New ways of mitigating aldosterone in cardiorenal disease.

Steroidal mineralocorticoid receptor antagonists (MRAs) bind to the mineralocorticoid receptor and antagonize the effects of aldosterone, which contributes to the development and progression of cardio- and renovascular diseases. Guidelines recommend steroidal MRAs in patients with heart failure with reduced or mildly reduced ejection fraction, as they reduce morbidity and mortality. In heart failure with preserved ejection fraction, MRAs have not convincingly shown to improve prognosis. Steroidal MRAs delay the progression of chronic kidney disease, reduce proteinuria and lower blood pressure in resistant hypertension but can induce hyperkalaemia. Due to their limited selectivity to the mineralocorticoid receptor, steroidal MRAs can cause significant adverse effects, i.e. libido loss, erectile dysfunction, gynaecomastia, and amenorrhoea, leading to low rates of persistance. Against this background, new avenues for developing non-steroidal, selective (ns)MRAs and aldosterone-synthase inhibitors have been taken. Finerenone has been shown to delay the progression of diabetic nephropathy and lower the incidence of heart failure hospitalizations in patients with chronic kidney disease and diabetes compared with placebo. Finerenone has therefore been recommended by the 2023 European Society of Cardiology Guidelines for the management of diabetes in patients with type 2 diabetes and chronic kidney disease. Further randomized controlled trials assessing the safety and effectiveness of finerenone in patients with heart failure are currently ongoing. Esaxerenone provides antihypertensive effects and has been approved for the treatment of hypertension in Japan. Baxdrostat and lorundostat, novel selective aldosterone-synthase inhibitors, are currently under investigation. In phase II trials, baxdrostat and lorundostat were safe and effective in lowering blood pressure in resistant hypertension. In this review, we summarize and critically discuss the evidence for new drugs mitigating aldosterone in heart failure, hypertension, and chronic kidney disease.

The Global Burden of Resistant Hypertension and Potential Treatment Options.

Resistant hypertension (RH) is defined as systolic blood pressure (SBP) or diastolic blood pressure (DBP) that remains .140 mmHg or .90 mmHg, respectively, despite an appropriate lifestyle and the use of optimal or maximally tolerated doses of a three-drug combination, including a diuretic. This definition encompasses the category of controlled RH, defined as the presence of blood pressure (BP) effectively controlled by four or more antihypertensive agents, as well as refractory hypertension, referred to as uncontrolled BP despite five or more drugs of different classes, including a diuretic. To confirm RH presence, various causes of pseudo-resistant hypertension (such as improper BP measurement techniques and poor medication adherence) and secondary hypertension must be ruled out. Inadequate BP control should be confirmed by out-of-office BP measurement. RH affects about 5% of the hypertensive population and is associated with increased cardiovascular morbidity and mortality. Once RH presence is confirmed, patient evaluation includes identification of contributing factors such as lifestyle issues or interfering drugs/substances and assessment of hypertension-mediated organ damage. Management of RH comprises lifestyle interventions and optimisation of current medication therapy. Additional drugs should be introduced sequentially if BP remains uncontrolled and renal denervation can be considered as an additional treatment option. However, achieving optimal BP control remains challenging in this setting. This review aims to provide an overview of RH, including its epidemiology, pathophysiology, diagnostic work-up, as well as the latest therapeutic developments.

Systematic Review Article: New Drug Strategies for Treating Resistant Hypertension-the Importance of a Mechanistic, Personalized Approach.

Resistant hypertension (RHT) is characterized by persistently high blood pressure (BP) levels above the widely recommended therapeutic targets of less than 140/90 mmHg office BP, despite life-style measures and optimal medical therapies, including at least three antihypertensive drug classes at maximum tolerated dose (one should be a diuretic). This condition is strongly related to hypertension-mediated organ damage and, mostly, high risk of hospitalization due to hypertension emergencies or acute cardiovascular events. Hypertension guidelines proposed a triple combination therapy based on renin angiotensin system blocking agent, a thiazide or thiazide-like diuretic, and a dihydropyridinic calcium-channel blocker, to almost all patients with RHT, who should also receive either a beta-blocker or a mineralocorticoid receptor antagonist, or both, depending on concomitant conditions and contraindications. Several other drugs may be attempted, when elevated BP levels persist in these RHT patients, although their added efficacy in lowering BP levels on top of optimal medical therapy is uncertain. Also, renal denervation has demonstrated to be a valid therapeutic alternative in RHT patients. More recently, novel drug classes and molecules have been tested in phase 2 randomised controlled clinical trials in patients with RHT on top of optimal medical therapy with at least 2-3 antihypertensive drugs. These novel drugs, which are orally administered and are able to antagonize different pathophysiological pathways, are represented by non-steroid mineralocorticorticoid receptor antagonists, selective aldosterone synthase inhibitors, and dual endothelin receptor antagonists, all of which have proven to reduce seated office and 24-h ambulatory systolic/diastolic BP levels. The main findings of randomized clinical trials performed with these drugs  as well as their potential indications for the clinical management of RHT patients are summarised in this systematic review article.

Results from a Phase 1 Study Assessing the Pharmacokinetics of the Aldosterone Synthase Inhibitor Baxdrostat in Participants with Varying Degrees of Renal Function.

Baxdrostat is a selective small-molecule aldosterone synthase inhibitor in development for treatment of hypertension and chronic kidney disease. This phase 1, open-label, parallel-group study assessed the safety and pharmacokinetics (PK) of baxdrostat in participants with varying degrees of renal function. Participants were enrolled into control (estimated glomerular filtration rate [eGFR] ≥60 mL/min), moderate to severe renal impairment (eGFR 15-59 mL/min), or kidney failure (eGFR <15 mL/min) groups and received a single 10-mg baxdrostat dose followed by 7 days of inpatient PK blood and urine sampling. Safety was assessed by adverse events, clinical laboratory evaluations, vital signs, physical examinations, and electrocardiograms (ECGs). Thirty-2 participants completed the study. There were no deaths and only 1 mild drug-related adverse event (diarrhea). No clinically meaningful changes in laboratory values, vital signs, physical examinations, or ECGs occurred. Plasma concentration-time curves of baxdrostat were similar among all groups. Urine PK parameters were similar (approximately 12% excreted) in the moderate to severe renal impairment and control groups. Inadequate urine production in the kidney failure group resulted in minimal urinary baxdrostat excretion. Renal impairment had no significant impact on systemic exposure or clearance of baxdrostat, suggesting that dose adjustment due to PK differences in patients with kidney disease is unnecessary.

New trials in resistant hypertension: mixed blessing stories.

Resistant hypertension (RH) is linked to an increased risk of cardiovascular and renal complications. Treatment options include non-pharmacological interventions, such as lifestyle modifications, and the use of specific antihypertensive drug combinations, including diuretics. Renal denervation is another option for treatment-resistant hypertension. New compounds targeting different pathways involved in RH-including inhibitors of aminopeptidase A, endothelin antagonists and selective aldosterone synthase inhibitors-have been tested in clinical trials in this condition. The centrally acting drug firibastat, targeting the brain renin-angiotensin system, failed to demonstrate significant effectiveness in reducing blood pressure (BP) in patients with difficult-to-treat and RH in the Firibistat in Resistant Hypertension (FRESH) trial. Aprocitentan, a dual endothelin A and B receptor antagonist, showed a moderate but statistically significant decrease in BP in patients with RH in the Parallel-Group, Phase 3 Study with Aprocitentan in Subjects with Resistant Hypertension (PRECISION) trial. However, concerns remain about potential adverse events, such as fluid retention. The use of baxdrostat, a selective aldosterone synthase inhibitor, showed promising results in reducing BP in patients with treatment-resistant hypertension in the Baxdrostat in Resistant Hypertension (BrigHTN) trial. However, a subsequent trial, HALO, failed to meet its primary endpoint. The unexpected results may be influenced by factors such as patient adherence and white-coat hypertension. Despite the disappointing results from HALO, the potential benefits of inhibiting aldosterone synthesis remain to be fully understood. In conclusion, managing RH remains challenging, and new compounds like firibastat, aprocitentan and baxdrostat have shown varied effectiveness. Further research is needed to improve our understanding and treatment of this condition.

Evaluating phase II results of Baxdrostat, an aldosterone synthase inhibitor for hypertension.

INTRODUCTION: Hypertension, a global health concern, poses a significant risk for other cardiovascular diseases. While lifestyle modifications and interventions like the Dietary Approaches to Stop Hypertension (DASH) diet offer some respite, their maintenance can be challenging. Recently, the spotlight has turned toward the renin-angiotensin-aldosterone system, a crucial player in the pathophysiology of hypertension. Contrary to other drugs, Baxdrostat, an innovative aldosterone synthase inhibitor (ASI), targets aldosterone synthesis, mitigating negative systemic effects. AREAS COVERED: Baxdrostat showcases rapid absorption, high oral bioavailability, and significant selectivity for aldosterone synthase which presents a proactive approach to hypertension management by reducing aldosterone levels. Early trials have demonstrated its potential in lowering blood pressure in resistant hypertension cases. Current clinical trials are also exploring its application in primary aldosteronism and chronic kidney disease, with preliminary findings indicating its promise as a novel antihypertensive agent. This article encapsulates the current state of knowledge regarding Baxdrostat, encompassing its uses, ongoing clinical trials, and potential future clinical applications. EXPERT OPINION: Future research endeavors will play a pivotal role in unveiling the effectiveness and safety profile of this novel medication. Thus, positioning the baxdrostat as a valuable addition to the armamentarium of antihypertensive agents, especially for patients with complex, multifactorial hypertensive conditions.

Aldosterone Synthase Inhibitors and Dietary Interventions: A Combined Novel Approach for Prevention and Treatment of Cardiovascular Disease.

Systemic hypertension (HTN) is the hallmark of cardiovascular disease and the forerunner of heart failure. These associations have been established over decades of research on essential HTN. Advancements in the treatment of patients diagnosed with HTN, consisting of alpha- or beta-adrenergic receptor blockers, calcium channel blockers, angiotensin-converting enzyme inhibitors, thiazide, or aldosterone receptor blockers known as anti-mineralocorticoids, in the presence or absence of low sodium salt diets, often fail to control blood pressure adequately to prevent morbidity and mortality. Low sodium diets have had limited success in controlling HTN because low sodium intake is associated with renin-angiotensin-aldosterone system upregulation. Therefore, upregulating aldosterone secretion, sodium, and water retention which, in turn, moves the blood pressure back toward the range of HTN dictated by the baroreceptor reset value, as a compensatory mechanism, especially in resistant HTN. These impediments to blood pressure control in HTN may have been effectively circumvented by the advent of a new class of drugs known as aldosterone synthase inhibitors, represented by baxdrostat. The mechanism of action of baxdrostat as an aldosterone synthase inhibitor demonstrates the inextricable linkage between sodium and blood pressure regulation. Theoretically, combining a low sodium diet with the activity of this aldosterone synthesis inhibitor should alleviate the adverse effect of renin-angiotensin-aldosterone system upregulation. Aldosterone synthesis inhibition should also decrease the oxidative stress and endothelial dysfunction associated with HTN, causing more endothelial nitric oxide synthesis, release, and vasorelaxation. To the best of our knowledge, this is the first systematic review to summarize evidence-based articles relevant to the use of a novel drug (aldosterone synthase inhibitor) in the treatment of HTN and cardiovascular disease. Making the current database of relevant information on baxdrostat and other aldosterone synthase inhibitors readily available will, no doubt, aid physicians and other medical practitioners in their decision-making about employing aldosterone synthase inhibitors in the treatment of patients.