Mineralocorticoid receptor antagonism improves diastolic dysfunction in chronic kidney disease in mice

Benefit of combination therapy with dapagliflozin and eplerenone on cardiac function and fibrosis in rats with non-diabetic chronic kidney disease

Patients with chronic kidney disease (CKD) are at a high risk of cardiovascular (CV) complications. In these patients, sodium-glucose cotransporter-2 inhibitors (SGLT2i) have been shown to reduce CV events. Mineralocorticoid receptor antagonists (MRAs) exert similar benefits in diabetic CKD, though their effects in non-diabetic CKD remain unclear. This study aimed to evaluated whether the combination of Dapagliflozin (DAPA) and Eplerenone (EPLE) would have positive effects on cardiorenal functions in a non-diabetic CKD model. CKD was induced in rats via 5/6 nephrectomy, followed by treatment with DAPA (5 mg/kg/day PO), EPLE (100 mg/kg/day PO) or the combination for 3 months following CKD induction. Cardiorenal functions were assessed after the treatment period. All treated groups showed reduced kidney fibrosis though plasma creatinine and urea levels remained unchanged. Compared to untreated CKD, EPLE or DAPA/EPLE reduced left ventricle (LV) end-diastolic pressure and LV end-diastolic pressure volume relationship, whereas DAPA alone did not achieve significant reductions. Compared to untreated CKD, EPLE and DAPA/EPLE improved cardiac perfusion but DAPA alone did not. Cardiac fibrosis in CKD was blunted by either DAPA or EPLE alone, with the combination showing an additive effect. In conclusion, co-treatment with DAPA and EPLE enhances diastolic function, cardiac perfusion and reduces myocardial fibrosis in non-diabetic CKD rats.

Renal and cardiovascular prognostic significance of echocardiographic early diastolic mitral annular velocity in IgA nephropathy

In chronic kidney disease (CKD), as in IgA nephropathy (IgAN), cardiovascular (CV) mortality and morbidity are many times higher than in the general population, and diastolic dysfunction (LVDD) has prognostic significance as well. Tissue Doppler Echocardiography (TDI) is another method for measuring myocardial contractility and determining diastolic dysfunction. 79 IgAN patients (age 46 ± 11 years) with CKD stages 1-3 were investigated and followed for 70 ± 28.7 months. Doppler echocardiography was used to measure the E (early) and A (late) waves, as well as the E wave deceleration time (EDT) during mitral inflow. TDI was used to measure early (Ea) and late (Aa) diastolic velocities (lateral and septal basal wall fragment average). From these, we calculated the E/Ea and Ea/Aa ratios. The primary combined endpoints were total mortality, major CV events, and end-stage renal disease, and the secondary endpoints were cardiovascular or renal (eGFR decreased below 15 ml/min/1.73 m2 or renal replacement therapy was started). Patients with decreased Ea (< 13 cm/s) had significantly more endpoints (20/42 vs. 3/37; p = 0.001) than patients with higher Ea (≥ 13 cm/s). The secondary renal endpoints were also significantly higher (p = 0.004). In a multivariate model, the eGFR showed independent correlation with the E/A ratio (r = 0.466; p < 0.01), EDT (r = - 0.270; p < 0.01), Ea/Aa ratio (r = 0.455; p < 0.01), and decreased Ea (r = 0.544; p < 0.01). Independent factors influencing Ea were only EDT by uni- and multivariate regression but age and albuminuria by logistic regression. Decreased Ea measured by TDI seems to be an eligible factor to predict the prognosis of IgA nephropathy. The decreased Ea may be a helpful parameter to identify high-risk CKD patients.

The role of a novel mineralocorticoid receptor antagonist, finerenone, in chronic kidney disease: mechanisms and clinical advances

BACKGROUND

Chronic kidney disease (CKD) poses a significant health risk in contemporary society. Current CKD treatments primarily involve renin-angiotensin-aldosterone system inhibitors and mineralocorticoid receptor antagonists, albeit associated with hyperkalemia risks. A novel selective mineralocorticoid receptor antagonist, finerenone, offers a promising, safer alternative for CKD therapy. This review comprehensively assesses the role and efficacy of finerenone in CKD treatment by analyzing clinical and animal studies. Emerging evidence consistently supports finerenone's ability to effectively slow the progression of CKD. By targeting the mineralocorticoid receptor, finerenone not only mitigates renal damage but also exhibits a favorable safety profile, minimizing hyperkalemia concerns.

CONCLUSION

Finerenone emerges as a valuable addition to CKD therapy, demonstrating potential benefits in delaying CKD progression while minimizing side effects. Nevertheless, further clinical trials are necessary to provide a comprehensive understanding of its safety and efficacy.

Molecular pharmacology of mineralocorticoid receptor antagonists: The role of co-regulators

Mineralocorticoid receptor (MR) antagonists have shown remarkable benefits in the treatment of cardiovascular disease. However, their underutilization in clinical practice may be attributed to concerns regarding the risk of hyperkalemia. An ideal selective MR modulator would inhibit the detrimental effects of MR in non-epithelial cells of the cardiovascular system while sparing its physiological function in kidney epithelial cells, thereby reducing the risk of adverse events. To address this issue, a new generation of non-steroidal MR antagonists, including esaxereneone, balcinrenone, ocedurenone, and finerenone, has been developed with distinct molecular structures and pharmacology. They share a mechanism of action that is different from the previously developed steroidal MR antagonists, leading to altered co-regulator interaction, potentially involving conformational changes of the receptor. Interfering with MR co-regulator interaction or the co-regulator itself may enable selective targeting of downstream signaling cascades and - in the long term - lead to more personalized medicine. In this review article, we summarize what is currently known about the mechanisms of action of the different MR antagonists with a focus on MR co-factor interaction and what may be inferred from this for future developments.

Cardiomyopathy in chronic kidney disease: clinical features, biomarkers and the contribution of murine models in understanding pathophysiology

The cardiorenal syndrome (CRS) is described as a multi-organ disease encompassing bidirectionally heart and kidney. In CRS type 4, chronic kidney disease (CKD) leads to cardiac injury. Different pathological mechanisms have been identified to contribute to the establishment of CKD-induced cardiomyopathy, including a neurohormonal dysregulation, disturbances in the mineral metabolism and an accumulation of uremic toxins, playing an important role in the development of inflammation and oxidative stress. Combined, this leads to cardiac dysfunction and cardiac pathophysiological and morphological changes, like left ventricular hypertrophy, myocardial fibrosis and cardiac electrical changes. Given that around 80% of dialysis patients suffer from uremic cardiomyopathy, the study of cardiac outcomes in CKD is clinically highly relevant. The present review summarizes clinical features and biomarkers of CKD-induced cardiomyopathy and discusses underlying pathophysiological mechanisms recently uncovered in the literature. It discloses how animal models have contributed to the understanding of pathological kidney-heart crosstalk, but also provides insights into the variability in observed effects of CKD on the heart in different CKD mouse models, covering both "single hit" as well as "multifactorial hit" models. Overall, this review aims to support research progress in the field of CKD-induced cardiomyopathy.

Relationship between arterial stiffness, left ventricular diastolic function, and renal function in chronic kidney disease

AIM

In chronic kidney disease, IgA nephropathy, and left ventricular diastolic dysfunction have prognostic significance as well. However, the relationship between diastolic dysfunction, arterial stiffness, and renal function has not been fully elucidated.

METHODS

79 IgA nephropathy patients (aged 46 ± 11 years) and 50 controls were investigated. Tissue Doppler imaging was used to measure early (Ea) and late (Aa) diastolic velocities. Arterial stiffness was measured by a photoplethysmographic (stiffness index (SI)) and an oscillometric method (aortic pulse wave velocity (PWVao)).

RESULTS

We compared the IgAN patients to a similar cardiovascular risk group with a preserved eGFR. A strong correlation was found between Ea/Aa and SI (p < 0.001), also with PWVao (p < 0.001), just in IgAN, and with eGFR (p < 0.001) in both groups. IgAN patients were divided into groups CKD1-2 vs. CKD3-5. In the CKD 3-5 group, the incidence of diastolic dysfunction increased significantly: 39% vs. 72% (p = 0.003). Left ventricle rigidity (LVR) was calculated, which showed a close correlation with SI (p = 0.009) and eGFR (p = 0.038). By linear regression analysis, the independent predictors of SI were age, E/A, and E/Ea; SI was the predictor of LVR; and E/A and hypertension were the predictors of eGFR.

CONCLUSION

In chronic kidney disease, increased cardiac rigidity and vascular stiffness coexist with decreased renal function, which is directly connected to diastolic dysfunction and vascular stiffness. On the basis of comparing the CKD group to the control group, vascular alterations in very early CKD can be identified.

Effects of Finerenone on Cardiovascular and Chronic Kidney Diseases: A New Weapon against Cardiorenal Morbidity and Mortality-A Comprehensive Review

Patients with cardiovascular disease (CVD) and chronic kidney disease (CKD) show high rates of cardiorenal outcomes. In addition, the progression towards renal failure and cardiovascular events rises as CKD worsens. Several studies suggest that the activation of the mineralocorticoid receptor (MR) induces cardiac and renal injury, including inflammation and fibrosis. Finerenone is a novel, nonsteroidal, selective MR antagonist (MRA) which has demonstrated anti-inflammatory and anti-fibrotic effects in pre-clinical studies. Moreover, two large trials (FIDELIO-DKD and FIGARO-DKD) investigated the renal and cardiovascular outcomes in patients with mild to severe CKD in type 2 diabetes which received finerenone. On these bases, this comprehensive review aims to summarize the current knowledge regarding finerenone and its effects on CKD and the cardiovascular system, emphasizing its role in modifying cardiorenal outcomes.

Benefits of the Non-Steroidal Mineralocorticoid Receptor Antagonist Finerenone in Metabolic Syndrome-Related Heart Failure with Preserved Ejection Fraction

The mineralocorticoid receptor (MR) plays an important role in the development of chronic kidney disease (CKD) and associated cardiovascular complications. Antagonizing the overactivation of the MR with MR antagonists (MRA) is a therapeutic option, but their use in patients with CKD is limited due to the associated risk of hyperkalemia. Finerenone is a non-steroidal MRA associated with an improved benefit-risk profile in comparison to steroidal MRAs. In this study, we decided to test whether finerenone improves renal and cardiac function in male hypertensive and diabetic ZSF1 rats as an established preclinical HFpEF model. Finerenone was administered at 10 mg/kg/day for 12 weeks. Cardiac function/hemodynamics were assessed in vivo. ZSF1 rats showed classical signs of CKD with increased BUN, UACR, hypertrophy, and fibrosis of the kidney together with characteristic signs of HFpEF including cardiac fibrosis, diastolic dysfunction, and decreased cardiac perfusion. Finerenone treatment did not impact kidney function but reduced renal hypertrophy and cardiac fibrosis. Interestingly, finerenone ameliorated diastolic dysfunction and cardiac perfusion in ZSF1 rats. In summary, we show for the first time that non-steroidal MR antagonism by finerenone attenuates cardiac diastolic dysfunction and improves cardiac perfusion in a preclinical HFpEF model. These cardiac benefits were found to be largely independent of renal benefits.

Potential Impact of Non-Steroidal Mineralocorticoid Receptor Antagonists in Cardiovascular Disease

Inappropriate mineralocorticoid receptor (MR) activation in different cardiovascular cell types has deleterious effects on cardiac remodeling and function. Therefore, MR inhibition is a crucial pharmacological strategy to overcome cardiovascular dysfunction. Despite efficient blockade of MR with steroidal MR antagonists (MRAs), their clinical application is unsatisfactory due to the adverse effects. Newer non-steroidal MRAs with greater potency could be suitable for clinical application, especially in patients with type 2 diabetes mellitus and chronic kidney disease. Although clinical evidence has shown the beneficial effects of non-steroidal MRAs on cardiovascular outcomes in patients with heart failure with reduced ejection fraction, clinical trials are ongoing to evaluate the efficacy of heart failure with preserved ejection fraction. Therefore, comparative pharmacological characterization of non-steroidal MRAs over classic steroidal MRAs is crucial. Here, we summarize the pre-clinical evidence of non-steroidal MRAs, which suggests an improvement in cardiac dysfunction, as well as the underlying molecular mechanisms in animal models mimicking different clinical conditions. In addition, we discuss up-to-date information from clinical trials regarding the beneficial effects of non-steroidal MRAs on meaningful cardiovascular outcomes. Both pre-clinical and clinical evidence support treatment with non-steroidal MRAs in patients with cardiovascular disease.

Effects of Finerenone, a Novel Nonsteroidal Mineralocorticoid Receptor Antagonist, on Cardiovascular Disease, Chronic Kidney Disease, and Blood Pressure

PURPOSE OF REVIEW

Finerenone, an FDA-approved nonsteroidal mineralocorticoid receptor (MR) antagonist, has been evaluated in context of chronic kidney disease (CKD) and associated cardiovascular disease (CVD). In this review, we summarize pre-clinical and clinical studies focused on the impact of finerenone on these disease processes.

RECENT FINDINGS

Activation of the MR upregulates genes encoding for facilitators of tissue damage. Finerenone binding to a helix domain in this receptor inhibits receptor function. Studies in murine models of kidney disease, heart failure, hypertension, and vascular injury demonstrate significant protective effects of finerenone against further disease progression, as well as association with reduced oxidative stress, inflammation, and fibrosis. Phase 1-3 clinical trials with finerenone show safety and efficacy in improving renal and cardiovascular outcomes in patients with CKD. Research thus far encourages the addition of finerenone to the standard of care for certain CKD patients, especially those especially at risk for or with pre-existing cardiovascular disease. Continued study of the effect of finerenone in diverse patient populations and different disease states is needed.

The non-steroidal mineralocorticoid receptor antagonist finerenone is a novel therapeutic option for patients with Type 2 diabetes and chronic kidney disease

Despite strong preclinical data supporting the use of mineralocorticoid receptor antagonists (MRAs) to provide cardiorenal protection in rodent models of diabetes, the clinical evidence of their utility in treating chronic kidney disease (CKD) has been limited. Two major clinical trials (FIDELIO-DKD and FIGARO-DKD) including more than 13,000 patients with albuminuric CKD and Type 2 diabetes randomized to placebo or finerenone (MRA) have recently provided exciting results showing a significant risk reduction for kidney and cardiovascular outcomes. In this review, we will summarize the major findings of these trials, together with post-hoc and pooled analyses that have allowed evaluation of the efficacy and safety of finerenone across the spectrum of CKD, revealing significant protective effects of finerenone against kidney failure, new-onset atrial fibrillation or flutter, new-onset heart failure, cardiovascular death, and first and total heart-failure hospitalizations. Moreover, we will discuss the current evidence that supports the combined use of MRAs with sodium-glucose co-transporter-2 inhibitors, either by providing an additive cardiorenal benefit or by decreasing the risk of hyperkalemia. Although the mechanisms of protection by finerenone have only been partially explored in patients, rodent studies have shed light on its anti-inflammatory and anti-fibrotic effects in models of kidney disease, which is one of the main drivers for testing the efficacy of finerenone in non-diabetic CKD patients in the ongoing FIND-CKD trial.

Mineralocorticoid Receptor Antagonism Prevents the Synergistic Effect of Metabolic Challenge and Chronic Kidney Disease on Renal Fibrosis and Inflammation in Mice

Obesity and/or metabolic diseases are frequently associated with chronic kidney disease and several factors associated with obesity may contribute to proteinuria and extracellular matrix production. Mineralocorticoid receptor antagonists have proven their clinical efficacy in diabetic kidney disease with preclinical data suggesting that they may also be efficient in non-diabetic chronic kidney disease associated to metabolic diseases. In the present study we developed a novel mouse model combining severe nephron reduction and High Fat Diet challenge that led to chronic kidney disease with metabolic alterations. We showed that the Mineralocorticoid Receptor antagonist canrenoate improved metabolic function, reduced albuminuria and prevented the synergistic effect of high fat diet on renal fibrosis and inflammation in chronic kidney disease mice.

Roles of Mineralocorticoid Receptors in Cardiovascular and Cardiorenal Diseases

Mineralocorticoid receptor (MR) activation in the heart and vessels leads to pathological effects, such as excessive extracellular matrix accumulation, oxidative stress, and sustained inflammation. In these organs, the MR is expressed in cardiomyocytes, fibroblasts, endothelial cells, smooth muscle cells, and inflammatory cells. We review the accumulating experimental and clinical evidence that pharmacological MR antagonism has a positive impact on a battery of cardiac and vascular pathological states, including heart failure, myocardial infarction, arrhythmic diseases, atherosclerosis, vascular stiffness, and cardiac and vascular injury linked to metabolic comorbidities and chronic kidney disease. Moreover, we present perspectives on optimization of the use of MR antagonists in patients more likely to respond to such therapy and review the evidence suggesting that novel nonsteroidal MR antagonists offer an improved safety profile while retaining their cardiovascular protective effects. Finally, we highlight future therapeutic applications of MR antagonists in cardiovascular injury.

Mineralocorticoid receptor antagonists in diabetic kidney disease - mechanistic and therapeutic effects

Chronic kidney disease (CKD) is the leading complication in type 2 diabetes (T2D) and current therapies that limit CKD progression and the development of cardiovascular disease (CVD) include angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers and sodium-glucose co-transporter 2 (SGLT2) inhibitors. Despite the introduction of these therapeutics, an important residual risk of CKD progression and cardiovascular death remains in patients with T2D. Mineralocorticoid receptor antagonists (MRAs) are a promising therapeutic option in diabetic kidney disease (DKD) owing to the reported effects of mineralocorticoid receptor activation in inflammatory cells, podocytes, fibroblasts, mesangial cells and vascular cells. In preclinical studies, MRAs consistently reduce albuminuria, CKD progression, and activation of fibrotic and inflammatory pathways. DKD clinical studies have similarly demonstrated that steroidal MRAs lead to albuminuria reduction compared with placebo, although hyperkalaemia is a major secondary effect. Non-steroidal MRAs carry a lower risk of hyperkalaemia than steroidal MRAs, and the large FIDELIO-DKD clinical trial showed that the non-steroidal MRA finerenone also slowed CKD progression and reduced the risk of adverse cardiovascular outcomes compared with placebo in patients with T2D. Encouragingly, other non-steroidal MRAs have anti-albuminuric properties in DKD. Whether or not combining MRAs with other renoprotective drugs such as SGLT2 inhibitors might provide additive protective effects warrants further investigation.

Associations Between Myocardial Diastolic Dysfunction and Cardiovascular Mortality in Chronic Kidney Disease: A Large Single-Center Cohort Study

BACKGROUND

The clinical burden and prognostic role of diastolic dysfunction (DD), based on the latest American Society of Echocardiography (ASE) 2016 guidelines, remains unclear in patients with chronic kidney disease (CKD). Moreover, risk mapping of concomitant systolic dysfunction and DD to evaluate the hazard of cardiovascular (CV) mortality in CKD remains unexplored.

METHODS

This retrospective cohort study identified 20,257 adult patients who underwent comprehensive echocardiography between 2008 and 2016 at a tertiary medical center in central Taiwan. The patients were stratified by CKD stage, and the 3-year CV mortality risk in each CKD stratum was estimated through multivariable Cox proportional hazard modeling using left ventricular ejection fraction (LVEF) and DD grades based on ASE 2016 guideline as the main risk factors.

RESULTS

Compared with patients with CKD stages 1 and 2, those with CKD stages 4 and 5 had a significantly lower LVEF and more severe DD. Both LVEF (LVEF < 40% vs. ≥ 60%; adjusted hazard ratio [aHR] 3.17, 95% confidence interval [CI] 2.54-3.97) and DD grade (severe DD vs. normal diastolic function; aHR 3.33, 95% CI 2.33-4.76) were independently associated with 3-year CV mortality in the entire study population and had comparable effect sizes. The corresponding aHRs further increased to 4.20 (2.45-7.21) and 4.54 (2.20-9.38) in patients with CKD stages 4 and 5. Systolic and diastolic dysfunction demonstrated mutually augmentative effects on CV mortality.

CONCLUSIONS

These findings suggest that the current practice of cardioprotection for patients with CKD should be prioritized at an early stage along with conventional nephroprotection.

The Role of the Mineralocorticoid Receptor and Mineralocorticoid Receptor-Directed Therapies in Heart Failure

Mineralocorticoid receptor (MR) antagonists (MRA), also referred to as aldosterone blockers, are now well-recognized for their clinical benefit in patients who have heart failure (HF) with reduced ejection fraction (HFrEF). Recent studies have also shown MRA can improve outcomes in patients with HFpEF, where the ejection fraction is preserved but left ventricular filling is reduced. While the MR is a steroid hormone receptor best known for antinatriuretic actions on electrolyte homeostasis in the distal nephron, it is now established that the MR has many physiological and pathophysiological roles in the heart, vasculature, and other nonepithelial tissue types. It is the impact of MR activation on these tissues that underpins the use of MRA in cardiovascular disease, in particular HF. This mini-review will discuss the origins and the development of MRA and highlight how their use has evolved from the "potassium-sparing diuretics" spironolactone and canrenone over 60 years ago, to the more receptor-selective eplerenone and most recently the emergence of new nonsteroidal receptor antagonists esaxerenone and finerenone.

Mineralocorticoid receptor in cardiovascular diseases-Clinical trials and mechanistic insights

Aldosterone binds to the mineralocorticoid receptor (NR3C2), a transcription factor of the nuclear receptor family, present in the kidney and in various other non-epithelial cells including the heart and the vasculature. Indeed, extra-renal pathophysiological effects of this hormone have been characterized, extending its actions to the cardiovascular system. A growing body of clinical and pre-clinical evidence suggests that mineralocorticoid receptor overactivation plays an important pathophysiological role in cardiovascular remodelling by promoting cardiac hypertrophy, fibrosis, arterial stiffness and in inflammation and oxidative stress. The following review article outlines the role of mineralocorticoid receptor in cardiovascular disease with a focus on myocardial remodelling and heart failure (HF) including clinical trials as well as cellular and animal studies.

Finerenone: First Approval

Finerenone (Kerendia^®), a first-in-class, orally administered, selective, nonsteroidal mineralocorticoid receptor antagonist (MRA), is being developed by Bayer HealthCare Pharmaceuticals for the treatment of diabetic kidney disease (DKD) and heart failure (HF), including chronic HF (CHF). Finerenone has been approved in the USA to reduce the risk of sustained estimated glomerular filtration rate (eGFR) decline, end stage renal disease (ESRD), cardiovascular death, nonfatal myocardial infarction (MI), and hospitalization for HF in adults with chronic kidney disease (CKD) associated with type 2 diabetes (T2D). Finerenone is undergoing regulatory assessment in the EU and in China. A phase III trial is investigating finerenone in patients who have HF with preserved ejection fraction. This article summarizes the milestones in the development of finerenone leading to this first approval to reduce the risk of serious kidney and heart complications in adults with CKD and T2D.

The Role of Finerenone in the Management of Diabetic Nephropathy

Diabetic nephropathy (DN) is the leading cause of chronic kidney disease. Even though mineralocorticoid receptor antagonists (MRA) induce incremental reductions in urine albumin excretion when added to angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, this combination is infrequently used because of an increased risk of hyperkalemia. In this context, finerenone, a novel selective MRA that appears to be associated with lower risk for hyperkalemia compared with other MRAs (spironolactone and eplerenone), might represent a useful tool in patients with DN. A recent large randomized trial suggested that finerenone delays the progression of DN and might also reduce cardiovascular morbidity in patients with DN. However, more data are needed to clarify the safety and efficacy of finerenone in this high-risk population.

Mineralocorticoid receptor blockade with finerenone improves heart function and exercise capacity in ovariectomized mice

AIMS

In post-menopausal women, incidence of heart failure with preserved ejection fraction is higher than in men. Hormonal replacement therapies did not demonstrate benefits. We tested whether the non-steroidal mineralocorticoid receptor antagonist finerenone limits the progression of heart failure in ovariectomized (OVX) mice with metabolic disorders.

METHODS AND RESULTS

Ovariectomy was performed in 4-month-old mice, treated or not at 7 months old for 1 month with finerenone (Fine) 1 mg/kg/day. Left ventricular (LV) cardiac and coronary endothelial functions were assessed by echocardiography, catheterization, and myography. Blood pressure was measured by plethysmography. Insulin and glucose tolerance tests were performed. Exercise capacity and spontaneous activity were measured on treadmill and in combined indirect calorimetric cages equipped with voluntary running wheel. OVX mice presented LV diastolic dysfunction without modification of ejection fraction compared with controls (CTL), whereas finerenone improved LV filling pressure (LV end-diastolic pressure, mmHg: CTL 3.48 ± 0.41, OVX 6.17 ± 0.30**, OVX + Fine 3.65 ± 0.55† , **P < 0.01 vs. CTL, † P < 0.05 vs. OVX) and compliance (LV end-diastolic pressure-volume relation, mmHg/RVU: CTL 1.65 ± 0.42, OVX 4.77 ± 0.37***, OVX + Fine 2.87 ± 0.26†† , ***P < 0.001 vs. CTL, †† P < 0.01 vs. OVX). Acetylcholine-induced endothelial-dependent relaxation of coronary arteries was impaired in ovariectomized mice and improved by finerenone (relaxation, %: CTL 86 ± 8, OVX 38 ± 3**, OVX + Fine 83 ± 7†† , **P < 0.01 vs. CTL, †† P < 0.01 vs. OVX). Finerenone improved decreased ATP production by subsarcolemmal mitochondria after ovariectomy. Weight gain, increased blood pressure, and decreased insulin and glucose tolerance in OVX mice were improved by finerenone. The exercise capacity at race was diminished in untreated OVX mice only. Spontaneous activity measurements in ovariectomized mice showed decreased horizontal movements, reduced time spent in a running wheel, and reduced VO2 and VCO2 , all parameters improved by finerenone.

CONCLUSIONS

Finerenone improved cardiovascular dysfunction and exercise capacity after ovariectomy-induced LV diastolic dysfunction with preserved ejection fraction.

Cardioprotective Effects of a Nonsteroidal Mineralocorticoid Receptor Blocker, Esaxerenone, in Dahl Salt-Sensitive Hypertensive Rats

We investigated the effects of esaxerenone, a novel, nonsteroidal, and selective mineralocorticoid receptor blocker, on cardiac function in Dahl salt-sensitive (DSS) rats. We provided 6-week-old DSS rats a high-salt diet (HSD, 8% NaCl). Following six weeks of HSD feeding (establishment of cardiac hypertrophy), we divided the animals into the following two groups: HSD or HSD + esaxerenone (0.001%, w/w). In survival study, all HSD-fed animals died by 24 weeks of age, whereas the esaxerenone-treated HSD-fed animals showed significantly improved survival. We used the same protocol with a separate set of animals to evaluate the cardiac function by echocardiography after four weeks of treatment. The results showed that HSD-fed animals developed cardiac dysfunction as evidenced by reduced stroke volume, ejection fraction, and cardiac output. Importantly, esaxerenone treatment decreased the worsening of cardiac dysfunction concomitant with a significantly reduced level of systolic blood pressure. In addition, treatment with esaxerenone in HSD-fed DSS rats caused a reduced level of cardiac remodeling as well as fibrosis. Furthermore, inflammation and oxidative stress were significantly reduced. These data indicate that esaxerenone has the potential to mitigate cardiac dysfunction in salt-induced myocardial injury in rats.

Aldosterone and the mineralocorticoid receptor in renal injury: A potential therapeutic target in feline chronic kidney disease

There is a growing body of experimental and clinical evidence supporting mineralocorticoid receptor (MR) activation as a powerful mediator of renal damage in laboratory animals and humans. Multiple pathophysiological mechanisms are proposed, with the strongest evidence supporting aldosterone-induced vasculopathy, exacerbation of oxidative stress and inflammation, and increased growth factor signalling promoting fibroblast proliferation and deranged extracellular matrix homeostasis. Further involvement of the MR is supported by extensive animal model experiments where MR antagonists (such as spironolactone and eplerenone) abrogate renal injury, including ischaemia-induced damage. Additionally, clinical trials have shown MR antagonists to be beneficial in human chronic kidney disease (CKD) in terms of reducing proteinuria and cardiovascular events, though current studies have not evaluated primary end points which allow conclusions to made about whether MR antagonists reduce mortality or slow CKD progression. Although differences between human and feline CKD exist, feline CKD shares many characteristics with human disease including tubulointerstitial fibrosis. This review evaluates the evidence for the role of the MR in renal injury and summarizes the literature concerning aldosterone in feline CKD. MR antagonists may represent a promising therapeutic strategy in feline CKD.

Updates in the management of heart failure for the chronic kidney disease patient

PURPOSE OF REVIEW

Heart failure is highly prevalent in patients with chronic kidney disease (CKD) and a leading cause of morbidity and mortality in this population. Heart failure therapies proven to benefit the general population may have different risk-benefit profiles in patients with concurrent CKD, plausibly because of the unique pathophysiology of heart failure in this population. The present review highlights recent advances in heart failure treatment as they apply to patients with CKD.

RECENT FINDINGS

Several recent publications have shown possible benefits of established heart failure therapies to improve clinical outcomes in patients with CKD; while others conclude neutral or even harmful effects of heart failure therapies in CKD patients. Novel heart failure therapies show promise to improve outcomes in the general population and should be evaluated in future studies to further elucidate the efficacy and safety of these novel therapies specifically in patients with CKD.

SUMMARY

Knowledge of heart failure treatment to improve clinical outcomes in the CKD population remains limited. Future studies should focus on patients with CKD to evaluate the generalizability of heart failure therapies to this patient population.

Vascular and inflammatory mineralocorticoid receptors in kidney disease

Mineralocorticoid receptor (MR) activation in the kidney can occur outside the aldosterone-sensitive distal nephron in sites including the endothelium, smooth muscle and inflammatory cells. MR activation in these cells has deleterious effects on kidney structure and function by promoting oxidative injury, endothelial dysfunction and stiffness, vascular remodelling and calcification, decreased relaxation and activation of T cells and pro-inflammatory macrophages. Here, we review the data showing the cellular consequences of MR activation in endothelial, smooth muscle and inflammatory cells and how this affects the kidney in pathological situations. The evidence demonstrating a benefit of pharmacological or genetic MR inhibition in various models of kidney disease is also discussed.

The non-steroidal mineralocorticoid receptor antagonist finerenone prevents cardiac fibrotic remodeling

Mineralocorticoid receptor (MR) overactivation promotes cardiac fibrosis. We studied the ability of the non-steroidal MR antagonist finerenone to prevent fibrotic remodeling. In neonatal rat cardiac fibroblasts, finerenone prevented aldosterone-induced nuclear MR translocation. Treatment with finerenone decreased the expression of connective tissue growth factor (CTGF) (74 ± 15% of control, p = 0.005) and prevented aldosterone-induced upregulation of CTGF and lysyl oxidase (LOX) completely. Finerenone attenuated the upregulation of transforming growth factor ß (TGF-ß), which was induced by the Rac1 GTPase activator l-buthionine sulfoximine. Transgenic mice with cardiac-specific overexpression of Rac1 (RacET) showed increased left ventricular (LV) end-diastolic (63.7 ± 8.0 vs. 93.8 ± 25.6 µl, p = 0.027) and end-systolic (28.0 ± 4.0 vs. 49.5 ± 16.7 µl, p = 0.014) volumes compared to wild-type FVBN control mice. Treatment of RacET mice with 100 ppm finerenone over 5 months prevented LV dilatation. Systolic and diastolic LV function did not differ between the three groups. RacET mice exhibited overactivation of MR and 11ß hydroxysteroid dehydrogenase type 2. Both effects were reduced by finerenone (reduction about 36%, p = 0.030, and 40%, p = 0.032, respectively). RacET mice demonstrated overexpression of TGF-ß, CTGF, LOX, osteopontin as well as collagen and myocardial fibrosis in the left ventricle. In contrast, expression of these parameters did not differ between finerenone-treated RacET and control mice. Finerenone prevented left atrial dilatation (6.4 ± 1.5 vs. 4.7 ± 1.4 mg, p = 0.004) and left atrial fibrosis (17.8 ± 3.1 vs. 12.8 ± 3.1%, p = 0.046) compared to vehicle-treated RacET mice. In summary, finerenone prevented from MR-mediated structural remodeling in cardiac fibroblasts and in RacET mice. These data demonstrate anti-fibrotic myocardial effects of finerenone.

Mineralocorticoid receptor antagonists and kidney diseases: pathophysiological basis

Chronic kidney disease (CKD) represents a global health concern, and its prevalence is increasing. The ultimate therapeutic option for CKD is kidney transplantation. However, the use of drugs that target specific pathways to delay or halt CKD progression, such as angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and sodium-glucose co-transporter-2 (SGLT-2) inhibitors is limited in clinical practice. Mineralocorticoid receptor activation in nonclassical tissues, such as the endothelium, smooth muscle cells, inflammatory cells, podocytes, and fibroblasts may have deleterious effects on kidney structure and function. Several preclinical studies have shown that mineralocorticoid receptor antagonists (MRAs) ameliorate or cure kidney injury and dysfunction in different models of kidney disease. In this review, we present the preclinical evidence showing a benefit of MRAs in acute kidney injury, the transition from acute kidney injury to CKD, hypertensive and diabetic nephropathy, glomerulonephritis, and kidney toxicity induced by calcineurin inhibitors. We also discuss the molecular mechanisms responsible for renoprotection related to MRAs that lead to reduced oxidative stress, inflammation, fibrosis, and hemodynamic alterations. The available clinical data support a benefit of MRA in reducing proteinuria in diabetic kidney disease and improving cardiovascular outcomes in CKD patients. Moreover, a benefit of MRAs in kidney transplantation has also been observed. The past and present clinical trials describing the effect of MRAs on kidney injury are presented, and the risk of hyperkalemia and use of other options, such as potassium binding agents or nonsteroidal MRAs, are also addressed. Altogether, the available preclinical and clinical data support a benefit of using MRAs in CKD, an approach that should be further explored in future clinical trials.

Mineralocorticoid Antagonism and Diabetic Kidney Disease

PURPOSE OF REVIEW

Type 2 diabetes (T2D) is associated with an increased risk of diabetic kidney disease (DKD), cardiovascular disease, and heart failure, in part through activation of the renin-angiotensin-aldosterone system (RAAS). Although recent cardiovascular outcome trials have identified newer therapeutic agents such as sodium-glucose cotransporter-2 (SGLT-2) inhibitors and glucagon-like peptide-1 (GLP-1)-receptor agonists that reduce the risk of these complications, patients still exhibit residual cardiorenal morbidity and mortality. Accordingly, the identification of pharmacological agents that attenuate micro- and macrovascular complications related to T2D is a major priority. Our aim was to review evidence for the role of novel mineralocorticoid receptor antagonists (MRAs) that are being developed as adjunctive therapies to reduce the risk of DKD and cardiovascular disease in the setting of T2D.

RECENT FINDINGS

Dual RAAS blockade with angiotensin-converting enzyme (ACE) inhibitor plus angiotensin receptor blockade (ARB) or ARB plus renin inhibition increases serious adverse events such as acute kidney injury and stroke. Due to the potential for these serious side effects, more recent interest has focused on newer, more selective non-steroidal MRAs such as finerenone as cardiorenal protective therapies. Finerenone reduces albuminuria in the setting of DKD in patients with T2D and has a lower risk of hyperkalemia compared to currently available MRAs. Novel MRAs such as finerenone have the potential to reduce the risk of DKD progression in patients with T2D. The impact of finerenone on hard, long-term cardiorenal endpoints is being examined in the FIGARO and FIDELIO trials in patients with DKD.