Addition of spironolactone to angiotensin-converting enzyme inhibition in heart failure improves endothelial vasomotor dysfunction: role of vascular superoxide anion formation and endothelial nitric oxide synthase expression

Anti-Arrhythmic Effects of Heart Failure Guideline-Directed Medical Therapy and Their Role in the Prevention of Sudden Cardiac Death: From Beta-Blockers to Sodium-Glucose Cotransporter 2 Inhibitors and Beyond

Sudden cardiac death (SCD) accounts for a substantial proportion of mortality in heart failure with reduced ejection fraction (HFrEF), frequently triggered by ventricular arrhythmias (VA). This review aims to analyze the pathophysiological mechanisms underlying VA and SCD in HFrEF and evaluate the effectiveness of guideline-directed medical therapy (GDMT) in reducing SCD. Beta-blockers, angiotensin receptor-neprilysin inhibitors, and mineralocorticoid receptor antagonists have shown significant efficacy in reducing SCD risk. While angiotensin-converting enzyme inhibitors and angiotensin receptor blockers exert beneficial impacts on the renin-angiotensin-aldosterone system, their direct role in SCD prevention remains less clear. Emerging treatments like sodium-glucose cotransporter 2 inhibitors show promise but necessitate further research for conclusive evidence. The favorable outcomes of those molecules on VA are notably attributable to sympathetic nervous system modulation, structural remodeling attenuation, and ion channel stabilization. A multidimensional pharmacological approach targeting those pathophysiological mechanisms offers a complete and synergy approach to reducing SCD risk, thereby highlighting the importance of optimizing GDMT for HFrEF. The current landscape of HFrEF pharmacotherapy is evolving, with ongoing research needed to clarify the full extent of the anti-arrhythmic benefits offered by both existing and new treatments.

Serum aldosterone in right ventricular failure versus left ventricular failure before and after mineralocorticoid receptor antagonists: case-control clinical trial

BACKGROUND

Heart failure (HF) is a global growing health threat. This case-control clinical trial aimed to detect the predictive value and difference in aldosterone level between right side heart failure, heart failure with decreased ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF) and compare the efficacy and safety of adding mineralocorticoid receptor antagonist (MRA) for treatment.

PATIENTS AND METHODS

We recruited 151 participants, 135 HF patients divided equally into 45 patients in each group:(1) right side HF (2) HFrEF and (3) HFpEF and 16 healthy controls. Serum aldosterone, troponin and echocardiography were evaluated at the beginning of the study, three and six months after administration of MRA.

RESULTS

Aldosterone level was significantly greater in HF patients relative to controls. Aldosterone level can detect HF with excellent accuracy. There were significantly lower levels of aldosterone in right side HF compared to left side HF. There was a significant decrease in right ventricle dimensions, pulmonary artery systolic pressure and pulmonary artery size and significant increase in tricuspid annular plane systolic excursion after treatment in patients with right side HF. In the HFrEF group, there was a significant decrease in left ventricular end diastolic dimension and a significant increase in left ventricular EF after treatment. In the HFpEF group, there was a significant decrease in E/A and E/e' after treatment.

CONCLUSIONS

Aldosterone may have pathogenic role in HF. Measuring and follow-up of aldosterone levels should be considered in HF patients. MRA treatment gives a significant improvement in right side HF group.

Cardiovascular and Renal Outcomes with Finerenone, a Selective Mineralocorticoid Receptor Antagonist

Overactivation of the renin-angiotensin-aldosterone system (RAAS) has been shown to be pathologic in heart failure and albuminuric chronic kidney disease (CKD), triggering pro-inflammatory and pro-fibrotic cellular pathways. The standard of care in these disease states includes treatment with angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers. Mineralocorticoid receptor antagonists (MRAs) are also a mainstay in the treatment of heart failure with reduced ejection fraction; however, therapy is often limited by treatment-related hyperkalemia. In albuminuric CKD, the risk of hyperkalemia, acute kidney injury (AKI), and hypotension also remains significant. Finerenone is a novel non-steroidal MRA that may obviate some of these concerns and have therapeutic potential in additional patient populations. Finerenone was developed using the chemical structure of a dihydropyridine channel blocker but optimized to create a bulky MRA without any activity at the L-type calcium channel. It has several novel cellular mechanisms that may account for its ability to reduce cardiac hypertrophy and proteinuria more efficiently than an equinatriuretic dose of a steroidal MRA, while retaining anti-inflammatory and anti-fibrotic properties. Finerenone also has a lower rate of treatment-related hyperkalemia and AKI than steroidal MRAs with a smaller effect on systolic blood pressure, greatly expanding its therapeutic utility. The recently published FIGARO-DKD and FIDELIO-DKD trials demonstrate that treatment with finerenone in patients with type II diabetes and albuminuric CKD results in improved cardiovascular outcomes and a lower risk of CKD progression. Patients enrolled in these studies were already on maximally tolerated ACE inhibitor or angiotensin receptor blocker therapy. Trials investigating finerenone's therapeutic effect in patients with heart failure with preserved ejection fraction (HFpEF) and non-diabetic CKD, as well sodium-glucose cotransporter 2 (SGLT2) and finerenone combination therapy in patients with diabetic nephropathy, are ongoing.

Temporal relationship between systemic endothelial dysfunction and alterations in erythrocyte function in a murine model of chronic heart failure

Aims

Endothelial dysfunction (ED) and red blood cell distribution width (RDW) are both prognostic factors in heart failure (HF), but the relationship between them is not clear. In this study, we used a unique mouse model of chronic HF driven by cardiomyocyte-specific overexpression of activated Gαq protein (Tgαq*44 mice) to characterize the relationship between the development of peripheral ED and the occurrence of structural nanomechanical and biochemical changes in red blood cells (RBCs).

Methods and results

Systemic ED was detected in vivo in 8-month-old Tgαq*44 mice, as evidenced by impaired acetylcholine-induced vasodilation in the aorta and increased endothelial permeability in the brachiocephalic artery. ED in the aorta was associated with impaired nitric oxide (NO) production in the aorta and diminished systemic NO bioavailability. ED in the aorta was also characterized by increased superoxide and eicosanoid production. In 4- to 6-month-old Tgαq*44 mice, RBC size and membrane composition displayed alterations that did not result in significant changes in their nanomechanical and functional properties. However, 8-month-old Tgαq*44 mice presented greatly accentuated structural and size changes and increased RBC stiffness. In 12-month-old Tgαq*44 mice, the erythropathy was featured by severely altered RBC shape and elasticity, increased RDW, impaired RBC deformability, and increased oxidative stress (gluthatione (GSH)/glutathione disulfide (GSSG) ratio). Moreover, RBCs taken from 12-month-old Tgαq*44 mice, but not from 12-month-old FVB mice, coincubated with aortic rings from FVB mice, induced impaired endothelium-dependent vasodilation and this effect was partially reversed by an arginase inhibitor [2(S)-amino-6-boronohexanoic acid].

Conclusion

In the Tgαq*44 murine model of HF, systemic ED accelerates erythropathy and, conversely, erythropathy may contribute to ED. These results suggest that erythropathy may be regarded as a marker and a mediator of systemic ED in HF. RBC arginase and possibly other RBC-mediated mechanisms may represent novel therapeutic targets for systemic ED in HF.

Association of long-term SBP with clinical outcomes and quality of life in heart failure with preserved ejection fraction: an analysis of the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist trial

AIMS

To determine the associations of long-term SBP (LT-SBP) levels with clinical outcomes and health-related quality of life in heart failure with preserved ejection fraction (HFpEF).

METHODS AND RESULTS

We analyzed participants from the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) study with available different SBP measurements from different follow-ups (n = 3310). LT-SBP was the mean SBP value from 4-week measurement to the last one. The outcome measures are all-cause mortality and a composite of heart failure readmission or all-cause mortality and the Kansas City Cardiomyopathy Questionnaire (KCCQ) overall summary score. To determine the associations of LT-SBP and outcomes, we used adjusted Cox proportional hazards models and restricted cubic spline models. After multivariable adjustment, LT-SBP of 120-129 and 130-139 mmHg were associated with a lower risk of mortality (hazard ratio 0.66, 95% CI 0.51-0.87, P = 0.003; hazard ratio 0.68, 95% CI 0.51-0.90, P = 0.007, respectively); LT-SBP of 100-119 mmHg had similar risk of mortality (hazard ratio 0.96, 95% CI 0.72-1.28, P = 0.778) compared with LT-SBP of at least 140 mmHg. There was U-shaped relationship between LT-SBP and all-cause mortality (P < 0.001) with nadir risk occurring around 123 mmHg. Similar relationships were observed between LT-SBP and composite end point of heart failure readmission or all-cause mortality. The adjusted mean improvement in KCCQ score was significantly higher in the 120-129 mmHg group than in the at least 140 mmHg group beginning from the 12-month follow-up visit without significant differences in other groups.

CONCLUSION

Among patients with HFpEF, long-term control of SBP level at 120-129 mmHg is independently associated with the highest risk reduction of all-cause mortality and improvement of KCCQ score. Future randomized clinical trials need to specifically evaluate optimal SBP treatment goals in patients with HFpEF.

Hypertension and heart failure with preserved ejection fraction: position paper by the European Society of Hypertension

Hypertension constitutes a major risk factor for heart failure with preserved ejection fraction (HFpEF). HFpEF is a prevalent clinical syndrome with increased cardiovascular morbidity and mortality. Specific guideline-directed medical therapy (GDMT) for HFpEF is not established due to lack of positive outcome data from randomized controlled trials (RCTs) and limitations of available studies. Although available evidence is limited, control of blood pressure (BP) is widely regarded as central to the prevention and clinical care in HFpEF. Thus, in current guidelines including the 2018 European Society of Cardiology (ESC) and European Society of Hypertension (ESH) Guidelines, blockade of the renin-angiotensin system (RAS) with either angiotensin-converting enzyme inhibitors or angiotensin receptor blockers provides the backbone of BP-lowering therapy in hypertensive patients. Although superiority of RAS blockers has not been clearly shown in dedicated RCTs designed for HFpEF, we propose that this core drug treatment strategy is also applicable for hypertensive patients with HFpEF with the addition of some modifications. The latter apply to the use of spironolactone apart from the treatment of resistant hypertension and the use of the angiotensin receptor neprilysin inhibitor. In addition, novel agents such as sodium-glucose co-transporter-2 inhibitors, currently already indicated for high-risk patients with diabetes to reduce heart failure hospitalizations, and finerenone represent promising therapies and results from ongoing RCTs are eagerly awaited. The development of an effective and practical classification of HFpEF phenotypes and GDMT through dedicated high-quality RCTs are major unmet needs in hypertension research and calls for action.

Renin-angiotensin system overactivation in perivascular adipose tissue contributes to vascular dysfunction in heart failure

Perivascular adipose tissue (PVAT) dysfunction is associated with vascular damage in cardiometabolic diseases. Although heart failure (HF)-induced endothelial dysfunction is associated with renin-angiotensin system (RAS) activation, no data have correlated this syndrome with PVAT dysfunction. Thus, the aim of the present study was to investigate whether the hyperactivation of the RAS in PVAT participates in the vascular dysfunction observed in rats with HF after myocardial infarction surgery. Wire myograph studies were carried out in thoracic aorta rings in the presence and absence of PVAT. An anticontractile effect of PVAT was observed in the rings of the control rats in the presence (33%) or absence (11%) of endothelium. Moreover, this response was substantially reduced in animals with HF (5%), and acute type 1 angiotensin II receptor (AT1R) and type 2 angiotensin II receptor (AT2R) blockade restored the anticontractile effect of PVAT. In addition, the angiotensin-converting enzyme 1 (ACE1) activity (26%) and angiotensin II levels (51%), as well as the AT1R and AT2R gene expression, were enhanced in the PVAT of rats with HF. Associated with these alterations, HF-induced lower nitric oxide bioavailability, oxidative stress and whitening of the PVAT, which suggests changes in the secretory function of this tissue. The ACE1/angiotensin II/AT1R and AT2R axes are involved in thoracic aorta PVAT dysfunction in rats with HF. These results suggest PVAT as a target in the pathophysiology of vascular dysfunction in HF and provide new perspectives for the treatment of this syndrome.

Modification of ventriculo-arterial coupling by spironolactone in nonischemic dilated cardiomyopathy

Aims

We sought to clarify the role of ventriculo–arterial (V–A) coupling in the treatment of nonischemic dilated cardiomyopathy (NIDCM) by adding a mineralocorticoid receptor antagonist (MRA) to conventional anti‐failure therapy.

Methods and results

We employed cardiac magnetic resonance imaging to quantify left ventricular (LV) contractility and V–A coupling in normal subjects at rest (n = 11) and in patients with NIDCM (n = 12) before and after long term anti‐failure therapy, in which MRA was added to conventional anti‐failure therapy. After ≥6 months' treatment in NIDCM patients, LV volumes and mass decreased, and the LV ejection fraction increased from a median of 24% (17, 27) (interquartile range IQR) to 47 (42, 52) (P < 0.002), with a marked reduction in arterial elastance (Ea) from 2.89 mmHg/mL (2.34, 4.0) to 1.50 (1.29, 1.95) (P < 0.002), similar to Ea of normal subjects, 1.53 (1.34, 1.67) (P > 0.05). The V–A coupling ratio, Ea/end‐systolic elastance (single‐beat method), decreased by −1.08 (−1.96, −0.55), (P = 0.003), as did Ea/end‐systolic pressure/end‐systolic pressure ratio, −0.54 (0.35, 0.87), (P = 0.002). The preload recruitable stroke work (PRSW) increased as did PRSW indexed for Ea (both P = 0.002), which reflected ‘total circulatory performance’.

Conclusions

In NIDCM, adding MRA to conventional anti‐failure therapy markedly improved LV ejection fraction and reduced peripheral vascular resistance, due to both improved LV contractility and especially to enhanced V–A coupling, as Ea decreased to normal. Total circulatory performance was a sensitive indicator of both LV pump performance and the arterial loading conditions.

The Role of Natural Killer (NK) Cells in Acute Coronary Syndrome: A Comprehensive Review

With poor outcomes and an immense financial burden, acute coronary syndrome (ACS) and its ischemic repercussions still present a major global health problem. Unfavorable outcomes seem to be mainly due to adverse cardiac remodeling. Since the inflammatory response takes an important role in remodeling secondary to myocardial infarction (MI), and as inflammation in this manner has not been completely elucidated, we attempted to give rise to a further understanding of ACS pathophysiology. Hence, in this review, we integrated current knowledge of complex communication networks between natural killer (NK) cells and immune and resident heart cells in the context of ACS. Based on available data, the role of NK cells seems to be important in the infarcted myocardium, where it affects heart remodeling. On the other hand, in atherosclerotic plaque, NK cells seem to be mere passers-by, except in the case of chronic infections by atherogenic pathogens. In that case, NK cells seem to support proinflammatory milieu. NK cell research is challenging due to ethical reasons, convergent evolution, and phenotypic diversity among individuals. Therefore, we argue that further research of NK cells in ACS is valuable, given their therapeutic potential in improving postischemic heart remodeling.

Microvascular Dysfunction in Heart Failure With Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is an increasingly studied entity accounting for 50% of all diagnosed heart failure and that has claimed its own dignity being markedly different from heart failure with reduced EF in terms of etiology and natural history (Graziani et al., 2018). Recently, a growing body of evidence points the finger toward microvascular dysfunction as the major determinant of the pathological cascade that justifies clinical manifestations (Crea et al., 2017). The high burden of comorbidities such as metabolic syndrome, hypertension, atrial fibrillation, chronic kidney disease, obstructive sleep apnea, and similar, could lead to a systemic inflammatory state that impacts the physiology of the endothelium and the perivascular environment, engaging complex molecular pathways that ultimately converge to myocardial fibrosis, stiffening, and dysfunction (Paulus and Tschope, 2013). These changes could even self-perpetrate with a positive feedback where hypoxia and locally released inflammatory cytokines trigger interstitial fibrosis and hypertrophy (Ohanyan et al., 2018). Identifying microvascular dysfunction both as the cause and the maintenance mechanism of this condition has opened the field to explore specific pharmacological targets like nitric oxide (NO) pathway, sarcomeric titin, transforming growth factor beta (TGF-β) pathway, immunomodulators or adenosine receptors, trying to tackle the endothelial impairment that lies in the background of this syndrome (Graziani et al., 2018;Lam et al., 2018). Yet, many questions remain, and the new data collected still lack a translation to improved treatment strategies. To further elaborate on this tangled and exponentially growing topic, we will review the evidence favoring a microvasculature-driven etiology of this condition, its clinical correlations, the proposed diagnostic workup, and the available/hypothesized therapeutic options to address microvascular dysfunction in the failing heart.

Role of spironolactone in the treatment of heart failure with preserved ejection fraction

Heart failure (HF) is the leading cause of morbidity and mortality globally. Heart failure with preserved ejection fraction (HFpEF) is currently responsible for about half of the patients affected with HF and is associated with impaired functional capacity, as well as significant morbidity due to frequent hospitalizations. Unfortunately, despite its poor prognosis, the management of HFpEF is very controversial and no therapy has been so far shown to reduce mortality in HFpEF. Spironolactone antagonizes the effect of aldosterone and can lead to a reduction in fibrosis and an improvement in left ventricular (LV) function. Furthermore, spironolactone decreases extracellular matrix turnover and myocardial collagen content and improves endothelial vasomotor dysfunction, mechanisms known to influence the progression of HF. Thus, given the aforementioned beneficial actions of spironolactone, extensive research has been conducted to explore the effects of spironolactone on HFpEF. Our review aims to present and discuss the clinical and scientific data pertaining to the role of spironolactone in the treatment of patients with HFpEF.

Acylated ghrelin protects aorta damage post-MI via activation of eNOS and inhibition of angiotensin-converting enzyme induced activation of NAD(P)H-dependent oxidase

NAD(P)H dependent oxidase derived-reactive oxygen species (ROS) due to activation of the renin-angiotensin-aldosterone system (RAAS) in blood vessels postmyocardial infarction MI or during the HF leads to endothelium dysfunction and enhanced apoptosis. Acylated ghrelin (AG) is a well-reported cardioprotective and antiapoptotic agent for the heart. AG receptors are widely distributed in most of blood vessels, suggesting a role in the regulation of endothelial function and survival. This study investigated if AG can protect aorta of rats' postmyocardial infarction (MI)-induced damage and endothelial dysfunction. Adult male rats were divided into four groups of (1) Sham, (2) Sham + AG, (3) MI, and (4) MI + AG. Vehicle (normal saline) or AG (100 µ/kg) was administered to rats for 21 consecutive days, after which, numerous biochemical markers were detected by blot. Both histological and electron microscope studies were carried on aortic samples from MI-induced rats. AG increased protein levels of both total and phosphorylated forms of endothelial nitric oxide synthase (eNOS and p-eNOS, respectively). Only in MI-treated rats, AG prevented the decreases in the levels of reduced glutathione (GSH) and superoxide dismutase (SOD) and lowered levels of malondialdehyde (MDA) and glutathione disulfide (GSSG). Concomitantly, it lowered the increased protein levels of angiotensin-converting enzyme (ACE), p22phox and cleaved caspase-3 and prevented the aorta histological and ultrustructural abnormalities induced by MI.

Obstacles to mineralocorticoid receptor antagonists in a community-based heart failure population

AIM

Previous studies and national assessments indicate an undertreatment of mineralocorticoid receptor antagonists (MRA) in heart failure with reduced ejection fraction (HFrEF). This study aimed to investigate why MRA is not used to full extent.

METHODS

A complete community-based heart failure population was studied. Several variables were collected, and medical records were scrutinized to identify reasons for not prescribing MRA.

RESULTS

Of 2029 patients, 812 had EF ≤40%. Five hundred and fifty-three patients (68%) tried MRA at some point but 184 of these (33%) discontinued therapy. There were 259 patients that never tried MRA with 177 with a listed explanation or contraindication. Eighty-two patients, 10% of the total HFrEF population, had no clear contraindications. They were older and had less HF hospitalizations compared to patients on MRA (P < 0.05) and 32% did not have any follow-up at the cardiology clinic. Contraindications to MRA were renal dysfunction (93 patients), hypotension (28 patients), and hyperkalemia (25 patients). Only six patients had hyperkalemia without renal dysfunction. Of the patients with renal dysfunction, 66 (72%) had eGFR >30 mL/min.

CONCLUSIONS

The reasons why MRA are underutilized were mainly because of contraindications. However, the data suggest that physicians are overly cautious about moderately reduced kidney function. There seems to be a 10%-18% avoidable undertreatment with MRA, especially for elderly patients that are admitted to the hospital for other reasons than heart failure. This suggests that patients with heart failure would benefit from routine follow-up at a cardiology clinic.

Evidence for the use of mineralocorticoid receptor antagonists in the treatment of coronary artery disease and post-angioplasty restenosis

Mineralocorticoid receptor antagonists (MRAs), such as spironolactone and eplerenone have an established role in the treatment of heart failure. However, many experimental and clinical studies have shown that aldosterone also plays a pivotal role in a variety of other pathophysiological conditions within the cardiovascular system. Aldosterone has been suggested to promote inflammation, endothelial dysfunction and smooth muscle cell hyperplasia during the development of atherosclerosis, thereby promoting the development of coronary artery disease (CAD). Since CAD and subsequent ischemic cardiomyopathy are the major causes of heart failure, it is of major interest, whether pharmacological therapy with MRAs among heart failure patients will also affect the common underlying conditions, namely, atherosclerosis and subsequent coronary vessel narrowing/rarefication. Therefore, in this article, we reviewed and discussed the preclinical and clinical evidence of MRAs for the treatment of acute or chronic vascular remodeling processes, such as atherosclerosis and post-angioplasty restenosis, which determine the progression of CAD and subsequent ischemic cardiomyopathy.

Does Aldosterone Play a Significant Role for Regulation of Vascular Tone?

Besides the well-known renal effects of aldosterone, the hormone is now known to have direct vascular effects. Clinical observations underline substantial adverse effects of aldosterone on cardiovascular function. The source of systemic circulating aldosterone is the adrenal gland zona glomerulosa cells through stimulus-secretion coupling involving depolarization, opening of L- and T-type calcium channels and aldosterone synthase activation. Local formation and release in peripheral tissues such as perivascular fat is recognized. Where does aldosterone affect the vasculature? Mineralocorticoid receptors (MRs) are present in endothelial and vascular smooth muscle cells, and MR-independent pathways are also involved. The vascular effects of aldosterone are complex, both concentration and temporal and spatial aspects are relevant. The acute response includes vasodilation through endothelial nitric oxide formation and vasoconstrictor effects through endothelial-contracting cyclooxygenase-derived factors and a changed calcium handling. The response to aldosterone can change within the same blood vessels depending on the exposure time and status of the endothelium. Chronic responses involve changed levels of reactive oxygen radicals, endothelial Na-influx and smooth muscle calcium channel expression. Furthermore, perivascular cells for example mast cells have also been suggested to participate in the chronic response. Moreover, the vascular effect of aldosterone depends on the status of the endothelium which is likely the cause of the very different responses to aldosterone and MR treatment observed in human studies going from increased to decreased flow depending on whether the patient had prior cardiovascular disease with endothelial dysfunction or not. A preponderance of constrictor versus dilator responses to aldosterone could therefore be involved in the detrimental vascular actions of the hormone in the setting of endothelial dysfunction and contribute to explain the beneficial action of MR blockers on blood pressure and target organ injury.

Endothelial dysfunction in cardiovascular disease and Flammer syndrome-similarities and differences

The endothelium has increasingly been recognized as a smart barrier and a key regulator of blood flow in micro- and macrovascular beds. Endothelial dysfunction marks a stage of atherosclerosis and is an important prognostic marker for cardiovascular disease. Yet, some people who tend to be slim and physically active and with rather low blood pressure show a propensity to respond to certain stimuli such as emotional stress with endothelial-mediated vascular dysregulation (Flammer syndrome). This leads to characteristic vascular symptoms such as cold hands but also a risk for vascular-mediated diseases such as normal-tension glaucoma. It is the aim of this review to delineate the differences between Flammer syndrome and its "counterpart" endothelial dysfunction in the context of cardiovascular diseases.

[Cardiac remodeling after myocardial infarction : Clinical practice update]

Heart failure remains a frequent cause of death and is the leading reason for hospitalization in Germany although therapeutic options have significantly increased over the past years particularly in heart failure with reduced ejection fraction. Clinical symptoms are usually preceded by cardiac remodeling, which was originally defined only by left ventricular dilatation and depressed function but is also associated with typical cellular and molecular processes. Healing after acute myocardial infarction is characterized by inflammation, cellular migration and scar formation. Cardiac remodeling is accompanied by adaptive changes of the peripheral cardiovascular system. Since prevention is the primary goal, rapid diagnosis and treatment of myocardial infarction are mandatory. Early reperfusion therapy limits infarct size and enables the best possible preservation of left ventricular function. Standard pharmacotherapy includes angiotensin-converting enzyme inhibitors, angiotensin-1-receptor blockers and beta blockers. In addition, mineralocorticoid receptor antagonists have proven beneficial. Compounds specifically targeting infarct healing processes are currently under development.

Mineralocorticoid Receptor Antagonists for Treatment of Hypertension and Heart Failure

Spironolactone and eplerenone are both mineralocorticoid-receptor antagonists. These compounds block both the epithelial and nonepithelial actions of aldosterone, with the latter assuming increasing clinical relevance. Spironolactone and eplerenone both affect reductions in blood pressure either as mono- or add-on therapy; moreover, they each afford survival benefits in diverse circumstances of heart failure and the probability of renal protection in proteinuric chronic kidney disease. However, as use of mineralocorticoid-blocking agents has expanded, the hazards inherent in taking such drugs have become more apparent. Whereas the endocrine side effects of spironolactone are in most cases little more than a cosmetic annoyance, the potassium-sparing effects of both spironolactone and eplerenone can prove disastrous, even fatal, if sufficient degrees of hyperkalemia emerge. For most patients, however, the risk of developing hyperkalemia in and of itself should not discourage the sensible clinician from bringing these compounds into play. Hyperkalemia should always be considered a possibility in patients receiving either of these medications; therefore, anticipatory steps should be taken to minimize the likelihood of its occurrence if long-term therapy of these agents is being considered.

Toward a broader understanding of aldosterone in congestive heart failure

Discovered some 50 years ago, aldosterone (ALDO) has come to be recognised as a mineralocorticoid hormone with well-known endocrine properties in epithelial cells that contribute to the pathophysiology of congestive heart failure. This includes Na + resorption at the expense of K+ excretion in classic target tissues: kidneys, colon, sweat and salivary glands. Though less well known, Mg2+ excretion is likewise enhanced by ALDO, while adrenal ALDO secretion is regulated by extracellular Mg2+ ([Mg2+ ]o). An emerging body of information has and continues to identify other endocrine actions of ALDO receptor-ligand binding. They include: promoting an efflux of cytosolic free Mg2+, or [Mg2+]i, in exchange for Na+ in such non-epithelial cells as peripheral blood mononuclear cells; its influence on endothelial cell function; and its central actions that involve regulation of cerebrospinal fluid composition produced by epithelial cells of the choroid plexus, activity of the hypothalamic paraventricular nucleus involved in Na+ appetite, Na+ and H2O excretion and sympathetic nerve activity, and the regulation of TNF-α production from central and/or peripheral sources. Extra-adrenal steroidogenesi and auto/paracrine properties of ALDO generated de novo in the cardiovasculature are now under investigation and preliminary findings suggest they contribute to tissue repair. The past decade has witnessed a revival of interest in this steroid molecule. In years to come, an even broader understanding of ALDO's contribution to the pathophysiology of congestive heart failure will undoubtedly emerge.

Combination of drugs acting on the natriuretic system and the renin-angiotensin system in heart failure

Conventional diuretic agents are very effective agents in relieving volume overload and congestive symptoms in chronic heart failure (CHF). However, they are associated with activation of the renin-angiotensin system (RAS) and the sympathetic nervous system and a reduction in glomerular filtration rate, all of which have been associated with adverse outcomes in CHF. Therefore, there is an increasing interest in drugs that target the natriuretic system without neurohormonal activation and deterioration of renal function. In this review, we will discuss the underlying rationale and evidence behind currently pursued strategies that target the natriuretic system. This includes the administration of natriuretic peptides (NPs) and strategies that potentiate the NP system, such as neutral endopeptidase inhibition. We will also highlight some potentially important interactions of these strategies with drugs that target the RAS.

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.

Gender-specific association between urinary sodium excretion and body composition: Analysis of the 2008-2010 Korean National Health and Nutrition Examination Surveys

OBJECTIVE

Few studies have reported the relationship between sarcopenia and the estimated amount of sodium excreted in 24 h, as measured by the spot urine test (E24UNA), in a community-dwelling cohort. We investigated the gender specific association between E24UNA values and body composition indices.

MATERIALS AND METHODS

Data from a total of 7162 participants (3545 men and 3617 postmenopausal women) aged 45 years or older were obtained from multiple Korea National Health and Nutrition Examination Surveys (2008-2010) and analyzed. The total amount of sodium excreted in the urine in a 24-h period was estimated with spot urine specimens. Sarcopenia was defined as an appendicular skeletal muscle mass divided by body weight (ASM/Wt) that was less than 1 standard deviation below the sex-specific mean for young adults.

RESULTS

E24UNA values were positively correlated with body mass index, waist circumference, total fat mass, and blood pressure; in contrast, E24UNA values were negatively correlated with ASM/Wt in both sexes. Compared with those in the lowest E24UNA tertile, participants in the highest E24UNA tertile were at higher risk for sarcopenia (men: odds ratio (OR)=1.3 [95% confidence interval (CI)=1.07-1.59]; women: OR=1.41 [95% CI=1.16-1.73]). Further classification of subjects with sarcopenia into sarcopenic obese and sarcopenic nonobese groups revealed that the highest E24UNA values were found in the sarcopenic obese group; this difference was statistically significant. The next highest levels were found in the sarcopenic nonobese group, followed by the nonsarcopenic group. This trend was observed in both sexes.

CONCLUSION

High E24UNA values were independently associated with both sarcopenia and obesity in Korean individuals older than 45 years. These results suggest that high salt intake may have a deleterious effect on body composition.

Heart failure and mitochondrial dysfunction: the role of mitochondrial fission/fusion abnormalities and new therapeutic strategies

The treatment of heart failure (HF) has evolved during the past 30 years with the recognition of neurohormonal activation and the effectiveness of its inhibition in improving the quality of life and survival. Over the past 20 years, there has been a revolution in the investigation of the mitochondrion with the development of new techniques and the finding that mitochondria are connected in networks and undergo constant division (fission) and fusion, even in cardiac myocytes. This has led to new molecular and cellular discoveries in HF, which offer the potential for the development of new molecular-based therapies. Reactive oxygen species are an important cause of mitochondrial and cellular injury in HF, but there are other abnormalities, such as depressed mitochondrial fusion, that may eventually become the targets of at least episodic treatment. The overall need for mitochondrial fission/fusion balance may preclude sustained change in either fission or fusion. In this review, we will discuss the current HF therapy and its impact on the mitochondria. In addition, we will review some of the new drug targets under development. There is potential for effective, novel therapies for HF to arise from new molecular understanding.

Spironolactone improves endothelial dysfunction in streptozotocin-induced diabetic rats

Endothelial dysfunction is a critical initiator for developing diabetic vascular complications. Substantial clinical and experimental evidence suggests that aldosterone plays a crucial role in its pathogenesis. The present study aimed to investigate the effect of the mineralocorticoid receptor (MR) blocker, spironolactone, on diabetes-associated endothelial dysfunction and address the underlying mechanism(s) involved in this setting. Diabetes was induced by a single intraperitoneal injection of streptozotocin (STZ) to rats and spironolactone was orally administered (50 mg/kg/day). Our results showed a marked increase in aortic malondialdehyde (MDA) level and upregulation of the catalytic NADPH oxidase subunit, NOX2 gene expression alongside reducing catalase enzyme capacity, and the serum nitric oxide (NO) bioavailability in diabetic rats. This was associated with a significant reduction in endothelial nitric oxide synthase (eNOS) immunoreactivity and gene expression in diabetic aorta. The transforming growth factor-β (TGF-β) protein and the MR gene expression levels were significantly increased in the diabetic rat aorta. Moreover, the diabetic aorta showed a marked impairment in acetylcholine-mediated endothelium-dependent relaxation. Additionally, spironolactone significantly inhibited the elevated MDA, TGF-β, NOX2, and MR levels alongside correcting the dysregulated eNOS expression and the defective antioxidant function as well as NO bioavailability. Spironolactone markedly reversed the impaired endothelial function in the diabetic aorta. Collectively, our study demonstrates that spironolactone ameliorated the vascular dysfunction of diabetic aorta, at least partially via its anti-inflammatory and anti-oxidative effects alongside correcting the dysregulated eNOS and TGF-β expression. Thus, blockade of MR may represent a useful therapeutic approach against diabetic vasculopathy.

Endothelial dysfunction in patients with primary aldosteronism: a biomarker of target organ damage

Primary aldosteronism (PA) has been associated with increased target organ damage (TOD), most likely through mineralocorticoid receptor-dependent endothelial dysfunction, in comparison with essential hypertension (EH). The aim of this study was to evaluate the level of biomarkers of endothelial dysfunction in PA and the relationship with left ventricular hypertrophy (LVH) and microalbuminuria (MAU). A total of 50 PA patients and 51 patients with EH individually matched for age, sex, blood pressure and duration of hypertension participated in this study. Biomarkers of endothelial dysfunction, including von Willebrand factor (vWF), intercellular adhesion molecule 1 (ICAM-1) and oxidized low-density lipoprotein (ox-LDL), were measured. Plasma aldosterone concentration (PAC), MAU and echocardiography were also evaluated. In PA patients, vWF, ICAM-1, ox-LDL, LVH and MAU were all significantly higher than in EH patients (all P<0.05). Furthermore, LVH was positively correlated with PAC (P=0.002), vWF (P=0.013) and ox-LDL (P=0.020). MAU was positively correlated with PAC (P<0.001), vWF (P=0.013) and ICAM-1 (P=0.001). Multiple regression analysis indicated that vWF, ICAM-1 and PAC independently predicted MAU (all P<0.05). Likewise, PAC, vWF and ox-LDL were significant predictors of LVH (all P<0.05). Taken together, our results suggest that endothelial dysfunction may contribute to TOD in PA patients.

Aldosterone affects blood flow and vascular tone regulated by endothelium-derived NO: therapeutic implications

Aldosterone, in doses inappropriate to the salt status, plays an important role in the development of cardiovascular injury, including endothelial dysfunction, independent of its hypertensive effects. Acute non-genomic effects of aldosterone acting on mineralocorticoid receptors are inconsistent in healthy humans: vasoconstriction or forearm blood flow decrease via endothelial dysfunction, vasodilatation mediated by increased NO actions, or no effects. However, in studies with experimental animals, aldosterone mostly enhances vasodilatation mediated by endothelium-derived NO. Chronic exposure to aldosterone, which induces genomic responses, results in impairments of endothelial function through decreased NO synthesis and action in healthy individuals, experimental animals and isolated endothelial cells. Chronic aldosterone reduces NO release from isolated human endothelial cells only when extracellular sodium is raised. Oxidative stress is involved in the impairment of endothelial function by promoting NO degradation. Aldosterone liberates endothelin-1 (ET-1) from endothelial cells, which elicits ET(A) receptor-mediated vasoconstriction by inhibiting endothelial NO synthesis and action and through its own direct vasoconstrictor action. Ca(2+) flux through T-type Ca(2+) channels activates aldosterone synthesis and thus enhances unwanted effects of aldosterone on the endothelium. Mineralocorticoid receptor inhibitors, ET(A) receptor antagonists and T-type Ca(2) + channel blockers appear to diminish the pathophysiological participation of aldosterone in cardiovascular disease and exert beneficial actions on bioavailability of endothelium-derived NO, particularly in resistant hypertension and aldosteronism.

Endothelial dysfunction, arterial stiffness, and heart failure

Outcomes for heart failure (HF) patients remain suboptimal. No known therapy improves mortality in acute HF and HF with preserved ejection fraction; the most recent HF trial results have been negative or neutral. Improvement in surrogate markers has not necessarily translated into better outcomes. To translate breakthroughs with potential therapies into clinical benefit, a better understanding of the pathophysiology establishing the foundation of benefit is necessary. Vascular function plays a central role in the development and progression of HF. Endothelial function and nitric oxide availability affect myocardial function, systemic and pulmonary hemodynamics, and coronary and renal circulation. Arterial stiffness modulates ventricular loading conditions and diastolic function, key components of HF with preserved ejection. Endothelial function and arterial stiffness may therefore serve as important physiological targets for new HF therapies and facilitate patient selection for improved application of existing agents.

Rationale and design of the treatment of preserved cardiac function heart failure with an aldosterone antagonist trial: a randomized, controlled study of spironolactone in patients with symptomatic heart failure and preserved ejection fraction

BACKGROUND

Despite increasing prevalence of heart failure (HF) in patients with preserved ejection fraction (PEF), there are no available therapies proven to reduce morbidity and mortality. Aldosterone, a potent stimulator of myocardial and vascular fibrosis, may be a key mediator of HF progression in this population and is therefore an important therapeutic target.

OBJECTIVE

The TOPCAT trial is designed to evaluate the effect of spironolactone, an aldosterone antagonist, on morbidity, mortality, and quality of life in patients with HF-PEF.

METHODS

Up to 3,515 patients with HF-PEF will be randomized in double-blind fashion to treatment with spironolactone (target dose 30 mg daily) or matching placebo. Eligible patients include those with age ≥50 years, left ventricular ejection fraction ≥45%, symptomatic HF, and either a hospitalization for HF within the prior year or an elevated natriuretic peptide level (B-type natriuretic peptide ≥100 pg/mL or N-terminal pro-B-type natriuretic peptide ≥360 pg/mL) within the 60 days before randomization. Patients with uncontrolled hypertension and those with known infiltrative or hypertrophic cardiomyopathy are excluded. The primary end point is the composite of cardiovascular death, hospitalization for HF, or aborted cardiac arrest. Key secondary end points include quality of life, nonfatal cardiovascular events, and new-onset atrial fibrillation. Ancillary studies of echocardiography, tonometry, and cardiac biomarkers will provide more insight regarding this understudied population and the effects of spironolactone therapy.

CONCLUSION

TOPCAT is designed to assess definitively the role of spironolactone in the management of HF-PEF.

Mineralocorticoid antagonism: a novel way to treat sarcopenia and physical impairment in older people?

Dysregulation of the renin-angiotensin-aldosterone system has been associated with a number of age-related pathologies including hypertension, heart failure and chronic kidney disease. More recently, it has been suggested that alterations within the RAAS may contribute to the development of sarcopenia and subsequent decline in physical function. There is growing interest in developing interventions to prevent age-associated decline in muscle function. We postulate that inhibition of the RAAS with the mineralocorticoid antagonist spironolactone may have a role in countering the effects of physical impairment in older people by improving skeletal muscle function. Spironolactone may prevent skeletal myocyte apoptosis, improve vascular endothelial function and enhance muscle contractility by increasing muscle magnesium and sodium-potassium pumps. This article will review the literature underpinning the hypothesis that spironolactone may have a role in maintaining muscle function in older people.

Coronary endothelial dysfunction after cardiomyocyte-specific mineralocorticoid receptor overexpression

The deleterious effects of aldosterone excess demonstrated in cardiovascular diseases might be linked in part to coronary vascular dysfunction. However, whether such vascular dysfunction is a cause or a consequence of the changes occurring in the cardiomyocytes is unclear. Moreover, the possible link between mineralocorticoid receptor (MR)-mediated effects on the cardiomyocyte and the coronary arteries is unknown. Thus we used a mouse model with conditional, cardiomyocyte-specific overexpression of human MR (hMR) and observed the effects on endothelial function in isolated coronary segments. hMR overexpression decreased the nitric oxide (NO)-mediated relaxing responses to acetylcholine in coronary arteries (but not in peripheral arteries), and this was prevented by a 1-mo treatment either with an MR antagonist, vitamin E/vitamin C, or a NADPH oxidase inhibitor. hMR overexpression did not affect coronary endothelial NO synthase content nor its level of phosphorylation on serine 1177, but increased cardiac levels of reactive oxygen species, cardiac NADPH oxidase (NOX) activity, and expression of the NOX subunit gp91phox, which was limited to endothelial cells. Thus an increase in hMR activation, restricted to cardiomyocytes, is sufficient to induce a severe coronary endothelial dysfunction. We suggest a new paracrine mechanism by which cardiomyocytes trigger a NOX-dependent, reactive oxygen species-mediated coronary endothelial dysfunction.

Study of the mechanisms of aldosterone prothrombotic effect in rats

INTRODUCTION

We investigated the role of primary haemostasis, fibrinolysis, nitric oxide (NO) and oxidative stress as well as mineralocorticoid receptors (MR) in acute aldosterone prothrombotic action.

MATERIALS AND METHODS

Venous thrombosis was induced by stasis in Wistar rats. Aldosterone (ALDO; 10, 30, 100 µg/kg/h) was infused for 1 h. Eplerenone (EPL; 100 mg/kg, p.o.), a selective MR antagonist, was administered before ALDO infusion. Bleeding time (BT) and platelet adhesion to collagen were evaluated. The expression of nitric oxide synthase (NOS), NADPH oxidase, superoxide dismutase (SOD) and plasminogen activator inhibitor (PAI-1) was measured. NO, malonyl dialdehyde (MDA) and hydrogen peroxide (H(2)O(2)) plasma levels were assayed.

RESULTS

Significant enhancement of venous thrombosis was observed after ALDO infusion. ALDO shortened BT and increased platelet adhesion. Marked increases were observed in PAI-1, NADPH oxidase and SOD mRNA levels. MDA and H(2)O(2) levels were augmented in ALDO-treated groups, and NOS expression and NO level were decreased. EPL reduced ALDO effects on thrombus formation, primary haemostasis, PAI-1 expression and MDA level.

CONCLUSION

Short-term ALDO infusion enhances experimental venous thrombosis in the mechanism involving primary haemostasis, fibrinolysis, NO and oxidative stress-dependent pathways. The MR antagonist only partially diminished the ALDO effects, suggesting the involvement of additional mechanisms.

Aldosterone Antagonists in Heart Failure

Aldosterone antagonists represented by nonselective spironolactone and mineralocorticoid-selective eplerenone are approved for treatment of symptomatic heart failure with reduced systolic function. Their cardioprotective, antifibrotic, and antiarrhythmic effects have been proven in animal experiments, and their effects on morbidity and mortality have been demonstrated in randomized clinical trials. Yet, they remain the most underutilized of all classes of medications for heart failure, primarily because of fear of hyperkalemia. Thorough patient screening and selection is the key for minimizing risks and optimizing benefits from these drugs. Ongoing trials will demonstrate whether the indication for aldosterone antagonists can be expanded to less severe heart failure or patients with preserved systolic function.

Impairment of endothelial progenitor cell function and vascularization capacity by aldosterone in mice and humans

Aims

Hyperaldosteronism is associated with vascular injury and increased cardiovascular events. Bone marrow-derived endothelial progenitor cells (EPCs) play an important role in endothelial repair and vascular homeostasis. We hypothesized that hyperaldosteronism impairs EPC function and vascularization capacity in mice and humans.

Methods and results

We characterized the effects of aldosterone and mineralocorticoid receptor (MR) blockade on EPC number and function as well as vascularization capacity and endothelial function. Treatment of human EPC with aldosterone induced translocation of the MR and impaired multiple cellular functions of EPC, such as differentiation, migration, and proliferation in vitro. Impaired EPC function was rescued by pharmacological blockade or genetic ablation of the MR. Aldosterone protein kinase A (PKA) dependently increased reactive oxygen species formation in EPC. Aldosterone infusion in mice impaired EPC function, EPC homing to vascular structures and vascularization capacity in a MR-dependent but blood pressure-independent manner. Endothelial progenitor cells from patients with primary hyperaldosteronism compared with controls of similar age displayed reduced migratory potential. Impaired EPC function was associated with endothelial dysfunction. MR blockade in patients with hyperaldosteronism improved EPC function and arterial stiffness.

Conclusion

Endothelial progenitor cells express a MR that mediates functional impairment by PKA-dependent increase of reactive oxygen species. Normalization of EPC function may represent a novel mechanism contributing to the beneficial effects of MR blockade in cardiovascular disease prevention and treatment.

Aliskiren and valsartan combination therapy for the management of hypertension

Combination therapy is necessary for most patients with hypertension, and agents that inhibit the renin-angiotensin-aldosterone system (RAAS) are mainstays in hypertension management, especially for patients at high cardiovascular and renal risk. Single blockade of the RAAS with an angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) confers some cardiorenal protection; however, these agents do not extinguish the RAAS as evidenced by a reactive increase in plasma renin activity (PRA), a cardiovascular risk marker, and incomplete cardiorenal protection. Dual blockade with an ACE inhibitor and an ARB offers no additional benefit in patients with hypertension and normal renal and left ventricular function. Indeed, PRA increases synergistically with dual blockade. Aliskiren, the first direct renin inhibitor (DRI) to become available has provided an opportunity to study the merit of DRI/ARB combination treatment. By blocking the first and rate-limiting step in the RAAS, aliskiren reduces PRA by at least 70% and buffers the compensatory increase in PRA observed with ACE inhibitors and ARBs. The combination of a DRI and an ARB or an ACE inhibitor is an effective approach for lowering blood pressure; available data indicate that such combinations favorably affect proteinuria, left ventricular mass index, and brain natriuretic peptide in patients with albuminuria, left ventricular hypertrophy, and heart failure, respectively. Ongoing outcome studies will clarify the role of aliskiren and aliskiren-based combination RAAS blockade in patients with hypertension and those at high cardiorenal risk.

Rationale and design of the 'aldosterone receptor blockade in diastolic heart failure' trial: a double-blind, randomized, placebo-controlled, parallel group study to determine the effects of spironolactone on exercise capacity and diastolic function in patients with symptomatic diastolic heart failure (Aldo-DHF)

AIMS

Increasing evidence suggests that enhanced aldosterone signalling plays a key role in the onset and progression of diastolic heart failure (DHF). Aldo-DHF will test the hypothesis that aldosterone receptor blockade by spironolactone will improve exercise capacity and diastolic function in patients with DHF.

METHODS

Aldo-DHF is a randomized, placebo-controlled, double-blinded, two-armed, multicentre, parallel group study. Four hundred and twenty patients with DHF will be randomly assigned to receive spironolactone 25 mg per day or placebo. The main inclusion criteria are: age > or = 50 years, New York Heart Association II/III, preserved left ventricular ejection fraction (> or =50%), and echocardiographic evidence of diastolic dysfunction. The two primary endpoints are changes in exercise capacity (peak VO(2), spiroergometry) and in diastolic function (E/é, echocardiography) after 12 months. Secondary endpoints include effects of spironolactone on additional parameters of exercise performance and diastolic as well as systolic function, neurohumoral activation, and quality of life. Morbidity and mortality as well as safety aspects will also be assessed.

CONCLUSION

Aldo-DHF is the first large-scale clinical trial to evaluate the effects of aldosterone receptor blockade on exercise capacity and diastolic function in patients with DHF. Aldo-DHF will provide important information about the clinical course of this condition and may have significant impact on treatment strategies and future trials in these patients.

Effects of aldosterone blockade on left ventricular function and clinical status during acute myocardial infarction

OBJECTIVE

Heart failure is frequently a serious complication of acute myocardial infarction (AMI). ACE inhibitors, Angiotensin II receptor blockers, beta-blockers and aldosterone receptor blockers have been shown to improve outcomes in this setting. This study aimed to determine the effect of spironolactone on the frequency of clinical heart failure, mortality, rehospitalization and left ventricular functions determined by echocardiography.

MATERIAL AND METHODS

A total of 82 patients with STEMI hospitalized within 6-12 h of debut of symptoms were included in the study. The patients were randomly assigned into spironolactone (group A) or placebo (group B) groups after informed consent had been obtained.

RESULTS

All patients were followed for 6 months. There were no statistically significant differences between the two groups when demographic criteria were compared. The incidence of post-MI angina pectoris, rhythm and conduction disturbance during hospitalization was significantly higher in Group B than in Group A. Although not statistically significant, the incidence of clinical heart failure was slightly lower in Group A than in Group B (5% versus 11%). Left ventricular end-diastolic volumes were slightly lower in Group A than in Group B, although statistically this was not significant.

CONCLUSIONS

In concordance with these findings, the ejection fraction was slightly higher in Group A than in Group B, although this was not statistically significant (47% versus 44%). This trend continued during a 6-month follow-up after randomization. Our findings suggest that early administration of aldosterone blockers provides additional benefits after AMI, reducing the incidence of post-MI angina pectoris and rhythm and conduction disturbances.

Aldosterone and cardiovascular disease

Aldosterone is an adrenal hormone that regulates sodium, fluid, and potassium balance. Jerome Conn first described the syndrome of autonomous and excessive aldosterone secretion or "primary aldosteronism." Contrary to the historical belief, recent studies indicate that primary aldosteronism is a common cause of hypertension with a prevalence of 5-10% among general hypertensive patients. Various animal models have demonstrated that aldosterone in association with a high salt diet results in target-organ inflammation and fibrosis. Similarly, cross-sectional and observational human studies have demonstrated the association of aldosterone with development and severity of hypertension, congestive heart failure, coronary artery disease, chronic kidney disease, and metabolic syndrome. Several interventional studies have also demonstrated the beneficial effects of mineralocorticoid receptor antagonists in these disease processes, particularly hypertension, heart failure, and post myocardial infarction, further supporting the role of aldosterone in their pathogenesis. We review the role of aldosterone in these various cardiovascular disease processes along with potential mechanisms and treatment.

Endothelial dysfunction in African-Americans

The journey of atherosclerosis begins with endothelial dysfunction and culminates into its most fearful destination producing ischemia, myocardial infarction and death. The excess cardiovascular disease morbidity and mortality in African-Americans is one of the major public health problems. In this review, we discuss vascular endothelial dysfunction as a key element for excess cardiovascular disease burden in this target population. It can be logical window of future atherosclerotic outcomes, and further efforts should be made to detect it at the earliest in African American individuals even if they are appearing healthy as the therapeutic interventions if instituted early, might prevent the subsequent cardiac events.

Aldosterone synthase inhibition improves cardiovascular function and structure in rats with heart failure: a comparison with spironolactone

AIMS

Inhibition of aldosterone synthase, the key enzyme in aldosterone formation, could be an alternative strategy for mineralocorticoid-receptor antagonists in congestive heart failure (CHF), but its effect in CHF is unknown.

METHODS AND RESULTS

We compared, in rats with CHF, the effects of a 7 day and a 12 week treatment with the aldosterone synthase inhibitor FAD286 (4 mg kg(-1) day(-1)) with those induced by spironolactone (80 mg kg(-1) day(-1)). FAD286/spironolactone increased cardiac output without modifying arterial pressure. Long-term FAD286 and spironolactone reduced left ventricular (LV) end-diastolic pressure, LV relaxation constant, and LV dilatation, and these effects were more marked with FAD286, whereas both drugs reduced LV hypertrophy and collagen accumulation to the same extent. Long-term FAD286/spironolactone prevented CHF-related enhancement in LV ACE and reduction in LV ACE-2, but only FAD286 prevented the reduction in LV AT(2) receptors. FAD286, but not long-term spironolactone, reduced the CHF-related enhancements in LV reactive oxygen species, reduced-oxidized glutathione ratio, and aortic nicotinamide adenine dinucleotide phosphate oxidase activity. FAD286 normalized the CHF-induced impairment of endothelium-dependent vasodilatation.

CONCLUSION

In experimental CHF, FAD286 and spironolactone improve LV haemodynamics, remodelling, and function, but only FAD286 persistently normalizes LV 'redox status'. These results suggest that aldosterone synthase inhibition is a potential therapeutic strategy for the treatment of CHF.