Managing resistant hypertension: focus on mineralocorticoid-receptor antagonists

Advances on the Experimental Research in Resistant Hypertension

PURPOSE OF REVIEW

Resistant Hypertension (RH) poses a significant public health challenge, contributing to increased mortality, cardiovascular events and organ damage. Both clinical and experimental research are striving for higher standards in a translational manner to integrate new findings and confirm hypotheses. Considering that many are the aspects of RH that are still under investigation, this review aims to shed light on the advances made in experimental research concerning RH. It seeks to underscore the pivotal role of experimental studies in shaping clinical practices and also explore future perspectives.

RECENT FINDINGS

It is important to emphasize the significance of experimental models, primarily for advancing our understanding: experimental models have greatly contributed to our comprehension of the underlying mechanisms in RH, including factors like sympathetic activation, endothelial dysfunction and structural vessel abnormalities. Secondly, for assessing treatment approaches: animal models have also played a crucial role in evaluating the potential effectiveness of diverse treatment approaches for RH. These encompass both pharmacological options, involving combinations of established drugs or novel pharmaceuticals, and non-pharmacological alternatives, which include surgical procedures like renal denervation, medical devices like baroreceptor stimulators, and lifestyle modifications. The most lacking component in translational research is the fact that there is no well-established animal model that perfectly replicates RH. Consequently, alternative strategies, including the combination of models, must be considered. What remains clear is that the development of animal models closely mimicking RH holds the promise of providing valuable insights into the essential mechanisms and responses necessary to combat or slow the global progression of RH.

The Increasing Problem of Resistant Hypertension: We'll Manage till Help Comes!

Arterial hypertension remains the major cardiovascular risk worldwide. It is estimated that under 50 years of age one in every three adults is hypertensive while beyond the age of 50 the prevalence is almost 50% globally. The latest World Health Organization (WHO) Global Report on Hypertension indicated that the global number of hypertensive patients almost doubled in the last three decades, with related increasing deaths, disability, and costs annually. Because of this global increase, early diagnosis and timely treatment is of great importance. However, based on the WHO Global Report, it is estimated that up to 46% of individuals were never diagnosed. Of those diagnosed, less than 50% were on treatment, with nearly half among these at target according to the current guidelines. It is also important to note that an increasing number of hypertensive patients, despite the use of three or more drugs, still do not achieve a blood pressure normalization, thus defining the clinical scenario of resistant hypertension (RH). This condition is associated to a higher risk of hypertension-mediated organ damage and hospitalization due to acute cardiovascular events. Current guidelines recommend a triple combination therapy (renin angiotensin system blocking agent + a thiazide or thiazide-like diuretic + a dihydropyridinic calcium-channel blocker) to all patients with RH. Beta-blockers and mineralocorticoid receptor antagonists, alone or in combination, should be also considered based on concomitant conditions and potential contraindications. Finally, the renal denervation is also proposed in patients with preserved kidney function that remain hypertensive despite the use of maximum tolerated medical treatment. However, the failure of this procedure in the long term and the contraindication in patients with kidney failure is a strong call for a new therapeutic approach. In the present review, we will discuss the pharmacological novelties to come for the management of hypertension and RH in the next future.

Safety and efficacy of bilateral superselective adrenal arterial embolization for treatment of idiopathic hyperaldosteronism: a prospective single-center study

OBJECTIVE

This study aimed to assess the efficacy and safety of bilateral superselective adrenal arterial embolization (SAAE) in patients with bilateral idiopathic hyperaldosteronism (IHA), a subtype of PA.

METHODS

Ninety-eight patients with bilateral IHA underwent bilateral SAAE between August 2022 and August 2023. Sixty-eight patients were followed up for up to 12 months. The study outcomes were evaluated using the criteria provided by the Primary Aldosteronism Surgical Outcome (PASO) guidelines.

RESULTS

The mean reductions in systolic and diastolic blood pressure were 27.4 ± 21.3 mmHg and 23.1 ± 17.4 mmHg, respectively (p < 0.001). The rates of clinical success and biochemical success after adrenal artery ablation were 63.2% (43/68) and 39.7% (27/68), respectively. Overall, there were significant reductions in daily defined doses (DDD), aldosterone/renin ratio (ARR), and plasma aldosterone levels (p < 0.001). Plasma renin levels increased by a mean value of 10.4 ± 39.0 pg/mL (p = 0.049), and potassium levels increased by 0.40 ± 0.63 mmol/L (p < 0.001). No significant adverse events were reported during SAAE or the follow-up period of up to one year. Additionally, no abnormalities were detected by adrenal 68Ga-Pentixafor PET/CT scans before or after SAAE.

CONCLUSION

Bilateral SAAE appears to lead to sustained improvements in blood pressure and biochemical parameters in patients with bilateral PA, with minimal adverse effects. This suggests that bilateral SAAE could serve as an effective alternative approach for treating bilateral IHA, potentially curing this condition.

Efficacy and safety of esaxerenone (CS-3150) in primary hypertension: a meta-analysis

This study aimed to assess the efficacy and safety of esaxerenone (CS-3150) in treating primary hypertension. PubMed (Medline), Cochrane Central Register of Controlled Trials (CENTRAL), and Embase databases were searched for articles published until April 18, 2023. The outcomes included were diastolic blood pressure (DBP), systolic blood pressure (SBP), 24 h DBP, 24 h SBP, and adverse events. The meta-analysis was conducted using RevMan 5.3. This study included three trials. CS-3150 5 mg had a greater effect on lowering the SBP, DBP, 24 h SBP, and 24 h DBP than either CS-3150 2.5 mg or eplerenone 50 mg. In contrast, CS-3150 2.5 mg and eplerenone 50 mg showed no significant difference in lowering DBP, SBP, 24 h DBP, and 24 h SBP. Moreover, adverse events occurred at comparable rates in the three groups. CS-3150 (especially CS-3150 5 mg) is an effective and safe treatment for primary hypertension; which can reduce blood pressure and alleviate hypertensive symptoms.

Effect of Sequential Nephron Blockade versus Dual Renin-Angiotensin System Blockade Plus Bisoprolol in the Treatment of Resistant Hypertension, a Randomized Controlled Trial (Resistant Hypertension on Treatment - ResHypOT)

Introduction

Hypertension is the most important modifiable risk factor for cardiovascular disease and a leading public health concern.

Objectives

The primary aim was to compare sequential nephron blockade (SNB) versus dual renin-angiotensin system blockade (DRASB) plus bisoprolol in patients with resistant hypertension to observe reductions in systolic and diastolic blood pressure (SBP and DBP) levels after 20 weeks of treatment.

Material and Methods

This trial was an open-label, prospective, randomized, parallel-group, clinical study with optional drug up-titration. Participants were evaluated during five visits at 28-day intervals.

Results

The mean age was 55.5 years in the SNB and 58.4 years in the DRASB + bisoprolol group (p=NS). Significant office BP reductions were observed in both groups. SNB group, SBP decreased from 174.5±21.0 to 127.0±14.74 mmHg (p<0.0001), and DBP decreased from 105.3±15.5 to 78.11±9.28 mmHg (p<0.0001). DRASB group, SBP decreased from 178.4±21.08 to 134.4 ± 23.25 mmHg (p<0.0001) and DBP decreased from 102.7±11.07 to 77.33±13.75 mmHg (p<0.0001). Ambulatory blood pressure monitoring (ABPM) showed also significant SBP and DBP reductions in both groups (p<0.0001).

Conclusion

In patients with RHTN adherent to treatment, SNB and DRASB plus bisoprolol showed excellent therapeutic efficacy, although SNB was associated with earlier SBP reduction.

Treatment-resistant hypertension

Treatment-resistant hypertension is one of the most significant causes of poor blood pressure regulation. Patients with resistant hypertension are at a higher risk of developing comorbidities compared to the general hypertensive population. As a result, these patients have an increased incidence of disability and premature death, as well as increased treatment costs. Due to the above-mentioned, in the last decade, there has been an increase in researchers' interest in elucidating the pathogenesis, diagnosis, and treatment of resistant hypertension. However, recent data indicate that 20% of female and 24% of male patients with arterial hypertension still have uncontrolled blood pressure, despite maximum doses of three antihypertensive drugs (including a diuretic) and appropriate lifestyle measures. New treatment modalities (i.e. devicebased interventions - catheter-based renal denervation and baroreceptor stimulation) offer hope for achieving adequate blood pressure regulation in these patients. In this paper, we have summarized previous knowledge about the mechanisms underlying the pathogenesis of resistant hypertension, as well as optimal diagnostic methods to differentiate true from pseudo-resistant hypertension. We have also given an overview of the current therapeutic approach, including optimal medical therapy and new treatment modalities (i.e. device-based interventions) and their role in the treatment of resistant hypertension.

Effect of renal denervation on catecholamines and the renin-angiotensin-aldosterone system

Introduction:

The effect of renal sympathetic denervation (RDN) on neurohormonal responses is largely unknown. We aimed to assess the effect of RDN on the renin–angiotensin–aldosterone system (RAAS) and endogenous catecholamines.

Methods:

A total of 60 patients with hypertension underwent RDN and remained on a stable antihypertensive drug regimen. Samples for plasma aldosterone, plasma renin and urine (nor)metanephrine were collected at baseline and at 6 months post procedure. Ambulatory blood pressure (BP) recordings were obtained at baseline and at 6 months post procedure.

Results:

Mean age was 64±9 years, and 30/60 patients were male. At 6 months, average daytime systolic and diastolic ambulatory BP decreased by 10 and 6 mmHg, respectively (p<0.001). No significant change was observed in plasma aldosterone (median=248.0 pmol/L (interquartile range (IQR) 113.3–369.5 pmol/L) vs. median=233.0 pmol/L (IQR 110.3–360.8 pmol/L); p=0.66); renin (median=19.5 µIU/mL (IQR 6.8–119.5 µIU/mL) vs. median=14.3 µIU/mL (IQR 7.2–58.0 µIU/mL); p=0.32), urine metanephrine (median=0.46 µmol/L (IQR 0.24–0.77 µmol/L) vs. median=0.46 µmol/L (IQR 0.22–0.88 µmol/L); p=0.75) and normetanephrine (median=1.41 µmol/L (IQR 0.93–2.00 µmol/L vs. median =1.56 (IQR 0.74–2.50 µmol/L); p=0.58) between baseline and 6 months, respectively. No correlation was found between the decrease in mean systolic daytime BP and changes in RAAS hormones or endogenous catecholamines.

Conclusion:

Despite significant reductions in ambulatory BP, RDN did not result in a significant change in endogenous catecholamines or in RAAS hormones at 6 months.

Mineralocorticoid Receptor Antagonists Eplerenone and Spironolactone Modify Adrenal Cortex Morphology and Physiology

Mineralocorticoid receptor antagonists (MRAs) are a class of anti-hypertensive drugs that act by blocking aldosterone action. The aim of this study was to evaluate whether the MRAs spironolactone and eplerenone influence adrenal cortical physiology and morphology. Spontaneous hypertensive rats (SHR, n = 18) and normotensive rats (WKY, n = 18) were randomly exposed to a daily dose of spironolactone (n = 6), eplerenone (n = 6), or no drug (n = 6) over 28 days. After that, aldosterone, corticosterone, and 11-deoxycorticosterone plasma concentrations were quantified. Adrenal glands were subjected to morphological analysis to assess lipid droplets content, capsular width, cell proliferation, and steroidogenic proteins expression. The adrenal cortex in untreated SHR showed higher lipid droplet content as than in WKY. In SHR, MRA treatment was associated with higher circulating aldosterone levels and Ki-67 expression in aldosterone-secreting cells. In WKY, the only difference observed after MRA spironolactone treatment was a narrower capsule. There was no difference in abundance of steroidogenic enzyme between groups. In conclusion, MRAs modify adrenal gland function and morphology in SHR. The effects observed within the adrenal glomerulosa with aldosterone-secreting cell proliferation and higher circulating aldosterone levels suggests that MRA treatment provokes activation of the renin angiotensin system. The prognostic value of hyperaldosteronism secondary to MRAs blockade requires further investigation.

Identification of key candidate genes and pathways revealing the protective effect of liraglutide on diabetic cardiac muscle by integrated bioinformatics analysis

Background

Diabetes mellitus is becoming a significant health problem with the International Diabetes Federation (IDF) expecting a startling 642 million diabetes patients by 2040. Liraglutide, a glucagon-like peptide-1 (GLP-1) analog, is reported to protect against diabetic cardiomyopathy by binding to the receptor, GLP-1R. However, the underlying mechanism has yet to be clarified. This study aimed to investigate the underlying mechanisms and the effects of liraglutide on diabetic patient's cardiac muscles.

Methods

GSE102194 genetic expression profiles were extracted from the Gene Expression Omnibus (GEO) database. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses were carried out. Next, Cytoscape software was used to construct the protein-protein interaction (PPI) network of the differentially expressed genes (DEGs). DEGs were mapped onto a protein-protein interaction (PPI) network that comprised 249 nodes and 776 edges.

Results

A total of 520 DEGs were discovered, including 159 down-regulated genes and 361 up-regulated genes. DEGs that were upregulated were notably enriched in biological processes (BP) such as muscle system process, muscle system process, muscle structure development and anatomical structure morphogenesis while DEGs that were downregulated were rich in detection of chemical stimulus and neurological system process. KEGG pathway analysis showed the up-regulated DEGs were enriched in adrenergic signaling for cardiomyocytes, dopaminergic synapse, and circadian entrainment, while the down-regulated DEGs were enriched for factory transduction in 249 of the 520 tested samples. The modular analysis identified 4 modules that participated in some pathways associated with cardiac muscle contraction, hypertrophic cardiomyopathy (HCM), and MAPK signaling pathway.

Conclusions

Our data showed that Glp-1 could decrease the protein expression of p38, JNK, ERK1/2, and MARS proteins induced by high glucose (22 mM, 72 h). This study highlights the potential physiological processes that take place in diabetic cardiac muscles exposed to liraglutide. Our findings elucidated the regulatory network in diabetic cardiomyopathy and might provide a novel diagnostic and therapeutic target for diabetic cardiomyopathy.

The endothelial mineralocorticoid receptor: Contributions to sex differences in cardiovascular disease

Cardiovascular disease remains the leading cause of death for both men and women. The observation that premenopausal women are protected from cardiovascular disease relative to age-matched men, and that this protection is lost with menopause, has led to extensive study of the role of sex steroid hormones in the pathogenesis of cardiovascular disease. However, the molecular basis for sex differences in cardiovascular disease is still not fully understood, limiting the ability to tailor therapies to male and female patients. Therefore, there is a growing need to investigate molecular pathways outside of traditional sex hormone signaling to fully understand sex differences in cardiovascular disease. Emerging evidence points to the mineralocorticoid receptor (MR), a steroid hormone receptor activated by the adrenal hormone aldosterone, as one such mediator of cardiovascular disease risk, potentially serving as a sex-dependent link between cardiovascular risk factors and disease. Enhanced activation of the MR by aldosterone is associated with increased risk of cardiovascular disease. Emerging evidence implicates the MR specifically within the endothelial cells lining the blood vessels in mediating some of the sex differences observed in cardiovascular pathology. This review summarizes the available clinical and preclinical literature concerning the role of the MR in the pathophysiology of endothelial dysfunction, hypertension, atherosclerosis, and heart failure, with a special emphasis on sex differences in the role of endothelial-specific MR in these pathologies. The available data regarding the molecular mechanisms by which endothelial-specific MR may contribute to sex differences in cardiovascular disease is also summarized. A paradigm emerges from synthesis of the literature in which endothelial-specific MR regulates vascular function in a sex-dependent manner in response to cardiovascular risk factors to contribute to disease. Limitations in this field include the relative paucity of women in clinical trials and, until recently, the nearly exclusive use of male animals in preclinical investigations. Enhanced understanding of the sex-specific roles of endothelial MR could lead to novel mechanistic insights underlying sex differences in cardiovascular disease incidence and outcomes and could identify additional therapeutic targets to effectively treat cardiovascular disease in men and women.

New Molecules for Treating Resistant Hypertension: a Clinical Perspective

PURPOSE OF REVIEW

To review the findings of trials evaluating pharmacological treatment approaches for hypertension in general, and resistant hypertension (RH) in particular, and propose future research and clinical directions.

RECENT FINDINGS

RH is defined as blood pressure (BP) that remains above target levels despite adherence to at least three antihypertensive medications, including a diuretic. Thus far, clinical trials of pharmacological approaches in RH have focused on older molecules, with spironolactone being demonstrated as the most efficacious fourth-line agent. However, the use of spironolactone in clinical practice is hampered by its side effect profile and the risk of hyperkalaemia in important RH subgroups, such as patients with moderate-severe chronic kidney disease (CKD). Clinical trials of new molecules targeting both well-established and more recently elucidated pathophysiologic mechanisms of hypertension offer a multitude of potential treatment avenues that warrant further evaluation in the context of RH. These include selective mineralocorticoid receptor antagonists (MRAs), aldosterone synthase inhibitors (ASIs), activators of the counterregulatory renin-angiotensin-system (RAS), vaccines, neprilysin inhibitors alone and in combined formulations, natriuretic peptide receptor agonists A (NPRA-A) agonists, vasoactive intestinal peptide (VIP) agonists, centrally acting aminopeptidase A (APA|) inhibitors, antimicrobial suppression of central sympathetic outflow (minocycline), dopamine β-hydroxylase (DβH) inhibitors and Na+/H+ Exchanger 3 (NHE3) inhibitors. There is a paucity of data from trials evaluating newer molecules for the treatment of RH. Emergent novel molecules for non-resistant forms of hypertension heighten the prospects of identifying new, effective and well-tolerated pharmacological approaches to RH. There is a glaring need to undertake RH-focused trials evaluating their efficacy and clinical applicability.

Resistant and refractory hypertension: two sides of the same disease?

Refractory hypertension (RfH) is an extreme phenotype of resistant hypertension (RH), being considered an uncontrolled blood pressure besides the use of 5 or more antihypertensive medications, including a long-acting thiazide diuretic and a mineralocorticoid antagonist. RH is common, with 10-20% of the general hypertensives, and its associated with renin angiotensin aldosterone system hyperactivity and excess fluid retention. RfH comprises 5-8% of the RH and seems to be influenced by increased sympathetic activity. RH patients are older and more obese than general hypertensives. It is strongly associated with diabetes, obstructive sleep apnea, and hyperaldosteronism status. RfH is more frequent in women, younger patients and Afro-americans compared to RFs. Both are associated with increased albuminuria, left ventricular hypertrophy, chronic kidney diseases, stroke, and cardiovascular diseases. The magnitude of the white-coat effect seems to be higher among RH patients. Intensification of diuretic therapy is indicated in RH, while in RfH, therapy failure imposes new treatment alternatives such as the use of sympatholytic therapies. In conclusion, both RH and RfH constitute challenges in clinical practice and should be addressed as distinct clinical entities by trained professionals who are capable to identify comorbidities and provide specific, diversified, and individualized treatment.