Comparison of candesartan, enalapril, and their combination in congestive heart failure: randomized evaluation of strategies for left ventricular dysfunction (RESOLVD) pilot study. The RESOLVD Pilot Study Investigators

Sequencing Quadruple Therapy for Heart Failure with Reduced Ejection Fraction: Does It Really Matter?

The conventional sequence of guideline-directed medical therapy (GDMT) initiation in heart failure with reduced ejection fraction (HFrEF) assumes that the effectiveness and tolerability of GDMT agents mirror their order of discovery, which is not true. In this review, the authors discuss flexible GDMT sequencing that should be permitted in special populations, such as patients with bradycardia, chronic kidney disease, or atrial fibrillation. Moreover, the initiation of certain GDMT medications may enable tolerance of other GDMT medications. Most importantly, the achievement of partial doses of all four pillars of GDMT is better than achievement of target dosing of only a couple.

Looking for the ideal medication for heart failure with reduced ejection fraction: a narrative review

The main goals of the pharmacological treatment of Heart failure with reduced ejection fraction (HFrEF) are the reduction of mortality and the prevention of hospitalizations. However, other outcomes such as improvements in cardiac remodeling and clinical status, functional capacity and quality of life, should be taken into account. Also, given the significant inter-individual and intra-individual variability of HF, and the fact that patients usually present with comorbidities, an appropriate treatment for HFrEF should exert a clinical benefit in most patient profiles irrespective of their characteristics or the presence of comorbidities, while providing organ protection beyond the cardiovascular system. The aim of this narrative review is to determine which are the proven effects of the guideline-directed treatments for HFrEF on five key clinical outcomes: cardiovascular mortality and hospitalization due to HF, sudden death, reverse cardiac remodeling, renal protection and evidence in hospitalized patients. Publications that fulfilled the pre-established selection criteria were selected and reviewed. Renin-angiotensin system (RAS) inhibitors, namely angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin II receptor blockers (ARBs) or angiotensin receptor-neprilysin inhibitors (ARNI), beta-blockers (BB), mineralocorticoid receptor antagonists (MRA), sodium-glucose co-transporter 2 inhibitors (SGLT2i) show a benefit in terms of mortality and hospitalization rates. ARNI, BB, and MRA have demonstrated a significant positive effect on the incidence of sudden death. ARB, ARNI, BB and SGLT2i have been associated with clear benefits in reverse cardiac remodeling. Additionally, there is consistent evidence of renal protection from ARB, ARNI, and SGLT2i in renal protection and of benefits for hospitalized patients from ARNI and SGLT2i. In conclusion, the combination of drugs that gather most beneficial effects in HFrEF, beyond cardiovascular mortality and hospitalization, would be ideally pursued.

First-in-human study evaluating safety, pharmacokinetics, and pharmacodynamics of lorundrostat, a novel and highly selective aldosterone synthase inhibitor

Dysregulation of the mineralocorticoid hormone aldosterone is an increasingly prevalent cause of hypertension. Aldosterone synthase (CYP11B2) shares 93% homology to 11β-hydroxylase (CYP11B1), which produces cortisol. Lorundrostat, a highly selective inhibitor of CYP11B2, is a potential safe and effective treatment for aldosterone-dependent, uncontrolled hypertension, including treatment-resistant hypertension. Lorundrostat showed highly selective inhibition of CYP11B2 in vitro, with 374-fold selectivity for CYP11B2 vs. CYP11B1. A first-in-human study of single ascending doses ranging from 5 to 800 mg and multiple ascending doses ranging from 40 to 360 mg once daily was conducted in healthy participants. After single- and multiple-dose administration, lorundrostat plasma levels peaked 1-3 h after administration with a t1/2 of 10-12 h. Plasma aldosterone decreased up to 40% with single 100-mg to 200-mg doses and up to 70% with single 400 to 800-mg doses. Plasma aldosterone returned to baseline within 16 h after single 100-mg doses and multiple once-daily 120-mg doses. Lorundrostat demonstrated a favorable safety profile in healthy participants. Dose- and exposure-dependent inhibition of renal tubular sodium reabsorption was observed across a clinically relevant dose range with no suppression of basal or cosyntropin-stimulated cortisol production and only a modest increase in mean serum potassium.

Discontinuation of afterload-reducing drugs decreases left ventricular outflow tract obstruction in hypertrophic obstructive cardiomyopathy

Background

Hypertrophic cardiomyopathy (HCM), the most common genetic heart disease, is classified into hypertrophic non-obstructive and hypertrophic obstructive cardiomyopathy (HOCM). Patients with HOCM and coexisting heart failure or arterial hypertension are often prescribed afterload-reducing drugs. Although recommended in current guidelines, data on the direct effect of discontinuing afterload-reducing medication are scarce. This study aims to demonstrate the benefit of discontinuing afterload-reducing medication in HOCM patients.

Methods

This monocentric retrospective analysis included 24 patients with HOCM with afterload-reducing medication, including angiotensin-converting enzyme inhibitors, angiotensin-1 receptor blocker and dihydropyridine-calcium channel blocker, at their first outpatient visit. Effects of discontinuing this medication on LVOTO were examined compared to patients with persistent use despite medical advice.

Results

16 patients discontinued their afterload-reducing drugs, resulting in a significant decrease in median LVOT gradient from 86.5 [60.5-109.3] mmHg to 61.5 [28.3-97.50] mmHg (p = 0.0004). In 6 patients, beta-blocker therapy was initiated simultaneously, or the dose was increased. Regardless, LVOT gradient reduction was also significant in the remaining 10 patients (p = 0.001). The gradient was not changed significantly in the 8 patients continuing their afterload-reducing medication.

Conclusions

Discontinuation of afterload-reducing drugs significantly decreases LVOTO. Our study underscores the significance of abstaining from afterload-reducing drugs in HOCM patients, particularly in patients with concomitant hypertension or heart failure. According to recently published European guidelines, HOCM patients should preferably be treated with beta-blockers or non-dihydropyridine-calcium channel blockers.

Development and evolution of nuclear cardiology and cardiac PET in Canada

Gated radionuclide angiography and myocardial perfusion imaging were developed in the United States and Europe in the 1970's and soon adopted in Canadian centers. Much of the early development of nuclear cardiology in Canada was in Toronto, Ontario and was quickly followed by new programs across the country. Clinical research in Canada contributed to the further development of nuclear cardiology and cardiac PET. The Canadian Nuclear Cardiology Society (CNCS) was formed in 1995 and became the Canadian Society of Cardiovascular Nuclear and CT Imaging (CNCT) in 2014. The CNCS had a major role in education and advocacy for cardiovascular nuclear medicine testing. The CNCS established the Dr Robert Burns Lecture and CNCT named the Canadian Society of Cardiovascular Nuclear and CT Imaging Annual Achievement Award for Dr Michael Freeman in memoriam of these two outstanding Canadian leaders in nuclear cardiology. The future of nuclear cardiology in Canada is exciting with the expanding use of SPECT imaging to include Tc-99m-pyrophosphate for diagnosis of transthyretin cardiac amyloidosis and the ongoing introduction of cardiac PET imaging.

Mineralocorticoid receptor overactivation: targeting systemic impact with non-steroidal mineralocorticoid receptor antagonists

The overactivation of the mineralocorticoid receptor (MR) promotes pathophysiological processes related to multiple physiological systems, including the heart, vasculature, adipose tissue and kidneys. The inhibition of the MR with classical MR antagonists (MRA) has successfully improved outcomes most evidently in heart failure. However, real and perceived risk of side effects and limited tolerability associated with classical MRA have represented barriers to implementing MRA in settings where they have been already proven efficacious (heart failure with reduced ejection fraction) and studying their potential role in settings where they might be beneficial but where risk of safety events is perceived to be higher (renal disease). Novel non-steroidal MRA have distinct properties that might translate into favourable clinical effects and better safety profiles as compared with MRA currently used in clinical practice. Randomised trials have shown benefits of non-steroidal MRA in a range of clinical contexts, including diabetic kidney disease, hypertension and heart failure. This review provides an overview of the literature on the systemic impact of MR overactivation across organ systems. Moreover, we summarise the evidence from preclinical studies and clinical trials that have set the stage for a potential new paradigm of MR antagonism.

Candesartan Attenuates Vasculitis in a Mouse Model of Kawasaki Disease Induced by Candida albicans Water-Soluble Fraction

BACKGROUND

The standard treatment for Kawasaki disease is immunoglobulin therapy, but the high frequency of coronary sequelae in immunoglobulin-refractory cases indicates a need for further improvement in treatment.

METHODS

Kawasaki disease-like vasculitis was induced in 5-week-old DBA/2 mice by intraperitoneal administration of 0.5 mg Candida albicans water-soluble fraction (CAWS) daily for 5 days followed by daily administration of candesartan, an angiotensin receptor blocker. The vasculitis suppression effect was confirmed histologically and serologically in mice sacrificed at 28 days after the start of candesartan.

RESULTS

The area of inflammatory cell infiltration at the aortic root was 2.4±1.4% in the Control group, 18.1±1.9% in the CAWS group, and 7.1±2.3%, 5.8±1.4%, 7.6±2.4%, and 7.9±5.0% in the CAWS+candesartan 0.125-mg/kg, 0.25-mg/kg, 0.5-mg/kg, and 1.0-mg/kg groups, respectively (p=0.0200, p=0.0122, p=0.0122, and p=0.0200 vs. CAWS, respectively). The low-dose candesartan group also showed significantly reduced inflammatory cell infiltration. A similar trend was confirmed by immunostaining of macrophages and TGFβ receptors. Measurement of the inflammatory cytokines IL-1β, IL-6, and TNF-α confirmed the anti-vasculitis effect of candesartan.

CONCLUSIONS

Candesartan inhibited vasculitis even at clinical doses used in children, making it a strong future candidate as an additional treatment for immunoglobulin-refractory Kawasaki disease.

Sequencing Quadruple Therapy for Heart Failure with Reduced Ejection Fraction: Does It Really Matter?

The conventional sequence of guideline-directed medical therapy (GDMT) initiation in heart failure with reduced ejection fraction (HFrEF) assumes that the effectiveness and tolerability of GDMT agents mirror their order of discovery, which is not true. In this review, the authors discuss flexible GDMT sequencing that should be permitted in special populations, such as patients with bradycardia, chronic kidney disease, or atrial fibrillation. Moreover, the initiation of certain GDMT medications may enable tolerance of other GDMT medications. Most importantly, the achievement of partial doses of all four pillars of GDMT is better than achievement of target dosing of only a couple.

Iron Deficiency in Heart Failure: A Scientific Statement from the Heart Failure Society of America

Iron deficiency is present in approximately 50% of patients with symptomatic heart failure and is independently associated with worse functional capacity, lower quality of, life and increased mortality. The purpose of this document is to summarize current knowledge of how iron deficiency is defined in heart failure and its epidemiology and pathophysiology, as well as pharmacological considerations for repletion strategies. This document also summarizes the rapidly expanding array of clinical trial evidence informing when, how, and in whom to consider iron repletion.

Effect of the structural modification of Candesartan with Zinc on hypertension and left ventricular hypertrophy

Hypertension is the most common cause of left ventricular hypertrophy, contributing to heart failure progression. Candesartan (Cand) is an angiotensin receptor antagonist widely used for hypertension treatment. Structural modifications were previously performed by our group using Zinc (ZnCand) as a strategy for improving its pharmacological properties. The measurements showed that ZnCand exerts a stronger interaction with the angiotensin II receptor, type 1 (AT1 receptor), reducing oxidative stress and intracellular calcium flux, a mechanism implied in cell contraction. These results were accompanied by the reduction of the contractile capacity of mesangial cells. In vivo experiments showed that the complex causes a significant decrease in systolic blood pressure after 8 weeks of treatment in spontaneously hypertensive rats (SHR). The reduction of heart hypertrophy was evidenced by echocardiography, the histologic cross-sectional area of cardiomyocytes, collagen content, the B-type natriuretic peptide (BNP) marker and connective tissue growth factor (CTGF) and the matrix metalloproteinase 2 (MMP-2) expression. Besides, the complex restored the redox status. In this study, we demonstrated that the complexation with Zn(II) improves the antihypertensive and cardiac effects of the parental drug.

Meta-Analysis on Drug and Device Therapy of New York Heart Association Functional Class IV Heart Failure With Reduced Ejection Fraction

Heart failure with reduced ejection fraction (HFrEF) is associated with significant morbidity and mortality, particularly in patients with New York Heart Association (NYHA) functional class IV symptoms. Decades of discovery have heralded significant advancements in the pharmacologic management of HFrEF. However, patients with NYHA IV symptoms remain an under-represented population in almost every clinical trial to date, leaving clinicians with limited evidence with which to guide drug treatment decisions in this patient group with severe heart failure. Randomized controlled trials of adult patients with NYHA IV symptoms of HFrEF randomized to current guideline-recommended medical therapy were included in this systematic review and meta-analysis. The outcomes of interest included the rate of all-cause mortality, cardiovascular mortality, and heart failure hospitalization. A total of 39 randomized controlled trials were included. A total of 6 studies examined angiotensin converting enzyme inhibitors, with meta-analyses of 2 demonstrating a reduced risk of all-cause mortality (relative risk (RR) 0.76, 95% confidence interval 0.59 to 0.97, p = 0.03). A total of 11 studies examined β blockers, with meta-analysis of 6 demonstrating a reduced risk of all-cause mortality (risk ratio 0.74, 95% confidence interval 0.60 to 0.92, p = 0.008). A study examined the mineralocorticoid antagonist spironolactone, reporting a reduced risk of all-cause mortality in the NYHA IV subgroup. A total of 6 studies examined device therapy, demonstrating the benefit of cardiac resynchronization therapy with or without an implantable cardiac defibrillator in reducing hospitalization in the NYHA IV subgroup. Although trial evidence exists for angiotensin converting enzyme inhibitors, β-blockers, and mineralocorticoid antagonist therapy in the NYHA IV population, the role of angiotensin receptor blockers is unclear. Ivabradine, angiotensin receptor neprilysin inhibitors, and sodium-glucose transport protein 2 inhibitors remain underinvestigated and have not been proved to provide any benefit above standard heart failure therapy in patients with HFrEF and NYHA IV symptoms.

Structural studies identify angiotensin II receptor blocker-like compounds as branched-chain ketoacid dehydrogenase kinase inhibitors

The mammalian mitochondrial branched-chain ketoacid dehydrogenase (BCKD) complex is a multienzyme complex involved in the catabolism of branched-chain amino acids. BCKD is regulated by the BCKD kinase, or BCKDK, which binds to the E2 subunit of BCKD, phosphorylates its E1 subunit, and inhibits enzymatic activity. Inhibition of the BCKD complex results in increased levels of branched-chain amino acids and branched-chain ketoacids, and this buildup has been associated with heart failure, type 2 diabetes mellitus, and nonalcoholic fatty liver disease. To find BCKDK inhibitors for potential treatment of these diseases, we performed both NMR and virtual fragment screening and identified tetrazole-bearing fragments that bind BCKDK at multiple sites. Through structure-based virtual screening expanding from these fragments, the angiotensin receptor blocker class antihypertension drugs and angiotensin receptor blocker-like compounds were discovered to be potent BCKDK inhibitors, suggesting potential new avenues for heart failure treatment combining BCKDK inhibition and antihypertension.

Angiotensinogen: More Than its Downstream Products: Evidence From Population Studies and Novel Therapeutics

The renin-angiotensin-aldosterone system (RAAS) is a well-defined pathway playing a key role in maintaining circulatory homeostasis. Abnormal activation of RAAS contributes to development of cardiovascular disease, including heart failure, cardiac hypertrophy, hypertension, and atherosclerosis. Although several key RAAS enzymes and peptide hormones have been thoroughly investigated, the role of angiotensinogen-the precursor substrate of the RAAS pathway-remains less understood. The study of angiotensinogen single-nucleotide polymorphisms (SNPs) has provided insight into associations between angiotensinogen and hypertension, congestive heart failure, and atherosclerotic cardiovascular disease. Targeted drug therapy of RAAS has dramatically improved clinical outcomes for patients with heart failure, myocardial infarction, and hypertension. However, all such therapeutics block RAAS components downstream of angiotensinogen and elicit compensatory pathways that limit their therapeutic efficacy as monotherapy. Upstream RAAS targeting by an angiotensinogen inhibitor has the potential to be more efficacious in patients with suboptimal RAAS inhibition and has a better safety profile than multiagent RAAS blockade. Newly developed therapeutics that target angiotensinogen through antisense oligonucleotides or silencer RNA technologies are providing a novel perspective into the pathobiology of angiotensinogen and show promise as the next frontier in the treatment of cardiovascular disease.

Role of CCR2-Positive Macrophages in Pathological Ventricular Remodelling

Even with recent advances in care, heart failure remains a major cause of morbidity and mortality, which urgently needs new treatments. One of the major antecedents of heart failure is pathological ventricular remodelling, the abnormal change in the size, shape, function or composition of the cardiac ventricles in response to load or injury. Accumulating immune cell subpopulations contribute to the change in cardiac cellular composition that occurs during ventricular remodelling, and these immune cells can facilitate heart failure development. Among cardiac immune cell subpopulations, macrophages that are recognized by their transcriptional or cell-surface expression of the chemokine receptor C-C chemokine receptor type 2 (CCR2), have emerged as playing an especially important role in adverse remodelling. Here, we assimilate the literature that has been generated over the past two decades describing the pathological roles that CCR2+ macrophages play in ventricular remodelling. The goal is to facilitate research and innovation efforts in heart failure therapeutics by drawing attention to the importance of studying the manner by which CCR2+ macrophages mediate their deleterious effects.

Rational drug therapy of chronic heart failure: the role of mineralocorticoid receptor antagonists: review

Mineralocorticoid receptor antagonists (MRAs) are part of basic medical therapy for heart failure. The clinical efficacy of MRAs has been proven by randomized clinical trials. To review comparative efficacy and tolerability data between the two main MRAs, spironolactone and eplerenone, in patients with systolic heart failure.

Mechanisms for the development of heart failure and improvement of cardiac function by angiotensin-converting enzyme inhibitors

Angiotensin-converting enzyme (ACE) inhibitors, which prevent the conversion of angiotensin I to angiotensin II, are well-known for the treatments of cardiovascular diseases, such as heart failure, hypertension and acute coronary syndrome. Several of these inhibitors including captopril, enalapril, ramipril, zofenopril and imidapril attenuate vasoconstriction, cardiac hypertrophy and adverse cardiac remodeling, improve clinical outcomes in patients with cardiac dysfunction and decrease mortality. Extensive experimental and clinical research over the past 35 years has revealed that the beneficial effects of ACE inhibitors in heart failure are associated with full or partial prevention of adverse cardiac remodeling. Since cardiac function is mainly determined by coordinated activities of different subcellular organelles, including sarcolemma, sarcoplasmic reticulum, mitochondria and myofibrils, for regulating the intracellular concentration of Ca2+ and myocardial metabolism, there is ample evidence to suggest that adverse cardiac remodelling and cardiac dysfunction in the failing heart are the consequence of subcellular defects. In fact, the improvement of cardiac function by different ACE inhibitors has been demonstrated to be related to the attenuation of abnormalities in subcellular organelles for Ca2+-handling, metabolic alterations, signal transduction defects and gene expression changes in failing cardiomyocytes. Various ACE inhibitors have also been shown to delay the progression of heart failure by reducing the formation of angiotensin II, the development of oxidative stress, the level of inflammatory cytokines and the occurrence of subcellular defects. These observations support the view that ACE inhibitors improve cardiac function in the failing heart by multiple mechanisms including the reduction of oxidative stress, myocardial inflammation and Ca2+-handling abnormalities in cardiomyocytes.

Disease-modifier Drugs in Patients with Advanced Heart Failure: How to Optimize Their Use?

Therapy based on disease-modifier drugs is among the required criteria to diagnose advanced heart failure (AdvHF). Nevertheless, several conditions, such as hospitalization, hypotension, renal dysfunction, electrolyte abnormalities, medical inertia, and patients' adherence, can make the maintenance of optimal medical therapy in patients with AdvHF challenging. Moreover, in recent years, new classes of drugs able have been shown to be able to further modify the natural history of heart failure with reduced ejection fraction, but they are still not widely adopted. This article discusses the optimal use of disease-modifier drugs in patients with AdvHF as well as the possible usefulness of the new therapeutic opportunities.

Sex-related differences in the pharmacological treatment of heart failure

Heart failure (HF) represents a leading cause of morbidity and mortality. However, HF trials highlighted many differences between men and women with HF. Thus, women represent approximately a quarter of people with HF with reduced ejection fraction (HFrEF), while they account for over half of those with HF with preserved EF (HFpEF). There are also sex-related differences (SRDs) in the pharmacokinetics, pharmacodynamics and safety profile of some guideline-recommended drugs for the treatment of HF. As compared with men, women with HFrEF are less often treated with guideline-recommended HF drugs, experience more frequent and severe adverse reactions when these drugs are prescribed at the same doses in both sexes, and recent evidence suggests that women might need lower doses than men, bringing into question which are the optimal doses of HF drugs in women and men separately. However, information on SRDs in drug efficacy and safety in patients with HFrEF is very limited due to the underrepresentation of women and the lack of sex-specific evaluations of drug efficacy and safety in HF clinical trials. As a consequence, current clinical guidelines do not provide sex-specific recommendations, even when significant differences exist, at least, in drug safety. The aim of this article is to review the SRDs in the pharmacokinetics, efficacy and safety of guideline-recommended HF drugs and to identify emerging areas of research to improve our understanding of the SRDs, because a better understanding of these differences is the first step to achieve a personalized treatment of HF in women and men.

The pharmacotherapeutic management of hyperkalemia in patients with cardiovascular disease

Introduction: Patients with cardiovascular diseases (CVD) are at increased risk of hyperkalemia, particularly when treated with renin-angiotensin-aldosterone inhibitors (RAASIs). Because the occurrence or fear of hyperkalemia, RAASIs are frequently down-titrated or discontinued in patients with CVD, with consequent worse outcomes than patients who remain on maximum doses.Areas covered: This article reviews potassium homeostasis, epidemiology, risk factors, and outcomes of hyperkalemia, and efficacy and safety of the drugs used for acute and chronic treatment of hyperkalemia. A literature search was carried out using the PubMed and guidelines for the management of hyperkalemia.Expert opinion: The emergency treatment of hyperkalemia is not supported by high-quality evidence and clinical trials did not report drug effects on clinical outcomes. Two potassium binders, patiromer and sodium zirconium cyclosilicate, represent a new approach in the treatment of chronic hyperkalemia as they may allow the titration and maintenance of guidelines-recommended doses of RAASIs in patients with CVD who otherwise would not tolerate them due to the risk of hyperkalemia.Further studies are needed to evaluate the safety and efficacy of drug therapy and support the development of guidelines for acute and chronic hyperkalemia.

Cardiac Mineralocorticoid Receptor and the Na+/H+ Exchanger: Spilling the Beans

Current evidence reveals that cardiac mineralocorticoid receptor (MR) activation following myocardial stretch plays an important physiological role in adapting developed force to sudden changes in hemodynamic conditions. Its underlying mechanism involves a previously unknown nongenomic effect of the MR that triggers redox-mediated Na⁺/H⁺ exchanger (NHE1) activation, intracellular Na⁺ accumulation, and a consequent increase in Ca²⁺ transient amplitude through reverse Na⁺/Ca²⁺ exchange. However, clinical evidence assigns a detrimental role to MR activation in the pathogenesis of severe cardiac diseases such as congestive heart failure. This mini review is meant to present and briefly discuss some recent discoveries about locally triggered cardiac MR signals with the objective of shedding some light on its physiological but potentially pathological consequences in the heart.

Reversion of cardiovascular remodelling in renovascular hypertensive 2K-1C rats by renin-angiotensin system inhibitors

OBJECTIVES

Evaluate whether the RAS dual blockade would induce additional beneficial effects on cardiovascular remodelling when compared to monotherapy in renal hypertensive two kidneys-one clip (2K-1C) rats.

METHODS

Hypertensive 2K-1C and normotensive (2K) rats were treated for 14 days with submaximal doses of losartan (LOS), enalapril (ENA), losartan plus enalapril (LOS + ENA) or vehicle (water). Blood pressure and some parameters of cardiovascular remodelling were evaluated.

RESULTS

Systolic blood pressure (SBP) was higher in 2K-1C (209 ± 3 mm Hg, P < .05) than in 2K (113 ± 1 mm Hg) rats. There was an additional effect in 2K-1C treated with LOS + ENA (153 ± 9 mm Hg) on lowering SBP when compared to LOS (184 ± 12 mm Hg) or ENA (177 ± 9 mm Hg). None of the treatments had effect on SBP in 2K rats. In 2K-1C, cardiomyocyte hypertrophy was reduced by all treatments, although the cardiac hypertrophy indexes remained unchanged. 2K-1C aortas presented medial thickening that was partially reduced by the treatments. Intimal hyperplasia observed in 2K-1C (15.56 ± 0.89 µm vs 8.24 ± 0.80 µm) was reversed by ENA (9.52 ± 0.45 µm) or LOS + ENA (8.17 ± 0.53 µm). Collagen deposition was increased in 2K-1C hearts (1.77 ± 0.16 vs 1.28 ± 0.09) and aortas (8.1 ± 0.6 vs 5.2 ± 0.2). Treatment with LOS reduced (1.12 ± 0.14%) and ENA (0.81 ± 0.11%) or LOS + ENA (0.86 ± 0.11%) additionally diminished collagen only in 2K-1C hearts.

CONCLUSIONS

Submaximal doses of ACEi and/or ARB have inhibitory actions on cardiac remodelling and vascular hypertrophy not entirely dependent on their effects on blood pressure normalization in renovascular hypertensive rats. Combined therapy produced additional reduction in blood pressure than monotherapy despite a similar inhibition on cardiovascular remodelling.

Effects of eplerenone on cerebral aldosterone levels and brain lesions in spontaneously hypertensive rats

Evidence indicates that renin-angiotensin-aldosterone system (RAS) inhibitors can protect the brain in Alzheimer's disease and Parkinson's disease. The current study evaluated the relationship between aldosterone and tissue damage in the brains of spontaneously hypertensive rats (SHRs) and whether the RAS inhibitor eplerenone can mitigate the damage seen in these rats. SHRs were randomly divided into eplerenone (n = 10) and SHR (n = 10) groups, and Wistar-Kyoto (WKY) rats (n = 10) were used as controls. Eplerenone 50 mg/kg/day was administered orally to the eplerenone group. Pathological changes to the hippocampal formation, plasma and encephalic aldosterone, and plasma potassium levels were compared among the groups. After 10 weeks, rats in the eplerenone and SHR groups showed higher systolic BP (p = .01) than the control group. Aldosterone levels in the brain were higher in the SHR group (0.20 ± 0.06 pg/ml) than in the eplerenone (0.14 ± 0.05 pg/ml, p = .044) or control (0.12 ± 0.07 pg/ml, p = .007) groups. Plasma aldosterone levels in the SHR group were 1.7 times higher than those in the control group (p = .006). Cerebral cortex was thinner in the SHR group (225.18 ± 15.43 μm) than in the eplerenone (240.38 ± 12.85 μm, p < .01) or control (244.72 ± 18.92 μm, p < .01) groups. Thickness did not differ between the latter two groups. The SHR group exhibited apoptotic cells in the hippocampal formation, which were rare in the eplerenone and control groups. Plasma potassium levels were higher in the eplerenone group than those in the other two groups (p < .05). Our results showed that eplerenone can alleviate brain damage (thinning of cortex and increased apoptosis) caused by aldosterone in a rat model of hypertension.

Effects of dual blockade in heart failure and renal dysfunction: Systematic review and meta-analysis

OBJECTIVE

The effect of dual renin-angiotensin system (RAS) inhibition in heart failure (HF) is still controversial. Systematic reviews have shown that dual RAS blockade may reduce mortality and hospitalizations, yet it has been associated with the increased risk of renal dysfunction (RD). Surprisingly, although RD in patients with HF is frequent, the effect of combining RAS inhibitors in HF patients with RD has never been studied in a meta-analysis.

METHODS

A systematic review and meta-analysis of randomized clinical trials involving HF patients with RD who received dual blockade analyzing death, cardiovascular (CV) death or HF hospitalization, and adverse events.

RESULTS

Out of 2258 screened articles, 12 studies were included (34,131 patients). Compared with monotherapy, dual RAS inhibition reduced hazard ratio of death to 0.94 (p=0.07) and significantly reduced CV death or HF hospitalization to 0.89 (p=0.0006) in all individuals, and to 0.86 (p=0.005) in patients with RD and to 0.91 (p=0.04) without RD. Nevertheless, dual RAS blockade significantly increased the risk of renal impairment (40%), hyperkalemia (44%), and hypotension (42%), although discontinuation of treatment occurs only in 3.68% versus 2.19% (p=0.00001).

CONCLUSIONS

Dual RAS inhibition therapy reduces the risk of CV death or HF hospitalization. However, cautions monitoring for specific adverse events may be warranted.

The role of N-terminal pro-B-type natriuretic peptide in prognostic evaluation of heart failure

Heart failure (HF) is a growing challenge in the Asia Pacific region. N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a well-established tool for diagnosis of HF; however, it is relatively underutilized in predicting adverse outcomes in HF. Multiple studies have demonstrated the prognostic role of NT-proBNP in HF. A single value of NT-proBNP >5000 pg/mL predicts a worse outcome in hospitalized patients with HF with reduced ejection fraction (HFrEF). In stable outpatients with HFrEF, NT-proBNP > 1000 pg/mL predicts a poorer prognosis. NT-proBNP provides the same prognostic information in patients with HF with preserved ejection fraction (HFpEF) as in those with HFrEF. An expert panel composed of cardiologists mainly from Asia Pacific region was convened to discuss the utility of NT-proBNP in HF prognostication. This article summarizes available scientific evidence and consensus recommendations from the meeting.

The Limitations of Symptom-based Heart Failure Management

Heart failure (HF) has emerged as a global epidemic and it affects about 6 million adults in the US. HF medical treatment, as recommended in guidelines, significantly improves survival and quality of life; however, the mortality burden of HF remains high. For decades, treatment has been guided, mainly by symptoms, leading to undertreatment in a range of settings. Current evidence emphasises the unfavourable outcomes of HF even in early stages or in patients who achieve reverse remodeling and remission or recovery under optimised treatment. This should stimulate efforts towards a more objective, rigorous management, covering the entire spectrum of mild, moderate and severe HF.

The Role of Mineralocorticoid Receptor Antagonists in Heart Failure with Reduced Ejection Fraction

Background:

Heart failure (HF) is a worldwide modern epidemic, associated with significant morbidity and mortality. Several causes have been identified for the syndrome, most of which share common pathophysiologic pathways, including neurohormonal activation. Central to the latter lies activation of the reninangiotensin- aldosterone system, and its effects on cardiovascular disease progression.

Objectives:

The aim of this review is to summarize the pathophysiology of aldosterone and the effects of its blockage in the failing heart, as well as to provide state-of-the-art evidence, and address future perspectives regarding the use of mineralocorticoid receptor antagonists in heart failure with reduced ejection fraction.

Method:

Literature was reviewed for studies that assess the pathophysiology of aldosterone in HF with reduced ejection fraction (HFrEF), and the effects of mineralocorticoid receptor antagonists (MRAs) in this condition.

Results:

Several major society guidelines have synthesized the available evidence on HFrEF management, and drugs that block the renin-angiotensin-aldosterone system at different levels continue to form the key component of standard of care for these patients. Mineralocorticoid receptor antagonists are an important part of HFrEF pharmacologic treatment, and their use is supported by a high level of evidence studies. This class of drugs demonstrated significant benefits for morbidity and mortality, across the spectrum oh HFrEF, including patients after acute myocardial infarction.

Conclusion:

Current evidence supports the central role of aldosterone in HFrEF progression, and the significant benefits on outcomes with the use of MRAs.

The renin-angiotensin-aldosterone system and its suppression

Chronic activation of the renin-angiotensin-aldosterone system (RAAS) promotes and perpetuates the syndromes of congestive heart failure, systemic hypertension, and chronic kidney disease. Excessive circulating and tissue angiotensin II (AngII) and aldosterone levels lead to a pro-fibrotic, -inflammatory, and -hypertrophic milieu that causes remodeling and dysfunction in cardiovascular and renal tissues. Understanding of the role of the RAAS in this abnormal pathologic remodeling has grown over the past few decades and numerous medical therapies aimed at suppressing the RAAS have been developed. Despite this, morbidity from these diseases remains high. Continued investigation into the complexities of the RAAS should help clinicians modulate (suppress or enhance) components of this system and improve quality of life and survival. This review focuses on updates in our understanding of the RAAS and the pathophysiology of AngII and aldosterone excess, reviewing what is known about its suppression in cardiovascular and renal diseases, especially in the cat and dog.

Long-Term Effects of Spironolactone on Kidney Function and Hyperkalemia-Associated Hospitalization in Patients with Chronic Kidney Disease

Background: Spironolactone, a non-selective mineralocorticoid receptor antagonist, can protect against cardiac fibrosis and left ventricular dysfunction, and improve endothelial dysfunction and proteinuria. However, the safety and effects of spironolactone on patient-centered cardiovascular and renal endpoints remain unclear. Methods: We identified predialysis stage 3–4 chronic kidney disease (CKD) patients between 2000 and 2013 from the Longitudinal Health Insurance Database 2005 (LHID 2005). The outcomes of interest were end-stage renal disease (ESRD), major adverse cardiovascular events (MACE), hospitalization for heart failure (HHF), hyperkalemia-associated hospitalization (HKAH), all-cause mortality and cardiovascular mortality. The Fine and Gray sub-distribution hazards approach was adopted to adjust for the competing risk of death. Results: After the propensity score matching, 693 patients with stage 3–4 CKD were spironolactone users and 1386 were nonusers. During the follow-up period, spironolactone users had a lower incidence rate for ESRD than spironolactone non-users (39.2 vs. 53.69 per 1000 person-years) and a higher incidence rate for HKAH (54.79 vs. 18.57 per 1000 person-years). The adjusted hazard ratios for ESRD of spironolactone users versus non-users were 0.66 (95% CI, 0.51–0.84; p value < 0.001) and 3.17 (95% CI, 2.41–4.17; p value < 0.001) for HKAH. A dose-response relationship was found between spironolactone use and risk of ESRD and HKAH. There were no statistical differences in MACE, HHF, all-cause mortality and cardiovascular mortality between spironolactone users and non-users. Conclusion: Spironolactone represented a promising treatment option to retard CKD progression to ESRD amongst stage 3–4 CKD patients, but strategic treatments to prevent hyperkalemia should be enforced.

Was the Enalapril Dose Too Low in the PARADIGM-HF Trial?

Heart failure (HF) is a common clinical syndrome associated with significant morbidity and mortality, and there remains a clear need for innovative therapies that can modify disease progression. Sacubitril/valsartan (LCZ696) is a novel complex that combines simultaneous neprilysin inhibition and angiotensin II receptor blockade, that has demonstrated significant cardiovascular death or HF hospitalization reduction in the Prospective Comparison of Angiotensin Receptor/Neprilysin Inhibitor (ARNI) With Angiotensin-Converting Enzyme (ACE) Inhibitors to Determine Impact on Global Mortality and Morbidity in Heart Failure (PARADIGM-HF) trial when compared with evidence-based doses of the gold standard ACE inhibitor enalapril. In this comprehensive review, the authors discuss historical trials that have investigated clinical outcomes utilizing variable dosing levels of ACE inhibitors or angiotensin receptor blockers in patients with HF with reduced ejection fraction. A critical analysis of the highlighted studies is proposed in the context of current HF management guidelines and HF clinical practice. In conclusion, based on current evidence, it is unclear whether a maximum recommended enalapril dose would promote improved patient outcomes compared with an intermediate dose. However, no prospective study to date comparing ACE inhibitor doses has documented that higher doses result in significant mortality reduction, although the data suggest that there may be a decrease in HF hospitalizations when compared with lower doses.

A prospective study of the impact of AGTR1 A1166C on the effects of candesartan in patients with heart failure

AIM

To evaluate the impact of AGTR1 A1166C (rs5186) on the response to candesartan in patients with heart failure.

MATERIALS & METHODS

Prospective, multicentre, open-label study. We studied 299 symptomatic patients with heart failure presenting a left ventricular ejection fraction ≤40%.

RESULTS

Reductions in the primary end points of natriuretic peptides were not significantly associated with AGTR1 A1166C. Nevertheless, carrying the 1166C allele was associated with a greater compensatory increase in renin activity (p = 0.037) after 16 weeks of treatment with candesartan and a more modest effect on aldosterone concentrations (p = 0.022).

CONCLUSION

AGTR1 1166C carriers may experience a greater long-term compensatory renin-angiotensin-aldosterone system activation following treatment with candesartan. Whether these associations ultimately influence clinical outcomes requires investigation. Clinicaltrials.gov : NCT00400582.

Type 2 diabetes mellitus and heart failure: a position statement from the Heart Failure Association of the European Society of Cardiology

The coexistence of type 2 diabetes mellitus (T2DM) and heart failure (HF), either with reduced (HFrEF) or preserved ejection fraction (HFpEF), is frequent (30-40% of patients) and associated with a higher risk of HF hospitalization, all-cause and cardiovascular (CV) mortality. The most important causes of HF in T2DM are coronary artery disease, arterial hypertension and a direct detrimental effect of T2DM on the myocardium. T2DM is often unrecognized in HF patients, and vice versa, which emphasizes the importance of an active search for both disorders in the clinical practice. There are no specific limitations to HF treatment in T2DM. Subanalyses of trials addressing HF treatment in the general population have shown that all HF therapies are similarly effective regardless of T2DM. Concerning T2DM treatment in HF patients, most guidelines currently recommend metformin as the first-line choice. Sulphonylureas and insulin have been the traditional second- and third-line therapies although their safety in HF is equivocal. Neither glucagon-like preptide-1 (GLP-1) receptor agonists, nor dipeptidyl peptidase-4 (DPP4) inhibitors reduce the risk for HF hospitalization. Indeed, a DPP4 inhibitor, saxagliptin, has been associated with a higher risk of HF hospitalization. Thiazolidinediones (pioglitazone and rosiglitazone) are contraindicated in patients with (or at risk of) HF. In recent trials, sodium-glucose co-transporter-2 (SGLT2) inhibitors, empagliflozin and canagliflozin, have both shown a significant reduction in HF hospitalization in patients with established CV disease or at risk of CV disease. Several ongoing trials should provide an insight into the effectiveness of SGLT2 inhibitors in patients with HFrEF and HFpEF in the absence of T2DM.

Aldosterone breakthrough does not alter central hemodynamics

Introduction:

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers are widely used in congestive heart failure and chronic kidney disease, but up to 40% of patients will experience aldosterone breakthrough, with aldosterone levels rising above pre-treatment levels after 6–12 months of renin-angiotensin-aldosterone system blockade. Aldosterone breakthrough has been associated with worsening congestive heart failure and chronic kidney disease, yet the pathophysiology remains unclear. Breakthrough has not been associated with elevated peripheral blood pressure, but no studies have assessed its effect on central blood pressure.

Methods:

Nineteen subjects with well-controlled peripheral blood pressure on stable doses of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker had aldosterone levels checked and central blood pressure parameters measured using the SphygmoCor system. The central blood pressure parameters of subjects with or without breakthrough, defined as serum aldosterone >15 ng/dl, were compared.

Results:

Of the 19 subjects, six had breakthrough with a mean aldosterone level of 33.8 ng/dl, and 13 were without breakthrough with a mean level of 7.1 ng/dl. There was no significant difference between the two groups in any central blood pressure parameter.

Conclusions:

We found no correlation between aldosterone breakthrough and central blood pressure. The clinical impact of aldosterone breakthrough likely depends on its non-genomic, pro-fibrotic, pro-inflammatory effects rather than its regulation of extracellular volume.

Effect of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers on cardiovascular events in patients with heart failure: a meta-analysis of randomized controlled trials

Background

Heart failure (HF) remains a significant cause of morbidity and mortality. Multiple trials over the past several years have examined the effects of both angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) in the treatment of left ventricular dysfunction, both acutely after myocardial infarction and in chronic heart failure. Yet, there is still confusion regarding the relative efficacy of rennin-angiotensin-aldosterone system (RAAS) inhibition. Our study was conducted to assess efficacy of ACEIs and ARBs in reducing all-cause and cardiovascular mortality in heart failure patients.

Methods

We included randomized clinical trials compared ACEIs and ARBs treatment (any dose or type) with placebo treatment, no treatment, or other anti-HF drugs treatment, reporting cardiovascular or total mortality with an observation period of at least 12 months. Data sources included Pubmed, EMBASE, the Cochrane Central Register of Controlled Trials. Dichotomous outcome data from individual trials were analyzed using the risk ratio measure and its 95%CI with random-effects/ fixed-effects models. We performed meta-regression analyses to identify sources of heterogeneity. All-cause mortality and CV mortality were thought to be the main outcomes.

Results

A total of 47,662 subjects were included with a mean/median follow-up ranged from 12 weeks to 4.5 years. Of all 38 studies, 32 compared ACEIs with control therapy (included 13 arms that compared ACEIs with placebo, 10 arms in which the comparator was active treatment and 9 arms that compared ACEIs with ARBs), and six studies compared ARBs with placebo. ACEIs treatment in patients with HF reduced all-cause mortality to 11% (risk ratio (RR): 0.89, 95% confidence interval (CI): 0.83–0.96, p = 0.001) and the corresponding value for cardiovascular mortality was 14% (RR: 0.86, 95% CI: 0.78–0.94, p = 0.001). However, ARBs had no beneficial effect on reducing all-cause and cardiovascular mortality. In head-to-head analysis, ACEIs was not superior to ARBs for all-cause mortality and cardiovascular deaths.

Conclusions

In HF patients, ACEIs, but not ARBs reduced all-cause mortality and cardiovascular deaths. Thus, ACEIs should be considered as first-line therapy to limit excess mortality and morbidity in this population.

Electronic supplementary material

The online version of this article (10.1186/s12872-017-0686-z) contains supplementary material, which is available to authorized users.

Mechanisms contributing to cardiac remodelling

Cardiac remodelling is classified as physiological (in response to growth, exercise and pregnancy) or pathological (in response to inflammation, ischaemia, ischaemia/reperfusion (I/R) injury, biomechanical stress, excess neurohormonal activation and excess afterload). Physiological remodelling of the heart is characterized by a fine-tuned and orchestrated process of beneficial adaptations. Pathological cardiac remodelling is the process of structural and functional changes in the left ventricle (LV) in response to internal or external cardiovascular damage or influence by pathogenic risk factors, and is a precursor of clinical heart failure (HF). Pathological remodelling is associated with fibrosis, inflammation and cellular dysfunction (e.g. abnormal cardiomyocyte/non-cardiomyocyte interactions, oxidative stress, endoplasmic reticulum (ER) stress, autophagy alterations, impairment of metabolism and signalling pathways), leading to HF. This review describes the key molecular and cellular responses involved in pathological cardiac remodelling.

Prognostic Implications of Changes in N-Terminal Pro-B-Type Natriuretic Peptide in Patients With Heart Failure

BACKGROUND

Natriuretic peptides (NP) have prognostic value in heart failure (HF), although the clinical importance of changes in NP from baseline is unclear.

OBJECTIVES

The authors assessed whether a reduction in N-terminal pro-B-type NP (NT-proBNP) was associated with a decrease in HF hospitalization and cardiovascular mortality (primary endpoint) in patients with HF and reduced ejection fraction, whether treatment with sacubitril/valsartan reduced NT-proBNP below specific partition values more than enalapril, and whether the relationship between changes in NT-proBNP and changes in the primary endpoint were dependent on assigned treatment.

METHODS

In PARADIGM-HF (Prospective Comparison of ARNI [Angiotensin Receptor-Neprilysin Inhibitor] with ACEI [Angiotensin-Converting-Enzyme Inhibitor] to Determine Impact on Global Mortality and Morbidity in Heart Failure Trial), baseline NT-proBNP was measured in 2,080 patients; 1,292 had baseline values >1,000 pg/ml and were reassessed at 1 and 8 months. We related change in NT-proBNP to outcomes.

RESULTS

One month after randomization, 24% of the baseline NT-proBNP levels >1,000 pg/ml had fallen to ≤1,000 pg/ml. Risk of the primary endpoint was 59% lower in patients with a fall in NT-proBNP to ≤1,000 pg/ml than in those without such a fall. In sacubitril/valsartan-treated patients, median NT-proBNP was significantly lower 1 month after randomization than in enalapril-treated patients, and it fell to ≤1,000 pg/ml in 31% versus 17% of patients treated with sacubitril/valsartan and enalapril, respectively. There was no significant interaction between treatment and the relationship between change in NT-proBNP and the subsequent risk of the primary endpoint.

CONCLUSIONS

Patients who attained a significant reduction in NT-proBNP had a lower subsequent rate of cardiovascular death or HF hospitalization independent of the treatment group. Treatment with sacubitril/valsartan was nearly twice as likely as enalapril to reduce NT-proBNP to values ≤1,000 pg/ml. (Prospective Comparison of ARNI [Angiotensin Receptor-Neprilysin Inhibitor] with ACEI [Angiotensin-Converting-Enzyme Inhibitor] to Determine Impact on Global Mortality and Morbidity in Heart Failure Trial) [PARADIGM-HF]; NCT01035255.).

Natriuretic Peptides, 6-Min Walk Test, and Quality-of-Life Questionnaires as Clinically Meaningful Endpoints in HF Trials

The Expedited Access for Premarket Approval and De Novo Medical Devices Intended for Unmet Medical Need for Life Threatening or Irreversibly Debilitating Diseases or Conditions document was issued as a guidance for industry and for the Food and Drug Administration. The Expedited Access Pathway was designed as a new program for medical devices that demonstrated the potential to address unmet medical needs for life threatening or irreversibly debilitating conditions. The Food and Drug Administration would consider assessments of a device's effect on intermediate endpoints that, when improving in a congruent fashion, are reasonably likely to predict clinical benefit. The purpose of this review is to provide evidence to support the use of 3 such intermediate endpoints: natriuretic peptides, such as N-terminal pro-B-type natriuretic peptide/B-type natriuretic peptide, the 6-min walk test distance, and health-related quality of life in heart failure.

Differential efficacy profile of aldosterone receptor antagonists, depending on the type of chronic heart failure, whether with reduced or preserved left ventricular ejection fraction-results of a meta-analysis of randomized controlled trials

BACKGROUND

Because of renin-angiotensin-aldosterone system (RAAS) activation, the patients with chronic heart failure (CHF) manifest increased ventricular stress, with impaired left ventricular function, and a slowing down in systemic venous drainage. More importantly, a reduction of the patient's life expectancy has been proven in the case of RAAS overstimulation. For these reasons, huge efforts have been made to obtain molecules able to efficaciously antagonize the RAAS overstimulation, such as aldosterone receptor antagonists (ARAs). These drugs have been shown to improve clinical outcomes in patients with heart failure with reduced left ventricular ejection fraction (HFREF), but not in those with preserved left ventricular ejection fraction (HFpEF). In order to study this topic more deeply, we carried out a meta-analysis of selective and nonselective ARAs in HFREF and HFpEF.

METHODS

Only randomized controlled trials (RCTs) were incorporated in our meta-analysis. Studies were included if they satisfied the following criteria: experimental groups included patients with CHF treated with ARAs in addition to the conventional therapy; control groups included patients with CHF receiving conventional therapy without ARAs. Outcomes of interest were all-cause mortality, cardiovascular hospitalizations, hyperkalemia, or gynecomastia.

RESULTS

Overall, 15 RCTs including a total of 15,671 patients were eligible for inclusion in the meta-analysis. ARA use in patients with heart failure was associated with a significant reduction in adverse outcomes. Indeed, a significant reduced odds of all-cause death among CHF patients treated with ARAs compared to controls was found [odds ratio (OR) =0.79; 95% CI: 0.73-0.87]. Subgroup analysis based on the heart failure (HF) type revealed a statistically significant benefit as regards all- cause death for patients with HFREF (OR =0.77; 95% confidence interval (CI): 0.69-0.84), but not for those with HFpEF (OR =0.91; 95% CI: 0.76-1.1). Furthermore reduced odds of CV hospitalizations was detected in the entire group of CHF patients under treatment with ARAs (OR =0.73; 95% CI: 0.61-0.89) as well as among HFREF patients treated with ARAs, compared to controls (OR =0.66; 95% CI: 0.51-0.85). Hyperkalemia was significantly more frequent with ARA use. Besides, ARA use was shown to be associated with the occurrence of gynecomastia. In particular, selective ARAs didn't induce significant amounts of gynecomastia compared to controls (OR =0.74; 95% CI: 0.43-1.27), while nonselective ARAs did (OR =8.22; 95% CI: 4.9-13.81).

CONCLUSIONS

Based on this meta-analysis, ARAs should be systematically used in patients with HFREF, in whom these drugs proved to reduce all-cause mortality and hospitalizations from cardiac cause. Conversely, ARA usage in HFpEF patients is questionable since in this CHF setting no significant improvement in clinical endpoints has been demonstrated so far. New selective ARAs are devoid of the risk of gynecomastia, while are similar to nonselective ARAs with regard to the efficacy profile as well as to the risk of eliciting hyperkalemia.

Biased agonism/antagonism at the AngII-AT1 receptor: Implications for adrenal aldosterone production and cardiovascular therapy

Many of the effects of angiotensin II (AngII), including adrenocortical aldosterone release, are mediated by the AngII type 1 receptor (AT₁R), a receptor with essential roles in cardiovascular homeostasis. AT₁R belongs to the G protein-coupled receptor (GPCR) superfamily, mainly coupling to the G_q/11 type of G proteins. However, it also signals through βarrestins, oftentimes in parallel to eliciting G protein-dependent signaling. This has spurred infinite possibilities for cardiovascular pharmacology, since various beneficial effects are purportedly exerted by AT₁R via βarrestins, unlike AT₁R-induced G protein-mediated pathways that usually result in damaging cardiovascular effects, including hypertension and aldosterone elevation. Over the past decade however, a number of studies from our group and others have suggested that AT₁R-induced βarrestin signaling can also be damaging for the heart, similarly to the G protein-dependent one, with regard to aldosterone regulation. Additionally, AT₁R-induced βarrestin signaling in astrocytes from certain areas of the brain may also play a significant role in central regulation of blood pressure and hypertension pathogenesis. These findings have provided the impetus for testing available angiotensin receptor blockers (ARBs) in their efficacy towards blocking both routes (i.e. both G protein- and βarrestin-dependent) of AT₁R signaling in vitro and in vivo and also have promoted structure-activity relationship (SAR) studies for the AngII molecule in terms of βarrestin signaling to certain cellular effects, e.g. adrenal aldosterone production. In the present review, we will recount all of these recent studies on adrenal and astrocyte AT₁R-dependent βarrestin signaling while underlining their implications for cardiovascular pathophysiology and therapy.

Influence of atrial fibrillation on post-discharge natriuretic peptide trajectory and clinical outcomes among patients hospitalized for heart failure: insights from the ASTRONAUT trial

AIMS

Change in NT-proBNP level is a common surrogate endpoint in early phase heart failure (HF) trials, but whether this endpoint is influenced by atrial fibrillation/flutter (AFF) is unclear.

METHODS AND RESULTS

This analysis included 1358 patients from the ASTRONAUT trial, which randomized patients hospitalized for HF with EF ≤40% to aliskiren or placebo in addition to standard care. Patients were stratified by presence of AFF on baseline ECG. NT-proBNP was measured longitudinally by a core laboratory at baseline, 1 month, 6 months, and 12 months. Compared with non-AFF patients, AFF patients experienced greater reduction from baseline in log-transformed NT-proBNP (interaction P < 0.001), but this difference was not significant after adjustment (interaction P = 0.726). The ability of aliskiren to lower NT-proBNP during follow-up differed by AFF status (interaction P = 0.001), with aliskiren lowering NT-proBNP more than placebo among non-AFF patients only. After adjustment, baseline AFF was not associated with mortality or HF hospitalization at 12 months (all P ≥ 0.152).

CONCLUSION

In this hospitalized HF cohort, AFF status did not influence post-discharge NT-proBNP trajectory or clinical outcomes after adjustment for patient characteristics. Aliskiren lowered follow-up NT-proBNP levels in patients without AFF, but had no influence among patients with AFF. This study generates the hypothesis that the ability of a HF trial to meet an NT-proBNP defined endpoint may be influenced by the prevalence of AFF in the population. Because aliskiren did not improve outcomes in patients without AFF, this analysis suggests changes in NT-proBNP induced by investigational therapies may be dissociated from clinical effects.

The Impact Exerted on Clinical Outcomes of Patients With Chronic Heart Failure by Aldosterone Receptor Antagonists: A Meta-Analysis of Randomized Controlled Trials

Background

Aldosterone receptor antagonists (ARAs) have been associated with improved clinical outcomes in patients with heart failure with reduced left ventricular ejection fraction (HFREF), but not in those with heart failure with preserved left ventricular ejection fraction (HFpEF). With the aim to study this topic more deeply, we carried out a meta-analysis of selective and non-selective ARAs in HFREF and HFpEF.

Methods

We searched PubMed and Scopus databases. We decided to incorporate in the meta-analysis only randomized controlled trials (RCTs) of ARAs in patients with chronic heart failure (CHF) if they met the following criteria: experimental groups included patients with CHF treated with ARAs in addition to the conventional therapy; control groups included patients with CHF receiving conventional therapy without ARAs. Outcomes of interest were all-cause death, hospitalizations from cardiovascular cause, hyperkalemia, or gynecomastia.

Results

We detected 15 studies representing 15,671 patients. ARAs were associated with a reduced odds of all-cause death (odds ratio (OR): 0.79; 95% confidence interval (CI): 0.73 - 0.87) and hospitalizations from cardiovascular cause (OR: 0.73; 95% CI: 0.61 - 0.89). However, subgroup analysis showed that these advantages were limited to HFREF (all-cause death: OR: 0.77, 95% CI: 0.69 - 0.84; hospitalizations from cardiovascular cause: OR: 0.66, 95% CI: 0.51 - 0.85), but they did not affect the HFpEF group (all-cause death: OR: 0.91, 95% CI: 0.76 - 1.1; hospitalizations from cardiovascular cause: OR: 0.85, 95% CI: 0.7 - 1.09). ARAs increased the risk of hyperkalemia (OR: 2.17; 95% CI: 1.88 - 2.5). Non-selective ARAs, but not selective ARAs, increased the risk of gynecomastia (OR: 8.22, 95% CI: 4.9 - 13.81 vs. OR: 0.74, 95% CI: 0.43 - 1.27).

Conclusions

ARAs reduced the risk of adverse cardiac events in HFREF but not HFpEF. In particular, ARA use in HFpEF patients is questionable, since in this CHF type, no significant improvement in all-cause death and cardiovascular hospitalizations was demonstrated with ARA treatment, in the face of the well-known risks of hyperkalemia and/or gynecomastia that chronic ARA therapy entails. Selective ARAs were equally effective as non-selective ARAs, without the risk of gynecomastia.

Cardioprotective effects of angiotensin II type 1 receptor blockade with candesartan after reperfused myocardial infarction: role of angiotensin II type 2 receptor

To determine whether angiotensin II (Ang II) type 2 (AT2)-receptor activation associated with cardioprotection induced by Ang II type 1 (AT1)-receptor blockade during ischaemia-reperfusion (IR) might be reflected in increased AT 2-receptor, IP3-(1,4,5- inositol trisphosphate type 2) receptor and PKC-ε (protein kinase C-ε) proteins and tissue cGMP (cyclic guanosine monophosphate), we measured in vivo left ventricular (LV) systolic and diastolic function and remodelling (echocardiogram/Doppler) and haemodynamics, and ex vivo infarct size, AT1-/AT 2receptor, IP3-receptor and PKC-ε proteins (immunoblots) and cGMP (enzyme immunoassay) in dogs with reperfused anterior acute myocardial infarction (MI) (90-minute ischaemia, 120-minute reperfusion). Compared with controls (C, n=6) in vivo, candesartan (1 mg/kg i.v. over 30-minute pre-ischaemia, n=6) effectively inhibited the Ang II pressor response (Δ%, -14±22% vs. -80±11, p<0.003) and decreased preload (122±35 vs. -2±16%, p<0.01), improved LV systolic ejection fraction (-29±4 vs. -11±5, p<0.03) and diastolic function (E/A ratio, -25±7 vs. 33±13, p<0.004), decreased the extent of LV asynergy (26±20 vs. -31±10% LV, p<0.05) and limited acute LV remodelling (expansion index 19±6 vs. -3±5, p<0.05; thinning ratio -22±2 vs. -4±2, p<0.0003). Ex vivo, candesartan decreased infarct size (55±2 vs. 27±2% risk, p<0.001) and increased infarct zone (IZ) AT2 -receptor protein by 8-fold (but not AT1-receptor protein), IP3-receptor protein by 12-fold, PKC-ε protein by 5-fold and cGMP by 40%. Cardioprotective effects of AT1-receptor blockade on acute IR injury, LV function, and remodelling may also involve AT 2-receptor activation and downstream signalling via IP3-receptor, PKC-ε and cGMP.

Review: Aldosterone — the future challenge in cardiovascular disease?

Mineralocorticoid receptor activation plays a key role in cardiovascular disease and hypertension, which are particularly prevalent in diabetes mellitus; secondary hyperaldosteronism contributes to cardiac failure. Major intervention trials in heart failure have demonstrated unequivocal benefit from aldosterone receptor antagonism. Focused experimental studies in humans and in animal models of hypertension have shown that aldosterone blockade improves a number of pathogenic abnormalities including vascular endothelial dysfunction and altered baroreflex function, and prevents the development of cardiac hypertrophy and renal histological damage. Based on recent outcomes studies, the challenge is now to transfer the experimental evidence into clinical M practice.