Effect of Neprilysin Inhibition on Various Natriuretic Peptide Assays

Biomarkers of Hemodynamic Congestion in Heart Failure

PURPOSE OF REVIEW

The purpose of this review is to describe the evidence behind various blood and imaging-based biomarkers that can improve the identification of congestion when not clearly evident on routine examination.

RECENT FINDINGS

The natriuretic peptides (NPs) BNP and NT-proBNP have been shown to closely correlate with intra-cardiac filling pressures, both at baseline and when trended following improvement in congestion. Additionally, NPs rise well before clinical congestion is apparent so can be used as a tool to help identify subclinical HF decompensation. Additional serum-based biomarkers including MR-proANP and CA-125 can be helpful in assisting with diagnostic certainty when BNP or NT-proBNP are in the "grey zone" or when factors are present which may confound NP levels. Additionally, the emerging use of ultrasound techniques may enhance our ability to fine-tune the assessment and treatment of congestion. Biomarkers, including the blood-based natriuretic peptides and markers on bedside point of care ultrasound, can be used as non-invasive indices of hemodynamic congestion. These biomarkers are particularly valuable to incorporate when the degree of a patient's congestion is not apparent on clinical exam, and they can provide important prognostic information and help guide clinical management.

Emerging Role of Natriuretic Peptides in Diabetes Care: A Brief Review of Pertinent Recent Literature

Diabetes markedly increases susceptibility to adverse cardiovascular events, including heart failure (HF), leading to heightened morbidity and mortality rates. Elevated levels of natriuretic peptides (NPs), notably B-type natriuretic peptide (BNP) and N-terminal-proBNP (NT-proBNP), correlate with cardiac structural and functional abnormalities, aiding in risk stratification and treatment strategies in individuals with diabetes. This article reviews the intricate relationship between diabetes and HF, emphasizing the role of NPs in risk assessment and guiding therapeutic strategies, particularly in individuals with type 2 diabetes mellitus (T2DM). We also explore the analytical and clinical considerations in the use of natriuretic peptide testing and the challenges and prospects of natriuretic-peptide-guided therapy in managing cardiovascular risk in patients with diabetes. We conclude with some reflections on future prospects for NPs.

Angiotensin Receptor-Neprilysin Inhibitor Suppresses Renin-Angiotensin-Aldosterone System Activation After Cardiac Surgery Using Cardiopulmonary Bypass

BACKGROUND

Sacubitril/valsartan, being both a neprilysin inhibitor and angiotensin receptor blocker, exhibits a renin-angiotensin-aldosterone system (RAAS) inhibitory effect. However, no study has investigated the administration of sacubitril/valsartan in patients early after surgery using cardiopulmonary bypass.

METHODS AND RESULTS

This was a prospective observational study of 63 patients who underwent open heart surgery and were treated with sacubitril/valsartan. No serious adverse events occurred. Among the 63 patients, sacubitril/valsartan was discontinued in 13 due to hypotension (n=10), renal dysfunction (n=2), and dizziness (n=1). Atrial natriuretic peptide concentrations increased significantly from Day 3 of treatment (P=0.0142 vs. Postoperative Day 1) and remained high thereafter. In contrast, plasma renin activity was significantly suppressed from Day 3 onwards (P=0.00206 vs. Postoperative Day 1). A decrease in creatinine concentrations and an increase in the estimated glomerular filtration rate were observed on Day 3; this improvement in renal function was not observed in the historical control group, in which patients did not receive sacubitril/valsartan. New postoperative atrial fibrillation was less frequent in the study group compared with the historical control (12.7% vs. 38.0%; P=0.0034).

CONCLUSIONS

Sacubitril/valsartan administration was safe immediately after open heart surgery in patients without postoperative hypotension. It enhanced serum atrial natriuretic peptide concentrations and suppressed RAAS activation.

Possible role of LCZ696 in atherosclerosis: new inroads and perspective

LCZ696 blocks both angiotensin receptor type 1 (ATR1) and neprilysin (NEP), which are intricate in the degradation of natriuretic peptides (NPs) and other endogenous peptides. It has been shown NEP inhibitors and LCZ696 could be effectively in the management of atherosclerosis (AS). However, the underlying mechanism of LCZ696 in AS is needed to be clarified entirely. Hence, this review is directed to reconnoiter the mechanistic role of LCZ696 in AS. The anti-inflammatory role of LCZ696 is related to the inhibition of transforming growth factor beta (TGF-β)-activated kinase 1 (TAK) and nod-like receptor pyrin 3 receptor (NLRP3) inflammasome. Moreover, LCZ696, via inhibition of pro-inflammatory cytokines, oxidative stress, apoptosis and endothelial dysfunction can attenuate the development and progression of AS. In conclusion, LCZ696 could be effective in the management of AS through modulation of inflammatory and oxidative signaling. Preclinical and clinical studies are recommended in this regard.

Effects of angiotensin receptor-neprilysin inhibitor on ketone body metabolism in pre-heart failure/heart failure patients

Recently, a mild elevation of the blood ketone levels was found to exert multifaceted cardioprotective effects. To investigate the effect of angiotensin receptor neprilysin inhibitors (ARNIs) on the blood ketone body levels, 46 stable pre-heart failure (HF)/HF patients were studied, including 23 who switched from angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) to ARNIs (ARNI group) and 23 who continued treatment with ACE inhibitors or ARBs (control group). At baseline, there were no significant differences in the total ketone body (TKB) levels between the two groups. Three months later, the TKB levels in the ARNI group were higher than the baseline values (baseline to 3 months: 71 [51, 122] to 92 [61, 270] μmol/L, P < 0.01). In the control group, no significant change was observed between the baseline and 3 months later. A multiple regression analysis demonstrated that the initiation of ARNI and an increase in the blood non-esterified fatty acid (NEFA) levels at 3 months increased the percentage changes in the TKB levels from baseline to 3 months (%ΔTKB level) (initiation of ARNI: P = 0.017, NEFA level at 3 months: P < 0.001). These results indicate that ARNI administration induces a mild elevation of the blood TKB levels in pre-HF/HF patients.

Association of natriuretic peptides and receptor activity with cardio-metabolic health at middle age

Natriuretic peptides (NP) have multiple actions benefitting cardiovascular and metabolic health. Although many of these are mediated by Guanylyl Cyclase (GC) receptors NPR1 and NPR2, their role and relative importance in vivo is unclear. The intracellular mediator of NPR1 and NPR2, cGMP, circulates in plasma and can be used to examine relationships between receptor activity and tissue responses targeted by NPs. Plasma cGMP was measured in 348 participants previously recruited in a multidisciplinary community study (CHALICE) at age 50 years at a single centre. Associations between bio-active NPs and bio-inactive aminoterminal products with cGMP, and of cGMP with tissue response, were analysed using linear regression. Mediation of associations by NPs was assessed by Causal Mediation Analysis (CMA). ANP's contribution to cGMP far exceed those of other NPs. Modelling across three components (demographics, NPs and cardiovascular function) shows that ANP and CNP are independent and positive predictors of cGMP. Counter intuitively, findings from CMA imply that in specific tissues, NPR1 responds more to BNP stimulation than ANP. Collectively these findings align with longer tissue half-life of BNP, and direct further therapeutic interventions towards extending tissue activity of ANP and CNP.

Role of NT-proBNP and lung ultrasound in diagnosing and classifying heart failure in a hospitalized oldest-old population: a cross-sectional study

AIM

Diagnosing and classifying heart failure (HF) in the oldest-old patients has technical and interpretation issues, especially in the acute setting. We assessed the usefulness of both N-terminal pro-brain natriuretic peptide (NT-proBNP) and lung ultrasound (LUS) for confirming HF diagnosis and predicting, among hospitalized HF patients, those with reduced ejection fraction (HFrEF).

METHODS

We performed a cross-sectional study on 148 consecutive patients aged ≥ 80 years admitted to our Internal Medicine and Geriatrics ward with at least one symptom/sign compatible with HF and NT-proBNP ≥ 125 pg/mL. We measured serum NT-proBNP levels and performed LUS and transthoracic echocardiography (TTE) on admission before diuretic therapy. We divided our cohort into three subgroups according to the left ventricular ejection fraction (LVEF): reduced (LVEF ≤ 40%), mildly-reduced (LVEF = 41-49%) and preserved (LVEF ≥ 50%).

RESULTS

The mean age was 88±5 years. Male prevalence was 42%. Patients with HFrEF were 19%. Clinical features and laboratory parameters did not differ between the three subgroups, except for higher NT-proBNP in HFrEF patients, which also had a higher number of total B-lines and intercostal spaces of pleural effusion at LUS. Overall, NT-proBNP showed an inverse correlation with LVEF (r = -0.22, p = 0.007) and a direct correlation with age, total pulmonary B-lines, and intercostal spaces of pleural effusion. According to the ROCs, NT-proBNP levels, pulmonary B-lines and pleural effusion extension were poorly predictive for HFrEF. The best-performing cut-offs were 9531 pg/mL for NT-proBNP (SP 0.70, SE 0.50), 13 for total B-lines (SP 0.69, SE 0.85) and one intercostal space for pleural effusion (SP 0.55, SE 0.89). Patients with admission NT-proBNP ≥ 9531 pg/mL had a 2-fold higher risk for HFrEF (OR 2.5, 95% CI 1.3-4.9), while we did not find any association for total B-lines ≥ 13 or pleural effusion ≥ 1 intercostal space with HFrEF. A significant association with HFrEF emerged for the combination of NT-proBNP ≥ 9531 pg/mL, total B-lines ≥ 13 and intercostal spaces of pleural effusion ≥ 1 (adjusted OR 4.3, 95% CI 1.5-12.9).

CONCLUSIONS

Although NT-proBNP and LUS help diagnose HF, their accuracy in discriminating HFrEF from non-HFrEF was poor in our real-life clinical study on oldest-old hospitalized patients, making the use of TTE still necessary to distinguish HF phenotypes in this peculiar setting. These data require confirmation in more extensive and longer prospective studies.

CNP Ameliorates Macrophage Inflammatory Response and Atherosclerosis

BACKGROUND

CNP (C-type natriuretic peptide), an endogenous short peptide in the natriuretic peptide family, has emerged as an important regulator to govern vascular homeostasis. However, its role in the development of atherosclerosis remains unclear. This study aimed to investigate the impact of CNP on the progression of atherosclerotic plaques and elucidate its underlying mechanisms.

METHODS

Plasma CNP levels were measured in patients with acute coronary syndrome. The potential atheroprotective role of CNP was evaluated in apolipoprotein E-deficient (ApoE-/-) mice through CNP supplementation via osmotic pumps, genetic overexpression, or LCZ696 administration. Various functional experiments involving CNP treatment were performed on primary macrophages derived from wild-type and CD36 (cluster of differentiation 36) knockout mice. Proteomics and multiple biochemical analyses were conducted to unravel the underlying mechanism.

RESULTS

We observed a negative correlation between plasma CNP concentration and the burden of coronary atherosclerosis in patients. In early atherosclerotic plaques, CNP predominantly accumulated in macrophages but significantly decreased in advanced plaques. Supplementing CNP via osmotic pumps or genetic overexpression ameliorated atherosclerotic plaque formation and enhanced plaque stability in ApoE-/- mice. CNP promoted an anti-inflammatory macrophage phenotype and efferocytosis and reduced foam cell formation and necroptosis. Mechanistically, we found that CNP could accelerate HIF-1α (hypoxia-inducible factor 1-alpha) degradation in macrophages by enhancing the interaction between PHD (prolyl hydroxylase domain-containing protein) 2 and HIF-1α. Furthermore, we observed that CD36 bound to CNP and mediated its endocytosis in macrophages. Moreover, we demonstrated that the administration of LCZ696, an orally bioavailable drug recently approved for treating chronic heart failure with reduced ejection fraction, could amplify the bioactivity of CNP and ameliorate atherosclerotic plaque formation.

CONCLUSIONS

Our study reveals that CNP enhanced plaque stability and alleviated macrophage inflammatory responses by promoting HIF-1α degradation, suggesting a novel atheroprotective role of CNP. Enhancing CNP bioactivity may offer a novel pharmacological strategy for treating related diseases.

Predictive biomarkers for the early detection and management of heart failure

Cardiovascular disease (CVD) is a serious public health concern whose incidence has been on a rise and is projected by the World Health Organization to be the leading global cause of mortality by 2030. Heart failure (HF) is a complicated syndrome resulting from various CVDs of heterogeneous etiologies and exhibits varying pathophysiology, including activation of inflammatory signaling cascade, apoptosis, fibrotic pathway, and neuro-humoral system, thereby leading to compromised cardiac function. During this process, several biomolecules involved in the onset and progression of HF are released into circulation. These circulating biomolecules could serve as unique biomarkers for the detection of subclinical changes and can be utilized for monitoring disease severity. Hence, it is imperative to identify these biomarkers to devise an early predictive strategy to stop the deterioration of cardiac function caused by these complex cellular events. Furthermore, measurement of multiple biomarkers allows clinicians to divide HF patients into sub-groups for treatment and management based on early health outcomes. The present article provides a comprehensive overview of current omics platform available for discovering biomarkers for HF management. Some of the existing and novel biomarkers for the early detection of HF with special reference to endothelial biology are also discussed.

From Beats to Metabolism: the Heart at the Core of Interorgan Metabolic Cross Talk

The heart, once considered a mere blood pump, is now recognized as a multifunctional metabolic and endocrine organ. Its function is tightly regulated by various metabolic processes, at the same time it serves as an endocrine organ, secreting bioactive molecules that impact systemic metabolism. In recent years, research has shed light on the intricate interplay between the heart and other metabolic organs, such as adipose tissue, liver, and skeletal muscle. The metabolic flexibility of the heart and its ability to switch between different energy substrates play a crucial role in maintaining cardiac function and overall metabolic homeostasis. Gaining a comprehensive understanding of how metabolic disorders disrupt cardiac metabolism is crucial, as it plays a pivotal role in the development and progression of cardiac diseases. The emerging understanding of the heart as a metabolic and endocrine organ highlights its essential contribution to whole body metabolic regulation and offers new insights into the pathogenesis of metabolic diseases, such as obesity, diabetes, and cardiovascular disorders. In this review, we provide an in-depth exploration of the heart's metabolic and endocrine functions, emphasizing its role in systemic metabolism and the interplay between the heart and other metabolic organs. Furthermore, emerging evidence suggests a correlation between heart disease and other conditions such as aging and cancer, indicating that the metabolic dysfunction observed in these conditions may share common underlying mechanisms. By unraveling the complex mechanisms underlying cardiac metabolism, we aim to contribute to the development of novel therapeutic strategies for metabolic diseases and improve overall cardiovascular health.

Differential Associations of A-/B-Type Natriuretic Peptides With Cardiac Structure, Function, and Prognosis in Heart Failure

BACKGROUND

Natriuretic peptide (NP) elevations are prognostic in heart failure (HF), but relative atrial NP deficiency in acute HF has been suggested.

OBJECTIVES

The authors compared plasma concentrations and relative strength of associations of A- and B-type NPs with cardiac structure/function and clinical outcomes in HF.

METHODS

Midregional pro-atrial natriuretic peptide (MR-proANP), B-type natriuretic peptide (BNP), and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were measured in patients with compensated HF in a prospective, multicenter study. The primary outcome was a composite of HF-hospitalization or all-cause mortality. Secondary outcomes included individual primary outcome components and cardiovascular admission.

RESULTS

Among 1,278 patients (age 60.1 ± 12.1 years, 82% men, left ventricular ejection fraction [LVEF] 34% ± 14%), median concentrations of MR-proANP were 990 pg/mL (Q1-Q3: 557-1,563 pg/mL), NT-proBNP 1,648 pg/mL (Q1-Q3: 652-3,960 pg/mL), and BNP 291 pg/mL (Q1-Q3: 103-777 pg/mL). No subpopulation with inappropriately low MR-proANP (relative to BNP/NT-proBNP) was observed. Clinical event rates were similar for biomarker tertiles. Increments in MR-proANP exhibited steeper associations with concurrent shifts in left ventricular size, diastolic indexes and LVEF than BNP/NT-proBNP at baseline and serially (P < 0.05), and lower odds of beneficial left ventricular reverse remodeling: OR: 0.35 (95% CI: 0.18-0.70). In single-biomarker models, MR-proANP(log10) was associated with the highest hazard (4 to 6 times) for each outcome. In multimarker models, independent associations were observed for the primary outcome (MR-proANP and NT-proBNP), HF-hospitalization and cardiovascular admission (MR-proANP only), and all-cause mortality (NT-proBNP only) (P < 0.05). The discriminative value of MR-proANP was superior to BNP/NT-proBNP (HF-hospitalization) and BNP (primary outcome) (P < 0.05).

CONCLUSIONS

MR-proANP was not inappropriately low relative to concurrent BNP/NT-proBNP values. Proportional increments in MR-proANP were more pronounced than for B-peptides for given decrements in cardiac structure/function. MR-proANP offered greater independent predictive power overall.

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.

Sacubitril/valsartan attenuates atrial conduction disturbance and electrophysiological heterogeneity with ameliorating fibrosis in mice

Background

Sacubitril/valsartan (SacVal) has been shown to improve the prognosis of heart failure; however, whether SacVal reduces the occurrence of atrial fibrillation (AF) in heart failure has not yet been elucidated. In this study, we aimed to determine whether SacVal is effective in reducing the occurrence of AF in heart failure and identify the underlying mechanism of its electrophysiological effect in mice.

Methods

Adult male mice underwent transverse aortic constriction, followed by SacVal, valsartan, or vehicle treatment for two weeks. Electrophysiological study (EPS) and optical mapping were performed to assess the susceptibility to AF and the atrial conduction properties, and fibrosis was investigated using heart tissue and isolated cardiac fibroblasts (CFs).

Results

EPS analysis revealed that AF was significantly less inducible in SacVal-treated mice than in vehicle-treated mice. Optical mapping of the atrium showed that SacVal-treated and valsartan-treated mice restored the prolonged action potential duration (APD); however, only SacVal-treated mice showed the restoration of decreased conduction velocity (CV) compared to vehicle-treated mice. In addition, the electrophysiological distribution analysis demonstrated that heterogeneous electrophysiological properties were rate-dependent and increased heterogeneity was closely related to the susceptibility to AF. SacVal attenuated the increased heterogeneity of CV at short pacing cycle length in atria, whereas Val could not. Histological and molecular evaluation showed that SacVal exerted the anti-fibrotic effect on the atria. An in vitro study of CFs treated with natriuretic peptides and LBQ657, the metabolite and active form of sacubitril, revealed that C-type natriuretic peptide (CNP) combined with LBQ657 had an additional anti-fibrotic effect on CFs.

Conclusions

Our results demonstrated that SacVal can improve the conduction disturbance and heterogeneity through the attenuation of fibrosis in murine atria and reduce the susceptibility of AF in heart failure with pressure overload, which might be attributed to the enhanced function of CNP.

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.

Risk stratification for worsening renal function and renal decline in heart failure patients with reduced ejection fraction after sacubitril/valsartan treatment

BACKGROUND

In the real-world setting, data regarding renal decline following sacubitril/valsartan treatment are lacking. This study aimed to develop a scoring system to predict renal outcome in sacubitril/valsartan-treated patients.

METHODS

Between 2017 and 2018, a total of 1505 heart failure patients with reduced ejection fraction (HFrEF) undergoing sacubitril/valsartan treatment were consecutively enrolled from 10 hospitals to serve as the derivation cohort. Another 1620 HFrEF patients receiving sacubitril/valsartan were included as the validation cohort. Worsening renal function (WRF) was defined as a serum creatinine increase of >0.3 mg/dL and/or >25 % at 8 months of sacubitril/valsartan treatment. The derivation cohort was used to identify independent predictive factors for WRF through multivariate analysis, which were then used to develop the risk score system.

RESULTS

Among the 3125 HFrEF patients, 689 (22.0 %) patients had WRF at 8 months following sacubitril/valsartan treatment. In the derivation cohort, six prognostic factors (age, functional class, history of peripheral arterial disease, diabetes mellitus, gout or hyperuricemia, and serum albumin level) were independently associated with WRF, and were combined into a risk predicting score. This score showed accurate discrimination in the derivation and validation cohorts (Harrell's concordance indexes 0.74 and 0.71, 95 % confidence intervals 0.71-0.78 and 0.69-0.74, respectively). Patients with a higher risk score experienced a more rapid decline in renal function, poorer clinical outcomes, and a higher rate of discontinuation of sacubitril/valsartan treatment.

CONCLUSIONS

This study developed a score for WRF after sacubitril/valsartan treatment, which may assist clinicians with risk stratification and therapeutic decision-making.

Importance of the 'area under the curve' from serial NT-proBNP measurements during treatment with sacubitril/valsartan

AIMS

Serial assessment of natriuretic peptides is widely utilized in heart failure clinics. Uncertainty exists regarding the value of multiple natriuretic peptide measurements and how they might be best interpreted.

METHODS AND RESULTS

Six hundred thirty-two patients with heart failure with reduced ejection fraction (<40%) and complete biomarker data were enrolled to receive sacubitril/valsartan. Patients underwent periodic study visits during 1-year follow-ups. Echocardiographic data and cardiac biomarkers, including N-terminal pro-B-type natriuretic peptide (NT-proBNP) were collected during study visits. Patients were categorized into three groups based on tertiles of baseline NT-proBNP levels. The area under the curve (AUC) of NT-proBNP measurements across study visits was calculated. Compared with patients with higher AUC (and thus higher concentrations over a longer period of time), those with lower AUC were younger, had a lower prevalence of chronic kidney disease, prior coronary artery bypass graft, atrial fibrillation, and higher body-mass index. A significant interaction existed between baseline NT-proBNP and subsequent AUC for predicting LVEF change across visits (P-value < 0.001): among those with lower baseline NT-proBNP, similar improvements in left ventricular (LV) volumes LV ejection fraction, and LV mass index were observed across subsequent AUC (P-value > 0.1). However, among those with higher baseline NT-proBNP, those with lower subsequent AUC had a greater improvement in cardiac remodelling indices (P-value < 0.05).

CONCLUSIONS

Serial NT-proBNP monitoring (integrating the totality of measurements as an AUC) during treatment with sacubitril/valsartan informs unique information regarding the future changes in cardiac remodelling indices, especially among those with higher NT-proBNP levels at baseline.

Effect of sacubitril/valsartan on brain natriuretic peptide level and prognosis of acute cerebral infarction

BACKGROUND AND PURPOSE

Previous studies demonstrated that elevated brain natriuretic peptide (BNP) level is associated with adverse clinical outcomes of acute cerebral infarction (ACI). Researchers hypothesized that BNP might be a potential neuroprotective factor against cerebral ischemia because of the antagonistic effect of the natriuretic peptide system on the renin-angiotensin system and regulation of cardiovascular homeostasis. However, whether decreasing the BNP level can improve the prognosis of ACI has not been studied yet. The main effect of sacubitril/valsartan is to enhance the natriuretic peptide system. We investigated whether the intervention of plasma BNP levels with sacubitril/valsartan could improve the prognosis of patients with ACI.

METHODS

In a randomized, controlled, parallel-group trial of patients with ACI within 48 hours of symptom onset and need for antihypertensive therapy, patients have randomized within 24 hours to sacubitril/valsartan 200mg once daily (the intervention group) or to conventional medical medication (the control group). The primary outcome was a change in plasma BNP levels before and after sacubitril/valsartan administration. The secondary outcomes included plasma levels of brain-derived neurotrophic factor (BDNF), Corin and neprilysin (NEP) before and after medication, the modified Rankin scale, and the National Institutes of Health Stroke Scale (at onset, at discharge, 30 days, and 90 days after discharge).

RESULTS

We evaluated 80 eligible patients admitted to the Stroke Center of Lianyungang Second People's Hospital between 1st May, 2021 and 31st June, 2022. Except for 28 patients excluded before randomization and 14 patients who did not meet the criteria or dropped out or lost to follow-up during the trial, the remaining 38 patients (intervention group: 17, control group: 21) had well-balanced baseline features. In this trial, we found that plasma BNP levels (P = 0.003) decreased and NEP levels (P = 0.006) increased in enrolled patients after treatment with sacubitril/valsartan. There were no differences in plasma BDNF and Corin levels between the two groups. Furthermore, no difference in functional prognosis was observed between the two groups (all P values>0.05).

CONCLUSIONS

Sacubitril/valsartan reduced endogenous plasma BNP levels in patients with ACI and did not affect their short-term prognosis.

Sacubitril/valsartan mitigates cardiac remodeling, systolic dysfunction, and preserves mitochondrial quality in a rat model of mitral regurgitation

Sacubitril/valsartan (SAC/VAL), an angiotensin receptor blocker-neprilysin inhibitor, has been widely used to treat several types of heart failure. Nevertheless, the effects of drugs in mitral regurgitation patients, from the molecular level to therapeutic effects, remain unclear. This study investigates the roles of SAC/VAL on cardiac function, mitochondrial quality, autophagy, mitophagy, and natriuretic peptides in a rat model of chronic mitral regurgitation. Male Sprague-Dawley rats underwent MR induction (n = 16) and sham surgeries (n = 8). Four weeks post-surgery confirmed MR rats were randomly divided into MR (n = 8) and SAC/VAL (n = 8) groups. The SAC/VAL group was administered SAC/VAL, whereas the MR and the sham rats received vehicle via oral gavage daily for 8 weeks. Cardiac geometry, function, and myocardial fibrosis were assessed by echocardiography and histopathology. Spectrophotometry and real-time PCR were performed to assess the pharmacological effects on mitochondrial quality, autophagy, mitophagy, and natriuretic peptides. MR rats demonstrated significant left heart dilation and left ventricular systolic dysfunction compared with the sham group, which could be significantly improved by SAC/VAL. In addition, SAC/VAL significantly reduced myocardial cardiac remodeling and fibrosis in MR rats. SAC/VAL improved the mitochondrial quality by attenuating mitochondrial reactive oxygen species production and mitochondrial depolarization compared with the MR group. Also, the upregulation of autophagy-related, mitophagy-related, and natriuretic peptide system gene expression in MR rats was attenuated by SAC/VAL treatment. In conclusion, this study demonstrated that SAC/VAL treatment could provide numerous beneficial effects in MR conditions, suggesting that this drug may be an effective treatment for MR.

Biomarkers for the Diagnosis of Heart Failure in People with Diabetes: A Consensus Report from Diabetes Technology Society

Diabetes Technology Society assembled a panel of clinician experts in diabetology, cardiology, clinical chemistry, nephrology, and primary care to review the current evidence on biomarker screening of people with diabetes (PWD) for heart failure (HF), who are, by definition, at risk for HF (Stage A HF). This consensus report reviews features of HF in PWD from the perspectives of 1) epidemiology, 2) classification of stages, 3) pathophysiology, 4) biomarkers for diagnosing, 5) biomarker assays, 6) diagnostic accuracy of biomarkers, 7) benefits of biomarker screening, 8) consensus recommendations for biomarker screening, 9) stratification of Stage B HF, 10) echocardiographic screening, 11) management of Stage A and Stage B HF, and 12) future directions. The Diabetes Technology Society panel recommends 1) biomarker screening with one of two circulating natriuretic peptides (B-type natriuretic peptide or N-terminal prohormone of B-type natriuretic peptide), 2) beginning screening five years following diagnosis of type 1 diabetes (T1D) and at the diagnosis of type 2 diabetes (T2D), 3) beginning routine screening no earlier than at age 30 years for T1D (irrespective of age of diagnosis) and at any age for T2D, 4) screening annually, and 5) testing any time of day. The panel also recommends that an abnormal biomarker test defines asymptomatic preclinical HF (Stage B HF). This diagnosis requires follow-up using transthoracic echocardiography for classification into one of four subcategories of Stage B HF, corresponding to risk of progression to symptomatic clinical HF (Stage C HF). These recommendations will allow identification and management of Stage A and Stage B HF in PWD to prevent progression to Stage C HF or advanced HF (Stage D HF).

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.

Effects of sacubitril-valsartan on central and obstructive apneas in heart failure patients with reduced ejection fraction

OBJECTIVE

This study aimed to evaluate the effect of sacubitril-valsartan (SV) on central apneas (CA) and obstructive apneas (OA) in patients with heart failure with reduced ejection fraction (HFrEF).

METHODS

In patients with HFrEF, SV initiation was titrated to the highest tolerable dosage. Patients were evaluated with portable apnea monitoring, echocardiography, and cardiopulmonary exercise testing at baseline and 3 months later.

RESULTS

Of a total of 18 patients, 9 (50%) had OA, 7 (39%) had CA, and 2 (11%) had normal breathing. SV therapy was related to a reduction in NT-pro BNP and an improvement in LV function after 3 months. Portable apnea monitoring revealed a significant decrease of the respiratory event index (REI) after treatment with SV (20 ± 23 events/h to 7 ± 7 events/h, p = 0.003). When subgrouping according to type of apneas, REI, and time spent below 90% saturation (T90) decreased in patients with CA and OA (all p < 0.05).

CONCLUSION

In this prospective study, SV treatment for 3 months in patients with CA and OA is associated with a significant decrease in REI.

CNP Promotes Antiarrhythmic Effects via Phosphodiesterase 2

BACKGROUND

Ventricular arrhythmia and sudden cardiac death are the most common lethal complications after myocardial infarction. Antiarrhythmic pharmacotherapy remains a clinical challenge and novel concepts are highly desired. Here, we focus on the cardioprotective CNP (C-type natriuretic peptide) as a novel antiarrhythmic principle. We hypothesize that antiarrhythmic effects of CNP are mediated by PDE2 (phosphodiesterase 2), which has the unique property to be stimulated by cGMP to primarily hydrolyze cAMP. Thus, CNP might promote beneficial effects of PDE2-mediated negative crosstalk between cAMP and cGMP signaling pathways.

METHODS

To determine antiarrhythmic effects of cGMP-mediated PDE2 stimulation by CNP, we analyzed arrhythmic events and intracellular trigger mechanisms in mice in vivo, at organ level and in isolated cardiomyocytes as well as in human-induced pluripotent stem cell-derived cardiomyocytes.

RESULTS

In ex vivo perfused mouse hearts, CNP abrogated arrhythmia after ischemia/reperfusion injury. Upon high-dose catecholamine injections in mice, PDE2 inhibition prevented the antiarrhythmic effect of CNP. In mouse ventricular cardiomyocytes, CNP blunted the catecholamine-mediated increase in arrhythmogenic events as well as in I_CaL, I_NaL, and Ca²⁺ spark frequency. Mechanistically, this was driven by reduced cellular cAMP levels and decreased phosphorylation of Ca²⁺ handling proteins. Key experiments were confirmed in human iPSC-derived cardiomyocytes. Accordingly, the protective CNP effects were reversed by either specific pharmacological PDE2 inhibition or cardiomyocyte-specific PDE2 deletion.

CONCLUSIONS

CNP shows strong PDE2-dependent antiarrhythmic effects. Consequently, the CNP-PDE2 axis represents a novel and attractive target for future antiarrhythmic strategies.

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.

Mechanisms of current therapeutic strategies for heart failure: more questions than answers?

Heart failure (HF) is a complex, multifactorial and heterogeneous syndrome with substantial mortality and morbidity. Over the last few decades, numerous attempts have been made to develop targeted therapies that may attenuate the known pathophysiological pathways responsible for causing the progression of HF. However, therapies developed with this objective have sometimes failed to show benefit. The pathophysiological construct of HF with numerous aetiologies suggests that interventions with broad mechanisms of action which simultaneously target more than one pathway maybe more effective in improving the outcomes of patients with HF. Indeed, current therapeutics with clinical benefits in HF have targeted a wider range of intermediate phenotypes. Despite extensive scientific breakthroughs in HF research recently, questions persist regarding the ideal therapeutic targets which may help achieve maximum benefit. In this review, we evaluate the mechanism of action of current therapeutic strategies, the pathophysiological pathways they target and highlight remaining knowledge gaps regarding the mode of action of these interventions.

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.

Real-World Experience of Angiotensin Receptor-Neprilysin Inhibition in Reduced Ejection Fraction Heart Failure Patients With Advanced Kidney Disease

OBJECTIVE

To investigate the effectiveness and safety of angiotensin receptor-neprilysin inhibitors (ARNIs) in real-world patients with heart failure with reduced ejection fraction (HFrEF) and advanced chronic kidney disease (estimated glomerular filtration rate [eGFR] < 30 mL/min per 1.73 m²), which have been excluded from the landmark trials.

PATIENTS AND METHODS

This study examined 3281 patients pooled from two multicenter HFrEF cohorts, and 661 patients with baseline eGFR less than 30 mL/min per 1.73 m² were further analyzed (the Taiwan Society of Cardiology - Heart Failure with reduced Ejection Fraction (TSOC-HFrEF) registry: May 1, 2013 to October 31, 2014, and the Treatment with Angiotensin Receptor neprilysin inhibitor fOr Taiwan Heart Failure patients (TAROT-HF) study: March 1, 2017, to December 31, 2018). Propensity score matching was performed to adjust for confounders. At 1-year follow-up, all-cause mortality, total heart failure hospitalizations, renal function, and left ventricular ejection fraction (LVEF) were used as the endpoints.

RESULTS

After propensity score matching, 510 patients (age, 69.8±13.9 years; male, 61.0%; mean LVEF, 29.8±7.3%; mean eGFR, 19.8±9.0 mL/min per 1.73 m²) were included in the final analysis, including 278 patients receiving ARNI treatment (ARNI group) and 232 patients not on ARNI treatment (non-ARNI group). Baseline characteristics were comparable between the two groups. At 1 year, eGFR and LVEF measurements were significantly higher in the ARNI group than in the non-ARNI group (25.0±17.1 mL/min per 1.73 m² vs 21.4±17.5 mL/min per 1.73 m²; P=.04; and 40.1±12.9% vs. 33.1±10.8%, P<.001, respectively). The ARNI group had significantly lower risks of 1-year all-cause mortality (19.4 vs 30.9 per 100-person year; P=.02), and total HF rehospitalizations (70.0 vs 110.4 per 100-person year; P=.01) than non-ARNI users.

CONCLUSION

Our results show the effectiveness of ARNIs in HFrEF patients with advanced chronic kidney disease in a real-world setting.

Role of Cardiac Natriuretic Peptides in Heart Structure and Function

Cardiac natriuretic peptides (NPs), atrial NP (ANP) and B-type NP (BNP) are true hormones produced and released by cardiomyocytes, exerting several systemic effects. Together with C-type NP (CNP), mainly expressed by endothelial cells, they also exert several paracrine and autocrine activities on the heart itself, contributing to cardiovascular (CV) health. In addition to their natriuretic, vasorelaxant, metabolic and antiproliferative systemic properties, NPs prevent cardiac hypertrophy, fibrosis, arrhythmias and cardiomyopathies, counteracting the development and progression of heart failure (HF). Moreover, recent studies revealed that a protein structurally similar to NPs mainly produced by skeletal muscles and osteoblasts called musclin/osteocrin is able to interact with the NPs clearance receptor, attenuating cardiac dysfunction and myocardial fibrosis and promoting heart protection during pathological overload. This narrative review is focused on the direct activities of this molecule family on the heart, reporting both experimental and human studies that are clinically relevant for physicians.

Efficacy and Dosage Pattern of Sacubitril/Valsartan in Chinese Heart Failure with Reduced Ejection Fraction Patients

This study aims to investigate the dosage pattern, efficacy, and safety of sacubitril/valsartan (Sac/Val) in Chinese heart failure with reduced ejection fraction (HFrEF) patients regarding real-world settings. Patients from 27 centers with a confirmed diagnosis of HFrEF and initiated Sac/Val treatment were enrolled. The primary objective was to evaluate the dosage pattern and change of heart failure status. In a final cohort of 983 patients, outpatient Sac/Val treatment demonstrated a similar beneficial effect in NT-proBNP and cardiac function. After initiating the treatment, overall and sub-population showed similar safety and efficacy. Patients who received a higher dose of Sac/Val (> 200 mg/d) demonstrated better improvement in LV function and reduction of NT-proBNP regardless of adjustment. Among Chinese HFrEF patients, Sac/Val showed a comparable reduction in NT-proBNP and improvement in cardiac function. Data further support guideline recommendations of Sac/Val in Chinese population. Optimal up-titration might provide further benefits. Further long-term and prognostic studies are needed.

Comparative Effect of Angiotensin Receptor Neprilysin Inhibition on B-type Natriuretic Peptide Levels Measured by Three Different Assays: The PROVE-HF Study

Background

Several different B-type natriuretic peptide (BNP) assays are used clinically for diagnostic and prognostic evaluation of heart failure (HF). BNP binds weakly to neprilysin and is cleaved in multiple areas adjacent to the binding sites for the antibodies used in these immunoassays. We assessed the changes in BNP following neprilysin inhibition as measured by 3 immunoassays that recognize different epitopes.

Methods

Among 130 participants with HF with reduced ejection fraction, blood was collected prior to treatment with sacubitril/valsartan (sac/val) and then repeatedly measured through 52 weeks of treatment. BNP concentrations were measured with 3 widely used BNP assays (Siemens, Abbott, and Quidel).

Results

Study participants had a mean age of 65 ± 13 years and 76% were men. The median BNP concentration at baseline was 133 ng/L by the Siemens assay, 127 ng/L by the Abbott assay, and 141 ng/L by the Quidel assay. Following initiation of sac/val, there were significantly greater declines in BNP measured by Quidel and Abbott (P = 0.009 and P &lt; 0.001), respectively (both with N-terminal capture antibodies), compared to Siemens (with C-terminal capture antibodies). The difference from baseline was not statistically significant until after week 12 (mean –10.1% for Quidel and –14.3% for Abbott) compared to non-significant differences before 12 weeks (mean –4.5% for Quidel and –6.0% for Abbott).

Conclusions

Following initiation of sac/val, BNP measurements may modestly differ depending on the assay method used, particularly after a few months of treatment. Whether these differences relate to neprilysin-mediated degradation of antibody binding sites deserves further study.

Study registration

PROVE-HF ClinicalTrials.gov Identifier: NCT02887183.

Natriuretic peptide pathways in heart failure: further therapeutic possibilities

The discovery of the heart as an endocrine organ resulted in a remarkable recognition of the natriuretic peptide system (NPS). Specifically, research has established the production of atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) from the heart, which exert pleiotropic cardiovascular, endocrine, renal, and metabolic actions via the particulate guanylyl cyclase A receptor (GC-A) and the second messenger, cGMP. C-type natriuretic peptide (CNP) is produced in the endothelium and kidney and mediates important protective auto/paracrine actions via GC-B and cGMP. These actions, in part, participate in the efficacy of sacubitril/valsartan in heart failure (HF) due to the augmentation of the NPS. Here, we will review important insights into the biology of the NPS, the role of precision medicine, and focus on the phenotypes of human genetic variants of ANP and BNP in the general population and the relevance to HF. We will also provide an update of the existence of NP deficiency states, including in HF, which provide the rationale for further therapeutics for the NPS. Finally, we will review the field of peptide engineering and the development of novel designer NPs for the treatment of HF. Notably, the recent discovery of a first-in-class small molecule GC-A enhancer, which is orally deliverable, will be highlighted. These innovative designer NPs and small molecule possess enhanced and novel properties for the treatment of HF and cardiovascular diseases.

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.

CNP, the Third Natriuretic Peptide: Its Biology and Significance to the Cardiovascular System

Simple Summary

CNP is the third natriuretic peptide to be isolated and is widely expressed in the central nervous system, osteochondral system, and vascular system. The receptor that is mainly targeted by CNP is GC-B, which differs from GC-A, the receptor targeted by the other two natriuretic peptides, ANP and BNP. Consequently, the actions of CNP differ somewhat from those of ANP and BNP. Research into the actions of CNP has shown that CNP attenuates cardiac remodeling in animal models of cardiac hypertrophy, myocardial infarction, and myocarditis. Studies examining CNP/GC-B signaling showed that it contributes to the prevention of cardiac stiffness. Endogenous CNP, perhaps acting in part through CNP/NPR-C signaling, contributes to the regulation of vascular function and blood pressure. CNP regulates vascular remodeling and angiogenesis via CNP/GC-B/CGK signaling. CNP attenuates interstitial fibrosis and fibrosis-related gene expression in pressure overload and myocardial infarction models. The clinical application of CNP as a therapeutic agent for cardiovascular diseases is anticipated.

Abstract

The natriuretic peptide family consists of three biologically active peptides: ANP, BNP, and CNP. CNP is more widely expressed than the other two peptides, with significant levels in the central nervous system, osteochondral system, and vascular system. The receptor that is mainly targeted by CNP is GC-B, which differs from GC-A, the receptor targeted by ANP and BNP. Consequently, the actions of CNP differ somewhat from those of ANP and BNP. CNP knockout leads to severe dwarfism, and there has been important research into the role of CNP in the osteochondral system. As a result, a CNP analog is now available for clinical use in patients with achondroplasia. In the cardiovascular system, CNP and its downstream signaling are involved in the regulatory mechanisms underlying myocardial remodeling, cardiac function, vascular tone, angiogenesis, and fibrosis, among others. This review focuses on the roles of CNP in the cardiovascular system and considers its potential for clinical application in the treatment of cardiovascular diseases.

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.

High sensitivity Troponins In Patients with elevated prohormone of beta natriuretic peptide and acute heart failure (HIGH TRIP Trial)

In patients presented to emergency rooms, Pro hormone of Natriuretic Peptide (Pro BNP) essay is overly sensitive test to rule out heart failure but less specific in predicting outcomes in follow-ups, in this study we ought to find the added value of High Sensitivity cardiac Troponin I (Hs-cTn I), in patients presented acutely with heart failure and its impact on mortality when Pro BNP is highly elevated. Prospective cohort study, inclusion criteria were age above 18 and clearly positive NT Pro BNP > 1000 pg/ml, with 12 months follow up period, primary end point was mortality from heart failure, secondary endpoint was need for rehospitalization. 95 patients were enrolled, divided into overt and non-overt pulmonary edema groups. Mean (Pro BNP) was 6184 and 5927 pg/ml and mean (Hs-cTn I) were 19.27 and 0.17 ng/ml respectively, Mean Ejection fraction was 48 ± 7 and 47 ± 7 for each group sequentially. Mortality rate was 4 (13%) in the higher Hs-c Tn I group, and 1 (1.6%) in the low troponin level group p = .03, odd ratio was 8.5, 95% CI (0.9-80). Need for re-hospitalization was present in 12 (38%) Vs 7 (8%) patients, p = .0081, odd ratio 4.8, 95% CI (1.7-14.2). In COX proportional hazard analysis, only Hs-cTn I was a significant predictor of poor outcome in this high-risk cohort with p = 0.0001. Adding (Hs-cTrop I) assay to the panel of laboratory testing, in patients presented to ER with acute heart failure and with high Pro-BNP > 1000, may further predicts mortality and rehospitalization rate.

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.

The Efficacy and Safety of Sacubitril/Valsartan in Heart Failure Patients: A Review

Heart failure (HF) is one of the leading causes of morbidity and mortality worldwide. Sacubitril/valsartan, an angiotensin receptor-neprilysin inhibitor, has been approved for the treatment of HF. At present, there have been few systematic and detailed reviews discussing the efficacy and safety of sacubitril/valsartan in HF. In this review, we first introduced the pharmacological mechanisms of sacubitril/valsartan, including the reduction in the degradation of natriuretic peptides in the natriuretic peptide system and inhibition of the renin-angiotensin system. Then, we summarized the efficacy of sacubitril/valsartan in HF patients with reduced ejection fraction (HFrEF) or preserved ejection fraction (HFpEF) including the reduction in risks of mortality and hospitalization, reversal of cardiac remodeling, regulation of biomarkers of HF, improvement of the quality of life, antiarrhythmia, improving renal dysfunction and regulation of metabolism. Finally, we discussed the safety and tolerability of sacubitril/valsartan in the treatment of HFrEF or HFpEF. Compared with ACEIs/ARBs or placebo, sacubitril/valsartan showed good safety and tolerability, although the risk of hypotension might be high. In conclusion, the overwhelming majority of studies show that sacubitril/valsartan is effective and safe in the treatment of HFrEF patients but that it has little benefit in HFpEF patients. Sacubitril/valsartan will probably be a promising anti-HF drug in the near future.

Potential effects and application prospect of angiotensin receptor-neprilysin inhibitor in diabetic kidney disease

Diabetic kidney disease (DKD) is one of the main causes of end-stage renal disease (ESRD) and all-cause mortality in diabetic patients, despite the extensive use of angiotensin-converting enzyme inhibitor (ACEI) and angiotensin II receptor blocker (ARB). Angiotensin receptor-neprilysin inhibitor (ARNI), combining ARB and neutral endopeptidase inhibitor (NEPI), is likely to have potential favorable effects in DKD. This review summarizes existing preclinical and clinical studies on mechanism of ARNI and its potential effects on DKD. In preclinical studies, ARNI manifested its renoprotective effects by improving natriuresis, ameliorating inflammation, oxidative stress and renal dysfunction, and slowing down glomerulosclerosis and tubulointerstitial injury of kidney, but its effect on proteinuria is still controversial. Beneficial effects of ARNI on blood glucose regulation and glycometabolism have also been reported. There are no clinical studies of ARNI that specifically focus on DKD patients so far. ARNI has application potential in DKD, but there still need clinical studies that focus on DKD patients to determine its effectiveness, safety and underlying mechanism.

Angiotensin receptor-neprilysin inhibitor in patients with heart failure and chronic kidney disease

Despite significant advances in the management of heart failure with reduced ejection fraction (HFrEF), there remains an enormous health problem with high morbidity and mortality over the last few decades. The neprilysin inhibitor enhances the activity of natriuretic peptides, producing vasodilation, natriuresis, and diuresis. Angiotensin receptor blockers inhibit the renin-angiotensin-aldosterone system. Sacubitril/valsartan, a first-in-class angiotensin receptor-neprilysin inhibitor (ARNI), has been shown to improve cardiovascular outcomes in HFrEF and delay the progression of chronic kidney disease (CKD) in patients with HFrEF. The PARADIGM-HF study showed a reduction in diuretic need in the ARNI group. While the use of diuretics is effective in volume control in patients with HFrEF, their use has the potential to adversely affect renal function. Therefore, ARNI therapy could benefit patients with heart failure and CKD by reducing cardiovascular morbidity and mortality and possibly retarding the progression of CKD, although more clinical evidence is required in patients with severe CKD and end-stage renal disease.

Efficacy and Safety of Dapagliflozin in Heart Failure With Reduced Ejection Fraction According to N-Terminal Pro-B-Type Natriuretic Peptide: Insights From the DAPA-HF Trial

BACKGROUND

Effective therapies for HFrEF usually reduce NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels, and it is important to establish whether new treatments are effective across the range of NT-proBNP.

METHODS

We evaluated both these questions in the DAPA-HF (Dapagliflozin and Prevention of Adverse Outcomes in Heart Failure) trial. Patients in New York Heart Association functional class II to IV with a left ventricular ejection fraction ≤40% and a NT-proBNP level ≥600 pg/mL (≥600 ng/L; ≥400 pg/mL if hospitalized for HF within the previous 12 months or ≥900 pg/mL if atrial fibrillation/flutter) were eligible. The primary outcome was the composite of an episode of worsening HF or cardiovascular death.

RESULTS

Of the 4744 randomized patients, 4742 had an available baseline NT-proBNP measurement (median, 1437 pg/mL [interquartile range, 857-2650 pg/mL]). Compared with placebo, treatment with dapagliflozin significantly reduced NT-proBNP from baseline to 8 months (absolute least-squares mean reduction, -303 pg/mL [95% CI, -457 to -150 pg/mL]; geometric mean ratio, 0.92 [95% CI, 0.88-0.96]). Dapagliflozin reduced the risk of worsening HF or cardiovascular death, irrespective of baseline NT-proBNP quartile; the hazard ratio for dapagliflozin versus placebo, from lowest to highest quartile was 0.43 (95% CI, 0.27-0.67), 0.77 (0.56-1.04), 0.78 (0.60-1.01), and 0.78 (0.64-0.95); P for interaction=0.09. Consistent benefits were observed for all-cause mortality. Compared with placebo, dapagliflozin increased the proportion of patients with a meaningful improvement (≥5 points) in Kansas City Cardiomyopathy Questionnaire total symptom score (P for interaction=0.99) and decreased the proportion with a deterioration ≥5 points (P for interaction=0.87) across baseline NT-proBNP quartiles.

CONCLUSIONS

In patients with HFrEF, dapagliflozin reduced NT-proBNP by 300 pg/mL after 8 months of treatment compared with placebo. In addition, dapagliflozin reduced the risk of worsening HF and death, and improved symptoms, across the spectrum of baseline NT-proBNP levels included in DAPA-HF. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03036124.

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.

Toward a New Paradigm for Targeted Natriuretic Peptide Enhancement in Heart Failure

The natriuretic peptide system (NPS) plays a fundamental role in maintaining cardiorenal homeostasis, and its potent filling pressure-regulated diuretic and vasodilatory effects constitute a beneficial compensatory mechanism in heart failure (HF). Leveraging the NPS for therapeutic benefit in HF has been the subject of intense investigation during the last three decades and has ultimately reached widespread clinical use in the form of angiotensin receptor-neprilysin inhibition (ARNi). NPS enhancement via ARNi confers beneficial effects on mortality and hospitalization in HF, but inhibition of neprilysin leads to the accumulation of a number of other vasoactive peptides in the circulation, often resulting in hypotension and raising potential concerns over long-term adverse effects. Moreover, ARNi is less effective in the large group of HF patients with preserved ejection fraction. Alternative approaches for therapeutic augmentation of the NPS with increased specificity and efficacy are therefore warranted, and are now becoming feasible particularly with recent development of RNA therapeutics. In this review, the current state-of-the-art in terms of experimental and clinical strategies for NPS augmentation and their implementation will be reviewed and discussed.

Active B-Type Natriuretic Peptide Measured by Mass Spectrometry and Response to Sacubitril/Valsartan

BACKGROUND

B-type natriuretic peptide (BNP) immunoassays (BNPia) do not differentiate active and inactive forms. Inactive NT-proBNP is used to track heart failure (HF) during treatment with sacubitril/valsartan, which inhibits BNP degradation. Mass spectrometry (MS) may better assess effects of HF treatment on biologically active BNP1-32.

METHODS AND RESULTS

We developed a MS assay with immediate protease inhibition to quantify BNP1-32 over a linear range, using labeled recombinant BNP standard. In 4 healthy volunteers, BNP1-32 by MS (BNPMS) increased from below the 5 pg/mL detection limit to 228 pg/mL after nesiritide. In patients with HF, BNPMS was measured in parallel with BNP and NT-proBNP immunoassays before and during sacubitril/valsartan treatment. BNPMS was 4.4-fold lower than BNPia in patients with HF. Among patients not taking sacubitril/valsartan and without end-stage renal disease, BNPMS correlated with BNPia (rs = 0.77, P < .001) and NT-proBNP (rs = 0.74, P < .001). After a median of 8 weeks on sacubitril/valsartan, active BNPMS levels decreased by 50% (interquartile range -98.3% to 41.7%, n = 22, P = .048) and correlated with NT-proBNP (rs = 0.64, P < .001), but not with BNPia (rs = 0.46, P = .057).

CONCLUSIONS

Active BNP measured by MS accounts for only a small amount of BNP measured by immunoassays. Although decreased BNP production was anticipated to be masked by inhibition of degradation, levels of active BNP decreased during chronic sacubitril/valsartan treatment.

A Contemporary View of Natriuretic Peptides in the SARS-CoV-2 Era

The heart releases natriuretic peptides (NPs) which represent an important hormonal axis with cardiorenal protective effects. In view of their properties, NPs have pathophysiologic, diagnostic and prognostic implications in several cardiovascular diseases (CVDs). Severe pulmonary inflammation, as induced by the SARS-COV2, may increase pulmonary pressure with potential influence on NPs release, whereby normal cardiovascular integrity becomes impaired. Moreover, pre-existing CVDs are strong negative prognostic factors since they exacerbate the effects of the viral infection and lead to worse outcomes. In this context, it may be expected that NPs exert a key protective role toward the virus infection whereas an impairment of NPs release contributes to the virus deleterious effects. In this review article we explore the potential involvement of NPs in the COVID-19 disease. To this aim, we will first focus on the interactions between NPs and the Ang II/ATIR arm of the renin-angiotensin-aldosterone system (RAAS) as well as with the protective ACE2/Ang (1-7) arm of the RAAS. Subsequently, we will review evidence that strongly supports the role of increased NT-proBNP level as a marker of cardiac damage and of worse prognosis in the COVID-19 affected patients. Finally, we will discuss the potential therapeutic benefits of these protective hormones toward the viral infection through their endothelial protective function, anti-inflammatory and anti-thrombotic effects. In conclusion, the potential implications of NPs in the SARS-CoV-2 infection, as discussed in our article, represent an important issue that deserves to be fully investigated.