LCZ696, Angiotensin II Receptor-Neprilysin Inhibitor, Ameliorates High-Salt-Induced Hypertension and Cardiovascular Injury More Than Valsartan Alone

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.

Effects of sacubitril-valsartan on remodelling, fibrosis and mitochondria in a murine model of isoproterenol-induced left ventricular dysfunction

BACKGROUND

Sacubitril/valsartan has been demonstrated to promote left ventricular (LV) reverse remodelling and improve outcomes in patients with heart failure (HF) with reduced ejection fraction (EF). Its molecular and tissue effects have not been fully elucidated yet, due to the paucity of preclinical studies, mostly based on ischaemic models. We aimed to evaluate the effects of sacubitril/valsartan on LV remodelling, myocardial fibrosis and mitochondrial biology in a murine model of non-ischaemic LV dysfunction.

METHODS

Adult transgenic male mice with cardiac-specific hyperaldosteronism (AS mice) received subcutaneous isoproterenol injections to induce LV systolic dysfunction. After 7 days, mice were randomized to a 2-week treatment with saline (ISO-AS n = 15), valsartan (ISO + V n = 12) or sacubitril/valsartan (ISO + S/V n = 12). Echocardiography was performed at baseline, at day 7, and after each of the 2 weeks of treatment. After sacrifice at day 21, histological and immunochemical assays were performed. A control group of AS mice was also obtained (Ctrl-AS n = 8).

RESULTS

Treatment with sacubitril/valsartan, but not with valsartan, induced a significant improvement in LVEF (p = 0.009 vs ISO-AS) and fractional shortening (p = 0.032 vs ISO-AS) after 2- week treatment. In both ISO + V and ISO + S/V groups, a trend toward reduction of the cardiac collagen 1/3 expression ratio was detected. ISO + V and ISO + S/V groups showed a significant recovery of mitochondrial morphology and inner membrane function meant for oxidative phosphorylation.

CONCLUSION

In a murine model of non-ischaemic HF, sacubitril/valsartan proved to have beneficial effects on LV systolic function, and on cardiac energetics, by improving mitochondrial activity.

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.

Clinical Benefit of Sacubitril/Valsartan for Hypertensive Patients in Daily Practice and Predictors of Its Antihypertensive Effect

Background: The blood pressure (BP)-lowering effect of sacubitril/valsartan (Sac/Val) is greater than that of angiotensin II receptor blockers (ARBs) but in in real-world clinical practice, Sac/Val is used in a variety of patterns other than switching from ARBs. In the present study we investigated the effects of Sac/Val on BP and biochemical parameters when switching from or adding it to various antihypertensive drugs and examined what factors could be predictors of the antihypertensive effect of Sac/Val. Methods and Results: In 108 hypertensive patients treated with antihypertensive agents (including 4 naïve cases), clinic BP and various biochemical parameters were assessed before and after switching to/adding Sac/Val (200 mg/day). Systolic and diastolic BPs significantly decreased after treatment with Sac/Val (P<0.0001, respectively). As for biochemical parameters, alanine aminotransferase, triglycerides, C-reactive protein, and uric acid significantly decreased after administration of Sac/Val, but renal function, B-type natriuretic peptide, and plasma renin activity (PRA) did not change before or after treatment with Sac/Val. Multiple regression analysis revealed that low PRA and high baseline systolic BP were independent determinants of systolic BP reduction after Sac/Val treatment. Conclusions: Sac/Val is beneficial for poorly controlled hypertension in daily clinical practice and low PRA may be a predictor of the antihypertensive effect of switching to/adding Sac/Val.

Valsartan Mitigates the Progression of Methotrexate-Induced Acute Kidney Injury in Rats via the Attenuation of Renal Inflammation and Oxidative Stress

Background

Methotrexate (MTX) is a folic acid antagonist, commonly administered for the treatment of a variety of cancers. However, methotrexate toxicity including bone marrow suppression and hepatic and renal toxicity limits its use. Angiotensin AT1 receptor blockers including Valsartan (Val) possess the ability to ameliorate MTX-induced toxicity through various mechanisms. In this study, we explored the potential reno-protective effects of Val against MTX-induced acute kidney injury in rats.

Methods

Twenty-four Wistar rats were randomly segregated into 3 groups. Group 1 served as the control group and received an oral dose of 1mL/kg of normal saline. Group 2 received a single dose of 20 mg/kg of MTX intraperitoneally (IP) for 5 days. Group 3 received a single IP dose of 20 mg/kg of MTX followed by an oral dose of 10 mg/kg of Valsartan for 5 days. At the end of the experiment, the levels of serum kidney biomarkers, inflammatory and oxidative stress markers were accessed. Furthermore, the effect of MTX on kidney tissue histology was examined.

Results and discussion

Our results showed that MTX treatment increased the level of serum kidney and inflammatory biomarkers and decreased the level of antioxidants SOD and GSH while increasing the lipid peroxidation contents. Furthermore, MTX treatment caused structural changes to kidney histology. However, the administration of Val significantly prevented these changes.

Conclusion

Valsartan possesses nephroprotective potential and might serve as a potential therapeutic strategy against MTX-induced kidney injury.

Protective effect of novel angiotensin receptor neprilysin inhibitor S086 on target organ injury in spontaneously hypertensive rats

BACKGROUND

Hypertension is a clinical syndrome characterized by elevated systemic arterial blood pressure associated with injury to the heart, kidney, brain, and other organs. Angiotensin receptor neprilysin inhibitors (ARNi), including angiotensin receptor blockers (ARBs) and neprilysin inhibitors (NEPi), have been shown to be safe and effective at reducing blood pressure and alleviating development of target organ injury. This study was used to develop S086 as a novel ARNi and conducted preclinical studies in animal models to evaluate the protective effects of S086 on target organs.

METHODS

This study used a 14-month-old spontaneously hypertensive rat (SHR) model to evaluate the protective effects of S086 on the cardiovascular system and organs such as heart and kidney by blood pressure monitoring, urine and blood examination, pathological examination, and immunological index detection.

RESULTS

After administering S086 orally to the SHR, their blood pressure and levels of renal injury indicators such as serum creatinine and urinary microalbumin were reduced, and myocardial cell necrosis and cardiac fibrosis of the heart were significantly improved. In addition, there were also significantly improvements in the histological lesions of blood vessels and the kidneys.

CONCLUSIONS

The findings showed that S086 effectively reduced the blood pressure of SHR and had effects on alleviating development of heart, blood vessels and kidney.

Sacubitril/valsartan reverses cardiac structure and function in experimental model of hypertension-induced hypertrophic cardiomyopathy

This study evaluated the effect of sacubtril/valsartan on cardiac remodeling, molecular and cellular adaptations in experimental (rat) model of hypertension-induced hypertrophic cardiomyopathy. Thirty Wistar Kyoto rats, 10 healthy (control) and 20 rats with confirmed hypertension-induced hypertrophic cardiomyopathy (HpCM), were used for this study. The HpCM group was further subdivided into untreated and sacubitril/valsartan-treated groups. Myocardial structure and function were assessed using echocardiography, Langendorff's isolated heart experiment, blood sampling and qualitative polymerase chain reaction. Echocardiographic examinations revealed protective effects of sacubitril/valsartan by improving left ventricular internal diameter in systole and diastole and fractional shortening. Additionally, sacubitril/valsartan treatment decreased systolic and diastolic blood pressures in comparison with untreated hypertensive rats. Moreover, sacubitril/valsartan treatment reduced oxidative stress and apoptosis (reduced expression of Bax and Cas9 genes) compared to untreated rats. There was a regular histomorphology of cardiomyocytes, interstitium, and blood vessels in treated rats compared to untreated HpCM rats which expressed hypertrophic cardiomyocytes, with polymorphic nuclei, prominent nucleoli and moderately dilated interstitium. In experimental model of hypertension-induced hypertrophic cardiomyopathy, sacubitril/valsartan treatment led to improved cardiac structure, haemodynamic performance, and reduced oxidative stress and apoptosis. Sacubitril/valsartan thus presents as a potential therapeutic strategy resulted in hypertension-induced hypertrophic cardiomyopathy.

Dual angiotensin receptor and neprilysin inhibitor reduced portal pressure through peripheral vasodilatation and decreasing systemic arterial pressure in cirrhotic rats

BACKGROUND

Portal hypertension develops along with the progression of liver cirrhosis. Natriuretic peptides have been shown to reduce portal pressure but concomitantly activate the renin-angiotensin-aldosterone system (RAAS). Angiotensin receptor-neprilysin inhibitors (ARNIs) upregulate natriuretic peptides and avoid the adverse effects of RAAS activation. ARNIs have been shown to reduce portal pressure in rats with pre-hepatic portal hypertension, which involves relatively little liver injury. This study aimed to evaluate the relevant effects of an ARNI in rats with both liver cirrhosis and portal hypertension.

METHODS

Male Sprague-Dawley rats received common bile duct ligation to induce liver cirrhosis and portal hypertension. Sham-operated rats served as surgical controls. All rats were randomly allocated into three groups to receive distilled water (vehicle), LCZ696 (an ARNI), or valsartan for 4 weeks. Portal hypertension and relevant derangements were assessed after treatment.

RESULTS

Portal hypertension and hyperdynamic circulation developed in the cirrhotic rats. In the rats with cirrhosis and portal hypertension, both LCZ696 and valsartan reduced portal hypertension, mean arterial pressure, and systemic vascular resistance. The decrease in portal pressure was highly associated with the reduction in arterial pressure and systemic vascular resistance. Blood flow in hepatic, splanchnic, and portosystemic collateral systems was not altered. LCZ696 did not significantly influence liver injury or plasma cytokine levels. Liver fibrosis and splanchnic angiogenesis were not affected.

CONCLUSION

ARNI treatment exerted portal pressure lowering effects via peripheral vasodilatation and decreasing systemic arterial pressure in the rats with liver cirrhosis and portal hypertension. Caution should be taken when using ARNIs in liver cirrhosis.

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.

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.

Study of the possible effect of sacubitril/valsartan combination versus valsartan on the cognitive function in Alzheimer's disease model in rats

Objectives: Alzheimer's disease (AD) is an irreversible, progressive neurodegenerative disorder. The proportion of elderly individuals at risk for AD and cardiovascular problems increases by raising life expectancy. The present study was designed to investigate the effect of the sacubitril/valsartan combination compared to that of valsartan alone in a rat model of AD. Methods: 72 male adult Wistar rats were divided into seven groups; control untreated rats received saline, control valsartan-treated rats received valsartan orally, control sacubitril/valsartan treated rats received sacubitril/valsartan orally, model rats received aluminum chloride i.p., model valsartan treated rats received aluminum chloride i.p. and valsartan orally and model sacubitril/valsartan treated rats received aluminum chloride i.p. and sacubitril/valsartan combination orally. All previous treatments continued on a daily basis for 6 weeks. At the second, fourth, and sixth weeks of the experiment, behavioral changes were evaluated using the Morris water maze and novel object recognition tests, and systolic blood pressure was measured. In the end, rat brain malondialdehyde and amyloid-beta 1-42 levels were measured, and the isolated hippocampus was evaluated histopathologically. Results: Valsartan improved AD symptoms in the aluminum-induced rat model, while the sacubitril/valsartan combination significantly worsened all tested parameters in both control and model rats compared with untreated and valsartan-treated animals. Conclusion: Based on the current study's findings, valsartan did not increase the risk for AD development in control rats and improved AD symptoms in a rat model, while sacubitril/valsartan combination increased the risk of AD in control rats and worsened the condition in a rat model.

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.

Clinical evidence of Xinbao Pills efficacy on chronic heart failure patients: A protocol for systematic review and meta-analysis

BACKGROUND

Chronic heart failure (CHF) is a common cardiovascular disease and results in high rate of morbidity, mortality, hospitalizations, and disability, causing medical concern around the world. Xinbao Pill (XBP) has been widely applied to clinical practice for patients with CHF but lacks studies to verify its efficacy. This study provides a protocol of systematic review, with which we will verify the adjunctive efficacy and safety of XBP on CHF with evidence-based studies.

METHODS

Included studies will be retrieved according to inclusion and exclusion criteria from five English databases (the MEDLINE via PubMed, the Cochrane Library, EMBASE, the Web of Science and Ovid database), and four Chinese databases (China Science and Technology Journal Database [VIP], Chinese Biomedical Literature Database [CBM], Wan-fang Database, China National Knowledge Infrastructure [CNKI]) from October 1990 to October 2018. The New York Heart Association (NYHA), heart rate and mortality will be marked as major outcomes. We will use RevMan V.5.3 software to calculate the data synthesis and will conduct meta-analysis based on the collected data.

RESULTS

Mortality, NYHA function classification, heart rate, the left ventricular ejection fractions (LVEF), 6-minute walk test (6MWT), hospitalization or rehospitalization, NT-proBNP, and adverse effects will be measured and comprehensively assessed to evaluate the adjunctive effect of XBP on CHF from this systematic review and meta-analysis with current clinical evidence.

CONCLUSION

The systematic review and meta-analysis will assess the adjunctive effect of XBP in the treatment of CHF with up-to-date clinical evidence.

LCZ696 ameliorates doxorubicin-induced cardiomyocyte toxicity in rats

Doxorubicin (DOX)-based chemotherapy induces cardiotoxicity, which is considered the main bottleneck for its clinical application. In this study, we investigated the potential benefit of LCZ696, an angiotensin receptor-neprilysin inhibitor against DOX-induced cardiotoxicity in rats and H9c2 cells and determined whether the mechanism underlying any such effects involves its antioxidant activity. Male Sprague-Dawley rats were randomly separated into four groups, each consisting of 15 rats (DOX (1.5 mg/kg/day intraperitoneally for 10 days followed by non-treatment for 8 days); DOX + valsartan (31 mg/kg/day by gavage from day 1 to day 18); DOX + LCZ696 (68 mg/kg/day by gavage from day 1 to day 18); and control (saline intraperitoneally for 10 days). DOX-induced elevation of cardiac troponin T levels on day 18 was significantly reduced by LCZ696, but not valsartan. The DOX-induced increase in myocardial reactive oxygen species (ROS) levels determined using dihydroethidium was significantly ameliorated by LCZ696, but not valsartan, and was accompanied by the suppression of DOX-induced increase in p47phox. LCZ696 recovered the DOX-induced decrease in phosphorylation of adenosine monophosphate-activated protein kinase and increased the ratio of Bax and Bcl-2. In H9c2 cardiomyocytes, LCZ696 reduced DOX-induced mitochondrial ROS generation and improved cell viability more than valsartan. Our findings indicated that LCZ696 ameliorated DOX-induced cardiotoxicity in rat hearts in vivo and in vitro, possibly by mediating a decrease in oxidative stress.

Combining Neprilysin Inhibitor With AT2R Agonist Is Superior to Combination With AT1R Blocker in Providing Reno-Protection in Obese Rats

Clinical use of the combination therapy of the neprilysin inhibitor sacubitril and angiotensin II type 1 receptor blocker valsartan is known to be associated with albuminuria. Albuminuria is both a risk factor for and an indicator of kidney injury. Earlier work from our laboratory reported that the agonist of angiotensin II type 2 receptor Compound 21 (C21) prevents proteinuria, albuminuria, and is reno-protective in obese Zucker rats fed high salt diet (HSD). Thus, we hypothesized that sacubitril/C21 combination provides superior reno-protection compared to sacubitril/valsartan. Male obese Zucker rats 10–11 weeks old were treated daily with vehicle, sacubitril + C21, or sacubitril + valsartan while fed HSD for 16 days. HSD-feeding caused kidney dysfunction, evident by significant increases in urinary protein, osteopontin, and cystatin C. HSD-feeding lowered plasma cystatin C and creatinine concentrations suggestive of hyperfiltration, which was not affected by either treatment. Unlike sacubitril/valsartan, sacubitril/C21 treatment significantly decreases proteinuria, albuminuria, the expression of nephrin, and kidney weight, independent of hyperfiltration, compared with HSD alone. Moreover, sacubitril/valsartan therapy increased plasma renin and did not prevent HSD-induced increases in renal angiotensin II, while sacubitril/C21 completely prevented these changes. Together, this study suggests that sacubitril/C21 afforded superior reno-protection compared to sacubitril/valsartan therapy in high salt-fed obese Zucker rats.

Efficacy of sacubitril/valsartan versus olmesartan in Japanese patients with essential hypertension: a randomized, double-blind, multicenter study

This phase III study assessed the efficacy and safety of sacubitril/valsartan compared with those of olmesartan in Japanese patients with essential hypertension. Patients (n = 1161, aged ≥20 years) with mild to moderate hypertension (mean sitting systolic blood pressure [msSBP] ≥150 to <180 mmHg) were randomized to receive sacubitril/valsartan 200 mg (n = 387), sacubitril/valsartan 400 mg (n = 385), or olmesartan 20 mg (n = 389) once daily for 8 weeks. The primary assessment was a reduction in msSBP from baseline with sacubitril/valsartan 200 mg vs. olmesartan 20 mg at Week 8. Secondary assessments included msSBP reduction with sacubitril/valsartan 400 mg vs. olmesartan at Week 8 and reductions in mean sitting diastolic blood pressure (msDBP), mean sitting pulse pressure (msPP), and overall blood pressure (BP) control rate for all treatment groups at Week 8. Sacubitril/valsartan 200 mg provided a significantly greater reduction in msSBP from baseline than olmesartan at Week 8 (between-treatment difference: −5.01 mmHg [95% confidence interval: −6.95 to −3.06 mmHg, P < 0.001 for noninferiority and superiority]). Greater reductions in msSBP with sacubitril/valsartan 400 mg vs. olmesartan, as well as in msDBP and msPP with both doses of sacubitril/valsartan vs. olmesartan (P < 0.05 for all), were also observed. Patients treated with sacubitril/valsartan achieved an overall higher BP control rate. The safety and tolerability profiles of sacubitril/valsartan were generally comparable to those of olmesartan. The adverse event rate with sacubitril/valsartan was not dose-dependent. Treatment with sacubitril/valsartan was effective and provided superior BP reduction, with a higher proportion of patients achieving target BP goals than treatment with olmesartan in Japanese patients with mild to moderate essential hypertension.

Treatment with sacubitril/valsartan is effective and provided superior blood pressure (BP) reductions with a higher proportion of patients achieving target BP goals versus olmesartan in Japanese patients with mild-to-moderate essential hypertension.

Sympathoinhibitory effect of sacubitril-valsartan in heart failure with reduced ejection fraction: A pilot study

Chronic sympathetic nervous system (SNS) overactivity, characteristic of heart failure (HF) with reduced ejection fraction (HFrEF), is associated with poor prognosis and contributes to increased mortality risk. Sacubitril-valsartan is a recently approved, first-in-class, angiotensin receptor neprilysin inhibitor (ARNI) drug that markedly reduces the risks of death from cardiovascular causes and hospitalization for HF in patients with HFrEF, but the physiological mechanisms underlying these benefits are not fully understood. This single-arm, open-label, prospective study sought to test the hypothesis that short-term treatment with sacubitril-valsartan reduces SNS activity, measured directly via muscle sympathetic nerve activity (MSNA), in patients with HFrEF. MSNA, heart rate (HR), and arterial blood pressure (BP) were assessed in stable Class II and III patients with HFrEF (n = 9, 69 ± 8 yrs.; 28.6 ± 3.6 kg/m²) on contemporary, guideline-directed medical treatment who were subsequently started on sacubitril-valsartan. These measurements were repeated after two months of treatment with sacubitril-valsartan. Sacubitril-valsartan reduced MSNA burst frequency (baseline: 43 ± 10 bursts/min; 2-month: 36 ± 10 bursts/min, p = 0.05) and burst incidence (baseline: 68 ± 16 bursts/100 heartbeats; 2-month: 55 ± 16 bursts/100 heartbeats, p = 0.02), while HR and BP were unchanged following of treatment (p > 0.05). These preliminary findings provide new evidence regarding the ability of sacubitril-valsartan to rapidly reduce SNS activity in patients with HFrEF, suggesting the presence of a novel sympathoinhibitory effect of this new drug class.

Acute pulmonary pressure change after transition to sacubitril/valsartan in patients with heart failure reduced ejection fraction

Aims

Sacubitril/valsartan combines renin–angiotensin–aldosterone system inhibition with amplification of natriuretic peptides. In addition to well‐described effects, natriuretic peptides exert direct effects on pulmonary vasculature. The effect of sacubitril/valsartan on pulmonary artery pressure (PAP) has not been fully defined.

Methods and results

This was a retrospective case‐series of PAP changes following transition from angiotensin‐converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) to sacubitril/valsartan in patients with heart failure reduced ejection fraction and a previously implanted CardioMEMS™ sensor. Pre‐sacubitril/valsartan and post‐sacubitril/valsartan PAPs were compared for each patient by examining averaged consecutive daily pressure readings from 1 to 5 days before and after sacubitril/valsartan exposure. PAP changes were also compared between patients based on elevated trans‐pulmonary gradients (trans‐pulmonary gradient ≥ 12 mmHg) at time of CardioMEMS™ sensor implantation. The cohort included 18 patients, 72% male, mean age 60.1 ± 13.6 years. There was a significant decrease in PAPs associated with transition from ACEI/ARB to sacubitril/valsartan. The median (interquartile range) pre‐treatment and post‐treatment change in mean, systolic and diastolic PAPs were −3.6 (−9.8, −0.7) mmHg (P < 0.001), −6.5 (−15.0, −2.0) mmHg (P = 0.001), and −2.5 (−5.7, −0.7) (P = 0.001), respectively. The decrease in PAPs was independent of trans‐pulmonary gradient (F(1,16) = 0.49, P = 0.49).

Conclusions

In this retrospective case series, transition from ACEI/ARB to sacubitril/valsartan was associated with an early and significant decrease in PAPs.

Sacubitril/Valsartan Reduces Fibrosis and Alleviates High-Salt Diet-Induced HFpEF in Rats

Previous studies have confirmed the clinical efficacy of sacubitril/valsartan (Sac/Val) for the treatment of heart failure with reduced ejection fraction (HFrEF). However, the role of Sac/Val in heart failure with preserved ejection fraction (HFpEF) remains unclear. Sac/Val is a combination therapeutic medicine comprising sacubitril and valsartan that acts as a first angiotensin receptor blocker and neprilysin inhibitor (angiotensin-receptor neprilysin inhibitor (ARNI)). Here, we investigated the role of Sac/Val in high-salt diet-induced HFpEF coupled with vascular injury as well as the underlying mechanism. Rats were fed with high-salt feed, followed by intragastric administration of Sac/Val (68 mg/kg; i.g.). The results of functional tests revealed that a high-salt diet caused pathological injuries in the heart and vascular endothelium, which were significantly reversed by treatment with Sac/Val. Moreover, Sac/Val significantly decreased the levels of fibrotic factors, including type I collagen and type Ⅲ collagen, thus, reducing the ratio of MMP2/TIMP2 while increasing Smad7 levels. Further investigation suggested that Sac/Val probably reversed the effects of high-salt diet-induced HFpEF by inhibiting the activation of the TGF-β1/Smad3 signaling pathway. Thus, treatment with Sac/Val effectively alleviated the symptoms of high-salt diet-induced HFpEF, probably by inhibiting fibrosis via the TGF-β1/Smad3 signaling pathway, supporting the therapeutic potential of Sac/Val for the treatment of HFpEF.

TaleNeprilysin and Neprilysin inhibition in chronic kidney disease

PURPOSE OF REVIEW

Chronic kidney disease (CKD) is associated with increased risk of progression to end-stage kidney disease and cardiovascular events. There is limited evidence that available treatments have beneficial effects on cardiorenal outcomes in all people with nondiabetic CKD. Neprilysin inhibition (NEPi) is a new therapeutic strategy with potential to improve outcomes for patients with CKD.

RECENT FINDINGS

NEPi enhances the activity of the natriuretic peptide system producing natriuresis, diuresis and inhibition of the renin-angiotensin system and sympathetic nervous system. Sacubitril/valsartan is the first Angiotensin receptor-neprilysin inhibitor (ARNI) to be produced and has been shown to substantially improve cardiovascular outcomes in heart failure and delay progression of kidney disease in this population. Although ARNIs have not shown similar effects on kidney function in the short-to-medium term in people with CKD, they are associated with substantial reductions in cardiac biomarkers and blood pressure in CKD.

SUMMARY

These data suggest that NEPi with an ARNI could benefit patients with CKD by reducing the risk of cardiovascular disease and have the possibility of retarding the progression of CKD (hence delaying the need for renal replacement therapy).

Sacubitril/Valsartan Inhibits Cardiomyocyte Hypertrophy in Angiotensin II-Induced Hypertensive Mice Independent of a Blood Pressure-Lowering Effect

Background

Hypertensive left ventricular hypertrophy is associated with the risk of heart failure, coronary heart disease and cerebrovascular disease. Although sacubitril/valsartan (SAC/VAL), a first-in-class angiotensin receptor neprilysin inhibitor, reduces the risks of death and hospitalization for patients with heart failure, its mechanism of action is not fully understood. We hypothesized that SAC/VAL is superior to other conventional drugs in reducing cardiac hypertrophy.

Methods

Male C57BL/6J mice were implanted with an osmotic pump containing angiotensin II (Ang II). After 7 days of Ang II infusion, mice were also treated with either SAC/VAL, valsartan, enalapril or vehicle alone each day for 2 weeks. Blood pressure measurement was done weekly, and echocardiography was performed before and 3 weeks after infusion of Ang II. Histological analyses were done using extracted heart to investigate cardiac hypertrophy and fibrosis.

Results

Ang II markedly elevated blood pressures in all of the treatment groups, and there were no differences in the degree of blood pressure reduction among the SAC/VAL-, valsartan- and enalapril-treated groups. Echocardiography showed that SAC/VAL significantly suppressed the increase in left ventricular (LV) wall thickness and tended to decrease LV mass. In a histological analysis, SAC/VAL inhibited Ang II-induced cardiomyocyte hypertrophy, and individual cardiomyocytes in the SAC/VAL group were smaller than those in the valsartan and enalapril groups. Although previous studies using animal models of heart failure have indicated that SAC/VAL attenuates cardiac fibrosis, we found no supporting evidence in this setting.

Conclusions

SAC/VAL, valsartan and enalapril all attenuated cardiomyocyte hypertrophy in a mouse model of Ang II-induced cardiac hypertrophy. Of note, SAC/VAL most strongly suppressed hypertrophy in spite of similar blood pressure-lowering effects as valsartan and enalapril. The present study suggests that SAC/VAL may have a beneficial effect on the early stage of hypertensive heart disease.

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.

Characterization of the inflammatory-metabolic phenotype of heart failure with a preserved ejection fraction: a hypothesis to explain influence of sex on the evolution and potential treatment of the disease

Accumulating evidence points to the existence of an inflammatory-metabolic phenotype of heart failure with a preserved ejection fraction (HFpEF), which is characterized by biomarkers of inflammation, an expanded epicardial adipose tissue mass, microvascular endothelial dysfunction, normal-to-mildly increased left ventricular volumes and systolic blood pressures, and possibly, altered activity of adipocyte-associated inflammatory mediators. A broad range of adipogenic metabolic and systemic inflammatory disorders - e.g. obesity, diabetes and metabolic syndrome as well as rheumatoid arthritis and psoriasis - can cause this phenotype, independent of the presence of large vessel coronary artery disease. Interestingly, when compared with men, women are both at greater risk of and may suffer greater cardiac consequences from these systemic inflammatory and metabolic disorders. Women show disproportionate increases in left ventricular filling pressures following increases in central blood volume and have greater arterial stiffness than men. Additionally, they are particularly predisposed to epicardial and intramyocardial fat expansion and imbalances in adipocyte-associated proinflammatory mediators. The hormonal interrelationships seen in inflammatory-metabolic phenotype may explain why mineralocorticoid receptor antagonists and neprilysin inhibitors may be more effective in women than in men with HFpEF. Recognition of the inflammatory-metabolic phenotype may improve an understanding of the pathogenesis of HFpEF and enhance the ability to design clinical trials of interventions in this heterogeneous syndrome.

Molecular, Cellular, and Clinical Evidence That Sodium-Glucose Cotransporter 2 Inhibitors Act as Neurohormonal Antagonists When Used for the Treatment of Chronic Heart Failure

Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce the risk of cardiovascular death and hospitalization for heart failure in patients with chronic heart failure. Initially, these drugs were believed to have a profile similar to diuretics or hemodynamically active drugs, but they do not rapidly reduce natriuretic peptides or cardiac filling pressures, and they exert little early benefit on symptoms, exercise tolerance, quality of life, or signs of congestion. Clinically, the profile of SGLT2 inhibitors resembles that of neurohormonal antagonists, whose benefits emerge gradually during sustained therapy. In experimental models, SGLT2 inhibitors produce a characteristic pattern of cellular effects, which includes amelioration of oxidative stress, mitigation of mitochondrial dysfunction, attenuation of proinflammatory pathways, and a reduction in myocardial fibrosis. These cellular effects are similar to those produced by angiotensin converting enzyme inhibitors, β-blockers, mineralocorticoid receptor antagonists, and neprilysin inhibitors. At a molecular level, SGLT2 inhibitors induce transcriptional reprogramming of cardiomyocytes that closely mimics that seen during nutrient deprivation. This shift in signaling activates the housekeeping pathway of autophagy, which clears the cytosol of dangerous cytosolic constituents that are responsible for cellular stress, thereby ameliorating the development of cardiomyopathy. Interestingly, similar changes in cellular signaling and autophagic flux have been seen with inhibitors of the renin-angiotensin system, β-blockers, mineralocorticoid receptor antagonists, and neprilysin inhibitors. The striking parallelism of these molecular, cellular, and clinical profiles supports the premise that SGLT2 inhibitors should be regarded as neurohormonal antagonists when prescribed for the treatment of heart failure with a reduced ejection fraction.

Effects of Low-Dose Sacubitril/Valsartan on Different Stages of Cardiac Hypertrophy in Salt-Loaded Hypertensive Rats

BACKGROUND

Sacubitril/valsartan was shown to attenuate the development of cardiac hypertrophy with enhanced blood pressure reduction compared with valsartan alone in animal models. We investigated whether a low-dose sacubitril/valsartan has blood pressure-independent effects on cardiac hypertrophy and pulmonary edema using a rat model of hypertension and obesity.

METHODS AND RESULTS

In plan 1, male SHR/NDmcr-cp rats fed normal or phase-increased high salt were treated with vehicle, 6-mg/kg sacubitril/valsartan or 3-mg/kg valsartan, for 6 months. In plan 2, after high-salt loading for 6 months, drugs were administered for 4 months. Antihypertensive effects of the 2 drugs were similar during all study periods. In plan 1 with normal salt, there were no differences between treatments in the left ventricle weight/body weight (BW), or lung weight/BW as an index of cardiac hypertrophy or pulmonary edema, respectively. These indexes were smaller in high-salt-fed rats with sacubitril/valsartan than vehicle. In plan 2, both indexes did not differ between vehicle and sacubitril/valsartan. Ventricle weight/BW was lower in valsartan than sacubitril/valsartan. In plan 2, gene markers of cardiac dysfunction were upregulated by sacubitril/valsartan compared with the other groups.

CONCLUSIONS

Low-dose sacubitril/valsartan may have different effects depending on the stage of cardiac hypertrophy in rats.

Dual Angiotensin Receptor and Neprilysin Inhibitor Ameliorates Portal Hypertension in Portal Hypertensive Rats

BACKGROUND

Portal hypertension is characterized by exaggerated activation of the renin-angiotensin-aldosterone axis. Natriuretic peptide system plays a counter-regulatory role, which is modulated by neprilysin. LCZ696 (sacubitril/valsartan) is a dual angiotensin receptor and neprilysin inhibitor. This study evaluated the effect of LCZ696 on portal hypertensive rats.

METHODS

Portal hypertension was induced by partial portal vein ligation (PVL) in rats. LCZ696, valsartan (angiotensin receptor blocker), or normal saline (control) was administered in PVL rats for 10 days. Then, hemodynamic and biochemistry data were obtained. The hepatic histology and protein expressions were surveyed. On the parallel groups, the portal-systemic shunting degrees were determined.

RESULTS

LCZ696 and valsartan reduced mean arterial pressure and systemic vascular resistance. LCZ696, but not valsartan, reduced portal pressure in portal hypertensive rats (control vs. valsartan vs. LCZ696: 15.4 ± 1.6 vs. 14.0 ± 2.3 vs. 12.0 ± 2.0 mmHg, control vs. LCZ696: P < 0.05). LCZ696 and valsartan improved liver biochemistry data and reduced intrahepatic Cluster of Differentiation 68 (CD68)-stained macrophages infiltration. Hepatic endothelin-1 (ET-1) protein expression was downregulated by LCZ696. The portal-systemic shunting was not affected by LCZ696 and valsartan.

CONCLUSION

LCZ696 and valsartan reduced mean arterial pressure through peripheral vasodilation. Furthermore, LCZ696 significantly reduced portal pressure in PVL rats via hepatic ET-1 downregulation.

Sacubitril/Valsartan Therapy Ameliorates Ventricular Tachyarrhythmia Inducibility in a Rabbit Myocardial Infarction Model

BACKGROUND

Coronary artery disease is the most common cause of heart failure (HF) in developed countries. The aim of this study was to elucidate the mechanisms of reduction of arrhythmias after sacubitril/valsartan (LCZ696) therapy in a myocardial infarction (MI)-HF rabbit model.

METHODS AND RESULTS

Chronic MI in rabbits with HF were divided into 3 groups: placebo control, valsartan 30 mg/day and LCZ696 60 mg/day. After 4 weeks of therapy, an electrophysiologic study and a dual voltage-calcium optical mapping study were performed. The LCZ696 group had significantly better left ventricular ejection fraction and lower ventricular tachyarrhythmia inducibility than the valsartan and placebo groups. The most common ventricular tachyarrhythmia pattern was 1 or 2 ectopic beats originating from the peri-infarct areas, followed by re-entrant beats surrounding phase singularity points. Compared to the valsartan and placebo groups, the LCZ696 group had significantly shorter action-potential duration, shorter intracellular calcium tau constant, faster conduction velocity, and shorter pacing cycle length to induce arrhythmogenic alternans. LCZ696 therapy reduced the phosphorylated calmodulin-dependent protein kinase II (CaMKII-p) expression.

CONCLUSIONS

In a rabbit model with chronic MI and HF, LCZ696 therapy ameliorated postinfarct heart function impairment and electrophysiologic remodeling and altered CaMKII-p expression, leading to reduced ventricular tachyarrhythmia inducibility.

Telmisartan and thiorphan combination treatment attenuates fibrosis and apoptosis in preventing diabetic cardiomyopathy

Aims

LCZ696, a first-generation dual angiotensin receptor-neprilysin inhibitor (ARNi), is effective in treating heart failure patients. However, the role of ARNis in treating diabetic cardiomyopathy is poorly understood. This study evaluates the efficacy of a novel combination of telmisartan [angiotensin receptor blocker (ARB)] and thiorphan [neprilysin inhibitor (NEPi)] in ameliorating diabetic cardiomyopathy while, at the same time, exploring the relevant underlying molecular mechanism(s).

Methods and results

Diabetes was induced by administration of streptozotocin (55 mg/kg, i.p.) in male Wistar rats. After 4 weeks, diabetic rats were subjected to either thiorphan (0.1 mg/kg/day, p.o.) or telmisartan (10 mg/kg/day, p.o.) monotherapy, or their combination, for a period of 4 weeks. Metabolic and morphometric alterations, failing ventricular functions, and diminished baroreflex indicated development of diabetic cardiac complications. Apart from morphometric alterations, all pathological consequences were prevented by telmisartan and thiorphan combination therapy. Diabetic rats exhibited significant modulation of the natriuretic peptide system, a key haemodynamic regulator; this was normalized by combination therapy. Histopathological studies showed augmented myocardial fibrosis, demonstrated by increased % PSR-positive area, with combination therapy giving the best improvement in these indices. More importantly, the combination of thiorphan and telmisartan was superior in attenuating inflammatory (NF-κB/MCP-1), profibrotic (TGF-β/Smad7) and apoptotic (PARP/Caspase-3) cascades compared to respective monotherapies when treating rats with diabetic cardiomyopathy. In addition, diabetic heart chromatin was in a state of active transcription, indicated by increased histone acetylation (H2AK5Ac, H2BK5Ac, H3K9Ac, and H4K8Ac) and histone acetyltransferase (PCAF and Ac-CBP) levels. Interestingly, combination treatment was sufficiently potent to normalize these alterations.

Conclusion

The protective effect of novel ARB and NEPi combination against diabetic cardiomyopathy can be attributed to inhibition of inflammatory, profibrotic, and apoptotic cascades. Moreover, reversal of histone acetylation assists its protective effect.

LCZ696, an Angiotensin Receptor-Neprilysin Inhibitor, Improves Cardiac Hypertrophy and Fibrosis and Cardiac Lymphatic Remodeling in Transverse Aortic Constriction Model Mice

Cardiac hypertrophy and ventricular remodeling following heart failure are important causes of high mortality in heart disease patients. The cardiac lymphatic system has been associated with limited research, but it plays an important role in the improvement of myocardial edema and the promotion of fluid balance. LCZ696 is a novel combination of angiotensin and neprilysin inhibitors. Here, we studied the role played by LCZ696 during transverse aortic constriction (TAC) induced cardiac hypertrophy and changes in the lymphatic system. Mice undergoing aortic coarctation were constructed to represent a cardiac hypertrophy model and then divided into random groups that either received treatment with LCZ696 (60 mg/kg/d) or no treatment. Cardiac ultrasonography was used to detect cardiac function, and hematoxylin and eosin (H&E) and Masson staining were used to detect myocardial hypertrophy and fibrosis. The proinflammatory factors interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-α (TNF-α) were detected in the blood and heart tissues of mice. The protein expression levels of lymphatic-specific markers, such as vascular endothelial growth factor C (VEGF-C), VEGF receptor 3 (VEGFR3), and lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1) were detected in mouse heart tissues. We also examined the colocalization of lymphatic vessels and macrophages by immunofluorescence. The results showed that LCZ696 significantly improved heart dysfunction, cardiac hypertrophy, and fibrosis and inhibited the expression of proinflammatory factors IL-6, IL-1β, and TNF-α in the circulating blood and heart tissues of mice. LCZ696 also decreased the protein expression levels of VEGF-C, VEGFR3, and LYVE-1 in mouse heart tissues, ameliorated the transport load of lymphatic vessels to macrophages, and improved the remodeling of the lymphatic system in the hypertrophic cardiomyopathy model induced by TAC.

Bioactive Signaling in Next-Generation Pharmacotherapies for Heart Failure: A Review

Importance

The standard pharmacotherapy for heart failure (HF), particularly HF with reduced ejection fraction (HFrEF), is primarily through the use of receptor antagonists, notably inhibition of the renin-angiotensin system by either angiotensin-converting enzyme inhibition or angiotensin II receptor blockade (ARB). However, the completed Prospective Comparison of ARNI With an ACE-Inhibitor to Determine Impact on Global Mortality and Morbidity in Heart Failure (PARADIGM-HF) trial identified that the use of a single molecule (sacubitril/valsartan), which is an ARB and the neutral endopeptidase inhibitor (NEPi) neprilysin, yielded improved clinical outcomes in HFrEF compared with angiotensin-converting enzyme inhibition alone.

Observations

This review examined specific bioactive signaling pathways that would be potentiated by NEPi and how these would affect key cardiovascular processes relevant to HFrEF. It also addressed potential additive/synergistic effects of ARB. A number of biological signaling pathways that may be potentiated by sacubitril/valsartan were identified, including some novel candidate molecules, which will act in a synergistic manner to favorably alter the natural history of HFrEF.

Conclusions and Relevance

This review identified that activation rather than inhibition of specific receptor pathways provided favorable cardiovascular effects that cannot be achieved by renin-angiotensin system inhibition alone. Thus, an entirely new avenue of translational and clinical research lies ahead in which HF pharmacotherapies will move beyond receptor antagonist strategies.

Interaction Between Sacubitril and Valsartan in Preventing Heart Failure Induced by Aortic Valve Insufficiency in Rats

BACKGROUND

Synergistic interactions between neprilysin inhibition (NEPi) with sacubitril and angiotensin receptor type1 blockade (ARB) with valsartan have been implicated in improvement of left ventricular (LV) contractility, relaxation, exercise tolerance, and fibrosis in preexisting heart failure (HF) induced by aortic valve insufficiency (AVI). It is not known whether this pharmacologic synergy can prevent cardiovascular pathology in a similar AVI model. Our aim was to investigate the pharmacology of sacubitril/valsartan in an experimental setting with therapy beginning immediately after creation of AVI.

METHODS

HF was induced through partial disruption of the aortic valve in rats. Therapy began 3 hours after valve disruption and lasted 8 weeks. Sacubitril/valsartan (68 mg/kg), valsartan (31 mg/kg), sacubitril (31 mg/kg), or vehicle were administered daily via oral gavage (N=8 in each group). Hemodynamic assessments were conducted using Millar technology, and an exercise tolerance test was conducted using a rodent treadmill.

RESULTS

Only sacubitril/valsartan increased total arterial compliance and ejection fraction (EF). Therapies with sacubitril/valsartan and valsartan similarly improved load-dependent (dP/dt_max) and load independent indices (Ees) of LV contractility, and exercise tolerance, whereas sacubitril did not. None of the therapies improved LV relaxation (dP/dt_min), whereas all reduced myocardial fibrosis.

CONCLUSIONS

1) The synergistic interaction between NEPi and ARB in early therapy with sacubitril/valsartan leads to increased total arterial compliance and EF. 2) Improvement in indices of LV contractility, and exercise tolerance with sacubitril/valsartan is likely because of ARB effect of valsartan. 3) All three therapies provided antifibrotic effects, suggesting both ARB and NEPi are capable of reducing myocardial fibrosis.

Clinical significance of serum magnesium levels in patients with heart failure with preserved ejection fraction

Although serum magnesium (Mg) levels are closely associated with the prognosis of heart failure (HF) patients, the clinical significance of sMg levels on the cardiovascular outcomes of HF with preserved ejection fraction (HFpEF) patients is not fully understood. This study was a retrospective, single-center, observational study. We enrolled 452 consecutive HFpEF patients admitted to Kumamoto University Hospital. We defined lower sMg as <2.0 mg/dl (=0.8 mmol/L) based on recent clinical evidence and compared their clinical characteristics and prognosis. There were no significant differences between groups in the use of all medications (loop diuretics, mineralocorticoid receptor antagonists, renin-angiotensin-aldosterone system inhibitors, calcium channel blockers, beta blockers, statins, and Mg preparations). The lower sMg group showed a significantly higher prevalence of diabetes mellitus (DM), uric acid levels, and BNP levels compared with the higher sMg group. Kaplan-Meier curve revealed a significantly higher probability of HF-related events in the lower sMg group compared with the higher sMg group (log-rank test, P = .012). Multivariate Cox-proportional-hazard analysis revealed that the lower sMg group had significantly and independently higher probabilities of HF-related events compared with the higher sMg group (hazard ratio = 2.37, 95% confidence intervals = 1.27-4.41, P = .007). We reclassified the risk of HF-related events after adding the lower sMg to the other prognostic factors (age, previous hospitalization for HF, DM, Ln-BNP); the continuous net reclassification improvement was 29.0% (P = .041). sMg levels might provide important prognostic information in regard to HFpEF.

Future pharmacological therapy in hypertension

PURPOSE OF REVIEW

Hypertension (HTN) is a widespread and growing disease, with medication intolerance and side-effect present among many. To address these obstacles novel pharmacotherapy is an active area of drug development. This review seeks to explore future drug therapy for HTN in the preclinical and clinical arenas.

RECENT FINDINGS

The future of pharmacological therapy in HTN consists of revisiting old pathways to find new targets and exploring wholly new approaches to provide additional avenues of treatment. In this review, we discuss the current status of the most recent drug therapy in HTN. New developments in well trod areas include novel mineralocorticoid antagonists, aldosterone synthase inhibitors, aminopeptidase-A inhibitors, natriuretic peptide receptor agonists, or the counter-regulatory angiotensin converting enzyme 2/angiotensin (Ang) (1-7)/Mas receptor axis. Neprilysin inhibitors popularized for heart failure may also still hold HTN potential. Finally, we examine unique systems in development never before used in HTN such as Na/H exchange inhibitors, vasoactive intestinal peptide agonists, and dopamine beta hydroxylase inhibitors.

SUMMARY

A concise review of future directions of HTN pharmacotherapy.

LCZ696 Therapy Reduces Ventricular Tachyarrhythmia Inducibility in a Myocardial Infarction-Induced Heart Failure Rat Model

Background

LCZ696 (valsartan/sacubitril) therapy significantly reduced mortality in patients with heart failure (HF). Although a clinical trial (PARADISE-MI Trial) has been ongoing to examine the effects of LCZ696 in myocardial infarction (MI) patients, the effects of LCZ696 on remodeling of cardiac electrophysiology in animal models remain largely unclear.

Methods

We performed coronary artery ligation to create MI in Sprague-Dawley rats. Echocardiography was performed one week after MI to confirm the development of HF with left ventricular ejection fraction ≤ 40%. MI rats were randomly assigned to receive medical therapy for 4 weeks: LCZ696, enalapril, or vehicle. The sham-operation rats received sham operation without MI creation. In vivo electrophysiological exams were performed under general anesthesia. Western blot analyses were conducted to quantify ion channel proteins.

Results

The HF-vehicle group did not show significant changes in LVEF. Both enalapril and LCZ696 therapy significantly improved LVEF. The HF-vehicle group had higher ventricular arrhythmia (VA) inducibility than the sham group. As compared with the HF-vehicle group, LCZ696 therapy significantly reduced VA inducibility, but enalapril therapy did not. Western blot analyses showed significant downregulation of Na_V1.5, ERG, KCNE1, and KCNE2 channel proteins in the HF vehicle group compared with the sham group. LCZ696 therapy upregulated protein expression of ERG, KCNE1, and KCNE2.

Conclusion

As compared with enalapril therapy, LCZ696 therapy led to improvement of LVEF, reduced VA inducibility, and upregulated expression of K⁺ channel proteins.

Strain-selective efficacy of sacubitril/valsartan on carotid fibrosis in response to injury in two inbred mouse strains

BACKGROUND AND PURPOSE

Sacubitril/valsartan (Sac/val) is more effective than valsartan in lowering BP and mortality in patients with heart failure. Here, we proposed that Sac/val treatment would be more effective in preventing pathological vascular remodelling in 129X1/SvJ (129X1), than in C57BL/6J (B6) inbred mice.

EXPERIMENTAL APPROACH

Sac/val (60 mg·kg^-1 ·day^-1 ) and valsartan (27 mg·kg^-1 ·day^-1 ) were given as prophylactic or therapeutic treatments, to 129X1 or B6 mice with carotid artery ligation for 14 days. Blood flow was measured by ultrasound. Ex vivo, carotid tissue was analysed with histological and morphometric techniques, together with RNA sequencing and gene ontology.

KEY RESULTS

Sac/val was more effective than valsartan in lowering BP in 129X1 compared with B6 mice. Liver expression of CYP2C9 and plasma cGMP levels were similar across treatments. A reduction in carotid thickening after prophylactic treatment with valsartan or Sac/val also resulted in significant arterial shrinkage in B6 mice. In 129X1 mice, Sac/val and prophylactic treatment with valsartan had no effect on carotid thickening but preserved carotid size. BP lowering significantly correlated with a decline in carotid stiffness (R²  = .37, P = .0096) in 129X1 but not in B6 mice. The gene expression signature associated with hyalurononglucosaminidase activity was down-regulated in injured arteries after both regimens of Sac/val only in 129X1 mice. Administration of Sac/val but not valsartan significantly reduced deposition of hyaluronic acid and carotid fibrosis in 129X1 mice.

CONCLUSION AND IMPLICATIONS

These results underscore the importance of the genetic background in the efficacy of the Sac/val on vascular fibrosis.

Effects of dual angiotensin type 1 receptor/neprilysin inhibition vs. angiotensin type 1 receptor inhibition on target organ injury in the stroke-prone spontaneously hypertensive rat

OBJECTIVES

The combination of AT1 blocker/neutroendopeptidase neprilysin inhibition (ARNi) represents an interesting approach to reduce cardiovascular risk in hypertension. We assessed the efficacy of ARNi, compared with angiotensin II type 1 receptor blockade alone, on blood pressure (BP) and on protection from target organ damage development in the stroke-prone spontaneously hypertensive rat (SHRSP).

METHODS

In high-salt fed SHRSP, we assessed plasma and tissue natriuretic peptides, urinary volume, BP and body weight over a short-term treatment (6 weeks) with either ARNi (sacubitril/valsartan 68 mg/kg per day) or valsartan (30 mg/kg per day), protection from stroke and renal damage (as documented by proteinuria) over 4 months of treatment with either sacubitril/valsartan or valsartan; the ability of either treatment to reduce progression of cerebrovascular and renal damage after 2 weeks of high-salt diet.

RESULTS

Higher levels of plasma and tissue atrial natriuretic peptide, of urinary cyclic guanosine 3'5'monophosphate and urine volumes, along with lower BP levels, were found upon sacubitril/valsartan as compared with valsartan over the short-term treatment. Sacubitril/valsartan caused a significant reduction of both BP and proteinuria levels and complete prevention of stroke over the long-term treatment. Once organ damage was established, a significant delay of its progression was observed with sacubitril/valsartan.

CONCLUSION

The dual angiotensin II type 1 receptor/neutroendopeptidase inhibition significantly increased atrial natriuretic peptide level and reduced BP. Complete prevention of stroke was achieved in this model. The ability of sacubitril/valsartan to reduce organ damage progression was superior to that of valsartan alone. ARNi may represent a highly effective therapeutic agent to protect from target organ damage development in hypertension.

ARNi: A Novel Approach to Counteract Cardiovascular Diseases

Cardiovascular diseases (CVDs) still represent the greatest burden on healthcare systems worldwide. Despite the enormous efforts over the last twenty years to limit the spread of cardiovascular risk factors, their prevalence is growing and control is still suboptimal. Therefore, the availability of new therapeutic tools that may interfere with different pathophysiological pathways to slow the establishment of clinical CVDs is important. Previously, the inhibition of neurohormonal systems, namely the renin–angiotensin–aldosterone system (RAAS) and the sympathetic nervous system, has proven to be useful in the treatment of many CVDs. Attempts have recently been made to target an additional hormonal system, that of the natriuretic peptides (NPs), which, when dysregulated, can also play a role in the development CVDs. Indeed, a new class of drug, the angiotensin receptor–neprilysin inhibitors (ARNi), has the ability to counteract the effects of angiotensin II as well as to increase the activity of NPs. ARNi have already been proven to be effective in the treatment of heart failure with reduced ejection fraction. New evidence has suggested that, in the next years, the field of ARNi application will widen to include other CVDs, such as heart failure, with preserved ejection fraction and hypertension.

AHU377+Valsartan (LCZ696) Modulates Renin-Angiotensin System (RAS) in the Cardiac of Female Spontaneously Hypertensive Rats Compared With Valsartan

BACKGROUND

Hypertension is a major cause of death and morbidity worldwide and is increasing in prevalence. The Renin-angiotensin system (RAS) is the most common mechanism involved in the pathophysiology of hypertension. Understanding the mechanism of the pathophysiologic processes will help direct potential therapeutic strategies to treat hypertension and improve cardiac function. Recently, a novel drug LCZ696 containing both an angiotensin receptor blocker valsartan and a neprilysin inhibitor (AHU377) has shown a promising effect on the treatment of hypertension. However, the effects of LCZ696 on the expression of main components of RAS, namely, angiotensin-converting enzyme (ACE), angiotensin-converting enzyme 2 (ACE2), angiotensin II type 1 receptor (AT1 R), angiotensin II type 2 receptor (AT2 R), and angiotensin (1-7) receptor/Mas receptor (MasR) remain unclear. The aim of the present study was to evaluate the effects of LCZ696 on the protective arms of RAS in the cardiac tissue when compared with valsartan under the equal inhibition of AT1 R. We hypothesized that the superior effects of LCZ696 may contribute to its greater effect on the RAS than valsartan.

MATERIALS AND METHODS

Sixteen-week-old female spontaneously hypertensive rats (SHRs) were used in this study. Wistar-Kyoto (WKY) rats were used as controls. All rats were randomly divided into LCZ696 (n = 10), valsartan (n = 10), SHR (n = 10), and WKY (n = 10) groups under a 12-hour dark and 12-hour light cycle and provided with regular chow diet and water. The tail-cuff method was performed to measure blood pressure. Cardiac function was assessed by echocardiography.

RESULTS

The blood pressure value was lower in LCZ696 than valsartan in SHR after 12 weeks of treatment. Further, LCZ696 inhibits the ACE and AT1 R protein expression in the cardiac of SHR and significantly upregulate the protective axis of RAS components, including ACE2, MasR, and AT2 R. Left ventricular AT2 R messenger RNA (mRNA) expression was higher in the LCZ696+SHR group compared with valsartan. In addition, real-time polymerase chain reaction analysis revealed that LCZ696 enhanced the mRNA expression of antihypertensive components AT2 R, ACE2, and MasR and decreased the expression of AT1 R. However, only AT2 R and ACE2 mRNA expressions have a statistical difference between the LCZ696 and valsartan groups. No difference was observed in the mRNA expression of ACE and MasR. The stronger positive signal of transforming growth factor β in the left ventricle was inhibited in each administrated group compared with SHR groups.

CONCLUSIONS

LCZ696 ameliorates the vasoconstrictor axis of the RAS AT1 R and stimulate the protective arm effectors, ACE2 and AT2 R, as well as reverses the compensatory upregulation of neuronal nitric oxide synthase and endothelial nitric oxide synthase in SHR. These findings suggest the mechanistic insight of the cardiac-protective and greater hypotensive effects of LCZ696.

Neprilysin Inhibitor-Angiotensin II Receptor Blocker Combination Therapy (Sacubitril/valsartan) Suppresses Atherosclerotic Plaque Formation and Inhibits Inflammation in Apolipoprotein E- Deficient Mice

We assessed the effects of the sacubitril/valsartan combination drug (LCZ696), in comparison to valsartan alone, on the progression of atherosclerotic plaque formation and inflammatory gene expression in apolipoprotein E- deficient mice (apoE^−/− mice). Seventy-two apoE^−/− mice were fed a western diet and a constrictive silastic tube was used to elicit carotid lesion formation. The animals were separated into a control group, a valsartan group or an LCZ696 group (n = 24 in each group). Plaques in the carotid artery were harvested 12 weeks later for histological examination. The levels of pro-inflammatory genes in the plasma and lesions were detected using real-time PCR and ELISA. Valsartan or LCZ696 treatment remarkably inhibited the expression of pro-inflammatory genes, including interleukin-6, matrix metalloproteinase-8 and monocyte chemotactic protein-1, in comparison with the control group. Meanwhile, both valsartan and LCZ696 suppressed the formation of atherosclerotic plaques by decreasing plaque lipid content and cross-sectional plaque area and increasing the content of plaque collagen and fibrous cap thickness. In particular, LCZ696 performed the best in suppressing atherosclerosis and inhibiting the level of pro-inflammatory genes. LCZ696 significantly ameliorated atherosclerosis and inflammation in apoE^−/− mice compared with valsartan.

Molecular Implications of Natriuretic Peptides in the Protection from Hypertension and Target Organ Damage Development

The pathogenesis of hypertension, as a multifactorial trait, is complex. High blood pressure levels, in turn, concur with the development of cardiovascular damage. Abnormalities of several neurohormonal mechanisms controlling blood pressure homeostasis and cardiovascular remodeling can contribute to these pathological conditions. The natriuretic peptide (NP) family (including ANP (atrial natriuretic peptide), BNP (brain natriuretic peptide), and CNP (C-type natriuretic peptide)), the NP receptors (NPRA, NPRB, and NPRC), and the related protease convertases (furin, corin, and PCSK6) constitute the NP system and represent relevant protective mechanisms toward the development of hypertension and associated conditions, such as atherosclerosis, stroke, myocardial infarction, heart failure, and renal injury. Initially, several experimental studies performed in different animal models demonstrated a key role of the NP system in the development of hypertension. Importantly, these studies provided relevant insights for a better comprehension of the pathogenesis of hypertension and related cardiovascular phenotypes in humans. Thus, investigation of the role of NPs in hypertension offers an excellent example in translational medicine. In this review article, we will summarize the most compelling evidence regarding the molecular mechanisms underlying the physiological and pathological impact of NPs on blood pressure regulation and on hypertension development. We will also discuss the protective effect of NPs toward the increased susceptibility to hypertensive target organ damage.

Efficacy and safety of sacubitril/valsartan compared with olmesartan in Asian patients with essential hypertension: A randomized, double-blind, 8-week study

This study assessed the efficacy and safety of angiotensin receptor neprilysin inhibitor sacubitril/valsartan vs olmesartan in Asian patients with mild-to-moderate hypertension. Patients (N = 1438; mean age, 57.7 years) with mild-to-moderate hypertension were randomized to receive once daily administration of sacubitril/valsartan 200 mg (n = 479), sacubitril/valsartan 400 mg (n = 473), or olmesartan 20 mg (n = 486) for 8 weeks. The primary endpoint was reduction in mean sitting systolic blood pressure (msSBP) from baseline with sacubitril/valsartan 200 mg vs olmesartan 20 mg at Week 8. Secondary endpoints included msSBP reduction with sacubitril/valsartan 400 mg, and reductions in clinic and ambulatory BP and pulse pressure (PP) vs olmesartan. In addition, changes in msBP from baseline in the Chinese subpopulation, elderly (≥65 years), and in patients with isolated systolic hypertension (ISH) were assessed. Sacubitril/valsartan 200 mg provided a significantly greater reduction in msSBP than olmesartan 20 mg at Week 8 (between-treatment difference: -2.33 mm Hg [95% confidence interval (CI) -4.00 to -0.66 mm Hg], P < 0.05 for non-inferiority and superiority). Greater reductions in msSBP were also observed with sacubitril/valsartan 400 mg vs olmesartan 20 mg (-3.52 [-5.19 to -1.84 mm Hg], P < 0.001 for superiority). Similarly, greater reductions in msBP were observed in the Chinese subpopulation, in elderly patients, and those with ISH. In addition, both doses of sacubitril/valsartan provided significantly greater reductions from baseline in nighttime mean ambulatory BP vs olmesartan. Treatment with sacubitril/valsartan 200 or 400 mg once daily is effective and provided superior BP reduction than olmesartan 20 mg in Asian patients with mild-to-moderate hypertension and is generally safe and well tolerated.

The renin-angiotensin system in cardiovascular autonomic control: recent developments and clinical implications

Complex and bidirectional interactions between the renin-angiotensin system (RAS) and autonomic nervous system have been well established for cardiovascular regulation under both physiological and pathophysiological conditions. Most research to date has focused on deleterious effects of components of the vasoconstrictor arm of the RAS on cardiovascular autonomic control, such as renin, angiotensin II, and aldosterone. The recent discovery of prorenin and the prorenin receptor have further increased our understanding of RAS interactions in autonomic brain regions. Therapies targeting these RAS components, such as angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers, are commonly used for treatment of hypertension and cardiovascular diseases, with blood pressure-lowering effects attributed in part to sympathetic inhibition and parasympathetic facilitation. In addition, a vasodilatory arm of the RAS has emerged that includes angiotensin-(1-7), ACE2, and alamandine, and promotes beneficial effects on blood pressure in part by reducing sympathetic activity and improving arterial baroreceptor reflex function in animal models. The role of the vasodilatory arm of the RAS in cardiovascular autonomic regulation in clinical populations, however, has yet to be determined. This review will summarize recent developments in autonomic mechanisms involved in the effects of the RAS on cardiovascular regulation, with a focus on newly discovered pathways and therapeutic targets for this hormone system.

Effect of LCZ696, a dual angiotensin receptor neprilysin inhibitor, on isoproterenol-induced cardiac hypertrophy, fibrosis, and hemodynamic change in rats

BACKGROUND

Recent clinical studies have shown that treatment with LCZ696, a complex containing the angiotensin receptor blocker valsartan and neprilysin inhibitor sacubitril, improves the prognosis of heart failure patients with a reduced ejection fraction. This study evaluated whether LCZ696 affects left ventricular hypertrophy, fibrosis, and hemodynamics in isoproterenol (ISO)-treated rats compared with valsartan alone.

METHODS

Male Wistar rats received subcutaneous saline (n = 10), subcutaneous ISO (2.4 mg/kg/day; n = 10), subcutaneous ISO + oral LCZ696 (60 mg/kg/day; n = 20) (ISO-LCZ), or subcutaneous ISO + oral valsartan (30 mg/kg/day; n = 20) (ISO-VAL) for 7 days.

RESULTS

LCZ696 and valsartan did not significantly reduce the increased heart weight/body weight ratio in rats treated with ISO. Echocardiography showed that the deceleration time shortened by ISO was restored by LCZ696 but not valsartan alone (p = 0.01 vs. the ISO group). Histological analysis showed that cardiac interstitial fibrosis increased by ISO was decreased significantly by LCZ696 but not valsartan alone (control: 0.10 ± 0.14%; ISO: 0.41 ± 0.32%; ISO-LCZ: 0.19 ± 0.23% [p < 0.01 vs. the ISO group]; ISO-VAL: 0.34 ± 0.23% [p = 0.34 vs. the ISO group]). Quantitative polymerase chain reaction showed that mRNA expression of Tgfb1, Col1a1, Ccl2, and Anp increased by ISO was significantly attenuated by LCZ696 but not valsartan alone (p < 0.05 vs. the ISO group).

CONCLUSIONS

LCZ696 improves cardiac fibrosis, but not hypertrophy, caused by continuous exposure to ISO in rats.

Combined Angiotensin Receptor-Neprilysin Inhibitors Improve Cardiac and Vascular Function Via Increased NO Bioavailability in Heart Failure

Background

There is a paucity of data about the mechanisms by which sacubitril/valsartan (also known as LCZ696) improves outcomes in patients with heart failure. Specifically, the effects of sacubitril/valsartan on vascular function and NO bioavailability have not been investigated. We hypothesized that sacubitril/valsartan therapy increases circulating NO levels and improves vascular function in the setting of heart failure.

Methods and Results

Male spontaneously hypertensive rats underwent myocardial ischemia/reperfusion surgery to induce heart failure and were followed for up to 12 weeks with serial echocardiography. Rats received sacubitril/valsartan (68 mg/kg), valsartan (31 mg/kg), or vehicle starting at 4 weeks after reperfusion. At 8 or 12 weeks of reperfusion, animals were euthanized and tissues were collected for ex vivo analyses of NO bioavailability, aortic vascular reactivity, myocardial and vascular histology, and cardiac molecular assays. Left ventricular structure and function were improved by both valsartan and sacubitril/valsartan compared with vehicle. Sacubitril/valsartan resulted in superior cardiovascular benefits, as evidenced by sustained improvements in left ventricular ejection fraction and end‐diastolic pressure. Ex vivo vascular function, as measured by aortic vasorelaxation responses to acetylcholine and sodium nitroprusside, was significantly improved by valsartan and sacubitril/valsartan, with more sustained improvements afforded by sacubitril/valsartan. Furthermore, myocardial NO bioavailability was significantly enhanced in animals receiving sacubitril/valsartan therapy.

Conclusions

Sacubitril/valsartan offers superior cardiovascular protection in heart failure and improves vascular function to a greater extent than valsartan alone. Sacubitril/valsartan‐mediated improvements in cardiac and vascular function are likely related to increases in NO bioavailability and explain, in part, the benefits beyond angiotensin receptor blockade.

Neprilysin inhibition and endothelin-1 elevation: Focus on the kidney

Increasing the degree of renin-angiotensin system (RAS) blockade by combining ≥2 RAS blockers marginally increases efficacy, but results in more side effects. Hence, interference with other systems is currently being investigated, like potentiation of natriuretic peptides with neprilysin inhibitors. However, the neprilysin inhibitor thiorphan was recently found to increase endothelin-1 when administered to TGR(mREN2)27 (Ren2) rats on top of RAS blockade. Here we investigated whether this effect is thiorphan-specific, by comparing the neprilysin inhibitors thiorphan and sacubitril, administered by osmotic minipumps at a low or high dose for 7 days, in Ren2 rats. Plasma and urinary levels of endothelin-1, atrial and brain natriuretic peptide (ANP, BNP) and their second messenger cyclic guanosine 3'5' monophosphate (cGMP) were monitored. No significant differences were found in the plasma concentrations of endothelin-1, cGMP, ANP and BNP after treatment, although plasma ANP tended to be higher in the high-dose thiorphan treatment group and the low- and high-dose sacubitril treatment groups, compared with vehicle. Urinary endothelin-1 increased in the low-dose thiorphan and high-dose sacubitril groups, compared with baseline, although significance was reached for the former only. Urinary cGMP rose significantly in the high-dose sacubitril treatment group compared with baseline. Both urinary endothelin-1 and cGMP were significantly higher in the high-dose sacubitril group compared with the low-dose sacubitril group. In conclusion, endothelin-1 upregulation occurs with both thiorphan and sacubitril, and is particularly apparent in neprilysin-rich organs like the kidney. High renal neprilysin levels most likely also explain why sacubitril increased cGMP in urine only.

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

LCZ696 (sacubitril/valsartan) can lower the risk of cardiovascular events in chronic heart failure. However, it is unclear whether LCZ696 can improve prognosis in patients with acute myocardial infarction (MI). The present study shows that LCZ696 can prevent cardiac rupture after MI, probably due to the suppression of pro-inflammatory cytokines, matrix metalloproteinase-9 activity and aldosterone production, and enhancement of natriuretic peptides in mice. These findings suggest the mechanistic insight of cardioprotective effects of LCZ696 against acute MI, resulting in the belief that LCZ696 might be useful clinically to improve survival after acute MI.

Angiotensin II Receptor-Neprilysin Inhibitor Sacubitril/Valsartan Improves Endothelial Dysfunction in Spontaneously Hypertensive Rats

BACKGROUND

We have previously demonstrated that antihypertensive treatment with renin-angiotensin system inhibitors restores the impaired endothelium-dependent hyperpolarization (EDH)-mediated responses in spontaneously hypertensive rats (SHRs). Herein, we investigated whether the angiotensin II receptor-neprilysin inhibitor sacubitril/valsartan (LCZ696) would improve reduced EDH-mediated responses and whether LCZ696 would exert additional effects on endothelium-dependent and endothelium-independent vasorelaxation compared with an angiotensin II type 1 receptor blocker alone during hypertension.

METHODS AND RESULTS

SHRs were treated for 3 months with either LCZ696 or valsartan, from the age of 8 to 11 months. Age-matched, untreated SHRs and Wistar-Kyoto rats served as controls. Membrane potentials and contractile responses were recorded from the isolated superior mesenteric arteries. Acetylcholine-induced, EDH-mediated responses were impaired in untreated SHRs compared with Wistar-Kyoto rats. EDH-mediated responses were similarly improved in the LCZ696- and valsartan-treated SHRs. No difference was observed in acetylcholine-induced, nitric oxide-mediated relaxations among the 4 groups. Endothelium-independent relaxations in response to a nitric oxide donor, sodium nitroprusside, and those to levcromakalim, an ATP-sensitive K+-channel opener, were similar among the 4 groups; however, the sensitivities to levcromakalim were significantly higher in both LCZ696- and valsartan-treated SHRs.

CONCLUSIONS

LCZ696 appears to be as effective as valsartan in improving the impaired EDH-mediated responses during hypertension. LCZ696 and valsartan exert similar beneficial effects on endothelium-independent relaxation via enhanced sensitivity of the ATP-sensitive K+ channel. However, the dual blockade of renin-angiotensin system and neutral endopeptidase with LCZ696 does not appear to provide additional benefit over valsartan alone on vasomotor function in mesenteric arteries of SHRs.