Combined Angiotensin Receptor Antagonism and Neprilysin Inhibition

Nonclassical Axis of the Renin-Angiotensin System and Neprilysin: Key Mediators That Underlie the Cardioprotective Effect of PPAR-Alpha Activation during Myocardial Ischemia in a Metabolic Syndrome Model

The activation of the renin-angiotensin system (RAS) participates in the development of metabolic syndrome (MetS) and in heart failure. PPAR-alpha activation by fenofibrate reverts some of the effects caused by these pathologies. Recently, nonclassical RAS components have been implicated in the pathogenesis of hypertension and myocardial dysfunction; however, their cardiac functions are still controversial. We evaluated if the nonclassical RAS signaling pathways, directed by angiotensin III and angiotensin-(1-7), are involved in the cardioprotective effect of fenofibrate during ischemia in MetS rats. Control (CT) and MetS rats were divided into the following groups: (a) sham, (b) vehicle-treated myocardial infarction (MI-V), and (c) fenofibrate-treated myocardial infarction (MI-F). Angiotensin III and angiotensin IV levels and insulin increased the aminopeptidase (IRAP) expression and decreased the angiotensin-converting enzyme 2 (ACE2) expression in the hearts from MetS rats. Ischemia activated the angiotensin-converting enzyme (ACE)/angiotensin II/angiotensin receptor 1 (AT1R) and angiotensin III/angiotensin IV/angiotensin receptor 4 (AT4R)-IRAP axes. Fenofibrate treatment prevented the damage due to ischemia in MetS rats by favoring the angiotensin-(1-7)/angiotensin receptor 2 (AT2R) axis and inhibiting the angiotensin III/angiotensin IV/AT4R-IRAP signaling pathway. Additionally, fenofibrate downregulated neprilysin expression and increased bradykinin production. These effects of PPAR-alpha activation were accompanied by a reduction in the size of the myocardial infarct and in the activity of serum creatine kinase. Thus, the regulation of the nonclassical axis of RAS forms part of a novel protective effect of fenofibrate in myocardial ischemia.

Sacubitril-valsartan cocrystal revisited: role of polymer excipients in the formulation

Objectives: This study investigated the impact of polymer excipients on a typical cocrystal for sacubitril (SAC) and valsartan (VAL), aiming to guide optional formulation design and maximize oral bioavailability.Methods: Poly vinyl pyrrolidone (PVP) and hydroxypropyl cellulose (HPC) and hydroxypropyl methylcellulose (HPMC) were selected. The dissolution/permeation system was used to predict both the kinetics of drug supersaturation and the simple permeation. The intermolecular interaction was analyzed by ¹H NMR spectroscopy and molecular dynamics simulation. Pharmacokinetic study was performed to assess the impact of polymer excipients in vivo.Results: Our study found that unappreciated excipients in the formulation, especially some polymers, might compete with the intermolecular hydrogen bonding among the cocrystals components and provide unexpected affinity, and thus leverage the therapeutic benefits. HPMC as a coating excipient used in the Entresto® tablet hampered the supersaturation of API, which led to the poor oral absorption of cocrystals. Conversely, PVP appeared to promote and maintain drug supersaturation, resulting in improved bioavailability of API.Conclusion: In conclusion, understanding the interplay between the cocrystal components and polymers is the key to optimizing the excipients to maximize the performance of cocrystal based oral drug formulation.

Sinergy between drugs and devices in the fight against sudden cardiac death and heart failure

The impact of sudden cardiac death (SCD) in heart failure (HF) patients is important and prevention of SCD is a reasonable and clinically justified endpoint if associated with a reduction in all-cause mortality. According to literature, in HF with reduced ejection fraction, only three classes of agents were found effective in reducing SCD and all-cause mortality: beta-blockers, mineralcorticoid receptor antagonists and, more recently, angiotensin-receptor neprilysin-inhibitors. In the PARADIGM trial that tested sacubitril/valsartan vs. enalapril, the 20% relative risk reduction in cardiovascular deaths obtained with sacubitril/valsartan was attributable to reductions in the incidence of both SCD and death due to HF worsening and this effect can be added to the known positive effect of implantable cardioverter-defibrillators in appropriately selected patients. In order to maximize the implementation of all the available treatments, patients with HF should be included in virtuous networks with a dialogue between all the physician involved, with commitment by all these physicians for appropriate decision-making on application of pharmacological and device treatments according to available evidence, as well as commitment for drug titration before and after device implant, taking advantage from remote monitoring, and with the safety of back up device therapy when indicated. There are potential synergistic effects of drug therapy, with all the therapies acting on neuro-hormonal and sympathetic activation, but specifically with sacubitril/valsartan, and device therapy, in particular cardiac resynchronization therapy, with added incremental benefits on positive cardiac remodelling, prevention of HF progression, and prevention of ventricular tachyarrhythmias.

Efficacy and safety of sacubitril-valsartan in heart failure: a meta-analysis of randomized controlled trials

Aims

Sacubitril‐valsartan has been shown to have superior effects over angiotensin‐converting enzyme inhibitors and angiotensin receptor blockers in patients with heart failure (HF) and hypertension. The efficacy and safety of sacubitril‐valsartan in patients with HF are controversial. We performed a meta‐analysis of randomized controlled trials to assess and compare the effect and adverse events of sacubitril‐valsartan, valsartan, and enalapril in patients with HF.

Methods and results

We conducted a systematic search using PubMed, Embase, the Cochrane Library, and ClinicalTrials.gov. Randomized controlled trials involving the use of sacubitril‐valsartan in patients with HF were included. We assessed the pooled odds ratio (OR) of all‐cause mortality, cardiovascular mortality, and hospitalization for HF in fixed‐effects models and the pooled risk ratio (RR) of symptomatic hypotension, worsening renal function, and hyperkalaemia in fixed‐effects models. Of the 315 identified records, six studies involving 14 959 patients were eligible for inclusion. Sacubitril‐valsartan reduced the endpoints of all‐cause mortality and cardiovascular mortality in patients with HF with reduced ejection fraction (HFrEF) in three trials with pooled ORs of 0.83 (P = 0.0006) and 0.78 (P < 0.0001), respectively. Regarding the composite outcome of hospitalization for HF in five trials, the pooled OR was 0.79 (P < 0.00001). Compared with enalapril or valsartan, sacubitril‐valsartan was associated with a high risk of symptomatic hypotension (RR 1.47, P < 0.00001), low risk of worsening renal function (RR 0.81, P = 0.005), and low rate of serious hyperkalaemia (≥6.0 mmol/L) (RR 0.76, P = 0.0007) in all six trials.

Conclusions

Compared with angiotensin‐converting enzyme inhibitors or angiotensin receptor blockers, sacubitril‐valsartan significantly decreased the risk of death from all causes or cardiovascular causes in HFrEF and hospitalization for HF in both patients with HFrEF and HF with preserved ejection fraction. Sacubitril‐valsartan reduced the risk of renal dysfunction and serious hyperkalaemia but was associated with more symptomatic hypotension.

Reverse electromechanical modelling of diastolic dysfunction in spontaneous hypertensive rat after sacubitril/valsartan therapy

Aims

Hypertension is a significant risk for the development of left ventricular hypertrophy, diastolic dysfunction, followed by heart failure and sudden cardiac death. While therapy with sacubitril/valsartan (SV) reduces the risk of sudden cardiac death in patients with heart failure and systolic dysfunction, the effect on those with diastolic dysfunction remains unclear. We hypothesized that, in the animal model of hypertensive heart disease, treatment with SV reduces the susceptibility to ventricular arrhythmia.

Methods and results

Young adult female spontaneous hypertensive rats (SHRs) were randomly separated into three groups, which were SHRs, SHRs treated with valsartan, and SHRs treated with SV. In addition, the age‐matched and weight‐matched Wistar Kyoto rats were considered as controls, and there were 12 rats in each group. In vivo ventricular tachyarrhythmia induction and in vitro optical mapping were used to measure the inducibility of ventricular arrhythmias and to characterize the dynamic properties of electrical propagation. The level of small‐conductance Ca²⁺‐activated potassium channel type 2 (KCNN2) was analysed in cardiac tissue. Compared with SHR with left ventricular hypertrophy, treatment with SV significantly improved cardiac geometry (relative wall thickness, 0.68 ± 0.11 vs. 0.76 ± 0.13, P < 0.05) and diastolic dysfunction (isovolumetric relaxation time, 59.4 ± 3.2 vs. 70.5 ± 4.2 ms, P < 0.05; deceleration time of mitral E wave, 46 ± 4.8 vs. 42 ± 3.8, P < 0.05). The incidence of induced ventricular arrhythmia was significantly reduced in SHR treated with SV compared with SHR (ventricular tachycardia, 1.14 ± 0.32 vs. 2.91 ± 0.5 episodes per 10 stimuli, P < 0.001; ventricular fibrillation, 1.72 ± 0.31 vs. 5.81 ± 0.42 episodes per 10 stimuli, P < 0.001). The prolonged action potential duration (APD) and increase of the maximum slope of APD restitution were observed in SHR, while the treatment of SV improved the arrhythmogeneity (APD, 37.12 ± 6.18 vs. 92.41 ± 10.71 ms at 250 ms pacing cycle length, P < 0.001; max slope 0.29 ± 0.01 vs. 1.48 ± 0.04, P < 0.001). These effects were strongly associated with down‐regulation of KCNN2 (0.38 ± 0.07 vs. 0.74 ± 0.12 ng/ml, P < 0.001). The treatment of SV also decreased the level of N‐terminal pro‐B‐type natriuretic peptide, cardiac bridging integrator‐1, and intramyocardial fibrosis of SHR.

Conclusions

In conclusion, synergistic blockade of the neprilysin and the renin–angiotensin system by SV in SHRs results in KCNN2‐associated electrical remodelling in ventricle, which stabilizes electrical dynamics and attenuates arrhythmogenesis.

Angioedema with sacubitril/valsartan: Trial-level meta-analysis of over 14,000 patients and real-world evidence to date

BACKGROUND

Sacubitril/valsartan reduces the risk of hospitalizations and death among patients with heart failure (HF) with reduced ejection fraction; its use is poised to increase worldwide. As bradykinin is a substrate of neprilysin, angioedema was a theoretical concern potentiated by neprilysin inhibition.

METHODS

We explored angioedema in clinical trials and real-world pharmacovigilance data. We conducted a trial-level random-effects meta-analysis of 5 RCTs studying the effects of sacubitril/valsartan in heart failure. FDA Adverse Event Reporting System (FAERS) provided real-world pharmacovigilance data in the US.

RESULTS

The 5 trials enrolled 14,841 patients with follow-up ranging from 2 to 27 months. The collective rate of angioedema in RCTs was 0.5% in sacubitril/valsartan arms vs. 0.3% in control arms (pooled odds ratio of 1.35; 95% confidence interval - 0.45 to 4.1; P = .59) with moderate heterogeneity (I² 55.2.%). These relative effects were driven by the larger PARADIGM-HF and PARAGON-HF experiences. FAERS pharmacovigilance data identified 426 angioedema cases over the last 5 years out of 40,559 adverse events reported related to sacubitril/valsartan.

CONCLUSIONS

Rates of angioedema with sacubitril/valsartan are reported to be low in RCTs and real-world clinical practice.

Lower Hospitalization and Healthcare Costs With Sacubitril/Valsartan Versus Angiotensin-Converting Enzyme Inhibitor or Angiotensin-Receptor Blocker in a Retrospective Analysis of Patients With Heart Failure

Background

Outcomes data among patients with heart failure (HF) with reduced ejection fraction treated with sacubitril/valsartan (SAC/VAL) are largely limited to clinical trial results. We compared hospitalization and healthcare costs among real‐world patients with HF with reduced ejection fraction treated with SAC/VAL versus angiotensin‐converting enzyme inhibitor or angiotensin‐receptor blocker (ACEI/ARB).

Methods and Results

Using retrospective administrative claims data, stable patients with HF with reduced ejection fraction treated with SAC/VAL or ACEI/ARB from October 2015 to June 2016 were identified. Postindex hospitalization and healthcare costs were assessed in propensity‐matched cohorts using robust variance estimation. Time to first hospitalization was modeled using unadjusted Kaplan–Meier estimates and multivariable models. Postindex all‐cause healthcare costs were modeled using an adjusted multivariable model. Among 279 patients per matched cohort, postindex hospitalization risk was lower for SAC/VAL compared with ACEI/ARB using Kaplan–Meier estimation and unadjusted Cox models. For HF hospitalization, the hazard ratio (95% CI) was 0.56 (0.33–0.94; P=0.030). Adjusted results were similar to unadjusted. Mean (SD) monthly healthcare costs were lower for SAC/VAL versus ACEI/ARB for all categories except pharmacy, with hospital costs being particularly disparate between cohorts: for HF hospitalization, $248 ($1588) for SAC/VAL versus $1122 ($7290) for ACEI/ARB. The adjusted risk of incurring increased all‐cause postindex costs was lower for SAC/VAL versus ACEI/ARB (cost ratio [95% CI] 0.74 [0.59–0.94]; P=0.013).

Conclusions

In clinical practice, patients with HF with reduced ejection fraction treated with SAC/VAL were less likely to be hospitalized than matched patients treated with ACEI/ARB. Despite higher pharmacy costs, SAC/VAL–treated patients incurred lower monthly medical and total healthcare costs.

Cardiovascular Outcomes with Sacubitril-Valsartan in Heart Failure: Emerging Clinical Data

One of the defining features of heart failure (HF) is neurohormonal activation. The renin-angiotensin-aldosterone-system (RAAS) and sympathetic nervous system (SNS) cause vasoconstriction and fluid retention and, in response, the secretion of natriuretic peptides (NPs) from volume and pressure-overloaded myocardium promotes vasodilation and diuresis. Inhibition of the RAAS with either angiotensin-converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB) has been the cornerstone of medical treatment for HF with a reduced ejection fraction (HFrEF) but, until recently, it was unclear how the beneficial effects of NPs may be augmented in patients with HF. Neprilysin, a metalloproteinase widely distributed throughout the body, plays a role in degrading the gross excess of circulating NPs in patients with HF. Early studies of neprilysin inhibition suggested possible physiological benefits. In 2014, the PARADIGM-HF trial found that sacubitril-valsartan, a combination of the ARB valsartan, and the neprilysin inhibitor sacubitril, was superior to enalapril in patients with HFrEF, reducing the relative risk of cardiovascular (CV) death or first hospitalisation with HF by 20%. Almost half of the patients with HF symptoms have a “preserved” ejection fraction (HFpEF); however, the PARAGON-HF study found that sacubitril-valsartan in patients with LVEF ≥45% had no effect on CV death or first and recurrent hospitalisations with HF compared to valsartan. Guidelines across the world have changed to include sacubitril-valsartan for patients with HFrEF yet, nearly 6 years after PARADIGM-HF, there is still uncertainty as to when and in whom sacubitril-valsartan should be started. Furthermore, there may yet be subsets of patients with HFpEF who might benefit from treatment with sacubitril-valsartan. This review will describe the mechanisms behind the outcome benefit of sacubitril-valsartan in patients with HFrEF and to consider its future role in the management of patients with HF.

Neuromodulation Therapy in Heart Failure: Combined Use of Drugs and Devices

Heart failure (HF) is the fastest-growing cardiovascular disease globally. The autonomic nervous system plays an important role in the regulation and homeostasis of cardiac function but, once there is HF, it takes on a detrimental role in cardiac function that makes it a rational target. In this review, we cover the remodeling of the autonomic nervous system in HF and the latest treatments available targeting it.

Impact of Sacubitril/Valsartan on Patient Outcomes in Heart Failure: Evidence to Date

With an estimated 6.2 million adults affected in the USA, heart failure remains a leading cause of morbidity, mortality, and health-care costs, despite the use of guideline-based medical therapies. The search for a more efficient therapy was rekindled when findings from the Prospective Comparison of Angiotensin Receptor–Neprilysin Inhibitor With Angiotensin-Converting Enzyme Inhibitor to Determine Impact on Global Mortality and Morbidity in Heart Failure (PARADIGM-HF) trial demonstrated evidence for cardiovascular and mortality benefit of sacubitril/valsartan, a dual angiotensin receptor blocker and neprilysin inhibitor (ARNI), over enalapril (an angiotensin-converting enzyme inhibitor) in patients with heart failure and reduced rjection fraction (HFrEF). Following the trial’s compelling results, recommendations for the use of sacubitril/valsartan as a replacement for an angiotensin-converting enzyme inhibitor and/or angiotensin receptor blocker were incorporated into the 2016 American College of Cardiology (ACC), the American Heart Association (AHA), and the Heart Failure Society of America recommended (HFSA) guidelines for the management of heart failure. This review aims to gain insight into the benefits as well as limitations associated with the use of sacubitril/valsartan in the treatment of heart failure (HF) through exploration of various subgroup analyses of the PARADIGM-HF trial, subsequent retrospective analyses, and randomized controlled trials that followed this landmark trial.

Sacubitrilat reduces pro-arrhythmogenic sarcoplasmic reticulum Ca2+ leak in human ventricular cardiomyocytes of patients with end-stage heart failure

Aims

Inhibition of neprilysin and angiotensin II receptor by sacubitril/valsartan (Val) (LCZ696) reduces mortality in heart failure (HF) patients compared with sole inhibition of renin–angiotensin system. Beneficial effects of increased natriuretic peptide levels upon neprilysin inhibition have been proposed, whereas direct effects of sacubitrilat (Sac) (LBQ657) on myocardial Ca²⁺ cycling remain elusive.

Methods and results

Confocal microscopy (Fluo‐4 AM) was used to investigate pro‐arrhythmogenic sarcoplasmic reticulum (SR) Ca²⁺ leak in freshly isolated murine and human ventricular cardiomyocytes (CMs) upon Sac (40 μmol/L)/Val (13 μmol/L) treatment. The concentrations of Sac and Val equalled plasma concentrations of LCZ696 treatment used in PARADIGM‐HF trial. Epifluorescence microscopy measurements (Fura‐2 AM) were performed to investigate effects on systolic Ca²⁺ release, SR Ca²⁺ load, and Ca²⁺‐transient kinetics in freshly isolated murine ventricular CMs. The impact of Sac on myocardial contractility was evaluated using in toto‐isolated, isometrically twitching ventricular trabeculae from human hearts with end‐stage HF. Under basal conditions, the combination of Sac/Val did not influence diastolic Ca²⁺‐spark frequency (CaSpF) nor pro‐arrhythmogenic SR Ca² leak in isolated murine ventricular CMs (n CMs/hearts = 80/7 vs. 100/7, P = 0.91/0.99). In contrast, Sac/Val treatment reduced CaSpF by 35 ± 9% and SR Ca²⁺ leak by 45 ± 9% in CMs put under catecholaminergic stress (isoproterenol 30 nmol/L, n = 81/7 vs. 62/7, P < 0.001 each). This could be attributed to Sac, as sole Sac treatment also reduced both parameters by similar degrees (reduction of CaSpF by 57 ± 7% and SR Ca²⁺ leak by 76 ± 5%; n = 101/4 vs. 108/4, P < 0.01 each), whereas sole Val treatment did not. Systolic Ca²⁺ release, SR Ca²⁺ load, and Ca²⁺‐transient kinetics including SERCA activity (k_SERCA) were not compromised by Sac in isolated murine CMs (n = 41/6 vs. 39/6). Importantly, the combination of Sac/Val and Sac alone also reduced diastolic CaSpF and SR Ca²⁺ leak (reduction by 74 ± 7%) in human left ventricular CMs from patients with end‐stage HF (n = 71/8 vs. 78/8, P < 0.05 each). Myocardial contractility of human ventricular trabeculae was not acutely affected by Sac treatment as the developed force remained unchanged over a time course of 30 min (n trabeculae/hearts = 3/3 vs. 4/3).

Conclusion

This study demonstrates that neprilysin inhibitor Sac directly improves Ca²⁺ homeostasis in human end‐stage HF by reducing pro‐arrhythmogenic SR Ca²⁺ leak without acutely affecting systolic Ca²⁺ release and inotropy. These effects might contribute to the mortality benefits observed in the PARADIGM‐HF trial.

Effects of sacubutril/valsartan on nutritional status in heart failure with reduced ejection fraction

BACKGROUND

Malnutrition commonly occurs in patients with heart failure with reduced ejection fraction (HFrEF). Sacubitril/valsartan, which is an AT1 neprilysin inhibitor, has been shown to reduce mortality and hospitalization in patients with HFrEF. However, its effects on nutritional status remain unclear.

METHODS

Sacubitril/valsartan was initiated in 164 symptomatic patients with HFrEF receiving an optimal medical treatment with angiotensin inhibition (mean age: 63 ± 20 years; 120 males, 60% ischemic cause). The New York Heart Association (NYHA) functional class and nutritional statuses of the patients were evaluated at the switching to AT1 neprilysin inhibitor and at the 6th-month follow-up of the maximum sacubitril/valsartan dose using the geriatric nutritional risk index (GNRI), controlling nutritional status (CONUT) score, prognostic nutritional index (PNI), and prealbumin.

RESULTS

After the sacubutril/valsartan treatment, a significant reduction in the number (%) of malnourished patients was observed according to CONUT (before 47% vs. after 7%, P < 0.001), GNRI (before 39% vs. after 19%, P < 0.001), PNI scores (before 36% vs. after 12%, P = 0.002), and prealbumin (before 41% vs. after 12%, P < 0.001). Also significant changes were observed at the baseline and follow-up in the mean scores of the three different nutritional indexes and prealbumin levels [CONUT: 2.68 ± 2.5, 1.02 ± 1.0 (P < 0.001); GNRI: 97.1 ± 9.7, 101.2 ± 5.9 (P < 0.001); PNI: 38.8 ± 4.8, 41.6 ± 3.7 (P < 0.001); prealbumin: 14.6 ± 6.9 mg/dl, 17.1 ± 5.2 mg/dl (P < 0.001)]. Overall, the patients exhibited a significant functional improvement following the initiation of sacubitril/valsartan: 23% of the patients improved by two NYHA classes, 48% improved by one NYHA class, and 39% remained stable.

CONCLUSION

In patients with HFrEF, the switch from angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker therapy to sacubitril/valsartan resulted in a significant improvement in both nutritional and functional statuses.

Potential Anti-Tumor Drug: Co-Crystal 5-Fluorouracil-nicotinamide

5-Fluorouracil-nicotinamide (5-FU-NCM), a co-crystal with a 2D layer structure formed by hydrogen bonds, was synthesized by solvent evaporation and liquid phase-assisted grinding at room temperature. Compared to 5-FU alone, the results of solubility, oil-water partition coefficient, anti-tumor effect in vivo and vitro, acute toxicity, and pharmacokinetic parameters indicate that the co-crystal is a potential anti-tumor drug.

Ventricular arrhythmias and ARNI: is it time to reappraise their management in the light of new evidence?

The remarkable scientific progress in the treatment of patients with heart failure (HF) and reduced ejection fraction (HFrEF) has more than halved the risk of sudden cardiac death (SCD) in this setting. However, SCD remains one of the major causes of death in this patient population. Beyond the acknowledged role of beta blockers and inhibitors of the renin-angiotensin-aldosterone system (RAAS), a new class of drugs, the angiotensin receptor neprilysin inhibitors (ARNI), proved to reduce the overall cardiovascular mortality and, more specifically, the risk of SCD in HFrEF patients. The mechanism by which ARNI may reduce the mortality connected with harmful ventricular arrhythmias is not utterly clear. A variety of direct and indirect mechanisms have been suggested, but a favorable left ventricular reverse remodeling seems to play a key role in this setting. Furthermore, the well-known protective effect of implantable cardioverter-defibrillator (ICD) has been debated in HFrEF patients with non-ischemic cardiomyopathy (NICM) arguing against the role of primary prevention ICD in this setting, particularly when ARNI therapy is considered. The purpose of this review was to provide insights into the SCD mechanisms involved in HFrEF patients together with the current role of electrical therapies and new drug agents in this setting. Graphical abstract.

Therapeutic approaches to diabetic cardiomyopathy: Targeting the antioxidant pathway

The global epidemic of cardiovascular disease continues unabated and remains the leading cause of death both in the US and worldwide. We hereby summarize the available therapies for diabetes and cardiovascular disease in diabetics. Clearly, the current approaches to diabetic heart disease often target the manifestations and certain mediators but not the specific pathways leading to myocardial injury, remodeling and dysfunction. Better understanding of the molecular events determining the evolution of diabetic cardiomyopathy will provide insight into the development of specific and targeted therapies. Recent studies largely increased our understanding of the role of enhanced inflammatory response, ROS production, as well as the contribution of Cyp-P450-epoxygenase-derived epoxyeicosatrienoic acid (EET), Peroxisome Proliferator-Activated Receptor Gamma Coactivator-1α (PGC-1α), Heme Oxygenase (HO)-1 and 20-HETE in pathophysiology and therapy of cardiovascular disease. PGC-1α increases production of the HO-1 which has a major role in protecting the heart against oxidative stress, microcirculation and mitochondrial dysfunction. This review describes the potential drugs and their downstream targets, PGC-1α and HO-1, as major loci for developing therapeutic approaches beside diet and lifestyle modification for the treatment and prevention of heart disease associated with obesity and diabetes.

Sacubitril/valsartan increases postprandial gastrin and cholecystokinin in plasma

AIMS

Neprilysin degrades natriuretic peptides in circulation and is also suggested to degrade the gut hormones gastrin and cholecystokinin. Neprilysin inhibition has become a therapeutic strategy and thus a regimen in need of further testing in terms of other hormonal axes besides natriuretic peptides. The aim of this study was to examine whether acute inhibition of neprilysin affects meal-induced responses in gastrin and cholecystokinin concentrations in healthy individuals.

METHODS AND RESULTS

Nine healthy young men were included in an open-labelled, randomized cross-over clinical trial. The participants received a standardized meal (25 g fat, 26 g protein, 42 g carbohydrate) on two separate days with or without a one-time dosage of sacubitril ((194 mg)/valsartan (206 mg)). Blood pressure, heart rate and blood samples were measured and collected during the experiment. Statistical differences between groups were assessed using area under the curve together with an ANOVA with a Bonferroni post hoc test. Sacubitril/valsartan increased the postprandial plasma concentrations of both gastrin and cholecystokinin (80% (AUC0-270 min, P = 0.004) and 60% (AUC0-270 min, P = 0.003), respectively) compared with the control meal. No significant hemodynamic effects were noted (blood pressure, AUC0-270 min, P = 0.86, heart rate, AUC0-270 min, P = 0.96).

CONCLUSION

Our study demonstrates that sacubitril/valsartan increases the postprandial plasma concentrations of gastrin and cholecystokinin in healthy individuals. The results thus suggest that neprilysin-mediated degradation of gastrin and cholecystokinin is physiologically relevant and may have a role in heart failure patients treated with sacubitril/valsartan.

Evaluation of new antihypertensive drugs designed in silico using Thermolysin as a target

The search for new therapies for the treatment of Arterial hypertension is a major concern in the scientific community. Here, we employ a computational biochemistry protocol to evaluate the performance of six compounds (Lig783, Lig1022, Lig1392, Lig2177, Lig3444 and Lig6199) to act as antihypertensive agents. This protocol consists of Docking experiments, efficiency calculations of ligands, molecular dynamics simulations, free energy, pharmacological and toxicological properties predictions (ADME-Tox) of the six ligands against Thermolysin. Our results show that the docked structures had an adequate orientation in the pocket of the Thermolysin enzymes, reproducing the X-ray crystal structure of Inhibitor-Thermolysin complexes in an acceptable way. The most promising candidates to act as antihypertensive agents among the series are Lig2177 and Lig3444. These compounds form the most stable ligand-Thermolysin complexes according to their binding free energy values obtained in the docking experiments as well as MM-GBSA decomposition analysis calculations. They present the lowest values of Ki, indicating that these ligands bind strongly to Thermolysin. Lig2177 was oriented in the pocket of Thermolysin in such a way that both OH of the dihydroxyl-amino groups to establish hydrogen bond interactions with Glu146 and Glu166. In the same way, Lig3444 interacts with Asp150, Glu143 and Tyr157. Additionally, Lig2177 and Lig3444 fulfill all the requirements established by Lipinski Veber and Pfizer 3/75 rules, indicating that these compounds could be safe compounds to be used as antihypertensive agents. We are confident that our computational biochemistry protocol can be used to evaluate and predict the behavior of a broad range of compounds designed in silicoagainst a protein target.

How ACE inhibitors transformed the renin-angiotensin system

The renin-angiotensin system (RAS) now underlies the successful treatment of almost 50% of the patients in cardiovascular medicine, with serious possibilities of extension to diabetes, Alzheimer's disease and cancer. This clinical transformation started just over 50 years ago, with the unexpected identification of a bradykinin-potentiating peptide from snake venom, as a potent inhibitor of ACE which led to the development of the first synthetic inhibitor, captopril, followed by the angiotensin receptor blockers. This article analyses the transformation of the RAS into its different stages, from academic experiments to clinical use and back to the laboratory, identifying the critical events involved, both clinical and scientific. The analysis also assesses the contributions of chance, coincidence, and conviction that were crucial in this transformation. Although questions remain, the transformation of the RAS over the past five decades provides a success story for medicine, for pharmacology, and, most significantly, for patients.

Switching from ramipril to sacubitril/valsartan favorably alters electrocardiographic indices of ventricular repolarization in heart failure with reduced ejection fraction

Background: Angiotensin receptor neprilysin inhibitor (ARNI, sacubitril/valsartan) reduces sudden death in heart failure with reduced ejection fraction (HFrEF). Corrected QT (QTc), T-wave peak to T-wave end interval (Tp-e) and Tp-e/QTc are electrocardiographic indices of ventricular repolarization heterogeneity. We aimed to assess the effects of switching from ramipril to ARNI on electrocardiographic indices of ventricular repolarization.Methods: A total of 48 patients with HFrEF (mean age: 63.3 ± 11.7 years; 36 males, 77.1% ischaemic etiology) were enrolled. All patients had New York Heart Association functional class II-III, left ventricular ejection fraction ≤35% and previously switched from ramipril to ARNI treatment. The standard 12-lead electrocardiograms on ramipril treatment and 1 month after ARNI treatment were analysed; heart rate, QTc, Tp-e and Tp-e/QTc were calculated. Minnesota Living with Heart Failure Questionnaire (MLWHFQ) scores and N-terminal pro-BNP (NT-proBNP) values were recorded.Results: QTc (415.2 ± 19.7 ms vs. 408.5 ± 20.8 ms, p = 0.022), Tp-e (100.7 ± 13.8 ms vs. 92.9 ± 12.1 ms, p < 0.001), Tp-e/QTc (0.242 ± 0.028 vs. 0.227 ± 0.029, p = 0.003) and heart rate (73.2 ± 4.7 bpm vs. 71.1 ± 4.9 bpm, p = 0.027) were reduced after ARNI. ARNI switch associated with improvement in MLWHFQ scores (32.4 ± 7.1 ms vs. 22.6 ± 7.0 ms, p < 0.001) and reduction of NT-proBNP (2457 ± 1879 pg/ml to 1377 ± 874 pg/ml, p < 0.001). Pearson's correlation analysis revealed moderate correlations of MLWHFQ score with Tp-e (r = 0.543, p = 0.001) and Tp-e/QTc (r = 0.556, p = 0.001).Conclusions: Switching from ramipril to ARNI favourably alters QTc, Tp-e and Tp-e/QTc in HFREF. ARNI reduces symptoms of HFREF assessed by MLWHFQ and lowers NT-proBNP levels. Reduction in Tp-e and Tp-e/QTc correlate with clinical improvement in patients with HFrEF.

The impact of discontinuation of sacubitril-valsartan and shifting to angiotensin-converting enzyme inhibitor or angiotensin receptor blocker in patients with heart failure with reduced ejection fraction

OBJECTIVE

Many trials confirmed the role of sacubitril-valsartan in the treatment of patients with heart failure with reduced ejection fraction (HFrEF). However, there is no sufficient data to register the effect of compulsory discontinuation of sacubitril-valsartan, either because of finan-cial shortage or adverse effects, and shifting to the standard therapy, including angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB).

METHODS

The patients with HFrEF (LVEF ≤35%) were included in the study. They received treatment with sacubitril-valsartan as a replacement for an ACEI or ARB. The patients were divided into two groups: the compliant group (n=111). The non-compliant group (n=82), whose members discontinued sacubitril-valsartan after ≥5 months but <6 months since their enrollment in the study.

RESULTS

Initially, 199 patients with HFrEF were included in the study. All the patients were started treatment with sacubitril-valsartan in addition to the evidence-based standard therapy of heart failure. Six patients were excluded at the first follow-up visit (at 6 months). The remaining 193 patients showed initial improvement of the New York Heart Association (NYHA) class, the end-diastolic volume (EDV), and the left ventricular ejection fraction (LVEF). Five patients were excluded at the 12 months' follow-up visit. The other 188 patients were divided into two groups: Group I (n=108) patients were compliant on sacubitril-valsartan for 12 months; Group II (n=80) patients were compliant on sacubitril-valsartan for ≥5 months, but stopped it at <6 months, and were shifted to ACEI or evidence-based ARB. Group II (n=80) patients showed worsening of their NYHA class, compared to the 6 months' follow-up visit (p=0.001). LVEF and EDV were also shown to be worsened in these patients when we compared them to the values of the 6 months' follow-up appointment with p=0.001 for both parameters.

CONCLUSION

The discontinuation of sacubitril-valsartan in patients with HFrEF leads to deterioration of the LVEF as well as worsening of the functional class. The decline in LVEF and NYHA functional class occurs despite being compliant with the optimal conventional therapy with ACEI or evidence-based ARB.

Electrophilic ring fluorination of 3,5-disubstituted pyrazoles: application to the formal synthesis of a neprilysin inhibitor key intermediate

The access to a new family of unusual 4-fluorinated pyrazoles bearing acetal moities at the 3- or 5-position has been achieved by electrophilic fluorination using Selectfluor® with yields up to 67%.

Treatment of Pulmonary Hypertension With Angiotensin II Receptor Blocker and Neprilysin Inhibitor Sacubitril/Valsartan

BACKGROUND

Angiotensin II has been implicated in maladaptive right ventricular (RV) hypertrophy and fibrosis associated with pulmonary hypertension (PH). Natriuretic peptides decrease RV afterload by promoting pulmonary vasodilation and inhibiting vascular remodeling but are degraded by neprilysin. We hypothesized that angiotensin receptor blocker and neprilysin inhibitor, sacubitril/valsartan (Sac/Val, LCZ696), will attenuate PH and improve RV function by targeting both pulmonary vascular and RV remodeling.

METHODS

PH was induced in rats using the SU5416/hypoxia model (Su/Hx), followed by 6-week treatment with placebo, Sac/Val, or Val alone. There were 4 groups: CON-normoxic animals with placebo (n=18); PH-Su/Hx rats+placebo (n=34); PH+Sac/Val (N=24); and PH+Val (n=16).

RESULTS

In animals with PH, treatment with Sac/Val but not Val resulted in significant reduction in RV pressure (mm Hg: PH: 62±4, PH+Sac/Val: 46±5), hypertrophy (RV/LV+S: PH: 0.74±0.06, PH+Sac/Val: 0.46±0.06), collagen content (µg/50 µg protein: PH: 8.2±0.3, PH+Sac/Val: 6.4±0.4), pressures and improvement in RVs (mm/s: PH: 31.2±1.8, PH+Sac/Val: 43.1±3.6) compared with placebo. This was associated with reduced pulmonary vascular wall thickness, increased lung levels of ANP (atrial natriuretic peptide), BNP (brain-type natriuretic peptide), and cGMP, and decreased plasma endothelin-1 compared with PH alone. Also, PH+Sac/Val animals had altered expression of PKC isozymes in RV tissue compared with PH alone.

CONCLUSIONS

Sac/Val reduces pulmonary pressures, vascular remodeling, as well as RV hypertrophy in a rat model of PH and may be appropriate for treatment of pulmonary hypertension and RV dysfunction.

Emerging Drug Classes and Their Potential Use in Hypertension

Despite the availability of multiple antihypertensive drugs targeting the different pathways implicated in its pathophysiology, hypertension remains poorly controlled worldwide, and its prevalence is increasing because of the aging of the population and the obesity epidemic. Although nonadherence to treatment contributes to uncontrolled hypertension, it is likely that not all the pathophysiological mechanisms are neutralized by the various classes of antihypertensive treatment currently available, and, the counter-regulatory mechanisms triggered by these treatments may decrease their blood pressure–lowering effect. The development of new antihypertensive drugs acting on new targets, with different modes of action, therefore, remains essential, to improve blood pressure control and reduce the residual burden of cardiovascular risks further. However, the difficulties encountered in the conception, development, costs, and delivery to the market of new classes of antihypertensive agents highlights the hurdles that must be overcome to release and to evaluate their long-term safety and efficacy for hypertension only, especially because of the market pressure of cheap generic drugs. New chemical entities with blood pressure–lowering efficacy are thus being developed more for heart failure or diabetic kidney disease, 2 diseases pathophysiologically associated with hypertension. These include dual angiotensin II receptor-neprilysin inhibitors, soluble guanylate cyclase stimulators, nonsteroidal dihydropyridine-based mineralocorticoid receptor antagonists, as well as sodium-glucose cotransporter 2 inhibitors. However, centrally acting aminopeptidase A inhibitors and endothelin receptor antagonists have a dedicated program of development for hypertension. All these emergent drug classes and their potential use in hypertension are reviewed here.

Impact of Sacubitril/Valsartan on the Long-Term Incidence of Ventricular Arrhythmias in Chronic Heart Failure Patients

Background: Sacubitril/valsartan decreased the risk of sudden cardiac death (SCD) in patients suffering from heart failure with reduced ejection fraction (HFrEF). However, long-term data are sparse. Objective: The aim of the present study was to compare the incidence of life-threatening arrhythmias consisting of ventricular tachycardia and/or ventricular fibrillation before and after initiation of sacubitril/valsartan treatment. Methods: Out of 12,000 patients with HFrEF from 2016–2018, 148 patients were newly prescribed sacubitril/valsartan, but the long-term data of only 127 patients were available and included in this study. Results: Patients with an average age of 66.8 ± 12.1 had a median left ventricular ejection fraction (LVEF) of 25% (interquartile range (IQR) 5.00–45.00) and 30% (IQR 10.00–55.00, p < 0.0005) before and after sacubitril/valsartan treatment, respectively. Systolic blood pressure decreased from 127.93 ± 22.01 to 118.36 ± 20.55 mmHg (p = 0.0035) at 6 months of follow-up. However, in 59 patients with a long-term outcome of 12 months, ventricular arrhythmias persistently increased (ventricular fibrillation from 27.6 to 29.3%, ventricular tachycardia (VT) from 12% to 13.8%, and nonsustained VT from 26.6 to 33.3%). Conclusions: Sacubitril/valsartan does not reduce the risk of ventricular tachyarrhythmias in chronic HFrEF patients over 12 months of follow-up.

Multifunctional Role of Chymase in Acute and Chronic Tissue Injury and Remodeling

Chymase is the most efficient Ang II (angiotensin II)-forming enzyme in the human body and has been implicated in a wide variety of human diseases that also implicate its many other protease actions. Largely thought to be the product of mast cells, the identification of other cellular sources including cardiac fibroblasts and vascular endothelial cells demonstrates a more widely dispersed production and distribution system in various tissues. Furthermore, newly emerging evidence for its intracellular presence in cardiomyocytes and smooth muscle cells opens an entirely new compartment of chymase-mediated actions that were previously thought to be limited to the extracellular space. This review illustrates how these multiple chymase-mediated mechanisms of action can explain the residual risk in clinical trials of cardiovascular disease using conventional renin-angiotensin system blockade.

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.

Adoption of Sacubitril/Valsartan for the Management of Patients With Heart Failure

BACKGROUND

The US Food and Drug Administration approved the use of sacubitril/valsartan in patients with heart failure with reduced ejection fraction in July 2015. We aimed to assess the adoption and prescription drug costs of sacubitril/valsartan in its first 18 months after Food and Drug Administration approval.

METHODS AND RESULTS

Using a large US insurance database, we identified privately insured and Medicare Advantage beneficiaries who filled a first prescription for sacubitril/valsartan between July 1, 2015, and December 31, 2016. We compared them to patients treated with an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker. Outcomes included adoption, prescription drug costs, and 180-day adherence, defined as a proportion of days covered ≥80%. A total of 2244 patients initiated sacubitril/valsartan. Although the number of users increased over time, the proportion of heart failure with reduced ejection fraction patients taking sacubitril/valsartan remained low (<3%). Patients prescribed sacubitril/valsartan were younger, more often male, with less comorbidity than those taking an angiotensin-converting enzyme inhibitor/angiotensin receptor blocker. Although a majority of prescription costs were covered by the health plan (mean, $328.37; median, $362.44 per 30-day prescription), out-of-pocket costs were still high (mean, $71.16; median, $40.27). By comparison, median out-of-pocket costs were $2 to $3 for lisinopril, losartan, carvedilol, and spironolactone. Overall, 59.1% of patients were adherent to sacubitril/valsartan. Refill patterns suggested that nearly half of nonadherent patients discontinued sacubitril/valsartan within 180 days of starting.

CONCLUSIONS

Adoption of sacubitril/valsartan after Food and Drug Administration approval has been slow and may be associated with the high cost.

BNP and NT-proBNP as Diagnostic Biomarkers for Cardiac Dysfunction in Both Clinical and Forensic Medicine

Currently, brain natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) are widely used as diagnostic biomarkers for heart failure (HF) and cardiac dysfunction in clinical medicine. They are also used as postmortem biomarkers reflecting cardiac function of the deceased before death in forensic medicine. Several previous studies have reviewed BNP and NT-proBNP in clinical medicine, however, few articles have reviewed their application in forensic medicine. The present article reviews the biological features, the research and application status, and the future research prospects of BNP and NT-proBNP in both clinical medicine and forensic medicine, thereby providing valuable assistance for clinicians and forensic pathologists.

The combination of a neprilysin inhibitor (sacubitril) and angiotensin-II receptor blocker (valsartan) attenuates glomerular and tubular injury in the Zucker Obese rat

OBJECTIVE

Diabetic nephropathy (DN) is characterized by glomerular and tubulointerstitial injury, proteinuria and remodeling. Here we examined whether the combination of an inhibitor of neprilysin (sacubitril), a natriuretic peptide-degrading enzyme, and an angiotensin II type 1 receptor blocker (valsartan), suppresses renal injury in a pre-clinical model of early DN more effectively than valsartan monotherapy.

METHODS

Sixty-four male Zucker Obese rats (ZO) at 16 weeks of age were distributed into 4 different groups: Group 1: saline control (ZOC); Group 2: sacubitril/valsartan (sac/val) (68 mg kg^-1 day^-1; ZOSV); and Group 3: valsartan (val) (31 mg kg^-1 day^-1; ZOV). Group 4 received hydralazine, an anti-hypertensive drug (30 mg kg^-1 day^-1, ZOH). Six Zucker Lean (ZL) rats received saline (Group 5) and served as lean controls (ZLC). Drugs were administered daily for 10 weeks by oral gavage.

RESULTS

Mean arterial pressure (MAP) increased in ZOC (+ 28%), but not in ZOSV (- 4.2%), ZOV (- 3.9%) or ZOH (- 3.7%), during the 10 week-study period. ZOC were mildly hyperglycemic, hyperinsulinemic and hypercholesterolemic. ZOC exhibited proteinuria, hyperfiltration, elevated renal resistivity index (RRI), glomerular mesangial expansion and podocyte foot process flattening and effacement, reduced nephrin and podocin expression, tubulointerstitial and periarterial fibrosis, increased NOX2, NOX4 and AT₁R expression, glomerular and tubular nitroso-oxidative stress, with associated increases in urinary markers of tubular injury. None of the drugs reduced fasting glucose or HbA1c. Hypercholesterolemia was reduced in ZOSV (- 43%) and ZOV (- 34%) (p < 0.05), but not in ZOH (- 13%) (ZOSV > ZOV > ZOH). Proteinuria was ameliorated in ZOSV (- 47%; p < 0.05) and ZOV (- 30%; p > 0.05), but was exacerbated in ZOH (+ 28%; p > 0.05) (ZOSV > ZOV > ZOH). Compared to ZOC, hyperfiltration was improved in ZOSV (p < 0.05 vs ZOC), but not in ZOV or ZOH. None of the drugs improved RRI. Mesangial expansion was reduced by all 3 treatments (ZOV > ZOSV > ZOH). Importantly, sac/val was more effective in improving podocyte and tubular mitochondrial ultrastructure than val or hydralazine (ZOSV > ZOV > ZOH) and this was associated with increases in nephrin and podocin gene expression in ZOSV (p < 0.05), but not ZOV or ZOH. Periarterial and tubulointerstitial fibrosis and nitroso-oxidative stress were reduced in all 3 treatment groups to a similar extent. Of the eight urinary proximal tubule cell injury markers examined, five were elevated in ZOC (p < 0.05). Clusterin and KIM-1 were reduced in ZOSV (p < 0.05), clusterin alone was reduced in ZOV and no markers were reduced in ZOH (ZOSV > ZOV > ZOH).

CONCLUSIONS

Compared to val monotherapy, sac/val was more effective in reducing proteinuria, renal ultrastructure and tubular injury in a clinically relevant animal model of early DN. More importantly, these renoprotective effects were independent of improvements in blood pressure, glycemia and nitroso-oxidative stress. These novel findings warrant future clinical investigations designed to test whether sac/val may offer renoprotection in the setting of DN.

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.

Sacubitril/valsartan: evaluation of safety and efficacy as an antihypertensive treatment

Hypertension (HTN) is a common disease state associated with extensive morbidity and mortality worldwide. It is often difficult for patients with HTN to achieve and maintain a goal blood pressure (BP), despite there being many effective treatment options available. Sacubitril/valsartan is a first-in-class angiotensin receptor neprilysin inhibitor (ARNI) that has garnered approval by the US Food and Drug Administration and the European Medicines Agency as a first-line treatment for heart failure with reduced ejection fraction. During clinical trials for heart failure as well as in independent trials for HTN, sacubitril/valsartan has demonstrated safety and efficacy when it comes to BP lowering, making it a promising antihypertensive agent. Most trials of sacubitril/valsartan were 8 to 12 weeks in length and demonstrated a clinically relevant BP lowering that was frequently more significant than its comparators. While more data are needed to confirm its role as an antihypertensive agent, the data available are promising and it is anticipated that sacubitril/valsartan will gain an indication of HTN.

Sacubitril/valsartan in cardiovascular disease: evidence to date and place in therapy

Cardiovascular (CV) disease is a major cause of morbidity and mortality in the developing and the developed world. Mortality from CV disease had plateaued in the recent years raising concerning alarms about the sustained efficacy of available preventive and treatment options. Heart failure (HF) is among the major contributors to the CV-related health care burden, a persisting concern despite the use of clinically proven guideline-directed therapies. A requirement for more efficient medical therapies coupled with recent advances in bio-innovation led to the creation of sacubitril/valsartan, an angiotensin receptor-neprilysin inhibitor (ARNI), which demonstrated substantial CV benefit when compared with the standard of care, enalapril, in patients with HF and reduced ejection fraction. Further investigations of this novel combination ARNI at the tissue level shed light into the anti-remodeling and cardioprotective effects of sacubitril/valsartan, while clinical studies in the phenotypes of HF with preserved ejection fraction, hypertension and subsets, coronary outcomes, postmyocardial infarction, and renal disease suggested that this combination could be beneficial across a wide spectrum of CV disease. Sacubitril/valsartan is a much-needed therapeutic advance in the avenue of CV disease.

Plasma renin activity in patients with heart failure and reduced ejection fraction on optimal medical therapy

Background:

Renin-angiotensin-aldosterone system (RAAS) activation in heart failure with reduced ejection fraction (HFREF) is detrimental through promotion of ventricular remodeling and salt and water retention.

Aims:

The aims of this article are to describe RAAS activity in distinct HFREF populations and to assess its prognostic impact.

Methods:

Venous blood samples were prospectively obtained in 76 healthy volunteers, 72 patients hospitalized for acute decompensated HFREF, and 78 ambulatory chronic HFREF patients without clinical signs of congestion. Sequential measurements were performed in patients with acute decompensated HFREF.

Results:

Plasma renin activity (PRA) was significantly higher in ambulatory chronic HFREF (7.6 ng/ml/h (2.2; 18.1)) compared to patients with acute decompensated HFREF (1.5 ng/ml/h (0.8; 5.7)) or healthy volunteers (1.4 ng/ml/h (0.6; 2.3)) (all p < 0.05). PRA was significantly associated with arterial blood pressure and renin-angiotensin system blocker dose. A progressive rise in PRA (+4 ng/ml/h (0.4; 10.9); p < 0.001) was observed in acute decompensated HFREF patients after three consecutive days of decongestive treatment. Only in acute HFREF were PRA levels associated with increased cardiovascular mortality or HF readmissions (p = 0.035).

Conclusion:

PRA is significantly elevated in ambulatory chronic HFREF patients but is not associated with worse outcome. In contrast, in acute HFREF patients, PRA is associated with cardiovascular mortality or HF readmissions.

Pharmacodynamic interaction between intravenous nitroglycerin and oral sacubitril/valsartan (LCZ696) in healthy subjects

PURPOSE

Sacubitril/valsartan (LCZ696) and nitroglycerin share the second messenger cGMP and lower blood pressure. Given the potential for co-administration of both drugs in patients with heart failure, this study was designed to investigate the potential for a pharmacodynamic drug interaction affecting blood pressure.

METHODS

In this double-blind, placebo-controlled, randomised, crossover study, 40 healthy subjects received sacubitril/valsartan 200 mg bid (97/103 mg bid) or placebo for 5 days. Two hours after the morning dose of sacubitril/valsartan or placebo on day 5, subjects received intravenous nitroglycerin infusion at increasing doses up to 40 μg/min or placebo. Serial measurements of blood pressure (BP), heart rate, biomarkers and sacubitril/valsartan pharmacokinetics were conducted.

RESULTS

Administration of nitroglycerin alone led to a dose- and time-dependent decrease in supine systolic BP (SBP) and diastolic BP (DBP) which was similar when nitroglycerin was co-administered with sacubitril/valsartan. At the highest dose of nitroglycerin, the mean (95% CI) decrease from baseline of SBP/DBP was 19.54 (- 21.99, - 17.09)/12.38 (- 13.85, - 10.92) mmHg for nitroglycerin alone compared to 22.63 (- 25.06, - 20.21)/12.94 (- 14.38, - 11.49) mmHg when co-administered with sacubitril/valsartan. Co-administration of sacubitril/valsartan and nitroglycerin did not result in further plasma cGMP increase compared to sacubitril/valsartan alone. The co-administration of nitroglycerin and sacubitril/valsartan was safe and well tolerated and did not impact the pharmacokinetics of sacubitril/valsartan.

CONCLUSIONS

The results from this study demonstrate no pharmacodynamic drug interaction between nitroglycerin and sacubitril/valsartan in healthy subjects, suggesting that no change of dose selection and escalation recommendations or clinical monitoring during nitroglycerin administration is required.

The reverse remodeling response to sacubitril/valsartan therapy in heart failure with reduced ejection fraction

BACKGROUND

Major classes of medical therapy for heart failure with reduced ejection fraction (HFrEF) induce reverse remodeling. The revere remodeling response to sacubitril/valsartan remains unstudied.

METHODS

We performed a single-center, prospective assessor-blinded study to determine the reverse remodeling response of sacubitril/valsartan therapy in HFrEF patients with a class I indication (New York heart Association [NYHA]-class II-IV, Left ventricular ejection fraction [LVEF] < 35%, optimal dose with Renin-Angiotensin-System-Blocker [RAS-blocker]). Doses of sacubitril/valsartan were optimized to individual tolerance. Echocardiographic images were assessed offline by 2 investigators blinded to both the clinical data and timing of echocardiograms.

RESULTS

One-hundred-twenty-five HFrEF patients (66 ± 10 years) were prospectively included. The amount of RAS-blocker before and after switch to sacubitril/valsartan was similar(P = .290), indicating individual optimal dosing of sacubitril/valsartan. Over a median(IQR) follow-up of 118(77-160) days after initiation of sacubitril/valsartan, LVEF improved (29.6 ± 6% vs 34.8 ± 6%; P < .001) and Left ventricular end-systolic (LVESV) and end-diastolic volume (LVEDV) decreased (LVESV; 147 ± 57 mL vs 129 ± 55 mL; P < .001 and LVEDV; 206 ± 71 mL vs197 ± 72 mL; P = .027). Volumetric remodeling was associated with a reduction in the degree of mitral regurgitation (1.59 ± 1.0 vs 1.11 ± 0.8; P < .001; [scale from 0-4]). Metrics of diastolic function improved; including a drop in the E/A-wave ratio (1.75 ± 1.13 vs 1.38 ± 0.88; P = .002) and diastolic filling time (% of cycle length) prolonged (48 ± 9% vs 52 ± 1%; P = .005). The percent of patients with a restrictive mitral filling pattern dropped from 47% to 23% (P = .004). A dose-dependent effect was noted for changes in LVEF (P < .001) and LVESV (P = .031), with higher doses of sacubitril/valsartan leading to more reverse remodeling.

CONCLUSION

Switching therapy in eligible HFrEF patients from a RAS-blocker to sacubitril/valsartan induces beneficial reverse remodeling of both metrics of systolic as diastolic function.

MicroRNA-143 modulates the expression of Natriuretic Peptide Receptor 3 in cardiac cells

Natriuretic Peptide Receptor 3 (NPR3), the clearance receptor for extracellular bio-active natriuretic peptides (NPs), plays important roles in the homeostasis of body fluid volume and vascular tone. Using luciferase reporter and antagomir-based silencing assays, we demonstrated that the expression of NPR3 could be modulated by microRNA-143 (miR-143-3p), a microRNA species with up-regulated circulating concentrations in clinical heart failure. The regulatory effect of miR-143 on NPR3 expression was further evidenced by the reciprocal relationship between miR-143 and NPR3 levels observed in hypoxia-treated human cardiac cells and in left ventricular tissue from rats undergoing experimental myocardial infarction. Further analysis indicated elevation of miR-143 in response to hypoxic challenge reflects transcriptional activation of the miR-143 host gene (MIR143HG). This was corroborated by demonstration of the induction of host gene promoter activity upon hypoxic challenge. Moreover, miR-143 was shown to enhance its own expression by increasing MIR143HG promoter activity, as well as targeting the expressions of NPPA, NPPC, NR3C2, and CRHR2 in cardiac cells. Taken together, these findings suggest that the elevation of miR-143 upon hypoxic insult may be part of a microRNA-based feed forward loop that results in fine tuning the levels of NPs and neurohormonal receptors in cardiac cell lineages.

Heart Failure With Preserved Ejection Fraction in Diabetes: Mechanisms and Management

Diabetes mellitus (DM) is a major cause of heart failure in the Western world, either secondary to coronary artery disease or from a distinct entity known as "diabetic cardiomyopathy." Furthermore, heart failure with preserved ejection fraction (HFpEF) is emerging as a significant clinical problem for patients with DM. Current clinical data suggest that between 30% and 40% of patients with HFpEF suffer from DM. The typical structural phenotype of the HFpEF heart consists of endothelial dysfunction, increased interstitial and perivascular fibrosis, cardiomyocyte stiffness, and hypertrophy along with advanced glycation end products deposition. There is a myriad of mechanisms that result in the phenotypical HFpEF heart including impaired cardiac metabolism and substrate utilization, altered insulin signalling leading to protein kinase C activation, advanced glycated end products deposition, prosclerotic cytokine activation (eg, transforming growth factor-β activation), along with impaired nitric oxide production from the endothelium. Moreover, recent investigations have focused on the role of endothelial-myocyte interactions. Despite intense research, current therapeutic strategies have had little effect on improving morbidity and mortality in patients with DM and HFpEF. Possible explanations for this include a limited understanding of the role that direct cell-cell communication or indirect cell-cell paracrine signalling plays in the pathogenesis of DM and HFpEF. Additionally, integrins remain another important mediator of signals from the extracellular matrix to cells within the failing heart and might play a significant role in cell-cell cross-talk. In this review we discuss the characteristics and mechanisms of DM and HFpEF to stimulate potential future research for patients with this common, and morbid condition.

Prolonged First-Dose Hypotension Induced by Sacubitril/Valsartan

Entresto was recommanded by major guidelines as the frontline therapy for heart failure with reduced ejection fraction since its clinical benefit was proved by the PARADIGM-HF trial. Angiotensin converting enzyme inhibitors are the cornerstone of the treatment of HF. Varying incidences of first-dose hypotension have been reported and recognized as a potential limiting factor for prescribing. According to previous reports, the onset of hypotension mostly occur 3-5 hours after the first dose. However, the pattern of entresto-related hypotension has not been reported. We present a case of HF, who had delay onset (about 8 to 18 hours) and prolonged (3 to 6 days) first-dose hypotension. Further investigation is required to illustrate this phenomenon.

Effects of angiotensin-neprilysin inhibition compared to angiotensin inhibition on ventricular arrhythmias in reduced ejection fraction patients under continuous remote monitoring of implantable defibrillator devices

BACKGROUND

Angiotensin-neprilysin inhibition compared to angiotensin inhibition decreased sudden cardiac death in patients with reduced ejection fraction heart failure (rEFHF). The precise mechanism remains unclear.

OBJECTIVE

The purpose of this study was to explore the effect of angiotensin-neprilysin inhibition on ventricular arrhythmias compared to angiotensin inhibition in rEFHF patients with an implantable cardioverter-defibrillator (ICD) and remote monitoring.

METHODS

We prospectively included 120 patients with ICD and (1) New York Heart Association functional class ≥II; (2) left ventricular ejection fraction ≤40%; and (3) remote monitoring. For 9 months, patients received 100% angiotensin inhibition with angiotensin-converting enzyme inhibitor (ACEi) or angiotensin receptor blocker (ARB), beta-blockers, and mineraloid antagonist. Subsequently, ACEi or ARB was changed to sacubitril-valsartan in all patients, who were followed for 9 months. Appropriate shocks, nonsustained ventricular tachycardia (NSVT), premature ventricular contraction (PVC) burden, and biventricular pacing percentage were analyzed.

RESULTS

Patients were an average age of 69 ± 8 years and had mean left ventricular ejection fraction of 30.4% ± 4% (82% ischemic). Use of beta-blockers (98%), mineraloid antagonist (97%) and antiarrhythmic drugs was similar before and after sacubitril-valsartan. Sacubitril-valsartan significantly decreased NSVT episodes (5.4 ± 0.5 vs 15 ± 1.7 in angiotensin inhibition; P <.002), sustained ventricular tachycardia, and appropriate ICD shocks (0.8% vs 6.7% in angiotensin inhibition; P <.02). PVCs per hour decreased after sacubitril-valsartan (33 ± 12 vs 78 ± 15 in angiotensin inhibition; P <.0003) and was associated with increased biventricular pacing percentage (from 95% ± 6% to 98.8% ± 1.3%; P <.02).

CONCLUSION

Angiotensin-neprilysin inhibition decreased ventricular arrhythmias and appropriate ICD shocks in rEFHF patients under home monitoring compared to angiotensin inhibition.

Angiotensin-Neprilysin Inhibition as a Paradigm for All?

Composite angiotensin receptor-neprilysin inhibition (ARNi) represents a novel pharmacologic strategy for treatment of heart failure with reduced ejection fraction (HFrEF). In the PARADIGM-HF (Prospective comparison of ARNi with ACEi to Determine Impact on Global Mortality and Morbidity in Heart Failure) trial of 8399 subjects with HFrEF, treatment with the ARNi LCZ696 (sacubitril/valsartan) was associated with statistically important reductions in cardiovascular death, all-cause mortality, and the composite of cardiovascular death or heart failure hospitalization in comparison with enalapril. These data have supported the US and European regulatory approval of sacubitril/valsartan and guideline-based recommendations for its use in the treatment of selected patients with HFrEF. In this review, we discuss the evidence supporting use of ARNi in preference to angiotensin-converting enzyme-inhibitors or angiotensin receptor blockers in patients with HFrEF and identify a strategy for selection of appropriate patients for transition to ARNi in clinical practice.