Peripheral and Central Blood Pressure Responses of Combination Aliskiren/Hydrochlorothiazide and Amlodipine Monotherapy in African American Patients With Stage 2 Hypertension: The ATLAAST Trial

Central blood pressure for the management of hypertension: Is it a practical clinical tool in current practice?

Since noninvasive central blood pressure (BP) measuring devices are readily available, central BP has gained growing attention regarding its clinical application in the management of hypertension. The disagreement between central and peripheral BP has long been recognized. Some previous studies showed that noninvasive central BP may be better than the conventional brachial BP in association with target organ damages and long-term cardiovascular outcomes. Recent studies further suggest that the central BP strategy for confirming a diagnosis of hypertension may be more cost-effective than the conventional strategy, and guidance of hypertension management with central BP may result in less use of medications to achieve BP control. Despite the use of central BP being promising, more randomized controlled studies comparing central BP-guided therapeutic strategies with conventional care for cardiovascular events reduction are required because noninvasive central and brachial BP measures are conveniently available. In this brief review, the rationale supporting the utility of central BP in clinical practice and relating challenges are summarized.

The Role of Central Blood Pressure Monitoring in the Management of Hypertension

PURPOSE OF REVIEW

Central blood pressure is a novel predictor of cardiovascular risk that can be measured in the clinical setting using currently available technology. This paper will review current available methods of central blood pressure monitoring as well as its impact in cardiac and renal disease.

RECENT FINDINGS

Both aortic and carotid systolic blood pressure are independently associated with cardiovascular mortality and serious cardiac events. Furthermore, studies show that systolic aortic blood pressure has been shown to be superior predictor of cardiovascular as compared to brachial blood pressure. Inhibitors of the renin angiotensin axis may have a beneficial effect on central blood pressure; however, long term studies evaluating the impact of lowering central blood pressure on clinical outcomes are lacking. Central blood pressure is a good predictor of cardiovascular risk. As more studies emerge demonstrating the value of central blood pressure as a therapeutic target, it is possible that targeting central blood pressure may become an important part of the armamentarium to lower cardiovascular risk.

Renin Inhibition with Aliskiren: A Decade of Clinical Experience

The renin-angiotensin-aldosterone system (RAAS) plays a key role in the pathophysiology of arterial hypertension as well as in more complex mechanisms of cardiovascular and renal diseases. RAAS-blocking agents like angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers, have long been key components in the treatment of essential hypertension, heart failure, diabetic nephropathy, and chronic kidney disease, showing benefits well beyond blood pressure reduction. Renin blockade as the first step of the RAAS cascade finally became possible in 2007 with the approval of aliskiren, the first orally active direct renin inhibitor available for clinical use and the newest antihypertensive agent on the market. In the last decade, many clinical trials and meta-analyses have been conducted concerning the efficacy and safety of aliskiren in comparison to other antihypertensive agents, as well as the efficacy and potential clinical use of various combinations. Large trials with cardiovascular and renal endpoints attempted to show potential benefits of aliskiren beyond blood pressure lowering, as well as morbidity and mortality outcomes in specific populations such as diabetics, heart failure patients, and post-myocardial infarction individuals. The purpose of this review is to present the currently available data regarding established and future potential clinical uses of aliskiren.

Race-ethnicity on blood pressure control after ischemic stroke: a prospective cohort study

Disparities in health care access and socioeconomic status (SES) have been associated with racial-ethnic differences in blood pressure (BP) control. We examined post-ischemic stroke BP in a multiethnic cohort with good health care access. We included all hypertensive patients (n = 2972) from a randomized quality improvement trial on secondary stroke prevention, conducted in 14 Kaiser Permanente hospitals in Northern California from 2004-2006 (QUISP). Average age 73.2 ± 12.2 years; 52% female, 66% non-Hispanic white, 14% African-American, 11% Asian, 8% Hispanic, and 1% other. Demographics, diagnoses, health care utilization, BP measurements, and medications were obtained as part of routine care. We used random effects logistic regression models to examine race as a predictor of blood pressure control (<140/90 mm Hg) at 6 months post-discharge, adjusted for SES, age, gender, dementia, antihypertensive therapy, and attendance at follow-up visits. At 6 months, BP was controlled in 52.7% of blacks compared to 61.4% of whites (OR = 0.63, 95% CI, 0.48-0.82, P = .001). Black race remained independently associated with poorer BP control in adjusted analysis, although blacks were as likely to attend post-discharge visits, and more likely to be on any antihypertensive therapy than whites. Greater difficulty in controlling BP and lifestyle differences may account for this difference.

Arterial Stiffness in Treated Hypertensive Patients With White-Coat Hypertension

Arterial stiffness, assessed through pulse wave velocity (PWV), independently predicts cardiovascular outcomes. In untreated persons, white-coat hypertension (WCH) has been related to arterial stiffness, but data in treated patients with WCH are scarce. The authors aimed to determine a possible association between WCH and arterial stiffness in this population. Adult treated hypertensive patients underwent home blood pressure monitoring and PWV assessment. Variables associated with PWV in univariable analyses were entered into a multivariable linear regression model. The study included 121 patients, 33.9% men, median age 67.9 (interquartile range 18.4) years, 5.8% with diabetes, and 3.3% with a history of cardiovascular or cerebrovascular disease. In multivariable analysis, WCH in treated hypertensive patients remained a determinant of PWV: β=1.1 (95% confidence interval, 0.1-2.1 [P=.037]; adjusted R² 0.49). In conclusion, WCH is independently associated with arterial stiffness in treated hypertensive patients. Whether this high-risk association is offset by antihypertensive treatment should be further investigated.

Impact of Antihypertensive Agents on Central Systolic Blood Pressure and Augmentation Index: A Meta-Analysis

BACKGROUND

New evidence suggests that central systolic blood pressure (cSBP) and augmentation index (AI) are superior predictors of adverse cardiovascular outcomes compared to peripheral systolic BP (pSBP). We performed a meta-analysis assessing the impact of antihypertensives on cSBP and AI.

METHODS

PubMed, Cochrane Library, and CINAHL were searched until September 2014 to identify eligible articles. A DerSimonian and Laird random-effects model was used to calculate the weighted mean difference (WMD) and its 95% confidence interval (CI). Fifty-two and 58 studies incorporating 4,381 and 3,716 unique subjects were included for cSBP and AI analysis, respectively.

RESULTS

Overall, antihypertensives reduced pSBP more than cSBP (WMD 2.52 mm Hg, 95% CI 1.35 to 3.69; I (2) = 21.9%). β-Blockers (BBs) posed a significantly greater reduction in pSBP as compared to cSBP (WMD 5.19 mm Hg, 95% CI 3.21 to 7.18). α-Blockers, angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, calcium channel blockers, diuretics, renin-angiotensin aldosterone system inhibitors and nicorandil reduced cSBP and pSBP in a similar manner. The overall reduction in AI from baseline was 3.09% (95% CI 2.28 to 3.90; I (2) = 84.5%). A significant reduction in AI was seen with angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, calcium channel blockers, diuretics, renin-angiotensin aldosterone system inhibitors, BBs, α-blockers (ABs), nicorandil, and moxonidine reduced AI nonsignificantly.

CONCLUSIONS

BBs are not as beneficial as the other antihypertensives in reducing cSBP and AI.

Effects of aliskiren- and ramipril-based treatment on central aortic blood pressure in elderly with systolic hypertension: a substudy of AGELESS

BACKGROUND

Systolic hypertension is the most common form of hypertension in elderly patients. There is increasing evidence that measurement of central aortic pressure (CAP) better accounts for cardiovascular risk than brachial blood pressure (BP). The Aliskiren for GEriatric LowEring of SyStolic hypertension (AGELESS) study in elderly patients with systolic hypertension showed that aliskiren-based therapy provided greater reductions in peripheral BP than ramipril-based therapy over 12 and 36 weeks of treatment. Here, we present CAP results in a substudy of elderly patients from the AGELESS study.

METHODS

This was a post hoc analysis of a 36-week, randomized, double-blind, parallel-group, active-controlled, optional-titration study in patients ≥65 years of age with systolic BP ≥140 mmHg. Changes in both central and peripheral BP and pulse pressure (PP) and changes in systolic and PP amplification ratios from baseline to the week 36 end point with aliskiren-based versus ramipril-based therapy were analyzed.

RESULTS

Of the 901 patients randomized in the overall study, 154 patients (aliskiren, n=78; ramipril, n=76) had CAP data. Numerically comparable reductions were seen for central aortic systolic pressure (CASP) in aliskiren-based therapy (baseline: 143.7±15.0; week 36: -20.3±16.2) compared with ramipril-based therapy (baseline: 147.9±11.9; week 36: -20.7±14.6). However, for the change in central aortic diastolic pressure, the least squares mean between-treatment difference (-3.6 mmHg [95% confidence interval, -6.76, -0.43; P=0.0263]) was in favor of aliskiren, while the other changes were comparable between the two groups with a trend in favor of aliskiren for CASP as well (-2.6 mmHg [95% confidence interval, -7.38, 2.19; P=0.2855)]. Correlation coefficients for change from baseline between CASP and systolic BP and between central aortic pulse pressure and PP (r=0.8, P<0.0001) were highly significant.

CONCLUSION

Aliskiren-based therapy provides comparable reductions in CASP to ramipril-based therapy. Although the results did not reach statistical significance, these findings, when coupled with those of the main study, suggest that aliskiren may offer effective control of central BP in elderly patients with systolic hypertension and may be a good alternative to ramipril.

Aortic stiffness: pathophysiology, clinical implications, and approach to treatment

Aortic stiffness is a hallmark of aging, and classic cardiovascular risk factors play a role in accelerating this process. Current changes in medicine, which focus on preventive care, have led to a growing interest in noninvasive evaluation of aortic stiffness. Aortic stiffness has emerged as a good tool for further risk stratification because it has been linked to increased risk of atherosclerotic heart disease, myocardial infarction, heart failure, and stroke. This has led to the invention and validation of multiple methods to measure aortic stiffness. Pulse wave velocity is emerging as the gold standard for evaluation of aortic stiffness. This review focuses on the pathophysiology involved in aortic stiffness, methods available for evaluation of aortic stiffness, the importance of central pressure as a predictor of future cardiovascular events, and therapies that affect aortic stiffness.

Role of aliskiren on arterial stiffness and endothelial function in patients with primary hypertension

Arterial stiffness and endothelial dysfunction are important determinants of cardiovascular events in patients with arterial hypertension. There are few data regarding the role of aliskiren on the central hemodynamics and endothelial function in patients with uncontrolled arterial hypertension. The aim of this study was to assess the addition of aliskiren to other antihypertensive drug treatment for arterial stiffness and endothelial function. Thirty uncontrolled hypertensive patients (mean age, 60.4±12.2 years), without any other cardiovascular risk factors, were enrolled. Augmentation index (AIx) and carotid-femoral pulse wave velocity (cfPWV) by applanation tonometry and reactive hyperemia peripheral arterial tonometry (RH PAT) index using peripheral arterious tonometry at baseline and after 6 months of aliskiren titrated to 300 mg once a day was evaluated. The addition of aliskiren had no effect on values of central AIx (33.26±10.74% vs 28.86±10.74%; P=.36) but did significantly improve values of cfPWV (9.36±2.65 m/s vs 8.72±2.48 m/s; P=.04) and RH PAT index (1.64±0.57 vs 1.75±0.45; P=.05). In addition to improving systolic and diastolic blood pressure, the addition of aliskiren to concomitant antihypertensive drugs in uncontrolled hypertensive patients may be effective in improving aortic stiffness and endothelial function. These results encourage further studies to evaluate the use of aliskiren for cardiovascular prevention.

Aliskiren/amlodipine vs. aliskiren/hydrochlorothiazide in hypertension: indirect meta-analysis of trials comparing the two combinations vs. monotherapy

BACKGROUND

Aliskiren, a direct renin inhibitor, is effective for reducing blood pressure (BP) in patients with hypertension when combined with amlodipine or hydrochlorothiazide (HCTZ). However, the efficacy and tolerability of the 2 combinations are unclear. We performed a meta-analysis of randomized controlled trials of aliskiren/amlodpine and aliskiren/HCTZ for hypertension.

METHODS

The Cochrane Central Register of Controlled Trials, MEDLINE, Embase, and the Novartis clinical trial database were searched through December 2012 for reports of randomized controlled trials of aliskiren/amlodpine and aliskiren/HCTZ vs. monotherapy in patients with hypertension. The main outcome measures were reduction in systolic BP and diastolic BP from baseline and rates of therapeutic response and BP control. Tolerance of aliskiren/amlodipine and aliskiren/HCTZ was also analyzed. Outcomes were initially pooled by standard random-effects methods, producing a weighted mean difference (WMD) or risk ratio (RR) and 95% confidence intervals (CIs). The pooled estimates were then used for adjusted indirect comparisons.

RESULTS

We selected 19 reports of trials involving 13,614 participants. Aliskiren/amlodpine and aliskiren/HCTZ were more effective than monotherapy in controlling BP. Aliskiren/amlodipine was significantly more effective than aliskiren/HCTZ in reducing systolic BP (WMD = -3.36 mm Hg; 95% CI = -4.64 to 2.07 mm Hg) and diastolic BP (WMD = -3.49 mm Hg; 95% CI = -4.34 to 2.63 mm Hg). As compared with aliskiren/HCTZ, alikiren/amlodipine was associated with higher rate of therapeutic response (RR = 1.23; 95% CI = 1.14-1.33) and BP control (RR = 1.24; 95% CI = 1.11-1.39). Number of adverse events and withdrawals due to adverse events were similar with aliskiren/amlodipine and aliskiren/HCTZ.

CONCLUSIONS

BP control is better with aliskiren combined with amlodipine or HCTZ than with monotherapy, with aliskiren/amlodipine being more effective than aliskiren/HCTZ.

Meta-analysis of the comparative effects of different classes of antihypertensive agents on brachial and central systolic blood pressure, and augmentation index

AIMS

Brachial systolic blood pressure (bSBP) exceeds aortic pressure by a variable amount, and estimated central systolic blood pressure (cSBP) may be a better indicator of cardiovascular risk than bSBP. We undertook a systematic review and meta-analysis to compare the effect of single and multiple antihypertensive agents on bSBP, cSBP and augmentation index (AIx).

METHODS

A random effects meta-analysis was performed on 24 randomized controlled trials of antihypertensives with measurements of bSBP, cSBP and/or AIx. Separate analyses were performed for drug comparisons with or without placebo, and drug combinations.

RESULTS

In the placebo vs. drug meta-analysis, antihypertensive therapy reduced bSBP more than cSBP and there was no statistically significant evidence of heterogeneity by drug class, although the number of individual studies was small. In placebo-adjusted drug vs. drug comparison, treatment with β-blockers, omapatrilat and thiazide diuretics lowered cSBP significantly less than bSBP (i.e. central to brachial amplification decreased), whereas other monotherapies lowered cSBP and bSBP to similar extents. Sample sizes were too small and effect estimates insufficiently precise to allow firm conclusions to be made regarding comparisons between individual drug classes. Antihypertensive combinations that included β-blockers decreased central to brachial amplification. β-Blockers increased AIx, whereas all other antihypertensive agents reduced AIx to similar extents.

CONCLUSIONS

A reduction in central to brachial amplification by some classes of antihypertensive drug will result in lesser reductions in cSBP despite achievement of target bSBP. This effect could contribute to differences in outcomes in randomized clinical trials when β-blocker- and/or diuretic-based antihypertensive therapy are compared with other regimens.

Evaluating interventions to reduce central aortic pressure, arterial stiffness and morbidity--mortality

Arterial aging is associated with a progressive increase in aortic stiffening, which results in a rise in central aortic pressures. Traditionally, blood pressure (BP)-lowering therapy has been directed at brachial rather than central pressures. However, a key contemporary question is whether this strategy is optimal in reducing aortic pressure and aortic stiffness, and whether specific treatment strategies might be preferred to reduce the process of arterial aging. This review examines current evidence that BP-lowering treatments can differentially affect aortic pressure and stiffness parameters relative to brachial BP. There is now unequivocal evidence that different treatment regimens can differentially affect BP in the central aorta relative to brachial BP, and emerging evidence of BP-independent differential drug effects on arterial stiffness. A remaining challenge is to link any potentially favorable changes in aortic pressure and/or stiffness to improvements in morbidity and mortality over and above those expected from conventional BP lowering.

Aliskiren, amlodipine and hydrochlorothiazide triple combination for hypertension

Cardiovascular-related morbidity and mortality is linked to hypertension with proportional gains in cardiovascular risk factor reduction with the lowering of blood pressure. Clinical trial data has shown that attaining goal blood pressure requires, for most patients, at least two antihypertensive medications, with a significant proportion requiring regimens of three or more medications. Single-pill triple combinations have returned to the market following results of increased efficacy and adherence over dual- and mono-therapy. The combination of aliskiren, amlodipine and hydrochlorothiazide is a rational choice for combination therapy and recent studies suggest that it is safe and effective in lowering blood pressure in patients who fail dual combination therapy.