Regional and racial differences in response to antihypertensive medication use in a randomized controlled trial of men with hypertension in the United States. Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents

Trends in Initial Antihypertensive Medication Prescribing Among >2.8 Million Veterans Newly Diagnosed With Hypertension, 2000 to 2019

BACKGROUND

Among patients diagnosed with high blood pressure (BP), initial dual therapy has been recommended for patients with high pretreatment systolic BP (≥160 mm Hg) since 2003, and first-line β-blocker use without a compelling condition has fallen out of favor in US guidelines.

METHODS AND RESULTS

This serial cross-sectional study of national Veterans Health Administration data included adult Veterans with incident hypertension initiating antihypertensive medication between January 1, 2000, and December 31, 2019. We assessed annual trends in initial regimens dispensed (index date: first antihypertensive dispense date) by number of classes and unique class combinations used overall and by pretreatment systolic BP (<140, 140 to <160, and ≥160 mm Hg), as well as trends in subgroups (age, sex, race and ethnicity, and comorbidities warranting β-blocker use). Among 2 832 684 eligible Veterans (average age 61 years, 95% men, 65% non-Hispanic White, and 8% with cardiovascular disease), from 2000-2004 to 2015-2019, initial monotherapy increased across all pretreatment systolic BP levels (<140 mm Hg: 62.1% to 66.4%; 140 to <160 mm Hg: 70.7% to 76.8%; ≥160 mm Hg: 64.2% to 69.7%). Initiation of dual therapy decreased across all pretreatment systolic BP levels (<140 mm Hg: 25.0% to 24.2%; 140 to <160 mm Hg: 20.4% to 17.6%; ≥160 mm Hg: 22.7% to 22.0%). Among 2 521 696 Veterans (89% of overall) without a β-blocker-indicated condition in 2015 to 2019, 20% initiated a β-blocker, most commonly as monotherapy.

CONCLUSIONS

More than half of US Veterans diagnosed with hypertension with a pretreatment systolic BP ≥160 mm Hg were started on antihypertensive monotherapy. There are disparities between guideline-recommended first-line treatments and the actual regimens initiated for newly diagnosed Veterans with hypertension.

Racial and Ethnic Disparities in Antihypertensive Medication Prescribing Patterns and Effectiveness

Variability in drug effectiveness and provider prescribing patterns have been reported in different racial and ethnic populations. We sought to evaluate antihypertensive drug effectiveness and prescribing patterns among self-identified Hispanic/Latino (Hispanic), Non-Hispanic Black (Black), and Non-Hispanic White (White) populations that enrolled in the NIH All of Us Research Program, a US longitudinal cohort. We employed a self-controlled case study method using electronic health record and survey data from 17,718 White, Hispanic, and Black participants who were diagnosed with essential hypertension and prescribed at least one of 19 commonly used antihypertensive medications. Effectiveness was determined by calculating the reduction in systolic blood pressure measurements after 28 or more days of drug exposure. Starting systolic blood pressure and effectiveness for each medication were compared for self-reported Black, Hispanic, and White participants using adjusted linear regressions. Black and Hispanic participants were started on antihypertensive medications at significantly higher SBP than White participants in 13 and 7 out of 19 medications, respectively. More Black participants were prescribed multiple antihypertensive medications (58.46%) than White (52.35%) or Hispanic (49.9%) participants. First-line HTN medications differed by race and ethnicity. Following the 2017 American College of Cardiology and the American Heart Association High Blood Pressure Guideline release, around 64% of Black participants were prescribed a recommended first-line antihypertensive drug compared with 76% of White and 82% of Hispanic participants. Effect sizes suggested that most antihypertensive drugs were less effective in Hispanic and Black, compared with White, participants, and statistical significance was reached in 6 out of 19 drugs. These results indicate that Black and Hispanic populations may benefit from earlier intervention and screening and highlight the potential benefits of personalizing first-line medications.

The gut microbiome as a modulator of arterial function and age-related arterial dysfunction

The arterial system is integral to the proper function of all other organs and tissues. Arterial function is impaired with aging, and arterial dysfunction contributes to the development of numerous age-related diseases, including cardiovascular diseases. The gut microbiome has emerged as an important regulator of both normal host physiological function and impairments in function with aging. The purpose of this review is to summarize more recently published literature demonstrating the role of the gut microbiome in supporting normal arterial development and function and in modulating arterial dysfunction with aging in the absence of overt disease. The gut microbiome can be altered due to a variety of exposures, including physiological aging processes. We explore mechanisms by which the gut microbiome may contribute to age-related arterial dysfunction, with a focus on changes in various gut microbiome-related compounds in circulation. In addition, we discuss how modulating circulating levels of these compounds may be a viable therapeutic approach for improving artery function with aging. Finally, we identify and discuss various experimental considerations and research gaps/areas of future research.

Should Renal Inflammation Be Targeted While Treating Hypertension?

Despite extensive research and a plethora of therapeutic options, hypertension continues to be a global burden. Understanding of the pathological roles of known and underexplored cellular and molecular pathways in the development and maintenance of hypertension is critical to advance the field. Immune system overactivation and inflammation in the kidneys are proposed alternative mechanisms of hypertension, and resistant hypertension. Consideration of the pathophysiology of hypertension in chronic inflammatory conditions such as autoimmune diseases, in which patients present with autoimmune-mediated kidney inflammation as well as hypertension, may reveal possible contributors and novel therapeutic targets. In this review, we 1) summarize current therapies used to control blood pressure and their known effects on inflammation; 2) provide evidence on the need to target renal inflammation, specifically, and especially when first-line and combinatory treatment efforts fail; and 3) discuss the efficacy of therapies used to treat autoimmune diseases with a hypertension/renal component. We aim to elucidate the potential of targeting renal inflammation in certain subsets of patients resistant to current therapies.

Angiotensin-Converting Enzyme Inhibitor and Angiotensin Receptor Blocker Use Associated with Reduced Mortality and Other Disease Outcomes in US Veterans with COVID-19

Objective

To determine the association between angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) use and coronavirus disease 2019 (COVID-19) severity and outcomes in US veterans.

Patients and Methods

We retrospectively examined 27,556 adult US veterans who tested positive for COVID-19 between March to November 2020. Logistic regression and Cox proportional hazards models using propensity score (PS) for weight, adjustment, and matching were used to examine the odds of an event within 60 days following a COVID-19–positive case date and time to death, respectively, according to ACEI and/or ARB prescription within 6 months prior to the COVID-19–positive case date.

Results

The overlap PS weighted logistic regression model showed lower odds of an intensive care unit (ICU) admission (odds ratio [OR] 95% CI 0.77, 0.61–0.98) and death within 60 days (0.87, 0.79–0.97) with an ACEI or ARB prescription. Veterans with an ARB-only prescription also had lower odds of an ICU admission (0.64, 0.44–0.92). The overlap PS weighted model similarly showed a lower risk of time to all-cause mortality in veterans with an ACEI or ARB prescription (HR [95% CI]: 0.87, 0.79–0.97) and an ARB only prescription (0.78, 0.67–0.91). Veterans with an ACEI prescription had higher odds of experiencing a septic event within 60 days after the COVID-19–positive case date (1.22, 1.02–1.46).

Conclusion

In this study of a national cohort of US veterans, we found that the use of an ACEI/ARB in patients with COVID-19 was not associated with increased mortality and other worse outcomes. Future studies should examine underlying pathways and further confirm the relationship of ACEI prescription with sepsis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40265-021-01639-2.

The Effect of Nebivolol on Office Blood Pressure of Blacks Residing in Sub-Saharan Africa (A Pilot Study)

Introduction: There is substantial clinical evidence that monotherapy with beta-blockers are less effective in reducing blood pressure among hypertensive Black patients compared to Whites. The highly selective beta-1 agents like nebivolol and bisoprolol have, however, been reported to be effective in reducing blood pressure in African Americans. However, results in African Americans cannot be extrapolated to native Africans because of genetic admixture and gene-environment interaction. There is, therefore, the need for us to generate data that are applicable to Africans residing in sub-Saharan Africa. We therefore decided to evaluate the efficacy and tolerability of highly selective beta-1 agent nebivolol in hypertensive Black patients residing in sub-Saharan Africa. Materials and Methods: The nebivolol study was a multicenter, prospective, observational program among hypertensive patients with 4- and 8-week follow up which was conducted in 5 cities in Nigeria of Abuja, Calabar, Enugu, Oghara, and Port Harcourt. Dosages of nebivolol used in keeping with local prescribing information were 5 and 10 mg once daily each. The effectiveness of treatment was assessed by change from baseline in mean office systolic and diastolic blood pressures, and the proportion of patients achieving the therapeutic goal of <140/90 mmHg. Safety and tolerability of this medication were also assessed. Results: We report the results of the 140 patients studied. The mean age and body mass index were 46.9 ± 7.3 years and 22.3 ± 5.8 kg/m², respectively, and 57.1% were female. Nebivolol reduced SBP and DBP by 7.6 and 6.6 mmHg, respectively, in 4 weeks, and by 11.1 and 8.0 mm Hg, respectively, in 8 weeks. Blood pressure control was achieved in 54.8% of the patients in 4 weeks and increased to 60.4% in 8 weeks. There was no change in metabolic profile between randomization and at 8 weeks, and erectile dysfunction occurred in 1.3% of the study population. Conclusions: Nebivolol 5 and 10 mg appear efficacious in Nigerian Africans with no negative metabolic effect and minimal side effect profile. Clinical Trial Registration: www.ClinicalTrials.gov, Study Identification: NCT03598673.

Association of Race/Ethnicity-Specific Changes in Antihypertensive Medication Classes Initiated Among Medicare Beneficiaries With the Eighth Joint National Committee Panel Member Report

IMPORTANCE

In December 2013, the panel members appointed to the Eighth Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC8) published a recommendation that non-Black adults initiate antihypertensive medication with a thiazide-type diuretic, calcium channel blocker, angiotensin-converting enzyme inhibitor (ACEI), or angiotensin receptor blocker (ARB), whereas Black adults initiate treatment with a thiazide-type diuretic or calcium channel blocker. β-Blockers were not recommended as first-line therapy.

OBJECTIVE

To assess changes in antihypertensive medication classes initiated by race/ethnicity from before to after publication of the JNC8 panel member report.

DESIGN, SETTING, AND PARTICIPANTS

This serial cross-sectional analysis assessed a 5% sample of Medicare beneficiaries aged 66 years or older who initiated antihypertensive medication between 2011 and 2018, were Black (n = 3303 [8.0%]), White (n = 34 943 [84.5%]), or of other (n = 3094 [7.5%]) race/ethnicity, and did not have compelling indications for specific antihypertensive medication classes.

EXPOSURES

Calendar year and period after vs before publication of the JNC8 panel member report.

MAIN OUTCOMES AND MEASURES

The proportion of beneficiaries initiating ACEIs or ARBs and, separately, β-blockers vs other antihypertensive medication classes.

RESULTS

In total, 41 340 Medicare beneficiaries (65% women; mean [SD] age, 75.7 [7.6] years) of Black, White, or other races/ethnicities initiated antihypertensive medication and met the inclusion criteria for the present study. In 2011, 25.2% of Black beneficiaries initiating antihypertensive monotherapy did so with an ACEI or ARB compared with 23.7% in 2018 (P = .47 for trend). Among beneficiaries initiating monotherapy, the proportion filling a β-blocker was 20.1% in 2011 and 15.4% in 2018 for White beneficiaries (P < .001 for trend), 14.2% in 2011 and 11.1% in 2018 for Black beneficiaries (P = .08 for trend), and 11.3% in 2011 and 15.0% in 2018 for beneficiaries of other race/ethnicity (P = .40 for trend). After multivariable adjustment and among beneficiaries initiating monotherapy, there was no evidence of a change in the proportion filling an ACEI or ARB before to after publication of the JNC8 panel member report overall (prevalence ratio, 1.00; 95% CI, 0.97-1.03) or in Black vs White beneficiaries (prevalence ratio, 0.96; 95% CI, 0.83-1.12; P = .60 for interaction). Among beneficiaries initiating monotherapy, the proportion filling a β-blocker decreased from before to after publication of the JNC8 panel member report (prevalence ratio, 0.89; 95% CI, 0.84-0.93) with no differences across race/ethnicity groups (P > .10 for interaction).

CONCLUSIONS AND RELEVANCE

A substantial proportion of older US adults who initiate antihypertensive medication do so with non-guideline-recommended classes of medication.

Regional variations in cardiovascular risk factors and access to care among US veterans with cardiovascular disease

BACKGROUND

It remains unclear whether cardiovascular risk factors and access to healthcare for veterans with cardiovascular disease (CVD) vary among US regions. This study sought to determine the extent of regional variations in cardiovascular risk factors and access to medical care in a cohort of veterans with CVD in the USA.

METHODS

The 2016 Centers for Disease Control Behavioral Risk Factor Surveillance Survey was utilized to identify a cohort of veteran patients with CVD. Participants were classified based on four US regions: (1) Northeast, (2) Midwest, (3) South, and (4) West. We compared demographic data, medical history, and access to care for veterans of each US region. The outcomes of interest included financial barriers to medical care and annual medical checkup.

RESULTS

Among the 13 835 veterans, 18.3% were from the Northeast, while 23.5, 37.1, and 21.1% were from the Midwest, South, and West, respectively. Veterans of each region differed significantly with respect to demographic characteristics, prior medical history, and access to care. Rates of financial barriers to medical care were similar across the four regions (7.3 vs. 7.1 vs. 8.0 vs. 6.9%, P = 0.203). Veterans from the West had the lowest rates of medical checkup within the past year (91.7 vs. 89.5 vs. 91.4 vs. 86.6%). On multivariate analysis, the Midwest [odds ratio (OR) 0.69; 95% CI, 0.53-0.89] and West (OR 0.53; 95% CI 0.41-0.68) regions were independently associated with lower rates of medical checkup within the past year compared to the Northeast.

CONCLUSIONS

In this observational study involving US veterans with CVD, cardiovascular risk factors and frequency of annual medical checkup differed amongst each US region. Further large-scale studies examining the prevalence of impaired access to care and quality of care in US veterans with CVD are warranted.

Polymorphic variation in the SLC5A7 gene influences infant autonomic reactivity and self-regulation: A neurobiological model for ANS stress responsivity and infant temperament

OBJECTIVE

To examine the impact of polymorphic variation in the solute carrier family 5 member 7 (SLC5A7) gene on autonomic nervous system (ANS) reactivity indexed by respiratory sinus arrhythmia (RSA) and heart rate (HR) in infants during a dyadic stressor, as well as maternal report of infant self-regulation. Given evidence of race differences in older individuals, race was specifically examined.

METHODS

RSA and HR were collected from 111 infants during the still-face paradigm (SFP). Mothers completed the Infant Behavior Questionnaire-Revised short-form. Multi-level mixed effects models examined the impact of SLC5A7 genotype on RSA and HR across the SFP. Linear models tested the influence of genotype on the relation between RSA, HR, and maternal report of infant self-regulation.

RESULTS

SLC5A7 genotype significantly predicted RSA stress responsivity (β = -0.023; p = 0.028) and HR stress responsivity (β = 0.004; p = 0.002). T-allele carriers exhibited RSA suppression and HR acceleration in response to stress while G/G homozygotes did not suppress RSA and exhibited less HR acceleration. All infants exhibited modest RSA augmentation and HR deceleration during recovery. Race-stratified analyses revealed that White T-allele carriers drove the overall results for both RSA (β = -0.044; p = 0.007) and HR (β = 0.006; p = 0.008) with no relation between SLC5A7 genotype and RSA or HR in Black infants. Maternal report of infant orienting/regulation was predicted by the interaction of SLC5A7 genotype and both RSA recovery (β = 0.359; p = 0.001) and HR recovery (β = -1.659; p = 0.020). RSA augmentation and HR deceleration during recovery were associated with higher maternal reports of self-regulation among T-allele carriers, a finding again primarily driven by White infants.

CONCLUSIONS

Early in development, genetic contributions to ANS are evident and predict maternal report of infant self-regulation within White infants, consistent with prior literature. The lack of associations in Black infants suggest that race differences in physiological reactivity and self-regulation are emerging during the first year of life potentially providing early evidence of disparities in health risk trajectories.

Insights on β-blockers for the treatment of hypertension: A survey of health care practitioners

A quantitative survey was completed by 103 primary care physicians (PCPs) and 59 cardiologists who regularly prescribed β-blockers to assess knowledge and use of this heterogeneous drug class for hypertension. More cardiologists than PCPs chose β-blockers as initial antihypertensive therapy (30% vs 17%, P < 0.01). Metoprolol and carvedilol were the most commonly prescribed β-blockers. Cardiologists rated "impact on energy" and "arterial vasodilation" as more important than PCPs (P < 0.05/<0.01, respectively). Awareness of vasodilation was greater for carvedilol (52%) than nebivolol (31%). Association between β-blockers and clinical variables included nebivolol with β₁ -selectivity, nebivolol and carvedilol with vasodilation and efficacy in older patients and African Americans, metoprolol with heart rate reduction, and atenolol and metoprolol with weight gain and hyperglycemia. Physicians preferred prescribing β-blockers with lower risk of incident diabetes. Clinical practice guidelines influenced physician prescribing more than formularies or performance metrics. This survey captures physicians' perceptions/use of various β-blockers and clinically relevant knowledge gaps.

Research Participation of a Professional Organization in Clinical Trials: The Association of Black cardiologists Clinical Trial Investigator Identification Project

INTRODUCTION

Black individuals continue to be underrepresented in clinical trials despite efforts by the National Institutes of Health and the Federal Drug Administration to increase their enrollment. Health care providers play a critical role in the recruitment of patients into clinical trials, as they have established relationships and are uniquely positioned to make referrals for participation. While prior initiatives have focused on training black physicians to conduct clinical research, we sought to determine the potential of utilizing a professional organization as a resource to identify established investigators to champion recruitment of underrepresented racial and ethnic populations. The Association of Black Cardiologists (ABC) is a non-profit organization with a mission to eliminate racial and ethnic disparities in cardiovascular disease and may provide a conduit for recruiting investigators. The purpose of this study was to examine the feasibility of using the ABC membership to identify investigators with an established track record in clinical trials.

METHODS/RESULTS

Utilizing a roster of ABC members, we searched Scopus to quantify ABC member publications from 1999 to 2015 and identify members who have been active in clinical trials. Within the membership of 2037 individuals, we identified 794 with peer-reviewed publications, and 109 who co-authored manuscripts involving randomized clinical trials. The manuscripts largely focused on hypertension and heart failure, conditions that have a disproportionately greater affect on black individuals.

CONCLUSION

Members of the ABC have varied amounts of research productivity. We identified a group of experienced investigators to engage in efforts aimed at recruiting/enrolling underrepresented racial and ethnic populations in clinical trials of cardiovascular disease.

Population differences in associations of serotonin transporter promoter polymorphism (5HTTLPR) di- and triallelic genotypes with blood pressure and hypertension prevalence

Based on prior research finding the 5HTTLPR L allele associated with increased cardiovascular reactivity to laboratory stressors and increased risk of myocardial infarction, we hypothesized that the 5HTTLPR L allele will be associated with increased blood pressure (BP) and increased hypertension prevalence in 2 large nationally representative samples in the United States and Singapore.

METHODS

Logistic regression and linear models tested associations between triallelic (L'S', based on rs25531) 5HTTLPR genotypes and hypertension severity and mean systolic and diastolic blood pressure (SBP and DBP) collected during the Wave IV survey of the National Longitudinal Study of Adolescent to Adult Health (Add Health, N=11,815) in 2008-09 and during 2004-07 in 4196 Singaporeans.

RESULTS

In US Whites, L' allele carriers had higher SBP (0.9 mm Hg, 95% CI=0.26-1.56) and greater odds (OR=1.23, 95% CI=1.10-1.38) of more severe hypertension than those with S'S' genotypes. In African Americans, L' carriers had lower mean SBP (-1.27mm Hg, 95% CI=-2.53 to -0.01) and lower odds (OR = 0.78, 95% CI=0.65-0.94) of more severe hypertension than those with the S'S' genotype. In African Americans, those with L'L' genotypes had lower DBP (-1.13mm Hg, 95% CI=-2.09 to -0.16) than S' carriers. In Native Americans, L' carriers had lower SBP (-6.05mm Hg, 95% CI=-9.59 to -2.51) and lower odds of hypertension (OR = 0.34, 95% CI=0.13-0.89) than those with the S'S' genotype. In Asian/Pacific Islanders those carrying the L' allele had lower DBP (-1.77mm Hg, 95% CI=-3.16 to -0.38) and lower odds of hypertension (OR = 0.68, 95% CI=0.48-0.96) than those with S'S'. In the Singapore sample S' carriers had higher SBP (3.02mm Hg, 95% CI=0.54-5.51) and DBP (1.90mm Hg, 95% CI=0.49-3.31) than those with the L'L' genotype.

CONCLUSIONS

These findings suggest that Whites carrying the L' allele, African Americans and Native Americans with the S'S' genotype, and Asians carrying the S' allele will be found to be at higher risk of developing cardiovascular disease and may benefit from preventive measures.

Hypertension Treatment in Blacks: Discussion of the U.S. Clinical Practice Guidelines

Blacks are especially susceptible to hypertension (HTN) and its associated organ damage leading to adverse cardiovascular, cerebrovascular and renal outcomes. Accordingly, HTN is particularly significant in contributing to the black-white racial differences in health outcomes in the US. As such, in order to address these health disparities, practical clinical practice guidelines (CPGs) on how to treat HTN, specifically in blacks, are needed. This review article is a timely addition to the literature because the most recent U.S. CPG more explicitly emphasizes race into the algorithmic management of HTN. However, recent clinical research cautions that use of race as a proxy to determine therapeutic response to pharmaceutical agents may be erroneous. This review will address the implications of the use of race in the hypertension CPGs. We will review the rationale behind the introduction of race into the U.S. CPG and the level of evidence that was available to justify this introduction. Finally, we will conclude with practical considerations in the treatment of HTN in blacks.

Comparison of Monotherapy with Irbesartan 150 mg or Amlodipine 5 mg for Treatment of Mild-to-Moderate Hypertension

Objective. The primary objective of this study was to compare the antihypertensive efficacy of the angiotensin II receptor blocker irbesartan 150 mg and the calcium channel blocker amlodipine 5 mg in the treatment of patients with seated diastolic blood pressure (DBP) 95—110 mmHg.

Design. Multicentre, randomised, double-blind, comparative pilot study.

Methods. Subjects were 18—65 years of age, with DBP 95—110 mmHg, and of non-African American origin. Following a three-week, single-blind, placebo lead-in period, 181 subjects were randomised in a 1:1 ratio to receive once-daily irbesartan 150 mg (n=89) or amlodipine 5 mg (n=92) for four weeks. Trough (24±3 hours post-dosing) BP measurements were obtained at baseline and at Weeks 2 and 4 under standardised, controlled conditions. Response was defined as DBP <90 mmHg or a reductionfrom baseline of ≥10 mmHg.

Results. After four weeks of treatment, the mean (±SE) decrease from baseline in DBP was 9.4±0.6 mmHg in the irbesartan group vs. 9.6±0.6 mmHg in the amlodipine group (p=0.806). The mean decrease from baseline in seated systolic BP was 12.2±1.0 mmHg in the irbesartan group vs. 12.0±1.0 mmHg in the amlodipine group (p=0.885). Overall, 62% of subjects in the irbesartan group and 63% in the amlodipine group had a response (p=0.609), and 54% and 56% of patients (p=0.596), respectively, had their DBP normalised (<90 mmHg). Adverse events were reported by 21.3% of patients receiving irbesartan and 20.7% receiving amlodipine.

Conclusions. Irbesartan 150 mg demonstrated comparable efficacy to amlodipine 5 mg, thereby confirming its value as an antihypertensive treatment option in non-African American patients with DBP 95—110 mmHg.

Mechanisms of Vascular Smooth Muscle Contraction and the Basis for Pharmacologic Treatment of Smooth Muscle Disorders

The smooth muscle cell directly drives the contraction of the vascular wall and hence regulates the size of the blood vessel lumen. We review here the current understanding of the molecular mechanisms by which agonists, therapeutics, and diseases regulate contractility of the vascular smooth muscle cell and we place this within the context of whole body function. We also discuss the implications for personalized medicine and highlight specific potential target molecules that may provide opportunities for the future development of new therapeutics to regulate vascular function.

Systolic blood pressure response after high-intensity interval exercise is independently related to decreased small arterial elasticity in normotensive African American women

Aerobic exercise transiently lowers blood pressure. However, limited research has concurrently evaluated blood pressure and small arterial elasticity (SAE), an index of endothelial function, among African American (AA) and European American (EA) women the morning after (i.e., ≈22 h later) acute bouts of moderate-intensity continuous (MIC) and high-intensity interval (HII) exercise matched for total work. Because of greater gradients of shear stress, it was hypothesized that HII exercise would elicit a greater reduction in systolic blood pressure (SBP) compared to MIC exercise. After baseline, 22 AA and EA women initiated aerobic exercise training 3 times/week. Beginning at week 8, three follow-up assessments were conducted over the next 8 weeks at random to measure resting blood pressure and SAE. In total all participants completed 16 weeks of training. Follow-up evaluations were made: (i) in the trained state (TS; 8-16 weeks of aerobic training); (ii) ≈22 h after an acute bout of MIC exercise; and (iii) ≈22 h after an acute bout of HII exercise. Among AAs, the acute bout of HII exercise incited a significant increase in SBP (mm Hg) (TS, 121 ± 14 versus HII, 128 ± 14; p = 0.01) whereas responses (TS, 116 ± 12 versus HII, 113 ± 9; p = 0.34) did not differ in EAs. After adjusting for race, changes in SAE were associated (partial r = -0.533; p = 0.01) with changes in SBP following HII exercise. These data demonstrate an acute, unaccustomed bout of HII exercise produces physiological perturbations resulting in a significant increase in SBP that are independently associated with decreased SAE among AA women, but not EA women.

Regional and physician specialty-associated variations in the medical management of atherosclerotic renal-artery stenosis

For people enrolled in Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL), we sought to examine whether variation exists in the baseline medical therapy of different geographic regions and if any variations in prescribing patterns were associated with physician specialty. Patients were grouped by location within the United States (US) and outside the US (OUS), which includes Canada, South America, Europe, South Africa, New Zealand, and Australia. When comparing US to OUS, participants in the US took fewer anti-hypertensive medications (1.9 ± 1.5 vs. 2.4 ± 1.4; P < .001) and were less likely to be treated with an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker (46% vs. 62%; P < .001), calcium channel antagonist (37% vs. 58%; P < .001), and statin (64% vs. 75%; P < .05). In CORAL, the identification of variations in baseline medical therapy suggests that substantial opportunities exist to improve the medical management of patients with atherosclerotic renal-artery stenosis.

Low rate of resistant hypertension in Chinese patients with hypertension: an analysis of the HOT-CHINA study

Objective:

The rate of resistant hypertension in China is unknown. This is an analysis of resistant hypertension based on Hypertension Optimal Treatment Study in China.

Methods:

The study was conducted in 148 cities in mainland China from April 2001 to February 2002, which included 54 590 hypertensive patients (≥18 years of age), and used a five-step treatment programme. Patients not achieving blood pressure (BP) target (<140/90 mmHg) within 2 weeks received preplanned additional drugs. Resistant hypertension was defined in the participants with uncontrolled hypertension after 2 weeks of treatment on Step 5.

Results:

The rate of resistant hypertension was 1.9%. Patients with resistant hypertension were characterized by following features: higher male percentage (65.6 vs. 60.2%); younger age (59.51 ± 13.02 vs. 61.76 ± 12.27 years); higher BMI (24.8 ± 3.5 vs. 24.0 ± 3.4 kg/m²); longer disease course; higher fasting blood glucose (6.60 ± 2.69 vs. 5.99 ± 2.12 mmol/l); higher total cholesterol (5.67 ± 1.63 vs. 5.32 ± 1.24 mmol/l); higher triglycerides (2.15 ± 1.32 vs. 1.96 ± 1.09 mmol/l); and higher percentage of grade 3 hypertension (71.1 vs. 27.2%) (all P < 0.001). Patients with resistant hypertension also had a higher rate of metabolic syndrome (45.9 vs. 35.4%), diabetes mellitus (25.5 vs. 14.7%) and history of myocardial infarction (4.7 vs. 3.3%) or stroke (17.0 vs. 11.6%) (P < 0.001). Multivariate analyses revealed an association of resistant hypertension with younger age, higher BP, BMI, longer disease course, higher fasting blood glucose and total cholesterol (P < 0.05).

Conclusion:

Resistant hypertension in Chinese patients is associated with overweight/obesity, higher BP and metabolic syndrome. The rate of resistant hypertension in China, however, is much lower than previously reported. Another intriguing characteristic is the association of resistant hypertension with younger age.

Urinary angiotensinogen excretion is associated with blood pressure independent of the circulating renin-angiotensin system in a group of african ancestry

Although the circulating renin-angiotensin system (RAS) is suppressed in salt-sensitive populations, the role of the intrarenal RAS in blood pressure (BP) control in these groups independent of the circulating RAS is uncertain. We evaluated the relationship between 24-hour urinary angiotensinogen excretion and either office (mean of 5 measurements; n=425) or 24-hour ambulatory (n=340) BP independent of the circulating RAS in a community-based sample of African descent that had never received antihypertensive drug therapy. Circulating RAS activity was determined from plasma renin and angiotensinogen and serum aldosterone concentrations. Urinary angiotensinogen to creatinine ratio (angiotensinogen/creat) was correlated with plasma angiotensinogen concentrations (P<0.0005) but not with indexes of salt intake. However, urinary angiotensinogen/creat was independently associated with office systolic BP (partial r=0.16; P<0.001), whereas plasma angiotensinogen (partial r=0.07; P=0.14) was not independently associated with office systolic BP. Urinary angiotensinogen/creat was also associated with 24-hour systolic BP (partial r=0.11; P<0.05). The relationships between urinary angiotensinogen/creat and BP survived further adjustments for plasma angiotensinogen and serum aldosterone concentrations, plasma renin concentrations, estimated glomerular filtration rate, urinary Na(+)/K(+), or 24-hour urinary Na(+) excretion rates (P<0.005 for all). Participants with the highest compared with the lowest quartile of urinary angiotensinogen/creat showed an 8.2-mm Hg higher office (P<0.005) and 4.6-mm Hg higher 24-hour (P=0.01) systolic BP. In conclusion, independent of the systemic RAS, including plasma angiotensinogen concentrations, urinary angiotensinogen excretion is associated with BP in a salt-sensitive, low-renin group of African descent. These data lend further support for a role of the RAS in BP control in salt-sensitive groups of African ancestry.

Race contributes to beta-blocker efficacy in pediatric patients with arrhythmias

In African-American (AA) adults, β-blockers (BB) have been reported to be less efficacious treating cardiac disease compared with whites (CAUC). This has been attributed to genetic polymorphisms of β-receptors. It is unknown if racial differences affect response to BB in pediatric patients with arrhythmias. AA and CAUC ≤ 18 years of age were included if they underwent treadmill stress testing while receiving metoprolol, atenolol, nadolol, or carvedilol. Patient demographics, resting heart rate (HR), maximum HR, and BB variables were collected. CAUC patients were matched on a 2:1 basis by age and sex to AA patients. Patients were blunted if HR was <90 % of maximum predicted HR for same-age patients on a modified Bruce protocol treadmill stress test. Long-term follow-up for breakthrough arrhythmias was documented. 78 patients were included (26 AA, 52 CAUC). No differences were noted in demographics, medication dose, BB or arrhythmia type, or baseline, maximal, or % HR change (p = not significant [NS]). On univariate analysis, fewer AA achieved a blunted HR during treadmill testing compared with CAUC (65 vs. 86%, p = 0.03). On multivariate analysis, AA were less likely to have an HR blunted by BB (OR 0.18, 95% confidence interval [CI] 0.04-0.75, p = 0.02) compared with CAUC. During the 1-year follow-up period, AA trended toward having one (58 vs. 40%, p = 0.14) or multiple instances (38 vs. 26%, p = 0.26) of breakthrough arrhythmia on cardiac Holter monitor testing. Race appears to affect the efficacy of BB therapy in pediatric patients with arrhythmias. Future studies to identify genetic polymorphisms in this patient subset are necessary.

Hypertension and hypertensive heart disease in African women

Hypertension and hypertensive heart disease is one of the main contributors to a growing burden of non-communicable forms of cardiovascular disease around the globe. The recently published global burden of disease series showed a 33 % increase of hypertensive disorders in pregnancy in the past two decades with long-term consequences. Africans, particularly younger African women, appear to be bearing the brunt of this increasing public health problem. Hypertensive heart disease is particularly problematic in pregnancy and is an important contributor to maternal case-fatality. European physicians increasingly need to attend to patients from African decent and need to know about unique aspects of disease presentation and pharmacological as well as non-pharmacological care. Reductions in salt consumption, as well as timely detection and treatment of hypertension and hypertensive heart disease remain a priority for effective primary and secondary prevention of CVD (particularly stroke and CHF) in African women. This article reviews the pattern, potential causes and consequences and treatment of hypertension and hypertensive heart disease in African women, identifying the key challenges for effective primary and secondary prevention in this regard.

Factors associated with the prevalence of hypertension in the southeastern United States: insights from 69,211 blacks and whites in the Southern Community Cohort Study

BACKGROUND

Lifestyle and socioeconomic status have been implicated in the prevalence of hypertension; thus, we evaluated factors associated with hypertension in a cohort of blacks and whites with similar socioeconomic status characteristics.

METHODS AND RESULTS

We evaluated the prevalence and factors associated with self-reported hypertension (SR-HTN) and ascertained hypertension (A-HTN) among 69,211 participants in the Southern Community Cohort Study. Multivariable logistic regression models were used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for factors associated with hypertension. The prevalence of SR-HTN was 57% overall. Body mass index was associated with SR-HTN in all race-sex groups, with the OR rising to 4.03 (95% CI, 3.74-4.33) for morbidly obese participants (body mass index, >40 kg/m(2)). Blacks were more likely to have SR-HTN than whites (OR, 1.84; 95% CI, 1.75-1.93), and the association with black race was more pronounced among women (OR, 2.08; 95% CI, 1.95-2.21) than men (OR, 1.47; 95% CI, 1.36-1.60). Similar findings were noted in the analysis of A-HTN. Among those with SR-HTN and A-HTN who reported use of an antihypertensive agent, 94% were on at least one of the major classes of antihypertensive agents, but only 44% were on ≥2 classes and only 29% were on a diuretic. The odds of both uncontrolled hypertension (SR-HTN and A-HTN) and unreported hypertension (no SR-HTN and A-HTN) were twice as high among blacks as whites (OR, 2.13; 95% CI, 1.68-2.69; and OR, 1.99; 95% CI, 1.59-2.48, respectively).

CONCLUSIONS

Despite socioeconomic status similarities, we observed suboptimal use of antihypertensives in this cohort and racial differences in the prevalence of uncontrolled and unreported hypertension, which merit further investigation.

Effect of duration and age at exposure to the Stroke Belt on incident stroke in adulthood

OBJECTIVE

To assess whether there are differences in the strength of association with incident stroke for specific periods of life in the Stroke Belt (SB).

METHODS

The risk of stroke was studied in 24,544 black and white stroke-free participants, aged 45+, in the Reasons for Geographic and Racial Differences in Stroke study, a national population-based cohort enrolled 2003-2007. Incident stroke was defined as first occurrence of stroke over an average 5.8 years of follow-up. Residential histories (city/state) were obtained by questionnaire. SB exposure was quantified by combinations of SB birthplace and current residence and proportion of years in SB during discrete age categories (0-12, 13-18, 19-30, 31-45, last 20 years) and entire life. Proportional hazards models were used to establish association of incident stroke with indices of exposure to SB, adjusted for demographic, socioeconomic (SES), and stroke risk factors.

RESULTS

In the demographic and SES models, risk of stroke was significantly associated with proportion of life in the SB and with all other exposure periods except birth, ages 31-45, and current residence. The strongest association was for the proportion of the entire life in SB. After adjustment for risk factors, the risk of stroke remained significantly associated only with proportion of residence in SB in adolescence (hazard ratio 1.17, 95% confidence interval 1.00-1.37).

CONCLUSIONS

Childhood emerged as the most important period of vulnerability to SB residence as a predictor of future stroke. Improvement in childhood health circumstances should be considered as part of long-term health improvement strategies in the SB.

Pharmacometabolomics reveals racial differences in response to atenolol treatment

Antihypertensive drugs are among the most commonly prescribed drugs for chronic disease worldwide. The response to antihypertensive drugs varies substantially between individuals and important factors such as race that contribute to this heterogeneity are poorly understood. In this study we use metabolomics, a global biochemical approach to investigate biochemical changes induced by the beta-adrenergic receptor blocker atenolol in Caucasians and African Americans. Plasma from individuals treated with atenolol was collected at baseline (untreated) and after a 9 week treatment period and analyzed using a GC-TOF metabolomics platform. The metabolomic signature of atenolol exposure included saturated (palmitic), monounsaturated (oleic, palmitoleic) and polyunsaturated (arachidonic, linoleic) free fatty acids, which decreased in Caucasians after treatment but were not different in African Americans (p<0.0005, q<0.03). Similarly, the ketone body 3-hydroxybutyrate was significantly decreased in Caucasians by 33% (p<0.0001, q<0.0001) but was unchanged in African Americans. The contribution of genetic variation in genes that encode lipases to the racial differences in atenolol-induced changes in fatty acids was examined. SNP rs9652472 in LIPC was found to be associated with the change in oleic acid in Caucasians (p<0.0005) but not African Americans, whereas the PLA2G4C SNP rs7250148 associated with oleic acid change in African Americans (p<0.0001) but not Caucasians. Together, these data indicate that atenolol-induced changes in the metabolome are dependent on race and genotype. This study represents a first step of a pharmacometabolomic approach to phenotype patients with hypertension and gain mechanistic insights into racial variability in changes that occur with atenolol treatment, which may influence response to the drug.

The role of vasodilating β-blockers in patients with complicated hypertension: focus on nebivolol

Despite their proven mortality and morbidity outcomes benefits, β-blockers remain substantially underused in patients with cardiac conditions. Reluctance to prescribe β-blockers may be owing to concerns about tolerability with the traditional drugs in this class. β-blockers with vasodilatory properties, such as carvedilol and nebivolol, may overcome the tolerability and metabolic issues associated with traditional β-blockers. Because endothelial dysfunction, the pathophysiologic hallmark of hypertension, may be heightened in populations with difficult-totreat hypertension (e.g., elderly patients, African American patients), a vasodilating β-blocker may be a particularly appropriate choice for these patient groups.

The role of G protein β3 subunit polymorphisms C825T, C1429T, and G5177A in Turkish subjects with essential hypertension

Hypertension is a multifactorial disorder that constitutes a major risk factor for the cardiovascular system. Heterotrimeric G-proteins, which couple receptors for diverse extracellular enzymes or ion channels, are correlated with disease mechanisms. Several studies have demonstrated an association between G protein polymorphisms and essential hypertension in some populations, although contradictive results also exist. In this study, we have investigated the potential role of the C825T, C1429T, and G5177A polymorphisms of the β3 subunit of G-proteins in essential hypertension in a group of Turkish subjects. Genomic DNA from 106 normotensive individuals (117.4 ± 13.1, 75.2 ± 10.5; systolic blood pressure (SBP) and diastolic blood pressure (DBP) levels, respectively) and 101 hypertensive subjects (152.3 ± 18.0, 92.5 ± 11.6; SBP and DBP levels, respectively) were studied by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and direct sequencing methods for these polymorphisms. Allele frequencies of the polymorphisms were consistent with Hardy Weinberg equilibrium, except for the C825T polymorphism (χ(2) = 7.8). The frequencies of the 825T and 1429T variants were higher in hypertensive subjects compared to those of controls. Differences between hypertensives and controls were not statistically significant, though difference was very close to significance for C825T (p = 0.056 and 0.099 for 825T and 1429T, respectively). T allele frequency in overall population showed significant association with hypertension for C825T (0.0134). The prevalence of the 5177A-variant was very low and all subjects carrying it were heterozygotes in both groups.

The role of vasodilating beta-blockers in patients with complicated hypertension: focus on nebivolol

Despite their proven mortality and morbidity outcomes benefits, beta-blockers remain substantially underused in patients with cardiac conditions. Reluctance to prescribe beta-blockers may be owing to concerns about tolerability with the traditional drugs in this class. Beta-blockers with vasodilatory properties, such as carvedilol and nebivolol, may overcome the tolerability and metabolic issues associated with traditional beta-blockers. Because endothelial dysfunction, the pathophysiologic hallmark of hypertension, may be heightened in populations with difficult-to-treat hypertension (e.g., elderly patients, African American patients), a vasodilating beta-blocker may be a particularly appropriate choice for these patient groups.

Impact of blood pressure lowering on cardiovascular outcomes in normal weight, overweight, and obese individuals: the Perindopril Protection Against Recurrent Stroke Study trial

There is considerable uncertainty regarding the efficacy of blood pressure-lowering therapy in reducing cardiovascular risk in obese people. In this report we examine the effects of blood pressure lowering according to baseline body mass index (kilograms per meter squared) in the Perindopril Protection Against Recurrent Stroke Study. A total of 6105 participants with cerebrovascular disease were randomized to perindopril-based blood pressure-lowering therapy or placebo. The overall mean difference in systolic/diastolic blood pressure between participants assigned active therapy or placebo was 9/4 mm Hg (SE: 0.5/0.3 mm Hg), with no difference by body mass index quarters (<23.1, 23.1 to 25.3, 25.4 to 27.8, and > or = 27.9 kg/m(2)). A consistent treatment benefit was demonstrated for protection against major vascular events across quarters with the following hazard ratios (95% CIs): 0.80 (0.62 to 1.02), 0.78 (0.61 to 1.01), 0.67 (0.53 to 0.86), 0.69 (0.54 to 0.88), and 0.74 (0.66 to 0.84; P for heterogeneity=0.16). Similar results were apparent for stroke and stroke subtypes (all P for heterogeneity > or = 0.07) or with the standard definitions of overweight and obesity (<25, 25 to 29, and > or = 30 kg/m(2); all P for heterogeneity > or = 0.28). The absolute effects of treatment were, however, more than twice that in the highest compared with the lowest body mass index quartile. Across increasing quarters of body mass index over 5 years, active therapy prevented 1 major vascular event among every 28, 23, 13, and 13 patients treated. In conclusion, blood pressure-lowering therapy produced comparable risk reductions in vascular disease across the whole range of body mass indices in participants with a history of stroke. However, the greater baseline level of cardiovascular risk in those with higher body mass index meant that these patients obtained the greatest benefit.

Estimating antihypertensive effects of combination therapy in an observational study using marginal structural models

The evaluation of the antihypertensive effect of multiple antihypertensive drugs using data from an observational study requires adjustment for time-dependent confounders. Marginal structural models (MSMs) have been proposed to address this type of confounding through inverse probability weighting. Generally, the probabilities are estimated using logistic regression models that assume linearity between the logistic link and the predictors, but the linearity might be inaccurate. In this article, we proposed MSMs to assess the blood pressure-lowering effects of combination therapy with olmesartan medoxomil (OLM) plus calcium channel blockers (CCB) (OLM+CCB) in an observational study of OLM, and extended estimation methods of the probabilities for the MSMs using generalized additive models (GAMs). The estimation using GAMs was suggested to improve the balance of the distributions of confounder values between the therapy groups in the pseudo-population. We obtained estimated changes in systolic blood pressure (SBP) and diastolic blood pressure (DBP) for OLM+CCB combination therapy after 12 wk compared with OLM monotherapy of -4.3 mmHg (95% confidence interval (CI): -7.7 and -0.9 mmHg) and -2.9 mmHg (95% CI: -5.1 and -0.7 mmHg), respectively. The estimated target BP (SBP<140 mmHg and DBP<90 mmHg) achievement rates for OLM+CCB combination therapy and OLM monotherapy were 62.0 and 46.7%, respectively. The results of the MSMs were closer to those in the randomized controlled trial, such as the combination of OLM and amlodipine besylate in controlling high blood pressure study, than those of conventional methods. The proposed MSMs provided useful information to evaluate the effects of combination therapy of antihypertensive drugs in the context of an observational study.

CYP3A4 and CYP3A5 polymorphisms and blood pressure response to amlodipine among African-American men and women with early hypertensive renal disease

PURPOSE

To explore the association between CYP3A4 and CYP3A5 gene polymorphisms and blood pressure response to amlodipine among participants from the African-American Study of Kidney Disease and Hypertension Trial randomized to amlodipine (n = 164).

METHODS

Cox proportional hazards models were used to determine the risk of reaching a target mean arterial pressure (MAP) of < or =107 mm Hg by CYP3A4 (A-392G and T16090C) and CYP3A5 (A6986G) gene polymorphisms, stratified by MAP randomization group (low or usual) and controlling for other predictors for blood pressure response.

RESULTS

Women randomized to a usual MAP goal with an A allele at CYP3A4 A-392G were more likely to reach a target MAP of 107 mm Hg. The adjusted hazard ratio (AA/AG compared to GG) with 95% confidence interval was 3.41 (1.20-9.64; p = 0.020). Among participants randomized to a lower MAP goal, those with the C allele at CYP3A4 T16090C were more likely to reach target MAP: The adjusted hazard ratio was 2.04 (1.17-3.56; p = 0.010). After adjustment for multiple testing using a threshold significance level of p = 0.016, only the CYP3A4 T16090C SNP remained significant. CYP3A5 A6986G was not associated with blood pressure response.

CONCLUSIONS

Our findings suggest that blood pressure response to amlodipine among high-risk African-Americans appears to be determined by CYP3A4 genotypes, and sex specificity may be an important consideration. Clinical applications of CYP3A4 genotype testing for individualized treatment regimens warrant further study.

Effect of treatment and adherence on ethnic differences in blood pressure control among adults with hypertension

We evaluated whether hypertension control differs by ethnicity after accounting for patient characteristics, treatment, and adherence to treatment using the third National Health and Nutrition Examination Survey (US population estimate, 42,511,379). Outcome measures were prescribed treatment, treatment adherence, hypertension control (blood pressure [BP]<140/90 mm Hg). Multivariate logistic regression was performed with non-Hispanic whites (NHW) as the comparison group. Non-Hispanic blacks (NHB) were more likely to report medication prescription (odds ratio [OR] 1.6, 95% confidence interval [CI] 1.1-2.5) and being advised to restrict salt (OR 1.5, CI: 1.2-2.0). Among those advised, NHB were more likely to report salt restriction (OR 1.5, CI: 1.1-2.1) and weight-loss attempts (OR 1.7, CI: 1.3-2.3). Among persons advised to follow exercise, alcohol restriction, smoking cessation, tension reduction, or diet modification, NHB (OR 2.2, CI: 1.6-3.0) and Mexican Americans (OR 2.0, CI: 1.1-3.9) were more likely to report adherence. The likelihood of uncontrolled hypertension was higher in NHB (OR 1.4, CI: 1.1-1.7) and Mexican Americans (OR 1.5, CI 1.1-2.0) despite medication adherence. Even after adjustment for treatment and adherence, substantial ethnic differences in hypertension control were found. Initiating treatment, while crucial, is not sufficient and future guidelines should emphasize aggressive treatment escalation to achieve hypertension control.

Spouses' effectiveness as end-of-life health care surrogates: accuracy, uncertainty, and errors of overtreatment or undertreatment

PURPOSE

We document the extent to which older adults accurately report their spouses' end-of-life treatment preferences, in the hypothetical scenarios of terminal illness with severe physical pain and terminal illness with severe cognitive impairment. We investigate the extent to which accurate reports, inaccurate reports (i.e., errors of undertreatment or overtreatment), and uncertain reports (responses of "do not know") are associated with spouses' advance care planning and surrogates' involvement in the planning.

DESIGN AND METHODS

We used data from married couples who participated in the Wisconsin Longitudinal Study in 2004. These 2,750 couples were in their mid-60s and in relatively good health. We conducted multinomial logistic regressions.

RESULTS

Surrogates were accurate in the majority of cases, made errors in 12% to 22% of cases, and were uncertain in 11% to 16% of cases. Errors of overtreatment and undertreatment were equally prevalent. For both scenarios, discussing preferences was associated with lower odds of an uncertain surrogate response.

IMPLICATIONS

We suggest ways that health care practitioners could facilitate family-level conversations in order to ensure that patients' preferences are accurately represented in end-of-life care settings.

Combination therapy versus monotherapy as initial treatment for stage 2 hypertension: a prespecified subgroup analysis of a community-based, randomized, open-label trial

BACKGROUND

Current guidelines suggest consideration of initial combination therapy for patients with stage 2 hypertension, but rates of hypertension treatment and control in clinical practice vary according to age, race, sex, and body mass index (BMI).

OBJECTIVE

This was a prespecified subgroup analysis of one of the primary efficacy end points-mean change in systolic blood pressure (SBP) at 6 weeks -in a previously published community-based, randomized, open-label trial comparing valsartan monotherapy with valsartan/hydrochlorothiazide (HCTZ) combination therapy as initial treatment for high-risk patients with stage 2 hypertension.

METHODS

Eligible participants with stage 2 hypertension (SBP >or=160 mm Hg and/or diastolic blood pressure [DBP] >or=100 mm Hg) were treated with valsartan 160 mg/d or valsartan/HCTZ 160/12.5 mg/d for 2 weeks, followed by forced titration to valsartan 320 mg/d or valsartan/HCTZ 320/12.5 mg/d for an additional 4 weeks. In addition to the primary blood pressure end point (change in SBP at 6 weeks), secondary blood pressure end points at 6 weeks included changes in DBP and the proportion of patients achieving a blood pressure control threshold of <140/90 mm Hg (<130/80 mm Hg for patients with diabetes), as recommended by the Seventh Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7). The subgroups of interest were women, blacks, Hispanics, the elderly (age >or=65 years), patients with diabetes, smokers, and lean, overweight, and obese subjects (BMI <25, 25-<30, and =30 kg/m(2), respectively).

RESULTS

The randomized trial included 1668 patients (756 [45.3%] female, 392 [23.5%] black, 109 [6.5%] Hispanic, 220 [13.2%] elderly, 970 of 1641 [59.1%] obese, 166 [10.0%] with diabetes, 467 [28.0%] smokers) with stage 2 hypertension. Among those allocated to combination therapy compared with monotherapy, the mean (SD) change in SBP at 6 weeks was -27.4 (18.5) and -19.3 (17.7) mm Hg in women, -21.4 (17.6) and -12.6 (18.5) mm Hg in black subjects, -21.7 (17.6) and -16.3 (16.5) mm Hg in Hispanic subjects, -25.5 (20.2) and -16.9 (17.9) mm Hg in the elderly, and -23.6 (18.1) and -15.9 (16.2) mm Hg in obese subjects. With the exception of the results for Hispanics, all comparisons of combination therapy and monotherapy were statistically significant (P<or=0.01). A higher proportion of those receiving valsartan/ HCTZ compared with valsartan monotherapy reached the JNC 7-defined blood pressure goal (44.5% vs 29.1%, respectively; P<0.001). This pattern was seen consistently in most subgroups analyzed, including men (41.8% vs 27.9%; P<0.001), women (47.8% vs 30.5%; P<0.001), white subjects (46.4% vs 33.8%; P<0.001), black subjects (41.8% vs 19.1%; P<0.001), those aged <65 years (44.6% vs 29.7%; P<0.001), those aged >or=65 years (43.9% vs 24.5%; P=0.004), overweight subjects (49.0% vs 31.2%; P<0.001), and obese subjects (41.4% vs 26.0%; P<0.001). In the entire study cohort, patients assigned to combination therapy had a significantly higher incidence of dizziness compared with those assigned to monotherapy (8.5% vs 4.7%; P=0.002); however, there was no statistically significant difference in the frequency of adverse events between treatment groups in the prespecified subgroups.

CONCLUSIONS

Across various subgroups of patients with stage 2 hypertension, combination therapy was consistently associated with a significantly greater reduction in SBP than monotherapy. With the exception of a significantly greater increase in dizziness compared with monotherapy, combination therapy was well tolerated.

Beta-1-adrenoceptor genetic variants and ethnicity independently affect response to beta-blockade

OBJECTIVES

Black patients may be less responsive to beta-blockers than whites. Genetic variants in the beta1-adrenergic receptor (beta1-AR) associated with lesser response to beta-blockers are more common in blacks than in whites. The purpose of this study was to determine whether ethnic differences in response to beta-blockade can be explained by differing distributions of functional genetic variants in the beta1-AR.

METHODS

We measured sensitivity to beta-blockade by the attenuation of exercise-induced tachycardia in 165 patients (92 whites), who performed a graded bicycle exercise test before and 2.5 h after oral atenolol (25 mg). We determined heart rate at rest and at three exercise levels from continuous ECG recordings and calculated the area under the curve. We also measured plasma atenolol concentrations and determined genotypes for variants of the beta1-AR (Ser49Gly, Arg389Gly) and alpha2C-AR (del322-325). The effects of ethnicity, genotype, and other covariates on the heart rate reduction after atenolol were estimated in multiple regression analyses.

RESULTS

Atenolol resulted in a greater reduction in exercise heart rate in whites than in blacks (P=0.006). beta1-AR Arg389 (P=0.003), but not the alpha2C-AR 322-325 insertion allele (P=0.31), was independently associated with a greater reduction in heart rate area under the curve. Ethnic differences in sensitivity to atenolol remained significant (P=0.006) after adjustment for beta1-AR and alpha2C-AR genotypes.

CONCLUSION

Ethnic differences in sensitivity to the beta1-blocker atenolol persist even after accounting for different distributions of functional genetic beta1-AR variants, suggesting that additional, as yet unidentified factors contribute to such ethnic differences.