Role of aldosterone in various target organ damage in patients with hypertensive emergency: a cross-sectional study

BACKGROUND

Hypertensive emergency is a critical disease that causes multiple organ injuries. Although the renin-angiotensin-aldosterone system (RAS) is enormously activated in this disorder, whether the RAS contributes to the development of the organ damage has not been fully elucidated. This cross-sectional study was conducted to characterize the association between RAS and the organ damage in patients with hypertensive emergencies.

METHODS

We enrolled 63 patients who visited our medical center with acute severe hypertension and multiple organ damage between 2012 and 2020. Hypertensive target organ damage was evaluated on admission, including severe kidney impairment (eGFR less than 30 mL/min/1.73 m2, SKI), severe retinopathy, concentric left ventricular hypertrophy (c-LVH), thrombotic microangiopathy (TMA), heart failure with reduced ejection fraction (HFrEF) and cerebrovascular disease. Then, whether each organ injury was associated with blood pressure or a plasma aldosterone concentration was analyzed.

RESULTS

Among 63 patients, 31, 37, 43 and 8 cases manifested SKI, severe retinopathy, c-LVH and ischemic stroke, respectively. All populations with the organ injuries except cerebral infarction had higher plasma aldosterone concentrations than the remaining subset but exhibited a variable difference in systolic or diastolic blood pressure. Twenty-two patients had a triad of SKI, severe retinopathy and c-LVH, among whom 5 patients manifested TMA. Furthermore, the number of the damaged organs was correlated with plasma aldosterone levels (Spearman's coefficient = 0.50), with a strong association observed between plasma aldosterone (≥ 250 pg/mL) and 3 or more complications (odds ratio = 9.16 [95%CI: 2.76-30.35]).

CONCLUSION

In patients with hypertensive emergencies, a higher aldosterone level not only contributed to the development of the organ damage but also was associated with the number of damaged organs in each patient.

Successful treatment of resistant hypertension and severe complications in a 63-year-old man with primary aldosteronism without adrenalectomy: A case report

Primary aldosteronism (PA), often due to aldosteronoma, commonly causes secondary hypertension and typically requires surgery. We present a case of an elderly man with longstanding hypertension, complicated by cerebral hemorrhage and myocardial infarction. Enhanced CT imaging identified a right-sided aldosteronoma and left adrenal gland fullness. Combined with upright supine aldosterone ratio, captopril challenge test, bilateral adrenal venous sampling, and CYP11B1/CYP11B2 fusion gene testing, the diagnosis of PA was confirmed. Despite the absence of surgical intervention in this patient, pharmacotherapy effectively managed hypertension and enhanced cardiac function, thereby underscoring the advantageous utilization of aldosterone antagonists in non-surgical candidates diagnosed with PA.

Abnormal circulating steroids refine risk of progression to heart failure in ischemic heart disease

BACKGROUND

Patients with ischemic heart disease (IHD) experience a high incidence of progression to heart failure (HF) despite current therapies. We speculated that steroid hormone metabolic disorders distinct adverse phenotypes and contribute to HF.

METHODS

We measured 18 steroids using liquid chromatography with tandem mass spectrometry in 2023 patients from the Registry Study of Biomarkers in Ischemic Heart Disease (BIOMS-IHD), including 1091 patients with IHD in a retrospective discovery set and 932 patients with IHD in a multicentre validation set. Our outcomes included incident HF after a median follow-up of 4 years.

RESULTS

We demonstrated steroid-based signatures of inflammation, coronary microvascular dysfunction and left ventricular hypertrophy that were associated with subsequent HF events in patients with IHD. In both cohorts, patients with a high steroid-heart failure score (SHFS) (>1) exhibited a greater risk of incident HF than patients with a low SHFS (≤1). The SHFS further improved the prognostic accuracy beyond clinical variables (net reclassification improvement of 0.628 in the discovery set and 0.299 in the validation set) and demonstrated the maximal effect of steroid signatures in patients with IHD who had lower B-type natriuretic peptide levels (pinteraction = 0.038).

CONCLUSIONS

A steroid-based strategy can simply and effectively identify individuals at higher HF risk who may derive benefit from more intensive follow-ups.

Differential sex-dependent susceptibility to diastolic dysfunction and arrhythmia in cardiomyocytes from obese diabetic HFpEF model

AIM

Sex-differences in heart failure with preserved ejection fraction (HFpEF) are important, but key mechanisms involved are incompletely understood. While animal models can inform about sex-dependent cellular and molecular changes, many previous preclinical HFpEF models have failed to recapitulate sex-dependent characteristics of human HFpEF. We tested for sex-differences in HFpEF using a two-hit mouse model (leptin receptor-deficient db/db mice plus aldosterone infusion for 4 weeks; db/db+Aldo).

METHODS AND RESULTS

We performed echocardiography, electrophysiology, intracellular Ca2+ imaging, and protein analysis. Female HFpEF mice exhibited more severe diastolic dysfunction in line with increased titin N2B isoform expression and PEVK element phosphorylation, and reduced troponin-I phosphorylation. Female HFpEF mice had lower BNP levels than males despite similar comorbidity burden (obesity, diabetes) and cardiac hypertrophy in both sexes. Male HFpEF mice were more susceptible to cardiac alternans. Male HFpEF cardiomyocytes (versus female) exhibited higher diastolic [Ca2+], slower Ca2+ transient decay, reduced L-type Ca2+ current, more pronounced enhancement of the late Na+ current, and increased short-term variability of action potential duration (APD). However, male and female HFpEF myocytes showed similar downregulation of inward rectifier and transient outward K+ currents, APD prolongation, and frequency of delayed afterdepolarizations. Inhibition of Ca2+/calmodulin-dependent protein kinase II (CaMKII) reversed all pathological APD changes in HFpEF in both sexes, and empagliflozin pretreatment mimicked these effects of CaMKII inhibition. Vericiguat had only slight benefits, and these effects were larger in HFpEF females.

CONCLUSION

We conclude that the db/db+Aldo preclinical HFpEF murine model recapitulates key sex-specific mechanisms in HFpEF and provides mechanistic insights into impaired excitation-contraction coupling and sex-dependent differential arrhythmia susceptibility in HFpEF with potential therapeutic implications. In male HFpEF myocytes, altered Ca2+ handling and electrophysiology aligned with diastolic dysfunction and arrhythmias, while worse diastolic dysfunction in females may depend more on altered myofilaments properties.

Aldosterone Effect on Cardiac Structure and Function

BACKGROUND

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

CONCLUSION

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

Inflammation as a therapeutic target in heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) accounts for around half of all cases of heart failure and may become the dominant type of heart failure in the near future. Unlike HF with reduced ejection fraction there are few evidence-based treatment strategies available. There is a significant unmet need for new strategies to improve clinical outcomes in HFpEF patients. Inflammation is widely thought to play a key role in HFpEF pathophysiology and may represent a viable treatment target. In this review focusing predominantly on clinical studies, we will summarise the role of inflammation in HFpEF and discuss potential therapeutic strategies targeting inflammation.

Aldosterone and cardiovascular diseases

Aldosterone's role in the kidney and its pathophysiologic actions in hypertension are well known. However, its role or that of its receptor [minieralocorticoid receptor (MR)] in other cardiovascular (CV) disease are less well described. To identify their potential roles in six CV conditions (heart failure, myocardial infarction, atrial fibrillation, stroke, atherosclerosis, and thrombosis), we assessed these associations in the following four areas: (i) mechanistic studies in rodents and humans; (ii) pre-clinical studies of MR antagonists; (iii) clinical trials of MR antagonists; and (iv) genetics. The data were acquired from an online search of the National Library of Medicine using the PubMed search engine from January 2011 through June 2021. There were 3702 publications identified with 200 publications meeting our inclusion and exclusion criteria. Data strongly supported an association between heart failure and dysregulated aldosterone/MR. This association is not surprising given aldosterone/MR's prominent role in regulating sodium/volume homeostasis. Atrial fibrillation and myocardial infarction are also associated with dysregulated aldosterone/MR, but less strongly. For the most part, the data were insufficient to determine whether there was a relationship between atherosclerosis, stroke, or thrombosis and aldosterone/MR dysregulation. This review clearly documented an expanding role for aldosterone/MR's dysregulation in CV diseases beyond hypertension. How expansive it might be is limited by the currently available data. It is anticipated that with an increased focus on aldosterone/MR's potential roles in these diseases, additional clinical and pre-clinical data will clarify these relationships, thereby, opening approaches to use modulators of aldosterone/MR's action to more precisely treat these CV conditions.

Cardiac Structure and Function Across the Spectrum of Aldosteronism: the Atherosclerosis Risk in Communities Study

BACKGROUND

Aldosterone production and mineralocorticoid receptor activation are implicated in myocardial fibrosis and cardiovascular events.

METHODS

Cardiac structure and function were assessed in 4547 participants without prevalent heart failure (HF) in the ARIC study (Atherosclerosis Risk in Communities), with echocardiography, aldosterone, and plasma renin activity measurement (2011-2013). Subjects were characterized by plasma renin activity as suppressed (≤0.5 ng/mL per hour) or unsuppressed (>0.5 ng/mL per hour). Cross-sectional relationships with cardiac structure and function, and longitudinal relationships with outcomes (HF hospitalization; HF and all-cause death; HF, death, myocardial infarction, and stroke; and incident atrial fibrillation) were assessed. Models were adjusted for demographic and anthropometric characteristics and additively, for blood pressure and antihypertensives.

RESULTS

Evidence of primary aldosteronism physiology was prevalent (11.6% with positive screen) and associated with echocardiographic parameters. Renin suppression was associated with greater left ventricular mass, left ventricular volumes, and left atrial volume index, and a lower E/A ratio (adjusted P<0.001 for all). Higher aldosterone was associated with greater left ventricular mass and lower global longitudinal strain and lateral E'. The highest tertile of aldosterone was associated with a hazard ratio of 1.37 (95% CI, 1.06-1.77; 5.5-year follow-up) for incident atrial fibrillation relative to the lowest. Renin suppression was associated with HF (hazard ratio, 1.34 [95% CI, 1.05-1.72]; 7.3-year follow-up), although these relationships did not remain statistically significant after additional adjustment for hypertension.

CONCLUSIONS

Renin suppression and aldosterone excess, consistent with primary aldosteronism pathophysiology, were associated with cardiac structural and functional alterations and may represent an early target for mitigation of fibrosis with mineralocorticoid receptor antagonists.

Aldosterone dysregulation predicts the risk of mortality and rehospitalization in heart failure with a preserved ejection fraction

Serum aldosterone is associated with cardiac remodeling, which contributes to morbidity and mortality in heart failure (HF); however, the prognostic value of aldosterone in HF with a preserved ejection fraction (HFpEF) is unclear. We used liquid chromatography-tandem mass spectrometry to quantify serum aldosterone in 873 patients with HFpEF in a Registry Study of Biomarkers for HF. The retrospective study was conducted at Beijing Anzhen Hospital from May 2017 to October 2019. The primary endpoint was a composite of all-cause mortality and rehospitalization for HF. Aldosterone concentrations in patients with and without events were 124.22 pmol L^-1 (interquartile range (IQR): 48.62-256.20) and 96.33 pmol L^-1 (IQR: 37.33-215.76), respectively (P=0.023). Aldosterone independently predicted all-cause mortality (adjusted hazard ratio (aHR), 1.55; 95% confidence interval (95%CI), 1.06-2.27; P=0.024) and the primary endpoint (aHR, 1.43; 95%CI, 1.11-1.85; P=0.006). Patients with high aldosterone concentrations were at higher risk of concentric remodeling (adjusted odds ratio (aOR), 1.45; 95% CI, 1.03-2.04; P=0.034). Patients with high aldosterone and B-type natriuretic peptide concentrations were at a higher risk of the primary endpoint (hazard ratio (HR), 1.85; 95%CI, 1.29-2.66; P=0.001). We conclude that elevated aldosterone is associated with a risk of rehospitalization with HF and all-cause mortality in patients with HFpEF.

[The importance of health-related quality of life at baseline in predicting event-free survival in patients with a cardiovascular risk profile]

The importance of health-related quality of life at baseline in predicting event-free survival in patients with a cardiovascular risk profile Background: Manifest heart failure impairs all dimensions of health-related quality of life (HRQOL). However, the role of HRQOL in patients with risk factors for the development of heart failure with preserved ejection fraction (HFpEF) is only poorly understood. Objective: In this post-hoc analysis of the DIAST-CHF observational study, we tested the hypothesis whether a lower HRQOL at baseline is prognostically associated with an increase in cardiovascular events during follow-up in elderly patients with a cardiovascular risk profile. Methods: The DIAST-CHF observational study enrolled 1.937 patients aged 50 to 85 years with at least one risk factor for the development of HFpEF. HRQOL was assessed using the German version of the Short-Form-36 (SF-36) Health Survey. Results: Patients with comorbid chronic diseases, including manifest heart failure, coronary artery disease, atrial fibrillation, diabetes mellitus and depression, rated their health status (Self-rated health, SRH) significantly worse than those without comorbidities. Older age, higher body-mass index and elevated serum amino-terminal pro-brain natriuretic peptide (NTproBNP) concentration as well as lower left ventricular ejection fraction (LVEF) and impaired 6-minute walk test showed significant relationships to SRH. Kaplan-Meier analyses and Cox regression models using quartiles of either SF-36 subscales "Physical Component Summary" (PCS) or SRH groups demonstrated significant differences in event-free survival (all-cause death or cardiovascular hospitalization), whereas no difference in event-free survival was observed among the quartiles of the SF-36 subscale "Mental Component Summary" (MCS). Conclusion: In patients with risk factors for the development of HFpEF, HRQOL questionnaires are suitable instruments for risk stratification if they capture physical impairments, rather than psychological limitations of quality of life.

NR3C2 genotype is associated with response to spironolactone in diastolic heart failure patients from the Aldo-DHF trial

STUDY OBJECTIVE

This study aimed to determine if variants in NR3C2, which codes the target protein of spironolactone, or CYP11B2, which is involved in aldosterone synthesis, were associated with spironolactone response, focused on the primary end point of diastolic function (E/e'), in Aldosterone Receptor Blockade in Diastolic Heart Failure (Aldo-DHF) participants.

DESIGN

Post-hoc genetic analysis.

DATA SOURCE

Data and samples were derived from the multi-center, randomized, double-blind, placebo-controlled Aldo-DHF trial.

PATIENTS

Aldo-DHF participants treated with spironolactone (n = 184) or placebo (n = 178) were included.

INTERVENTION

Participants were genotyped for NR3C2 rs5522, NR3C2 rs2070951 and CYP11B2 rs1799998 via pyrosequencing.

MEASUREMENTS

In the placebo and spironolactone arms, separate multivariable linear regression analyses were performed for change in E/e' with each single nucleotide polymorphism (SNP), adjusted for age, sex, and baseline E/e'. To discern potential mechanisms of a genotype effect, associated SNPs were further examined for their association with change in blood pressure, circulating procollagen type III N-terminal peptide (PIIINP), and left atrial area.

MAIN RESULTS

Carriers of the rs5522 G allele in the placebo arm had a greater increase in E/e' over the 12-month course of the trial compared to noncarriers (β = 1.10; 95% confidence interval [CI]: 0.05-2.16; p = 0.04). No corresponding E/e' worsening by rs5522 genotype was observed in the spironolactone arm. None of the other genotypes were associated with change in E/e'. Compared to noncarriers, rs5522 G carriers also had a greater increase in left atrial area with placebo (β = 0.83; 95% CI: 0.17-1.48; p = 0.01) and a greater reduction in diastolic blood pressure with spironolactone (β = -3.56; 95% CI: -6.73 to -0.39; p = 0.03). Serum PIIINP levels were similar across rs5522 genotypes.

CONCLUSIONS

Our results suggest that spironolactone attenuates progression of diastolic dysfunction associated with the NR3C2 rs5522 G allele. Validation of our findings is needed.

Prevalence of primary aldosteronism and association with cardiovascular complications in patients with resistant and refractory hypertension

OBJECTIVES

To assess the prevalence of primary aldosteronism and its association with cardiometabolic complications in patients with resistant and refractory hypertension.

METHODS

One hundred and ten consecutive patients with true resistant hypertension [insufficient blood pressure control despite appropriate lifestyle measures and treatment with at least three classes of antihypertensive medication, including a diuretic] and without previous cardiovascular events were screened for secondary hypertension. Refractory hypertension was diagnosed in case of uncontrolled blood pressure despite the use of at least five antihypertensive drugs.

RESULTS

Primary aldosteronism was diagnosed in 32 cases (29.1%). The multivariate analysis showed that primary aldosteronism is a strong factor positively associated with left ventricular hypertrophy [odds ratio (OR) = 12.98, 95% confidence interval (CI) 3.82-60.88; P < 0.001], microalbuminuria (OR = 3.67, 95% CI 1.44-9.78; P = 0.007), carotid intima-media thickness at least 0.9 mm (OR = 2.69, 95% CI 1.02-7.82; P = 0.037), aortic ectasia (OR = 4.08, 95% CI 1,18-15.04; P = 0.027) and atrial fibrillation (OR 8.80, 95% CI 1.53-73.98; P = 0.022). Moreover, primary aldosteronism was independently associated with the presence of at least one (OR = 8.60, 95% CI 1.73-69.88; P = 0.018) and at least two types of organ damage (OR = 3.08, 95% CI 1.19-8.24; P = 0.022). Thirteen patients (11.8%) were affected by refractory hypertension. This group was characterized by significantly higher values of carotid intima-media thickness, higher rate of aldosterone-producing adenoma and atrial fibrillation, compared with the other individuals with resistant hypertension.

CONCLUSION

The current study indicates that primary aldosteronism is a frequent cause of secondary hypertension and cardiovascular complications among patients with resistant and refractory hypertension, suggesting a crucial role of aldosterone in the pathogenesis of severe hypertensive phenotypes and cardiovascular disease.

Relationship between plasma aldosterone and left ventricular structure and function in patients with heart failure with preserved ejection fraction

Aim. To study the relationship between plasma aldosterone level and left ventricular (LV) structure and function in heart failure with preserved ejection fraction (HFpEF).

Material and methods. This prospective study included 158 patients (58 men and 100 women, mean age, 62,3±7,4 years) with compensated HFpEF. Patients had no history of primary aldosteronism and did not use the mineralocorticoid receptor antagonists during the last 6 weeks. The plasma aldosterone was determined by enzyme immunoassay in all patients and the severity of structural and functional cardiac changes was assessed. The concentration of 40160 pg/ml was considered the reference values. Assessment of cardiac structure and function was carried out using transthoracic echocardiography.

Results. According to the laboratory results, all patients were divided into two groups: group 1 — 99 (62,7%) patients (95% confidence interval (CI), 55,0-70,0%) with normal aldosterone levels; group 2 — 59 (37,3%) patients (95% Cl, 30,0-45,0%) with hyperaldosteronism. End-diastolic volume, left atrial volume, LV mass index, severity of LV diastolic dysfunction and the prevalence of concentric hypertrophy were significantly higher in group 2 patients compared with group 1 (p<0,05 for all). Blood aldosterone levels positively correlated with E/e’ (r=0,63, p<0,001). Regression analysis, adjusted for age and comorbidity, demonstrated that plasma aldosterone levels were closely associated with E/e’ (odds ratio, 3,42; 95% CI, 1,65-9,64, p=0,001) and LV concentric hypertrophy (odds ratio, 1,12; 95% CI, 1,08-3,16, p=0,042).

Conclusion. The development of secondary hyperaldosteronism in patients with HFpEF is an independent predictor of LV diastolic dysfunction and unfavorable prognostic types of LV remodeling.

The effect of spironolactone on diastolic function in haemodialysis patients

Heart failure with preserved ejection fraction (HFpEF) is highly prevalent in patients on maintenance haemodialysis (HD) and lacks effective treatment. We investigated the effect of spironolactone on cardiac structure and function with a specific focus on diastolic function parameters. The MiREnDa trial examined the effect of 50 mg spironolactone once daily versus placebo on left ventricular mass index (LVMi) among 97 HD patients during 40 weeks of treatment. In this echocardiographic substudy, diastolic function was assessed using predefined structural and functional parameters including E/e’. Changes in the frequency of HFpEF were analysed using the comprehensive ‘HFA-PEFF score’. Complete echocardiographic assessment was available in 65 individuals (59.5 ± 13.0 years, 21.5% female) with preserved left ventricular ejection fraction (LVEF > 50%). At baseline, mean E/e’ was 15.2 ± 7.8 and 37 (56.9%) patients fulfilled the criteria of HFpEF according to the HFA-PEFF score. There was no significant difference in mean change of E/e’ between the spironolactone group and the placebo group (+ 0.93 ± 5.39 vs. + 1.52 ± 5.94, p = 0.68) or in mean change of left atrial volume index (LAVi) (1.9 ± 12.3 ml/m² vs. 1.7 ± 14.1 ml/m², p = 0.89). Furthermore, spironolactone had no significant effect on mean change in LVMi (+ 0.8 ± 14.2 g/m² vs. + 2.7 ± 15.9 g/m²; p = 0.72) or NT-proBNP (p = 0.96). Treatment with spironolactone did not alter HFA-PEFF score class compared with placebo (p = 0.63). Treatment with 50 mg of spironolactone for 40 weeks had no significant effect on diastolic function parameters in HD patients.

The trial has been registered at clinicaltrials.gov (NCT01691053; first posted Sep. 24, 2012).

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

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

Characterization of the inflammatory-metabolic phenotype of heart failure with a preserved ejection fraction: a hypothesis to explain influence of sex on the evolution and potential treatment of the disease

Accumulating evidence points to the existence of an inflammatory-metabolic phenotype of heart failure with a preserved ejection fraction (HFpEF), which is characterized by biomarkers of inflammation, an expanded epicardial adipose tissue mass, microvascular endothelial dysfunction, normal-to-mildly increased left ventricular volumes and systolic blood pressures, and possibly, altered activity of adipocyte-associated inflammatory mediators. A broad range of adipogenic metabolic and systemic inflammatory disorders - e.g. obesity, diabetes and metabolic syndrome as well as rheumatoid arthritis and psoriasis - can cause this phenotype, independent of the presence of large vessel coronary artery disease. Interestingly, when compared with men, women are both at greater risk of and may suffer greater cardiac consequences from these systemic inflammatory and metabolic disorders. Women show disproportionate increases in left ventricular filling pressures following increases in central blood volume and have greater arterial stiffness than men. Additionally, they are particularly predisposed to epicardial and intramyocardial fat expansion and imbalances in adipocyte-associated proinflammatory mediators. The hormonal interrelationships seen in inflammatory-metabolic phenotype may explain why mineralocorticoid receptor antagonists and neprilysin inhibitors may be more effective in women than in men with HFpEF. Recognition of the inflammatory-metabolic phenotype may improve an understanding of the pathogenesis of HFpEF and enhance the ability to design clinical trials of interventions in this heterogeneous syndrome.

U-shaped relationship between left ventricular mass index and estimated glomerular filtration rate in patients with primary aldosteronism

Estimated glomerular filtration rate (eGFR) is an important topic in patients with primary aldosteronism (PA). However, the relationship between left ventricular structure and eGFR is unclear. We conducted a prospective, observational, and cross-sectional study to analyze 168 patients with PA and 168 propensity score-matched patients with essential hypertension (EH) as the control group, matched by age, gender, and systolic blood pressure. In the patients with PA, the eGFR was not correlated with left ventricular mass index (LVMI; r=-0.065, p=0.404), while in the patients with EH, the eGFR was negatively correlated with LVMI (r=-0.309, p<0.001). To test whether eGFR had a non-linear relationship with LVMI among the patients with PA, we stratified the patients with PA according to the tertile of eGFR (low, medium, and high tertile). The medium tertile of patients had a significantly lower LVMI than those in the other two tertiles (LVMI: 143.5±41.6, 120.5±40.5, and 133.1±34.3 g/m², from the lowest to highest tertile of eGFR; analysis of covariance p=0.032). The medium tertile of eGFR is associated with lowest LVMI. Patients with PA with high and low eGFR were associated with higher LVMI. The findings implied that the reasons for an increased LVMI in patients with PA may be different to those in patients with EH.

Biomarkers of Inflammation in Left Ventricular Diastolic Dysfunction

Left ventricular diastolic dysfunction (LVDD) is an important precursor to many different cardiovascular diseases. Diastolic abnormalities have been studied extensively in the past decade, and it has been confirmed that one of the mechanisms leading to heart failure is a chronic, low-grade inflammatory reaction. The triggers are classical cardiovascular risk factors, grouped under the name of metabolic syndrome (MetS), or other systemic diseases that have an inflammatory substrate such as chronic obstructive pulmonary disease. The triggers could induce myocardial apoptosis and reduce ventricular wall compliance through the release of cytokines by multiple pathways such as (1) immune reaction, (2) prolonged cell hypoxemia, or (3) excessive activation of neuroendocrine and autonomic nerve function disorder. The systemic proinflammatory state causes coronary microvascular endothelial inflammation which reduces nitric oxide bioavailability, cyclic guanosine monophosphate content, and protein kinase G (PKG) activity in adjacent cardiomyocytes favoring hypertrophy development and increases resting tension. So far, it has been found that inflammatory cytokines associated with the heart failure mechanism include TNF-α, IL-6, IL-8, IL-10, IL-1α, IL-1β, IL-2, TGF-β, and IFN-γ. Some of them could be used as diagnosis biomarkers. The present review aims at discussing the inflammatory mechanisms behind diastolic dysfunction and their triggering conditions, cytokines, and possible future inflammatory biomarkers useful for diagnosis.

Plasma xanthine oxidase activity is related to increased sodium and left ventricular hypertrophy in resistant hypertension

BACKGROUND

The extra-renal effects of aldosterone on left ventricular (LV) structure and function are exacerbated by increased dietary sodium in persons with hypertension. Previous studies demonstrated endothelial dysfunction and increased oxidative stress with high salt diet in normotensive salt-resistant subjects. We hypothesized that increased xanthine oxidase (XO), a product of endothelial cells, is related to 24-h urinary sodium and to LV hypertrophy and function in patients with resistant hypertension (RHTN).

METHODS

The study group included persons with RHTN (n = 91), defined as a blood pressure > 140/90 mmHg on ≥ 3 medications at pharmacologically effective doses. Plasma XO activity and 24-h urine were collected, and cardiac magnetic resonance imaging (MRI) was performed to assess LV function and morphology. Sixty-seven normotensive persons on no cardiovascular medications served as controls. A subset of RHTN (n = 19) received spironolactone without salt restriction for six months with follow-up XO activity measurements and MRI analyses.

RESULTS

XO activity was increased two-fold in RHTN vs. normal and was positively correlated with LV mass, LV diastolic function, and 24-h urinary sodium. In RHTN patients receiving spironolactone without salt restriction, LV mass decreased, but LV diastolic function and XO activity did not improve. Baseline urinary sodium was positively associated with rate of change of LV mass to volume ratio and the LV E/A ratio.

CONCLUSIONS

These results demonstrate a potential role of endothelium-derived oxidative stress and excess dietary salt in the pathophysiology of LV hypertrophy and diastolic dysfunction in persons with RHTN unaffected by the addition of spironolactone.

Sex Differences in Outcomes and Responses to Spironolactone in Heart Failure With Preserved Ejection Fraction: A Secondary Analysis of TOPCAT Trial

OBJECTIVES

This study sought to investigate sex differences in outcomes and responses to spironolactone in patients with heart failure with preserved ejection fraction (HFpEF).

BACKGROUND

HFpEF affects women more frequently than men. Sex differences in responses to effects of mineralocorticoid antagonists have not been reported.

METHODS

This was an exploratory, post hoc, non-pre-specified analysis of the TOPCAT (Aldosterone Antagonist Therapy for Adults With Heart Failure and Preserved Systolic Function) trial. Subjects with symptomatic HF and a left ventricular ejection fraction ≥45% were randomized to spironolactone or placebo therapy. Subjects enrolled from the Americas were analyzed. The primary outcome was a composite of cardiovascular (CV) death, cardiac arrest, or HF hospitalization. Secondary outcomes included all-cause mortality, CV, and non-CV mortality and CV, HF, and non-CV hospitalization. Sex differences in outcomes and treatment effects were determined using time-to-event analysis.

RESULTS

In total, 882 of 1,767 subjects (49.9%) were women. Women were older with fewer comorbidities but worse patient-reported outcomes. There were no sex differences in outcomes in the placebo arm or in response to spironolactone for the primary outcome or its components. Spironolactone therapy was associated with reduced all-cause mortality in women (hazard ratio: 0.66; p = 0.01) but not in men (pinteraction = 0.02).

CONCLUSIONS

In TOPCAT, women and men presented with different clinical profiles and similar clinical outcomes. The interaction between spironolactone and sex in TOPCAT overall and in the present analysis was nonsignificant for the primary outcome, but there was a reduction in all-cause mortality associated with spironolactone therapy in women, with a significant interaction between sex and treatment arm. Prospective evaluation is needed to determine whether spironolactone therapy may be effective for treatment of HFpEF in women. (Aldosterone Antagonist Therapy for Adults With Heart Failure and Preserved Systolic Function [TOPCAT]; NCT00094302).

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.

Effect of Aldosterone Antagonism on Exercise Tolerance in Heart Failure With Preserved Ejection Fraction

BACKGROUND

Impaired functional capacity is a hallmark of patients with heart failure with preserved ejection fraction (HFpEF). Despite the association of HFpEF with reduced myocardial compliance attributed to fibrosis, spironolactone has not been shown to alter outcomes-perhaps reflecting the heterogeneity of underlying pathological mechanisms.

OBJECTIVES

The authors sought to identify improvement in exercise capacity with spironolactone in the subset of patients with HFpEF with exercise-induced increase in ratio between early mitral inflow velocity and mitral annular early diastolic velocity (E/e') reflecting elevation of left ventricular (LV) filling pressure.

METHODS

In this randomized, blinded, parallel-group, placebo-controlled trial, 150 subjects (age 67 ± 9 years) with exertional dyspnea (New York Heart Association functional class II to III, left ventricular ejection fraction >50%, diastolic dysfunction, and exertional E/e' >13), excluding those with ischemic heart disease, were recruited in a tertiary cardiology center. Patients were randomized to 6 months of oral spironolactone 25 mg/day or matching placebo. Primary outcomes were improvements in peak oxygen uptake (VO₂) and exertional E/e' ratio, and secondary outcomes were improvements in exercise blood pressure response and global LV longitudinal strain.

RESULTS

At follow-up, 131 patients completed therapy-64 taking spironolactone and 67 placebo. At baseline, subjects had substantial exercise limitation (peak VO₂ 64 ± 17% predicted). The spironolactone group showed improvement in exercise capacity (increment in peak VO₂ [2.9 ml/min/kg (95% confidence interval [CI]: 1.9 to 3.9 ml/min/kg) vs. 0.3 ml/min/kg (95% CI: -0.5 to 1.1 ml/min/kg); p < 0.001], anaerobic threshold [2.0 ml/min/kg (95% CI: 0.9 to 3.2 ml/min/kg) vs. -0.9 ml/min/kg (95% CI: -3.4 to 1.6 ml/min/kg); p = 0.03], and O₂ uptake efficiency [0.19 (95% CI: 0.06 to 0.31) vs. -0.07 (95% CI: -0.17 to 0.04); p = 0.002]), with reduction in exercise-induced increase in E/e' (-3.0 [95% CI: -3.9 to -2.0] vs. 0.5 [95% CI: -0.6 to 1.6]; p < 0.001). There was a significant interaction of spironolactone and change in E/e' on VO₂ (p = 0.039).

CONCLUSIONS

In patients with HFpEF and abnormal diastolic response to exertion, improvement in exercise E/e' mediates the beneficial effect of spironolactone on exercise capacity. Identification of exercise-induced increase in LV filling pressure in patients with HFpEF may define a subgroup with warranting trial of spironolactone.

Targets for Heart Failure With Preserved Ejection Fraction

Heart failure (HF) with preserved ejection fraction (HFPEF) is responsible for half of all HF cases and will be the most common form of HF within the next 5 years. Previous studies of pharmacological agents in HFPEF have proved neutral or negative, in part due to phenotypic heterogeneity and complex underlying mechanisms. This review summarizes the key molecular and cellular pathways characterized in HFPEF as well as current and future therapies that target these mechanisms.

Association of Post-Saline Load Plasma Aldosterone Levels With Left Ventricular Hypertrophy in Primary Hypertension

BACKGROUND

Left ventricular hypertrophy (LVH) is an independent risk factor for cardiovascular morbidity in hypertension. Current evidence suggests a contribution to LVH of plasma aldosterone levels that are inappropriately elevated for the salt status. The aim of this study was to investigate whether inappropriate modulation of aldosterone production by a saline load is associated with left ventricular (LV) mass in hypertensive patients.

METHODS

In 90 hypertensive patients free of clinically relevant cardiovascular complications in whom secondary forms of hypertension were ruled out, we performed a standard intravenous saline load (0.9% NaCl, 2 l in 4 hours) with measurement of plasma aldosterone and active renin at baseline and end of infusion. Bi-dimensional echocardiography was performed for the assessment of cardiac morphology and function.

RESULTS

LVH was present in 19% of patients who had significantly worse renal function and higher body mass, blood pressure, and plasma aldosterone levels measured both at baseline and after the saline load than patients without LVH. LV mass was directly related to age, body mass, systolic blood pressure, duration of hypertension, baseline, and post-saline load plasma aldosterone levels and inversely to glomerular filtration. Multivariate regression analysis showed independent correlation of LV mass with body mass, systolic blood pressure, and plasma aldosterone levels measured after intravenous saline load, but not at baseline.

CONCLUSIONS

In patients with hypertension, aldosterone levels measured after intravenous saline load are related to LV mass independent of age, body mass, and blood pressure, suggesting that limited ability of salt to modulate aldosterone production could contribute to LVH.

Aldosterone and Left Ventricular Remodeling

Experimental and clinical evidence obtained in the last 2 decades clearly indicates that protracted exposure to inappropriately elevated aldosterone levels causes significant changes in left ventricular structure and function. Animal studies have demonstrated that aldosterone induces myocardial inflammatory changes and fibrosis in the presence of a high salt diet. Moreover, the effects of aldosterone on the heart have been investigated in different clinical conditions. These conditions include systolic and diastolic heart failure, essential hypertension, and primary aldosteronism that offers a unique clinical model to study the cardiac effects of excess aldosterone because these effects are isolated from those of the renin-angiotensin axis. A relatively clear picture is emerging from these studies with regard to aldosterone-related changes in left ventricular mass and geometry. Conversely, no direct effect of aldosterone on left ventricular diastolic function can be demonstrated and improvement of diastolic function obtained in some studies that have employed mineralocorticoid receptor blockers could result from left ventricular mass reduction. Animal experiments demonstrate that effects of aldosterone on the left ventricle require high salt intake to occur, but the evidence of this contribution of salt to aldosterone-induced cardiac changes in humans remains weaker and needs further research. The article reviews the results of clinical studies addressing the role of aldosterone in regulation of LV remodeling and diastolic function, and focuses on the possible relevance of salt intake.

Effect of Mineralocorticoid Receptor Antagonists on Cardiac Structure and Function in Patients With Diastolic Dysfunction and Heart Failure With Preserved Ejection Fraction: A Meta-Analysis and Systematic Review

BACKGROUND

There has been an increasing interest in use of mineralocorticoid receptor antagonists (MRAs) in patients with heart failure with preserved ejection fraction (HFPEF). However, a comprehensive evaluation of MRA effects on left ventricular (LV) structure and function in these patients is lacking. In this meta-analysis, we evaluated the effects of MRAs on LV structure and function among patients with diastolic dysfunction or HFPEF.

METHODS & RESULTS

Randomized, controlled clinical trials evaluating the efficacy of MRAs in patients with diastolic dysfunction or HFPEF were included. The primary outcome was change in E/e', a specific measure of diastolic function. Secondary outcomes included changes in other measures of diastolic function, LV structure, surrogate markers for myocardial fibrosis (carboxy-terminal peptide of procollagen type I [PICP] and amino-terminal peptide of pro-collagen type-II [PIIINP]), blood pressure, and exercise tolerance. In the pooled analysis, MRA use was associated with significant reduction in E/e' (weighted mean difference [WMD] [95% confidence interval {CI}]: -1.68 [-2.03 to -1.33]; P<0.0001) and deceleration time (WMD [95% CI]: -12.0 ms [-23.3 to -0.7]; P=0.04) as compared with control, suggesting and improvement in diastolic function. Furthermore, blood pressure and levels of PIIINP and PICP were also significantly reduced with MRA therapy with no significant change in LV mass or dimensions.

CONCLUSION

MRA therapy in patients with asymptomatic diastolic dysfunction or HFPEF is associated with significant improvement in diastolic function and markers of cardiac fibrosis without a significant change in LV mass or dimensions.

Elevated Plasma C-Terminal Endothelin-1 Precursor Fragment Concentrations Are Associated with Less Anxiety in Patients with Cardiovascular Risk Factors. Results from the Observational DIAST-CHF Study

Background

The role of endothelin-1 (ET-1) in the neurobiology of anxiety is unknown, therefore, we assessed in the observational multicenter DIAST-CHF study whether the C-terminal ET-1 precursor fragment (CT-proET-1) is linked to anxiety.

Methods

Plasma concentrations of CT-proET-1 were measured in a total of 1,410 patients presenting with cardiovascular risk factors (mean age 66.91±8.2 years, 49.3% males, mean left ventricular ejection fraction 60.0±8.2%) who had completed the Hospital Anxiety and Depression Scale (HADS) questionnaire.

Results

Among the total study cohort (n = 1,410), there were 118 subjects (8.4%) with an HADS anxiety score above the cut-off level of 11 suggestive of clinically relevant anxiety. Plasma CT-proET-1 levels were significantly lower in the group of anxious patients as compared to non-anxious patients (p = 0.013). In regression models adjusted for sex, age, systolic blood pressure, and diameters of left atrium and ventricle, plasma CT-proET-1 was again linked to anxiety (Exp(β) = 0.247, 95%-confidence interval [95%-CI] = 0.067–0.914, p = 0.036). Given the high prevalence of depressive disorders in anxious patients, we additionally included the HADS depression score as an independent variable in the models and found that CT-proET-1 remained a significant predictor of anxiety, independent of comorbid depression (Exp(β) = 0.114, 95%-CI = 0.023–0.566, p = 0.008).

Conclusions

Our data from a population-based study in outpatients with cardiovascular risk factors revealed that circulating CT-proET-1 levels are negatively associated with anxiety. Further investigations are required to clarify the putative anxiolytic effect of ET-1 or its precursor molecules in humans and to decipher its mechanistic pathways.

Effects of renin-angiotensin-aldosterone system inhibitors on mortality, hospitalization, and diastolic function in patients with HFpEF. A meta-analysis of 13 randomized controlled trials

AIM

The purpose of this meta-analysis was to evaluate the effects of renin-angiotensin-aldosterone system (RAAS) inhibitors on mortality, hospitalization, diastolic function, and exercise capacity in heart failure with preserved ejection fraction (HFpEF).

METHODS

Thirteen randomized controlled trials (RCTs), totaling 12,532 patients with HFpEF, were selected. All-cause and cardiovascular mortality, all-cause and heart failure-related hospitalization, diastolic function, and the 6-min walk distance were assessed. The risk ratios (RR) of the dichotomous data, weighted mean difference (WMD) of continuous data, and 95 % confidence intervals (CI) were calculated to assess the effects of RAAS inhibitors.

RESULTS

RAAS inhibitors significantly decreased heart failure-related hospitalization (RR 0.89; 95 % CI 0.82-0.97; p = 0.01) and improved the diastolic function, as reflected in a reduced E/e' index (MD -1.38; 95 % CI -2.01 to -0.74; p < 0.0001). However, there were no beneficial effects on all-cause cardiovascular mortality and all-cause hospitalization. Other diastolic parameters had few changes compared with the controls. The 6-min walk distance was not improved by the use of RAAS inhibitors.

CONCLUSION

In patients with HFpEF, RAAS inhibitors decreased heart-failure hospitalization and the E/e' index without affecting mortality, all-cause hospitalization, other diastolic function parameters, and the 6-min walk distance.

Interrelated aldosterone and parathyroid hormone mutually modify cardiovascular mortality risk

BACKGROUND

Inappropriate aldosterone and parathyroid hormone (PTH) secretion is associated with increased cardiovascular risk. Accumulating evidence suggests bidirectional interplay between aldosterone and PTH.

METHODS

We evaluated the cross-sectional relationship between plasma aldosterone concentration (PAC), aldosterone to renin ratio (ARR) and PTH and subsequently tested whether the interaction between PAC and PTH modified the risk of cardiovascular death. PAC [78.0 (48.0-123.0) pg/mL], ARR [6.4 (2.9-12.9) pg/mL/pg/mL] and PTH concentration [median: 29.0 (22.0-40.0) pg/mL] were measured in 3074 patients (mean age: 62.5 ± 10.6 years; 30.3% women) referred to coronary angiography in a tertiary care center in Southwest Germany.

RESULTS

Using multiple linear regression analysis, PAC and ARR emerged as an independent predictor of higher PTH concentrations (β=0.12 and 0.21, P<0.001 for both) irrespective of intake of antihypertensive treatment, 25(OH)D, kidney function, serum calcium, phosphate, magnesium, cortisol, NT-pro-BNP, soluble α-klotho and FGF-23 concentration. After a median follow-up of 9.9 years, 512 (16.7%) participants had died due to fatal cardiovascular events. Multivariate Cox proportional hazard analysis revealed that both PAC and PTH were independently associated with cardiovascular mortality, with a potential synergistic interaction (P=0.028). PAC and PTH are exclusively associated with cardiovascular death in subjects with PTH and PAC concentrations above the median, respectively (PAC: HR per log SD: 1.14; 95% CI 1.02-1.29; P=0.026; PTH: HR per log SD: 1.18; 95% CI 1.02-1.37; P=0.031).

CONCLUSIONS

Higher PAC and ARR were independently associated with PTH. PAC was independently related to incident cardiovascular mortality exclusively in patients with elevated PTH and vice versa.

Effects of mineralocorticoid receptor antagonists in patients with preserved ejection fraction: a meta-analysis of randomized clinical trials

BACKGROUND

Mineralocorticoid receptor antagonists (MRAs) have been shown to be effective in patients with heart failure or myocardial infarction complicated by a reduced ejection fraction. However, the role of MRAs in patients with preserved ejection fraction (PEF) remains to be clarified. We aimed to summarize the evidence for the efficacy of MRAs in patients with either heart failure with PEF (HF-PEF) or myocardial infarction with PEF (MI-PEF).

METHODS

We searched PubMed, EMBASE, Cochrane Library, and clinical trials databases for randomized controlled trials, through June 2014, assessing MRA treatment in HF-PEF or MI-PEF patients. Fourteen randomized controlled trials (MI-PEF, 5; HF-PEF, 9; n = 6,428 patients) were included.

RESULTS

MRA treatment reduced the risk of hospitalization for heart failure (relative risk, 0.83; 95% confidence interval [CI], 0.70 to 0.98), improved quality of life (weighted mean difference [WMD], -5.16; 95% CI, -8.03 to -2.30), left ventricular end-diastolic diameter (standardized mean difference, -0.21; 95% CI, 0.32 to -0.11), and serum amino-terminal peptide of procollagen type-III level (WMD, -1.50, 95% CI, -1.72 to -1.29) in patients with PEF. In addition, MRAs reduced E/e'(an echocardiographic estimate of filling pressure for assessment of diastolic function; WMD, -1.82; 95% CI, -2.23 to -1.42) in HF-PEF patients and E/A ratio (the ratio of early to late diastolic transmitral flow; WMD, 0.12; 95% CI, 0.10 to 0.14) in MI-PEF patients. However, all-cause mortality was not improved by MRAs in either HF-PEF (P = 0.90) or MI-PEF (P = 0.27) patients.

CONCLUSIONS

MRA treatment in PEF patients led to reduced hospitalization for heart failure, quantifiable improvements in quality of life and diastolic function, and reversal of cardiac remodeling, but did not provide any all-cause mortality benefit.

Plasma aldosterone and its relationship with left ventricular mass in hypertensive patients with early-stage chronic kidney disease

Plasma aldosterone concentrations (PACs) are often increased in the advanced stages of chronic kidney disease (CKD); however, PAC has not been fully investigated in early CKD. Moreover, little is known about the relationship between aldosteronemia and left ventricular (LV) mass in subjects with mild-to-moderate CKD. The study objectives were to analyze PAC, LV mass (LVM), LV geometry and their relationships, in a group of hypertensive patients with stage I-III CKD. One hundred ninety-five hypertensive patients with stage I-III CKD were enrolled and compared with a control group of 82 hypertensive patients without renal dysfunction. LVM was higher in subjects with CKD than in the control group and increased progressively with advancing stages of CKD (P=0.004). A similar trend was observed for PAC (P<0.0001), in which PAC was greater in CKD subjects with LV concentric geometry than in those with eccentric LV hypertrophy (P=0.01). Furthermore, in CKD patients, PAC was directly and significantly correlated with LVM (r=0.29; P<0.0001) and with relative wall thickness (RWT; r=0.36; P<0.0001). These associations remained significant even after adjustment for various confounding factors in multiple regression analyses (P<0.001). In summary, the results demonstrated that in CKD hypertensive patients, LVM, RWT and PAC are increased and related to each other from the earliest stages of renal dysfunction. Furthermore, it seems biologically plausible to speculate that aldosterone may promote a concentric geometry of the left ventricle and increase LVM in hypertensive patients with early CKD.

Cardiac effects of aldosterone: does gender matter?

Ischemic heart disease (IHD) continues to be the most common cause of death globally, although mortality rates are decreasing with significant advances in treatment. Higher prevalence of co-morbidities in women only partly explains the lack of decrease in mortality rates in younger women due to. Until recently there has been gender bias in pre-clinical studies and many clinical trials, resulting in a significant gap in knowledge whether there are differential responses to therapy for women, particularly younger women. There is increasing evidence that there are significant gender-specific differences in the outcome of post-infarction remodelling, prevalence of hypertension and sudden cardiac death. These differences indicate that cardiac tissue in females displays significant physiological and biochemical differences compared to males. However, the mechanisms mediating these differences, and how they change with age, are poorly understood. Circulating levels and physiological effects of aldosterone vary across the menstrual cycle suggesting female steroid sex hormones may not only regulate production of, but also responses to, aldosterone in pre-menopausal women. This modified tissue response may foster a homeostatic environment where higher levels of aldosterone are tolerated without adverse cardiac effect. Moreover, there is limited data on the direct regulation of this signalling axis by androgens in female animals/subjects. This review explores the relationship between gender and the effects of aldosterone in cardiovascular disease (CVD), an issue of significant need that may lead to changes in best practice to optimise clinical care and improve outcomes for females with CVD.

Safety evaluation and risk assessment of electronic cigarettes as tobacco cigarette substitutes: a systematic review

Electronic cigarettes are a recent development in tobacco harm reduction. They are marketed as less harmful alternatives to smoking. Awareness and use of these devices has grown exponentially in recent years, with millions of people currently using them. This systematic review appraises existing laboratory and clinical research on the potential risks from electronic cigarette use, compared with the well-established devastating effects of smoking tobacco cigarettes. Currently available evidence indicates that electronic cigarettes are by far a less harmful alternative to smoking and significant health benefits are expected in smokers who switch from tobacco to electronic cigarettes. Research will help make electronic cigarettes more effective as smoking substitutes and will better define and further reduce residual risks from use to as low as possible, by establishing appropriate quality control and standards.

Electronic nicotine delivery systems ("e-cigarettes"): review of safety and smoking cessation efficacy

BACKGROUND AND OBJECTIVES

Cigarette smoking is common among cancer patients and is associated with negative outcomes. Electronic nicotine delivery systems ("e-cigarettes") are rapidly growing in popularity and use, but there is limited information on their safety or effectiveness in helping individuals quit smoking.

DATA SOURCES

The authors searched PubMed, Web of Science, and additional sources for published empirical data on safety and use of electronic cigarettes as an aid to quit smoking.

REVIEW METHODS

We conducted a structured search of the current literature up to and including November 2013.

RESULTS

E-cigarettes currently vary widely in their contents and are sometimes inconsistent with labeling. Compared to tobacco cigarettes, available evidence suggests that e-cigarettes are often substantially lower in toxic content, cytotoxicity, associated adverse effects, and secondhand toxicity exposure. Data on the use of e-cigarettes for quitting smoking are suggestive but ultimately inconclusive.

CONCLUSIONS

Clinicians are advised to be aware that the use of e-cigarettes, especially among cigarette smokers, is growing rapidly. These devices are unregulated, of unknown safety, and of uncertain benefit in quitting smoking.

IMPLICATIONS FOR PRACTICE

In the absence of further data or regulation, oncologists are advised to discuss the known and unknown safety and efficacy information on e-cigarettes with interested patients and to encourage patients to first try FDA-approved pharmacotherapies for smoking cessation.

Marinobufagenin in essential hypertension and primary aldosteronism: a cardiotonic steroid with clinical and diagnostic implications

BACKGROUND

The cardiotonic steroid marinobufagenin (MBG) is increasingly suggested to be responsible for some of the cardiovascular injury that has been previously attributed to aldosterone. We examined the clinical correlates of circulating MBG concentrations in hypertensive patients and tested the hypothesis that MBG serves as a reliable diagnostic tool for detecting primary aldosteronism (PA).

METHODS

Plasma MBG concentrations (mean: 0.51±0.25 nmol/l) were measured in the morning fasting samples in 20 patients with PA and 20 essential hypertensive (EH) controls matched for age, sex, body mass index, renal function, urinary sodium and intake of antihypertensive medication (mean age: 51.6 years; 52.2% women).

RESULTS

Overall, plasma MBG was directly correlated with plasma aldosterone, aldosterone to active renin ratio (AARR), diastolic blood pressure, mean carotid intima-media thickness, serum sodium, urinary protein to creatinine ratio and inversely with serum potassium levels. Plasma MBG levels were significantly higher in patients with PA compared to EH (mean: 0.68±0.12 versus 0.35±0.24 nmol/l; p<0.001). ROC analysis yielded a greater AUC for plasma MBG compared to the AARR, PAC and serum potassium levels for detecting PA. Youden's Index analyses yielded the optimal plasma MBG cut-off score for diagnosing PA at >0.49 nmol/l with specificity and sensitivity values of 0.85 and 0.95, respectively, which were higher than those at the optimum AARR cut-off at >3.32 ng/dl/µU/ml.

CONCLUSIONS

In a well-characterized cohort, values of plasma MBG were significantly related to clinical correlates of cardiovascular and renal disease. Plasma MBG emerged as a valuable alternative to the AARR for screening of PA.

The autocrine/paracrine loop after myocardial stretch: mineralocorticoid receptor activation

The stretch of cardiac muscle increases developed force in two phases. The first phase, which occurs rapidly, constitutes the well-known Frank-Starling mechanism and it is generally attributed to enhanced myofilament responsiveness to Ca(2+). The second phase or slow force response (SFR) occurs gradually and is due to an increase in the calcium transient amplitude as a result of a stretch-triggered autocrine/paracrine mechanism. We previously showed that Ca(2+) entry through reverse Na(+)/Ca(2+) exchange underlies the SFR, as the final step of an autocrine/paracrine cascade involving release of angiotensin II/endothelin, and a Na(+)/H(+) exchanger (NHE-1) activation-mediated rise in Na+. In the present review we mainly focus on our three latest contributions to the understanding of this signalling pathway triggered by myocardial stretch: 1) The finding that an increased production of reactive oxygen species (ROS) from mitochondrial origin is critical in the activation of the NHE-1 and therefore in the genesis of the SFR; 2) the demonstration of a key role played by the transactivation of the epidermal growth factor receptor; and 3) the involvement of mineralocorticoid receptors (MR) activation in the stretch-triggered cascade leading to the SFR. Among these novel contributions, the critical role played by the MR is perhaps the most important one. This finding may conceivably provide a mechanistic explanation to the recently discovered strikingly beneficial effects of MR antagonism in humans with cardiac hypertrophy and failure.

Aldosterone to active renin ratio is associated with nocturnal blood pressure in obese and treated hypertensive patients: the Styrian Hypertension Study

High aldosterone levels are considered to play a key role in arterial hypertension. Data on the relationship between the aldosterone to active renin ratio (AARR), a quantity of aldosterone excess, and ambulatory blood pressure (BP) monitoring (ABPM) during the night are, however, sparse. Hypertensive patients were recruited from local outpatient clinics who underwent 24-hour urine collection and in parallel ABPM. Plasma aldosterone and renin concentrations were measured by radioimmunoassay. A total of 211 patients (age, 60.2±10.2 years; 51.9% female) with a mean systolic/diastolic ABPM value of 128.7±12.8/77.1±9.2 mm Hg were evaluated. In backwards linear regression analyses adjusted for age, sex, body mass index, smoking, glomerular filtration rate, hemoglobin A1c , N-terminal prohormone of brain natriuretic peptide, urinary sodium/potassium ratio, and ongoing antihypertensive medication, AARR was significantly associated with nocturnal systolic (ß-coefficient: 0.177; P=.017) and diastolic BP (ß-coefficient: 0.162; P=.027). In patients with arterial hypertension, a significant association between AARR and nighttime BP even after adjustment for a broad panel of confounders was found.

Relationship between Plasma Aldosterone Levels and Left Ventricular Mass in Hypertensive Africans

Background. Hypertension is the most common cardiovascular disease worldwide and is a major cause of morbidity and mortality. Studies have suggested that the activity of the renin-angiotensin-aldosterone system play a major role in the target organ damage such as left ventricular hypertrophy occuring in hypertension. We sought to determine the relationship between plasma aldosterone and left ventricular mass in untreated African hypertensives. Methods. We recruited 82 newly diagnosed and untreated hypertensives and 51 normal controls. Measurements obtained included echocardiographic LV mass index, plasma aldosterone and renin. Results. The hypertensive subjects had lower renin levels (21.03[6.974] versus 26.66[7.592] ng.mL⁻¹, P = 0.0013), higher LV mass index (52.56[14.483] versus 42.02[8.315] g.m^−2.7P < 0.0001) when compared with the controls. There were no univariate associations between LV mass index and plasma aldosterone (r = 0.0179, P = 0.57) and between LV mass index and plasma renin (r = 0.0887, P = 0.61). In a multivariate model involving LV mass index and age, sex, body mass index (BMI), plasma aldosterone, plasma renin and systolic blood pressure (SBP), only age (P = 0.008), BMI (P = 0.046), and SBP (P = 0.001) were independently associated with the LV mass index. Conclusions. In this group of hypertensive Africans, there is no independent association of plasma aldosterone with LV mass. The height of the blood pressure, the body mass index and the age of the subjects determined the LV mass.

Impact of aldosterone antagonists on the substrate for atrial fibrillation: aldosterone promotes oxidative stress and atrial structural/electrical remodeling

Atrial fibrillation (AF), the most common cardiac arrhythmia, is an electrocardiographic description of a condition with multiple and complex underlying mechanisms. Oxidative stress is an important driver of structural remodeling that creates a substrate for AF. Oxidant radicals may promote increase of atrial oxidative damage, electrical and structural remodeling, and atrial inflammation. AF and other cardiovascular morbidities activate angiotensin (Ang-II)-dependent and independent cascades. A key component of the renin-angiotensin-aldosterone system (RAAS) is the mineralocorticoid aldosterone. Recent studies provide evidence of myocardial aldosterone synthesis. Aldosterone promotes cardiac oxidative stress, inflammation and structural/electrical remodeling via multiple mechanisms. In HF patients, aldosterone production is enhanced. In patients and in experimental HF and AF models, aldosterone receptor antagonists have favorable influences on cardiac remodeling and oxidative stress. Therapeutic approaches that seek to reduce AF burden by modulating the aldosterone system are likely beneficial but underutilized.

Genetic predisposition to left ventricular hypertrophy and the potential involvement of cystatin-C in untreated hypertension

BACKGROUND

The angiotensinogen M235T and aldosterone synthase C-344T gene polymorphisms have been associated with cardiac and structure function. However, these associations in untreated hypertension remain unknown. We examined whether these variants determined both echocardiography indices and the potential associated underlying mechanisms, including cystatin-C and vascular inflammation.

METHODS

The study population consisted of 319 untreated patients and 191 healthy individuals. Polymorphisms were determined by polymerase chain reaction technique. Left cardiac indices of geometry and function were assessed by echocardiography. Cystatin-C, intracellular cell adhesion molecule 1, and vascular cell adhesion molecule 1 levels were measured by enzyme-linked immunosorbent assay, whereas high sensitivity C-reactive protein levels were measured by immunonephelometry.

RESULTS

There was no significant interaction between the angiotensinogen genotypes on left ventricular mass index (LVMI) and diastolic function indices in all study groups. Regarding C-344T polymorphism, TT homozygous hypertensive subjects exhibited higher values of LVMI compared with C allele carriers (P = 0.02) and higher prevalence of concentric hypertrophy (P < 0.001). However, this polymorphism was not associated with variations in left atrial volume and diastolic dysfunction. Cystatin-C levels were correlated with LVMI values (r = 0.22; P = 0.002) and mean E/A ratio (r = -0.24; P < 0.001). Interestingly, a linear increase of LVMI with cyctatin-C quartiles has been revealed (F = 5.01; P < 0.001). Moreover, post hoc tests showed that increased levels of cystatin-C (above 75th percentile) were significantly different between both the first (P = 0.009) and the second quartile (P = 0.02).

CONCLUSIONS

We have shown that C-344T potentially predicts higher values of LVMI and concentric hypertrophy in untreated hypertension, independently of renal function and subclinical inflammation. Increased levels of cystatin-C were correlated with higher LVMI values.