Therapy of hypertension in African Americans

Comparative Effectiveness of Calcium-Channel Blockers, Angiotensin-Converting Enzyme/Angiotensin Receptor Blockers and Diuretics on Cardiovascular Events Likelihood in Hypertensive African-American and Non-Hispanic Caucasians: A Retrospective Study Across HCA Healthcare

BACKGROUND

Hypertension, a leading global risk factor for mortality and disability, disproportionately affects racial and ethnic minorities. Our study investigates the association between the type of prior antihypertensive medication use and the likelihood of cardiovascular events (CVE) and assesses whether the patient's race influences this relationship.

METHODS

A retrospective study of 14 836 hypertension cases aged ≥ 40 years was conducted using data from HCA Healthcare between 2017 and 2023. Logistic regression was employed to predict the likelihood of CVE and mortality at admission, adjusting for baseline comorbidities, with Race added as an effect modifier. Interaction analysis was performed among races based on antihypertensive medication types.

RESULTS

African American patients on ACE inhibitors (ACE) or angiotensin receptor blockers (ARBs) were 1.7 times more likely to have cardiovascular events (CVE) compared to those on calcium channel blockers (CCBs) and 0.66 times as likely compared to diuretics. CCB users had a lower CVE risk than diuretic users. Among White patients, ACE/ARB users had a 1.18 times higher CVE risk than CCB users and 0.45 times lower compared to diuretics, while CCBs offered a 0.38 times lower risk than diuretics. Only ACE/ARB use showed significantly higher CVE odds for African Americans compared to White patients, with similar risks across racial groups for CCBs and diuretics.

CONCLUSION

Prior antihypertensive type significantly influenced CVE risk, with race as an effect modifier. CCB users had lower CVE odds than ACE/ARBs or diuretics, and ACE/ARBs showed reduced CVE likelihood compared to diuretics in both racial groups.

New Approaches Targeting the Renin-Angiotensin System: Inhibition of Brain Aminopeptidase A, ACE2 Ubiquitination, and Angiotensinogen

Despite the availability of various therapeutic classes of antihypertensive drugs, hypertension remains poorly controlled, in part because of poor adherence. Hence, there is a need for the development of antihypertensive drugs acting on new targets to improve control of blood pressure. This review discusses novel insights (including the data of recent clinical trials) with regard to interference with the renin-angiotensin system, focusing on the enzymes aminopeptidase A and angiotensin-converting enzyme 2 (ACE2) in the brain, as well as the substrate of renin- angiotensinogen-in the liver. It raises the possibility that centrally acting amino peptidase A inhibitors (eg, firibastat), preventing the conversion of angiotensin II to angiotensin III in the brain, might be particularly useful in African Americans and patients with obesity. Firibastat additionally upregulates brain ACE2, allowing the conversion of angiotensin II to its protective metabolite angiotensin-(1-7). Furthermore, antisense oligonucleotides or small interfering ribonucleic acids suppress hepatic angiotensinogen for weeks to months after 1 injection and thus could potentially overcome adherence issues. Finally, interference with ACE2 ubiquitination is emerging as a future option for the treatment of neurogenic hypertension, given that ubiquitination resistance might upregulate ACE2 activity.

Racial and Ethnic Disparities in Hypertension: Barriers and Opportunities to Improve Blood Pressure Control

PURPOSE OF REVIEW

To characterize the barriers and opportunities associated with racial and ethnic disparities in blood pressure (BP) control.

RECENT FINDINGS

Blood pressure (BP) control rates in the USA have worsened over the last decade, with significantly lower rates of control among people from racial and ethnic minority groups, with non-Hispanic (NH) Black persons having 10% lower control rates compared to NH White counterparts. Many factors contribute to BP control including key social determinants of health (SDoH) such as health literacy, socioeconomic status, and access to healthcare as well as low awareness rates and dietary habits. Numerous pharmacologic and non-pharmacologic interventions have been developed to reduce racial and ethnic disparities in BP control. Among these, dietary programs designed to help reduce salt intake, faith-based interventions, and community-based programs have found success in achieving better BP control among people from racial and ethnic minority groups. Disparities in the prevalence and management of hypertension persist and remain high, particularly among racial and ethnic minority populations. Ongoing efforts are needed to address SDoH along with the unique genetic, social, economic, and cultural diversity within these groups that contribute to ongoing BP management inequalities.

Vulnerability to Hypertension Is a Major Determinant of Racial Disparities in Alzheimer's Disease Risk

BACKGROUND

Higher incidence levels of Alzheimer's disease (AD) in Black Americans are well documented. However, quantitative explanations of this disparity in terms of risk-factor diseases acting through well-defined pathways are lacking.

METHODS

We applied a Blinder-Oaxaca-based algorithm modified for censored data to a 5% random sample of Medicare beneficiaries age 65+ to explain Black/White disparities in AD risk in terms of differences in exposure and vulnerability to morbidity profiles based on 10 major AD-risk-related diseases.

RESULTS

The primary contribution to racial disparities in AD risk comes from morbidity profiles that included hypertension with about 1/5th of their contribution due to differences in prevalence (exposure effect) and 4/5ths to differences in the effects of the morbidity profile on AD risk (vulnerability effect). In total, disease-related effects explained a higher proportion of AD incidence in Black Americans than in their White counterparts.

CONCLUSIONS

Disease-related causes may represent some of the most straightforward targets for targeted interventions aimed at the reduction of racial disparities in health among US older adults. Hypertension is a manageable and potentially preventable condition responsible for the majority of the Black/White differences in AD risk, making mitigation of the role of this disease in engendering higher AD incidence in Black Americans a prominent concern.

Firibastat: An Oral First-in-Class Brain Aminopeptidase A Inhibitor for Systemic Hypertension

Systemic hypertension is the leading cause of death and disability worldwide. The management of hypertension is challenging in the high-risk patient population with high salt-sensitivity and low serum renin levels. The renin-angiotensin system (RAS) plays a central role in blood pressure (BP) regulation. While we have effective medications to act on peripheral RAS, our understanding of brain RAS and its effect on BP regulation is still in an evolving stage. Brain RAS hyperactivity is associated with the development and maintenance of hypertension. In comparison to peripheral RAS, where angiotensin II is the most crucial component responsible for BP regulation, angiotensin III is likely the main active peptide in the brain RAS. Angiotensin II is metabolized by aminopeptidase A into angiotensin III in the brain. EC33 is a potent inhibitor of brain aminopeptidase A tested in animal models. The use of EC33 in conscious spontaneously hypertensive rats, hypertensive deoxycorticosterone acetate-salt rats, and conscious normotensive rat models leads to a reduction in BP. In order to facilitate the passage of EC33 through the blood-brain barrier, the 2 molecules of EC33 were linked by a disulfide bridge to form a prodrug called RB150. RB150, later renamed as QGC001 or firibastat, was found to be effective in animal models and well-tolerated when used in healthy participants. Firibastat was found to be safe and effective in phase 2 trials, and is now planned to undergo a phase 3 trial. Firibastat has the potential to be groundbreaking in the management of resistant hypertension.

Targeting Brain Aminopeptidase A: A New Strategy for the Treatment of Hypertension and Heart Failure

The pathophysiology of heart failure (HF) and hypertension are thought to involve brain renin-angiotensin system (RAS) hyperactivity. Angiotensin III, a key effector peptide in the brain RAS, provides tonic stimulatory control over blood pressure (BP) in hypertensive rats. Aminopeptidase A (APA), the enzyme responsible for generating brain angiotensin III, constitutes a potential therapeutic target for hypertension treatment. We focus here on studies of RB150/firibastat, the first prodrug of the specific and selective APA inhibitor EC33 able to cross the blood-brain barrier. We consider its development from therapeutic target discovery to clinical trials of the prodrug. After oral administration, firibastat crosses the gastrointestinal and blood-brain barriers. On arrival in the brain, it is cleaved to generate EC33, which inhibits brain APA activity, lowering BP in various experimental models of hypertension. Firibastat was clinically and biologically well tolerated, even at high doses, in phase I trials conducted in healthy human subjects. It was then shown to decrease BP effectively in patients of various ethnic origins with hypertension in phase II trials. Brain RAS hyperactivity leads to excessive sympathetic activity, which can contribute to HF after myocardial infarction (MI). Chronic treatment with oral firibastat (4 or 8 weeks after MI) has been shown to normalize brain APA activity in mice. This effect is accompanied by a normalization of brain RAS and sympathetic activities, reducing cardiac fibrosis and hypertrophy and preventing cardiac dysfunction. Firibastat may therefore represent a novel therapeutic advance in the clinical management of patients with hypertension and potentially with HF after MI.

Evolution of a New Class of Antihypertensive Drugs: Targeting the Brain Renin-Angiotensin System

In addition to the circulating renin-angiotensin system, activation of the brain renin-angiotensin system plays an important role in the pathophysiology of hypertension. One of the major components of the brain renin-angiotensin system implicated in the development of hypertension is Ang III (angiotensin III). Brain Ang III, produced from Ang II (angiotensin II) by APA (aminopeptidase A), exerts a tonic stimulatory control over blood pressure in hypertensive rats. Targeting Ang III by inhibiting brain APA is now considered a potentially important target in the management of hypertension. This has led to development of RB150, an orally active prodrug of the specific and selective APA inhibitor, EC33. Orally administered RB150 crosses the gastrointestinal and blood-brain barriers, enters the brain where it generates 2 active molecules of EC33 that block brain APA activity. This results in decreased brain Ang III formation and reduced blood pressure in hypertensive rats. The RB150-induced blood pressure decrease is due to a reduced vasopressin release, which increases diuresis, reducing extracellular volume, a decrease in sympathetic tone, leading to a reduction of vascular resistances, and the improvement of the baroreflex function. RB150 was renamed firibastat by the World Health Organization. Phase Ia/Ib clinical trials showed that firibastat is clinically and biologically well tolerated in healthy volunteers. Clinical efficacy of firibastat in hypertensive patients was, therefore, demonstrated in 2 phase II studies. Accordingly, firibastat could represent the first drug of a novel class of antihypertensive drugs targeting the brain renin-angiotensin system.

Comparison of Effectiveness of Azilsartan Medoxomil and Olmesartan in Blacks Versus Whites With Systemic Hypertension

Two post hoc analyses in self-identified black and white patients with hypertension evaluated the angiotensin II receptor blocker azilsartan medoxomil (AZL-M) and the fixed-dose combination of AZL-M with chlorthalidone (AZL-M/CLD) versus the ARB olmesartan (OLM) and the OLM fixed-dose combination with hydrochlorothiazide (OLM/HCTZ). One analysis pooled 1,610 patients from two 6-week randomized controlled trials to compare once daily AZL-M 40 mg, AZL-M 80 mg, OLM 40 mg, and placebo. The second analysis included 1,020 patients from a 12-week randomized controlled trial to compare once daily AZL-M/CLD 40/25 mg, AZL-M/CLD 80/25 mg, and OLM/HCTZ 40/25 mg. Efficacy end points were 24-hour mean ambulatory and clinic systolic and diastolic blood pressure (SPB/DBP) and the percentage of patients achieving clinic SBP/DBP targets. Treatment with AZL-M 80 mg lowered mean clinic SBP by 12.5 mm Hg (p <0.01 vs OLM), treatment with AZL-M/CLD 40 mg/25 mg lowered mean ambulatory SBP by 31.0 mm Hg and mean clinic SBP by 39.3 mm Hg (both p <0.05 vs OLM/HCTZ), and treatment with AZL-M/CLD 80 mg/25 mg lowered mean ambulatory SBP by 34.4 mm Hg (p <0.01 vs OLM/HCTZ) and mean clinic SBP by 39.2 mm Hg (p <0.05 vs OLM/HCTZ). Target BP goals were achieved more frequently with AZL-M versus OLM and with AZL-M/CLD versus OLM/HCTZ. In conclusion, in both black and white patients, BP was lowered more effectively with AZL-M versus OLM and with AZL-M/CLD versus OLM/HCTZ. The AZL-M/CLD 40 mg/25 mg combination resulted in a statistically significant reduction in BP in both black and white patients.

Hypertension in African Americans

PURPOSE OF REVIEW

African Americans are over-burdened with hypertension resulting in excess morbidity and mortality. We highlight the health impact of hypertension in this population, review important observations regarding disease pathogenesis, and outline evidence-based treatment, current treatment guidelines, and management approaches.

RECENT FINDINGS

Hypertension accounts for 50% of the racial differences in mortality between Blacks and Whites in the USA. Genome-wide association studies have not clearly identified distinct genetic causes for the excess burden in this population as yet. Pathophysiology is complex likely involving interaction of genetic, biological, and social factors prevalent among African Americans. Non-pharmacologic and pharmacologic therapy is required and specific treatment guidelines for this population are varied. Combination therapy is most often necessary and single-pill formulations are most successful in achieving BP targets. Racial health disparities related to hypertension in African Americans are a serious public health concern that warrants greater attention. Multi-disciplinary research to understand the inter-relationship between biological and social factors is needed to guide successful treatments. Comprehensive care strategies are required to successfully address and eliminate the hypertension burden.

Effects of Age, Sex, and Race on the Safety and Pharmacokinetics of Single and Multiple Doses of Azilsartan Medoxomil in Healthy Subjects

BACKGROUND AND OBJECTIVE

Azilsartan medoxomil (AZL-M) is an angiotensin II receptor blocker approved to treat hypertension. After oral dosing, AZL-M is quickly hydrolyzed to azilsartan (AZL). The aims of this study were to assess the effects of age, sex, and race on the pharmacokinetics of AZL-M in healthy subjects, as well as safety and tolerability.

METHODS

Sixty-one healthy adults were enrolled in this phase I, single-blind, randomized placebo-controlled study (placebo control was for assessment of safety/tolerability only). Subjects were stratified by age (18-45 vs. 65-85 years), sex, and race (black vs. white) and given oral AZL-M 60 mg (3 × 20 mg capsules) or placebo as a single dose (Day 1) and consecutive daily doses (Days 4-8) (6:2 ratio for AZL-M:placebo per group). Pharmacokinetics were evaluated (AZL-M patients only) on Days 1-3 and 8-9 and safety/tolerability was monitored.

RESULTS

Age, sex, and race had no clinically meaningful effect on AZL exposures after single or multiple dosing. Pharmacokinetic parameters remained similar between Days 1 and 8 for each age, sex, and race subgroup. The frequency of adverse events was similar for AZL-M (32%) and placebo (29%). No discontinuations or serious adverse events occurred.

CONCLUSIONS

Based on these pharmacokinetic and safety/tolerability findings, no AZL-M dose adjustments are required based on age, sex, or race (black/white).

Racial differences in microRNA and gene expression in hypertensive women

Systemic arterial hypertension is an important cause of cardiovascular disease morbidity and mortality. African Americans are disproportionately affected by hypertension, in fact the incidence, prevalence, and severity of hypertension is highest among African American (AA) women. Previous data suggests that differential gene expression influences individual susceptibility to selected diseases and we hypothesized that this phenomena may affect health disparities in hypertension. Transcriptional profiling of peripheral blood mononuclear cells from AA or white, normotensive or hypertensive females identified thousands of mRNAs differentially-expressed by race and/or hypertension. Predominant gene expression differences were observed in AA hypertensive females compared to AA normotensives or white hypertensives. Since microRNAs play important roles in regulating gene expression, we profiled global microRNA expression and observed differentially-expressed microRNAs by race and/or hypertension. We identified novel mRNA-microRNA pairs potentially involved in hypertension-related pathways and differently-expressed, including MCL1/miR-20a-5p, APOL3/miR-4763-5p, PLD1/miR-4717-3p, and PLD1/miR-4709-3p. We validated gene expression levels via RT-qPCR and microRNA target validation was performed in primary endothelial cells. Altogether, we identified significant gene expression differences between AA and white female hypertensives and pinpointed novel mRNA-microRNA pairs differentially-expressed by hypertension and race. These differences may contribute to the known disparities in hypertension and may be potential targets for intervention.

Genomic ancestry as a predictor of haemodynamic profile in heart failure

Objective

The aim of this study is to assess the association between genetic ancestry, self-declared race and haemodynamic parameters in patients with chronic heart failure (HF).

Methods

Observational, cross-sectional study. Eligible participants were aged between 18 and 80 years; ejection fraction was ≤50%. Patients underwent genetic analysis of ancestry informative markers, echocardiography and impedance cardiography (ICG). Race was determined by self-classification into two groups: white and non-white. Genomic ancestry was estimated using a panel of 101 348 polymorphic markers and three continental reference populations (European, African and Native American).

Results

Our study included 362 patients with HF between August 2012 and August 2014. 123 patients with HF declared themselves as white and 234 patients declared themselves as non-white. No statistically significant differences were found regarding the ICG parameters according to self-declared race. The Amerindian ancestry was positively correlated with systolic time ratio (r=0.109, p<0.05). The thoracic fluid content index (r=0.124. p<0.05), E wave peak (r=0.127. p<0.05) and E/e′ ratio (r=0.197. p<0.01) were correlated positively with African ancestry. In multiple linear regression, African ancestry remained associated with the E/e′ ratio, even after adjustment to risk factors.

Conclusions

The African genetic ancestry was associated with worse parameters of diastolic function; the Amerindian ancestry correlated with a worse pattern of ventricular contractility, while self-declared colour was not helpful to infer haemodynamic profiles in HF.

Trials registration number

NTC02043431.

Managing type 2 diabetes in Black patients

Despite many novel treatments available for managing type 2 diabetes mellitus, Black patients continue to disproportionately suffer complications associated with poor glycemic control. This article describes a comprehensive approach to managing diabetes mellitus in these patients while addressing cultural nuances that may be barriers to positive outcomes.

Hypertension in the African American population: A succinct look at its epidemiology, pathogenesis, and therapy

Arterial hypertension is prevalent in the black population in the United States. It is directly related to cardiovascular and kidney damage. Its pathogenesis is complex and includes the high incidence of obesity, salt sensitivity and the activation of the renin-angiotensin-aldosterone system. This complexity requires a therapeutic combination that includes changes in dietary habits and appropriate antihypertensive regimes. The International Society of Hypertension in Blacks recommends initiating dietary intervention for values of systolic/diastolic arterial blood pressure above 115/75 mmHg and maintaining arterial blood pressure below 135/85 mmHg using appropiate antihypertensive medication. The most adequate antihypertensive drug for this population has yet to be determined.

Blood pressure control and perceived health status in African Americans with subclinical hypertensive heart disease

The role of antihypertensive therapy in reducing the risk of cardiovascular complications such as heart failure is well established, but the effects of different blood pressure goals on patient-perceived health status has not been well defined. We sought to determine if adverse effects on perceived health status will occur with lower blood pressure goals or more intensive antihypertensive therapy. Data were prospectively collected as a part of a single center, randomized controlled trial designed to evaluate standard (Seventh Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure-compliant) versus intense (<120/80 mm Hg) blood pressure goals for patients with uncontrolled hypertension and subclinical hypertensive heart disease. Blood pressure management was open label, and health status was measured at 3-month intervals over 1 year of follow-up using the short-form (SF)-36. Mixed linear models were constructed for each of the SF-36 summary scores. One hundred twenty-three (mean age 49.4 ± 8.2; 65% female; 95.1% African American) patients were randomized, 88 of whom completed the protocol. With the exception of a decrease in perceived health transition, health status did not change significantly on repeat measurement. Lower blood pressure goals and more intensive antihypertensive therapy appear to be well tolerated with limited effects on patients' perception of health status.

Hypertension in black patients: an update

Black individuals are at high risk for hypertension and increased morbidity from cardiovascular and renal disease, in particular. Increased understanding of racial disparities in hypertension, in terms of risk factors, patient/physician behaviors, and treatment outcomes, is key to improving racially oriented care in black patients. Recent data suggest that black patients progress more rapidly from prehypertension to hypertension, highlighting the need for early and prompt intervention. Unfortunately, adherence to and persistence with antihypertensive therapy are generally poor in black patients and are compounded by the increased need for multidrug therapy in this patient population. Treatment strategies currently under investigation are focusing on methods to improve self-care behaviors and medication adherence. Because this is a constantly and rapidly evolving field of study, this article provides an update of recent findings that should be of relevance and interest to practicing clinicians.

Efficacy and tolerability of initial therapy with single-pill combination telmisartan/hydrochlorothiazide 80/25 mg in patients with grade 2 or 3 hypertension: a multinational, randomized, double-blind, active-controlled trial

BACKGROUND

Patients with grade 2 or 3 hypertension may require high-dose combination therapy to achieve blood pressure (BP) targets in a timely manner.

OBJECTIVES

This study compared the effectiveness and tolerability of a single-pill combination (SPC) of telmisartan/hydrochlorothiazide 80/25 mg (T80/H25) with T80 monotherapy.

METHODS

In a Phase IV, multinational, randomized, double-blind, double-dummy, active-controlled, parallel-group trial, 894 patients with mean seated trough cuff systolic BP [SBP] ≥160 mm Hg and diastolic BP [DBP] ≥100 mm Hg were randomly assigned in a 2:1 ratio to receive T40/H12.5 SPC or telmisartan 40 mg monotherapy for 1 week before the dose was uptitrated to T80/H25 SPC or T80, respectively, administered for 6 weeks. The primary efficacy measure was the change from baseline in mean seated cuff trough SBP. Adverse events (AEs) were recorded.

RESULTS

A total of 888 patients received treatment (294 and 594 patients in the T80/H25 and T80 groups, respectively) (mean age, 57.0 years; age ≥65 years, 25.7%; male, 53.8%; white, 68.0%); 61 patients prematurely discontinued. Mean baseline SBP/DBP values were 172.3/104.3 mm Hg (T80/H25) and 173.3/104.5 mm Hg (T80). After 7 weeks, SBP was changed by -37.0 and -28.5 mm Hg in the T80/H25 and T80 groups (P < 0.0001); DBP was changed by -18.6 and -15.4 mm Hg respectively (P < 0.0001). These differences were significant after 2 weeks at the higher dosage (P < 0.0001). BP target (SBP/DBP <140/<90 mm Hg) was achieved in 55.5% and 34.7% of patients in the T80/H25 and T80 groups (P < 0.0001). T80/H25 SPC and T80 had a similar frequency of overall AEs (16.0% vs 17.0%). The prevalences of treatment-related AEs with T80/H25 SPC and T80 were low (4.6% and 2.8%), as were the rates of AEs that led to discontinuation (1.0% and 2.8%).

CONCLUSIONS

In these patients with grade 2 or 3 hypertension, initial therapy with T80/H25 was associated with a significantly greater reduction in mean seated cuff trough SBP compared with T80 alone, as well as with improved hypertension goal attainment rates. Both treatments appeared to be well tolerated.