Blood Pressure Outcomes in Patients Receiving Angiotensin II Receptor Blockers in Primary Care: A Comparative Effectiveness Analysis From Electronic Medical Record Data

Association between serum 25-hydroxyvitamin D and the effects of Angiotensin II receptor blocker on renal function among African Americans: A post hoc analysis of a randomized placebo-controlled trial

We tested the hypothesis that vitamin D status may modify the effect of Angiotensin II receptor blocker (ARB) on renal function among African Americans. Sixty-four participants were included in this ancillary study from a randomized, double-blind, placebo-controlled, crossover trial among normotensive African Americans to test the effect of ARB on stress response of blood pressure and renal sodium handling. The participants were randomly assigned to receive either ARB or placebo for one week, washed out for one week and then cross-overed to receive the other intervention for one week. On the final day of each intervention, the participant underwent a mental stress test. Baseline serum 25-hydroxyvitamin D [25(OH)D] level was measured in this ancillary study. Sixty-four participants were included, aged 26.5 ± 10.2 years and 47% were female. Among the participants with the serum 25(OH)D concentrations in the low tertile, ARB treatment was associated with 2.58 mg/dL higher blood urea nitrogen (BUN) (P < .001) and was not associated with serum creatinine (SCr) or estimated glomerular filtration rate (eGFR) (Ps > .05). Among the participants in the high 25(OH)D tertile, ARB was associated with 1.59 mg/dL lower BUN (P < .001), 0.08 mg/dL lower SCr (P = .001), and 8.59 mL/min/1.73 m² higher eGFR (P = .001). The interactions between vitamin D and ARB on renal function were more significant during stress and recovery than at rest. The effects of ARB treatment on renal function are modified by the vitamin D status among African Americans. ARB may improve renal function only among the ones with optimal vitamin D status.

Angiotensin II and the Natriuretic and Blood Pressure Response to Mental Stress in African Americans

Objective

To test the hypothesis that Angiotensin II (Ang II) is a contributing factor to the response pattern in African Americans (AAs) who retain rather than excrete sodium during mental stress.

Design/Study Participants

Double-blind, randomized, cross-over trial of 87 healthy AAs aged 18 to 50 years.

Interventions

The study participants received either a placebo or irbesartan, (150 mg PO), an Ang II receptor antagonist, for seven days prior to stress testing. Urinary sodium excretion (UNaV) and systolic blood pressure (SBP) were collected prior to and throughout a mental stress protocol (rest and stress period).

Setting

A southeastern university.

Main Outcome Measures

Ang II, SBP, and sodium retention.

Results

During the placebo condition, 62 participants showed the expected increase in UNaV (excreters) while 25 participants reduced UNaV during stress (retainers). Irbesartan retainers demonstrated a reversal in the direction of their natriuretic response, now increasing UNaV in response to stress (∆ UNaV of -.094 mmol/min with placebo vs .052 mmol/min on irbesartan; P<.001). In excreters, irbesartan reduced SBP levels during both rest (-2.36 mm Hg; P=.03) and stress (-4.59;P<.0001), and an even more pronounced reduction in SBP was demonstrated by retainers on treatment during both rest (-4.29 mm Hg; P=.03) and stress (-6.12; P<.001).

Conclusions

Ang II contributes to sodium retention in retainers. Furthermore, our findings indicate that suppression of Ang II has a beneficial effect on SBP during rest and stress in this population.

Effects of combining azilsartan medoxomil with amlodipine in patients with stage 2 hypertension

Objective

The aim of the study was to measure the effects on blood pressure (BP) of the angiotensin receptor blocker azilsartan medoxomil, in 40 and 80 mg doses, combined with 5 mg of the calcium channel blocker amlodipine and to compare these effects with placebo plus amlodipine 5 mg.

Methods

This was a randomized, controlled, double-blind study of 6 weeks’ duration in 566 patients with stage 2 hypertension. The primary endpoint was 24-h systolic BP by ambulatory monitoring.

Results

The mean age of the participants was 58 years; men and women were equally represented, and baseline 24-h BP (153–154/93 mmHg) and clinic BP (165–166/94–95 mmHg) were similar across the three treatment groups. After 6 weeks, 24-h BP decreased by 25/15 mmHg in both the azilsartan medoxomil/amlodipine 40/5 and 80/5 mg groups. These reductions were each greater than the 14/8 mmHg decrease with placebo plus amlodipine 5 mg (P≤0.001 for both comparisons). All treatments were well tolerated, and adverse events did not increase with the azilsartan medoxomil doses. Edema or fluid retention was less common in both combination groups (2.6 and 2.7%) than with placebo plus amlodipine (7.6%).

Conclusion

Coadministration of azilsartan medoxomil with amlodipine was well tolerated and led to meaningful additional BP reductions compared with placebo plus amlodipine.

Olmesartan in the treatment of hypertension in elderly patients: a review of the primary evidence

Hypertension, particularly systolic hypertension, is prevalent in the elderly and increases with advancing age, in part because of age-related endothelial dysfunction and increased arterial stiffness. There is strong evidence from randomized clinical trials that supports the use of antihypertensive treatment for effective and sustained blood pressure (BP) control in older patients to reduce the risk of vascular-related morbidity and mortality, particularly cerebrovascular accidents, including stroke. Furthermore, current evidence and guidelines suggest that all major classes of antihypertensive agents are equally effective in controlling BP and preventing cardiovascular events in older patients. Diuretics are commonly used in elderly patients, but recent outcomes data have raised doubt about their long-term benefits. Renin-angiotensin system inhibitors have a better tolerability profile than diuretics. Extensive clinical evidence has demonstrated the excellent efficacy and tolerability profile of olmesartan medoxomil (OM)--an angiotensin II receptor blocker AT1 receptor antagonist--including in elderly patients. Randomized and observational studies have shown that OM provides effective BP control across the 24 h dosing interval in the elderly. It also has a good tolerability profile, a pharmacokinetic profile unaffected by age and a low propensity for drug interactions. An additional factor is that OM once-daily regimens are simple and straightforward, which can be an important factor in maintaining adherence to therapy in elderly patients. This article provides an overview of the main recent clinical evidence supporting the use of OM-based therapy in elderly patients with hypertension.

Comparative effectiveness analysis of amlodipine/renin-angiotensin system blocker combinations

A comparative effectiveness analysis of antihypertensive therapy amlodipine (AML) and angiotensin receptor blocker (ARB) fixed- and loose-dose combinations (FDCs and LDCs) in achieving blood pressure (BP) reduction and Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC 7) goal attainment was made using retrospective electronic medical record (EMR) data. Treatment goal rates ranged from 35.0% for LDC AML/losartan to 45.7% for FDC AML/olmesartan (OM). FDC AML/OM achieved significantly greater reductions in systolic BP than FDC AML/benazepril (BEN), FDC AML/valsartan (VAL), and LDC AML/ARBs, respectively, and significantly greater reductions in diastolic BP than FDC AML/VAL and LDC therapy, respectively. Compared with patients treated with AML/OM, patients prescribed AML/VAL and LDC AML/ARB were significantly less likely to attain JNC 7 BP goal. Among subpopulations, AML/OM yielded higher rates of goal attainment among both African Americans and obese/overweight patients relative to AML/VAL and combined LDCs. Switchers from monotherapy with AML, OM, or VAL to AML/OM were significantly more likely to attain JNC 7 goals than those switching to AML/VAL or AML/BEN.

Comparison of the efficacy and safety of irbesartan and olmesartan in patients with hypertension (EARTH study)

Fifty-four patients were randomly divided into irbesartan and olmesartan groups. Blood pressure (BP) was significantly decreased in all patients at 12 weeks. In particular, BP in patients who initially received irbesartan showed significant reductions. The equality of variance of BP in the irbesartan group was significantly smaller than that in the olmesartan group at 12 weeks. Blood concentrations of adiponectin were significantly increased in the irbesartan group at 12 weeks. Log [pentraxin-3] in the irbesartan group were significantly decreased. In conclusion, the ability of irbesartan to reduce BP is comparable to that of olmesartan with equivalent safety.

Differential pharmacology and benefit/risk of azilsartan compared to other sartans

Azilsartan, an angiotensin II type 1 (AT₁) receptor blocker (ARB), was recently approved by regulatory authorities for treatment of hypertension and is the 8th ARB to join the clinical market. This article discusses the medical reasons for introducing a new AT₁ receptor blocker and reviews the experimental and clinical studies that have compared the functional properties of azilsartan to those of other ARBs. The main question addressed is: Does azilsartan have distinguishing features that should motivate choosing it over any of the other sartans for use in clinical practice? Based on studies conducted to date in hypertensive patients without serious comorbidities, azilsartan appears to be characterized by a superior ability to control 24-hour systolic blood pressure (BP) relative to other widely used ARBs including valsartan, olmesartan, and candesartan, and presumably others as well (eg, losartan). Compared to these other ARBs, azilsartan may increase the BP target control and response rate by an absolute value of 8%–10%. Greater antihypertensive effects of azilsartan might be due in part to its unusually potent and persistent ability to inhibit binding of angiotensin II to AT₁ receptors. Preclinical studies have indicated that azilsartan may also have potentially beneficial effects on cellular mechanisms of cardiometabolic disease and insulin sensitizing activity that could involve more than just blockade of AT₁ receptors and/or reduction in BP. However, the clinical relevance of these additional actions is unknown. Given that the general ability of antihypertensive drugs to protect against target organ damage is largely mediated by their ability to decrease BP, the enhanced antihypertensive effects of azilsartan should serve to justify clinical interest in this ARB relative to other molecules in the class that have a lower capacity to reduce BP.