Aldosterone, mineralocorticoid receptor activation, and cardiovascular remodeling

Retrospective study on the short-term efficacy of different doses of Spironolactone in patients with heart failure of ischemic cardiomyopath and the influence of ventricular remodeling markers

OBJECTIVE

To evaluate the impact of varying dosages of Spironolactone on the short-term effectiveness and ventricular remodeling indicators in patients with Heart Failure of Ischemic Cardiomyopathy (HFIC).

METHODS

A cohort of 141 HFIC patients, admitted to our hospital between October 2018 and February 2023, were enrolled for this study. Alongside the standard treatment for Chronic Congestive Heart Failure (CHF), these patients were randomly assigned to either a low-dose (20 mg/d, N=70) or a high-dose (60 mg/d, N=71) Spironolactone group. After four weeks, various parameters were assessed and compared within each group before and after the treatment. These parameters included echocardiographic indices (LVEF, LVESD, LVEDD, LVESV, and LVEDV), New York Heart Association (NYHA) cardiac function classification, ventricular remodeling markers (hs-CRP, TNF-α, NT-pro BNP, Gal-3, MMP-9, and TIMP-4), and the Six Minute Walk Distance (6MWD).

RESULTS

Both low-dose and high-dose Spironolactone significantly improved LVEF and 6MWD in HFIC patients (P<0.05), as well as markedly reduced LVESD, LVEDD, LVESV, LVEDV, and NYHA cardiac function grades (P<0.05). The high-dose group exhibited the most pronounced improvements (P<0.05). High-dose Spironolactone was more effective in improving the clinical and total effective rate compared to the low-dose, significantly reducing treatment inefficacy (P<0.05). Both dosages significantly increased serum potassium levels within normal ranges. They also improved the expression of ventricular remodeling markers (hs-CRP, TNF-α, NT-pro BNP, Gal-3, MMP-9, and TIMP-4) in HFIC patients, with the high-dose group showing the most significant results (P<0.05).

CONCLUSION

High-dose Spironolactone (60 mg/d) demonstrates superior efficacy over the low-dose (20 mg/d) in rapidly diminishing ventricular remodeling damage and enhancing cardiac function and clinical symptoms in HFIC patients over a short duration.

Aldosterone-progesterone relationship in sexually intact Chihuahua bitches

BACKGROUND

Aldosterone represents an important target of heart failure therapy and may be a valuable indicator of the renin-angiotensin-aldosterone system activity. However, its assessment might be challenging because of the effect of individual factors. In a recent study, intact female dogs showed the highest value of urinary aldosterone-to-creatinine ratio (UAldo:C) compared to other sex categories. In humans and rodents, an influence of progesterone has been reported by several studies. To our knowledge, the relationship between aldosterone and progesterone has not yet been investigated in dogs. The aim of this prospective study was to investigate this relationship in sexually intact Chihuahua females, measuring both hormones twice in the same bitch, that is in anoestrus when progesterone concentrations are baseline and in dioestrus when they are high.

RESULTS

The study population consisted of 14 sexually intact Chihuahua bitches. Serum progesterone (34.06 (21.17-44.90) vs. 0.19 [0.13-0.38] ng/ml; P < 0.001) and urinary aldosterone (9886.98 ± 5735.22 vs. 5005.72 ± 2127.73 pg/ml; P = 0.01) were significantly higher in dioestrus compared to anoestrous. Urinary aldosterone-to-creatinine ratio was higher in dioestrus compared to anoestrus (4.16 [3.17-6.80] vs. 3.39 ± 1.64 µg/g), but it did not reach the statistical significance (P = 0.056). Serum progesterone showed a moderate positive correlation with urinary aldosterone (ρ = 0.638, P < 0.001) and UAldo:C (ρ = 0.516, P = 0.005).

CONCLUSIONS

The results of the present study suggest the existence of a progesterone-aldosterone relationship in canine species, indicating that sex and phase of reproductive cycle should be taken into account when interpreting aldosterone concentrations. Further studies are needed to confirm these results on a larger canine population and to identify the underlying mechanisms in this species.

Importance of Micromilieu for Pathophysiologic Mineralocorticoid Receptor Activity-When the Mineralocorticoid Receptor Resides in the Wrong Neighborhood

The mineralocorticoid receptor (MR) is a member of the steroid receptor family and acts as a ligand-dependent transcription factor. In addition to its classical effects on water and electrolyte balance, its involvement in the pathogenesis of cardiovascular and renal diseases has been the subject of research for several years. The molecular basis of the latter has not been fully elucidated, but an isolated increase in the concentration of the MR ligand aldosterone or MR expression does not suffice to explain long-term pathologic actions of the receptor. Several studies suggest that MR activity and signal transduction are modulated by the surrounding microenvironment, which therefore plays an important role in MR pathophysiological effects. Local changes in micromilieu, including hypoxia, ischemia/reperfusion, inflammation, radical stress, and aberrant salt or glucose concentrations affect MR activation and therefore may influence the probability of unphysiological MR actions. The surrounding micromilieu may modulate genomic MR activity either by causing changes in MR expression or MR activity; for example, by inducing posttranslational modifications of the MR or novel interaction with coregulators, DNA-binding sites, or non-classical pathways. This should be considered when developing treatment options and strategies for prevention of MR-associated diseases.

Effects of mineralocorticoid receptor antagonist eplerenone on cardiac sympathetic nerve activity and left ventricular remodeling after reperfusion therapy in patients with first ST-segment elevation myocardial infarction

PURPOSE

The activation of the renin-angiotensin-aldosterone system prevents the uptake of norepinephrine and promotes structural remodeling of the heart. The mineralocorticoid receptor antagonist (MRA) eplerenone prevents left ventricular (LV) remodeling in patients with acute myocardial infarction, but its influence on cardiac sympathetic nerve activity (CSNA) has not been determined.

METHODS

We retrospectively evaluated the first ST-segment elevation myocardial infarction (STEMI) patients in our database who underwent 123I-metaiodobenzylguanidine (MIBG) scintigraphy 3 weeks after admission. Eighty-four STEMI patients after primary coronary angioplasty were selected, and used propensity score matching to compare patients who treated with MRA (N = 42), and those who did not (N = 42). The LV end-diastolic volume, end-systolic volume, and ejection fraction were determined by echocardiography, and plasma procollagen type III amino terminal peptide (PIIINP) was measured before and 3 weeks after treatment. The delayed total defect score (TDS), delayed heart/mediastinum count (H/M) ratio, and washout rate (WR) were determined using 123I-MIBG scintigraphy after 3 weeks.

RESULTS

Following primary angioplasty, age, gender, risk factors, culprit coronary artery, peak serum creatine phosphokinase concentration, and recanalization time were similar in the two groups. However, the MRA group showed significantly lower TDS and WR values (TDS: 22.8 ± 8.1 vs 32.2 ± 11.5, P < 0.005; WR: 31.1 ± 9.0% vs 42.7 ± 9.9%, P < 0.001) and a significantly higher H/M ratio (2.23 ± 0.41 vs 2.03 ± 0.36, P < 0.05) than the non-MRA group. The degree of change in LV parameters, and PIIINP were more favorable in the MRA group than in the non-MRA group. Moreover, multiple linear regression analyses revealed that both WR and not MRA treatment were significant predictor for LV remodeling, along with PIIINP concentrations.

CONCLUSION

Administration of eplerenone improves CSNA and prevents LV remodeling in patients with a first STEMI.

Effect of fibulin-5 on aldosterone-induced apoptosis in human ascending aortic smooth muscle cells

The aim of the current study was to investigate the effect of aldosterone on apoptosis in human aortic smooth muscle cells (HA-VSMC) and to determine the role of fibulin-5 in the aldosterone-induced apoptosis of HA-VSMC cells. Through the construction of a fibulin-5 eukaryotic overexpression vector and a short hairpin RNA interference plasmid, fibulin-5 was overexpressed and silenced, respectively. The role of fibulin-5 in the aldosterone-induced apoptosis of HA-VSMC was subsequently determined. The overexpression of fibulin-5 inhibited the apoptosis of cells, particularly at low concentrations of aldosterone; a smaller effect on apoptosis was induced by high concentrations of aldosterone. fibulin-5 knockdown promoted the apoptosis of cells induced by high concentrations of aldosterone but had a smaller effect on the apoptosis of cells induced by low concentrations of aldosterone. Therefore, the results of the current study indicate that fibulin-5 inhibits the aldosterone-induced apoptosis of HA-VSMC cells and that this effect may be altered by changing the aldosterone concentration.

Renal Injuries in Primary Aldosteronism: Quantitative Histopathological Analysis of 19 Patients With Primary Adosteronism

[Figure: see text].

Factors affecting the urinary aldosterone-to-creatinine ratio in healthy dogs and dogs with naturally occurring myxomatous mitral valve disease

BACKGROUND

Chronic renin-angiotensin-aldosterone system (RAAS) activation in course of heart diseases contributes to cardiac remodeling and heart failure. Myxomatous mitral valve disease (MMVD) is characterized by different stages of severity and trend of RAAS activity during the course of the disease is still uncertain. The urinary aldosterone-to-creatinine ratio (UAldo:C) has been proven to reflect RAAS activation in dogs and might be a useful marker in monitoring therapy and disease progression, but data about this parameter need to be expanded. The objective of this study was to evaluate the UAldo:C in healthy dogs and dogs with naturally occurring MMVD, and to investigate the relationships between this parameter and clinical, echocardiographic and laboratory variables.

RESULTS

The study population consisted of 149 dogs: 49 healthy and 100 MMVD dogs (45 stage B1, 13 stage B2 and 42 stage C). Urinary aldosterone-to-creatinine ratio was not significantly different among healthy and MMVD dogs of any stages. Breed, sex and age showed a significant impact on UAldo:C. In particular, Chihuahua and Cavalier King Charles spaniel showed significantly higher UAldo:C than other breeds, as well as intact females than other genders. In stage C dogs, UAldo:C appeared to be increased by spironolactone and was positively associated with furosemide dose (P = 0.024). Aldosterone breakthrough (ABT) appeared to occur in 36% (8/22) of stage C dogs not receiving spironolactone. A significant positive association between UAldo:C and left atrium-to-aortic root ratio (LA/Ao) was found.

CONCLUSIONS

Individual factors such as breed, sex and age appeared to influence UAldo:C, and therapy seemed to add further variability. In the light of these results, comparing the UAldo:C of a single patient with a population-based reference value might lead to wrong interpretations and an individual monitoring should be considered. The prevalence of ABT in the present study (36%) was in line with those previously reported. However, due to the high individual variability of UAldo:C found in the study, even this result should be re-evaluated in the setting of an individual longitudinal approach. The positive association between UAldo:C and LA/Ao supports the mutual relationship between RAAS and cardiac remodeling.

Role of Aldosterone and Mineralocorticoid Receptor in Cardiovascular Aging

The mineralocorticoid receptor (MR) was originally identified as a regulator of blood pressure, able to modulate renal sodium handling in response to its principal ligand aldosterone. MR is expressed in several extra-renal tissues, including the heart, vasculature, and adipose tissue. More recent studies have shown that extra-renal MR plays a relevant role in the control of cardiovascular and metabolic functions and has recently been implicated in the pathophysiology of aging. MR activation promotes vasoconstriction and acts as a potent pro-fibrotic agent in cardiovascular remodeling. Aging is associated with increased arterial stiffness and vascular tone, and modifications of arterial structure and function are responsible for these alterations. MR activation contributes to increase blood pressure with aging by regulating myogenic tone, vasoconstriction, and vascular oxidative stress. Importantly, aging represents an important contributor to the increased prevalence of cardiometabolic syndrome. In the elderly, dysregulation of MR signaling is associated with hypertension, obesity, and diabetes, representing an important cause of increased cardiovascular risk. Clinical use of MR antagonists is limited by the adverse effects induced by MR blockade in the kidney, raising the risk of hyperkalaemia in older patients with reduced renal function. Therefore, there is an unmet need for the enhanced understanding of the role of MR in aging and for development of novel specific MR antagonists in the context of cardiovascular rehabilitation in the elderly, in order to reduce relevant side effects.

Improvement of Cardiac Function by Laparoscopic Adrenalectomy in a Patient with Severe Heart Failure Attributable to Primary Aldosteronism

Aldosterone affects various systems and organs, including the cardiovascular system, through mineralocorticoid receptors. We here report a primary aldosteronism patient with severe cardiac dysfunction who showed dramatic improvement after laparoscopic adrenalectomy. The 57-year-old man presented with acute heart failure exacerbation. Performance status was 4, and New York Heart Association classification was 4. Echocardiography showed diffuse hypokinetic wall motion with an ejection fraction of 20%. The patient was found to have a high plasma level of brain natriuretic peptide (4,935 pg/mL), hypokalemia (2.7 mEq/L), an extremely elevated plasma aldosterone concentration (1,804 pg/mL), and high aldosterone-to-renin ratio [plasma aldosterone concentration (pg/mL)/plasma renin activity (ng/mL/hr)] (9,002). Computed tomography revealed a tumor 42 mm in diameter in the right adrenal gland. Primary aldosteronism was diagnosed with adrenal venous sampling. Medical treatment for heart failure was continued for several months, but the cardiac function was not sufficiently improved, suggesting the indication of heart transplantation. However, the patient could not be considered a candidate because of the adrenal tumor. Laparoscopic adrenalectomy was therefore performed. Immediately after surgery, echocardiography showed improved wall motion with an ejection fraction of 36%. Performance status and New York Heart Association classification were improved to 0 and 2, respectively. The present case has shown the efficacy of laparoscopic adrenalectomy for primary aldosteronism patients with severe heart failure.

Cyp2c44 gene disruption exacerbated pulmonary hypertension and heart failure in female but not male mice

Epoxyeicosatrienoicacids (EETs), synthesized from arachidonic acid by epoxygenases of the CYP2C and CYP2J gene subfamilies, contribute to hypoxic pulmonary vasoconstriction (HPV) in mice. Despite their roles in HPV, it is controversial whether EETs mediate or ameliorate pulmonary hypertension (PH). A recent study showed that deficiency of Cyp2j did not protect male and female mice from hypoxia-induced PH. Since CYP2C44 is a functionally important epoxygenase, we hypothesized that knockout of the Cyp2c44 gene would protect both sexes of mice from hypoxia-induced PH. We tested this hypothesis in wild-type (WT) and Cyp2c44 knockout (Cyp2c44 (-/-)) mice exposed to normoxia (room air) and hypoxia (10% O2) for 5 weeks. Exposure of WT and Cyp2c44 (-/-) mice to hypoxia resulted in pulmonary vascular remodeling, increased pulmonary artery resistance, and decreased cardiac function in both sexes. However, in female Cyp2c44 (-/-) mice, compared with WT mice, (1) pulmonary artery resistance and right ventricular hypertrophy were greater, (2) cardiac index was lower, (3) left ventricular and arterial stiffness were higher, and (4) plasma aldosterone levels were higher, but (5) there was no difference in levels of EET in lungs and heart. Paradoxically and unexpectedly, we found that Cyp2c44 disruption exacerbated hypoxia-induced PH in female but not male mice. We attribute exacerbated PH in female Cyp2c44 (-/-) mice to elevated aldosterone and as-yet-unknown systemic factors. Therefore, we suggest a role for the human CYP2C genes in protecting women from severe PH and that this could be one of the underlying causes for a better 5-year survival rate in women than in men.

Association between long-term prescription of aldosterone antagonist and the progression of heart failure with preserved ejection fraction in hypertensive patients

BACKGROUND

Hypertension complicated with left ventricular hypertrophy (LVH) and diastolic dysfunction is independently related to increasing risk of subsequent incident heart failure with preserved ejection fraction (HFpEF). This study was designed to evaluate the influences of long-term aldosterone antagonist prescription in these patients.

METHODS

Using a propensity score matching of 1:2 ratio, this retrospective claims database study compared spironolactone prescription (n=65) and non-spironolactone therapy (n=130) in hypertensive patients with LVH [left ventricular mass index (LVMI)>125g/m(2) for men and >110g/m(2) for women] and suspected diastolic dysfunction (E/E' ratio between 8 and 15) and without clinical signs or symptoms of heart failure.

RESULTS

With a median follow-up of 7.4years, the new-onset symptomatic HFpEF occurred in 3 of 65 patients in the spironolactone group and 21 of 130 patients in the non-spironolactone group (P=0.021). Spironolactone also generated more prominent improvement in diastolic function and LVH. And multivariate logistic regression model revealed that spironolactone prescription (OR 0.177, 95% CI: 0.045-0.687, P=0.012) was associated with a reduced risk of new onset of symptomatic HFpEF, and the elevation of LVMI (OR 1.053, 95% CI: 1.011-1.097, P=0.012) or E/E' (OR 1.280, 95% CI: 1.015-1.615, P=0.037) was associated with a high risk of new onset of symptomatic HFpEF.

CONCLUSIONS

Long-term aldosterone antagonist exposure was associated with protective effects in terms of the incidence of new-onset symptomatic HFpEF, LV diastolic dysfunction and LVH in hypertensive patients, which might be beneficial for the delay of HFpEF progression.

Effects of spironolactone and losartan on the early neovascularization of acute myocardial infarction

The aim of the present study was to investigate the effects of spironolactone and losartan on the early healing stage of acute myocardial infarction (AMI) in rats. An AMI rat model was established and the rats were randomly divided into four groups: AMI (n=12), AMI + spironolactone (AMI + S; n=12), AMI + losartan (AMI + L; n=12) and AMI + spironolactone combined with losartan (AMI + S + L; n=12). Sham-operated rats served as a control group (n=12). The expression levels of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) in the non-infarcted myocardium surrounding the AMI area were determined using immunohistochemistry. In addition, the capillary density in the non-infarcted myocardium surrounding the AMI area was detected. The capillary densities around the infarcted area in the AMI and treatment groups at day 7 and 14 following AMI surgery were significantly higher compared with the sham-operated rats. Compared with the AMI group, the capillary densities around the infarcted area and the ratio of MMPs/TIMP-1 were increased in the treatment groups following AMI surgery; however, the increased ratio of MMPs/TIMP-1 was reduced at day 14 following AMI surgery. Therefore, these results indicated that spironolactone and losartan may promote the formation of collateral circulation in the non-infarcted tissue surrounding the infarcted area by regulating the production of MMPs.

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

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

Cardiovascular pathophysiology in chronic kidney disease: opportunities to transition from disease to health

BACKGROUND

Chronic kidney disease (CKD) is common, and is associated with a high burden of cardiovascular disease. This cardiovascular risk is incompletely explained by traditional risk factors, calling attention to a need to better understand the pathways in CKD contributing to adverse cardiovascular outcomes.

FINDINGS

Pathophysiological derangements associated with CKD, including disordered sodium, potassium, and water homeostasis, renin-angiotensin-aldosterone and sympathetic activity, anemia, bone and mineral metabolism, uremia, and toxin accumulation may contribute directly to progression of cardiovascular disease and adverse outcomes.

CONCLUSION

Improving cardiovascular health in patients with CKD requires improved understanding of renocardiac pathophysiology. Ultimately, the most successful strategy may be prevention of incident CKD itself.

Should there be sex-specific criteria for the diagnosis and treatment of heart failure?

All-cause mortality from cardiovascular disease is declining in the USA. However, there remains a significant difference in risk factors for disease and in mortality between men and women. For example, prevalence and outcomes for heart failure with preserved ejection fraction differ between men and women. The reasons for these differences are multifactorial, but reflect, in part, an incomplete understanding of sex differences in the etiology of cardiovascular diseases and a failure to account for sex differences in pre-clinical studies including those designed to develop new diagnostic and treatment modalities. This review focuses on the underlying physiology of these sex differences and provides evidence that inclusion of female animals in pre-clinical studies of heart failure and in development of imaging modalities to assess cardiac function might provide new information from which one could develop sex-specific diagnostic criteria and approaches to treatment.

The past, present and future of renin-angiotensin aldosterone system inhibition

The renin-angiotensin aldosterone system (RAAS) is central to the pathogenesis of cardiovascular disease. RAAS inhibition can reduce blood pressure, prevent target organ damage in hypertension and diabetes, and improve outcomes in patients with heart failure and/or myocardial infarction. This review presents the history of RAAS inhibition including a summary of key heart failure, myocardial infarction, hypertension and atrial fibrillation trials. Recent developments in RAAS inhibition are discussed including implementation and optimization of current drug therapies. Finally, ongoing clinical trials, opportunities for future trials and issues related to the barriers and approvability of novel RAAS inhibitors are highlighted.

Mineralocorticoid receptor antagonists for heart failure with reduced ejection fraction: integrating evidence into clinical practice

Mineralocorticoid receptor antagonists (MRAs) improve survival and reduce morbidity in patients with heart failure, reduced ejection fraction (HF-REF), and mild-to-severe symptoms, and in patients with left ventricular systolic dysfunction and heart failure after acute myocardial infarction. These clinical benefits are observed in addition to those of angiotensin converting enzyme inhibitors or angiotensin receptor blockers and beta-blockers. The morbidity and mortality benefits of MRAs may be mediated by several proposed actions, including antifibrotic mechanisms that slow heart failure progression, prevent or reverse cardiac remodelling, or reduce arrhythmogenesis. Both eplerenone and spironolactone have demonstrated survival benefits in individual clinical trials. Pharmacologic differences exist between the drugs, which may be relevant for therapeutic decision making in individual patients. Although serious hyperkalaemia events were reported in the major MRA clinical trials, these risks can be mitigated through appropriate patient selection, dose selection, patient education, monitoring, and follow-up. When used appropriately, MRAs significantly improve outcomes across the spectrum of patients with HF-REF.