Increase in BNP in Response to Endothelin-Receptor Antagonist Atrasentan Is Associated With Incident Heart Failure

Selective endothelin A receptor antagonism in chronic kidney disease: improving clinical application

Endothelin-1 (ET-1) is a peptide that is involved in various chronic diseases including cardiovascular and kidney disease. ET-1 can bind to two receptors, endothelin A (ETA) and endothelin B (ETB), which are found in different organs and tissues. When ET-1 binds to the ETA receptor, it causes blood vessels to narrow, while binding of ET-1 to the ETB receptor causes blood vessels to widen. These receptors help regulate fluid and electrolyte balance in the kidneys, as well as the kidney's ability to filter various substances out of the body. Overactivation of ET-1 can occur in people with diabetes or obesity, which can damage the structure and function of the kidney.Studies in mice and humans with kidney disease have shown that blocking the ETA receptor improves kidney health. As a result, medicines that specifically block the ETA receptor, known as endothelin receptor antagonists (ERAs), are a promising option for treating these kidney diseases. The first ERA (sparsentan) is now available for use in patients with immunoglobulin A (IgA) nephropathy, a specific type of kidney disease. It should be noted that ERAs can cause side effects. Fluid retention, which can increase the risk of heart failure, is a side effect that is particularly observed in patients with type 2 diabetes and severe kidney disease. This side effect is less often observed in patients with IgA nephropathy or patients without diabetes.Treatment strategies to optimize safe and effective use of ETA blockers are being developed. Overall, these insights offer hope for better care of patients with kidney disease.

ABSTRACT

Endothelin-1 (ET-1) is a 21-amino acid peptide involved in numerous cardiovascular and renal processes. ET-1 can bind to endothelin receptor A (ETA) and endothelin receptor B (ETB), which are found in various organs and tissues. In general, binding of ET-1 to the ETA receptor causes vasoconstriction, whereas activation of the ETB receptor leads to vasodilation. In the kidney, endothelin receptors regulate fluid and electrolyte balance, regional blood flow and glomerular filtration rate. In pathological conditions, ET-1 promotes kidney injury through adverse effects on the endothelial glycocalyx, podocytes and mesangial cells, and stimulating inflammation and fibrosis in the tubules. In experimental and clinical studies, inhibition of the ETA receptor has been shown beneficial in a variety of kidney diseases. These include diabetic kidney disease, immunoglobulin A nephropathy, focal segmental glomerulosclerosis and Alport syndrome. Accordingly, selective ETA endothelin receptor antagonists (ERA) may prove a viable therapeutic option in these diseases. However, clinical application is challenged by the occurrence of fluid retention which can lead to heart failure, in particular in patients with severe CKD. Concomitant use of sodium-glucose cotransporter 2 inhibitors (SGLT2i) may mitigate these adverse effects through their diuretic actions. The development of highly selective ETA antagonists, such as atrasentan and zibotentan, and the opportunities of combining these with SGLT2i, holds promise to optimize efficacy and safety of ERAs in clinical practice.

Natriuretic Peptides, Kidney Function, and Clinical Outcomes in Heart Failure With Preserved Ejection Fraction

BACKGROUND

N-terminal pro-B-type natriuretic peptides (NT-proBNPs) are guideline-recommended biomarkers for risk stratification in patients with heart failure. However, NT-proBNP levels are often elevated in chronic kidney disease, introducing uncertainty about their prognostic relevance in persons across a broad range of estimated glomerular filtration rate (eGFR).

OBJECTIVES

The aim of this study was to assess the association of NT-proBNP with cardiovascular and mortality outcomes in patients with heart failure and mildly reduced or preserved ejection fraction, stratified by baseline kidney function.

METHODS

A pooled analysis was conducted of participants with NT-proBNP and eGFR measured at baseline in the I-PRESERVE (Irbesartan in Heart Failure and Preserved Ejection Fraction), TOPCAT (Americas region) (Aldosterone Antagonist Therapy for Adults With Heart Failure and Preserved Systolic Function), PARAGON (Prospective Comparison of ARNI with ARB Global Outcomes in HF With Preserved Ejection Fraction), and DELIVER (Dapagliflozin Evaluation to Improve the LIVEs of Patients With PReserved Ejection Fraction Heart Failure) trials. The relationship between NT-proBNP and eGFR was assessed using piecewise linear regression. Using multivariable Cox and Poisson regression models, the association of NT-proBNP with outcomes across a range of eGFR was evaluated. The primary outcome was hospitalization for heart failure or cardiovascular death.

RESULTS

Among 14,831 participants (mean age: 72.1 years; 50.3% female; mean eGFR: 63.3 mL/min/1.73 m2, and median NT-proBNP: 840 pg/mL) followed up for a median 33.5 months, there were 3,092 primary outcomes. NT-proBNP levels increased by 9%, 8%, and 23% per 10 mL/min/1.73 m2 lower eGFR in patients with baseline eGFR ≥60, 45-<60, and <45 mL/min/1.73 m2, respectively (P for nonlinearity < 0.001). Each doubling in NT-proBNP was associated with a 37% relative increase in the primary outcome (HR: 1.37; 95% CI: 1.34-1.41), consistent across different eGFR categories (P for interaction = 0.42). For the same incidence of the primary outcome, NT-proBNP levels were approximately 2.5- to 3.5-fold lower in patients with eGFR <45 mL/min/1.73 m2, compared with patients with eGFR ≥60 mL/min/1.73 m2. Similar patterns were observed across all outcomes studied, including cardiovascular and noncardiovascular death.

CONCLUSIONS

The same NT-proBNP concentration predicts a substantially higher absolute risk of adverse outcomes for people with heart failure and reduced kidney function, compared with those with preserved kidney function. These data call into question proposals for higher NT-proBNP references ranges in people with CKD, and suggest that reduced kidney function per se should not be a reason to disregard higher NT-proBNP levels.

The Selective Endothelin Receptor Antagonist SC0062 in IgA Nephropathy: A Randomized Double-Blind Placebo-Controlled Clinical Trial

Key Points

Background

Endothelin receptor type A activation contributes to kidney injury in patients with IgA nephropathy. SC0062 is a novel selective endothelin receptor type A antagonist. We report the results of a phase 2 dose-finding trial to characterize the efficacy and safety of SC0062 in patients with IgA nephropathy.

Methods

We conducted a randomized, placebo-controlled, double-blind, clinical trial in adults with biopsy-proven IgA nephropathy and eGFR ≥30 ml/min per 1.73 m2 with urine protein-creatinine ratio (UPCR) ≥0.75 g/g or proteinuria ≥1 g/24 hour despite using maximum tolerated doses of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. Patients were randomized 1:1:1:1 to 24-week treatment with SC0062 5, 10, and 20 mg or matching placebo once daily. The primary efficacy outcome was percent change from baseline in UPCR in 24-hour urine samples after 12 weeks of treatment. Secondary end points included changes in eGFR. Safety outcomes including treatment-emergent adverse events and serious adverse events were recorded.

Results

Overall, 131 patients (mean age 42 years [SD 11]; mean eGFR 72 ml/min per 1.73 m2 [SD 24] and median 24-hour UPCR 1.2 g/g [25th–75th percentile, 0.9–1.5 g/g]) were randomized to placebo (n=34) or SC0062 5 mg (n=33), 10 mg (n=32), or 20 mg (n=32). All SC0062 doses reduced UPCR versus placebo throughout treatment. At week 12, placebo-corrected geometric mean changes (95% confidence interval) from baseline in UPCR with SC0062 5, 10, and 20 mg were−27.6% (−43.0 to −8.2), −20.5% (−37.4 to 1.0), and −38.1% (−51.4 to −21.0), respectively, and at week 24 they were−22.4% (−42.2 to 4.3), −30.9% (−48.6 to −7.0), and −51.6% (−64.2 to −34.6), respectively. No differences in eGFR were observed among treatment groups. The proportion of participants with treatment-emergent adverse events or serious adverse events was balanced among treatment groups. Peripheral edema was reported by two (6%), one (3%), one (3%) participants in the 5, 10, and 20 mg SC0062-treated groups, respectively, compared with five (15%) in the placebo group.

Conclusions

In patients with IgA nephropathy, SC0062 reduced proteinuria and did not increase risk of peripheral edema.

Clinical Trial registry name and registration number:

A Study to Evaluate the Efficacy and Safety of SC0062 in the Treatment of CKD, NCT05687890.

Effects of Zibotentan Alone and in Combination with Dapagliflozin on Fluid Retention in Patients with CKD

Key Points

Increasing doses of the endothelin receptor antagonist zibotentan and lower eGFR were associated with a higher risk of fluid retention. The higher risk of fluid retention could be attenuated by the combination of zibotentan with the sodium-glucose cotransporter 2 inhibitor dapagliflozin.

Background

Endothelin receptor antagonists (ERAs) reduce albuminuria but are limited by fluid retention risk, particularly in patients with CKD. Combining ERAs with sodium-glucose cotransporter 2 (SGLT2) inhibitors, which have diuretic effects, offers a promising strategy to mitigate fluid retention. In this post hoc analysis of the Zibotentan and Dapagliflozin for the Treatment of CKD (ZENITH-CKD) trial, we assessed fluid dynamics in patients with CKD treated with the ERA zibotentan alone and in combination with the SGLT2 inhibitor dapagliflozin.

Methods

In the ZENITH-CKD trial, 508 patients with CKD (eGFR ≥20 ml/min per 1.73 m2 and a urinary albumin-creatinine ratio of 150–5000 mg/g) were randomized to treatment with placebo, dapagliflozin 10 mg plus placebo, zibotentan (0.25, 1.5, or 5 mg) plus dapagliflozin 10 mg, and zibotentan 5 mg plus placebo. We evaluated correlations between changes in fluid retention markers and bioimpedance-measured extracellular fluid in response to zibotentan treatment. We used Cox proportional hazards regression to assess the association between zibotentan/dapagliflozin treatment, baseline characteristics, and fluid retention and the relationship between zibotentan plasma exposure and fluid retention.

Results

After 3 weeks of treatment with zibotentan 0.25, 1.5, or 5 mg plus dapagliflozin 10 mg, changes in body weight (β =0.36 [95% confidence interval (CI), 0.26 to 0.45]) per kg, B-type natriuretic peptide (β =0.38 [95% CI, 0.22 to 0.54]) per doubling, and hemoglobin (β =−0.29 [95% CI, −0.48 to −0.10]) per g/dl were independently associated with changes in extracellular fluid. Higher doses of zibotentan were associated with significantly higher risk of fluid retention compared with dapagliflozin alone (zibotentan 5 mg hazard ratio (HR) 8.50 [95% CI, 3.40 to 21.30]). The HR attenuated when zibotentan was combined with dapagliflozin (zibotentan/dapagliflozin 5/10 mg HR 3.09 [95% CI, 1.08 to 8.80], zibotentan/dapagliflozin 1.5/10 mg 2.70 [95% CI, 1.44 to 5.07], and zibotentan/dapagliflozin 0.25/10 mg HR 1.21 [95% CI, 0.50 to 2.91]). The risk of fluid retention was higher with higher zibotentan exposure and lower eGFR.

Conclusions

High doses of zibotentan were associated with a higher risk of fluid retention, which was attenuated with lower doses and the addition of dapagliflozin.

Clinical Trial registry name and registration number:

ZENITH-CKD Trial, NCT04724837 .

Vericiguat on C-reactive Protein Level and Prognosis in Patients with Hypertensive Heart Failure

INTRODUCTION

Hypertensive heart failure (HHF) has a high incidence and poor prognosis.

AIM

This article evaluated the efficacy and safety of Vericiguat in HHF and analyzed the relationship between C-reactive protein (CRP) levels and patient prognosis.

METHODS

110 HHF patients were divided into Placebo and Vericiguat groups. Cardiac function was assessed by echocardiography and 6-minute walk test (6MWT). Blood samples were collected to detect the levels of N-terminal pro-brain natriuretic peptide (NT-proBNP), cardiac troponin I (cTnI), endothelin (ET-1), nitric oxide (NO), and CRP.

RESULTS

Left ventricular end systolic diameter (LVESD) and left ventricular end diastolic dimension (LVEDD) were reduced, the left ventricular ejection fraction (LVEF) and 6MWT were increased, and the serum levels of NT-proBNP, cTnI, ET-1, NO, and CRP were decreased in Vericiguat group as against Placebo group; The total effective rate was 76.4% in Placebo group and 92.7% in Vericiguat group (P < 0.05). The adverse reaction rate was 10.9% and 9.1% (P > 0.05). The proportion of persons with poor prognosis and no improvement of cardiac function in patients with highly expressed CRP before treatment was higher as against patients with low expression of CRP (P < 0.05). Highly expressed CRP is an independent risk factor for poor prognosis.

CONCLUSION

Vericiguat is safe and effective in improving cardiac function in HHF patients.

Endothelin receptor antagonists in diabetic and non-diabetic chronic kidney disease

Chronic kidney disease (CKD) is one of the major causes of morbidity and mortality, affecting >800 million persons globally. While we still lack efficient, targeted therapies addressing the major underlying pathophysiologic processes in CKD, findings of several recent trials have brought about a shifting landscape of promising therapies. The endothelin system has been implicated in the pathophysiology of CKD and endothelin receptor antagonists are one class of drugs for which we have increasing evidence of efficacy in these patients. In this review we summarize the most recent findings on the safety and efficacy of endothelin receptor antagonists in diabetic and non-diabetic CKD, future directions of research and upcoming treatments.

Efficacy and safety of zibotentan and dapagliflozin in patients with chronic kidney disease: study design and baseline characteristics of the ZENITH-CKD trial

BACKGROUND

Sodium-glucose co-transporter 2 inhibitors (SGLT2is) are part of the standard of care for patients with chronic kidney disease (CKD), both with and without type 2 diabetes. Endothelin A (ETA) receptor antagonists have also been shown to slow progression of CKD. Differing mechanisms of action of SGLT2 and ETA receptor antagonists may enhance efficacy. We outline a study to evaluate the effect of combination zibotentan/dapagliflozin versus dapagliflozin alone on albuminuria and estimated glomerular filtration rate (eGFR).

METHODS

We are conducting a double-blind, active-controlled, Phase 2b study to evaluate the efficacy and safety of ETA receptor antagonist zibotentan and SGLT2i dapagliflozin in a planned 415 adults with CKD (Zibotentan and Dapagliflozin for the Treatment of CKD; ZENITH-CKD). Participants are being randomized (1:2:2) to zibotentan 0.25 mg/dapagliflozin 10 mg once daily (QD), zibotentan 1.5 mg/dapagliflozin 10 mg QD and dapagliflozin 10 mg QD alone, for 12 weeks followed by a 2-week off-treatment wash-out period. The primary endpoint is the change in log-transformed urinary albumin-to-creatinine ratio (UACR) from baseline to Week 12. Other outcomes include change in blood pressure from baseline to Week 12 and change in eGFR the study. The incidence of adverse events will be monitored. Study protocol-defined events of special interest include changes in fluid-related measures (weight gain or B-type natriuretic peptide).

RESULTS

A total of 447 patients were randomized and received treatment in placebo/dapagliflozin (n = 177), zibotentan 0.25 mg/dapagliflozin (n = 91) and zibotentan 1.5 mg/dapagliflozin (n =  179). The mean age was 62.8 years, 30.9% were female and 68.2% were white. At baseline, the mean eGFR of the enrolled population was 46.7 mL/min/1.73 m2 and the geometric mean UACR was 538.3 mg/g.

CONCLUSION

This study evaluates the UACR-lowering efficacy and safety of zibotentan with dapagliflozin as a potential new treatment for CKD. The study will provide information about an effective and safe zibotentan dose to be further investigated in a Phase 3 clinical outcome trial.

CLINICAL TRIAL REGISTRATION NUMBER

NCT04724837.

Targeting the Endothelin A Receptor in IgA Nephropathy

Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis worldwide and carries a substantial risk of kidney failure. New agency-approved therapies, either specifically for IgAN or for chronic kidney disease (CKD) in general, hold out hope for mitigating renal deterioration in patients with IgAN. The latest addition to this therapeutic armamentarium targets the endothelin-A receptor (ETAR). Activation of ETAR on multiple renal cell types elicits a host of pathophysiological effects, including vasoconstriction, cell proliferation, inflammation, apoptosis, and fibrosis. Blockade of ETAR is renoprotective in experimental models of IgAN and reduces proteinuria in patients with IgAN. This review discusses the evidence supporting the use of ETAR blockade in IgAN as well as addressing the potential role for this class of agents among the current and emerging therapies for treating this disorder.

The sodium glucose co-transporter 2 inhibitor dapagliflozin ameliorates the fluid-retaining effect of the endothelin A receptor antagonist zibotentan

BACKGROUND

Endothelin A receptor antagonists (ETARA) slow chronic kidney disease (CKD) progression but their use is limited due to fluid retention and associated clinical risks. Sodium-glucose co-transporter 2 inhibitors (SGLT2i) cause osmotic diuresis and improve clinical outcomes in CKD and heart failure. We hypothesized that co-administration of the SGLT2i dapagliflozin with the ETARA zibotentan would mitigate the fluid retention risk using hematocrit (Hct) and bodyweight as proxies for fluid retention.

METHODS

Experiments were performed in 4% salt fed WKY rats. First, we determined the effect of zibotentan (30, 100 or 300 mg/kg/day) on Hct and bodyweight. Second, we assessed the effect of zibotentan (30 or 100 mg/kg/day) alone or in combination with dapagliflozin (3 mg/kg/day) on Hct and bodyweight.

RESULTS

Hct at Day 7 was lower in zibotentan versus vehicle groups [zibotentan 30 mg/kg/day, 43% (standard error 1); 100 mg/kg/day, 42% (1); and 300 mg/kg/day, 42% (1); vs vehicle, 46% (1); P < .05], while bodyweight was numerically higher in all zibotentan groups compared with vehicle. Combining zibotentan with dapagliflozin for 7 days prevented the change in Hct [zibotentan 100 mg/kg/day and dapagliflozin, 45% (1); vs vehicle 46% (1); P = .44] and prevented the zibotentan-driven increase in bodyweight (zibotentan 100 mg/kg/day + dapagliflozin 3 mg/kg/day = -3.65 g baseline corrected bodyweight change; P = .15).

CONCLUSIONS

Combining ETARA with SGLT2i prevents ETARA-induced fluid retention, supporting clinical studies to assess the efficacy and safety of combining zibotentan and dapagliflozin in individuals with CKD.

The Correlation Between Cardiac Oxidative Stress and Inflammatory Cytokine Response Following Myocardial Infarction

Our study was conducted to investigate the potential correlation between cardiac oxidative stress and inflammatory cytokine response following myocardial infarction. A total of 120 patients harboring acute myocardial infarction who underwent percutaneous coronary intervention (PCI) at our hospital were included. Their general clinical data were analyzed, and comparisons were made regarding the levels of inflammatory factors, oxidative stress markers, heart pump function, and cardiac function. The correlation between cardiac oxidative stress and inflammatory cytokine response was assessed using Pearson's linear correlation. Following treatment, significant reductions were seen in the serum levels of cortisol, thyroid-stimulating hormone (TSH), B-type natriuretic peptide (BNP), C-reactive protein (CRP), signal transducer and activator of transcription 3 (STAT3), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor (TNF), and catalase (CAT) compared to pre-treatment levels. Conversely, the levels of growth hormone (GH), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), cardiac output (CO), and cardiac index (CI) were significantly elevated. Serum cortisol (r = 0.481, P = .001), BNP (r = 0.437, P = .001), CRP (r = 0.542, P = .001), STAT3 (r = 0.835, P = .001), TSH (P = .001), IL-8 (r = 0.867, P = .001), TNF-α (r = 0.439, P = .001), and cardiac oxidative stress demonstrated significantly positive correlations (P < .05). Additionally, a significant negative correlation was found between GH (r = -0.654, P = .001) and immune balance (P < .05). This study evaluated the severity of myocardial infarction using indicators such as CO and CI. This study found a significant correlation between cardiac oxidative stress and inflammatory cytokines after myocardial infarction, suggesting their potential as predictors of myocardial infarction severity.