraction: A real-world 12-week study

Patients with chronic kidney disease (CKD) are often complicated with heart failure with preserved ejection fraction (HFpEF). However, several drugs, including angiotensin-converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB), have not shown apparent benefits in terms of morbidity and mortality of HFpEF. PARAMOUNT and other studies have shown the potential benefits of Sacubitril/Valsartan on patients with HFpEF, but its effects on renal function and the effect of low-dose Sacubitril/Valsartan in actual clinical conditions have not been thoroughly evaluated. In our longitudinal and observational research, 353 patients were followed up for 12 weeks. We evaluated renal function [urinary protein, serum creatinine and estimated glomerular filtration rate (eGFR)] and cardiac function [NT-proBNP (brain natriuretic peptide), New York Heart Association (NYHA) classification, left ventricular ejection fraction (LVEF), left atrial width and left ventricular end-diastolic width] at baseline and during follow-up. Worsening renal function (WRF) was defined as an increased serum creatinine≥26.5umol/L or decreased eGFR≥20%. The decline of eGFR in the Sacubitril/Valsartan group was slower than that in the control group (p = 0.021). The outcome of proteinuria in the ACEI/ARB group was significantly better than that in the Sacubitril/Valsartan group (p = 0.001). In terms of echocardiogram, the average left atrial width in Sacubitril/Valsartan group decreased by 1.38 ± 3.02 mm, which was significantly lower than that in the ACEI/ARB group (p = 0.02). The increase of urine protein class in the ACEI/ARB group increased the risk of WRF with statistical significance (OR = 2.36, 95%CI 1.01-5.49, p = 0.047), but no statistical significance was found in all the patients or Sacubitril/Valsartan group. In conclusion, Sacubitril/Valsartan could more effectively slow down renal function decline and reverse myocardial remodeling in patients with CKD and HFpEF than ACEI/ARB, even at low doses, though its protective effect on urinary protein is not as good as that of ACEI/ARB.

Real-world experience of angiotensin receptor neprilysin inhibitor on the glucose-lowering effect

We investigated the effect of angiotensin receptor neprilysin inhibitor (ARNI) on glycemic control in Korean patients. This retrospective cohort study was conducted at a single tertiary hospital. We compared the HbA_1c level reduction between the ARNI and angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) in chronic heart failure patients with diabetes. We also examined whether the target HbA_1c level was reached and the time to start insulin between the two groups. Over the study period, ARNI did not significantly lower the HbA_1c level after adjusting confounding factors compared to ACEIs or ARBs. However, as a result of a simple comparison using Mann–Whitney U test, ARNI group showed significant decrease in HbA_1c at 6, 12, and 24 months compared to ACEIs or ARBs group (p = 0.003, 0.009, and 0.026, respectively). The initiation of insulin was delayed in the ARNI group, but this difference was not significant based on the result of hazard ratio, but cumulative incidence was significantly lower in the ARNI group. In the real world, the blood glucose-control effects of ARNI were not superior to those of ACEIs or ARBs. However, long-term studies are needed as ARNI use increases to obtain more statistically significant results.

Insulinotropic Effects of Neprilysin and/or Angiotensin Receptor Inhibition in Mice

Treatment of heart failure with the angiotensin receptor-neprilysin inhibitor sacubitril/valsartan improved glycemic control in individuals with type 2 diabetes. The relative contribution of neprilysin inhibition versus angiotensin II receptor antagonism to this glycemic benefit remains unknown. Thus, we sought to determine the relative effects of the neprilysin inhibitor sacubitril versus the angiotensin II receptor blocker valsartan on beta-cell function and glucose homeostasis in a mouse model of reduced first-phase insulin secretion, and whether any beneficial effects are additive/synergistic when combined in sacubitril/valsartan. High fat-fed C57BL/6J mice treated with low-dose streptozotocin (or vehicle) were followed for eight weeks on high fat diet alone or supplemented with sacubitril, valsartan or sacubitril/valsartan. Body weight and fed glucose levels were assessed weekly. At the end of the treatment period, insulin release in response to intravenous glucose, insulin sensitivity, and beta-cell mass were determined. Sacubitril and valsartan, but not sacubitril/valsartan, lowered fasting and fed glucose levels and increased insulin release in diabetic mice. None of the drugs altered insulin sensitivity or beta-cell mass, but all reduced body weight gain. Effects of the drugs on insulin release were reproduced in angiotensin II-treated islets from lean C57BL/6J mice, suggesting the insulin response to each of the drugs is due to a direct effect on islets and mechanisms therein. In summary, sacubitril and valsartan each exert beneficial insulinotropic, glycemic and weight-reducing effects in obese and/or diabetic mice when administered alone; however, when combined, mechanisms within the islet contribute to their inability to enhance insulin release.

Brain Natriuretic Peptide Biomarkers in Current Clinical and Therapeutic Scenarios of Heart Failure

Brain natriuretic peptide (BNP) and its inactive N-terminal fragment, NT-proBNP, are serum biomarkers with key roles in the management of heart failure (HF). An increase in the serum levels of these peptides is closely associated with the pathophysiological mechanisms underlying HF such as the presence of structural and functional cardiac abnormalities, myocardial stretch associated with a high filling pressure and neuro-hormonal activation. As BNP and NT-proBNP measurements are possible, several studies have investigated their clinical utility in the diagnosis, prognostic stratification, monitoring and guiding therapy of patients with HF. BNP and NT-proBNP have also been used as criteria for enrollment in randomized trials evaluating the efficacy of new therapeutic strategies for HF. Nevertheless, the use of natriuretic peptides is still limited in clinical practice due to the controversial aspect of their use in different clinical settings. The purpose of this review is to discuss the main issues associated with using BNP and NT-proBNP serum levels in the management of patients with HF under current clinical and therapeutic scenarios.

Analyzing Corin–BNP–NEP Protein Pathway Revealing Differential Mechanisms in AF-Related Ischemic Stroke and No AF-Related Ischemic Stroke

Background

The incidence of atrial fibrillation (AF)-related stroke increases with aging. Natriuretic peptides (NPs) family, including Corin-B type natriuretic peptide (BNP)-neprilysin (NEP) protein levels increased with age and are risk markers of cardiovascular and cerebrovascular diseases, such as AF and cardioembolic stroke. Aging is also linked to epigenetics, specifically DNA methylation. However, only a few studies have investigated the effect of DNA methylation on the NP system. Thus, the present study aimed to investigate whether the Corin-BNP-NEP protein pathway is involved in the pathogenesis of AF-stroke and CpG methylation in the promoter region of the Corin protein gene has an effect on AF-related ischemic stroke.

Methods

A total of 82 patients hospitalized with acute ischemic strokes were enrolled in this study. The differences in clinical information were compared between the AF-stroke (n = 37) and no AF-stroke groups (n = 45). Plasma-soluble Corin and NEP were detected using an ELISA kit. CpG methylation in the promoter region of the gene was assessed by a next-generation sequencing-based bisulfite sequencing polymerase chain reaction (BSP).

Results

(1) Patients in AF-stroke were older, had higher initial NIHSS score, 90-day mRs, higher D2-dimer, INR, and APTT, and low TG, TC, and HbA1c (all p < 0.05). (2) Serum levels of Corin and BNP in the AF-stroke group were significantly higher than that in the no AF-stroke group (p < 0.05). No significant difference was detected in the serum levels of NEP between the two groups. (3) The levels of CpG methylation in the promoter region of the Corin protein gene in the AF-stroke group was significantly lower than that in the no AF-stroke group (p < 0.05). The CpG sites with maximal methylation differences between the two groups were CORIN:678, CORIN:682, CORIN:694, and CORIN:700.

Conclusion

The current findings raise the possibility that the Corin–BNP–NEP protein pathway may be involved in the pathogenesis of AF-related ischemic stroke. Deficient CpG methylation in the promoter region of the Corin protein gene is associated with AF-related ischemic stroke.

proANP Metabolism Provides New Insights Into Sacubitril/Valsartan Mode of Action

BACKGROUND

Sacubitril/valsartan (S/V) treatment is associated with clinical benefits in patients with heart failure with reduced ejection fraction (HFrEF), but its mode of action remains elusive, although it involves the increase of ANP (atrial natriuretic peptide).

METHODS AND RESULTS

Using a cohort of 73 HFrEF patients treated with S/V and controls, we deciphered the proteolytic cascade that converts proANP into 4 vasoactive peptides, including ANP, which exert vasodilatory actions. We found that proANP processing is sequential and involved meprin B, ECE (endothelin-converting enzyme) 1, and ANPEP (aminopeptidase N). This processing is limited in HFrEF patients when compared with controls via the downregulation of proANP production, corin, and meprin B activities by miR-425 and miR1-3p, resulting in limited production of proANP-derived bioactive peptides. S/V restored or compensated proANP processing by downregulating miR-425 and miR1-3p beyond levels observed in controls, hence increasing levels of proANP-derived bioactive peptides and vasodilation. In contrast, S/V directly and indirectly partially inhibited ECE1 and ANPEP. Consequently, ECE1 partial inhibition resulted in a lower-than-expected increase in ET1 (endothelin 1), tilting the vasoactive balance toward vasodilation, possibly explaining the hypotensive action of S/V. Finally, we show that proANP glycosylation interferes with the midregional proANP assay-a clinical surrogate for proANP production, preventing any pathophysiological interpretation of the results. Finally, the analysis of S/V dose escalation with respect to baseline treatments suggests S/V-specific effects.

CONCLUSIONS

These findings offer mechanistic evidence to the natriuretic peptide-defective state in HFrEF, which is improved by S/V. These data also strongly suggest that S/V increases plasma ANP by multiple mechanisms that involve the indirect regulation of 2 microRNAs, besides its protection from NEP (neprilysin) cleavage. Altogether, these data provide new insights on HFrEF pathophysiology and the mode of action of S/V.

Effects of Sacubitril-Valsartan on Clinical, Echocardiographic, and Polygraphic Parameters in Patients Affected by Heart Failure With Reduced Ejection Fraction and Sleep Apnea

Background

Heart failure with reduced ejection fraction (HFrEF) is a clinical condition frequently diagnosed in clinical practice. In patients affected by HFrEF, sleep apnea (SA) can be detected among the most frequent comorbidities. Sacubitril–valsartan (sac/val) association has been proven to be effective in reducing disease progression and all-cause mortality in HFrEF patients. Sac/val treatment can potentially attenuate SA development via several pathophysiologic mechanisms, including improvement of global hemodynamics, reduction of extracellular fluid overload, and decrease of sympathetic neural activity.

Methods

We recruited 132 patients affected by HFrEF and SA, already under treatment with continuous positive airway pressure (CPAP), which was discontinued 24 h before the scheduled study timepoints. Physical examination, echocardiography, nocturnal cardio-respiratory monitoring, and laboratory tests were performed in each patient at baseline and after a 6-month treatment with sac/val.

Results

After 6 months, sac/val induced statistically significant changes in clinical, hemodynamic, biohumoral (NT-proBNP, serum electrolytes, creatinine, and uric acid), and echocardiographic parameters. In particular, cardiac index (CI), both atrial and ventricular volumes and global longitudinal strain (GLS) improved. Moreover, polysomnography, carried out during a temporary CPAP interruption, revealed a significant reduction in global apnea-hypopnea index (AHI) value (p < 0.0001), central AHI (p < 0.0001), obstructive AHI (p < 0.0001), oxygen desaturation index (ODI) (p < 0.0001), and percentage time of saturation below 90% (TC90) (p < 0.0001). The changes of CI, estimated glomerular filtration rate (eGFR), NT-proBNP, and tricuspid annular plane excursion (TAPSE) contributed to 23.6, 7.6, 7.3, and 4.8% of AHI variability, respectively, and the whole model accounted for a 43.3% of AHI variation.

Conclusions

Our results suggest that treatment with sac/val is able to significantly improve the cardiorespiratory performance of patients with HFrEF and SA, integrating the positive impact of CPAP. Thus, both CPAP and sac/val therapy may synergistically contribute to lower the risks of both cardiac and pulmonary complications in HFrEF patients with SA.

Finding a reliable assay for soluble neprilysin

BACKGROUND

Lack of validation and standardization of research-use-only (RUO) immunoassays brings with it inherent threats to authenticity and functional quality. Poor correlation between different commercial neprilysin RUO immunoassays is concerning and discordant findings need to be resolved. We seek to identify and validate reliable neprilysin immunoassays to strengthen the scientific rigor and reproducibility of neprilysin-related investigation and of biomarker research in general.

METHODS

Soluble neprilysin (sNEP) concentrations were determined in cohorts (n = 532) from Spain (Cohort 1), New Zealand (NZ, Cohort 2) and Singapore (Cohort 3), using commercial kits from six vendors. Apparent sNEP concentrations were correlated between different assays and with plasma neprilysin activity. Assay reliability was further validated by performance verification, MS analysis and cross-reactivity tests.

RESULTS

sNEP in Cohorts 1 and 2 measured concurrently in Spain and NZ showed significant inter-laboratory correlation only for the Aviscera Bioscience sNEP ELISA SK00724-01. Neprilysin concentrations obtained with the R&D systems and SK00724-01 ELISAs correlated with each other but not with neprilysin activity. In Cohort 3, sNEP concentrations from the Perkin Elmer AlphaLISA and Biotechne ELLA assays agreed (r = 0.89) and both correlated with neprilysin activity (r = 0.87, 0.77 respectively). MS analysis detected authentic neprilysin in the AlphaLISA kit calibrator and in antibody pull-down material from human plasma. The AlphaLISA assay performed within acceptable limits (spike and recovery, dilutional linearity, inter- and intra-assay CV) and showed no cross-reactivity against neprilysin substrates and closely-related analogues.

CONCLUSION

AlphaLISA and ELLA assays provide reliable measures of sNEP concentrations. Reliability of other commercial neprilysin assays remains in question.

Heart Failure Treatments Such As Angiotensin Receptor/Neprilysin Inhibitor Improve Heart Failure Status and Glucose Metabolism

A recent study suggested that angiotensin receptor/neprilysin inhibitor (ARNI; sacubitril/valsartan) can improve functional capacity and cardiac reverse remodeling in patients with heart failure with reduced ejection fraction (HFrEF). Another study suggested that ARNI reduced glycated hemoglobin (HbA1c) in patients with diabetes and HFrEF; however, the details of its efficacy are unknown. We herein report a case of HFrEF with abnormal glucose metabolism in which ARNI was initiated. On the 7^th day of admission (before the initiation of ARNI), blood tests showed an abnormal glucose metabolism as follows: fasting blood glucose 134 mg/dL; and fasting blood insulin 11.4 µU/mL (homeostasis model assessment of insulin resistance (HOMA-IR) index 3.77; homeostasis model assessment of β-cell function (HOMA-β), 57.8%). On the 23^rd day after the initiation of ARNI, even though the patient was not using hypoglycemic drugs, his fasting blood glucose markedly decreased to 70 mg/dL without hypoglycemic symptoms, and his fasting blood insulin decreased to 5.4 µU/mL (HOMA-IR decreased to 0.93, HOMA-β increased to 277.7%). These results imply that ARNI has the potential to improve insulin resistance and the islet beta-cell function in patients with heart failure, in addition to the original effect of improving the hemodynamics, although the effect of improving the glucose metabolism is also considered to have been influenced by the improvement of the heart failure status and other drugs that the patient was taking.

Neprilysin inhibition improves intravenous but not oral glucose-mediated insulin secretion via GLP-1R signaling in mice with -cell dysfunction

Type 2 diabetes is associated with the upregulation of neprilysin, a peptidase capable of cleaving glucoregulatory peptides such as glucagon-like peptide-1 (GLP-1). In humans, use of the neprilysin inhibitor sacubitril in combination with an angiotensin II receptor blocker was associated with increased plasma GLP-1 levels and improved glycemic control. Whether neprilysin inhibition per se is mediating these effects remains unknown. We sought to determine whether pharmacological neprilysin inhibition on its own confers beneficial effects on glycemic status and β-cell function in a mouse model of reduced insulin secretion, and whether any such effects are dependent on GLP-1 receptor (GLP-1R) signaling. High-fat-fed male wild-type (Glp1r^+/+) and GLP-1R knockout (Glp1r^-/-) mice were treated with low-dose streptozotocin (STZ) to recapitulate type 2 diabetes-associated β-cell dysfunction, or vehicle as control. Mice were continued on high-fat diet alone or supplemented with the neprilysin inhibitor sacubitril for 8 wk. At the end of the study period, β-cell function was assessed by oral or intravenous glucose-tolerance test. Fasting and fed glucose were significantly lower in wild-type mice treated with sacubitril, although active GLP-1 levels and insulin secretion during oral glucose challenge were unchanged. In contrast, insulin secretion in response to intravenous glucose was significantly enhanced in sacubitril-treated wild-type mice, and this effect was blunted in Glp1r^-/- mice. Similarly, sacubitril enhanced insulin secretion in vitro in islets from STZ-treated Glp1r^+/+ but not Glp1r^-/- mice. Together, our data suggest the insulinotropic effects of pharmacological neprilysin inhibition in a mouse model of β-cell dysfunction are mediated via intra-islet GLP-1R signaling.NEW & NOTEWORTHY The neprilysin inhibitor, sacubitril, improves glycemic status in a mouse model of reduced insulin secretion. Sacubitril enhances intravenous but not oral glucose-mediated insulin secretion. The increased glucose-mediated insulin secretion is GLP-1 receptor-dependent. Neprilysin inhibition does not raise postprandial circulating active GLP-1 levels.

Effect of carperitide on the 1 year prognosis of patients with acute decompensated heart failure

Aims

Acute heart failure (AHF) is a clinical syndrome with a poor prognosis and a major public health concern worldwide. The aim of this study was to investigate whether carperitide administration improves the 1 year prognosis of patients with AHF and to check whether there is an optimal dose of the drug.

Methods and results

We analysed the data of COOPERATE‐HF‐J (the Consortium for Pooled Data Analysis regarding Hospitalized Patients with Heart Failure in Japan), combining two cohorts (NARA‐HF and REALITY‐AHF), which included 2435 patients with acute decompensated heart failure. The patients were divided into no carperitide (NO‐ANP, n = 1098); very low‐dose carperitide (VLD‐ANP, <0.02 μg/kg/min, n = 593); and low‐dose carperitide groups (LD‐ANP, ≥0.02 μg/kg/min, n = 744). The primary endpoint was cardiovascular mortality within 1 year after admission. The secondary endpoints were all‐cause mortality and rehospitalization due to worsening heart failure within 1 year after admission. The median carperitide doses in the VLD‐ANP and LD‐ANP groups were 0.013 and 0.025 μg/kg/min, respectively. Kaplan–Meier analysis showed that cardiovascular mortality and all‐cause mortality were significantly lower in the LD‐ANP group than in the NO‐ANP and VLD‐ANP groups (P < 0.001 and P = 0.002, respectively). Multivariable Cox regression analysis for cardiovascular and all‐cause mortality revealed that LD‐ANP was significantly associated with lower cardiovascular and all‐cause mortality within 1 year after admission, even after adjusting other covariates (hazard ratio: 0.696 and 0.791, 95% confidence interval: 0.513–0.944 and 0.628–0.997, P = 0.020 and 0.047, respectively).

Conclusions

Low‐dose carperitide was significantly associated with lower cardiovascular and all‐cause mortality within 1 year after admission. Our results suggest the necessity for well‐designed randomized controlled trials to determine the doses of carperitide that could improve clinical outcomes in patients with AHF.

Early B-Type Natriuretic Peptide Change in HFrEF Patients Treated With Sacubitril/Valsartan: A Pooled Analysis of EVALUATE-HF and PROVE-HF

OBJECTIVES

This study assessed changes in B-type natriuretic peptide (BNP) among patients with heart failure with reduced ejection fraction (HFrEF) treated with sacubitril/valsartan (Sac/Val) according to standard prescribing information.

BACKGROUND

Through inhibition of neprilysin, Sac/Val may increase BNP concentrations.

METHODS

In an individual patient analysis from the EVALUATE-HF (Study of Effects of Sacubitril/Valsartan vs. Enalapril on Aortic Stiffness in Patients With Mild to Moderate HF With Reduced Ejection Fraction) (n = 221) and the PROVE-HF (Effects of Sacubitril/Valsartan Therapy on Biomarkers, Myocardial Remodeling and Outcomes) (n = 146) studies, we examined changes in BNP, N-terminal pro-BNP (NT-proBNP), and urinary cyclic guanosine monophosphate (ucGMP) from baseline to week 4 and week 12.

RESULTS

Median (IQRs) concentration of BNP at baseline, week 4, and week 12 were 145 [IQR: 55-329], 136 [IQR: 50-338], and 135 [IQR: 51-299] ng/L, respectively. There was no significant change from baseline to week 4 (0% [-30% to +41%]; P = 0.36) or week 12 (+1% [-36% to +50%]; P = 0.97). By week 12, one-half of the study participants had a BNP decline. There was no association between Sac/Val dose and BNP changes. Change in BNP was directly associated with change in NT-proBNP (rho: = 0.81; P < 0.001), which decreased by -30% (-50% to -8%) and -32% (-54% to -1%) to weeks 4 and 12 (P < 0.001 for both). In contrast, change in BNP was only weakly associated with change in ucGMP (rho: = 0.19; P < 0.001). Increases in ucGMP were observed regardless of whether BNP was decreased (+11% [-34% to +115%]), unchanged (+34% [-15% to +205%]), or increased (+57% [-12% to +14%]).

CONCLUSIONS

In this pooled analysis of patients with HFrEF with standard indications for Sac/Val treatment, there was no significant overall increase in BNP concentrations, and patients demonstrated increase in ucGMP regardless of the trajectory of BNP change. (Study of Effects of Sacubitril/Valsartan vs. Enalapril on Aortic Stiffness in Patients With Mild to Moderate HF With Reduced Ejection Fraction [EVALUATE-HF]; NCT02874794) (Effects of Sacubitril/Valsartan Therapy on Biomarkers, Myocardial Remodeling and Outcomes [PROVE-HF]; NCT02887183).

Evaluating sacubitril/valsartan as a treatment option for heart failure with reduced ejection fraction and preserved ejection fraction

INTRODUCTION

Sacubitril/valsartan is the first-in-class angiotensin-receptor neprilysin inhibitor approved in 2015 for the treatment of heart failure with reduced ejection fraction (HFrEF). On 16 February 2021, the Food and Drug Administration acknowledged that "Benefits are most clearly evident in patients with left ventricular ejection fraction below normal," thus potentially extending the use in subjects with heart failure and preserved ejection fraction (HFpEF).

AREAS COVERED

The authors outline the regulatory history, pharmacokinetics, pharmacodynamics, and risk-benefit profile of sacubitril/valsartan in HFrEF and HFpEF. A critical cross-trial comparison is presented, including sodium-glucose cotransporter 2 inhibitors (SGLT2i), together with an insight into the latest European Society of Cardiology guidelines, where the new category of heart failure with mildly reduced ejection fraction is introduced.

EXPERT OPINION

Sacubitril/valsartan is a foundation of the pharmacological armamentarium in HFrEF to counteract the neuro-hormonal changes and reverse cardiac remodeling, together with beta-blockers, SGLT2i and mineralocorticoid receptor antagonists. The optimal sequence algorithm is an evolving issue, and the authors provide the reader with their personal perspective. A multidisciplinary management is encouraged to minimize the therapeutic inertia and manage tolerability issues, thus supporting adherence. Pragmatic trials, pharmacovigilance, and high-quality real-world evidence are crucial toward personalized safe prescribing of sacubitril/valsartan.

Long-Term Mortality and Morbidity Related to Congestive Heart Failure with Reduced Ejection Fraction (CHFrEF) in Palestinian Patients Maintained on Submaximal Sacubitril/Valsartan Doses: A Pilot Study

Background

The efficacy of sacubitril/valsartan, a newly introduced combination drug for heart failure with reduced ejection fraction (HFrEF), was demonstrated in the PARADIGM-HF trial conducted in Western countries. However, these findings need to be verified in the Middle Eastern context, where patients may exhibit a different response due to different environmental and racial factors.

Objectives

The goal of this study was to evaluate the efficacy of submaximal sacubitril/valsartan doses in terms of improving the disease symptoms, as measured by the New York Heart Association (NYHA) classification and left ventricular ejection fraction (LVEF) percentage, as well as establish long-term morbidity and mortality associated with HFrEF among Palestinian patients administered target doses of an angiotensin-converting enzyme inhibitors (ACEI) or angiotensin II receptor blockers (ARBs). Material and Methods. This study involved a retrospective review of charts related to patients with HFrEF maintained on sacubitril/valsartan and was conducted in a referral cardiology clinic in Palestine. The inclusion criteria were age 18+, HFrEF diagnosis, sacubitril/valsartan usage for at least six months during the period between January 1, 2016, and June 30, 2019, and LVEF < 40%. The exclusion criteria included LVEF ≥ 40% and drug administration duration < 6 months. The collected data included NYHA class, as well as LVEF, serum sodium (Na), potassium (K), serum creatinine (Cr), and blood urea nitrogen (BUN) levels and the mortality rate before and after the minimum treatment duration. IBM SPSS STATISTICS for Windows, version 20.0, Armonk, NY: IBM Corp. IBM Corp., released 2012, was used for data analysis, whereby T score was calculated for comparisons between numerical groups, and p < 0.05 was considered statistically significant.

Results

The initial study sample comprised of 205 consecutive patients with HFrEF maintained on sacubitril/valsartan for at least six months from January 1, 2016, to June 30, 2019. Three patients were excluded due to attrition, along with further 12 patients with LVEF ≥ 40% (based on the PARADIGM-HF trial criteria). Throughout the treatment period, most patients showed escalating improvement in terms of the LVEF and NYHA classification, as LVEF = 29.8% and NYHA = 3 were obtained on average before initiating sacubitril/valsartan, compared to 41% and 1.7, respectively, after 6-month treatment (p = 0.0003 and 0.046, respectively). These improvements in LVEF and NYHA class were noted across all sacubitril/valsartan doses (50−400 mg). However, 23 patients (12%) died while undergoing sacubitril/valsartan treatment.

Conclusion

A significant long-term reduction in the mortality and morbidity rates was observed in Palestinian patients with HFrEF maintained on submaximal doses of sacubitril/valsartan.

Cardiovascular therapeutics: A new potential for anxiety treatment?

Besides the well‐recognized risk factors, novel conditions increasing cardiovascular morbidity and mortality are emerging. Undesirable emotions and behavior such as anxiety and depression, appear to participate in worsening cardiovascular pathologies. On the other hand, deteriorating conditions of the heart and vasculature result in disturbed mental and emotional health. The pathophysiological background of this bidirectional interplay could reside in an inappropriate activation of vegetative neurohormonal and other humoral systems in both cardiovascular and psychological disturbances. This results in circulus vitiosus potentiating mental and circulatory disorders. Thus, it appears to be of utmost importance to examine the alteration of emotions, cognition, and behavior in cardiovascular patients. In terms of this consideration, recognizing the potential of principal cardiovascular drugs to interact with the mental state in patients with heart or vasculature disturbances is unavoidable, to optimize their therapeutic benefit. In general, beta‐blockers, central sympatholytics, ACE inhibitors, ARBs, aldosterone receptor blockers, sacubitril/valsartan, and fibrates are considered to exert anxiolytic effect in animal experiments and clinical settings. Statins and some beta‐blockers appear to have an equivocal impact on mood and anxiety and ivabradine expressed neutral psychological impact. It seems reasonable to suppose that the knowledge of a patient's mood, cognition, and behavior, along with applying careful consideration of the choice of the particular cardiovascular drug and respecting its potential psychological benefit or harm might improve the individualized approach to the treatment of cardiovascular disorders.

A year in heart failure: an update of recent findings

Major changes have occurred in these last years in heart failure (HF) management. Landmark trials and the 2021 European Society of Cardiology guidelines for the diagnosis and treatment of HF have established four classes of drugs for treatment of HF with reduced ejection fraction: angiotensin‐converting enzyme inhibitors or an angiotensin receptor‐neprilysin inhibitor, beta‐blockers, mineralocorticoid receptor antagonists, and sodium‐glucose co‐transporter 2 inhibitors, namely, dapagliflozin or empagliflozin. These drugs consistently showed benefits on mortality, HF hospitalizations, and quality of life. Correction of iron deficiency is indicated to improve symptoms and reduce HF hospitalizations. AFFIRM‐AHF showed 26% reduction in total HF hospitalizations with ferric carboxymaltose vs. placebo in patients hospitalized for acute HF (P = 0.013). The guanylate cyclase activator vericiguat and the myosin activator omecamtiv mecarbil improved outcomes in randomized placebo‐controlled trials, and vericiguat is now approved for clinical practice. Treatment of HF with preserved ejection fraction (HFpEF) was a major unmet clinical need until this year when the results of EMPEROR‐Preserved (EMPagliflozin outcomE tRial in Patients With chrOnic HFpEF) were issued. Compared with placebo, empagliflozin reduced by 21% (hazard ratio, 0.79; 95% confidence interval, 0.69 to 0.90; P < 0.001), the primary outcome of cardiovascular death or HF hospitalization. Advances in the treatment of specific phenotypes of HF, including atrial fibrillation, valvular heart disease, cardiomyopathies, cardiac amyloidosis, and cancer‐related HF, also occurred. Coronavirus disease 2019 (COVID‐19) pandemic still plays a major role in HF epidemiology and management. All these aspects are highlighted in this review.

Sacubitril-Valsartan, Clinical Benefits and Related Mechanisms of Action in Heart Failure With Reduced Ejection Fraction. A Review

Heart failure (HF) is a clinical syndrome characterized by the presence of dyspnea or limited exertion due to impaired cardiac ventricular filling and/or blood ejection. Because of its high prevalence, it is a major health and economic burden worldwide. Several mechanisms are involved in the pathophysiology of HF. First, the renin-angiotensin-aldosterone system (RAAS) is over-activated, causing vasoconstriction, hypertension, elevated aldosterone levels and sympathetic tone, and eventually cardiac remodeling. Second, an endogenous compensatory mechanism, the natriuretic peptide (NP) system is also activated, albeit insufficiently to counteract the RAAS effects. Since NPs are degraded by the enzyme neprilysin, it was hypothesized that its inhibition could be an important therapeutic target in HF. Sacubitril/valsartan is the first of the class of dual neprilysin and angiotensin receptor inhibitors (ARNI). In patients with HFrEF, treatment with sacubitril/valsartan has demonstrated to significantly reduce mortality and the rates of hospitalization and rehospitalization for HF when compared to enalapril. This communication reviews in detail the demonstrated benefits of sacubitril/valsartan in the treatment of patients with HFrEF, including reduction of mortality and disease progression as well as improvement in cardiac remodeling and quality of life. The hemodynamic and organic effects arising from its dual mechanism of action, including the impact of neprilysin inhibition at the renal level, especially relevant in patients with type 2 diabetes mellitus, are also reviewed. Finally, the evidence on the demonstrated safety and tolerability profile of sacubitril/valsartan in the different subpopulations studied has been compiled. The review of this evidence, together with the recommendations of the latest clinical guidelines, position sacubitril/valsartan as a fundamental pillar in the treatment of patients with HFrEF.

The Natriuretic Peptides for Hypertension Treatment

Hypertension is a common pathological condition predisposing to a higher occurrence of cardiovascular diseases and events. Unfortunately, treatment of hypertension is still suboptimal worldwide. More efforts are needed to implement the availability of anti-hypertensive drugs. The family of natriuretic peptides, including atrial and brain natriuretic peptides (ANP and BNP), play a key role on blood pressure regulation through the natriuretic, diuretic and vasorelaxant effects. A large number of experimental and human studies, ranging from pathophysiological to genetic investigations, supported ANP as the most relevant component of the family able to modulate blood pressure and to contribute to hypertension development. On this background, it is expected that ANP-based therapeutic approaches may give a significant contribution to the development of efficacious therapies against hypertension. Since native ANP cannot be administered due to its short half-life, several approaches were attempted over the years to overcome the difficulties inherent to the ANP instability. These approaches included ANP recombinant and fusion peptides, gene therapy, inhibition of ANP degradation by neprilysin inhibition, and designer peptides. The most relevant achievements in the field are discussed in this article. Based on the available evidence, therapies targeting ANP represent efficacious and clinically applicable anti-hypertensive agents.

Inhibition of phosphodiesterase type 9 reduces obesity and cardiometabolic syndrome in mice

Central obesity with cardiometabolic syndrome (CMS) is a major global contributor to human disease, and effective therapies are needed. Here, we show that cyclic GMP-selective phosphodiesterase 9A inhibition (PDE9-I) in both male and ovariectomized female mice suppresses preestablished severe diet-induced obesity/CMS with or without superimposed mild cardiac pressure load. PDE9-I reduces total body, inguinal, hepatic, and myocardial fat; stimulates mitochondrial activity in brown and white fat; and improves CMS, without significantly altering activity or food intake. PDE9 localized at mitochondria, and its inhibition in vitro stimulated lipolysis in a PPARα-dependent manner and increased mitochondrial respiration in both adipocytes and myocytes. PPARα upregulation was required to achieve the lipolytic, antiobesity, and metabolic effects of PDE9-I. All these PDE9-I-induced changes were not observed in obese/CMS nonovariectomized females, indicating a strong sexual dimorphism. We found that PPARα chromatin binding was reoriented away from fat metabolism-regulating genes when stimulated in the presence of coactivated estrogen receptor-α, and this may underlie the dimorphism. These findings have translational relevance given that PDE9-I is already being studied in humans for indications including heart failure, and efficacy against obesity/CMS would enhance its therapeutic utility.

Recent advances in pharmacological treatment of heart failure

BACKGROUND

Over the last years, several trials offered new evidence on heart failure (HF) treatment.

DESIGN AND RESULTS

For HF with reduced left ventricular ejection fraction, type 2 sodium-glucose cotransporter inhibitors, aside from sacubitril-valsartan, demonstrated extraordinary efficacy in ameliorating patients' prognosis. Some new molecules (eg vericiguat, omecamtiv mecarbil and ferric carboxymaltose) correct iron deficiency and have shown to be capable of furthering reducing the burden of HF hospitalisation. Finally, there is new evidence on the possible therapeutic approaches of HF patients with mid-range or preserved left ventricular ejection fraction.

CONCLUSIONS

This review aimed to revise the main novelties in the field of HF therapy and focus on how the daily clinical approach to patient treatment is changing.

Towards precision medicine in heart failure

The number of therapies for heart failure (HF) with reduced ejection fraction has nearly doubled in the past decade. In addition, new therapies for HF caused by hypertrophic and infiltrative disease are emerging rapidly. Indeed, we are on the verge of a new era in HF in which insights into the biology of myocardial disease can be matched to an understanding of the genetic predisposition in an individual patient to inform precision approaches to therapy. In this Review, we summarize the biology of HF, emphasizing the causal relationships between genetic contributors and traditional structure-based remodelling outcomes, and highlight the mechanisms of action of traditional and novel therapeutics. We discuss the latest advances in our understanding of both the Mendelian genetics of cardiomyopathy and the complex genetics of the clinical syndrome presenting as HF. In the phenotypic domain, we discuss applications of machine learning for the subcategorization of HF in ways that might inform rational prescribing of medications. We aim to bridge the gap between the biology of the failing heart, its diverse clinical presentations and the range of medications that we can now use to treat it. We present a roadmap for the future of precision medicine in HF.

Relevance of Neutrophil Neprilysin in Heart Failure

Significant expression of neprilysin (NEP) is found on neutrophils, which present the transmembrane integer form of the enzyme. This study aimed to investigate the relationship of neutrophil transmembrane neprilysin (mNEP) with disease severity, adverse remodeling, and outcome in HFrEF. In total, 228 HFrEF, 30 HFpEF patients, and 43 controls were enrolled. Neutrophil mNEP was measured by flow-cytometry. NEP activity in plasma and blood cells was determined for a subset of HFrEF patients using mass-spectrometry. Heart failure (HF) was characterized by reduced neutrophil mNEP compared to controls (p < 0.01). NEP activity on peripheral blood cells was almost 4-fold higher compared to plasma NEP activity (p = 0.031) and correlated with neutrophil mNEP (p = 0.006). Lower neutrophil mNEP was associated with increasing disease severity and markers of adverse remodeling. Higher neutrophil mNEP was associated with reduced risk for mortality, total cardiovascular hospitalizations, and the composite endpoint of both (p < 0.01 for all). This is the first report describing a significant role of neutrophil mNEP in HFrEF. The biological relevance of neutrophil mNEP and exact effects of angiotensin-converting-enzyme inhibitors (ARNi) at the neutrophil site have to be determined. However, the results may suggest early initiation of ARNi already in less severe HF disease, where effects of NEP inhibition may be more pronounced.

Soluble GC stimulators and activators: Past, present and future

The discovery of soluble GC (sGC) stimulators and sGC activators provided valuable tools to elucidate NO-sGC signalling and opened novel pharmacological opportunities for cardiovascular indications and beyond. The first-in-class sGC stimulator riociguat was approved for pulmonary hypertension in 2013 and vericiguat very recently for heart failure. sGC stimulators enhance sGC activity independent of NO and also act synergistically with endogenous NO. The sGC activators specifically bind to, and activate, the oxidised haem-free form of sGC. Substantial research efforts improved on the first-generation sGC activators such as cinaciguat, culminating in the discovery of runcaciguat, currently in clinical Phase II trials for chronic kidney disease and diabetic retinopathy. Here, we highlight the discovery and development of sGC stimulators and sGC activators, their unique modes of action, their preclinical characteristics and the clinical studies. In the future, we expect to see more sGC agonists in new indications, reflecting their unique therapeutic potential.