Cardioprotective Effects of LCZ696 (Sacubitril/Valsartan) After Experimental Acute Myocardial Infarction

Von Willebrand factor exacerbates heart failure through formation of neutrophil extracellular traps

BACKGROUND AND AIMS

Heart failure (HF) is a leading cause of mortality worldwide and characterized by significant co-morbidities and dismal prognosis. Neutrophil extracellular traps (NETs) aggravate inflammation in various cardiovascular diseases; however, their function and mechanism of action in HF pathogenesis remain underexplored. This study aimed to investigate the involvement of a novel VWF-SLC44A2-NET axis in HF progression.

METHODS

NET levels were examined in patients with HF and mouse models of transverse aortic constriction (TAC) HF. PAD4 knockout mice and NET inhibitors (GSK-484, DNase I, NEi) were used to evaluate the role of NETs in HF. RNA sequencing was used to investigate the downstream mechanisms. Recombinant human ADAMTS13 (rhADAMTS13), ADAMTS13, and SLC44A2 knockouts were used to identify novel upstream factors of NETs.

RESULTS

Elevated NET levels were observed in patients with HF and TAC mouse models of HF. PAD4 knockout and NET inhibitors improved the cardiac function. Mechanistically, NETs induced mitochondrial dysfunction in cardiomyocytes, inhibiting mitochondrial biogenesis via the NE-TLR4-mediated suppression of PGC-1α. Furthermore, VWF/ADAMTS13 regulated NET formation via SLC44A2. Additionally, sacubitril/valsartan amplifies the cardioprotective effects of the VWF-SLC44A2-NET axis blockade.

CONCLUSIONS

This study established the role of a novel VWF-SLC44A2-NET axis in regulating mitochondrial homeostasis and function, leading to cardiac apoptosis and contributing to HF pathogenesis. Targeting this axis may offer a potential therapeutic approach for HF treatment.

Blunted increase in plasma BNP during acute coronary syndrome attacks in obese patients

Background

Unexpectedly low natriuretic peptide (NP) levels in proportion to heart failure severity are often observed in obese individuals. However, the magnitude of NP elevation in response to acute cardiac stress in obesity has not yet been extensively studied. This study aimed to determine the impact of obesity on the increase in plasma NP in response to cardiac hemodynamic stress during acute coronary syndrome (ACS) attacks.

Methods and Results

The study population included 557 consecutive patients with ACS for whom data were collected during emergency cardiac catheterization. To determine the possible impact of body mass index (BMI) on the relationship between left ventricular ejection fraction (LVEF) and plasma B-type NP (BNP) levels, the study population was divided into two groups (Group 1: BMI <25, Group 2: BMI ≥25 [kg/m2]). Both BMI and LVEF were significantly and negatively correlated with BNP. Although a significant negative correlation between LVEF and BNP was observed in both groups, the regression line of Group 2 was significantly less steep than that of Group 1. Accordingly, BNP/LVEF ratio in Group 2, which indicates the extent of BNP increase in response to LVEF change, was significantly lower than that in Group 1.

Conclusions

Blunted increase in plasma BNP in response to cardiac hemodynamic stress during ACS attacks was observed in obese individuals. In addition to the relatively low plasma BNP levels at baseline in obese individuals, the blunted response of BNP elevation to ACS attacks may have important pathophysiological implications for hemodynamic regulation and myocardial energy metabolism.

Sacubitril/valsartan alleviates myocardial infarction-induced inflammation in mice by promoting M2 macrophage polarisation via regulation of PI3K/Akt pathway

BACKGROUND

Macrophage polarisation-mediated inflammation plays a critical role in ventricular remodelling after myocardial infarction (MI). Sacubitril/Valsartan (Sac/Val) is an angiotensin receptor-neprilysin inhibitor that has shown beneficial effects on MI and heart failure. This study aims to further explore the mechanisms by which Sac/Val exerts its protective effects against MI.

METHODS

A mouse MI model was induced by ligating the left anterior descending coronary artery, followed by Sac/Val administration. TTC staining and Masson trichrome staining were employed for estimating myocardial infarct size and fibrosis, respectively. The expression levels of proinflammatory factors were determined by ELISA and RT-qPCR. Flow cytometry and immunofluorescence staining were implemented to detect CD206-positive cell infiltration in mouse hearts. Western blotting was conducted to assess protein levels of Arg1, pro-fibrotic factors, and PI3K/Akt signalling-related markers.

RESULTS

Sac/Val treatment reduced myocardial infarct size and fibrosis in mice after MI. Sac/Val administration decreased proinflammatory cytokine production and facilitated M2 macrophage polarisation in MI mouse cardiac tissues. Sac/Val activated PI3K/Akt signalling in MI mouse hearts. Blocking PI3K/Akt signalling counteracted Sac/Val-mediated protective effects in MI mice.

CONCLUSION

Sac/Val ameliorates MI-induced inflammation by facilitating M2 macrophage polarisation and activating PI3K/Akt signalling.

LCZ696, an Angiotensin Receptor-Neprilysin Inhibitor, Ameliorates Endothelial Dysfunction in Diabetic C57BL/6 Mice

AIMS

LCZ696 (sacubitril/valsartan) exerts cardioprotective effects. Recent studies have suggested that it improves the endothelial function; however, the underlying mechanisms have not been thoroughly investigated. We investigated whether LCZ696 ameliorates diabetes-induced endothelial dysfunction.

METHODS

Diabetes was induced using streptozotocin in 8-week-old male C57BL/6 mice. Diabetic mice were randomly assigned to receive LCZ696 (100 mg/kg/day), valsartan (50 mg/kg/day), or a vehicle for three weeks. The endothelium-dependent and endothelium-independent vascular responses of the aortic segments were determined based on the response to acetylcholine and sodium nitroprusside, respectively. Human umbilical vein endothelial cells (HUVEC) and aortic segments obtained from C57BL/6 mice were used to perform in vitro and ex vivo experiments, respectively.

RESULTS

LCZ696 and valsartan reduced the blood pressure in diabetic mice (P＜0.05). The administration of LCZ696 (P＜0.001) and valsartan (P＜0.01) ameliorated endothelium-dependent vascular relaxation, but not endothelium-independent vascular relaxation, under diabetic conditions. LCZ696, but not valsartan, increased eNOSSer1177 (P=0.06) and Akt (P＜0.05) phosphorylation in the aorta. In HUVEC, methylglyoxal (MGO), a major precursor of advanced glycation end products, decreased eNOSSer1177 phosphorylation (P＜0.05) and increased eNOSThr495 phosphorylation (P＜0.001). However, atrial natriuretic peptide (ANP) reversed these effects. ANP also ameliorated the MGO-induced impairment of endothelium-dependent vascular relaxation in the aortic segments (P＜0.05), although L-NAME completely blocked this effect (P＜0.001).

CONCLUSION

LCZ696 ameliorated diabetes-induced endothelial dysfunction by increasing the bioavailability of ANP. Our findings suggest that LCZ696 has a vascular protective effect in a diabetic model and highlight that it may be more effective than valsartan.

Efficacy of early administration of sacubitril/valsartan after coronary artery revascularization in patients with acute myocardial infarction complicated by moderate-to-severe mitral regurgitation: a randomized controlled trial

Effects of angiotensin receptor/neprilysin inhibitors (ARNI) on ventricular remodeling in patients with heart failure, especially heart failure with reduced ejection fraction (HFrEF), are better than those of angiotensin-converting enzyme inhibitors (ACEI). Acute myocardial infarction (AMI) complicated by mitral regurgitation exacerbates ventricular remodeling and increases the risk of heart failure. There is limited evidence on the effects of early administration of ARNI in patients with AMI complicated by mitral regurgitation. The aim of this trial was to examine the effectiveness and the safety of early administration of sacubitril/valsartan after coronary artery revascularization in patients with AMI complicated by moderate-to-severe mitral regurgitation. This was a randomized, single-blind, parallel-group, controlled trial. From June 2021 to June 2022, we enrolled 142 consecutive patients with AMI complicated by moderate-to-severe mitral regurgitation and followed them for 12 months. The patients received standard treatment for AMI and were randomly assigned to receive ARNI or benazepril. The primary efficacy end points were the differences in mitral regurgitant jet area (MRJA), mitral regurgitant volume (MRV), concentration of n-terminal pro-brain natriuretic peptide (NT-proBNP), left ventricular ejection fraction (LVEF), and left ventricular end-diastolic volume and end-systolic volume (LVEDV and LVESV) between groups and within groups at baseline, 1, 3, 6, and 12 months. Secondary end points included the rates of heart failure hospitalization, all-cause mortality, refractory angina, malignant arrhythmias, recurrent myocardial infarction, and stroke. Safety end points included the rates of hyperkalemia, renal dysfunction, hypotension, angioedema, and cough. The ARNI group had significantly lower NT-proBNP levels than the benazepril group at 1 month and later (P < 0.001). MRJA and MRV significantly improved in the ARNI group compared with the benazepril group at 12 months (MRJA: - 3.21 ± 2.18 cm2 vs. - 1.83 ± 2.81 cm2, P < 0.05; MRV: - 27.22 ± 15.22 mL vs. - 13.67 ± 21.02 mL, P < 0.001). The ARNI group also showed significant reductions in LVEDV and LVESV (P < 0.05) and improvement in LVEF (P < 0.05). Secondary end point analysis showed a significantly higher rate of heart failure hospitalization in the benazepril group compared with the ARNI group (HR = 2.03, 95% CI 1.12-3.68, P = 0.021). Safety end point analysis showed a higher rate of hypotension in the ARNI group (P < 0.05). Early use of sacubitril/valsartan after coronary artery revascularization in patients with AMI complicated by moderate-to-severe mitral regurgitation can significantly reduce mitral regurgitation, improve ventricular remodeling, and decrease heart failure hospitalization. Nevertheless, caution is needed to avoid hypotension. Chinese Clinical Trial Registry (ChiCTR2100054255) registered on December 11, 2021.

Sacubitril/valsartan improves the prognosis of acute myocardial infarction: a meta-analysis

OBJECTIVE

To systematically evaluate the effect of sacubitril/valsartan (SV) on the prognosis of patients with acute myocardial infarction (AMI), and to provide evidence for expanding the clinical application of SV.

METHODS

PubMed, EMbase, Web of Science, and Cochrane Library were searched from inception to October 2023 for randomized controlled trials (RCTs) of SV in patients with AMI. The article was screened and evaluated by the Cochrane 5.1.0 bias risk assessment tool. RevMan5.3 was used for meta-analysis of the outcome indicators.

RESULTS

Ten RCTs involving 7230 patients were included. The results showed that SV increased left ventricular eject fraction ( MD  = 2.86, 95% CI [1.81-3.90], P  < 0.00001) and reduced readmission rate ( RR  = 0.46, 95% CI [0.32-0.68], P  < 0.0001), decreased N-terminal pro-brain natriuretic peptide ( MD = -477.46, 95% CI [-914.96 to -39.96], P  = 0.03), and reduced major adverse cardiovascular and cerebrovascular event (MACCE) ( RR  = 0.48, 95% CI [0.27-0.85], P  = 0.01). There was no significant difference in the rate of adverse reaction (AR) between the trial group and the control group ( RR  = 0.88, 95% CI [0.60-1.30], P  = 0.52).

CONCLUSION

SV can effectively improve the prognosis of AMI, prevent complications, and there is no significant difference in safety compared with angiotensin-converting enzyme inhibitor/angiotensin receptor blocker.

Sacubitril/Valsartan inhibits M1 type macrophages polarization in acute myocarditis by targeting C-type natriuretic peptide

Studies have shown that Sacubitril/valsartan (Sac/Val) can reduce myocardial inflammation in myocarditis mice, in addition to its the recommended treatment of heart failure. However, the underlying mechanisms of Sac/Val in myocarditis remain unclear. C-type natriuretic peptide (CNP), one of the targeting natriuretic peptides of Sac/Val, was recently reported to exert cardio-protective and anti-inflammatory effects in cardiovascular systems. Here, we focused on circulating levels of CNP in patients with acute myocarditis (AMC) and whether Sac/Val modulates inflammation by targeting CNP in experimental autoimmune myocarditis (EAM) mice as well as LPS-induced RAW 264.7 cells and bone marrow derived macrophages (BMDMs) models. Circulating CNP levels were higher in AMC patients compared to healthy controls, and these levels positively correlated with the elevated inflammatory cytokines IL-6 and monocyte count. In EAM mice, Sac/Val alleviated myocardial inflammation while augmenting circulating CNP levels rather than BNP and ANP, accompanied by reduction in intracardial M1 macrophage infiltration and expression of inflammatory cytokines IL-1β, TNF-α, and IL-6. Furthermore, Sac/Val inhibited CNP degradation and directly blunted M1 macrophage polarization in LPS-induced RAW 264.7 cells and BMDMs. Mechanistically, the effects might be mediated by the NPR-C/cAMP/JNK/c-Jun signaling pathway apart from NPR-B/cGMP/NF-κB pathway. In conclusion, Sac/Val exerts a protective effect in myocarditis by increasing CNP concentration and inhibiting M1 macrophages polarization.

Immunomodulation and immunopharmacology in heart failure

The immune system is intimately involved in the pathophysiology of heart failure. However, it is currently underused as a therapeutic target in the clinical setting. Moreover, the development of novel immunomodulatory therapies and their investigation for the treatment of patients with heart failure are hampered by the fact that currently used, evidence-based treatments for heart failure exert multiple immunomodulatory effects. In this Review, we discuss current knowledge on how evidence-based treatments for heart failure affect the immune system in addition to their primary mechanism of action, both to inform practising physicians about these pleiotropic actions and to create a framework for the development and application of future immunomodulatory therapies. We also delineate which subpopulations of patients with heart failure might benefit from immunomodulatory treatments. Furthermore, we summarize completed and ongoing clinical trials that assess immunomodulatory treatments in heart failure and present several therapeutic targets that could be investigated in the future. Lastly, we provide future directions to leverage the immunomodulatory potential of existing treatments and to foster the investigation of novel immunomodulatory therapeutics.

The Role of NAD+ in Myocardial Ischemia-induced Heart Failure in Sprague-dawley Rats and Beagles

INTRODUCTION

Nicotinamide adenine dinucleotide (NAD+) participates in various processes that are dysregulated in cardiovascular diseases. Supplementation with NAD+ may be cardioprotective. However, whether the protective effect exerted by NAD+ in heart failure (HF) is more effective before acute myocardial infarction (MI) or after remains unclear. The left anterior descending arteries of male Sprague Dawley rats and beagles that developed HF following MI were ligated for 1 week, following which the animals were treated for 4 weeks with low, medium, and high doses of NAD+ and LCZ696.

METHODS

Cardiac function, hemodynamics, and biomarkers were evaluated during the treatment period. Heart weight, myocardial fibrosis, and MI rate were measured eventually.

RESULTS

Compared with the HF groups, groups treated with LCZ696 and different doses of NAD+ showed increased ejection fractions, fractional shortening, cardiac output, and stroke volume and decreased end-systolic volume, end-systolic dimension, creatine kinase, and lactic dehydrogenase. LV blood pressure was lower in the HF group than in the control group, but this decrease was significantly greater in the medium and high NAD+ dose groups.

CONCLUSION

The ratios of heart weight indexes, fibrotic areas, and MI rates in the CZ696 and medium and high NAD+ dose groups were lower than those in the HF group. Medium and highdose NAD+ showed superior positive effects on myocardial hypertrophy, cardiac function, and myocardial fibrosis and reduced the MI rate.

Pharmaceutical Cocrystal Discovery via 3D-SMINBR: A New Network Recommendation Tool Augmented by 3D Molecular Conformations

Cocrystals have significant potential in various fields such as chemistry, material, and medicine. For instance, pharmaceutical cocrystals have the ability to address issues associated with physicochemical and biopharmaceutical properties. However, it can be challenging to find proper coformers to form cocrystals with drugs of interest. Herein, a new in silico tool called 3D substructure-molecular-interaction network-based recommendation (3D-SMINBR) has been developed to address this problem. This tool first integrated 3D molecular conformations with a weighted network-based recommendation model to prioritize potential coformers for target drugs. In cross-validation, the performance of 3D-SMINBR surpassed the 2D substructure-based predictive model SMINBR in our previous study. Additionally, the generalization capability of 3D-SMINBR was confirmed by testing on unseen cocrystal data. The practicality of this tool was further demonstrated by case studies on cocrystal screening of armillarisin A (Arm) and isoimperatorin (iIM). The obtained Arm-piperazine and iIM-salicylamide cocrystals present improved solubility and dissolution rate compared to their parent drugs. Overall, 3D-SMINBR augmented by 3D molecular conformations would be a useful network-based tool for cocrystal discovery. A free web server for 3D-SMINBR can be freely accessed at http://lmmd.ecust.edu.cn/netcorecsys/.

LCZ696 (sacubitril/valsartan) inhibits pulmonary hypertension induced right ventricular remodeling by targeting pyruvate dehydrogenase kinase 4

BACKGROUND

Right ventricular (RV) function is a major prognostic factor in patients with cardiopulmonary disease. Effective medical therapies are available for left heart failure, but they are usually less effective or even ineffective in right heart failure. Here, we tested the hypothesis that LCZ696 (sacubitril/valsartan) can attenuate pressure overload-induced RV remodeling by inhibiting pyruvate dehydrogenase kinase 4 (PDK4).

METHODS

Adult male C57 mice were subjected to transverse aortic constriction (TAC), pulmonary artery constriction (PAC), or sham surgery. Bioinformatics analysis was used to screen for common differentially expressed genes (DEGs) between TAC and PAC. Chemical compounds targeting DEGs were predicted by molecular docking analysis. Effects of LCZ696 on PAC-induced RV remodeling and the associated PDK4-related mechanisms were investigated.

RESULTS

We found 60 common DEGs between PAC and TAC, and Pdk4 was one of the downregulated DEGs. From 47 chemical compounds with potential cardiovascular activity and PDK4 protein binding ability, we selected LCZ696 to treat PAC-induced RV remodeling because of its high docking score for binding PDK4. Compared with vehicle-treated PAC mice, LCZ696-treated mice had significantly smaller RV wall thickness and RV diameters, less myocardial fibrosis, lower expression of PDK4 protein, and less phosphorylation of glycogen synthase kinase-3β (p-GSK3β). In PAC mice, overexpression of Pdk4 blocked the inhibitory effect of LCZ696 on RV remodeling, whereas conditional knockout of Pdk4 attenuated PAC-induced RV remodeling.

CONCLUSIONS

Pdk4 is a common therapeutic target for pressure overload-induced left ventricular and RV remodeling, and LCZ696 attenuates RV remodeling by downregulating Pdk4 and inhibiting PDK4/p-GSK3β signal.

The initial timing and dosage pattern of sacubitril/valsartan in patients with acute myocardial infarction undergoing percutaneous coronary intervention

BACKGROUND

In real-world clinical practice, the initiation and up-titration of sacubitril/valsartan remain challenging due to symptomatic hypotension in patients with acute myocardial infarction(AMI). The purpose of this study was to investigate the efficacy of different initial timing and dosage of sacubitril/valsartan in AMI patients.

METHODS

This prospective and observational cohort study enrolled AMI patients treated with percutaneous coronary intervention(PCI), and were categorized according to the initial timing and average daily doses of sacubitril/valsartan prescription. The primary endpoint was defined as a composite of cardiovascular death, recurrent AMI, coronary revascularization, heart failure(HF) hospitalization and ischaemic stroke. Secondary outcomes included the new-onset HF, and the composite endpoints in AMI patients complicated with HF at baseline.

RESULTS

The study population consisted of 915 AMI patients. After a median follow-up of 38 months, early use or high dosage of sacubitril/valsartan was associated with an improvement in primary endpoint as well as the incidence of new-onset HF. Early use of sacubitril/valsartan also ameliorated the primary endpoint in AMI patients with left ventricular ejection fraction(LVEF) ≤50% as well as LVEF>50%. Besides, early use of sacubitril/valsartan improved the clinical outcomes in AMI patients complicated with HF at baseline. The low dose was well tolerated and may be associated with similar outcomes compared with high dose under some circumstances(LVEF>50% or HF at baseline).

CONCLUSIONS

Early use or high dosage of sacubitril/valsartan medication is associated with an improvement in clinical outcome. The low dose of sacubitril/valsartan is well tolerated and may be an acceptable alternative strategy.

Sinus node dysfunction and atrial fibrillation-Relationships, clinical phenotypes, new mechanisms, and treatment approaches

Although the anatomical basis of the pathogenesis of sinus node dysfunction (SND) and atrial fibrillation (AF) is located primarily in the left and right atria, increasing evidence suggests a strong correlation between SND and AF, in terms of both clinical presentation and formation mechanisms. However, the exact mechanisms underlying this association are unclear. The relationship between SND and AF may not be causal, but is likely to involve common factors and mechanisms, including ion channel remodeling, gap junction abnormalities, structural remodeling, genetic mutations, neuromodulation abnormalities, the effects of adenosine on cardiomyocytes, oxidative stress, and viral infections. Ion channel remodeling manifests primarily as alterations in the "funny" current (I_f) and Ca²⁺ clock associated with cardiomyocyte autoregulation, and gap junction abnormalities are manifested primarily as decreased expression of connexins (Cxs) mediating electrical impulse propagation in cardiomyocytes. Structural remodeling refers primarily to fibrosis and cardiac amyloidosis (CA). Some genetic mutations can also cause arrhythmias, such as SCN5A, HCN4, EMD, and PITX2. The intrinsic cardiac autonomic nervous system (ICANS), a regulator of the heart's physiological functions, triggers arrhythmias.In addition, we discuss arrhythmias caused by viral infections, notably Coronavirus Disease 2019 (COVID-19). Similarly to upstream treatments for atrial cardiomyopathy such as alleviating CA, ganglionated plexus (GP) ablation acts on the common mechanisms between SND and AF, thus achieving a dual therapeutic effect.

Effects of sacubitril/valsartan on cardiac reverse remodeling and cardiac resynchronization in patients with acute myocardial infarction

Introduction

In 2014, the PARADIGM-HF trial (Prospective Comparison of ARNI with ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure) has shown that sacubitril/valsartan can reduce the risk of hospitalization and death from cardiovascular causes more effectively than enalapril (an ACEI) in heart failure patients with reduced ejection fraction (HFrEF). Similarly, the PARADIGM-HF trial (Comparison of Sacubitril-Valsartan vs. Enalapril on Effect on NT-proBNP in Patients Stabilized from an Acute Heart Failure Episode) came to similar conclusions and extended the PARADIGM-HF trial results in 2019. Since then, numerous new studies have provided further insight in HFrEF, sacubitril/valsartan can reduce N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, increase left ventricular ejection fraction (LVEF), reverse ventricular remodeling, and reduce other non-fatal manifestations of clinical deterioration as compared to ACEI/ARB. However, few trials have compared the effects of these drugs in patients shortly after AMI. Therefore, it is necessary to further explore the clinical efficacy and safety of sacubitril/valsartan vs. valsartan in patients with AMI.

Methods

We conducted an open-label, prospective, randomized controlled trial to determine the superiority in ameliorating ventricular remodeling and preventing of heart failure in patients with AMI after percutaneous coronary intervention (PCI), 148 patients were randomly assigned (85 to sacubitril/valsartan and 63 to valsartan).

Results

LAV, LVDV, and LVSV were all decreased in the sacubitril/valsartan group when compared with before treatment, but there was no difference between the sacubitril/valsartan group and the valsartan group. In addition, compared with before treatment in the sacubitril/valsartan group, the heart global work index (GWI) and the global work efficiency (GWE) increased, while the heart global wasted work (GWW) decreased. Patients in the sacubitril/valsartan group have similar MACE and adverse side effects to those in the valsartan group.

Conclusion

Sacubitril/valsartan has the same performance as valsartan in inhibiting ventricular remodeling and preventing heart failure after PCI in patients with AMI, and its clinical application is safe. It provides a clinical foundation for the application of sacubitril/valsartan in patients with AMI.

Neprilysin Inhibition in the Prevention of Anthracycline-Induced Cardiotoxicity

Anthracycline-induced cardiotoxicity (AIC) poses a clinical challenge in the management of cancer patients. AIC is characterized by myocardial systolic dysfunction and remodeling, caused by cardiomyocyte DNA damage, oxidative stress, mitochondrial dysfunction, or renin-angiotensin-aldosterone system (RAAS) dysregulation. In the past decade, after positive results of a PARADIGM-HF trial, a new class of drugs, namely angiotensin receptor/neprilysin inhibitors (ARNi), was incorporated into the management of patients with heart failure with reduced ejection fraction. As demonstrated in a variety of preclinical studies of cardiovascular diseases, the cardioprotective effects of ARNi administration are associated with decreased oxidative stress levels, the inhibition of myocardial inflammatory response, protection against mitochondrial damage and endothelial dysfunction, and improvement in the RAAS imbalance. However, data on ARNi's effectiveness in the prevention of AIC remains limited. Several reports of ARNi administration in animal models of AIC have shown promising results, as ARNi prevented ventricular systolic dysfunction and electrocardiographic changes and ameliorated oxidative stress, mitochondrial dysfunction, endoplasmic reticulum stress, and the inflammatory response associated with anthracyclines. There is currently an ongoing PRADAII trial aimed to assess the efficacy of ARNi in patients receiving breast cancer treatment, which is expected to be completed by late 2025.

Short-term efficacy of angiotensin receptor-neprilysin inhibitor treatment in patients with ST-segment elevation myocardial infarction with reduced ejection fraction after primary percutaneous coronary intervention: a propensity score matching study

Background

Acute myocardial infarction (AMI) causes a series of pathophysiological changes, including myocardial necrosis, myocardial edema, and microvascular damage. These changes eventually lead to severe cardiovascular events, such as ventricular remodeling, heart failure, and papillary dysfunction. Impaired cardiac function after ST-segment elevation myocardial infarction (STEMI) often manifests as a decrease in left ventricular ejection fraction (LVEF). Clinical trials have shown that angiotensin receptor-neprilysin inhibitor (ARNI) treatment has the potential to improve LVEF in patients with STEMI after primary percutaneous coronary intervention (PPCI).

Objective

The purpose of this study was to evaluate the short-term efficacy of ARNI versus angiotensin-converting enzyme inhibitor (ACEI) treatment in patients with STEMI who exhibit reduced LVEF after PPCI.

Methods

A total of 169 patients with STEMI exhibiting post-PPCI LVEF below 50% who were orally treated with ARNI between December 2017 and August 2020 were selected as the experimental group. A total of 136 patients with STEMI exhibiting post-PPCI LVEF below 50% who were orally treated with an ACEI between January 2016 and August 2020 were selected as the control group. LVEF was measured using cardiac ultrasonography during hospitalization and 3 months after discharge. Linear and logistic regression analyses were performed to compare patient demographics and hospitalization variables to evaluate the risk factors for change and rate of improvement in LVEF. Propensity score matching (PSM) was used to account for confounding factors.

Results

After PSM, the study cohort consisted of 81 patients in the ARNI group and 123 in the ACEI group. After an average follow-up period of 3 months, no significant difference was noted in the LVEF improvement rate between the experimental and control groups (P = 0.475, 95% CI: -0.062 to 0.134). Multivariate logistic regression analysis also indicated no significant correlation between the change in LVEF and oral ARNI treatment in patients with STEMI exhibiting reduced LVEF after PPCI (P > 0.05).

Conclusion

The short-term effect of ARNI treatment on the cardiac function of patients with STEMI and reduced LVEF after PPCI is not superior to that of ACEI treatment.

Transcriptomic profile analysis of the left atrium in spontaneously hypertensive rats in the early stage

Left atrial remodeling, characterized by enlargement and hypertrophy of the left atrium and increased fibrosis, was accompanied by an increased incidence of atrial fibrillation. While before morphological changes at the early stage of hypertension, how overloaded hypertension influences the transcriptomic profile of the left atrium remains unclear. Therefore, RNA-sequencing was performed to define the RNA expressing profiles of left atrium in spontaneously hypertensive rats (SHRs) and normotensive Wistar-Kyoto (WKY) rats as a control group. We also compared the changes in the RNA expression profiles in SHRs treated with an angiotensin receptor blocker (ARB) and angiotensin receptor-neprilysin inhibitor (ARNI) to assess the distinct effects on the left atrium. In total, 1,558 differentially expressed genes were found in the left atrium between WKY rats and SHRs. Bioinformatics analysis showed that these mRNAs could regulate upstream pathways in atrial remodeling through atrial fibrosis, inflammation, electrical remodeling, and cardiac metabolism. The regulated transcripts detected in the left atrial tissue in both the ARB-treated and ARNI-treated groups were related to metabolism. In contrast to the ARB-treated rates, the transcripts in ARNI-treated rats were mapped to the cyclic guanosine monophosphate-protein kinase G signaling pathway.

A systematic review and meta-analysis of sacubitril-valsartan in the treatment of ventricular remodeling in patients with heart failure after acute myocardial infarction

Objective

To systematically review the efficacy and safety of sacubitril and valsartan in treating acute myocardial infarction complicated with heart failure and to observe whether it can further improve patients' cardiac function, delay left ventricular remodeling, and reduce major adverse cardiovascular events (MACEs).

Methods

Electronic databases including Pubmed, Embase, the Web of Science, Cochrane Library, Scopus, CNKI, Wanfang Data, and VIP were searched. The search period was from the establishment of the database to March 2022 to search for relevant controlled trials. Two investigators independently screened the literature, extracted data, and assessed the risk of bias. Revman5.3 and Stata14 software were used for statistical analysis.

Results

A total of 13 studies, with 6,968 patients were included. Meta-analysis results showed that sacubitril-valsartan increased left ventricular ejection fraction (LVEF) and decreased NT-proBNP level was better at 6 months and within 3 months of follow-up compared with the control group (P < 0.00001), but there was no significant difference at the 12-month follow-up (P > 0.05). Sacubitril-valsartan reducing LVEDD [MD = -2.55, 95%CI(-3.21, -1.88), P < 0.00001], LVEDVI [MD = -3.61, 95%CI(-6.82, -0.39), P = 0.03], LVESVI [MD = -3.77, 95%CI(-6.05, -1.49), P = 0.001], and increasing the distance of the 6-min walk test [MD = 48.20, 95%CI(40.31, 56.09), P < 0.00001] were more effective. Compared with ACEI/ARB, the use of ARNI can further reduce the total incidence of adverse cardiovascular events [RR = 0.72, 95%CI(0.62, 0.84), P<0.0001] and the rate of HF rehospitalization [RR = 0.73, 95%CI(0.61, 0.86), P = 0.0002] in patients with acute myocardial infarction and heart failure; there was no significant difference in the incidence of cardiac death, recurrence of myocardial infarction, and malignant arrhythmia between the experimental group and the control group (P > 0.05). In terms of the incidence of adverse reactions, the incidence of cough in ARNI was lower than that in ACEI/ARB group [RR = 0.69, 95%CI(0.60, 0.80), P < 0.00001], but the incidence of hypotension was higher [RR = 1.29, 95%CI(1.18, 1.41), P < 0.00001], and the adverse reactions of hyperkalemia, angioedema and renal insufficiency were not increased (P > 0.05).

Conclusion

The use of sacubitril-valsartan sodium in patients with acute myocardial infarction complicated with heart failure can significantly improve cardiac function and reverse ventricular remodeling, reducing the risk of re-hospitalization for heart failure. There is no apparent adverse reaction except easy cause hypotension.

Systematic trial registration

[www.ClinicalTrials.gov], identifier [CRD42022322901].

Sacubitril/valsartan attenuates myocardial ischemia/reperfusion injury via inhibition of the GSK3β/NF-κB pathway in cardiomyocytes

In ischemia/reperfusion (I/R) injury, both inflammation and apoptosis play a vital role, and the inhibition of excessive inflammation and apoptosis show substantial clinical potential in the treatment of I/R disease. The role of sacubitril/valsartan (SAC/VAL)-a first-in-class angiotensin receptor-neprilysin inhibitor (ARNI)-in inflammation regulation and apoptosis in the context of I/R injury needs to be further explored. In this study, we investigate the short- and long-term effects of SAC/VAL administration in treating adult murine I/R injury both in vivo and in vitro. Our results verified that the application of SAC/VAL could reduce infarct size and suppress apoptosis and the inflammatory response in the acute phase post I/R. Long-term application of SAC/VAL for four weeks significantly improved ventricular function and reversed pathological ventricular remodeling. Mechanistically, SAC/VAL treatment induces the inhibition of the GSK3β-mediated NF-κB pathway through synergistically blocking angiotensin 1 receptor (AT1R) and activating natriuretic peptide receptor (NPR). In summary, we reported the therapeutic role of SAC/VAL in regulating the GSK3β/NF-κB signaling pathway to suppress the inflammatory response and apoptosis, thereby reducing cardiac dysfunction and remodeling post I/R.

Sacubitril Valsartan Enhances Cardiac Function and Alleviates Myocardial Infarction in Rats through a SUV39H1/SPP1 Axis

Sacubitril valsartan (lcz696) has been demonstrated as a substitute for angiotensin-converting enzyme inhibitors and angiotensin receptor blockers for the treatment of heart failure. This research is aimed at examining the effects of lcz696 and its target molecules on myocardial infarction (MI). A rat model of MI was induced by left anterior descending artery ligation and treated with lcz696. Lcz696 treatment significantly reduced cardiac injury and heart failure, restored the left ventricular fractional shortening and ejection fraction, and reduced oxidative stress and inflammatory responses in rat myocardium. By analyzing the heart failure-related GSE47495 dataset and performing gene ontology (GO) functional enrichment analysis, we obtained histone lysine methyltransferase SUV39H1 and secreted phosphoprotein 1 (SPP1) as two molecules implicated in the oxidative stress and inflammation processes. An elevation of SUV39H1 whereas a decline of SPP1 were detected in cardiac tissues after lcz696 treatment. Enrichments of SUV39H1 and H3K9me3 at the SPP1 promoter were identified by chromatin immunoprecipitation assay. SUV39H1 catalyzed H3K9me3 modification to suppress the expression of SPP1. Preconditioning of SUV39H1 silencing blocked the protective roles of lcz696, but SPP1 silencing alleviated the myocardial injury. In conclusion, this study demonstrates that lcz696 enhances cardiac function and alleviates MI in rats through a SUV39H1/SPP1 axis.

The impact of Sacubitril/Valsartan on cardiac fibrosis early after myocardial infarction in hypertensive rats

BACKGROUND

Sacubitril/Valsartan, a dual inhibitor of the neprilysin and angiotensin receptor, exerts cardioprotective effects in heart failure. Little is known on the impact of Sacubitril/Valsartan in hypertensive patients early post myocardial infarction.

METHODS

Spontaneously hypertensive rats (SHR) were pretreated by daily angiotensin receptor blocker (ARB; 30 mg/kg intraperitoneally), Sacubitril/Valsartan (ARNI; 60 mg/kg intraperitoneally) or the same dosage of physiological saline for 1 week. Then each group underwent myocardial infarction induction and received the same treatment for another week. The blood pressure and cardiac function were evaluated prior to sacrifice. We performed histological and molecular evaluation of fibrosis in vivo and in vitro.

RESULTS

The blood pressure was comparable between three groups both 1 week prior to and post myocardial infarction. ARNI and ARB restore the decreased ejection fraction (57.3 ± 7.6 vs. 42.9 ± 5.2%, P < 0.05; 54.3 ± 6.9 vs. 42.9 ± 5.2%, P < 0.01, respectively) and fractional shortening (31.6 ± 5.4 vs. 22.1 ± 3.1%, P < 0.05; 29.4 ± 4.5 vs. 22.1 ± 3.1%, P < 0.05, respectively) post myocardial infarction. The infarct size and collagen deposition were also significantly mitigated in ARNI and ARB groups. In addition, ARNI and ARB treatment reduced the expression of cardiac remodeling-related factors, such as Bnp, α-SMA, Vimentin, and Col1a1 (all P < 0.05 vs. MI group). Finally, ARNI and ARB decreased the expression of α-SMA in cardiac fibroblasts treated with Ang II.

CONCLUSION

In conclusion, pretreatment with ARNI maintained cardiac function and reduced myocardial fibrosis in myocardial infarction, probably prior to any anti-hypertensive effect.

Efficacy and safety of sacubitril/valsartan vs. valsartan in patients with acute myocardial infarction: A meta-analysis

Background

The angiotensin-receptor neprilysin inhibitor (ARNI) sacubitril/valsartan was shown to be superior to the angiotensin receptor blocker (ARB) valsartan in terms of reversing heart failure classification (NYHA classification), reducing N-terminal pro-brain natriuretic peptide (NT-proBNP) level and cardiovascular mortality in many studies. Yet, the efficacy of ARNI did not come from patients with acute myocardial infarction (AMI).

Methods

We searched databases for research published from inception to July 29, 2022, that reported cardiac reverse remodeling (CRR) or security indices. Two reviewers independently screened literature, extracted data, and assessed the risk of bias. Nine studies enrolling 1,369 patients were included to perform a meta-analysis. There were 716 patients in the ARNI group and 653 in the ARB group.

Results

ARNI outperformed ARBs in terms of CRR indices, with striking changes in left ventricular ejection fraction (EF) (MD: 4.12%, 95%CI: 2.36, 5.88, P &lt; 0.0001), diameter (MD: –3.40 mm, 95%CI: –4.30, –2.94, P &lt; 0.00001, I2 = 0%) and left atrial diameter (MD: –2.41 mm, 95%CI: –3.85, –0.97, P = 0.001, I2 = 0%), other indices there showed no significant improvements. The incidences of major adverse cardiac events (RR: 0.47, 95%CI: 0.34–0.65, P &lt; 0.00001, I2 = 0%), the heart failure (RR: 0.37, 95%CI: 0.23–0.61, P &lt; 0.0001, I2 = 0%), readmission (RR: 0.54, 95%CI: 0.36–0.80, P = 0.003, I2 = 29%) in the sacubitril/valsartan group were lower than the ARB group, while the incidences of cardiac death (RR: 0.56, 95%CI: 0.28, 1.09, P = 0.09), the myocardial infarction (RR: 0.83, 95% CI: 0.39, 1.77, P = 0.63), adverse side effects (RR: 1.67, 95% CI: 0.89, 3.13, P = 0.11) showed no difference.

Conclusion

This research indicated that early initiation of sacubitril/valsartan in patients after AMI was superior to ARBs in reducing the risks of major adverse cardiac events, heart failure, readmission, and enhancing left ventricular EF, decreasing diameter, left atrial diameter. As for the other outcomes (the incidences of cardiac death, myocardial infarction, and adverse side effects), sacubitril/valsartan demonstrated no obvious advantage over ARBs.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier [CRD42022307237].

Effects of Sacubitril/Valsartan on the Expression of CaMKII/Cav1.2 in Atrial Fibrillation Stimulation Rabbit Model

Background and Objective. Atrial fibrillation (AF) is linked to high morbidity and death rates throughout the world due to limited therapeutic options and thus presents a major challenge to the developed and developing countries. In this study, we aim to investigate the influence of sacubitril/valsartan (sac/val) treatment on the calmodulin-dependent protein kinase II (CaMKII)/Cav1.2 expression in AF models. Methods. Overall, 18 rabbits were randomly divided into control, pacing (600 beats/min), and pacing+sac/val groups. The rabbits in the pacing+sac/val cohort received oral sac/val (10 mg/kg twice daily) across the 21-day investigation period. After three weeks, the atrial effective refractory period (AERP) and AF induction rate were compared. HL-1 cultures were exposed to fast pacing (24 h) with and without LBQ657 (active sacubitril form)/valsartan. Western blots were used for detecting Cav1.2 and CaMKII expression within atrial muscles of the rabbits and HL-1 cultures of AF model. Results. In comparison to the sham cohort, the AF induction rate was markedly increased together with AERP reduction within pacing cohort. Such changes were markedly rescued through sac/val treatment in pacing+sac/val cohort. The proteomic expression profiles of CaMKII and Cav1.2 showed that the CaMKII expression was markedly upregulated, while Cav1.2 expression was downregulated in the pacing cohort. Importantly, these effects were absent in pacing+sac/val cohort. Conclusion. Results of this study show that sac/val treatment regulates the expression of CaMKII/Cav1.2 and could alter this pathway in atrial rapid electrical stimulation models. Therefore, this investigation could contribute to a novel strategy in AF therapeutics in clinical settings.

Roles of Natriuretic Peptides and the Significance of Neprilysin in Cardiovascular Diseases

Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) activate the guanylyl cyclase A receptor (GC-A), which synthesizes the second messenger cGMP in a wide variety of tissues and cells. C-type natriuretic peptide (CNP) activates the cGMP-producing guanylyl cyclase B receptor (GC-B) in chondrocytes, endothelial cells, and possibly smooth muscle cells, cardiomyocytes, and cardiac fibroblasts. The development of genetically modified mice has helped elucidate the physiological roles of natriuretic peptides via GC-A or GC-B. These include the hormonal effects of ANP/BNP in the vasculature, autocrine effects of ANP/BNP in cardiomyocytes, and paracrine effects of CNP in the vasculature and cardiomyocytes. Neprilysin (NEP) is a transmembrane neutral endopeptidase that degrades the three natriuretic peptides. Recently, mice overexpressing NEP, specifically in cardiomyocytes, revealed that local cardiac NEP plays a vital role in regulating natriuretic peptides in the heart tissue. Since NEP inhibition is a clinically accepted approach for heart failure treatment, the physiological roles of natriuretic peptides have regained attention. This article focuses on the physiological roles of natriuretic peptides elucidated in mice with GC-A or GC-B deletion, the significance of NEP in natriuretic peptide metabolism, and the long-term effects of angiotensin receptor-neprilysin inhibitor (ARNI) on cardiovascular diseases.

Sacubitril/valsartan in Heart Failure and Beyond-From Molecular Mechanisms to Clinical Relevance

As the ultimate pathophysiological event, heart failure (HF) may arise from various cardiovascular (CV) conditions, including sustained pressure/volume overload of the left ventricle, myocardial infarction or ischemia, and cardiomyopathies. Sacubitril/valsartan (S/V; formerly termed as LCZ696), a first-in-class angiotensin receptor/neprilysin inhibitor, brought a significant shift in the management of HF with reduced ejection fraction by modulating both renin-angiotensin-aldosterone system (angiotensin II type I receptor blockage by valsartan) and natriuretic peptide system (neprilysin inhibition by sacubitril) pathways. Besides, the efficacy of S/V has been also investigated in the setting of other CV pathologies which are during their pathophysiological course and progression deeply interrelated with HF. However, its mechanism of action is not entirely clarified, suggesting other off-target benefits contributing to its cardioprotection. In this review article our goal was to highlight up-to-date clinical and experimental evidence on S/V cardioprotective effects, as well as most discussed molecular mechanisms achieved by this dual-acting compound. Although S/V was extensively investigated in HF patients, additional large studies are needed to elucidate its effects in the setting of other CV conditions. Furthermore, with its antiinflamatory potential, this agent should be investigated in animal models of inflammatory heart diseases, such as myocarditis, while it may possibly improve cardiac dysfunction as well as inflammatory response in this pathophysiological setting. Also, discovering other signalling pathways affected by S/V should be of particular interest for basic researches, while it can provide additional understanding of its cardioprotective mechanisms.

The Efficacy and Safety of the Combined Therapy of Sodium-Glucose Co-Transporter-2 Inhibitors and Angiotensin Receptor-Neprilysin Inhibitor in Patients With Heart Failure With Reduced Ejection Fraction: A Meta-Analysis of the EMPEROR-Reduced and DAPA-HF Sub-Analysis

Background

Both sodium-glucose co-transporter-2 (SGLT-2) inhibitors and angiotensin receptor-neprilysin inhibitor (ARNI) were recommended to treat heart failure with reduced ejection fraction (HFrEF). However, no trial was conducted to assess the efficacy and safety of the combined therapy of SGLT-2 inhibitors and ARNI in patients with HFrEF.

Methods

We performed a meta-analysis of the prespecified subgroups from DAPA-HF and EMPEROR-Reduced trials. The primary endpoint was the composite risk of cardiovascular death or hospitalization for heart failure. The risk of cardiovascular death, all-cause death, a composite of serious adverse renal outcomes, and volume depletion were also estimated.

Results

The risk of the composite of cardiovascular death or hospitalization for heart failure was reduced in combined therapy of SGLT-2 inhibitors and ARNI, compared with ARNI monotherapy (RR.68, 95% CI.53 to.85, P = 0.001). When compared with SGLT-2 inhibitors monotherapy, the events of cardiovascular death (RR.64, 95% CI.46 to 0.87, P = 0.005) and all-cause death (RR.72, 95% CI.55 to.94, P = 0.01) were significantly less in combined therapy, accompanied by elevated incidence of volume depletion (RR 1.55, 95% CI 1.22 to 1.96, P = 0.0003).

Conclusion

Combined therapy has additional benefits over monotherapy in patients with HFrEF, however, it is accompanied by a possibly higher risk of volume depletion.

LCZ696 Ameliorates Isoproterenol-Induced Acute Heart Failure in Rats by Activating the Nrf2 Signaling Pathway

Objective

LCZ696 (sacubitril/valsartan) is an angiotensin II (Ang II) type 1 receptor-neprilysin inhibitor, with effects of immunosuppression, anti-inflammation, antiapoptosis, and antioxidation. The present study was aimed at determining whether LCZ696 has a protective effect against isoproterenol-induced acute heart failure (AHF) in rats.

Methods

SD rats were randomly divided into four groups: control group, HF group, LCZ696 group, and enalapril group. The cardiac function of rats was evaluated using echocardiographic parameters, heart weight (HW), serum levels of cardiac troponin I (cTnI), and lactate dehydrogenase (LDH). HE is staining, which was used to determine the pathological damage of rat myocardial tissue. Also, we measured oxidative stress markers including reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT). Finally, the expression of Nrf2 signaling pathway-related proteins was determined using Western blot.

Results

Compared with the HF group, LCZ696 could significantly improve cardiac function and myocardial injury in rats and reduce AHF-induced oxidative stress. In addition, the results of Western blot confirmed that LCZ696 could upregulate the expression of Nrf2 and HO-1 while decreasing Keap1 expression.

Conclusion

LCZ696 ameliorates isoproterenol-induced AHF in rats by alleviating oxidative stress injury and activating the Nrf2 signaling pathway.

Comparing the efficacy of angiotensin receptor-neprilysin inhibitor and enalapril in acute anterior STEMI patients after primary percutaneous coronary intervention: a prospective randomized trial

BACKGROUND

For patients with heart failure (HF), the effect of angiotensin receptor-neprilysin inhibitors (ARNIs, sacubitril/valsartan) on cardiac remodeling has been found to be superior to angiotensin-converting enzyme inhibitors (ACEI). However, little data have described the impact of early-initiation ARNI in patients with acute anterior ST-segment elevation myocardial infarction (STEMI).

METHODS

In this prospective, randomized, double-blind, parallel-group trial, we enrolled 131 anterior STEMI patients who were treated with primary percutaneous coronary intervention (PCI) between February 2019 and December 2019. All patients received standard STEMI management and were divided into 2 groups (ARNI/enalapril). Primary efficacy outcomes were the between-group difference in change (from baseline to 4-, 12-, and 24-week) in N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentration, left ventricular ejection fraction (LVEF), and left ventricular end-systolic volumes and end-diastolic volumes (LVESV and LVEDV). Secondary outcomes were determined by a composite of death, reinfarction, outpatient HF or HF hospitalization, malignant arrhythmia, and stroke. Safety outcomes included worsening renal function, hypotension, hyperkalemia, angioedema and cough.

RESULTS

We found that NT-proBNP concentration decreased more in the ARNI group than in the enalapril group [4 weeks: ratio of ARNI vs. enalapril 0.36, 95% confidence interval (CI): 0.24 to 0.52, P<0.001; 12 weeks: 0.54, 95% CI: 0.35 to 0.79, P<0.001; 24 weeks: 0.53, 95% CI: 0.32 to 0.83, P<0.001). When compared to the enalapril group, the ARNI group patients had a significant reduction in LVEDV (P<0.001) and LVESV (P<0.001), and an improvement in LVEF (P=0.011) at 24 weeks. Secondary outcomes occurred in 13 participants (20.3%) in the ARNI group and 22 participants (34.4%) in the enalapril group [hazard ratio (HR), 0.56; 95% CI: 0.28 to 1.12; P=0.102]. The incidence of outpatient HF or HF hospitalization in the ARNI group was significantly lower than that in the enalapril group (HR, 0.36; 95% CI: 0.14 to 0.94; P=0.037). There were no significant differences in the safety between the 2 groups.

CONCLUSIONS

For patients with acute anterior STEMI undergoing primary PCI, early initiation of ARNI provided significant clinical benefits.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR2100042944) registered on February 1, 2021.

Sacubitril Ameliorates Cardiac Fibrosis Through Inhibiting TRPM7 Channel

Heart failure caused by cardiac fibrosis has become a major challenge of public health worldwide. Cardiomyocyte programmed cell death (PCD) and activation of fibroblasts are crucial pathological features, both of which are associated with aberrant Ca²⁺ influx. Transient receptor potential cation channel subfamily M member 7 (TRPM7), the major Ca²⁺ permeable channel, plays a regulatory role in cardiac fibrosis. In this study, we sought to explore the mechanistic details for sacubitril, a component of sacubitril/valsartan, in treating cardiac fibrosis. We demonstrated that sacubitril/valsartan could effectively ameliorate cardiac dysfunction and reduce cardiac fibrosis induced by isoprotereno (ISO) in vivo. We further investigated the anti-fibrotic effect of sacubitril in fibroblasts. LBQ657, the metabolite of sacubitril, could significantly attenuate transforming growth factor-β 1 (TGF-β1) induced cardiac fibrosis by blocking TRPM7 channel, rather than suppressing its protein expression. In addition, LBQ657 reduced hypoxia-induced cardiomyocyte PCD via suppression of Ca²⁺ influx regulated by TRPM7. These findings suggested that sacubitril ameliorated cardiac fibrosis by acting on both fibroblasts and cardiomyocytes through inhibiting TRPM7 channel.

Does sacubitril/valsartan work in acute myocardial infarction? The PARADISE-AMI study

Patients with acute myocardial infarction (AMI) complicated by left ventricular dysfunction have an increased risk of death and heart failure. Numerous clinical studies have demonstrated the ability of ACE inhibitors in optimizing the outcome in this particular clinical setting. In recent years, the sacubitril/valsartan association has drastically improved the prognosis of patients with heart failure with reduced ejection fraction with a significant decrease in mortality from cardiovascular causes and hospitalizations due to acute heart failure. However, it has not yet been fully clarified whether this pharmacological association may play a role in patients with AMI. Pre-clinical studies have suggested the possibility that sacubitril/valsartan can reduce the size of the infarct scar and prevent the onset of ventricular arrhythmias in laboratory animals in which myocardial infarction was induced. On the other hand, small clinical experiences with patients after myocardial infarction have provided conflicting data. The results of the PARADISE-MI study were recently presented, which enrolled 5661 patients with AMI complicated by pulmonary congestion and left ventricular dysfunction randomized to therapy with ramipril or sacubitril/valsartan and followed up for ∼2 years. Although combination therapy was associated with an ∼10% reduction in the risk of death from cardiovascular causes or an episode of heart failure, this was not enough to achieve statistical significance. However, treatment with sacubitril/valsartan was shown to be more effective than ramipril in preventing recurrence of heart failure after the first one.

Sacubitril/Valsartan Alleviates Experimental Autoimmune Myocarditis by Inhibiting Th17 Cell Differentiation Independently of the NLRP3 Inflammasome Pathway

Sacubitril/valsartan (Sac/Val) is a recently approved drug that is commonly used for treatment of heart failure. Several studies indicated that Sac/Val also regulated the secretion of inflammatory factors. However, the effect and mechanism of this drug modulation of inflammatory immune responses are uncertain. In this study, an experimental autoimmune myocarditis (EAM) mouse model was established by injection of α-myosin-heavy chain peptides. The effect of oral Sac/Val on EAM was evaluated by histological staining of heart tissues, measurements of cardiac troponin T and inflammatory markers (IL-6 and hsCRP). The effects of Sac/Val on NLRP3 inflammasome activation and Th1/Th17 cell differentiation were also determined. To further explore the signaling pathways, the expressions of cardiac soluble guanylyl cyclase (sGC) and NF-κB p65 were investigated. The results showed that Sac/Val downregulated the inflammatory response and attenuated the severity of EAM, but did not influence NLRP3 inflammasomes activation. Moreover, Sac/Val treatment inhibited cardiac Th17 cell differentiation, and this might be associated with sGC/NF-κB p65 signaling pathway. These findings indicate the potential use of Sac/Val for treatment of myocarditis.

Sacubitril/valsartan (LCZ696) reduces myocardial injury following myocardial infarction by inhibiting NLRP3‑induced pyroptosis via the TAK1/JNK signaling pathway

The present study aimed to investigate the protective effects of sacubitril/valsartan (LCZ696) on ventricular remodeling in myocardial infarction (MI) and the effects of the inflammasome‑mediated inflammatory response. First, a rat model was established. Animals were then treated with LCZ696 so that the histopathological changes associated with ventricular remodeling could be investigated. The serum levels of the inflammatory factors IL‑18 and IL‑1β were also determined by ELISA. Immunofluorescence was used to investigate the ratio of pyroptosis following MI modelling. Western blotting and reverse transcription‑quantitative PCR were used to detect the relative expression levels of proteins and mRNAs in the transforming growth factor β‑activated kinase‑1 (TAK1)/JNK pathway and those associated with the NLR pyrin family domain containing 3 (NLRP3) inflammasome, respectively. The present study also investigated the regulatory mechanisms and associations between the TAK1 and JNK pathways, NOD‑, leucine‑rich repeat‑ and the NLRP3 inflammasome, in H9C2 cells and myocardial cells from the rat model of MI. LCZ696 improved MI‑induced myocardial fibrosis, rescued myocardial injury and suppressed the release of inflammatory factors. With regards to myocardial cell damage, pyroptosis in cardiomyocytes was observed. The in vitro experiments demonstrated that the overexpression of TAK1 promoted lysis of the N‑terminal of GSDMD, thereby activating the NLRP3 inflammasome and promoting the conversion of pro‑IL‑1β and pro‑IL‑18 into mature IL‑1β and IL‑18, respectively. In contrast, the silencing of TAK1 inhibited the expression levels of the NLRP3 inflammasome. In summary, LCZ696 reduced the expression levels of the NLRP3 inflammasome, suppressed inflammatory responses, improved the ventricular remodeling and exhibited protective effects in the MI heart by inhibiting the TAK1/JNK signaling pathway.

Comparative and Combinatorial Effects of Resveratrol and Sacubitril/Valsartan alongside Valsartan on Cardiac Remodeling and Dysfunction in MI-Induced Rats

The development and progression of heart failure (HF) due to myocardial infarction (MI) is a major concern even with current optimal therapy. Resveratrol is a plant polyphenol with cardioprotective properties. Sacubitril/valsartan is known to be beneficial in chronic HF patients. In this study, we investigated the comparative and combinatorial benefits of resveratrol with sacubitril/valsartan alongside an active comparator valsartan in MI-induced male Sprague Dawley rats. MI-induced and sham-operated animals received vehicle, resveratrol, sacubitril/valsartan, valsartan alone or sacubitril/valsartan + resveratrol for 8 weeks. Echocardiography was performed at the endpoint to assess cardiac structure and function. Cardiac oxidative stress, inflammation, fibrosis, brain natriuretic peptide (BNP), creatinine and neutrophil gelatinase associated lipocalin were measured. Treatment with resveratrol, sacubitril/valsartan, valsartan and sacubitril/valsartan + resveratrol significantly prevented left ventricular (LV) dilatation and improved LV ejection fraction in MI-induced rats. All treatments also significantly reduced myocardial tissue oxidative stress, inflammation and fibrosis, as well as BNP. Treatment with the combination of sacubitril/valsartan and resveratrol did not show additive effects. In conclusion, resveratrol, sacubitril/valsartan, and valsartan significantly prevented cardiac remodeling and dysfunction in MI-induced rats. The reduction in cardiac remodeling and dysfunction in MI-induced rats was mediated by a reduction in cardiac oxidative stress, inflammation and fibrosis.

Therapeutic Assessment of Combination Therapy with a Neprilysin Inhibitor and Angiotensin Type 1 Receptor Antagonist on Angiotensin II-Induced Atherosclerosis, Abdominal Aortic Aneurysms, and Hypertension

Combined neprilysin (NEP) inhibition (sacubitril) and angiotensin type 1 receptor (AT1R) antagonism (valsartan) is used in the treatment of congestive heart failure and is gaining interest for other angiotensin II (AngII)-related cardiovascular diseases. In addition to heart failure, AngII promotes hypertension, atherosclerosis, and abdominal aortic aneurysms (AAAs). Similarly, NEP substrates or products have broad effects on the cardiovascular system. In this study, we examined NEP inhibition (with sacubitril) and AT1R antagonism (with valsartan) alone or in combination on AngII-induced hypertension, atherosclerosis, or AAAs in male low-density lipoprotein receptor-deficient mice. Preliminary studies assessed drug delivery via osmotic minipumps for simultaneous release of sacubitril and/or valsartan with AngII over 28 days. Mice were infused with AngII (1000 ng/kg per minute) in the absence (vehicle) or presence of sacubitril (1, 6, or 9 mg/kg per day), valsartan (0.3, 0.5, 1, 6, or 20 mg/kg per day), or the combination thereof (1 and 0.3, or 9 or 0.5 mg/kg per day of sacubitril and valsartan, respectively). Plasma AngII and renin concentrations increased 4-fold at higher valsartan doses, indicative of removal of AngII negative feedback on renin. Sacubitril doubled plasma AngII concentrations at lower doses (1 mg/kg per day). Valsartan dose-dependently decreased systolic blood pressure, aortic atherosclerosis, and AAAs of AngII-infused mice, whereas sacubitril had no effect on atherosclerosis or AAAs but reduced blood pressure of AngII-infused mice. Combination therapy with sacubitril and valsartan did not provide additive benefits. These results suggest limited effects of combination therapy with NEP inhibition and AT1R antagonism against AngII-induced hypertension, atherosclerosis, or AAAs. SIGNIFICANCE STATEMENT: The combination of valsartan (angiotensin type 1 receptor antagonist) and sacubitril (neprilysin inhibitor) did not provide benefit above valsartan alone on AngII-induced hypertension, atherosclerosis, or abdominal aortic aneurysms in low-density lipoprotein receptor-deficient male mice. These results do not support this drug combination in therapy of these AngII-induced cardiovascular diseases.

Protective Effects of Sacubitril/Valsartan on Cardiac Fibrosis and Function in Rats With Experimental Myocardial Infarction Involves Inhibition of Collagen Synthesis by Myocardial Fibroblasts Through Downregulating TGF-β1/Smads Pathway

Objectives: To investigate the effect and mechanism of sacubitril/valsartan on myocardial fibrosis in rats following experimental myocardial infarction and in TGF-β1-treated myocardial fibroblasts.

Methods: Male Sprague-Dawley (SD) rats were subjected to coronary artery ligation to establish myocardial infarction and intragastrically fed vehicle, valsartan (Val, 32 mg/kg, once-daily) or sacubitril/valsartan (Sac/Val, 68 mg/kg, once-daily) for 4 weeks. In parallel, myocardial fibroblasts (MFs) isolated from neonatal SD rats were exposed to hypoxia and treated with TGF-β1 (5 ng/ml) plus vehicle, Val (10⁷–10^–5 M) or Sac/Val (10⁷–10⁵ M). Rat cardiac function and fibrosis were measured by echocardiography and histological method, respectively. MFs viability and collagen synthesis were determined by cell counting kit-8 and enzyme-linked immunosorbent assay, respectively. Protein expressions of TGF-β1, Smad3, phosphorylated Smad3 (p-Smad3), and p-Smad3 subcellular localization were detected by immunoblotting and immunocytochemistry.

Results: Sac/Val significantly improved cardiac structure and function in rats after myocardial infarction, including decreased left ventricular end-diastolic diameter and interventricular septal thickness, increased ejection fraction, and reduced myocardial collagen volume fraction and type Ⅰ and type Ⅲ collagen levels, and this effect was superior to that of Val. Besides, Sac/Val inhibited myocardial TGF-β1 and p-Smad3 protein expression better than Val. Mechanically, Sac/Val significantly attenuated TGF-β1-induced proliferation and collagen synthesis of MFs, and inhibit Smad3 phosphorylation and nucleus translocation, and this effect outperformed Val. Overexpression and silencing of Smad3 enhanced and reversed the inhibitory effects of Sac/Val on TGF-β1-induced collagen synthesis by MFs, respectively.

Conclusions: Sacubitril/valsartan improves cardiac function and fibrosis in rats after experimental myocardial infarction, and this effect is related to the inhibition of collagen synthesis in myocardial fibroblasts by inhibiting the TGF/Smads signaling pathway.

Combination of LCZ696 and ACEI further improves heart failure and myocardial fibrosis after acute myocardial infarction in mice

BACKGROUND

LCZ696, an angiotensin receptor-neprilysin inhibitor (ARNi), is reported to play a cardioprotective role after acute myocardial infarction (AMI). Angiotensin-converting enzyme inhibitors(ACEIs) have similar roles. However, it is unclear whether the combination of the two drugs has a better protective effect. The purpose of this study was to investigate the effect of this combination therapy after AMI.

METHODS

Male C57BL/6 J mice subjected to ligation of left anterior descending artery were treated for 4 weeks with LCZ696, ACEI(benazepril), or both(combination therapy) after induction of MI. Cardiac function, hemodynamics, and inflammatory factors were evaluated at 1 st day, 14th day, and 28th day. Heart weight and myocardial fibrosis were measured at the end of the experiment.

RESULTS

Blood pressure was lower in all treatment groups than in the control group. The combination therapy group had the strongest antihypertensive effect. Compared with LCZ696 or benazepril, treatment with combination therapy increased ejection fraction, fractional shortening, and cardiac output and decreased N-terminal pro-B-type natriuretic peptide(NT-proBNP). The ratios of heart weight to body weight in all treatment groups were less than that in the control group. Compared with the control and LCZ696 group, the fibrotic area in the combination therapy group was suppressed and had a lower level of TGF-β1 in the left ventricle. The plasma concentration of bradykinin and renin in the combination therapy group were highest among groups at 14th and 28th day.

CONCLUSIONS

LCZ696 in combination with benazepril showed better positive effects in modulating heart failure and myocardial fibrosis after acute AMI in mice and affect some inflammatory markers.

Immune regulation of cardiac fibrosis post myocardial infarction

Pathological changes resulting from myocardial infarction (MI) include extracellular matrix alterations of the left ventricle, which can lead to cardiac stiffness and impair systolic and diastolic function. The signals released from necrotic tissue initiate the immune cascade, triggering an extensive inflammatory response followed by reparative fibrosis of the infarct area. Immune cells such as neutrophils, monocytes, macrophages, mast cells, T-cells, and dendritic cells play distinct roles in orchestrating this complex pathological condition, and regulate the balance between pro-fibrotic and anti-fibrotic responses. This review discusses how molecular signals between fibroblasts and immune cells mutually regulate fibrosis post-MI, and outlines the emerging pharmacological targets and therapies for modulating inflammation and cardiac fibrosis associated with MI.

Dual Angiotensin Receptor-Neprilysin Inhibition With Sacubitril/Valsartan Attenuates Systolic Dysfunction in Experimental Doxorubicin-Induced Cardiotoxicity

BACKGROUND

Doxorubicin (DOX) induces cardiotoxicity in part by activation of matrix metalloproteinases (MMPs). Sacubitril/valsartan (Sac/Val) exerts additive cardioprotective actions over renin-angiotensin-aldosterone inhibitors in preclinical models of myocardial infarction and in heart failure patients. We hypothesized that Sac/Val would be more cardioprotective than Val in a rodent model of progressive DOX-induced cardiotoxicity, and this benefit would be associated with modulation of MMP activation.

OBJECTIVES

We sought to investigate the efficacy of Sac/Val for the treatment of anthracycline-induced cardiotoxicity.

METHODS

Male Wistar rats received DOX intraperitoneally (15 mg/kg cumulative) or saline over 3 weeks. Following the first treatment, control animals were gavaged daily with water (n = 25), while DOX-treated animals were gavaged daily with water (n = 25), Val (31 mg/kg; n = 25) or Sac/Val (68 mg/kg; n = 25) for either 4 or 6 weeks. Echocardiography was performed at baseline, and 4 and 6 weeks after DOX initiation. In addition, myocardial MMP activity was assessed with 99mTc-RP805, and cardiotoxicity severity was assessed by histology at these time points in a subgroup of animals.

RESULTS

Left ventricular ejection fraction decreased by 10% at 6 weeks in DOX and DOX + Val rats (both p < 0.05), while this reduction was attenuated in DOX + Sac/Val rats. MMP activity was increased at 6 weeks by 76% in DOX-alone rats, and tended to increase in DOX + Val rats (36%; p = 0.051) but was similar in DOX + Sac/Val rats as compared with time-matched control animals. Both therapies attenuated histological evidence of cellular toxicity and fibrosis (p < 0.05).

CONCLUSIONS

Sac/Val offers greater protection against left ventricular remodeling and dysfunction compared with standard angiotensin receptor blocker therapy in a rodent model of progressive DOX-induced cardiotoxicity.

Protection of Sacubitril/Valsartan against Pathological Cardiac Remodeling by Inhibiting the NLRP3 Inflammasome after Relief of Pressure Overload in Mice

Background/aims

The persistent existence of pathological cardiac remodeling, resulting from aortic stenosis, is related to poor clinical prognosis after successful transcatheter aortic valve replacement (TAVR). Sacubitril/valsartan (Sac/Val), comprising an angiotensin receptor blocker and a neprilysin inhibitor, has been demonstrated to have a beneficial effect against pathological cardiac remodeling, including cardiac fibrosis and inflammation in heart failure. The aim of this study was to determine whether Sac/Val exerts a cardioprotective effect after pressure unloading in mice.

Methods and results

Male C57BL/6 J mice were subjected to debanding (DB) surgery after 8 weeks (wk) of aortic banding (AB). Cardiac function was assessed by echocardiography, which indicated a protective effect of Sac/Val after DB. After treatment with Sac/Val post DB, decreased heart weight and myocardial cell size were observed in mouse hearts. In addition, histological analysis, immunofluorescence, and western blot results showed that Sac/Val attenuated cardiac fibrosis and inflammation after DB. Finally, our data indicated that Sac/Val treatment could significantly suppress NF-κB signaling and NLRP3 inflammasome activation in mice after relief of pressure overload.

Conclusion

Sac/Val exerted its beneficial effects to prevent maladaptive cardiac fibrosis and dysfunction in mice following pressure unloading, which was at least partly due to the inhibition of NLRP3 inflammasome activation.

Electronic supplementary material

The online version of this article (10.1007/s10557-020-06995-x) contains supplementary material, which is available to authorized users.

Systematic examination of a heart failure risk prediction tool: The pooled cohort equations to prevent heart failure

Identification of individuals at risk for heart failure is needed to deliver targeted preventive strategies and maximize net benefit of interventions. To examine the clinical utility of the recently published heart failure-specific risk prediction model, the Pooled Cohort Equations to Prevent Heart Failure, we sought to demonstrate the range of risk values associated with diverse risk factor combinations in White and Black men and women. We varied individual risk factors while holding the other risk factors constant at age-adjusted national mean values for risk factors in each race-sex and age group. We also examined multiple combinations of risk factor levels and examined the range of predicted 10-year heart failure risk using the Pooled Cohort Equations to Prevent Heart Failure risk tool. Ten-year predicted heart failure risk varied widely for each race-sex group across a range of ages and risk factor scenarios. For example, predicted 10-year heart failure risk in a hypothetical 40 year old varied from 0.1% to 9.7% in a White man, 0.5% to 12.3% in a Black man, <0.1% to 9.3% in a White woman, and 0.2% to 28.0% in a Black woman. Higher risk factor burden (e.g. diabetes and hypertension requiring treatment) consistently drove higher risk estimates in all race-sex groups and across all ages. Our analysis highlights the importance of a race and sex-specific multivariable risk prediction model for heart failure to personalize the clinician-patient discussion, inform future practice guidelines, and provide a framework for future risk-based prevention trials for heart failure.

cGMP Signaling and Modulation in Heart Failure

Cyclic GMP (cGMP) represents a classic intracellular second messenger molecule. Over the past 2 decades, important discoveries have identified that cGMP signaling becomes deranged in heart failure (HF) and that cGMP and its main kinase effector, protein kinase G, generally oppose the biological abnormalities contributing to HF, in experimental studies. These findings have influenced the design of clinical trials of cGMP-augmenting drugs in HF patients. At present, the trial results of cGMP-augmenting therapies in HF remain mixed. As detailed in this review, strong evidence now exists that protein kinase G opposes pathologic cardiac remodeling through regulation of diverse biological processes and myocardial substrates. Potential reasons for the failures of cGMP-augmenting drugs in HF may be related to biological mechanisms opposing cGMP or because of certain features of clinical trials, all of which are discussed.

Natriuretic peptides and neprilysin inhibition in hypertension and hypertensive organ damage

The family of natriuretic peptides (NPs) discovered in mammalian tissues including cardiac atrium and brain consists of three members, namely, atrial, B- and C-type natriuretic peptides (ANP, BNP, CNP). Since the discovery, basic and clinical studies have been vigorously performed to explore the biological functions and pathophysiological roles of NPs in a wide range of diseases including hypertension and heart failure. These studies revealed that ANP and BNP are hormones secreted from the heart into the blood stream in response to pre- or after-load, counteracting blood pressure (BP) elevation and fluid retention through specific receptors. Meanwhile, CNP was found to be produced by the vascular endothelium, acting as a local mediator potentially serving protective functions for the blood vessels. Because NPs not only exert blood pressure lowering actions but also alleviate hypertensive organ damage, attempts have been made to develop therapeutic agents for hypertension by utilizing this family of NPs. One strategy is to inhibit neprilysin, an enzyme degrading NPs, thereby enhancing the actions of endogenous peptides. Recently, a dual inhibitor of angiotensin receptor-neprilysin was approved for heart failure, and neprilysin inhibition has also been shown to be beneficial in treating patients with hypertension. This review summarizes the roles of NPs in regulating BP, with special references to hypertension and hypertensive organ damage, and discusses the therapeutic implications of neprilysin inhibition.

The Rationale of Neprilysin Inhibition in Prevention of Myocardial Ischemia-Reperfusion Injury during ST-Elevation Myocardial Infarction

During the last three decades, timely myocardial reperfusion using either thrombolytic therapy or primary percutaneous intervention (pPCI) has allowed amazing improvements in outcomes with a more than halving in 1-year ST-elevation myocardial infarction (STEMI) mortality. However, mortality and left ventricle (LV) remodeling remain substantial in these patients. As such, novel therapeutic interventions are required to reduce myocardial infarction size, preserve LV systolic function, and improve survival in reperfused-STEMI patients. Myocardial ischemia-reperfusion injury (MIRI) prevention represents the main goal to reach in order to reduce STEMI mortality. There is currently no effective therapy for MIRI prevention in STEMI patients. A significant reason for the weak and inconsistent results obtained in this field may be the presence of multiple, partially redundant, mechanisms of cell death during ischemia-reperfusion, whose relative importance may depend on the conditions. Therefore, it is always more recognized that it is important to consider a "multi-targeted cardioprotective therapy", defined as an additive or synergistic cardioprotective agents or interventions directed to distinct targets with different timing of application (before, during, or after pPCI). Given that some neprilysin (NEP) substrates (natriuretic peptides, angiotensin II, bradykinin, apelins, substance P, and adrenomedullin) exert a cardioprotective effect against ischemia-reperfusion injury, it is conceivable that antagonism of proteolytic activity by this enzyme may be considered in a multi-targeted strategy for MIRI prevention. In this review, by starting from main pathophysiological mechanisms promoting MIRI, we discuss cardioprotective effects of NEP substrates and the potential benefit of NEP pharmacological inhibition in MIRI prevention.

LCZ696 Ameliorates Oxidative Stress and Pressure Overload-Induced Pathological Cardiac Remodeling by Regulating the Sirt3/MnSOD Pathway

Aims

We aimed to investigate whether LCZ696 protects against pathological cardiac hypertrophy by regulating the Sirt3/MnSOD pathway.

Methods

In vivo, we established a transverse aortic constriction animal model to establish pressure overload-induced heart failure. Subsequently, the mice were given LCZ696 by oral gavage for 4 weeks. After that, the mice underwent transthoracic echocardiography before they were sacrificed. In vitro, we introduced phenylephrine to prime neonatal rat cardiomyocytes and small-interfering RNA to knock down Sirt3 expression.

Results

Pathological hypertrophic stimuli caused cardiac hypertrophy and fibrosis and reduced the expression levels of Sirt3 and MnSOD. LCZ696 alleviated the accumulation of oxidative reactive oxygen species (ROS) and cardiomyocyte apoptosis. Furthermore, Sirt3 deficiency abolished the protective effect of LCZ696 on cardiomyocyte hypertrophy, indicating that LCZ696 induced the upregulation of MnSOD and phosphorylation of AMPK through a Sirt3-dependent pathway.

Conclusions

LCZ696 may mitigate myocardium oxidative stress and apoptosis in pressure overload-induced heart failure by regulating the Sirt3/MnSOD pathway.

The Role of Natriuretic Peptides in the Regulation of Cardiac Tolerance to Ischemia/Reperfusion and Postinfarction Heart Remodeling

In the past 10 years, mortality from acute myocardial infarction has not decreased despite the widespread introduction of percutaneous coronary intervention. The reason for this situation is the absence in clinical practice of drugs capable of preventing reperfusion injury of the heart with high efficiency. In this regard, noteworthy natriuretic peptides (NPs) which have the infarct-limiting effect, prevent reperfusion cardiac injury, prevent adverse post-infarction remodeling of the heart. Atrial natriuretic peptide does not have the infarct-reducing effect in rats with alloxan-induced diabetes mellitus. NPs have the anti-apoptotic and anti-inflammatory effects. There is indirect evidence that NPs inhibit pyroptosis and autophagy. Published data indicate that NPs inhibit reactive oxygen species production in cardiomyocytes, aorta, heart, kidney and the endothelial cells. NPs can suppress aldosterone, angiotensin II, endothelin-1 synthesize and secretion. NPs inhibit the effects aldosterone, angiotensin II on the post-receptor level through intracellular signaling events. NPs activate guanylyl cyclase, protein kinase G and protein kinase A, and reduce phosphodiesterase 3 activity. NO-synthase and soluble guanylyl cyclase are involved in the cardioprotective effect of NPs. The cardioprotective effect of natriuretic peptides is mediated via activation of kinases (AMPK, PKC, PI3 K, ERK1/2, p70s6 k, Akt) and inhibition of glycogen synthase kinase 3β. The cardioprotective effect of NPs is mediated via sarcolemmal K_ATP channel and mitochondrial K_ATP channel opening. The cardioprotective effect of brain natriuretic peptide is mediated via MPT pore closing. The anti-fibrotic effect of NPs may be mediated through inhibition TGF-β1 expression. Natriuretic peptides can inhibit NF-κB activity and activate GATA. Hemeoxygenase-1 and peroxisome proliferator-activated receptor γ may be involved in the infarct-reducing effect of NPs. NPs exhibit the infarct-limiting effect in patients with acute myocardial infarction. NPs prevent post-infarction remodeling of the heart. To finally resolve the question of the feasibility of using NPs in AMI, a multicenter, randomized, blind, placebo-controlled study is needed to assess the effect of NPs on the mortality of patients after AMI.

Effects of sacubitril/valsartan on ventricular remodeling in patents with left ventricular systolic dysfunction following acute anterior wall myocardial infarction

OBJECTIVE

The aim of this study was to investigate the effect of sacubitril/valsartan (Sal/Val) on left ventricular (LV) remodeling in patients with LV systolic dysfunction following acute anterior wall myocardial infarction (AAMI).

METHODS

AAMI patients with LV systolic dysfunction were enrolled in this study. All patients underwent percutaneous coronary intervention. After hemodynamic stabilization, patients were randomly assigned either to group T (Sal/Val treatment) or group C (enalapril treatment). Changes in echocardiographic parameters and plasma biochemical markers were used to evaluate the effects of Sal/Val on LV remodeling and cardiac function. The incidence of major cardiac adverse events (MACEs) and adverse reactions during follow-ups was also recorded.

RESULTS

In total, 137 eligible patients were prospectively included. Compared to group C, LV ejection fraction significantly improved (P < 0.05), while the LV end-systolic volume index and wall motion score index showed a tendency to decrease in group T. There was no difference in the LV end-diastolic volume index between groups. During follow-ups, the plasma N-terminal pro-B-type natriuretic peptide and soluble suppression of tumorigenesis-2 levels in both groups decreased (all P < 0.05), and the change was more prominent in group T. Additionally, drug-related adverse effects were similar between the two groups (P > 0.05); however, the incidence of MACEs was lower in group T than in group C (39.71% vs. 53.62%, P = 0.103), although the difference was insignificant.

CONCLUSION

Sac/Val attenuated LV remodeling and dysfunction and was safe and effective in LV systolic dysfunction patients post AAMI.

Current evidence of sacubitril/valsartan in the treatment of heart failure with reduced ejection fraction

Heart failure (HF) is one of the most common reasons for hospital admission in western countries. The measurement of the left ventricular ejection fraction is essential for the classification of HF and deciding on HF treatment. The treatment of HF has been improved in both diagnostic and therapeutic fields over the past two decades. The angiotensin receptor-neprilysin inhibitor decreased the cardiovascular mortality in patients with chronic HF with reduced ejection fraction. Sacubitril/valsartan (LCZ696) improves the imbalance between the renin-angiotensin-aldosterone and natriuretic peptide systems. We present the clinical efficacy, real-world experience, safety and tolerability, the relevance of etiology of cardiomyopathy, and gender differences and regulatory affairs of LCZ696 in the treatment of patients with HF with reduced ejection fraction.

Sacubitril/Valsartan Improves Left Ventricular Function in Chronic Pressure Overload Independent of Intact Cyclic Guanosine Monophosphate-dependent Protein Kinase I Alpha Signaling

BACKGROUND

Combined angiotensin receptor/neprilysin inhibition with sacubitril/valsartan (Sac/Val) has emerged as a therapy for heart failure. The presumed mechanism of benefit is through prevention of natriuretic peptide degradation, leading to increased cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG) signaling. However, the specific requirement of PKG for Sac/Val effects remains untested.

METHODS AND RESULTS

We examined Sac/Val treatment in mice with mutation of the cGMP-dependent protein kinase I (PKGI)α leucine zipper domain, which is required for cGMP-PKGIα antiremodeling actions in vivo. Wild-type (WT) or PKG leucine zipper mutant (LZM) mice were exposed to 56-day left ventricular (LV) pressure overload by moderate (26G) transaortic constriction (TAC). At day 14 after TAC, mice were randomized to vehicle or Sac/Val by oral gavage. TAC induced the same degree of LV pressure overload in WT and LZM mice, which was not affected by Sac/Val. Although LZM mice, but not WT, developed LV dilation after TAC, Sac/Val improved cardiac hypertrophy and LV fractional shortening to the same degree in both the WT and LZM TAC mice.

CONCLUSION

These findings indicate the beneficial effects of Sac/Val on LV structure and function in moderate pressure overload. The unexpected finding that PKGIα mutation does not abolish the Sac/Val effects on cardiac hypertrophy and on LV function suggests that signaling other than natriuretic peptide- cGMP-PKG mediates the therapeutic benefits of neprilysin inhibition in heart failure.

Sacubitril/valsartan attenuates atrial electrical and structural remodelling in a rabbit model of atrial fibrillation

Atrial structural and electrical remodelling play important roles in atrial fibrillation (AF). Sacubitril/valsartan attenuates cardiac remodelling in heart failure. However, the effect of sacubitril/valsartan on AF is unclear. The aim of this study was to evaluate the effect of sacubitril/valsartan on atrial electrical and structural remodelling in AF and investigate the underlying mechanism of action. Thirty-three rabbits were randomized into sham, RAP, and sac/val groups. HL-1 cells were subjected to control treatment or rapid pacing with or without LBQ657 and valsartan. Echocardiography, atrial electrophysiology, and histological examination were performed. The concentration of Ca²⁺ and expression levels of calcineurin, NFAT, p-NFAT, Cav1.2, collagen Ⅰ and Ⅲ, ANP, BNP, CNP, NT-proBNP, and ST2 in HL-1 cells, and I_caL in left atrial cells, were determined. We observed that compared to that in the sham group, the atrium and right ventricle were enlarged, myocardial fibrosis was markedly higher, AF inducibility was significantly elevated, and atrial effective refractory periods were shortened in the RAP group. These effects were significantly reversed by sacubitril/valsartan. Compared to that in the sham group, collagen Ⅰ and Ⅲ, NT-proBNP, ST2, calcineurin, and NFAT were significantly up-regulated, while p-NFAT and Ca_v1.2 were down-regulated in the RAP group, and sacubitril/valsartan inhibited these changes. Ca²⁺ concentration increased and I_CaL density decreased in in vivo and in vitro AF models, reversed by sacubitril/valsartan. Sacubitril/valsartan attenuates atrial electrical remodelling and ameliorates structure remodelling in AF. This study paves the way for the possibility of clinical use of sacubitril/valsartan in AF patients.