Differing mechanisms of action of angiotensin-converting enzyme inhibition in black and white hypertensive patients. The Trandolapril Multicenter Study Group

Racial Differences in Blood Pressure Control from Users of Antihypertensive Monotherapy: Results from the ELSA-Brasil Study

BACKGROUND

It seems that the worst response to some classes of antihypertensive drugs, especially angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, on the part of the Black population, would at least partially explain the worse control of hypertension among these individuals. However, most of the evidence comes from American studies.

OBJECTIVES

This study aims to investigate the association between self-reported race/skin color and BP control in participants of the Longitudinal Study of Adult Health (ELSA-Brasil), using different classes of antihypertensive drugs in monotherapy.

METHODS

The study involved a cross-sectional analysis, carried out with participants from the baseline of ELSA-Brasil. Blood pressure control was the response variable, participants with BP values ≥140/90 mmHg were considered out of control in relation to blood pressure levels. Race/skin color was self-reported (White, Brown, Black). All participants were asked about the continuous use of medication. Association between BP control and race/skin color was estimated through logistic regression. The level of significance adopted in this study was of 5%.

RESULTS

Of the total of 1,795 users of antihypertensive drugs in monotherapy at baseline, 55.5% declared themselves White, 27.9% Brown, and 16.7% Black. Even after adjusting for confounding variables, Blacks using angiotensin converting enzyme inhibitors (ACEI), angiotensin receptor blocker (ARB), thiazide diuretics (thiazide DIU), and beta-blockers (BB) in monotherapy had worse blood pressure control compared to Whites.

CONCLUSIONS

Our results suggest that in this sample of Brazilian adults using antihypertensive drugs in monotherapy, the differences in blood pressure control between different racial groups are not explained by the possible lower effectiveness of ACEIs and ARBs in Black individuals.

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.

Ethnic Disparities in Thrombotic and Bleeding Diatheses Revisited: A Systematic Review of Microsurgical Breast Reconstruction across the East and West

BACKGROUND

 Ethnicity has been shown to play a role in disparate coagulative responses between East Asian and Caucasian patients undergoing nonmicrovascular surgery. In this study, we sought to further investigate this hematologic phenomenon between the two ethnic groups within the field of microsurgical breast reconstruction.

METHODS

 A systematic review examining the reported incidence of microvascular thrombosis and all-site bleeding among breast free flaps in East Asians and Westerners was performed. Statistical analysis was performed using the chi-square test.

RESULTS

 Ten East Asian studies with 581 flaps and 99 Western studies with 30,767 flaps were included. A statistically significant higher rate of thrombotic complications was found in Westerners compared with East Asians (4.2 vs. 2.2%, p = 0.02). Conversely, bleeding events were more common in East Asians compared with Westerners (2.6 vs. 1.2%, p = 0.002).

CONCLUSION

 There appears to be an ethnicity-based propensity for thrombosis in Westerners and, conversely, for bleeding in East Asians, as evident by the current systematic review of microvascular breast reconstruction data. It is therefore advisable to consider ethnicity in the comprehensive evaluation of patients undergoing microsurgical procedures.

Impact of carboxylesterase 1 genetic polymorphism on trandolapril activation in human liver and the pharmacokinetics and pharmacodynamics in healthy volunteers

Trandolapril, an angiotensin-converting enzyme inhibitor prodrug, needs to be activated by carboxylesterase 1 (CES1) in the liver to exert its intended therapeutic effect. A previous in vitro study demonstrated that the CES1 genetic variant G143E (rs71647871) abolished CES1-mediated trandolapril activation in cells transfected with the variant. This study aimed to determine the effect of the G143E variant on trandolapril activation in human livers and the pharmacokinetics (PKs) and pharmacodynamics (PDs) in human subjects. We performed an in vitro incubation study to assess trandolapril activation in human livers (5 G143E heterozygotes and 97 noncarriers) and conducted a single-dose (1 mg) PK and PD study of trandolapril in healthy volunteers (8 G143E heterozygotes and 11 noncarriers). The incubation study revealed that the mean trandolapril activation rate in G143E heterozygous livers was 42% of those not carrying the variant (p = 0.0015). The clinical study showed that, relative to noncarriers, G143E carriers exhibited 20% and 15% decreases, respectively, in the peak concentration (Cmax ) and area under the curve from 0 to 72 h (AUC0-72 h ) of the active metabolite trandolaprilat, although the differences were not statistically significant. Additionally, the average maximum reductions of systolic blood pressure and diastolic blood pressure in carriers were ~ 22% and 23% less than in noncarriers, respectively, but the differences did not reach a statistically significant level. In summary, the CES1 G143E variant markedly impaired trandolapril activation in the human liver under the in vitro incubation conditions; however, this variant had only a modest impact on the PK and PD of trandolapril in healthy human subjects.

Non-Communicable Diseases on the Rise in Sub-Saharan Africa, the Underappreciated Threat of a Dual Disease Burden

In sub-Saharan Africa, the burden of non-communicable diseases (NCDs) remains under appreciated, but emerging evidence suggests it to be substantial. NCDs such as arterial hypertension, heart diseases, diabetes mellitus and chronic kidney diseases are especially relevant, and put additional strain on the already challenged health systems in this region. Moreover, NCDs appear to be associated with higher mortality and morbidity rates and are more common in younger population groups, in people from sub-Saharan Africa when compared to more developed countries. In this review, we summarize the current literature on the burden of NCDs in sub-Saharan Africa, and highlight the clinical implications of the most relevant etiologies, i.e. arterial hypertension, heart diseases, diabetes mellitus and chronic kidney diseases.

Hypertensive APOL1 risk allele carriers demonstrate greater blood pressure reduction with angiotensin receptor blockade compared to low risk carriers

Background

Hypertension (HTN) disproportionately affects African Americans (AAs), who respond better to thiazide diuretics than other antihypertensives. Variants of the APOL1 gene found in AAs are associated with a higher rate of kidney disease and play a complex role in cardiovascular disease.

Methods

AA subjects from four HTN trials (n = 961) (GERA1, GERA2, PEAR1, and PEAR2) were evaluated for blood pressure (BP) response based on APOL1 genotype after 4–9 weeks of monotherapy with thiazides, beta blockers, or candesartan. APOL1 G1 and G2 variants were determined by direct sequencing or imputation.

Results

Baseline systolic BP (SBP) and diastolic BP (DBP) levels did not differ based on APOL1 genotype. Subjects with 1–2 APOL1 risk alleles had a greater SBP response to candesartan (-12.2 +/- 1.2 vs -7.5 +/- 1.8 mmHg, p = 0.03; GERA2), and a greater decline in albuminuria with candesartan (-8.3 +/- 3.1 vs +3.7 +/- 4.3 mg/day, p = 0.02). APOL1 genotype did not associate with BP response to thiazides or beta blockers. GWAS was performed to determine associations with BP response to candesartan depending on APOL1 genotype. While no SNPs reached genome wide significance, SNP rs10113352, intronic in CSMD1, predicted greater office SBP response to candesartan (p = 3.7 x 10⁻⁷) in those with 1–2 risk alleles, while SNP rs286856, intronic in DPP6, predicted greater office SBP response (p = 3.2 x 10⁻⁷) in those with 0 risk alleles.

Conclusions

Hypertensive AAs without overt kidney disease who carry 1 or more APOL1 risk variants have a greater BP and albuminuria reduction in response to candesartan therapy. BP response to thiazides or beta blockers did not differ by APOL1 genotype. Future studies confirming this initial finding in an independent cohort are required.

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.

Managing hypertension in type 2 diabetes mellitus

Hypertension is a common problem in the diabetic population with estimates suggesting a prevalence exceeding 60%. Comorbid hypertension and diabetes mellitus are associated with high rates of macrovascular and microvascular complications. These two pathologies share overlapping risk factors, importantly central obesity. Treatment of hypertension is unequivocally beneficial and improves all-cause mortality, cardiovascular mortality, major cardiovascular events, and microvascular outcomes including nephropathy and retinopathy. Although controversial, current guidelines recommend a target blood pressure in the diabetic population of <140/90 mmHg, which is a similar target to that proposed for individuals without diabetes. Management of blood pressure in patients with diabetes includes both lifestyle modifications and pharmacological therapies. This article reviews the evidence for management of hypertension in patients with type 2 diabetes mellitus, and provides a recommended treatment strategy based on the available data.

Understanding the Importance of Race/Ethnicity in the Care of the Hypertensive Patient

Although several risk factors contribute to cardiovascular disease (CVD) overall, hypertension (HTN) is the major controllable risk factor. Hypertension is disproportionately more prevalent among Blacks or African-Americans compared with other race/ethnic populations, and the control rates among this disparate population are alarming. Several pathophysiologic mechanisms have been demonstrated and evaluated among hypertensives and the conglomeration of genetics, environmental, and personal lifestyle activities concurrently impact the progression of hypertension-related comorbidities (i.e., chronic renal disease, CVD, stroke, etc.). Specific pharmacotherapeutic choices are discussed and the most up-to-date data is presented to optimize the care of hypertensives. National and international guidelines for the treatment of HTN are reviewed and analyzed, presenting the most appropriate approach to the care of hypertensive patients overall. Additionally, national efforts supporting the goal of early HTN screening and treatment, as well as the variety of evidence-based pharmacotherapy, are summarized, applying to the public health impact overall.

Outcomes with Angiotensin-converting Enzyme Inhibitors vs Other Antihypertensive Agents in Hypertensive Blacks

BACKGROUND

Angiotensin-converting enzyme inhibitors are used widely in the treatment of patients with hypertension. However, their efficacy in hypertensive blacks when compared with other antihypertensive agents is not well established.

METHODS

We performed a cohort study of patients using data from a clinical data warehouse of 434,646 patients from New York City's Health and Hospitals Corporation from January 2004 to December 2009. Patients were divided into the following comparison groups: angiotensin-converting enzyme inhibitors vs calcium channel blockers, angiotensin-converting enzyme inhibitors vs thiazide diuretics, and angiotensin-converting enzyme inhibitors vs β-blockers. The primary outcome was a composite of death, myocardial infarction, and stroke. Secondary outcomes included the individual components and heart failure.

RESULTS

In the propensity score-matched angiotensin-converting enzyme inhibitors vs calcium channel blocker comparison cohort (4506 blacks in each group), angiotensin-converting enzyme inhibitors were associated with a higher risk of primary outcome (hazard ratio [HR], 1.45; 95% confidence interval [CI], 1.19-1.77; P = .0003), myocardial infarction (HR, 3.40; 95% CI, 1.25-9.22; P = .02), stroke (HR, 1.82; 95% CI, 1.29-2.57; P = .001), and heart failure (HR, 1.77; 95% CI, 1.30-2.42; P = .0003) when compared with calcium channel blockers. For the angiotensin-converting enzyme inhibitors vs thiazide diuretics comparison (5337 blacks in each group), angiotensin-converting enzyme inhibitors were associated with a higher risk of primary outcome (HR, 1.65; 95% CI, 1.33-2.05; P < .0001), death (HR, 1.35; 95% CI, 1.03-1.76; P = .03), myocardial infarction (HR, 4.00; 95% CI, 1.34-11.96; P = .01), stroke (HR, 1.97; 95% CI, 1.34-2.92; P = .001), and heart failure (HR, 3.00; 95% CI, 1.99-4.54; P < .0001). For the angiotensin-converting enzyme inhibitors vs β-blocker comparison, the outcomes between the groups were not significantly different.

CONCLUSIONS

In a real-world cohort of hypertensive blacks, angiotensin-converting enzyme inhibitors were associated with a higher risk of cardiovascular events when compared with calcium channel blockers or thiazide diuretics.

Race, common genetic variation, and therapeutic response disparities in heart failure

Because of its comparatively recent evolution, Homo sapiens exhibit relatively little within-species genomic diversity. However, because of genome size, a proportionately small amount of variation creates ample opportunities for both rare mutations that may cause disease as well as more common genetic variations that may be important in disease modification or pharmacogenetics. Primarily because of the East African origin of modern humans, individuals of African ancestry (AA) exhibit greater degrees of genetic diversity than more recently established populations, such as those of European ancestry (EA) or Asian ancestry. Those population effects extend to differences in frequency of common gene variants that may be important in heart failure natural history or therapy. For cell-signaling mechanisms important in heart failure, we review and present new data for genetic variation between AA and EA populations. Data indicate that: 1) neurohormonal signaling mechanisms frequently (16 of the 19 investigated polymorphisms) exhibit racial differences in the allele frequencies of variants comprising key constituents; 2) some of these differences in allele frequency may differentially affect the natural history of heart failure in AA compared with EA individuals; and 3) in many cases, these differences likely play a role in observed racial differences in drug or device response.

High salt-induced hypertension in B2 knockout mice is corrected by the ETA antagonist, A127722

BACKGROUND AND PURPOSE

The contribution of endothelin-1 (ET-1) in a B2KO mouse model of a high salt-induced arterial hypertension was investigated.

EXPERIMENTAL APPROACH

Wild-type (WT) or B2KO mice receiving a normal diet (ND) or a high-salt diet (HSD) were monitored by radiotelemetry up to a maximum of 18 weeks. At the 12th week of diet, subgroups under ND or HSD received by gavage the ETA antagonist A127722 during 5 days. In addition, blood samples were collected and, following euthanasia, the lungs, heart and kidneys were extracted, homogenized and assayed for ET-1 by RIA. In a separate series of experiments, the ETA antagonist, BQ123 was tested against the pressor responses to a NOS inhibitor L-N(G)-nitroarginine methyl ester (L-NAME) in anaesthetized WT and B2KO mice.

KEY RESULTS

In B2KO, but not WT mice, 12 weeks of HSD triggered a maximal increase of the mean arterial pressure (MAP) of 19.1 ± 2.8 mmHg, which was corrected by A127722 to MAP levels found in B2KO mice under ND. Significant increases in immunoreactive ET-1 were detected only in the lungs of B2KO mice under HSD. On the other hand, metabolic studies showed that sodium urinary excretion was markedly reduced in B2KO compared with WT mice under ND. Finally, BQ123 (2 mg·kg(-1)) reduced by 50% the pressor response to L-NAME (2 mg·kg(-1)) in B2KO, but not WT mice under anaesthesia.

CONCLUSIONS AND IMPLICATIONS

Our results support the concept that functional B2 receptors oppose high salt-induced increments in MAP, which are corrected by an ETA receptor antagonist in this mouse model of experimental hypertension.

Racial differences in hypertension: implications for high blood pressure management

The racial disparity in hypertension and hypertension-related outcomes has been recognized for decades with African Americans with greater risks than Caucasians. Blood pressure levels have consistently been higher for African Americans with an earlier onset of hypertension. Although awareness and treatment levels of high blood pressure have been similar, racial differences in control rates are evident. The higher blood pressure levels for African Americans are associated with higher rates of stroke, end-stage renal disease and congestive heart failure. The reasons for the racial disparities in elevated blood pressure and hypertension-related outcomes risk remain unclear. However, the implications of the disparities of hypertension for prevention and clinical management are substantial, identifying African American men and women with excel hypertension risk and warranting interventions focused on these differences. In addition, focused research to identify the factors attributed to these disparities in risk burden is an essential need to address the evidence gaps.

Progression of coronary atherosclerosis in African-American patients

BACKGROUND

African-Americans with coronary artery disease (CAD) demonstrate worse clinical outcomes than Caucasians. While this is partly due to a lack of accessibility to established therapies, the mechanisms underlying this difference remain to be elucidated. We aimed to characterize the progression of coronary atherosclerosis in African-Americans with CAD.

METHODS

3,479 patients with CAD underwent serial intravascular ultrasound (IVUS) imaging to evaluate atheroma progression in 7 clinical trials of anti-atherosclerotic therapies. Risk factor control and atheroma progression were compared between African-Americans (n=170) and Caucasians (n=3,309).

RESULTS

African-Americans were more likely to be female (51.8% vs. 28.1%, P<0.001), have a higher body mass index (32.8±6.0 vs. 31.3±5.8 kg/m(2), P=0.002) and greater history of hypertension (85.9% vs. 78.8%, P=0.02), diabetes (41.8% vs. 30.6%, P=0.002) and stroke (12.9% vs. 3.0%, P<0.001). Despite a high use of anti-atherosclerotic medications (93% statin, 89% aspirin, 79% β-blocker, 52% ACE inhibitor), African-Americans demonstrated higher levels of LDL-C (2.4±0.7 vs. 2.2±0.7 mmol/L, P=0.006), CRP (2.9 vs. 2.0 mg/dL, P<0.001) and systolic blood pressure (133±15 vs. 129±13 mmHg, P<0.001) at follow-up. There was no significant difference in atheroma volume at baseline (189.0±82.2 vs. 191.6±83.3 mm(3), P=0.82) between two groups. Serial evaluation demonstrated a greater increase in atheroma volume in African-Americans (0.51±2.1 vs. -3.1±1.7 mm(3), P=0.01). This difference persisted with propensity matching accounting for differences in risk factor control (0.1±2.1 vs. -3.7±1.7 mm(3), P=0.02).

CONCLUSIONS

African-Americans with CAD achieve less optimal risk factor control and greater atheroma progression. These findings support the need for more intensive risk factor modification in African-Americans.

A review of the efficacy and tolerability of combination amlodipine/valsartan in non-white patients with hypertension

This article discusses racial/ethnic disparities in hypertension, with particular focus on non-white populations including blacks, Hispanics/Latinos, and Asians. Hypertension and its related morbidity and mortality affect a disproportionate number of black patients compared with white patients. Blacks, Hispanics/Latinos, and Asians have poor rates of hypertension awareness, treatment, and control. Given the high prevalence of comorbidities (e.g., obesity, diabetes, and metabolic syndrome) in these populations, renin–angiotensin–aldosterone system blockers are a good choice for foundation therapy. This review also discusses the importance of adherence and persistence with antihypertensive medication, which remain suboptimal in these non-white populations. Evidence suggests improvement with the use of single-pill combination therapy. Lastly, clinical trial data on the antihypertensive efficacy and safety of the combination of a dihydropyridine calcium channel blocker and an angiotensin receptor blocker, a widely utilized combination, in non-white populations are presented. PubMed was searched using the title/abstract key words (amlodipine AND valsartan AND [hypertension OR hypertensive] AND [black(s) OR African American(s) OR Hispanic(s) OR Latino(s) OR Mexican(s) OR Asian(s)]). In total, eight studies in patients with stage 1 or 2 hypertension were identified (n = 1,111 black, n = 389 Hispanic/Latino, and n = 3,094 Asian). Results showed that treatment with the combination of amlodipine plus valsartan is a reasonable choice for initial therapy or in patients who fail to respond to monotherapy. These drug classes have complementary mechanisms of action and, when used concomitantly, the magnitude of blood pressure lowering in these non-white populations is generally comparable with that seen in non-Hispanic white patients.

Difference in blood pressure response to ACE-Inhibitor monotherapy between black and white adults with arterial hypertension: a meta-analysis of 13 clinical trials

Background

Among African-Americans adults, arterial hypertension is both more prevalent and associated with more complications than among white adults. Hypertension is also epidemic among black adults in sub-Saharan Africa. The treatment of hypertension among black adults may be complicated by lesser response to certain classes of anti-hypertensive agents.

Methods

We systematically searched literature for clinical trials of ACE-inhibitors among hypertensive adults comparing blood pressure response between whites and blacks. Meta-analysis was performed to determine the difference in systolic and diastolic blood pressure response. Further analysis including meta-regressions, funnel plots, and one-study-removed analyses were performed to investigate possible sources of heterogeneity or bias.

Results

In a meta-analysis of 13 trials providing 17 different patient groups for evaluation, black race was associated with a lesser reduction in systolic (mean difference: 4.6 mmHg (95% CI 3.5-5.7)) and diastolic (mean difference: 2.8 mmHg (95% CI 2.2-3.5)) blood pressure response to ACE-inhibitors, with little heterogeneity. Meta-regression revealed only ACE-inhibitor dosage as a significant source of heterogeneity. There was little evidence of publication bias.

Conclusions

Black race is consistently associated with a clinically significant lesser reduction in both systolic and diastolic blood pressure to ACE-inhibitor therapy in clinical trials in the USA and Europe. In black adults requiring monotherapy for uncomplicated hypertension, drugs other than ACE-inhibitors may be preferred, though the proven benefits of ACE-inhibitors in some sub-groups and the large overlap of response between blacks and whites must be remembered. These data are particularly important for interpretation of clinical drug trials for hypertensive black adults in sub-Saharan Africa and for the development of treatment recommendations in this population.

Why do hypertensive patients of African ancestry respond better to calcium blockers and diuretics than to ACE inhibitors and β-adrenergic blockers? A systematic review

BACKGROUND

Clinicians are encouraged to take an individualized approach when treating hypertension in patients of African ancestry, but little is known about why the individual patient may respond well to calcium blockers and diuretics, but generally has an attenuated response to drugs inhibiting the renin-angiotensin system and to β-adrenergic blockers. Therefore, we systematically reviewed the factors associated with the differential drug response of patients of African ancestry to antihypertensive drug therapy.

METHODS

Using the methodology of the systematic reviews narrative synthesis approach, we sought for published or unpublished studies that could explain the differential clinical efficacy of antihypertensive drugs in patients of African ancestry. PUBMED, EMBASE, LILACS, African Index Medicus and the Food and Drug Administration and European Medicines Agency databases were searched without language restriction from their inception through June 2012.

RESULTS

We retrieved 3,763 papers, and included 72 reports that mainly considered the 4 major classes of antihypertensive drugs, calcium blockers, diuretics, drugs that interfere with the renin-angiotensin system and β-adrenergic blockers. Pharmacokinetics, plasma renin and genetic polymorphisms did not well predict the response of patients of African ancestry to antihypertensive drugs. An emerging view that low nitric oxide and high creatine kinase may explain individual responses to antihypertensive drugs unites previous observations, but currently clinical data are very limited.

CONCLUSION

Available data are inconclusive regarding why patients of African ancestry display the typical response to antihypertensive drugs. In lieu of biochemical or pharmacogenomic parameters, self-defined African ancestry seems the best available predictor of individual responses to antihypertensive drugs.

Effectiveness of cardiac resynchronization therapy with defibrillator in at-risk black and white cardiac patients

BACKGROUND

There are limited data regarding racial differences in response to cardiac resynchronization therapy with defibrillator (CRT-D).

METHODS

We assessed the effectiveness of CRT-D, as compared to implantable cardioverter defibrillator (ICD) therapy alone, in reducing the risk of heart failure (HF) or death and changes in cardiac volumes among 1638 (90%) white patients and 143 (8%) black patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT).

RESULTS

Enrolled black patients displayed a higher frequency of diabetes mellitus, treated hypertension, higher creatinine levels, and a lower distance walked in the baseline 6-minute walk test. Kaplan-Meier survival analysis showed that at 3 years of follow-up the cumulative probability of HF or death was higher among blacks (29%) as compared with whites (22%; P = 0.05). Both black and white patients experienced similar and pronounced reductions in cardiac volumes with CRT-D therapy (all P values for comparison between the two groups >0.10). Risk reduction conferred by CRT-D therapy as not significantly different between blacks and whites (hazard ratio = 0.78 and 0.60, respectively; P for the difference = 0.44). However, possibly due to sample size limitations the CRT-D versus ICD only adjusted risk for HF/death in blacks was not statistically significant.

CONCLUSIONS

Black patients in MADIT-CRT experienced increased risk of HF or death as compared with whites, but displayed a similar magnitude echocardiographic response to CRT-D. These findings suggest that cardiac resynchronization therapy may be an effective therapeutic modality in black patients. However, further studies are needed to assess the clinical response to CRT-D in this high-risk population.

Renal outcomes in hypertensive Black patients at high cardiovascular risk

The ACCOMPLISH trial (Avoiding Cardiovascular events through Combination therapy in Patients Living with Systolic Hypertension) was a 3-year multicenter, event-driven trial involving patients with high cardiovascular risk who were randomized in a double-blinded manner to benazepril plus either hydrochlorothiazide or amlodipine and titrated in parallel to reach recommended blood pressure goals. Of the 8125 participants in the United States, 1414 were of self-described Black ethnicity. The composite kidney disease end point, defined as a doubling in serum creatinine, end-stage renal disease, or death was not different between Black and non-Black patients, although the Blacks were significantly more likely to develop a greater than 50% increase in serum creatinine to a level above 2.6 mg/dl. We found important early differences in the estimated glomerular filtration rate (eGFR) due to acute hemodynamic effects, indicating that benazepril plus amlodipine was more effective in stabilizing eGFR compared to benazepril plus hydrochlorothiazide in non-Blacks. There was no difference in the mean eGFR loss in Blacks between therapies. Thus, benazepril coupled to amlodipine was a more effective antihypertensive treatment than when coupled to hydrochlorothiazide in non-Black patients to reduced kidney disease progression. Blacks have a modestly higher increased risk for more advanced increases in serum creatinine than non-Blacks.

Management of hypertension in high-risk ethnic minority with heart failure

Hypertension (HTN) is the most common co-morbidity in the world, and its sequelae, heart failure (HF) is one of most common causes of mortality and morbidity in the world. Current understanding of pathophysiology and management of HTN in HF is mainly based on studies, which have mainly included whites. Among racial groups, African-American adults have the highest rates (44%) of hypertension in the world and are more resistant to treatment. There is an emerging consensus on the significance of racial disparities in the pathophysiology and treatment options of hypertension and heart failure. However, African Americans had been underrepresented in all the trials until the initiation of the A-HEFT trial. Since the recognition of obstructive sleep apnea (OSA) as an important medical condition, large clinical trials have shown benefits of OSA treatment among patients with HTN and HF. This paper focuses on the pathophysiology, causes of secondary hypertension, and treatment of hypertension among African-American patients with heart failure. There is increasing need for randomized clinical trials testing innovative treatment options for African-American patients.

Impaired relaxation of cerebral arteries in the absence of elevated salt intake in normotensive congenic rats carrying the Dahl salt-sensitive renin gene

This study evaluated endothelium-dependent vascular relaxation in response to acetylcholine (ACh) in isolated middle cerebral arteries (MCA) from Dahl salt-sensitive (Dahl SS) rats and three different congenic strains that contain a portion of Brown Norway (BN) chromosome 13 introgressed onto the Dahl SS genetic background through marker-assisted breeding. Two of the congenic strains carry a 3.5-Mbp portion and a 2.6-Mbp portion of chromosome 13 that lie on opposite sides of the renin locus, while the third contains a 2.0-Mbp overlapping region that includes the BN renin allele. While maintained on a normal salt (0.4% NaCl) diet, MCAs from Dahl SS rats and the congenic strains retaining the Dahl SS renin allele failed to dilate in response to ACh, whereas MCAs from the congenic strain carrying the BN renin allele exhibited normal vascular relaxation. In congenic rats receiving the BN renin allele, vasodilator responses to ACh were eliminated by nitric oxide synthase inhibition with N(G)-nitro-l-arginine methyl ester, angiotensin-converting enzyme inhibition with captopril, and AT(1) receptor blockade with losartan. N(G)-nitro-l-arginine methyl ester-sensitive vasodilation in response to ACh was restored in MCAs of Dahl SS rats that received either a 3-day infusion of a subpressor dose of angiotensin II (3 ng·kg(-1)·min(-1) iv), or chronic treatment with the superoxide dismutase mimetic tempol (15 mg·kg(-1)·day(-1)). These findings indicate that the presence of the Dahl SS renin allele plays a crucial role in endothelial dysfunction present in the cerebral circulation of the Dahl SS rat, even in the absence of elevated dietary salt intake, and that introgression of the BN renin allele rescues endothelium-dependent vasodilator responses by restoring normal activation of the renin-angiotensin system.

Antihypertensive effects of double the maximum dose of valsartan in African-American patients with type 2 diabetes mellitus and albuminuria

OBJECTIVE

The blood pressure (BP)-lowering response to renin-angiotensin-aldosterone system blockade in hypertensive African-Americans is typically less than in whites. To determine whether higher than conventional doses of renin-angiotensin-aldosterone system blockade can improve BP reduction in African-American patients.

METHODS

Hypertensive patients with type 2 diabetes and albuminuria were enrolled: 110 African-Americans (BP = 150/87 mmHg, aged 57.5 +/- 11 years) and 281 non-African-Americans (BP = 151/89 mmHg, aged 57.7 +/- 11 years). All patients received valsartan 160 mg once daily in the morning for 4 weeks, following which patients were randomized to receive one of three valsartan doses: 160, 320 or 640 mg/day (2x, maximal recommended dose) for 26 weeks. If at week 6, target BP (<130/80 mmHg) was not achieved, then other add-on antihypertensives were allowed.

RESULTS

The predominant BP (DeltaSBP/DeltaDBP) reduction was observed within 4 weeks and was lesser in African-Americans (7.8 +/- 15/4.5 +/- 9 mmHg) than non-African-Americans (8.9 +/- 14/6.6 +/- 1 mmHg, P < 0.05). Greater reduction in urinary albumin excretion was observed with higher doses (320 or 640 mg); however, the responses were similar between African-Americans and non-African-Americans. Use of add-on antihypertensives was higher in African-American (56%) vs. non-African-American patients (36%) with a similar rate across the three valsartan doses. From week 4-26, reduction in BP was lesser (P < 0.05) for African-American than non-African-American patients at the160-mg dose but not with 320 and 640-mg doses.

CONCLUSION

In African-American patients, a lower BP reduction response was observed to conventional doses of valsartan than non-African-American patients, but at 640 mg, a higher response was observed in African-American patients than in non-African-American patients.

Protective effects of angiotensin-converting enzyme inhibitors in high-risk African American men with coronary heart disease

Angiotensin-converting enzyme (ACE) inhibitors have been extensively used for the treatment of patients with cardiovascular disease, but several concerns have been raised about their efficacy in African American (AA) patients with heart failure, hypertension, and left ventricular hypertrophy. In this study the authors assessed the effect of ACE inhibitors on total and cardiovascular mortality in high-risk AA patients with angiographically proven coronary artery disease (CAD). This was a retrospective analysis of 810 AA men who underwent diagnostic coronary angiography between 1995 and 2003. All patients had demonstrable CAD and had undergone a complete ischemic workup. Follow-up was from 3 to 10 years. ACE inhibitors were administered to 237 patients, while the remaining 537 patients were not taking ACE inhibitors. Patients taking ACE inhibitors had significantly more comorbidities (hypertension, diabetes, left ventricular hypertrophy, heart failure, severe CAD) at baseline, compared with patients not taking ACE inhibitors (P<.05 for all comorbidities). Despite the unfavorable baseline profile, patients taking ACE inhibitors had significantly lower mortality from CAD during follow-up than patients who were not taking ACE inhibitors (P=.006). Stroke mortality rates were similar in both groups. Cox regression analysis showed an 80% higher relative risk in patients not receiving ACE inhibitors. These data indicate a substantial benefit from ACE inhibitor therapy in high-risk AA patients with CAD.

How to treat hypertension in blacks: review of the evidence

Presentation, response to therapy, and clinical outcome differ according to race for patients with hypertension. Black patients have a higher prevalence and earlier onset of hypertension than other ethnic groups, with poorer prognosis than white patients. Blacks are more likely to be salt-sensitive, and to have a low plasma renin activity than are whites. They are at much greater risk of developing cardiovascular and renal complications. Despite many advances in the understanding and treatment of cardiovascular diseases, black patients continue to have increased morbidity and mortality from the end-organ complications of hypertension. The explanations for these observations remain incompletely understood, but genetic differences, added to socio-economic and environmental factors, have been proposed to explain this disparity. The first therapeutic approach is to decrease salt and increase potassium intakes. Diuretics (thiazides and potassium-sparing agents) and calcium channel blockers constitute the first antihypertensive drug choices. The angiotensin-converting-enzyme inhibitors, the angiotensin II receptor blockers and beta-blockers appear to be less effective in blacks with regard to uncomplicated hypertension, especially in older people, but addition of a small dose of diuretic improves their efficacy. These combinations are preferred among patients with chronic kidney disease or heart failure. The goal for blood pressure target is the same in blacks as it is in whites, being a blood pressure of less than 140/90 mmHg in uncomplicated hypertension and less than 130/80 mmHg in patients with diabetes mellitus or chronic kidney disease.

A role for single-pill triple therapy in hypertension

Hypertension remains the most prevalent chronic disease in the world, and its adequate treatment results in predictable reductions in cardiovascular morbidity and mortality. However, most hypertensive subjects do not achieve goal blood pressure despite availability of multiple antihypertensive agents with various pharmacological mechanisms of action and relatively few side effects. We review the reasons for low hypertension control rates, including factors that affect patients' adherence to therapy, number of agents required to achieve goal blood pressure, pathophysiology-based selection of therapy and diagnosis of resistant hypertension. Within this framework, we discuss the possible impact of a single-pill, triple-therapy combination with an antagonist of the renin—angiotensin system, a calcium-channel blocker and a diuretic. We focus on possible differential diagnostic implications in terms of refractoriness to treatment, and therapeutic implications in terms of successful blood pressure control. We conclude that a single-pill, triple-therapy combination may improve control of hypertension by enhancing compliance, by achieving blood pressure goal rapidly and by reducing physician inertia in prescribing adequate antihypertensive therapy. We also suggest that such a combination may lead to improved accuracy in diagnosing resistant hypertension in general practice, avoiding unnecessary further workup and referrals to hypertension specialists.

Blood pressure lowering efficacy of angiotensin converting enzyme (ACE) inhibitors for primary hypertension

BACKGROUND

ACE inhibitors are widely prescribed for hypertension so it is essential to determine and compare their effects on blood pressure (BP), heart rate and withdrawals due to adverse effects (WDAE).

OBJECTIVES

To quantify the dose-related systolic and/or diastolic BP lowering efficacy of ACE inhibitors versus placebo in the treatment of primary hypertension.

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library 2007, Issue 1), MEDLINE (1966 to February 2007), EMBASE (1988 to February 2007) and reference lists of articles.

SELECTION CRITERIA

Double-blind, randomized, controlled trials evaluating the BP lowering efficacy of fixed-dose monotherapy with an ACE inhibitor compared with placebo for a duration of 3 to 12 weeks in patients with primary hypertension.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the risk of bias and extracted data. Study authors were contacted for additional information. WDAE information was collected from the trials.

MAIN RESULTS

Ninety two trials evaluated the dose-related trough BP lowering efficacy of 14 different ACE inhibitors in 12 954 participants with a baseline BP of 157/101 mm Hg. The data do not suggest that any one ACE inhibitor is better or worse at lowering BP. A dose of 1/8 or 1/4 of the manufacturer's maximum recommended daily dose (Max) achieved a BP lowering effect that was 60 to 70% of the BP lowering effect of Max. A dose of 1/2 Max achieved a BP lowering effect that was 90% of Max. ACE inhibitor doses above Max did not significantly lower BP more than Max. Combining the effects of 1/2 Max and higher doses gives an estimate of the average trough BP lowering efficacy for ACE inhibitors as a class of drugs of -8 mm Hg for SBP and -5 mm Hg for DBP. ACE inhibitors reduced BP measured 1 to 12 hours after the dose by about 11/6 mm Hg.

AUTHORS' CONCLUSIONS

There are no clinically meaningful BP lowering differences between different ACE inhibitors. The BP lowering effect of ACE inhibitors is modest; the magnitude of trough BP lowering at one-half the manufacturers' maximum recommended dose and above is -8/-5 mm Hg. Furthermore, 60 to 70% of this trough BP lowering effect occurs with recommended starting doses. The review did not provide a good estimate of the incidence of harms associated with ACE inhibitors because of the short duration of the trials and the lack of reporting of adverse effects in many of the trials.

Racial analysis of patients with myocardial infarction complicated by heart failure and/or left ventricular dysfunction treated with valsartan, captopril, or both

OBJECTIVES

African Americans have a high incidence of heart failure (HF). Limited retrospective observational subgroup analyses of patients with left ventricular systolic dysfunction (LVSD) suggest marginal benefit of angiotensin-converting enzyme inhibitors in the prevention of HF hospitalizations or total mortality in African Americans.

BACKGROUND

Very few data exist concerning the effectiveness of angiotensin receptor blockers in this population.

METHODS

Baseline characteristics, treatments, and outcomes of patients from the U.S. (3,390 white and 340 African-American patients) in the VALIANT (VALsartan In Acute myocardial iNfarcTion) trial were compared. This trial included patients with an acute myocardial infarction (MI) after initial stabilization and documented LVSD and/or HF. Patients were randomly assigned to receive treatment with valsartan, captopril, or the combination; follow-up continued for up to 3 years (median 24.7 months).

RESULTS

African Americans had more coronary risk factors, more markers of poor outcome after MI, and were less likely to be revascularized when compared with white patients. After adjusting for treatment assignment, baseline characteristics, and post-infarction parameters, no difference was found in the 3-year rate of all-cause mortality, cardiovascular mortality, rehospitalization for HF, recurrent MI, or stroke between the 2 groups.

CONCLUSIONS

African Americans sustaining an acute MI with LVSD and/or HF had similar clinical outcomes compared with white Americans. Valsartan, captopril, or the combination had comparable effects on cardiovascular morbidity and mortality in African Americans and white Americans.

Meta-analysis comparing reported frequency of atrial fibrillation after acute coronary syndromes in Asians versus whites

The development of atrial fibrillation (AF) in cardiac patients is multifactorial, including not well defined genetic factors. To determine if Asian ethnicity is associated with the development of AF in patients with coronary disease, a meta-analysis was conducted of patient-level data from 7 prospective randomized clinical trials that prospectively collected information on the development of AF: 3 trials in patients with ST-elevation myocardial infarction (Global Use of Strategies to Open Occluded Coronary Arteries [GUSTO] I, GUSTO III, and GUSTO V), 3 trials in patients with non-ST-elevation acute coronary syndromes (Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy [PURSUIT], Integrilin to Minimize Platelet Aggregation and Coronary Thrombosis-II [IMPACT II], and Platelet IIb/IIIa Antagonist for the Reduction of Acute Coronary Syndrome Events in a Global Organization Network [PARAGON A]), and 1 trial in patients with both conditions (GUSTO IIb). A total of 94,785 patients were identified (93,050 white, 1,735 Asian). At baseline, Asian patients were younger; had lower body mass indexes; had a lower prevalence of female gender, previous angioplasty, and previous coronary artery bypass grafting; and had a greater prevalence of diabetes compared with white patients. The development of AF was lower in Asian than in white patients (4.7% vs 7.6%, p <0.001), while rates of ventricular tachycardia and fibrillation were similar in the 2 groups. In multivariate logistic regression analysis, Asian ethnicity was associated with significantly lower rates of AF (odds ratio 0.65, 95% confidence interval 0.50 to 0.84, p = 0.001) compared with white ethnicity. In conclusion, similar to previous studies showing a lower incidence of AF in non-Caucasian populations, Asians experiencing acute ischemic syndromes have a significantly lower frequency of AF compared with whites. Further study is needed to investigate the mechanisms and potential genetic underpinnings behind this association.

Bradykinin type 2 receptor BE1 genotype influences bradykinin-dependent vasodilation during angiotensin-converting enzyme inhibition

To test the hypothesis that the bradykinin receptor 2 (BDKRB2) BE1+9/-9 polymorphism affects vascular responses to bradykinin, we measured the effect of intra-arterial bradykinin on forearm blood flow and tissue-type plasminogen activator (t-PA) release in 89 normotensive, nonsmoking, white American subjects in whom degradation of bradykinin was blocked by enalaprilat. BE1 genotype frequencies were +9/+9:+9/-9:-9/-9=19:42:28. BE1 genotype was associated with systolic blood pressure (121.4+/-2.8, 113.8+/-1.8, and 110.6+/-1.8 mm Hg in +9/+9, +9/-9, and -9/-9 groups, respectively; P=0.007). In the absence of enalaprilat, bradykinin-stimulated forearm blood flow, forearm vascular resistance, and net t-PA release were similar among genotype groups. Enalaprilat increased basal forearm blood flow (P=0.002) and decreased basal forearm vascular resistance (P=0.01) without affecting blood pressure. Enalaprilat enhanced the effect of bradykinin on forearm blood flow, forearm vascular resistance, and t-PA release (all P<0.001). During enalaprilat, forearm blood flow was significantly lower and forearm vascular resistance was higher in response to bradykinin in the +9/+9 compared with +9/-9 and -9/-9 genotype groups (P=0.04 for both). t-PA release tended to be decreased in response to bradykinin in the +9/+9 group (P=0.08). When analyzed separately by gender, BE1 genotype was associated with bradykinin-stimulated t-PA release in angiotensin-converting enzyme inhibitor-treated men but not women (P=0.02 and P=0.77, respectively), after controlling for body mass index. There was no effect of BE1 genotype on responses to the bradykinin type 2 receptor-independent vasodilator methacholine during enalaprilat. In conclusion, the BDKRB2 BE1 polymorphism influences bradykinin type 2 receptor-mediated vasodilation during angiotensin-converting enzyme inhibition.

WITHDRAWN: Effect of antihypertensive drugs on mortality, morbidity and blood pressure in blacks

BACKGROUND

Black people have a greater prevalence of elevated blood pressure leading to excess morbidity and mortality.

OBJECTIVES

To systematically review the effects of different antihypertensive drugs on mortality, morbidity and blood pressure black adults with elevated blood pressure.

SEARCH STRATEGY

Medline, Embase, LILACS, African Index Medicus, the Cochrane Library November 2003; Pubmed September 2003 to March 2004. Searches were conducted without language restriction.

SELECTION CRITERIA

Randomised controlled trials of drugs versus placebo (blood pressure outcomes) or versus placebo or other drugs (morbidity and mortality outcomes).

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data unblinded. Disagreements were resolved by discussion. Authors were contacted twice to obtain missing information.

MAIN RESULTS

Full reports or abstracts from more than 2900 references of papers yielded 30 trials considering 53 interventions with 8 classes of antihypertensive drugs in 20,006 black patients from Africa, the Caribbean, and the United States of America, aged 18 to >80 years. In one large trial the main morbidity and mortality outcomes did not differ significantly between initial treatment drug classes when drugs were added to reach goal blood pressures. However, the comparison ACE Inhibitors vs diuretic favoured the diuretic for stroke 1.40 [1.17 to 1.68]; combined CHD 1.15 [1.02 to 1.30] and combined CVD 1.19 [1.09 to 1.30] and the comparison alpha blocker vs diuretic favoured the diuretic for combined CVD 1.40 [1.25 to 1.57]. In addition, all comparisons for heart failure favoured diuretic (1.47 [1.24 to 1.74] vs calcium blocker; 1.32 [1.11 to 1.58] vs ACE Inhibitor; and 2.18 [1.73 to 2.74] vs alpha blocker. The results also showed a greater occurrence of diabetes with diuretics. No significant differences were detected between placebo and beta adrenergic blockers in the reduction of systolic blood pressure (weighted mean difference [95% CI], -3.52 [-7.50 to 0.46] mm Hg). In addition, ACE inhibitors did not significantly differ from placebo in achievement of goal diastolic blood pressure (risk difference [95% CI], 5% [-10% to 21%]). Calcium blockers, diuretics, centrally acting agents, alpha adrenergic blockers and angiotensin II antagonists were all more effective than placebo in reducing blood pressure in the pooled analyses. Only calcium blockers remained effective in all prespecified subgroups, including baseline diastolic blood pressure >109 mm Hg.

AUTHORS' CONCLUSIONS

When first-line drugs from different classes are compared in the treatment of black people, there is no evidence of differential effects on most mortality and morbidity outcomes. Those morbidity differences that were found favoured diuretics. Drugs differ in their ability to reduce blood pressure in black people. Calcium blockers were the only drug class that reduced blood pressure in all subgroups of black people including those with severe hypertension. Beta-blockers, angiotensin receptor blocker, alpha blockers and ACE Inhibitors were least good at reducing blood pressure in black adults.

Factors influencing blood pressure response to trandolapril add-on therapy in patients taking verapamil SR (from the International Verapamil SR/Trandolapril [INVEST] Study)

Factors such as age and race/ethnicity might influence blood pressure (BP) response to drugs. Therapeutic response to the angiotensin-converting enzyme inhibitor trandolapril used as add-on therapy to stable calcium channel blocker therapy with verapamil sustained release 240 mg was addressed in a racially/ethnically diverse group of 1,832 hypertensive patients with coronary artery disease. Furthermore, the association with a polymorphism (1166A-->C) in the angiotensin II type 1 receptor gene (AGTR1) was tested. BP response was compared between groups using analysis of covariance after adjustment for covariates associated with BP response. Genotyping was performed using polymerase chain reaction and pyrosequencing. Trandolapril decreased mean unadjusted systolic and diastolic BPs by -9.1 +/- 17.3 (SD) and -4.1 +/- 10.1 mm Hg, respectively. The percentage of patients with BP under control (<140/90 mm Hg) increased from 6.7% to 41.3% (p <0.0001). Adjusted BP response was significantly associated with age and baseline systolic and diastolic BP (p <0.0001). Whereas the decrease in systolic BP was more pronounced in younger patients, the opposite was observed for diastolic BP decrease. Diastolic BP response was also significantly associated with race. Specifically, the adjusted diastolic BP decrease was significantly smaller in Hispanics and blacks than whites (p = 0.0032 and p = 0.0069, respectively). However, Hispanics achieved a decrease in systolic BP and an increase in BP control similar to the other ethnic groups. There was no genetic association between AGTR1 1166A-->C genotype and BP response. In conclusion, trandolapril add-on therapy was effective in increasing BP control, with age and baseline BP associated with both systolic and diastolic BP response. Race was associated with diastolic BP response, although the difference is likely not to be clinically significant and AGTR1 genotype was not associated with BP response.

Angiotensin‐Converting Enzyme Inhibitors and Angiotensin Receptor Blockers in African‐American Patients With Hypertension

African-American patients with hypertension are less responsive to blockers of the renin-angiotensin system than white patients. The relative efficacy of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers and the extent of cross-resistance to these agents has not been studied. Fifty-one African-American patients with stage 1-2 hypertension were randomly assigned to enalapril or candesartan cilexetil for 8 weeks and then crossed over to the other treatment. Nonresponders to enalapril and candesartan used a combination of the two. Of the 51 patients randomized (average age 61.2+/-9 years, blood pressure 148/100 mm Hg, heart rate 74 bpm, and body weight 92.8 kg), 44 completed the study. At Week 8, systolic blood pressure (SBP) was reduced by 4.8 mm Hg with enalapril and by 4.7 mm Hg with candesartan (p=NS), and diastolic blood pressure (DBP) was reduced by 4.4 mm Hg and 5.6 mm Hg, respectively (p<0.04). Of these 44 patients, 11 (25%) responded to enalapril by SBP criteria and 19 (43%) by DBP criteria. Seven patients (16%) responded by both SBP and DBP criteria, and 21 patients (48%) were nonresponders. With candesartan, 13 patients (29%) responded by SBP criteria, 20 (45%) by DBP criteria and 12 (27%) by both SBP and DBP criteria (p<0.04, compared with enalapril). Only six patients (14%) responded to both enalapril and candesartan by both SBP and DBP criteria. Of the 18 nonresponders to either enalapril or candesartan, the combination of the two had minimal additional effect. Significant changes in plasma-renin activity and angiotensin II levels were noted only with the high dose of each drug. In this small group of patients, treatment with candesartan resulted in slightly higher response and control rates than enalapril, more than 40% of patients who responded to enalapril did not respond to candesartan and vice versa, and in nonresponders, a combination of candesartan and enalapril offered little additional antihypertensive effect.

Ethnic difference in the relationship between acute inflammation and serum ferritin in US adult males

This study examined the ethnic difference in the association between increased serum ferritin (SF) (>300 microg/l) and acute inflammation (AI) (C-reactive protein > or = 1.0 mg/dl) between black and white males aged > or = 20 years. Using data from the third National Health and Nutrition Examination Survey (NHANES III), we determined the risk for having elevated SF in black males (n=164) and white males (n=325) with AI present as well as black males (n=1731) and white males (n=2877) with AI absent. Black subjects with AI present were 1.71 times (95% CI 1.18-2.49), and 1.87 times (95% CI 1.46-2.40) more likely to have increased SF than AI absent blacks and AI present whites, respectively. Furthermore, with AI present, every increment of C-reactive protein, white blood cell count, serum albumin, lymphocyte count and platelet count was associated with higher odds of having elevations in SF in blacks than whites. Regardless of AI status, blacks were more likely to have elevations in SF than whites, and the prevalence of elevated SF was significantly higher in blacks than whites. This finding suggested that black males may respond to inflammation with a more aggressive rise in SF compared to white males. Future research is needed to investigate the underlying mechanisms.

BiDil (isosorbide dinitrate and hydralazine): a new fixed-dose combination of two older medications for the treatment of heart failure in black patients

BiDil is a new fixed-dose combination of 2 older medications, isosorbide dinitrate (ISDN) and hydralazine. ISDN is an organic nitrate that is biotransformed into nitric oxide, a potent vasodilator. Hydralazine is believed to have both vasodilatory properties specific to the arteries and antioxidant properties, which address both the biochemical alterations in the failing cardiovascular system as well as the issue of nitrate tolerance. A drug regimen combining an NO stimulator (ISDN) with an antioxidant (hydralazine) favorably influences the nitroso-redox balance. Retrospective analyses of previous heart failure (HF) clinical trials comparing the combination of ISDN and hydralazine with placebo and enalapril, respectively, demonstrated a benefit in the black population, setting the precedent for a race-based therapeutic study, the African-American Heart Failure Trial (A-HeFT). A-HeFT examined the use of BiDil added to standard HF therapy in blacks with New York Heart Association functional class III and IV HF. BiDil demonstrated a 43% reduction in mortality when compared with placebo. As a result, current evidence-based treatment guidelines recommend that the addition of ISDN and hydralazine in black patients with moderate to severe HF optimized on standard therapy be considered. BiDil is currently indicated for the treatment of HF as an adjunct to standard therapy in black patients. The use of BiDil for black patients with mild disease or in nonblack patients with HF has not been studied. Future clinical trials involving an ethnically and clinically diverse population of patients would further define the role of combined ISDN and hydralazine in the treatment of HF.

Fixed combination isosorbide dinitrate–hydralazine for nitric-oxide-enhancing therapy in heart failure

The major advances in our understanding and management of heart failure (HF) in recent decades have not fully benefited all segments of our population. HF still represents a growing epidemic, especially for African-Americans, in whom the burden of HF is even greater. The recently reported beneficial effects of the fixed combination of isosorbide dinitrate and hydralazine (ISDN+HYD) in the African-American Heart Failure Trial (A-HeFT), has led to both the FDA approval of this agent and its endorsement by the latest HF guidelines. The properties of ISDN+HYD are well known as its components are mature agents, readily available in generic formulations that have been used for decades in other indications. However, fixed-dose ISDN+HYD represents the first drug to undergo targeted clinical development and to be approved for use in a specific ethnic group. As such, A-HeFT and the approval of ISDN+HYD represent landmark events that merit further scrutiny.

Randomized, Double-Blind, Crossover Comparison of Amlodipine and Valsartan in African-Americans with Hypertension Using 24-Hour Ambulatory Blood Pressure Monitoring

STUDY OBJECTIVE

To compare the efficacy of amlodipine and valsartan in African-American patients with hypertension using ambulatory blood pressure monitoring (ABPM).

DESIGN

Prospective, randomized, double-blind, crossover comparison study.

SETTING

University-affiliated cardiac center clinic.

PATIENTS

Twenty African-Americans (12 men, 8 women), with a history of uncomplicated hypertension (blood pressure > 140/90 mm Hg).

INTERVENTION

Patients were randomized to receive amlodipine 5 or 10 mg/day or valsartan 80 or 160 mg/day for 8-10 weeks, depending on response. Dosages were titrated to achieve a blood pressure of 140/90 mm Hg or below. For patients whose blood pressures were not controlled, hydrochlorothiazide 12.5 mg/day was added to their regimens. Patients then underwent 24-hour ABPM. After an intervening washout period during which baseline blood pressure was reestablished, patients received the other treatment.

MEASUREMENTS AND MAIN RESULTS

Mean +/- SD baseline blood pressure before the two ABPM periods were 155 +/- 12/100 +/- 8 mm Hg and 156 +/- 11/101 +/- 9 mm Hg, respectively. Fifteen (75%) patients achieved goal blood pressure with amlodipine and 14 (70%) with valsartan (p=0.62). Final daily dosages were as follows: amlodipine 5 mg in nine patients, 10 mg in five patients, and 10 mg plus hydrochlorothiazide in six patients; valsartan 80 mg in nine patients, 160 mg in four patients, and 160 mg plus hydrochlorothiazide in seven patients. Ambulatory blood pressure monitoring was not completed in three patients due to adverse effects: headache and dizziness (one patient each, amlodipine and valsartan) and hyperkalemia (one patient, valsartan). Four patients (20%) in each treatment group had drug-related adverse effects. Results of ABPM including averages for 24-hour, daytime, nighttime, first 4 hours, and last 8 hours, and trough:peak ratios were not significantly different between the amlodipine- and valsartan-based treatments.

CONCLUSION

Based on both clinic blood pressure measurements and ABPM data, amlodipine and valsartan produced similar reductions in blood pressure in African-American patients with uncomplicated hypertension.

Racial differences in outcome and treatment effect in congestive heart failure

BACKGROUND

In congestive heart failure (CHF), it is unknown whether race affects mortality and whether the effect of treatments differs by race.

METHODS

This study was a post hoc analysis of data from the DIG study that evaluated the effect of digoxin on morbidity and mortality in CHF.

RESULTS

Investigators followed 897 black and 6660 white participants for a mean of 37 months. Compared with whites, blacks were younger (60 +/- 13 vs 65 +/- 11 years). Total mortality was 34.2% in blacks and 33.6% in whites; hospitalization for worsening CHF occurred in 39% of blacks and 28% of whites. Cox regressions with race as the only covariate showed no effect of race on risk for death (relative risk = 1.04, 95% CI 0.93-1.18, P = .49) but an increase in CHF hospitalization in blacks (relative risk = 1.52, 95% CI 1.35-1.70, P = .0001). Multivariate Cox regression showed no difference by race in risk for death or death/hospitalization for CHF and no difference in the effect of digoxin on either end point.

CONCLUSION

Race is not an independent predictor of mortality in CHF. The effect of digoxin on morbidity and mortality in CHF does not differ in blacks and whites.

Dietary Approaches to Stop Hypertension (DASH) intervention reduces blood pressure among hypertensive African American patients in a neighborhood health care center

The purpose of this study was to pilot-test DASH-Dinner with Your Nutritionist, a university-neighborhood health care center intervention to promote the Dietary Approaches to Stop Hypertension (DASH) diet. Study participants were low-income African American adults (N = 82) with poorly controlled blood pressure. Six groups, each consisting of 12 to 15 participants taking antihypertensive medications, met for 1 to 2 hours per week for 8 weeks. The intervention followed constructs of Social Cognitive Theory and featured dinners based on the DASH diet plan. Blood pressure was significantly lowered (P < .05) among participants who missed no more than 2 of 8 sessions. Extension of the DASH-Dinner model could improve blood pressure control among low-income hypertensive African Americans and reduce health disparities.

Therapeutic considerations in the African-American patient with hypertension: considerations with calcium channel blocker therapy

African Americans have a higher prevalence, earlier onset, and more rapid progression of hypertensive end-organ disease, as well as excessive hypertensive mortality compared with other racial/ethnic groups. Most differences in hypertension and pressure-related complications between African Americans and whites appear to be quantitative and not qualitative. Improving the diagnosis, treatment, and control of hypertension in this highly vulnerable population is a major health care goal for the new millennium. In this regard the dietary pattern to be promoted for reduction of hypertension risk in African Americans is one of increased consumption of dairy products, fruit, and vegetables as well as a continued emphasis on decreased Na+ intake. When pharmacologic therapy is considered, multi-drug approaches are generally required, with diuretics, angiotensin-converting enzyme inhibitors (or angiotensin receptor blockers), and calcium channel blocker therapy as oft-selected components of most such treatment regimens.

Valsartan in Chronic Heart Failure

OBJECTIVE:

To evaluate the evidence for valsartan in the treatment of heart failure and determine its need for formulary inclusion.

DATA SOURCES:

OVID and PubMed databases were searched (1983–June 2004) using the key words angiotensin-receptor blocker, heart failure, valsartan, Diovan, and angiotensin-converting enzyme inhibitor. Only English-language literature was selected.

STUDY SELECTION AND DATA EXTRACTION:

Pharmacology and pharmacokinetic evaluations for valsartan were selected. Prospective, randomized clinical trials investigating the use of valsartan and other angiotensin-receptor blockers (ARBs) in chronic heart failure were evaluated.

DATA SYNTHESIS:

Valsartan, a selective antagonist for angiotensin receptor subtype 1, is the first ARB to be approved for use in chronic heart failure. Clinical trial data support valsartan as an alternative to angiotensin-converting enzyme (ACE) inhibitors in ACE inhibitor—intolerant patients with chronic heart failure. Valsartan is generally well tolerated, with renal impairment, elevated serum creatinine and potassium levels, and dizziness being the most common adverse effects; consequently, patients experiencing those adverse events while taking ACE inhibitors are likely to experience them with valsartan. Although further study is needed, differences in effectiveness among races may exist with use of valsartan; however, at this time, valsartan is recommended as an alternative to ACE inhibitors regardless of race. Candesartan and losartan have been studied in similar settings. Candesartan's data support its use in heart failure; however, losartan's data have been less consistent.

CONCLUSIONS:

Valsartan is a safe and effective alternative for heart failure patients intolerant of ACE inhibitors. Valsartan has not been shown to be safe and effective when used in combination with ACE inhibitors.

Will tomorrow's medicines work for everyone?

Throughout much of the world, 'race' and 'ethnicity' are key determinants of health. For example, African Americans have, by some estimates, a twofold higher incidence of fatal heart attacks and a 10% higher incidence of cancer than European Americans, and South Asian- or Caribbean-born British are approximately 3.5 times as likely to die as a direct result of diabetes than are British of European ancestry. The health care that people receive also depends on 'race' and 'ethnicity'. African Americans are less likely to receive cancer-screening services and more likely to have late-stage cancer when diagnosed than European Americans. Health disparities such as these are one of the greatest social injustices in the developed world and one of the most important scientific and political challenges.