Induction of cardiac fibrosis by aldosterone

Blockade of AT1 type receptors for angiotensin II prevents cardiac microvascular fibrosis induced by chronic stress in Sprague-Dawley rats

To test the effects of chronic-stress on the cardiovascular system, the model of chronic mild unpredictable stress (CMS) has been widely used. The CMS protocol consists of the random, intermittent, and unpredictable exposure of laboratory animals to a variety of stressors, during 3 consecutive weeks. In this study, we tested the hypothesis that exposure to the CMS protocol leads to left ventricle microcirculatory remodeling that can be attenuated by angiotensin II receptor blockade. Male Sprague-Dawley rats were randomly assigned into four groups: Control, Stress, Control + losartan, and Stress + losartan (N = 6, each group, losartan: 20 mg/kg/day). The rats were euthanized 15 days after CMS exposure, and blood samples and left ventricle were collected. Rats submitted to CMS presented increased glycemia, corticosterone, noradrenaline and adrenaline concentration, and losartan reduced the concentration of the circulating amines. Cardiac angiotensin II, measured by high-performance liquid chromatography (HPLC), was significantly increased in the CMS group, and losartan treatment reduced it, while angiotensin 1-7 was significantly higher in the CMS losartan-treated group as compared with CMS. Histological analysis, verified by transmission electron microscopy, showed that rats exposed to CMS presented increased perivascular collagen and losartan effectively prevented the development of this process. Hence, CMS induced a state of microvascular disease, with increased perivascular collagen deposition, that may be the trigger for further development of cardiovascular disease. In this case, CMS fibrosis is associated with increased production of catecholamines and with a disruption of renin-angiotensin system balance, which can be prevented by angiotensin II receptor blockade.

Role of the CHADS2 Score in the Evaluation of Carotid Atherosclerosis in Patients with Atrial Fibrillation Undergoing Carotid Artery Ultrasonography

Objective

This study investigated the characteristics of carotid atherosclerosis in patients with atrial fibrillation (AF) and determined the feasibility and significance of the CHADS₂ score in predicting the degree of carotid atherosclerosis.

Methods

Consecutive patients (n = 109) with nonvalvular AF were registered and classified into two groups, the paroxysmal AF group (n = 59) and persistent AF group (n = 50). Fifty healthy patients, matched by sex and age, were considered the control group. All patients were examined using carotid ultrasound and velocity vector imaging (VVI).

Results

Compared with the control group, the mean intimal-medial thickness in the paroxysmal AF group (0.56 ± 0.11 versus 0.61 ± 0.10, respectively, P < 0.05) and the persistent AF group (0.56 ± 0.11 versus 0.64 ± 0.13, respectively, P < 0.001) was significantly increased. The plaque index (PI) in the persistent AF group was significantly higher than that observed in the paroxysmal AF group (1.05 ± 1.33 versus 1.42 ± 1.47, respectively, P < 0.001). Regarding the VVI indices, those reflecting the long-axis longitudinal motion function of carotid arteries were significantly decreased in both AF groups. Compared with the control group, a significantly lower total longitudinal displacement (tLoD) index was observed in the persistent AF group (0.73 ± 0.66 versus 0.31 ± 0.23, respectively, P < 0·0001) and the paroxysmal AF group (0.73 ± 0.66 versus 0.34 ± 0.17, P < 0·0001). The CHADS₂ score was related to indicators reflecting the structure and function of the carotid artery.

Conclusions

Carotid arterial structure and function were significantly altered in patients with AF. The degree of carotid atherosclerosis depended on the duration of AF. The CHADS₂ score may be useful as a predictor of the extent of carotid atherosclerosis in patients with AF.

Cardiac fibrosis: Cell biological mechanisms, molecular pathways and therapeutic opportunities

Cardiac fibrosis is a common pathophysiologic companion of most myocardial diseases, and is associated with systolic and diastolic dysfunction, arrhythmogenesis, and adverse outcome. Because the adult mammalian heart has negligible regenerative capacity, death of a large number of cardiomyocytes results in reparative fibrosis, a process that is critical for preservation of the structural integrity of the infarcted ventricle. On the other hand, pathophysiologic stimuli, such as pressure overload, volume overload, metabolic dysfunction, and aging may cause interstitial and perivascular fibrosis in the absence of infarction. Activated myofibroblasts are the main effector cells in cardiac fibrosis; their expansion following myocardial injury is primarily driven through activation of resident interstitial cell populations. Several other cell types, including cardiomyocytes, endothelial cells, pericytes, macrophages, lymphocytes and mast cells may contribute to the fibrotic process, by producing proteases that participate in matrix metabolism, by secreting fibrogenic mediators and matricellular proteins, or by exerting contact-dependent actions on fibroblast phenotype. The mechanisms of induction of fibrogenic signals are dependent on the type of primary myocardial injury. Activation of neurohumoral pathways stimulates fibroblasts both directly, and through effects on immune cell populations. Cytokines and growth factors, such as Tumor Necrosis Factor-α, Interleukin (IL)-1, IL-10, chemokines, members of the Transforming Growth Factor-β family, IL-11, and Platelet-Derived Growth Factors are secreted in the cardiac interstitium and play distinct roles in activating specific aspects of the fibrotic response. Secreted fibrogenic mediators and matricellular proteins bind to cell surface receptors in fibroblasts, such as cytokine receptors, integrins, syndecans and CD44, and transduce intracellular signaling cascades that regulate genes involved in synthesis, processing and metabolism of the extracellular matrix. Endogenous pathways involved in negative regulation of fibrosis are critical for cardiac repair and may protect the myocardium from excessive fibrogenic responses. Due to the reparative nature of many forms of cardiac fibrosis, targeting fibrotic remodeling following myocardial injury poses major challenges. Development of effective therapies will require careful dissection of the cell biological mechanisms, study of the functional consequences of fibrotic changes on the myocardium, and identification of heart failure patient subsets with overactive fibrotic responses.

Genomic and rapid effects of aldosterone: what we know and do not know thus far

Aldosterone is the most known mineralocorticoid hormone synthesized by the adrenal cortex. The genomic pathway displayed by aldosterone is attributed to the mineralocorticoid receptor (MR) signaling. Even though the rapid effects displayed by aldosterone are long known, our knowledge regarding the receptor responsible for such event is still poor. It is intense that the debate whether the MR or another receptor-the "unknown receptor"-is the receptor responsible for the rapid effects of aldosterone. Recently, G protein-coupled estrogen receptor-1 (GPER-1) was elegantly shown to mediate some aldosterone-induced rapid effects in several tissues, a fact that strongly places GPER-1 as the unknown receptor. It has also been suggested that angiotensin receptor type 1 (AT1) also participates in the aldosterone-induced rapid effects. Despite this open question, the relevance of the beneficial effects of aldosterone is clear in the kidneys, colon, and CNS as aldosterone controls the important water reabsorption process; on the other hand, detrimental effects displayed by aldosterone have been reported in the cardiovascular system and in the kidneys. In this line, the MR antagonists are well-known drugs that display beneficial effects in patients with heart failure and hypertension; it has been proposed that MR antagonists could also play an important role in vascular disease, obesity, obesity-related hypertension, and metabolic syndrome. Taken altogether, our goal here was to (1) bring a historical perspective of both genomic and rapid effects of aldosterone in several tissues, and the receptors and signaling pathways involved in such processes; and (2) critically address the controversial points within the literature as regarding which receptor participates in the rapid pathway display by aldosterone.

Cardiac magnetic resonance imaging of myocardial mass and fibrosis in primary aldosteronism

BACKGROUND

Primary aldosteronism (PA) is associated with increased cardiovascular morbidity, presumably due to left ventricular (LV) hypertrophy and fibrosis. However, the degree of fibrosis has not been extensively studied. Cardiac magnetic resonance imaging (CMR) contrast enhancement and novel sensitive T1 mapping to estimate increased extracellular volume (ECV) are available to measure the extent of fibrosis.

OBJECTIVES

To assess LV mass and fibrosis before and after treatment of PA using CMR with contrast enhancement and T1 mapping.

METHODS

Fifteen patients with newly diagnosed PA (PA1) and 24 age- and sex-matched healthy subjects (HS) were studied by CMR with contrast enhancement. Repeated imaging with a new scanner with T1 mapping was performed in 14 of the PA1 and 20 of the HS median 18 months after specific PA treatment and in additional 16 newly diagnosed PA patients (PA2).

RESULTS

PA1 had higher baseline LV mass index than HS (69 (53-91) vs 51 (40-72) g/m²; P < 0.001), which decreased significantly after treatment (58 (40-86) g/m²; P < 0.001 vs baseline), more with adrenalectomy (n = 8; -9 g/m²; P = 0.003) than with medical treatment (n = 6; -5 g/m²; P = 0.075). No baseline difference was found in contrast enhancement between PA1 and HS. T1 mapping showed no increase in ECV as a myocardial fibrosis marker in PA. Moreover, ECV was lower in the untreated PA2 than HS 10 min post-contrast, and in both PA groups compared with HS 20 min post-contrast.

CONCLUSION

Specific treatment rapidly reduced LV mass in PA. Increased myocardial fibrosis was not found and may not represent a common clinical problem.

Pharmacophore Modeling and in Silico/in Vitro Screening for Human Cytochrome P450 11B1 and Cytochrome P450 11B2 Inhibitors

Cortisol synthase (CYP11B1) is the main enzyme for the endogenous synthesis of cortisol and its inhibition is a potential way for the treatment of diseases associated with increased cortisol levels, such as Cushing's syndrome, metabolic diseases, and delayed wound healing. Aldosterone synthase (CYP11B2) is the key enzyme for aldosterone biosynthesis and its inhibition is a promising approach for the treatment of congestive heart failure, cardiac fibrosis, and certain forms of hypertension. Both CYP11B1 and CYP11B2 are structurally very similar and expressed in the adrenal cortex. To facilitate the identification of novel inhibitors of these enzymes, ligand-based pharmacophore models of CYP11B1 and CYP11B2 inhibition were developed. A virtual screening of the SPECS database was performed with our pharmacophore queries. Biological evaluation of the selected hits lead to the discovery of three potent novel inhibitors of both CYP11B1 and CYP11B2 in the submicromolar range (compounds 8–10), one selective CYP11B1 inhibitor (Compound 11, IC₅₀ = 2.5 μM), and one selective CYP11B2 inhibitor (compound 12, IC₅₀ = 1.1 μM), respectively. The overall success rate of this prospective virtual screening experiment is 20.8% indicating good predictive power of the pharmacophore models.

Heart failure with preserved ejection fraction: current management and future strategies : Expert opinion on the behalf of the Nucleus of the "Heart Failure Working Group" of the German Society of Cardiology (DKG)

About 50% of all patients suffering from heart failure (HF) exhibit a reduced ejection fraction (EF ≤ 40%), termed HFrEF. The others may be classified into HF with midrange EF (HFmrEF 40-50%) or preserved ejection fraction (HFpEF, EF ≥ 50%). Presentation and pathophysiology of HFpEF is heterogeneous and its management remains a challenge since evidence of therapeutic benefits on outcome is scarce. Up to now, there are no therapies improving survival in patients with HFpEF. Thus, the treatment targets symptom relief, quality of life and reduction of cardiac decompensations by controlling fluid retention and managing risk factors and comorbidities. As such, renin-angiotensin-aldosterone inhibitors, diuretics, calcium channel blockers (CBB) and beta-blockers, diet and exercise recommendations are still important in HFpEF, although these interventions are not proven to reduce mortality in large randomized controlled trials. Recently, numerous new treatment targets have been identified, which are further investigated in studies using, e.g. soluble guanylate cyclase stimulators, inorganic nitrates, the angiotensin receptor neprilysin inhibitor LCZ 696, and SGLT2 inhibitors. In addition, several devices such as the CardioMEMS, interatrial septal devices (IASD), cardiac contractility modulation (CCM), renal denervation, and baroreflex activation therapy (BAT) were investigated in different forms of HFpEF populations and some of them have the potency to offer new hopes for patients suffering from HFpEF. On the basic research field side, lot of new disease-modifying strategies are under development including anti-inflammatory drugs, mitochondrial-targeted antioxidants, new anti-fibrotic and microRNA-guided interventions are under investigation and showed already promising results. This review addresses available data of current best clinical practice and management approaches based on expert experiences and summarizes novel approaches towards HFpEF.

Cardiac Fibrosis and Arrhythmogenesis

Myocardial injury, mechanical stress, neurohormonal activation, inflammation, and/or aging all lead to cardiac remodeling, which is responsible for cardiac dysfunction and arrhythmogenesis. Of the key histological components of cardiac remodeling, fibrosis either in the form of interstitial, patchy, or dense scars, constitutes a key histological substrate of arrhythmias. Here we discuss current research findings focusing on the role of fibrosis, in arrhythmogenesis. Numerous studies have convincingly shown that patchy or interstitial fibrosis interferes with myocardial electrophysiology by slowing down action potential propagation, initiating reentry, promoting after-depolarizations, and increasing ectopic automaticity. Meanwhile, there has been increasing appreciation of direct involvement of myofibroblasts, the activated form of fibroblasts, in arrhythmogenesis. Myofibroblasts undergo phenotypic changes with expression of gap-junctions and ion channels thereby forming direct electrical coupling with cardiomyocytes, which potentially results in profound disturbances of electrophysiology. There is strong evidence that systemic and regional inflammatory processes contribute to fibrogenesis (i.e., structural remodeling) and dysfunction of ion channels and Ca2+ homeostasis (i.e., electrical remodeling). Recognizing the pivotal role of fibrosis in the arrhythmogenesis has promoted clinical research on characterizing fibrosis by means of cardiac imaging or fibrosis biomarkers for clinical stratification of patients at higher risk of lethal arrhythmia, as well as preclinical research on the development of antifibrotic therapies. At the end of this review, we discuss remaining key questions in this area and propose new research approaches. © 2017 American Physiological Society. Compr Physiol 7:1009-1049, 2017.

Are two drugs better than one? A review of combination therapies for hypertension

Current guidelines for pharmacotherapy briefly describe a role for combination antihypertensive therapy. However, guidance on whether combination therapy should be used at the time of initiating therapy or as add on, and the choice of combination therapy is scarce. Areas covered: Current literature suggests that intensive blood pressure control is the key to managing cardiovascular risk. Along with lifestyle management, pharmacotherapy is an central component in the treatment of hypertension. Here, we aim to review the pathophysiology of hypertension, rationale for using combination therapy, and the different combinations of antihypertensive drug classes that are available in the market. Papers from 1967 through 2016 listed on PubMed on this topic were reviewed. Expert opinion: Based on the review of the literature, combination antihypertensive therapies are more effective than monotherapy and are also well tolerated, safe and cost effective for treatment of hypertension. Further research is needed to help guide the choice of combination antihypertensive therapy in different patient populations based on age, gender, race and comorbidities.

A novel aldosterone synthase inhibitor ameliorates mortality in pressure-overload mice with heart failure

It has been elucidated that mineralocorticoid receptor antagonists reduce mortality in patients with congestive heart failure and post-acute myocardial infarction. A direct inhibition of aldosterone synthase (CYP11B2) is also expected to have therapeutic benefits equal in quality to mineralocorticoid receptor antagonists in terms of reducing mineralocorticoid receptor signaling. Therefore, we have screened our chemical libraries and identified a novel and potent aldosterone synthase inhibitor, 2,2,2-trifluoro-1-{4-[(4-fluorophenyl)amino]pyrimidin-5-y}-1-[1-(methylsulfonyl)piperidin-4-yl]ethanol (compound 1), by lead optimization. Pharmacological properties of compound 1 were examined in in vitro cell-based assays and an in vivo mouse model of pressure-overload hypertrophy by transverse aortic constriction (TAC). Compound 1 showed potent CYP11B2 inhibition against human and mouse enzymes (IC₅₀; 0.003μM and 0.096μM, respectively) in a cell-based assay. The oral administration of 0.06% compound 1 in the food mixture of a mouse TAC model significantly reduced the plasma aldosterone level and ameliorated mortality rate. This study is the first to demonstrate that a CYP11B2 inhibitor improved survival rates of heart failure induced by pressure-overload in mice. The treatment of 0.06% compound 1 did not elevate plasma potassium level in this model, although further evaluation of hyperkalemia is needed. These results suggest that compound 1 can be developed as a promising oral CYP11B2 inhibitor for pharmaceutical applications. Compound 1 could also be a useful compound for clarifying the role of aldosterone in cardiac hypertrophy.

Aldosterone and cardiovascular remodelling: focus on myocardial failure

Heart failure is a clinical syndrome that may result from different disease states or conditions that injure the myocardium. The activation of circulating neurohormones, particularly aldosterone, may play a pivotal role in left ventricular (LV) remodelling. The Randomized Aldactone Evaluation Study and Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival trial have emphasised the clinical importance of aldosterone. This review addresses some of the proposed mechanisms of LV remodelling in heart failure.

CS-3150, a novel non-steroidal mineralocorticoid receptor antagonist, prevents hypertension and cardiorenal injury in Dahl salt-sensitive hypertensive rats

The present study was designed to evaluate the antihypertensive and cardiorenal protective effects of CS-3150, a novel non-steroidal mineralocorticoid receptor antagonist, in Dahl salt-sensitive hypertensive rats (DS rats), and to compare the effects with spironolactone and eplerenone. DS rats were fed a control diet (0.3% NaCl) or high salt diet (8% NaCl) from 7 weeks of age. CS-3150 (0.25-2mg/kg), spironolactone (10-100mg/kg) or eplerenone (10-100mg/kg) were orally administered once a day to DS rats fed a high salt diet for 7 weeks. The high salt diet significantly increased systolic blood pressure, which was prevented by treatment with CS-3150 in a dose-dependent manner with no hyperkalemia (>5.5mEq/L). The antihypertensive effect of CS-3150 (0.5mg/kg) was equivalent to that of spironolactone (100mg/kg) and eplerenone (100mg/kg). CS-3150 also suppressed proteinuria and renal hypertrophy induced by the high salt diet. Histopathological examination of kidneys showed that CS-3150 markedly ameliorated glomerulosclerosis, tubular injury and tubulointerstitial fibrosis. In addition, CS-3150 inhibited left ventricular hypertrophy and elevation of plasma brain natriuretic peptide level. In contrast, the cardiorenal protective effects of spironolactone or eplerenone were partial, and the dose-dependency was not clear, especially in eplerenone-treated rats. These results indicate that chronic treatment with CS-3150 exerts antihypertensive and cardiorenal protective effects in a DS hypertensive rat model, and its potency is much superior to that of spironolactone or eplerenone. Thus, CS-3150 could be a promising agent for the treatment of hypertension and cardiorenal disorders.

Role of biomarkers in cardiac structure phenotyping in heart failure with preserved ejection fraction: critical appraisal and practical use

Heart failure (HF) with preserved ejection fraction (HFpEF) is a heterogeneous clinical syndrome characterized by cardiovascular, metabolic, and pro-inflammatory diseases associated with advanced age and extracardiac comorbidities. All of these conditions finally lead to impairment of myocardial structure and function. The large phenotypic heterogeneity of HFpEF from pathophysiological underpinnings presents a major hurdle to HFpEF therapy. The new therapeutic approach in HFpEF should be targeted to each HF phenotype, instead of the 'one-size-fits-all' approach, which has not been successful in clinical trials. Unless the structural and biological determinants of the failing heart are deeply understood, it will be impossible to appropriately differentiate HFpEF patients, identify subtle myocardial abnormalities, and finally reverse abnormal cardiac function. Based on evidence from endomyocardial biopsies, some of the specific cardiac structural phenotypes to be targeted in HFpEF may be represented by myocyte hypertrophy, interstitial fibrosis, myocardial inflammation associated with oxidative stress, and coronary disease. Once the diagnosis of HFpEF has been established, a potential approach could be to use a panel of biomarkers to identify the main cardiac structural HFpEF phenotypes, guiding towards more appropriate therapeutic strategies. Accordingly, the purpose of this review is to investigate the potential role of biomarkers in identifying different cardiac structural HFpEF phenotypes and to discuss the merits of a biomarker-guided strategy in HFpEF.

Challenging aspects of treatment strategies in heart failure with preserved ejection fraction: "Why did recent clinical trials fail?"

Heart failure (HF) is the leading cause of hospitalization among older adults and the prevalence is growing with the aging populations in the Western countries. Epidemiologic reports suggest that approximately 50% of patients who have signs or symptoms of HF have preserved left ventricular ejection fraction. This HF type predominantly affects women and the elderly with other co-morbidities, such as diabetes, hypertension, and overt volume status. Most of the current treatment strategies are based on morbidity benefits such as quality of life and reduction of clinical HF symptoms. Treatment of patients with HF with preserved ejection fraction displayed disappointing results from several large randomized controlled trials. The heterogeneity of HF with preserved ejection fraction, understood as complex syndrome, seems to be one of the primary reasons. Here, we present an overview of the current management strategies with available evidence and new therapeutic approach from drugs currently in clinical trials, which target diastolic dysfunction, chronotropic incompetence, and risk factor management. We provide an outline and interpretation of recent clinical trials that failed to improve outcome and survival in patients with HF with preserved ejection fraction.

CB1 cannabinoid receptor antagonist attenuates left ventricular hypertrophy and Akt-mediated cardiac fibrosis in experimental uremia

Cannabinoid receptor type 1 (CB1R) plays an important role in the development of myocardial hypertrophy and fibrosis-2 pathological features of uremic cardiomyopathy. However, it remains unknown whether CB1R is involved in the pathogenesis of uremic cardiomyopathy. Here, we aimed to elucidate the role of CB1R in the development of uremic cardiomyopathy via modulation of Akt signalling. The heart size and myocardial fibrosis were evaluated by echocardiography and immunohistochemical staining, respectively, in 5/6 nephrectomy chronic kidney disease (CKD) mice treated with a CB1R antagonist. CB1R and fibrosis marker expression levels were determined by immunoblotting in H9c2 cells exposed to the uremic toxin indoxyl sulfate (IS), with an organic anion transporter 1 inhibitor or a CB1R antagonist or agonist. Akt phosphorylation was also assessed to examine the signaling pathways downstream of CB1R activation induced by IS in H9c2 cells. CKD mice exhibited marked left ventricular hypertrophy and myocardial fibrosis, which were reversed by treatment with the CB1R antagonist. CB1R, collagen I, transforming growth factor (TGF)-β, and α-smooth muscle actin (SMA) expression showed time- and dose-dependent upregulation in H9c2 cells treated with IS. The inhibition of CB1R by either CB1R antagonist or small interfering RNA-mediated knockdown attenuated the expression of collagen I, TGF-β, and α-SMA in IS-treated H9c2 cells, while Akt phosphorylation was enhanced by CB1R agonist and abrogated by CB1R antagonist in these cells. In summary, we conclude that CB1R blockade attenuates LVH and Akt-mediated cardiac fibrosis in a CKD mouse model. Uremic toxin IS stimulates the expression of CB1R and fibrotic markers and CB1R inhibition exerts anti-fibrotic effects via modulation of Akt signaling in H9c2 myofibroblasts. Therefore, the development of drugs targeting CB1R may have therapeutic potential in the treatment of uremic cardiomyopathy.

Hydrogen Sulfide: A Therapeutic Candidate for Fibrotic Disease?

Fibrotic diseases including chronic kidney disease, liver cirrhosis, idiopathic pulmonary fibrosis, and chronic disease account for 45% mortality in the developed countries and pose a great threat to the global health. Many great targets and molecules have been reported to be involved in the initiation and/or progression of fibrosis, among which inflammation and oxidative stress are well-recognized modulation targets. Hydrogen sulfide (H₂S) is the third gasotransmitter with potent properties in inhibiting inflammation and oxidative stress in various organs. Recent evidence suggests that plasma H₂S level is decreased in various animal models of fibrotic diseases and supplement of exogenous H₂S is able to ameliorate fibrosis in the kidney, lung, liver, and heart. This leads us to propose that modulation of H₂S production may represent a promising therapeutic venue for the treatment of a variety of fibrotic diseases. Here, we summarize and discuss the current data on the role and underlying mechanisms of H₂S in fibrosis diseases related to heart, liver, kidney, and other organs.

[New therapy concepts for heart failure with preserved ejection fraction]

The management of patients with heart failure and preserved ejection fraction (HFpEF) remains challenging and requires an accurate diagnosis. Although currently no convincing therapy that can prolong survival in patients with HFpEF has been established, treatment of fluid retention, heart rate and control of comorbidities are important cornerstones to improve the quality of life and symptoms. In recent years many new therapy targets have been tested for development of successful interventional strategies for HFpEF. Insights into new mechanisms of HFpEF have shown that heart failure is associated with dysregulation of the nitric oxide-cyclic guanosine monophosphate-protein kinase (NO-cGMP-PK) pathway. Two new drugs are currently under investigation to test whether this pathway can be significantly improved by either the neprilysin inhibitor LCZ 696 due to an increase in natriuretic peptides or by the soluble guanylate cyclase stimulator vericiguat, which is also able to increase cGMP. In addition, several preclinical or early phase studies which are currently investigating new mechanisms for matrix, intracellular calcium and energy regulation including the role of microRNAs and new devices are presented and discussed.

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.

The influence of enalapril and spironolactone on electrolyte concentrations in Doberman pinschers with dilated cardiomyopathy

The combination of an angiotensin-converting enzyme inhibitor (ACEI) with an aldosterone receptor antagonist can increase serum potassium and magnesium and lower serum sodium concentrations. The objective of this study was to retrospectively determine whether an ACEI and spironolactone can be co-administered to Doberman pinschers with occult dilated cardiomyopathy without serious adverse influences on serum electrolyte concentrations. Between 2001 and 2007, 26 client-owned Doberman pinschers were given enalapril, spironolactone, and carvedilol and followed for at least 6 months. Most dogs had been prescribed mexiletine for ventricular tachyarrhythmia suppression. Dogs were treated with pimobendan when congestive heart failure was imminent. Baseline and follow-up (3-10 visits) color-flow Doppler echocardiograms, serum urea nitrogen (SUN), creatinine, sodium, potassium, and magnesium concentration data were tabulated. Compared to baseline data, there were no significant changes in serum sodium or serum creatinine concentrations. Serum magnesium (P = 0.003), serum potassium (P = 0.0001), and SUN (P = 0.0001) concentrations increased significantly with time. Although the combination of ACEI and spironolactone was associated with significant increases in magnesium, potassium, and SUN concentrations, these changes were of no apparent clinical relevance. At the dosages used in this study, this combination of drugs appears safe.

Management strategies for heart failure with preserved ejection fraction

The management of heart failure with preserved ejection fraction (HFpEF) is challenging and requires an accurate diagnosis. Although currently there is no convincing therapy that prolongs survival in patients with HFpEF, treatment of fluid retention and of comorbidities, such as hypertension, myocardial ischemia, and atrial fibrillation, may improve symptoms and quality of life. Future outcome trials testing the efficacy of promising new agents will have better characterization of patient phenotype to maximize the potential response to therapies. This article provides current management strategies available for HFpEF, gives an overview of previous trials that have failed to prove the benefit of therapies to improve outcomes, and highlights promising novel therapies.

The effect of vitamin d on aldosterone and health status in patients with heart failure

BACKGROUND

Vitamin D deficiency is associated with heart failure (HF) events, and in animal models vitamin D down-regulates renin-angiotensin-aldosterone system hormones.

METHODS

Patients with New York Heart Association (NYHA) functional class II-IV HF and a 25OH-D level ≤37.5 ng/mL received 50,000 IU vitamin D3 weekly (n = 31) or placebo (n = 33) for 6 months. Serum aldosterone, renin, echocardiography, and health status were determined at baseline and 6 months.

RESULTS

Mean age of participants was 65.9 ± 10.4 years, 48% were women, 64% were African American, mean ejection fraction was 37.6 ± 13.9%, 36% were in NYHA functional class III, and 64% were in class II. The vitamin D group increased serum 25OH-D (19.1 ± 9.3 to 61.7 ± 20.3 ng/mL) and the placebo group did not (17.8 ± 9.0 to 17.4 ± 9.8 ng/mL). Aldosterone decreased in the vitamin D group (10.0 ± 11.9 to 6.2 ± 11.6 ng/dL) and not in the placebo group (8.9 ± 8.6 to 9.0 ± 12.4 ng/dL; P = .02). There was no difference between groups in renin, echocardiographic measures, or health status from baseline to 6 months. Modeling indicated that variables which predicted change in aldosterone included receiving vitamin D, increasing age, African American race, and lower glomerular filtration rate.

CONCLUSIONS

Vitamin D3 repletion decreases aldosterone in patients with HF and low serum vitamin D. Vitamin D may be an important adjunct to standard HF therapy. Further study will assess if vitamin D provides long-term benefit for patients with HF.

Heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction accounts for up to 50% of hospitalized heart failure patients and is associated with significant mortality and morbidity. The pathophysiology is heterogeneous and not very well defined, which explains the lack of disease-specific therapies. The principles of treating heart failure with preserved ejection fraction are controlling volume with diuretics and diet, and controlling the comorbidities, mainly the hypertension. Further research is encouraged to ascertain the key components of the disease that will serve as targets for therapy.

Mineralocorticoid receptor antagonist in heart failure: Past, present and future perspectives

Aldosterone is involved in various deleterious effects on the cardiovascular system, including sodium and fluid retention, myocardial fibrosis, vascular stiffening, endothelial dysfunction, catecholamine release and stimulation of cardiac arrhythmias. Therefore, aldosterone receptor blockade may have several potential benefits in patients with cardiovascular disease. Mineralocorticoid receptor antagonists (MRAs) have been shown to prevent many of the maladaptive effects of aldosterone, in particular among patients with heart failure (HF). Randomized controlled trials have demonstrated efficacy of MRA in heart failure with reduced ejection fraction, both in patients with NYHA functional classes III and IV and in asymptomatic and mildly symptomatic patients (NYHA classes I and II). Recent data in patients with heart failure with preserved ejection fraction are encouraging. MRA could also have anti-arrhythmic effects on atrial and ventricular arrhythmias and may be helpful in patient ischemic heart disease through prevention of myocardial fibrosis and vascular damage. This article aims to discuss the pathophysiological effects of aldosterone in patients with cardiovascular disease and to review the current data that support the use of MRA in heart failure.

The pathogenesis of cardiac fibrosis

Cardiac fibrosis is characterized by net accumulation of extracellular matrix proteins in the cardiac interstitium, and contributes to both systolic and diastolic dysfunction in many cardiac pathophysiologic conditions. This review discusses the cellular effectors and molecular pathways implicated in the pathogenesis of cardiac fibrosis. Although activated myofibroblasts are the main effector cells in the fibrotic heart, monocytes/macrophages, lymphocytes, mast cells, vascular cells and cardiomyocytes may also contribute to the fibrotic response by secreting key fibrogenic mediators. Inflammatory cytokines and chemokines, reactive oxygen species, mast cell-derived proteases, endothelin-1, the renin/angiotensin/aldosterone system, matricellular proteins, and growth factors (such as TGF-β and PDGF) are some of the best-studied mediators implicated in cardiac fibrosis. Both experimental and clinical evidence suggests that cardiac fibrotic alterations may be reversible. Understanding the mechanisms responsible for initiation, progression, and resolution of cardiac fibrosis is crucial to design anti-fibrotic treatment strategies for patients with heart disease.

Twenty-four-hour urinary aldosterone predicts inappropriate left ventricular mass index in patients with primary aldosteronism

Objective. Primary aldosteronism (PA) is associated with inappropriate left ventricular hypertrophy (LVH) in relation to a given gender and body size. There is no ideal parameter to predict the presence of LVH or inappropriate LVH in patients with PA. We investigate the performance of 24-hour urinary aldosterone level, plasma renin activity and aldosterone-to-renin ratio on this task. Methods. We performed echocardiography in 106 patients with PA and 31 subjects with essential hypertension (EH) in a tertiary teaching hospital. Plasma renin activity, aldosterone concentration, and 24-hour urinary aldosterone level were measured. Results. Only 24-hour urinary aldosterone was correlated with left ventricular mass index (LVMI) and excess LVMI among these parameters. The multivariate analysis revealed the urinary aldosterone level as an independent predictor for LVMI and excess LVMI. Analyzing the ability of urinary aldosterone, plasma aldosterone concentration, and plasma aldosterone-to-renin ratio to identify the presence of LVH (ROC AUC = 0.701, 0.568, 0.656, resp.) and the presence of inappropriate LV mass index (defined as measured LVMI in predicting LVMI ratio >135%) (ROC area under curve = 0.61, 0.43, 0.493, resp.) revealed the better performance of 24-hour urinary aldosterone. Conclusions. In conclusion, 24-hour urinary aldosterone level performed better to predict the presence of LVH and inappropriate LVMI in patients with PA.

Mineralocorticoid receptors and the heart, multiple cell types and multiple mechanisms: a focus on the cardiomyocyte

MR (mineralocorticoid receptor) activation in the heart plays a central role in the development of cardiovascular disease, including heart failure. The MR is present in many cell types within the myocardium, including cardiomyocytes, macrophages and the coronary vasculature. The specific role of the MR in each of these cell types in the initiation and progression of cardiac pathophysiology is not fully understood. Cardiomyocyte MRs are increasingly recognized to play a role in regulating cardiac function, electrical conduction and fibrosis, through direct signal mediation and through paracrine MR-dependent activity. Although MR blockade in the heart is an attractive therapeutic option for the treatment of heart failure and other forms of heart disease, current antagonists are limited by side effects owing to MR inactivation in other tissues (including renal targets). This has led to increased efforts to develop therapeutics that are more selective for cardiac MRs and which may have reduced the occurrence of side effects in non-cardiac tissues. A major clinical consideration in the treatment of cardiovascular disease is of the differences between males and females in the incidence and outcomes of cardiac events. There is clinical evidence that female sensitivity to endogenous MRs is more pronounced, and experimentally that MR-targeted interventions may be more efficacious in females. Given that sex differences have been described in MR signalling in a range of experimental settings and that the MR and oestrogen receptor pathways share some common signalling intermediates, it is becoming increasingly apparent that the mechanisms of MRs need to be evaluated in a sex-selective manner. Further research targeted to identify sex differences in cardiomyocyte MR activation and signalling processes has the potential to provide the basis for the development of cardiac-specific MR therapies that may also be sex-specific.

Is there benefit in dual renin-angiotensin-aldosterone system blockade? No, yes and maybe: a guide for the perplexed

Since the initial discovery of Angiotensin converting enzyme inhibitors (ACEI) in the 1960s and the launch of Captopril as the first available for clinical use in the 1970s, there now exist three other classes of drugs that block the renin angiotensin aldosterone system (RAAS): the angiotensin II receptor blockers (ARB), aldosterone antagonists (AA) and direct renin inhibitors (DRI). With the proven efficacy of RAAS blockers as monotherapy in many arenas there has been considerable interest in the use of dual therapy combinations of these medications that target different points in the pathway. By potentially offering a more complete RAAS blockade with a commensurate enhanced clinical effect, the strong biological rationale for dual therapy has led to it being embraced by clinicians as a treatment option, for hypertension and nephroprotection in particular. However, the initial enthusiasm for this treatment has been tempered by the recent results from several large trials such as ONTARGET and ALTITUDE, which do not support a specific dual therapy approach. In contrast, there is supportive evidence for dual blockade of specific combinations in selected patient groups and data are lacking for others. In the wake of this complex contemporary evidence, the conundrum now faced by clinicians committed to individualised care is, for which patients dual therapy could still be of benefit. This review examines for the practising clinician the current 'state of play' for dual blockade of various combinations and a perspective on its use in cardio-renal disease and diabetic complications.

Vascular-targeted therapies for Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is the most common muscular dystrophy and an X-linked recessive, progressive muscle wasting disease caused by the absence of a functional dystrophin protein. Dystrophin has a structural role as a cytoskeletal stabilization protein and protects cells against contraction-induced damage. Dystrophin also serves a signaling role through mechanotransduction of forces and localization of neuronal nitric oxide synthase (nNOS), which produces nitric oxide (NO) to facilitate vasorelaxation. In DMD, the signaling defects produce inadequate tissue perfusion caused by functional ischemia due to a diminished ability to respond to shear stress induced endothelium-dependent dilation. Additionally, the structural defects seen in DMD render myocytes with an increased susceptibility to mechanical stress. The combination of both defects is necessary to generate myocyte damage, which induces successive rounds of myofiber degeneration and regeneration, loss of calcium homeostasis, chronic inflammatory response, fibrosis, and myonecrosis. In individuals with DMD, these processes inevitably cause loss of ambulation shortly after the first decade and an abbreviated life with death in the third or fourth decade due to cardio-respiratory anomalies. There is no known cure for DMD, and although the culpable gene has been identified for more than twenty years, research on treatments has produced few clinically relevant results. Several recent studies on novel DMD therapeutics are vascular targeted and focused on attenuating the inherent functional ischemia. One approach improves vasorelaxation capacity through pharmaceutical inhibition of either phosphodiesterase 5 (PDE5) or angiotensin-converting enzyme (ACE). Another approach increases the density of the underlying vascular network by inducing angiogenesis, and this has been accomplished through either direct delivery of vascular endothelial growth factor (VEGF) or by downregulating the VEGF decoy-receptor type 1 (VEGFR-1 or Flt-1). The pro-angiogenic approaches also seem to be pro-myogenic and could resolve the age-related decline in satellite cell (SC) quantity seen in mdx models through expansion of the SC juxtavascular niche. Here we review these four vascular targeted treatment strategies for DMD and discuss mechanisms, proof of concept, and the potential for clinical relevance associated with each therapy.

Primary aldosteronism with concurrent primary hyperparathyroidism in a patient with arrhythmic disorders

A 25-year-old Caucasian woman was admitted to our department with severe hypokalemia that was associated with hypercalcemia. An endocrinological investigation showed the coexistence of primary hyperparathyroidism (PHPT) and primary aldosteronism (PA), arising from an adenoma of the left cortical adrenal gland. The patient underwent left laparoscopic adrenalectomy, but refused the surgical neck exploration that would be required for parathyroidectomy. The post-operative course was uneventful, and the patient realized a normalization of her potassium serum level and a reduction of her blood pressure values. We herein report the important issues regarding the management of a severe electrolyte imbalance, in view of the reciprocal interaction between aldosterone and parathyroid hormone, and their combined potential for causing cardiovascular damage.

3-Pyridyl substituted aliphatic cycles as CYP11B2 inhibitors: aromaticity abolishment of the core significantly increased selectivity over CYP1A2

Aldosterone synthase (CYP11B2) is a promising therapeutic target for the treatment of cardiovascular diseases related to abnormally high aldosterone levels. On the basis of our previously identified lead compounds I–III, a series of 3-pyridinyl substituted aliphatic cycles were designed, synthesized and tested as CYP11B2 inhibitors. Aromaticity abolishment of the core was successfully applied to overcome the undesired CYP1A2 inhibition. This study resulted in a series of potent and selective CYP11B2 inhibitors, with compound 12 (IC₅₀ = 21 nM, SF = 50) as the most promising one, which shows no inhibition toward CYP1A2 at 2 µM. The design conception demonstrated in this study can be helpful in the optimization of CYP inhibitor drugs regarding CYP1A2 selectivity.

Auto-amplification of cortisol actions in human carotid atheroma is linked to arterial remodeling and stroke

High cortisol and aldosterone levels increase cardiovascular risk, but the respective roles of each hormone within the arterial wall remain controversial. We tested the hypothesis that cortisol production within the arterial wall may contribute to atherosclerotic remodeling and act through illicit activation of the mineralocorticoid receptor (MR). Gene expression studies of the corticoid system components and marker genes of the atherosclerotic process in human carotid atheroma plaque and nearby macroscopically intact tissue (MIT) were considered together with clinical data and compared with pharmacological stimulations of human vascular smooth muscle cells (VSMCs) in contractile or lipid-storing phenotypes. The components of corticoid production and action were present and active within the human carotid wall and VSMCs. Atheroma plaque and lipid-storing VSMCs expressed 11β-hydroxysteroid deshydrogenase-1 (11β-HSD1) at two- to tenfold higher levels than MIT or contractile VSMCs. The 11β-HSD1 expression was stimulated by cortisol and cortisone, especially in lipid-storing VSMCs. MR mRNA level was lower in atheroma and lipid-storing VSMCs and downregulated via MR by fludrocortisone and cortisol. Cortisol upregulated collagen1 and MCP-1 mRNAs via the glucocorticoid receptor (GRα), in both VSMC phenotypes, whereas fludrocortisone stimulated the collagen1 expression only in lipid-storing VSMCs. The GRα mRNA level in MIT was higher in patients with previous stroke and correlated positively with the collagen1 mRNA but negatively with diastolic blood pressure. Local cortisol production by 11β-HSD1, and its action via high parietal GRα could be relevant from the first step of atherosclerotic remodeling and auto-amplify with transdifferentiation of VSMCs during atheroma progression.

Renal dysfunction in heart failure

Renal dysfunction is a common, important comorbidity in patients with both chronic and acute heart failure (HF). Chronic kidney disease and worsening renal function (WRF) are associated with worse outcomes, but our understanding of the complex bidirectional interactions between the heart and kidney remains poor. When addressing these interactions, one must consider the impact of intrinsic renal disease resulting from medical comorbidities on HF outcomes. WRF may result from any number of important processes. Understanding the role of each of these factors and their interplay are essential in understanding how to improve outcomes in patients with renal dysfunction and HF.

PAI-1 in tissue fibrosis

Fibrosis is defined as a fibroproliferative or abnormal fibroblast activation-related disease. Deregulation of wound healing leads to hyperactivation of fibroblasts and excessive accumulation of extracellular matrix (ECM) proteins in the wound area, the pathological manifestation of fibrosis. The accumulation of excessive levels of collagen in the ECM depends on two factors: an increased rate of collagen synthesis and or decreased rate of collagen degradation by cellular proteolytic activities. The urokinase/tissue type plasminogen activator (uPA/tPA) and plasmin play significant roles in the cellular proteolytic degradation of ECM proteins and the maintenance of tissue homeostasis. The activities of uPA/tPA/plasmin and plasmin-dependent MMPs rely mostly on the activity of a potent inhibitor of uPA/tPA, plasminogen activator inhibitor-1 (PAI-1). Under normal physiologic conditions, PAI-1 controls the activities of uPA/tPA/plasmin/MMP proteolytic activities and thus maintains the tissue homeostasis. During wound healing, elevated levels of PAI-1 inhibit uPA/tPA/plasmin and plasmin-dependent MMP activities, and, thus, help expedite wound healing. In contrast to this scenario, under pathologic conditions, excessive PAI-1 contributes to excessive accumulation of collagen and other ECM protein in the wound area, and thus preserves scarring. While the level of PAI-1 is significantly elevated in fibrotic tissues, lack of PAI-1 protects different organs from fibrosis in response to injury-related profibrotic signals. Thus, PAI-1 is implicated in the pathology of fibrosis in different organs including the heart, lung, kidney, liver, and skin. Paradoxically, PAI-1 deficiency promotes spontaneous cardiac-selective fibrosis. In this review, we discuss the significance of PAI-1 in the pathogenesis of fibrosis in multiple organs.

Contemporary medical management of systolic heart failure

Pharmacological therapy of systolic left ventricular dysfunction has evolved over the past 3 decades. Current therapy is focused primarily on the regulation of the renin-angiotensin-aldosterone axis and sympathetic nervous system. Additional targets of pharmacotherapy include vasoconstriction, impaired nitric oxide metabolism, inflammation and improving myocardial function. As therapies in chronic systolic heart failure have evolved beyond diuretics and digoxin, so too has mortality improved. Future directions in the management of heart failure include cell-based and genetic therapy, and further refinement of current therapy through genetics.

Aliskiren reduced renal fibrosis in mice with chronic ischemic kidney injury--beyond the direct renin inhibition

Chronic renal ischemia leads to renal fibrosis and atrophy. Activation of the renin-angiotensin-aldosterone system is one of the main mechanisms driving chronic renal ischemic injury. The aim of the present study was to define the effect of aliskiren in chronic ischemia of the kidney. Two-kidney, one-clip mice were used to study chronic renal ischemia. Aliskiren significantly lowered the blood pressure in mice with renal artery constriction (92.1±1.1 vs. 81.0±1.8 mm Hg, P<0.05). Renin expression was significantly increased in ischemic kidneys when treated with aliskiren. In addition, (Pro)renin receptor expression was decreased by aliskiren in ischemic kidneys. Aliskiren treatment significantly increased klotho expression and reduced the expression of fibrogenic cystokines, caspase-3 and Bax in ischemic kidneys. Histological examination revealed that aliskiren significantly reduced the nephrosclerosis score (4.5±1.9 vs. 7.3±0.4, P<0.05). Immunofluorescence staining also showed that aliskiren decreased the deposition of interstitial collagen I in ischemic kidneys. In conclusion, direct renin inhibition significantly reduced renal fibrosis and apoptosis following chronic renal ischemia.

Pharmacodynamics of ellagic acid on cardiac troponin-T, lyosomal enzymes and membrane bound ATPases: mechanistic clues from biochemical, cytokine and in vitro studies

The anti lipid peroxidative and antioxidant effects of ellagic acid against isoproterenol-induced myocardial infarcted rats were reported previously. This study was designed to evaluate the protective effects of ellagic acid on the levels of cardiac troponin-T, lysosomal enzymes, and membrane bound ATPases along with the role of pro inflammatory cytokine. Male albino Wistar rats were pretreated with ellagic acid (7.5 and 15 mg/kg body weight) daily for a period of 10 days. After the pretreatment period isoproterenol (100mg/kg) was subcutaneously injected to rats twice at an interval of 24h. The protective effects of pretreatment with ellagic acid were measured by biochemical analysis and reverse transcriptase polymerase chain reaction. Evidence of myocardial infarction in isoproterenol induced rats included significant increase in the serum level of cardiac troponin-T and decreased levels of creatine kinase and lactate dehydrogenase in heart tissue homogenate .The pretreatment with ellagic acid restored the levels of cardiac markers in the serum and heart tissue homogenates. The activities of lysosomal enzymes (β-d-glucuronidase, β-N-acetyl glucosaminidase, β-galactosidase, cathepsin-d and acid phosphatase) were increased significantly in the serum and heart tissue of isoproterenol-induced rats. The activity of Na(+)/K(+)ATPase declined while the activities of Ca(2+)ATPase and Mg(2+)ATPase were increased significantly in the heart of isoproterenol-induced rats. Pretreatment with ellagic acid restored the activities of lysosomal enzymes and membrane bound ATPases. The higher expressions of pro-inflammatory cytokines such as interleukin-1β, interleukin-6 and tumour necrosis factor-α in the isoproterenol-induced rats were controlled by the pretreatment with ellagic acid. Our results imply that oral pretreatment with ellagic acid protects the heart lysosomal membrane against isoproterenol-induced cardiac damage. The observed effects might be due to the free radical scavenging, membrane stabilizing and anti-inflammatory properties of ellagic acid.

Structural, functional, and molecular alterations produced by aldosterone plus salt in rat heart: association with enhanced serum and glucocorticoid-regulated kinase-1 expression

We aimed to evaluate the structural, functional, inflammatory, and oxidative alterations, as well as serum and glucocorticoid-regulated kinase-1 (SGK-1) expression, produced in rat heart by aldosterone + salt administration. Fibrosis mediators such as connective tissue growth factor, matrix metalloproteinase 2, and tissue inhibitor of metalloproteinases 2 were also evaluated. Treatment with spironolactone was evaluated to prove mineralocorticoid mediation. Male Wistar rats received aldosterone (1 mg[middle dot]kg-1[middle dot]d-1) + 1% NaCl for 3 weeks. Half of the animals were treated with spironolactone (200 mg[middle dot]kg-1[middle dot]d-1). Systolic and diastolic blood pressures, left ventricle (LV) systolic pressure, and LV end-diastolic pressure were elevated (P < 0.05) in aldosterone + salt-treated rats. In aldosterone + salt-treated rats, -dP/dt decreased (P < 0.05), but +dP/dt was similar in all groups. Spironolactone normalized (P < 0.05) systolic blood pressure, diastolic blood pressure, LV systolic pressure, LV end-diastolic pressure, and -dP/dt. Relative heart weight, collagen content, messenger RNA expression of transforming growth factor beta, connective tissue growth factor, matrix metalloproteinase 2, tissue inhibitor of metalloproteinases 2, tumor necrosis factor alpha, interleukin-1[beta], p22phox, endothelial nitric oxide synhtase, and SGK-1 were increased (P < 0.05) in aldosterone + salt-treated rats, being reduced by spironolactone (P < 0.05). SGK-1 might be a key mediator in the structural, functional, and molecular cardiac alterations induced by aldosterone + salt in rats. All the observed changes and mediators are related with the activation of mineralocorticoid receptors.

Renin-angiotensin-aldosterone blockade for cardiovascular disease prevention

The renin-angiotensin-aldosterone system (RAAS) plays a significant role in pathophysiology of multiple disease states. RAAS blockade is beneficial in patients with hypertension, acute myocardial infarction, chronic heart failure, stroke, and diabetic renal disease. RAAS blockade with the combination angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) has demonstrated conflicting results in recent clinical trials. This article reviews the latest evidence of isolated ACEI or ARB use, their combination, and the role of aldosterone blockers and direct renin inhibitors in patients at risk, and makes recommendations for their use in the prevention of morbidity and mortality in cardiovascular disease.

Update: Systemic Diseases and the Cardiovascular System (II). The endocrine system and the heart: a review

Normal endocrine function is essential for cardiovascular health. Disorders of the endocrine system, consisting of hormone hyperfunction and hypofunction, have multiple effects on the cardiovascular system. In this review, we discuss the epidemiology, diagnosis, and management of disorders of the pituitary, thyroid, parathyroid, and adrenal glands, with respect to the impact of endocrine dysfunction on the cardiovascular system. We also review the cardiovascular benefits of restoring normal endocrine function.

Prognostic Implications of Diuretic Dose in Chronic Heart Failure

Background: Prognostic implications of diuretics dose are not completely understood. We aim to study the association between diuretic doses and long-term prognosis in patients with chronic stable heart failure (HF). Methods and Results: We conducted a retrospective cohort study of 244 patients followed at an outpatient HF clinic. Admission criteria were clinical stability in the previous 3 months and optimized medical therapy. Demographic characteristics, clinical, and laboratory parameters were recorded. Patients were followed for 2 years and the outcome was defined as all-cause death or hospital admission due to HF worsening. Patients on ≤80 mg furosemide were compared with those on higher doses. Patients were grouped according to furosemide dose (≤80 mg and >80 mg/d) and according to volemia as assessed by the sodium retention score: <3 (euvolemia) versus ≥3 (hypervolemia). Patients on higher diuretic doses (n = 79) were older, more hypervolemic, and more symptomatic. Patients on >80 mg furosemide had a higher risk of death or hospital admission (hazard ratio [HR]: 2.07, 95% confidence interval [CI]: 1.37-3.1). For each 40-mg furosemide tablet, there was a 67% increase in risk of an adverse outcome within 2 years. The increase in risk was independent of other variables crudely associated with prognosis. Among euvolemic patients, those on ≤80 mg/d furosemide performed better than those on higher doses. Among hypervolemic patients, the diuretic dose had no prognostic implications. Conclusions: Higher diuretic doses associated strongly and independently with adverse long-term outcome in chronic HF. Possibly, in euvolemic patients, efforts should be made to reduce diuretic dose.