New Molecules for Treating Resistant Hypertension: a Clinical Perspective

Resistant Hypertension: Disease Burden and Emerging Treatment Options

PURPOSE OF REVIEW

To define resistant hypertension (RHT), review its pathophysiology and disease burden, identify barriers to effective hypertension management, and to highlight emerging treatment options.

RECENT FINDINGS

RHT is defined as uncontrolled blood pressure (BP) ≥ 130/80 mm Hg despite concurrent prescription of ≥ 3 or ≥ 4 antihypertensive drugs in different classes or controlled BP despite prescription of  ≥ to 4 drugs, at maximally tolerated doses, including a diuretic. BP is regulated by a complex interplay between the renin-angiotensin-aldosterone system, the sympathetic nervous system, the endothelin system, natriuretic peptides, the arterial vasculature, and the immune system; disruption of any of these can increase BP. RHT is disproportionately manifest in African Americans, older patients, and those with diabetes and/or chronic kidney disease (CKD). Amongst drug-treated hypertensives, only one-quarter have been treated intensively enough (prescribed > 2 drugs) to be considered for this diagnosis. New treatment strategies aimed at novel therapeutic targets include inhibition of sodium-glucose cotransporter 2, aminopeptidase A, aldosterone synthesis, phosphodiesterase 5, xanthine oxidase, and dopamine beta-hydroxylase, as well as soluble guanylate cyclase stimulation, nonsteroidal mineralocorticoid receptor antagonism, and dual endothelin receptor antagonism. The burden of RHT remains high. Better use of currently approved therapies and integrating emerging therapies are welcome additions to the therapeutic armamentarium for addressing needs in high-risk aTRH patients.

Novel Pharmacological Approaches in the Treatment of Hypertension: A Focus on RNA-Based Therapeutics

Hypertension remains the leading cause of cardiovascular disease and premature death globally, affecting half of US adults. A high proportion of hypertensive patients exhibit uncontrolled blood pressure (BP), associated with poor adherence, linked to pill burden and adverse effects. Novel pharmacological strategies are urgently needed to improve BP control. Dysregulation of the renin-angiotensin system increases BP through its primary effector, Ang II (angiotensin II), which results in tissue remodeling and end-organ damage. Silencing liver angiotensinogen (the sole source of Ang II) has been achieved using novel RNA therapeutics, including the antisense oligonucleotide, IONIS-AGT (angiotensinogen)-LRX, and the small-interfering RNA, zilebesiran. Conjugation to N-acetylgalactosamine enables targeted delivery to hepatocytes, where endosomal storage, slow leakage, and small-interfering RNA recycling (for zilebesiran) result in knockdown over several months. Indeed, zilebesiran has an impressive and durable effect on systolic BP, reduced by up to 20 mm Hg and sustained for 6 months after a single administration, likely due to its very effective knockdown of angiotensinogen, without causing acute kidney injury or hyperkalemia. By contrast, IONIS-AGT-LRX caused less knockdown and marginal effects on BP. Future studies should evaluate any loss of efficacy relating to antidrug antibodies, safety issues associated with long-term angiotensinogen suppression, and broader benefits, especially in the context of common comorbidities such as type 2 diabetes and chronic kidney disease.

Maternal Acetate Supplementation Reverses Blood Pressure Increase in Male Offspring Induced by Exposure to Minocycline during Pregnancy and Lactation

Emerging evidence supports that hypertension can be programmed or reprogrammed by maternal nutrition. Maternal exposures during pregnancy, such as maternal nutrition or antibiotic use, could alter the offspring’s gut microbiota. Short-chain fatty acids (SCFAs) are the major gut microbiota-derived metabolites. Acetate, the most dominant SCFA, has shown its antihypertensive effect. Limited information exists regarding whether maternal acetate supplementation can prevent maternal minocycline-induced hypertension in adult offspring. We exposed pregnant Sprague Dawley rats to normal diet (ND), minocycline (MI, 50 mg/kg/day), magnesium acetate (AC, 200 mmol/L in drinking water), and MI + AC from gestation to lactation period. At 12 weeks of age, four groups (n = 8/group) of male progeny were sacrificed. Maternal acetate supplementation protected adult offspring against minocycline-induced hypertension. Minocycline administration reduced plasma acetic acid level, which maternal acetate supplementation prevented. Additionally, acetate supplementation increased the protein level of SCFA receptor G protein-coupled receptor 41 in the offspring kidneys. Further, minocycline administration and acetate supplementation significantly altered gut microbiota composition. Maternal acetate supplementation protected minocycline-induced hypertension accompanying by the increases in genera Roseburia, Bifidobacterium, and Coprococcus. In sum, our results cast new light on targeting gut microbial metabolites as early interventions to prevent the development of hypertension, which could help alleviate the global burden of hypertension.

Firibastat: a Novel Treatment for Hypertension

PURPOSE OF REVIEW

The purpose of this review is to discuss the unique mechanism of firibastat, a new antihypertension medication. Hypertension continues to be a highly prevalent public health issue.

RECENT FINDINGS

Firibastat is a novel agent developed to treat hypertension. As the first member in the class of centrally acting agents to target the brain renin angiotensin system, firibastat offers new pathways to consider and enhances the regimen of agents currently available to treat hypertension. Recent clinical trials have demonstrated effectiveness and safety in mild hypertension as well as resistant hypertension. This review introduces firibastat as a new therapeutic class of treatment for hypertension focused on the renin angiotensin system in the brain. Early studies have shown a significant reduction in blood pressure with minimal side effects particularly in patients who are difficult to treat.