"Escape" of aldosterone production in patients with left ventricular dysfunction treated with an angiotensin converting enzyme inhibitor: implications for therapy

Aldosterone Effect on Cardiac Structure and Function

BACKGROUND

Cardiac remodelling could be a key mechanism in aldosteronemediated cardiovascular morbidity and mortality. Experimental and clinical evidence has demonstrated that aldosterone causes cardiac structural remodelling and dysfunction by its profibrotic and pro-hypertrophic effects, which result mainly from the direct effects on myocardial collagen deposition, inflammation, and oxidative stress. Clinical studies have investigated the aldosterone effects on the heart in different clinical conditions, including general population, essential hypertension, primary aldosteronism, heart failure, and atrial fibrillation. Robust findings indicate that aldosterone or the activation of the cardiac mineralocorticoid receptor can cause damage to myocardial tissue by mechanisms independent of the blood pressure, leading to tissue hypertrophy, fibrosis, and dysfunction.

CONCLUSION

Aldosterone-mediated cardiovascular morbidity and mortality mainly result from cardiac structural and functional alterations. In different clinical settings, aldosterone can induce cardiac structural remodelling and dysfunction via several pathological mechanisms, including cardiac fibrosis, inflammation, and oxidative stress. Aldosterone antagonists could effectively decrease or reverse the detrimental aldosterone-mediated changes in the heart.

Promise of Physiological Profiling to Prevent Stroke in People of African Ancestry: Prototyping Ghana

PURPOSE OF REVIEW

Worldwide, compared to other racial/ethnic groups, individuals of African ancestry have an excessively higher burden of hypertension-related morbidities, especially stroke. Identifying modifiable biological targets that contribute to these disparities could improve global stroke outcomes. In this scoping review, we discuss how pathological perturbations in the renin-angiotensin-aldosterone pathways could be harnessed via physiological profiling for the purposes of improving blood pressure control for stroke prevention among people of African ancestry.

RECENT FINDINGS

Transcontinental comparative data from the USA and Ghana show that the prevalence of treatment-resistant hypertension among stroke survivors is 42.7% among indigenous Africans, 16.1% among African Americans, and 6.9% among non-Hispanic Whites, p < 0.0001. A multicenter clinical trial of patients without stroke in 3 African countries (Nigeria, Kenya, and South Africa) demonstrated that physiological profiling using plasma renin activity and aldosterone to individualize selection of antihypertensive medications compared with usual care resulted in better blood pressure control with fewer medications over 12 months. Among Ghanaian ischemic stroke survivors treated without renin-aldosterone profiling data, an analysis revealed that those with low renin phenotypes did not achieve any meaningful reduction in blood pressure over 12 months on 3-4 antihypertensive medications despite excellent adherence. For a polygenic condition such as hypertension, individualized therapy based on plasma renin-aldosterone-guided selection of therapy for uncontrolled BP following precision medicine principles may be a viable strategy for primary and secondary stroke prevention with the potential to reduce disparities in the poor outcomes of stroke disproportionately shared by individuals of African ancestry. A dedicated clinical trial to test this hypothesis is warranted.

Medical Management of Patients With Heart Failure and Reduced Ejection Fraction

The options for treating heart failure with reduced ejection fraction (HFrEF) have expanded considerably over the past decade. While neurohormonal modulation using angiotensin converting enzyme inhibitors and angiotensin receptor blockers, beta blockers and mineralocorticoid receptor antagonists remain the cornerstone of therapy, additional novel approaches including angiotensin receptor neprilysin inhibitors, sodium glucose cotransporter 2 inhibitors, ivrabradine, vericiguat and omecamtiv mecarbil have been shown to improve outcomes in patients with HFrEF. This reviews summarizes currently available approaches as well as promising additional strategies that may be used in the future.

Treatment options for patients with heart failure (HF) with reduced ejection fraction (HFrEF) have expanded considerably over the past few decades. Whereas neurohormonal modulation remains central to the management of patients with HFrEF, other pathways have been targeted with drugs that have novel mechanisms of action. The angiotensin receptor-neprilysin inhibitors (ARNIs) which enhance levels of compensatory molecules such as the natriuretic peptides while simultaneously providing angiotensin receptor blockade have emerged as the preferred strategy for inhibiting the renin angiotensin system. Sodium glucose cotransporter 2 (SGLT2) inhibitors which were developed as hypoglycemic agents have been shown to improve outcomes in patients with HF regardless of their diabetic status. These agents along with beta blockers and mineralocorticoid receptor antagonists are the core medical therapies for patients with HFrEF. Additional approaches using ivabradine to slow heart rate in patients with sinus rhythm, the hydralazine/isosorbide dinitrate combination to unload the heart, digoxin to provide inotropic support and vericiguat to augment cyclic guanosine monophosphate production have been shown in well-designed trials to have beneficial effects in the HFrEF population and are used as adjuncts to the core therapies in selected patients. This review provides an overview of the medical management of patients with HFrEF with focus on the major developments that have taken place in the field. It offers prospective of how these drugs should be employed in clinical practice and also a glimpse into some strategies that may prove to be useful in the future.

Prospective clinical trial evaluating spironolactone in Doberman pinschers with congestive heart failure due to dilated cardiomyopathy

INTRODUCTION/OBJECTIVES

Whether the aldosterone antagonist spironolactone has beneficial survival effects in dogs with dilated cardiomyopathy (DCM) is not known. The primary objective of the study was to evaluate the effect of spironolactone, when added to conventional therapy, on survival time in Doberman pinschers with congestive heart failure (CHF) due to DCM.

ANIMALS

Sixty-seven client-owned Doberman pinschers with CHF due to DCM.

MATERIALS AND METHODS

The trial design was prospective, randomized, blinded, and placebo controlled. Dogs were randomized to receive 50-75 mg of spironolactone twice daily (n = 34) or a placebo (n = 33), in addition to standard CHF therapy. Follow-up visits were targeted every 1-6 weeks until endpoint. Quality-of-life questionnaire and physical examination were performed at every visit, while renal biochemistry, ECG, echocardiography, and thoracic radiography were reassessed as needed. The primary endpoint was time to cardiac death, defined as death or euthanasia from CHF or sudden death.

RESULTS

Median time to primary endpoint in the spironolactone group (183 days) was not statistically significantly different than that for the placebo group (124 days) (p = 0.254). The development of atrial fibrillation (AF) was significantly less frequent in the spironolactone group (n = 7) than the placebo group (n = 15, p = 0.037).

CONCLUSIONS

While median time to cardiac death in the spironolactone group was not statistically significantly different than that in the placebo group, adding spironolactone to conventional therapy resulted in reduced occurrence of AF.

Nonsteroidal Mineralocorticoid Receptor Antagonists: Exploring Role in Cardiovascular Disease

ABSTRACT

Aldosterone, a mineralocorticoid hormone, plays a role in the pathophysiology of many cardiovascular disease states. Mineralocorticoid receptor antagonists (MRAs) have been shown to improve clinical outcomes in select patient populations. However, use of available steroidal receptor antagonists, eplerenone and spironolactone, is often limited by the risk or development of hyperkalemia. Nonsteroidal MRAs have been designed to overcome this limitation. The nonsteroidal MRAs have been studied in patients with heart failure with reduced ejection fraction, hypertension, and to lower the risk of cardiac and renal outcomes in those with type 2 diabetes and renal disease. In this review, the pharmacology of the MRAs is compared, the data evaluating the use of nonsteroidal MRAs are examined, and the place of this new generation of therapy is discussed. At this time, it seems that there could be a future role for nonsteroidal MRAs to reduce the risk of renal outcomes in high-risk individuals.

The serum angiotensin-converting enzyme 2 and angiotensin-(1-7) concentrations after optimal therapy for acute decompensated heart failure with reduced ejection fraction

Objective: Elucidation of the role of angiotensin-converting enzyme (ACE) 2 (ACE2)/angiotensin (Ang)-(1-7)/Mas receptor axis in heart failure is necessary. No previous study has reported serial changes in ACE2 and Ang-(1-7) concentrations after optimal therapy (OT) in acute heart failure (AHF) patients. We aimed to investigate serial changes in serum ACE2 and Ang-(1-7) concentrations after OT in AHF patients with reduced ejection fraction (EF).

Methods: ACE2 and Ang-(1-7) concentrations were measured in 68 AHF patients with reduced EF immediately after admission and 1 and 3 months after OT. These parameters were compared with the healthy individuals at three time points.

Results: In the acute phase, Ang-(1-7) and ACE2 concentrations was statistically significantly lower and higher in AHF patients than the healthy individuals (2.40 ± 1.11 vs. 3.1 ± 1.1 ng/ml, P<0.005 and 7.45 ± 3.13 vs. 4.84 ± 2.25 ng/ml, P<0.005), respectively. At 1 month after OT, Ang-(1-7) concentration remained lower in AHF patients than the healthy individuals (2.37 ± 1.63 vs. 3.1 ± 1.1 ng/ml, P<0.05); however, there was no statistically significant difference in ACE2 concentration between AHF patients and the healthy individuals. At 3 months after OT, there were no statistically significant differences in Ang-(1-7) and ACE2 concentrations between AHF patients and the healthy individuals.

Conclusion: ACE2 concentration was equivalent between AHF patients and the healthy individuals at 1 and 3 months after OT, and Ang-(1-7) concentration was equivalent at 3 months after OT.

Effect of high-dose mineralocorticoid receptor antagonist eplerenone on urinary albumin excretion in patients with type 2 diabetes and high cardiovascular risk: Data from the MIRAD trial

AIM

As mineralocorticoid receptor antagonists (MRAs) may possess renoprotective effects in type 2 diabetes (T2D), it was decided to investigate the impact of high-dose MRA on prespecified secondary endpoints-namely, change in urinary albumin-creatinine ratio (UACR) and 24-h ambulatory blood pressure-in the MIRAD trial.

METHODS

This was a double-blind clinical trial in which T2D patients at high risk of or with established cardiovascular disease (CVD) were randomized to either high-dose (100-200 mg) eplerenone or a dose-matched placebo as an add-on to background antihypertensive treatment for 26 weeks. Safety was evaluated by the incidence of hyperkalaemia and kidney-related adverse events.

RESULTS

A total of 140 patients were enrolled (70 in each group). Baseline UACR was 17 mg/g (geometric mean; 95% CI: 13-22); this decreased by 34% in the eplerenone group compared with the placebo group at week 26 (95% CI: -51% to -12%; P =  0.005). There was no significant decrease in 24-h systolic blood pressure (SBP) due to treatment (-3 mmHg; 95% CI: -6 to 1; P = 0.150). However, the observed change in 24-h SBP correlated with the relative change in UACR in the eplerenone group (r = 0.568, P < 0.001). Mean baseline (± SD) estimated glomerular filtration rate (eGFR) was 85 (± 18.6) mL/min/1.73 m², and 12 (± 9%) had an eGFR of 41-59 mL/min/1.73 m². No significant differences in the incidence of mild hyperkalaemia (≥ 5.5 mmol/L; eplerenone vs placebo: 6 vs 2, respectively; P = 0.276) and no severe hyperkalaemia (≥ 6.0 mmol/L) were observed.

CONCLUSION

The addition of high-dose eplerenone to T2D patients at high risk of CVD can markedly reduce UACR with an acceptable safety profile.

Spironolactone in pulmonary arterial hypertension: results of a cross-over study

The renin-angiotensin-aldosterone system is implicated in the pathophysiology of pulmonary arterial hypertension. We undertook this study to determine the effects of spironolactone, a mineralocorticoid receptor blocker, on collagen metabolism in pulmonary arterial hypertension patients. After obtaining institutional review board approval and informed consent, 42 pulmonary arterial hypertension patients were prospectively enrolled and 35 patients completed the 16-week randomized double-blinded crossover clinical trial. Subjects received 50 mg spironolactone or placebo and at the end of week 8, treatment arm was switched. Circulating levels of collagen biomarkers, brain natriuretic peptide, and aldosterone levels were measured, and six-minute walk distance, liver function tests, and echocardiogram data were collected at weeks 0, 8, and 16. Mean age was 45 ± 15 years and 87% were females. At baseline, brain natriuretic peptide and aldosterone levels were 74 ± 95 pg/ml and 7 ± 8 pg/ml, respectively. There was no change in the levels of amino-terminal propeptide of procollagen type III (PIIINP), MMP-9, TIMP-1, and MMP-9/TIMP-1 ratio at weeks 8 and 16 compared to baseline values in placebo arm and treatment arm. The baseline six-min walk distance was 436 ± 115 meters at baseline and no change in walk distance was noted at weeks 8 and 16 (P = 0.372). None of the patients developed hyperkalemia or liver function test abnormalities at weeks 8 and 16 requiring discontinuation of study drug. Our study showed no change in collagen metabolite levels in pulmonary arterial hypertension patients treated with spironolactone. Spironolactone was safe and well tolerated by pulmonary arterial hypertension patients with no increased hyperkalemia or liver function test abnormalities.

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.

Efficacy of low-dose spironolactone on top of angiotensin receptor blockade in patients with glomerulonephritis

Background

Previous studies have shown that aldosterone antagonists have a proteinuria-lowering effect in patients with proteinuria and progressive proteinuric disease not adequately controlled by the use of angiotensin receptor blockers (ARBs). Aldosterone antagonists, in combination with ARBs, might improve proteinuria in patients with glomerulonephritis (GN).

Methods

In the present retrospective study, we evaluated the proteinuria-lowering effect and drug safety of low-dose spironolactone (12.5 mg/day) in 42 patients with GN being treated with an ARB.

Results

Proteinuria decreased from a mean total-protein-to-creatinine (TP/Cr) ratio of 592.3 ± 42.0 mg/g at baseline to 335.6 ± 43.3 mg/g after three months of treatment with spironolactone (P < 0.001). After the initial three months, the mean TP/Cr ratio increased progressively at six, nine, and 12 months; however, it was still less than the baseline value (P = 0.001, < 0.001, and < 0.001, respectively). Although serum Cr levels increased significantly at three and nine months compared with baseline (P = 0.036 and 0.026, respectively), there was no time effect of treatment (P = 0.071). Serum potassium levels tended to increase with time (P = 0.118), whereas systolic and diastolic blood pressures decreased with time (P = 0.122 and 0.044, respectively).

Conclusion

Low-dose spironolactone in combination with an ARB reduced proteinuria in patients with GN, which could represent a novel treatment option in individuals whose proteinuria is not optimally controlled by the use of ARBs alone.

Newer hormonal pharmacotherapies for heart failure

INTRODUCTION

Heart failure (HF) is characterized by maladaptive neurohormonal activation of the cardiovascular and renal systems resulting in circulatory inadequacy and frequent acute exacerbations. The increasing burden of HF prompted investigation of underlying pathophysiological mechanisms and the design of pharmacotherapeutics that would target these pathways.

AREAS COVERED

A MEDLINE search for relevant original investigations and review articles of newer hormonal drugs for HF since the year 2005 till October 2017 provided us with necessary literature. Major trials and relevant clinical investigations were discussed.

EXPERT COMMENTARY

A multitude of hormonal pathways central to HF were identified, including the natriuretic peptide system and neurohormones such as relaxin, arginine vasopressin, and endothelin. However, drugs targeting these novel pathways (aliskiren, tolvaptan, ularitide, serelaxin, bosentan, macitentan) failed to show mortality benefit. This emphasizes a tremendous unmet need in the pharmacotherapy for HF, especially for the subtypes of acute HF and HF with preserved ejection fraction. Sacubitril/valsartan demonstrated substantial mortality benefit in chronic systolic HF population and is endorsed by international HF guidelines. If proven to be efficacious in larger outcome trials, finerenone can be a valuable addition baseline HF therapy. More basic, translational, and phenotype specific clinical research is warranted to improve HF pharmacotherapy.

Effects of calcium channel blockers comparing to angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in patients with hypertension and chronic kidney disease stage 3 to 5 and dialysis: A systematic review and meta-analysis

Background

Calcium channel blocker (CCB) or two renin angiotensin aldosterone system blockades (RAAS), angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), are major potent and prevalently used as initial antihypertensive agents for mild to moderate hypertension, but no uniform agreement as to which antihypertensive drugs should be given for initial therapy, especially among chronic kidney disease (CKD) patients.

Design

A systematic review and meta-analysis comparing CCBs and the two RAAS blockades for hypertensive patients with CKD stage 3 to 5D. The inclusion criteria for this systematic review was RCT that compared the effects of CCBs and the two RAAS blockades in patients with hypertension and CKD. The exclusion criteria were (1) renal transplantation, (2) CKD stage 1 or 2, (3) combined therapy (data cannot be extracted separately). Outcomes were blood pressure change, mortality, heart failure, stroke or cerebrovascular events, and renal outcomes.

Results

21 randomized controlled trials randomized 9,492 patients with hypertensive and CKD into CCBs and the two RAAS blockades treatments. The evidence showed no significant differences in blood presser change, mortality, heart failure, stroke or cerebrovascular events, and renal outcomes between CCBs group and the two RAAS blockades group. The publication bias of pooled mean blood presser change that was detected by Egger’s test was non-significant.

Conclusions

CCBs has similar effects on long term blood pressure, mortality, heart failure, stroke or cerebrovascular events, and renal function to RAAS blockades in patients CKD stage 3 to 5D and hypertension.

Third-generation Mineralocorticoid Receptor Antagonists: Why Do We Need a Fourth?

The first mineralocorticoid receptor (MR) antagonist, spironolactone, was developed almost 60 years ago to treat primary aldosteronism and pathological edema. Its use waned in part because of its lack of selectivity. Subsequently, knowledge of the scope of MR function was expanded along with clinical evidence of the therapeutic importance of MR antagonists to prevent the ravages of inappropriate MR activation. Forty-two years elapsed between the first and MR-selective second generation of MR antagonists. Fifteen years later, despite serious shortcomings of the existing antagonists, a third-generation antagonist has yet to be marketed. Progress has been slowed by the lack of appreciation of the large variety of cell types that express the MR and its diverse cell-type-specific actions, and also its unique complex interaction actions at the molecular level. New MR antagonists should preferentially target the inflammatory and fibrotic effects of MR and perhaps its excitatory effects on sympathetic nervous system, but not the renal tubular epithelium or neurons of the cortex and hippocampus. This review briefly describes efforts to develop a third-generation MR antagonist and why fourth generation antagonists and selective agonists based on structural determinants of tissue and ligand-specific MR activation should be contemplated.

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.

Mineralocorticoid receptor blockade: new insights into the mechanism of action in patients with cardiovascular disease

Mineralocorticoid receptor (MR) blockade is effective in reducing total mortality and the incidence of heart failure in patients with systolic left ventricular dysfunction (SLVD) associated with chronic heart failure or post myocardial infarction.

Pre-clinical and clinical studies in SLVD have shown that MR blockade reduces sudden cardiac death, left ventricular remodelling, left ventricular hypertrophy, endothelial dysfunction, autonomic imbalance, renal dysfunction and improves fibrinolysis.

While MR blockade promotes sodium excretion and the combination of an angiotensin-converting enzyme inhibitor and a MR blocker have been shown to be more effective than either alone in causing natriuresis, it is unlikely that their beneficial effects can be explained solely on this basis.

Aldosterone has been shown to have a number of adverse effects, including activation of other neurohumeral mediators, stimulation of active reactive oxygen species (ROS), activation of the NF-κβ and AP-1 signalling pathways, vascular inflammation and fibrosis, myocardial hypertrophy, autonomic imbalance, and a decrease in fibrinolysis. MR blockade is, however, effective both in situations with and without an increase in serum aldosterone level, since the MR can be occupied and activated by cortisol as well as by aldosterone.

In view of these mechanisms, MR blockade may play an important role not only on SLVD, but also in essential hypertension with normal systolic function, diastolic heart failure, valvular heart disease, vascular stiffening with ageing, progression of renal disease, and diabetes mellitus. This hypothesis will, however, require further prospective evaluation.

The critical role of the central nervous system (pro)renin receptor in regulating systemic blood pressure

The systemic renin-angiotensin system (RAS) has long been recognized as a critically important system in blood pressure (BP) regulation. However, extensive evidence has shown that a majority of RAS components are also present in many tissues and play indispensable roles in BP regulation. Here, we review evidence that RAS components, notably including the newly identified (pro)renin receptor (PRR), are present in the brain and are essential for the central regulation of BP. Binding of the PRR to its ligand, prorenin or renin, increases BP and promotes progression of cardiovascular diseases in an angiotensin II-dependent and -independent manner, establishing the PRR a promising antihypertensive drug target. We also review the existing PRR blockers, including handle region peptide and PRO20, and propose a rationale for blocking prorenin/PRR activation as a therapeutic approach that does not affect the actions of the PRR in vacuolar H(+)-ATPase and development. Finally, we summarize categories of currently available antihypertensive drugs and consider future perspectives.

Refractory hyperaldosteronism in heart failure is associated with plasma renin activity and angiotensinogen polymorphism

AIMS

Refractory hyperaldosteronism is frequently observed in heart failure patients on up-to-date treatment, and holds prognostic value. Our aim was to identify which factors, either genetic or nongenetic, are associated with refractory hyperaldosteronism.

METHODS

We enrolled 109 consecutive patients with left ventricular systolic dysfunction [left ventricular ejection fraction (LVEF) 32 ± 10%; 86% males; age 65 ± 13 years (mean ± standard deviation)] on optimized adrenergic and renin-angiotensin-aldosterone system (RAAS) antagonism, undergoing clinical and neuroendocrine characterization, and genotyping for six polymorphisms in key RAAS-regulating genes [angiotensinogen (AGT M235T), angiotensin-converting enzyme (ACE-240A>T and I/D), angiotensin II type I receptor (AGTR1 1166A>C), aldosterone synthase (CYP11B2-344C>T) and renin (REN rs7539596)].

RESULTS

Patients with refractory hyperaldosteronism (n = 41, 38%, with plasma concentration >180 ng/l, URL, median 283 ng/l, interquartile range 218-433), when compared with those without (106 ng/l, 74-144; P < 0.001), were not different either for treatment or LVEF, while presented with different AGT M235T genotype distribution (P = 0.047). After adjustment for several humoral, instrumental, functional and therapeutical variables, only plasma renin activity (PRA) (P < 0.001) and potassium (P = 0.027) were independently associated with refractory hyperaldosteronism. Among polymorphisms, only AGT M235T (P = 0.038) was associated with refractory hyperaldosteronism, after adjustment for nongenetic variables.

CONCLUSIONS

In conclusion, refractory hyperaldosteronism in heart failure may be influenced by AGT M235T polymorphism, among RAAS candidate genes, and by PRA, which may represent, respectively, a constitutive (genotype dependent) and a nongenetic (phenotype-dependent) trigger for aldosterone elevation.

Finerenone : third-generation mineralocorticoid receptor antagonist for the treatment of heart failure and diabetic kidney disease

INTRODUCTION

The mineralocorticoid receptor antagonists (MRAs) spironolactone and eplerenone reduce the risk of hospitalizations and mortality in patients with heart failure (HF) with reduced ejection fraction (HFrEF), and attenuate progression of diabetic kidney disease. However, their use is limited by the fear of inducing hyperkalemia, especially in patients with renal dysfunction. Finerenone is a novel nonsteroidal MRA, with higher selectivity toward the mineralocorticoid receptor (MR) compared to spironolactone and stronger MR-binding affinity than eplerenone.

AREAS COVERED

This paper discusses the chemistry, pharmacokinetics, clinical efficacy and safety of finerenone.

EXPERT OPINION

The selectivity and greater binding affinity of finerenone to the MR may reduce the risk of hyperkalemia and renal dysfunction and thereby overcome the reluctance to start and uptitrate MRAs in patients with HF and diabetic kidney disease. Studies conducted in patients with HFrEF and moderate chronic kidney disease and diabetic kidney disease, showed promising results. Phase III trials will have to show whether finerenone might become the third-generation MRA for the treatment of HF and diabetic kidney disease.

Outpatient management of chronic heart failure

INTRODUCTION

Heart failure (HF) treatment attracts a share of intensive research because of its poor HF prognosis. In the past decades, the prognosis of HF has improved considerably, mainly as a consequence of the progress that has been made in the pharmacological management of HF.

AREAS COVERED

This article reviews the outpatient pharmacological management of chronic HF due to left ventricular systolic dysfunction and offers recommendations on the use of various drugs. In addition, the present article attempts to provide practical therapeutic algorithms based on current clinical strategies.

EXPERT OPINION

Continued research directed toward identifying factors associated with high pharmacotherapy guideline adherence and understanding of variants that influence response to drugs will hopefully halt or reverse the major pathophysiological mechanisms involved in this syndrome.

Biomarkers of activation of renin-angiotensin-aldosterone system in heart failure: how useful, how feasible?

Renin-angiotensin-aldosterone system (RAAS), participated by kidney, liver, vascular endothelium, and adrenal cortex, and counter-regulated by cardiac endocrine function, is a complex endocrine system regulating systemic functions, such as body salt and water homeostasis and vasomotion, in order to allow the accomplishment of physiological tasks, such as orthostasis, physical and emotional stimuli, and to react towards the hemorrhagic insult, in tight conjunction with other neurohormonal axes, namely the sympathetic nervous system, the endothelin and vasopressin systems. The systemic as well as the tissue RAAS are also dedicated to promote tissue remodeling, particularly relevant after damage, when chronic activation may configure as a maladaptive response, leading to fibrosis, hypertrophy and apoptosis, and organ dysfunction. RAAS activation is a fingerprint of systemic arterial hypertension, kidney dysfunction, vascular atherosclerotic disease, and is definitely an hallmark of heart failure, which rapidly shifts from organ disease to a disorder of neurohormonal regulatory systems. Chronic RAAS activation is an indirect or direct target of most effective pharmacological treatments in heart failure, such as beta-blockers, inhibitors of angiotensin converting enzyme, angiotensin receptor blockers, direct renin inhibitors, and mineralocorticoid receptor blockers. Biomarkers of RAAS activation are available, with different feasibility and accuracy, such as plasma renin activity, renin, angiotensin II, and aldosterone, which all accompany the increasing clinical severity of heart failure disease, and are well recognized prognostic factors, even in patients with optimal therapy. Polymorphisms influencing the expression and activity of RAAS pathways have been recognized as clinically relevant biomarkers, likely influencing either the individual clinical phenotype, or the response to drugs. This solid, growing evidence strongly suggests the rationale for the use of biomarkers of the RAAS activation, as a guide to tailor individual therapy in the current practice, and their implementation as a rule-in marker for future trials on novel drugs in the heart failure setting.

Effects of spironolactone on long-term mortality and morbidity in patients with heart failure and mild or no symptoms

BACKGROUND

The purpose of this study is to evaluate long-term effects of spironolactone, an affordable and widely used aldosterone receptor blocker, in patients with heart failure (HF) and mild or no symptoms.

METHODS

The study is a single-blind, placebo-controlled, blinded endpoint, randomized study. Patients with New York Heart Association (NYHA) classes I to II HF and left ventricular ejection fraction < 40% were randomized to spironolactone or placebo in addition to optimal therapy. The primary endpoint was the composite of death from any cause or cardiovascular hospitalization.

RESULTS

A total of 130 patients were randomized to spironolactone (n = 65) or placebo (n = 65). Patients on spironolactone had a better event-free survival for cardiovascular death or cardiovascular hospitalizations and for cardiovascular hospitalizations alone. At multivariable analysis, only spironolactone therapy, left ventricular ejection fraction and serum creatinine levels had an independent prognostic value for the combined endpoint, whereas only spironolactone therapy and serum creatinine levels had an independent prognostic value for cardiovascular hospitalizations alone.

CONCLUSIONS

Administration of spironolactone reduced the composite of death and cardiovascular hospitalization in patients with NYHA classes I to II HF. These results suggest that spironolactone could be beneficial when administered on top of optimal therapy among patients with HF and mild or no symptoms.

Aldosterone blockade in chronic kidney disease

Although blockade of the renin-angiotensin-aldosterone system with angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers has become standard therapy for chronic kidney disease (CKD), renewed interest in the role of aldosterone in mediating the injuries and progressive insults of CKD has highlighted the potential role of treatments targeting the mineralocorticoid receptor (MR). Although salt restriction is an important component of mitigating the profibrotic effects of MR activation, a growing body of literature has shown that MR antagonists, spironolactone and eplerenone, can reduce proteinuria and blood pressure in patients at all stages of CKD. These agents carry a risk of hyperkalemia, but this risk likely can be predicted based on baseline renal function and mitigated using dietary modifications and adjustments of concomitant medications. Data on hard outcomes, such as progression to end-stage renal disease and overall mortality, still are lacking in patients with CKD.

Mineralocorticoid receptor blockade in addition to angiotensin converting enzyme inhibitor or angiotensin II receptor blocker treatment: an emerging paradigm in diabetic nephropathy: a systematic review

Blockade of the renin-angiotensin-aldosterone system (RAAS) is a standard therapeutic intervention in diabetic patients with chronic kidney disease (CKD). Concomitant mineralocorticoid receptor blockade has been studied as a novel approach to further slow down CKD progression. We used PubMed and EMBASE databases to search for relevant literature. We included in our review eight studies in patients of at least 18 years of age, with a diagnosis of type 1 or type 2 diabetes mellitus and diabetic nephropathy, under an angiotensin converting enzyme inhibitor (ACEI) and/or an angiotensin II receptor blocker (ARB) as standard treatment. A subset of patients in each study also received a mineralocorticoid receptor blocker (MRB) (either spironolactone or eplerenone) in addition to standard treatment. Combined treatment with a mineralocorticoid receptor blocker further reduced albuminuria by 23 to 61% compared with standard treatment. Estimated glomerular filtration rate values upon study completion slightly decreased under combined treatment. Blood pressure levels upon study completion were significantly lower with combined treatment in three studies. Hyperkalemia prevalence increased in patients under combined treatment raising dropout rate up to 17%. Therefore, combined treatment by an ACEI/ARB and a MRB may further decrease albuminuria in diabetic nephropathy. This effect may be due to the specific properties of the MRB treatment. Clinicians should regularly check potassium levels because of the increased risk of hyperkalemia. Available evidence should be confirmed by an adequately powered comparative trial of the standard treatment (ACEI or ARB) versus combined treatment by an ACEI/ARB and a MRB.

AT1 receptor blockade for the prevention of cardiovascular events after myocardial infarction

Myocardial infarction is associated with high morbidity and mortality. Multiple therapeutic modalities have been shown to be effective in reducing adverse postmyocardial infarction outcomes. The most prominent drugs that have been used in this group of patients are those that oppose the effects of the renin-angiotensin-aldosterone system. These drugs include beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers and aldosterone blockers. Following initial success with angiotensin-converting enzyme inhibitors in reducing mortality and cardiac remodeling in postmyocardial infarction patients, recent focus has been on adjunctive or alternative use of angiotensin II-receptor antagonists. Multiple large-scale, randomized trials have been conducted in order to compare angiotensin II-receptor antagonists with a combination of angiotensin II-receptor antagonists and angiotensin-converting enzyme inhibitors, and with angiotensin-converting enzyme inhibitors alone in postmyocardial infarction patients and also in heart failure. Although some results are conflicting, the weight of evidence is towards equivalency of these two groups of medicines, provided that the maximum effective dose of the angiotensin II-receptor antagonists is used. The combination of an angiotensin-converting enzyme inhibitor and an angiotensin II-receptor antagonist may have additional benefits for some, but not all, patients; for example, reducing morbidity and mortality in patients with chronic heart failure but not in postmyocardial infarction patients. Indeed, in the postmyocardial infarction setting, the combination appears simply to increase the side effects, without conferring additional benefits. Use of aldosterone antagonists as adjunctive therapy in postmyocardial infarction patients is associated with added benefits in terms of mortality reduction and will become the standard of care in this group of patients.

PF-03882845, a non-steroidal mineralocorticoid receptor antagonist, prevents renal injury with reduced risk of hyperkalemia in an animal model of nephropathy

The mineralocorticoid receptor (MR) antagonists PF-03882845 and eplerenone were evaluated for renal protection against aldosterone-mediated renal disease in uninephrectomized Sprague-Dawley (SD) rats maintained on a high salt diet and receiving aldosterone by osmotic mini-pump for 27 days. Serum K(+) and the urinary albumin to creatinine ratio (UACR) were assessed following 14 and 27 days of treatment. Aldosterone induced renal fibrosis as evidenced by increases in UACR, collagen IV staining in kidney cortex, and expression of pro-fibrotic genes relative to sham-operated controls not receiving aldosterone. While both PF-03882845 and eplerenone elevated serum K(+) levels with similar potencies, PF-03882845 was more potent than eplerenone in suppressing the rise in UACR. PF-03882845 prevented the increase in collagen IV staining at 5, 15 and 50 mg/kg BID while eplerenone was effective only at the highest dose tested (450 mg/kg BID). All doses of PF-03882845 suppressed aldosterone-induced increases in collagen IV, transforming growth factor-β 1 (Tgf-β 1), interleukin-6 (Il-6), intermolecular adhesion molecule-1 (Icam-1) and osteopontin gene expression in kidney while eplerenone was only effective at the highest dose. The therapeutic index (TI), calculated as the ratio of the EC50 for increasing serum K(+) to the EC50 for UACR lowering, was 83.8 for PF-03882845 and 1.47 for eplerenone. Thus, the TI of PF-03882845 against hyperkalemia was 57-fold superior to that of eplerenone indicating that PF-03882845 may present significantly less risk for hyperkalemia compared to eplerenone.

Aldosterone receptor antagonists: current perspectives and therapies

Aldosterone is a downstream effector of angiotensin II in the renin-angiotensin-aldosterone system and binds to the mineralocorticoid receptor. The classical view of aldosterone primarily acting at the level of the kidneys to regulate plasma potassium and intravascular volume status is being supplemented by evidence of new "off-target" effects of aldosterone in other organ systems. The genomic effects of aldosterone are well known, but there is also evidence for non-genomic effects and these recently identified effects of aldosterone have required a revision in the traditional view of aldosterone's role in human health and disease. The aim of this article is to review the biological action of aldosterone and the mineralocorticoid receptor leading to subsequent physiologic and pathophysiologic effects involving the vasculature, central nervous system, heart, and kidneys. Furthermore, we outline current evidence evaluating the use of mineralocorticoid receptor antagonists in the treatment of primary aldosteronism, primary hypertension, resistant hypertension, obstructive sleep apnea, heart failure, and chronic kidney disease.

The ubiquitous mineralocorticoid receptor: clinical implications

Mineralocorticoid receptors (MR) exist in many tissues, in which they mediate diverse functions crucial to normal physiology, including tissue repair and electrolyte and fluid homeostasis. However, inappropriate activation of MR within these tissues, and especially in the brain, causes hypertension and pathological vascular, cardiac, and renal remodeling. MR binds aldosterone, cortisol and corticosterone with equal affinity. In aldosterone-target cells, co-expression with the 11β-hydroxysteroid dehydrogenase 2 (HSD2) allows aldosterone specifically to activate MR. Aldosterone levels are excessive in primary aldosteronism, but in conditions with increased oxidative stress, like CHF, obesity and diabetes, MR may also be inappropriately activated by glucocorticoids. Unlike thiazide diuretics, MR antagonists are diuretics that do not cause insulin resistance. Addition of MR antagonists to standard treatment for hypertension and cardiac or renal disease decreases end-organ pathology and sympathetic nerve activation (SNA), and increases quality of life indices.

Importance of the time of initiation of mineralocorticoid receptor antagonists on risk of mortality in patients with heart failure

INTRODUCTION

Several studies have definitively shown the benefit of mineralocorticoid receptor antagonists (MRAs) in patients with heart failure (HF). However, very few prior studies examined the relationship between the timing of initiation of MRAs and prognosis. In addition, on this topic, there is no information regarding the specific population of patients suffering a first episode of decompensated congestive HF.

METHODS

We studied a homogenous cohort of patients discharged alive from our hospital after a first episode of decompensated congestive HF, in order to clarify the association between time of aldosterone receptor antagonist (ARA) initiation (within the first 90 days after hospital discharge) and mortality. Our population was composed of a series of consecutive patients. All-cause mortality was compared between patients who initiated MRAs at discharge (early group) and those who initiated MRAs one month later and up to 90 days after discharge (delayed group). We used prescription time distribution matching to control for survival difference between groups.

RESULTS

The early and delayed groups consisted of 365 and 320 patients, respectively. During the one-year follow-up, a significant difference in mortality was demonstrated between groups. Adjusted hazard ratios (HRs) for early versus delayed initiation were 1.72 (95% confidence interval (CI) 0.96 to 2.84) at six months, and 1.93 (95% CI 1.18 to 3.14) at one year.

CONCLUSIONS

Delay of MRA initiation up to 30 to 90 days after discharge implies a significant increase in mortality compared with MRA initiation at discharge, after a first episode of decompensate congestive HF.

Cardiovascular effects of Tulbaghia violacea Harv. (Alliaceae) root methanolic extract in Dahl salt-sensitive (DSS) rats

ETHNOPHARMACOLOGICAL RELEVANCE

In African folk medicine, Tulbaghia violacea Harv.(Alliaceae), a herbaceous plant also known by other common local names such as 'wild garlic', 'society garlic' and 'sweet garlic', has been used for the management, control and/or treatment of several human ailments; including hypertension. The aim of the present study was to investigate the cardiovascular effects of methanolic extract of Tulbaghia violacea Harv. in Dahl salt-sensitive (DSS) rats.

MATERIALS AND METHODS

DSS rats were treated intraperitoneally (i.p) as follows: distilled water, control (CON) (3 ml/kg/b.w.); captopril (CAP) (25 mg/kg/b.w.); or methanolic extract of Tulbaghia violacea (TVL) (50 mg/kg/b.w.) for 7 weeks. Systolic blood pressure (SBP) was measured bi-weekly whilst 24-hour urine volumes and sodium concentrations were assessed weekly. Animals were sacrificed on day 49 by halothane overdose. Blood was removed for the determination of aldosterone concentration and angiotensin converting enzyme (ACE) activity. Left kidney was harvested for angiotensin Ia (AT1a) receptor gene expression.

RESULTS

CON showed a significant percentage increase in SBP (mmHg) on day 49 compared to day 0 (baseline values) (9.75±1.7% vs. 2.33±0.77%; p<0.05). CAP and TVL showed significant percentage decreases in SBP at week 7 when compared to baseline (8.13±1.23% and12.88±3.12% p<0.01). Urine volumes (ml) increased significantly in CAP from week 1 to week 4 (9.63±2.22 vs.10.97±1.75 p<0.05) and in TVL from week 2 to 7 (9.23±0.91 vs. 11.90±1.17 p<0.05). Urinary sodium concentration (mmol/L/24 h urine samples) was significantly higher in CAP (0.72±0.07 vs.1.31±0.03 p<0.05) and in TVL (0.71±0.09 vs. 1.68±0.16; p<0.05) at week 7 compared to baseline levels. There was no significant difference in the plasma aldosterone levels (pmol/L) of all the three groups. Serum ACE (U/L) activity was significantly higher in CAP compared to CON and TVL (277.0±11.6 vs. 121.5±3.93; and 147.0±6.63; p<0.05 respectively). CAP showed a significant 6.4 fold increase in AT1a mRNA expression vs. CON (p<0.05) and a 4.5 fold increase vs. TVL (p<0.05). There was no significant difference between CON and TVL treated rats. CAP and TVL showed no significant change in the expression of AT2.

CONCLUSION

This study showed that TVL possesses antihypertensive effect in Dahl salt-sensitive rats when administered over a long-term.

Effects of mineralocorticoid receptor antagonists on the risk of sudden cardiac death in patients with left ventricular systolic dysfunction: a meta-analysis of randomized controlled trials

BACKGROUND

Sudden cardiac death (SCD) is an important cause of death in patients with left ventricular systolic dysfunction. Mineralocorticoid receptor antagonists (MRAs) may attenuate this risk. The objective of this meta-analysis was to assess the impact of MRAs on SCD in patients with left ventricular systolic dysfunction.

METHODS AND RESULTS

We systematically searched PubMed, EMBASE, Cochrane, and other databases through March 30, 2012, without language restrictions. We included trials that enrolled patients with left ventricular ejection fraction of ≤45%, randomized subjects to MRAs versus control and reported outcomes on SCD, total and cardiovascular mortality. Eight published trials that enrolled 11 875 patients met inclusion criteria. Of these, 6 reported data on SCD and cardiovascular mortality, and 7 reported data on total mortality. No heterogeneity was observed among the trials. Patients treated with MRAs had 23% lower odds of experiencing SCD compared with controls (odds ratio, 0.77; 95% confidence interval, 0.66-0.89; P=0.001). Similar reductions were observed in cardiovascular (0.75; 95% confidence interval, 0.68-0.84; P<0.001) and total mortality (odds ratio, 0.74; 95% confidence interval, 0.63-0.86; P<0.001). Although publication bias was observed, the results did not change after a trim and fill test, suggesting that the impact of this bias was likely insignificant.

CONCLUSIONS

MRAs reduce the risk of SCD in patients with left ventricular systolic dysfunction. Comparative effectiveness studies of MRAs on SCD in usual care as well as studies evaluating the efficacy of other therapies to prevent SCD in patients receiving optimal MRA therapy are needed to guide clinical decision-making.

The effect of angiotensin-converting enzyme inhibitor use on bone loss in elderly Chinese

In this study we analyzed the independent effect of angiotensin-converting enzyme (ACE) inhibitor use on bone loss in elderly Chinese. The subjects were from two cohort studies which investigated the risk factors of osteoporotic fractures in Hong Kong-dwelling elderly Chinese. A total of 2161 subjects (1280 male, 881 female) were selected for this analysis. The results showed that unadjusted annualized percentage bone loss of male ACE inhibitor users was not different from non-users; however, female ACE inhibitor users had significantly greater bone loss both in total hip and femoral neck than non-users. After adjusting for significant confounders, female continuous ACE inhibitor users had significantly greater bone loss at total hip and femoral neck. In conclusion, continuous use of ACE inhibitors over 4 years was associated with increased bone loss in total hip and femoral neck in older Chinese women.

Inhibition of the renin-angiotensin-aldosterone system: is there room for dual blockade in the cardiorenal continuum?

Antagonism of renin-angiotensin-aldosterone system is exerted through angiotensin-converting enzyme inhibitors, angiotensin receptor antagonists, renin inhibitors and mineralocorticoid receptor antagonists. These drugs have been successfully tested in numerous trials and in different clinical settings. The original indications of renin-angiotensin-aldosterone system blockers have progressively expanded from the advanced stages to the earlier stages of cardiorenal continuum. To optimize the degree of blockade of renin-angiotensin-aldosterone system, dose uptitrations of angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists or the use of a dual blockade, initially identified with the combination of angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists, have been proposed. The data from the Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial (ONTARGET) study do not support this specific dual blockade approach. However, the dual blockade of angiotensin-converting enzyme inhibitors/angiotensin receptor antagonists with direct renin inhibitors is currently under investigation while that based on an aldosterone blocker with any of the previous three drugs requires more evidence beyond heart failure. In this review, we revisited potential advantages of dual blockade of renin-angiotensin-aldosterone system in arterial hypertension and diabetes.

Aldosterone, oxidative stress, and NF-κB activation in hypertension-related cardiovascular and renal diseases

The mineralocorticoid aldosterone regulates electrolyte and fluid balance and is involved in blood pressure homoeostasis. Classically, it binds to its intracellular mineralocorticoid receptor to induce expression of proteins influencing the reabsorption of sodium and water in the distal nephron. Aldosterone gained special attention when large clinical studies showed that blocking its receptor in patients with cardiovascular diseases reduced their mortality. These patients present increased plasma aldosterone levels. The exact mechanisms of the potential toxic effects of aldosterone leading to cardiovascular damage are not known yet. The observation of reduced nitric oxide bioavailability in hyperaldosteronism implied the generation of oxidative stress by aldosterone. Subsequent studies confirmed the increase of oxidative stress markers in patients with chronic heart failure and in animal models of hyperaldosteronism. The effects of reactive oxygen species have been related to the activation of transcription factors, such as NF-κB. This review summarizes the present-day knowledge of aldosterone-induced oxidative stress and NF-κB activation in humans and different experimental models.

Effect of eplerenone, a selective aldosterone blocker, on the development of diabetic nephropathy in type 2 diabetic rats

BACKGROUND

Aldosterone antagonists are reported to have beneficial effects on diabetic nephropathy by effective blocking of the renin-angiotensin-aldosterone system. We investigated the renoprotective effect of the selective aldosterone receptor blocker eplerenone, the angiotensin converting enzyme inhibitor lisinopril, and combined eplerenone and lisinopril treatment in type 2 diabetic rats.

METHODS

ANIMALS WERE DIVIDED INTO SIX GROUPS AS FOLLOWS: Otsuka Long-Evans Tokushima Fatty (OLETF) rat control, OLETF rats treated with a low dose of eplerenone (50 mg/kg/day), OLETF rats treated with a high dose of eplerenone (200 mg/kg/day), OLETF rats treated with lisinopril (10 mg/kg/day), OLETF rats treated with a combination of both drugs (eplerenone 200 mg/kg/day and lisinopril 10 mg/kg/day), and obese non-diabetic Long-Evans Tokushima Otsuka rats for 26 weeks.

RESULTS

Urinary albumin excretion was significantly lower in the lisinopril group, but not in the eplerenone group. Urinary albumin excretion was decreased in the combination group than in the lisinopril group. Glomerulosclerosis and renal expression of type I and type IV collagen, plasminogen activator inhibitor-1, transforming growth factor-β1, connective tissue growth factor, and fibronectin mRNA were markedly decreased in the lisinopril, eplerenone, and combination groups.

CONCLUSION

Eplerenone and lisinopril combination showed additional benefits on type 2 diabetic nephropathy compared to monotherapy of each drug.

Aldosterone, mineralocorticoid receptor, and heart failure

Several large clinical studies have demonstrated the important benefit of mineralocorticoid receptor (MR) antagonists in patients with heart failure, left ventricular dysfunction after myocardial infarction, hypertension or diabetic nephropathy. Aldosterone adjusts the hydro-mineral balance in the body, and thus participates decisively to the control of blood pressure. This traditional view of the action of aldosterone restricted to sodium reabsorption in epithelial tissues must be revisited. Clinical and experimental studies indicated that chronic activation of the MR in target tissues induces structural and functional changes in the heart, kidneys and blood vessels. These deleterious effects include cardiac and renal fibrosis, inflammation and vascular remodeling. It is important to underscore that these effects are due to elevated MR activation that is inadequate for the body salt requirements. Aldosterone is generally considered as the main ligand of MR. However, this is a matter of debate especially in heart. Complexity arises from the glucocorticoids with circulating concentrations much higher than those of aldosterone, and the fact that the MR has a high affinity for 11β-hydroxyglucocorticoids. Nevertheless, the beneficial effects of MR inhibition in patients with heart failure emphasize the importance of this receptor in cardiovascular tissue. Diverse experimental models and strains of transgenic mice have allowed to dissect the effects of aldosterone and the MR in the heart. Taken together experimental and clinical data clearly highlight the deleterious cardiovascular effects of MR stimulation.

Anabolic steroid associated to physical training induces deleterious cardiac effects

PURPOSE

Cardiac aldosterone might be involved in the deleterious effects of nandrolone decanoate (ND) on the heart. Therefore, we investigated the involvement of cardiac aldosterone, by the pharmacological block of AT1 or mineralocorticoid receptors, on cardiac hypertrophy and fibrosis.

METHODS

Male Wistar rats were randomized into eight groups (n = 14 per group): Control (C), nandrolone decanoate (ND), trained (T), trained ND (TND), ND + losartan (ND + L), trained ND + losartan (TND + L), ND + spironolactone (ND + S), and trained ND + spironolactone (TND + S). ND (10 mg·kg(-1)·wk(-1)) was administered during 10 wk of swimming training (five times per week). Losartan (20 mg·kg(-1)·d(-1)) and spironolactone (10 mg·kg(-1)·d(-1)) were administered in drinking water.

RESULTS

Cardiac hypertrophy was increased 10% by using ND and 17% by ND plus training (P < 0.05). In both groups, there was an increase in the collagen volumetric fraction (CVF) and cardiac collagen type III expression (P < 0.05). The ND treatment increased left ventricle-angiotensin-converting enzyme I activity, AT1 receptor expression, aldosterone synthase (CYP11B2), and 11-β hydroxysteroid dehydrogenase 2 (11β-HSD2) gene expression and inflammatory markers, TGFβ and osteopontin. Both losartan and spironolactone inhibited the increase of CVF and collagen type III. In addition, both treatments inhibited the increase in left ventricle-angiotensin-converting enzyme I activity, CYP11B2, 11β-HSD2, TGFβ, and osteopontin induced by the ND treatment.

CONCLUSIONS

We believe this is the first study to show the effects of ND on cardiac aldosterone. Our results suggest that these effects may be associated to TGFβ and osteopontin. Thus, we conclude that the cardiac aldosterone has an important role on the deleterious effects on the heart induced by ND.

Suppression of aldosterone mediates regression of left ventricular hypertrophy in patients with hypertension

Background: High circulating aldosterone levels stimulate myocardial fibrosis and left ventricular hypertrophy (LVH). However, it is not clear whether suppression of aldosterone directly contributes to LVH regression in hypertensive patients.

Methods: The Aliskiren in Left Ventricular Hypertrophy (ALLAY) trial randomised 465 hypertensive overweight subjects with LVH to the direct renin inhibitor aliskiren 300 mg, losartan 100 mg or the combination and followed patients for 9 months. All patients were treated to standard blood pressure targets. Left ventricular (LV) mass index (LVMI) and LV wall thickness (LVWT) were assessed by cardiac magnetic resonance. A subset of 136 patients who had plasma aldosterone concentration (ALDO) measured at baseline and study end was analysed.

Results: At baseline, plasma ALDO was modestly related to systolic blood pressure, LVMI, and wall thickness (all, p < 0.05). Aliskiren, either alone or in combination, was associated with a significantly greater reduction from baseline to 9 months in plasma aldosterone than losartan alone ( p < 0.02). Reduction in ALDO was related to reduction in LVMI even after adjustment for baseline ALDO, BP reduction and treatment group ( p for trend = 0.042).

Conclusion: In hypertensive patients with increased LVWT, aliskiren alone or in combination with the angiotensin receptor blocker losartan provides greater reduction in aldosterone compared to losartan alone. Moreover, suppression of aldosterone was associated with reduction of LVH, independently of the change in SBP, suggesting that suppression of aldosterone, a known mediator of LVH, may be particularly important for LVH regression and as a target for therapy.

Effect of spironolactone on left ventricular ejection fraction and volumes in patients with class I or II heart failure

The beneficial effects of spironolactone in chronic heart failure (HF) have been demonstrated in patients with New York Heart Association (NYHA) class III to IV HF. This study examined the effect of spironolactone on left ventricular (LV) function and functional capacity of patients with mild to moderate HF (NYHA class I to II). One hundred sixty-eight patients with NYHA class I to II HF and LV ejection fraction ≤40% were randomized to spironolactone or placebo and assessed by echocardiography, gated single-photon emission computed tomography, technetium-99m sestamibi single-photon emission computed tomographic radionuclide ventriculography, and cardiopulmonary exercise testing at baseline and after 6 months of treatment. In the spironolactone group LV ejection fraction increased from 35.2 ± 0.7% to 39.1 ± 3.5% (p <0.001), with a decrease in LV end-diastolic and end-systolic volumes and myocardial mass and an improvement in LV diastolic filling pattern. Cardiopulmonary exercise testing parameters did not change. In conclusion, administration of spironolactone to patients with NYHA class I to II HF has beneficial effects on LV remodeling and diastolic function.