The Role of Angiotensin II Type 1 Receptor Antagonists in Elderly Patients with Hypertension

The renin-angiotensin system and cardiovascular autonomic control in aging

Aging is the greatest independent risk factor for developing hypertension and cardiovascular-related diseases including systolic hypertension, vascular disease, ischemic events, arrhythmias, and heart failure. Age-related cardiovascular risk is associated with dysfunction of peripheral organ systems, such as the heart and vasculature, as well as an imbalance in the autonomic nervous system characterized by increased sympathetic and decreased parasympathetic neurotransmission. Given the increasing prevalence of aged individuals worldwide, it is critical to better understand mechanisms contributing to impaired cardiovascular autonomic control in this population. In this regard, the renin-angiotensin system has emerged as an important hormonal modulator of cardiovascular function in aging, in part through modulation of autonomic pathways controlling sympathetic and parasympathetic outflow to cardiovascular end organs. This review will summarize the role of the RAS in cardiovascular autonomic control during aging, with a focus on current knowledge of angiotensin II versus angiotensin-(1-7) pathways in both rodent models and humans, pharmacological treatment strategies targeting the renin-angiotensin system, and unanswered questions for future research.

Development of L-Lysine Amino Acid-Based Co-Crystal of Telmisartan Using Crystal Engineering Approach to Improve Solubility, Dissolution, and Micrometric Properties

AIM

To develop a co-crytsal of Telmisartan for enhancing its solubility in water.

BACKGROUND

Intermolecular interaction happens in crystal packing; it utilizes and helps to understand the design of new solid with their respective chemical and physical properties called crystal engineering. It is a blueprint of molecular solids with specific chemical and physical properties through an understanding and handling of intermolecular interaction for increasing the solubility, in case of poor water-soluble drugs.

OBJECTIVES

The study was taken under consideration with an aim to generate and synthesize a cocrystal form of Telmisartan (TEL) with L-lysine to improve its water solubility, dissolution, and micrometric properties.

METHODS

Using dry grinding technique, solvent evaporation and cooling crystallization, the results revealed a generation of co-crystals with enhanced solubility by liquid drop grinding method. Hence, this process was further explored to investigate various formulations and process parameters that could significantly affect the crystal solubility, dissolution, and micrometric properties.

RESULTS

The solubility of TEL co-crystals was enhanced by L-lysine. Further, the optimized batch was subjected to its micrometric evaluation and physiochemical characterization like FT-IR, NMR, PXRD. The result of the micrometric evaluation showed better results as compared to standards. The dissolution studies also showed a better dissolution rate for TEL co-crystal tablets than TEL tablets formulation.

CONCLUSION

Co-crystals of TEL with L-lysine showed better solubility and dissolution rate.

Angiotensin-(1-7) Improves Integrated Cardiometabolic Function in Aged Mice

Angiotensin (Ang)-(1-7) is a beneficial renin–angiotensin system (RAS) hormone that elicits protective cardiometabolic effects in young animal models of hypertension, obesity, and metabolic syndrome. The impact of Ang-(1-7) on cardiovascular and metabolic outcomes during aging, however, remains unexplored. This study tested the hypothesis that Ang-(1-7) attenuates age-related elevations in blood pressure and insulin resistance in mice. Young adult (two-month-old) and aged (16-month-old) male C57BL/6J mice received Ang-(1-7) (400 ng/kg/min) or saline for six-weeks via a subcutaneous osmotic mini-pump. Arterial blood pressure and metabolic function indices (body composition, insulin sensitivity, and glucose tolerance) were measured at the end of treatment. Adipose and cardiac tissue masses and cardiac RAS, sympathetic and inflammatory marker gene expression were also measured. We found that chronic Ang-(1-7) treatment decreased systolic and mean blood pressure, with a similar trend for diastolic blood pressure. Ang-(1-7) also improved insulin sensitivity in aged mice to levels in young mice, without effects on glucose tolerance or body composition. The blood pressure–lowering effects of Ang-(1-7) in aged mice were associated with reduced sympathetic outflow to the heart. These findings suggest Ang-(1-7) may provide a novel pharmacological target to improve age-related cardiometabolic risk.

Impact of Hospitalization on Antihypertensive Pharmacotherapy among Older Persons

Background

Little is known about the impact of hospitalization on antihypertensive pharmacotherapy and blood pressure control in older persons.

Objectives

The aim of this study was to explore the impact of hospitalization on the management of hypertension and antihypertensive pharmacotherapy in a cohort of older patients with a documented diagnosis of hypertension.

Methods

A retrospective, cross-sectional medical record audit was conducted in a large Australian metropolitan teaching hospital. Patients aged 65 years or older, admitted between January 1st 2010 and December 31st 2010, and with a documented diagnosis of hypertension in their medical record were included in the study. Antihypertensive pharmacotherapy and blood pressure control was compared between admission and discharge. Factors associated with changes to antihypertensive pharmacotherapy were identified.

Results

Changes to antihypertensive pharmacotherapy occurred in 39.5 % (n = 135) of patients (n = 342). On discharge, the proportion of patients receiving antihypertensive pharmacotherapy (89.0 vs 85.3 %, p < 0.0001) and the mean number of antihypertensive agents per patient (1.7 ± 1.1 vs 1.5 ± 1.1, p < 0.0001) declined compared with admission. Adverse drug reactions [odds ratio (OR) = 5, 95 % confidence interval (CI): 2.80–9.34] were the main reason documented for antihypertensive pharmacotherapy changes. Patients admitted under the care of medical (OR = 0.3, 95 % CI: 0.17–0.70) or surgical (OR = 0.3, 95 % CI: 0.12–0.53) specialties were less likely to experience changes to their antihypertensive pharmacotherapy than those treated by gerontology or cardiology teams.

Conclusions

Hospitalization has a significant impact on antihypertensive pharmacotherapy. Two out of every five older persons on antihypertensive medications will experience changes to their regimens during admission to hospital with most changes in antihypertensive pharmacotherapy due to adverse drug reactions.

Effect of prazosin on diabetic nephropathy patients with positive α1-adrenergic receptor autoantibodies and refractory hypertension

To investigate the effect of prazosin on patients with diabetic nephropathy (DN), α1-adrenergic receptor (α1-R) autoantibodies and refractory hypertension, a total of 126 patients with DN and hypertension were recruited. The patients were divided into a refractory hypertension group, (n=76) and a non-refractory hypertension group (n=50). The epitope of the second extracellular loop of the α1-R (192–218) was synthesized and an enzyme-linked immunosorbent assay (ELISA) was performed to detect serum autoantibodies. In the group with DN-associated refractory hypertension, the positive rate of autoantibodies against the α1-R was 80.3% (n=61). The 61 patients who were positive for α1-R autoantibodies were randomly divided into a treatment group (n=31) and a control group (n=30). The patients were given drugs at the same dosage and administration, with the exception of prazosin, which was provided only to the patients in the treatment group [1 mg, three times a day (tid)] for a duration of six weeks. Subsequently, prazosin was added (1 mg, tid) to the therapeutic schedule of the patients in the control group and the α1-R autoantibody-negative group for another six weeks. The analysis was carried out on an intention-to-treat basis. The prazosin treatment resulted in significant improvements in hypertension in the treatment group (P<0.05), while there was no marked improvement in the control group. The total effective rate of hypertension improvement was 90.3% in the treatment group, which was higher compared with that of the control group (33.3%). In conclusion, α1-R autoantibodies may play an important role in the pathogenesis of DN with refractory hypertension. Prazosin was demonstrated to be effective and safe in the treatment of DN with refractory hypertension.

Clinical factors in patients with ischemic versus hemorrhagic stroke in East China

BACKGROUND

Stroke is one of the leading causes of mortality and morbidity of vascular diseases, and its incidence maintains at a high level around the world. In China, stroke has been a major public health problem. Because the pathogenesis of ischemic stroke is different from that of hemorrhagic stroke, their clinical factors would not be the same. Therefore to investigate the different effects of various effect factors on ischemic versus hemorrhagic stroke and then to enhance the prevention are crucial to decrease the incidence.

METHODS

A total of 692 patients, consisting of 540 ischemic stroke patients and 152 hemorrhagic stroke patients from East China, were included in this study. The related factors of stroke subtypes were collected and analyzed.

RESULTS

The factors significantly associated with ischemic stroke as opposed to hemorrhagic stroke were family history of stroke, obesity, atherosclerotic plaque of the common carotid artery, atrial fibrillation, hyperfibrinogenemia, transient ischemic attack (TIA), atherosclerotic plaque of the internal carotid artery, coronary heart, lower high-density lipoproteins (lower HDL), increasing age, diabetes mellitus, and gender (male) (P<0.05). Leukocytosis, hypertension and family history of hypertension were the significant factors associated with hemorrhagic stroke versus ischemic stroke. Smoking, drinking, kidney diseases and lower HDL-C were the significant factors contributing to ischemic stroke in man. Obesity, family history of hypertension, family history of stroke, hypercholesteremia and myocardial ischemia were the significant factors for females with ischemic stroke.

CONCLUSIONS

The most prominent factors for overall stroke in East China were hypertension, followed by higher pulse pressure and hypercholesteremia. The factors for ischemic and hemorrhagic stroke are not the same. Different effects of risk factors on stroke are found in male and female patients.

Detection of metals and metalloproteins in the plasma of stroke patients by mass spectrometry methods

Stroke is the leading cause of adult disability, worldwide. Metalloproteins and metals play key roles in epigenetic events in living organisms, including hypertension, the most important modifiable risk factor for stroke. Thus, metalloproteins may be important target biomarkers for disease diagnosis. The primary goal of this study was to assess metal containing proteins in blood plasma, detected by ICP-MS, followed by ESIMS for peptide/protein identification. We then compared the relative concentration differences between samples from patients with ischemic stroke, hemorrhagic stroke and stroke mimics. In 29 plasma samples (10 stroke mimics, 10 ischemic stroke and 9 hemorrhagic stroke patients) previously collected from patients who presented to the University of Cincinnati Emergency Department within 12 hours of symptom onset for a plasma banking project. For the metal associated protein study, Mg, Mn, Cu, Se concentrations were statistically different when compared between stroke mimics vs. ischemic stroke patients and ischemic stroke patients vs. hemorrhagic stroke patients. Pb concentrations were statistically different when compared between stroke mimics vs. ischemic stroke patients and Mo levels were statistically the same among the three groups. In addition, we also report concentration levels and preliminary correlation studies for total elemental analysis among the three sets of patients. This pilot study demonstrates that mass spectrometry methods may be highly valuable in detecting novel stroke biomarkers in blood plasma. Expanded studies are warranted to confirm these findings.

Italian guidelines for primary headaches: 2012 revised version

The first edition of the Italian diagnostic and therapeutic guidelines for primary headaches in adults was published in J Headache Pain 2(Suppl. 1):105–190 (2001). Ten years later, the guideline committee of the Italian Society for the Study of Headaches (SISC) decided it was time to update therapeutic guidelines. A literature search was carried out on Medline database, and all articles on primary headache treatments in English, German, French and Italian published from February 2001 to December 2011 were taken into account. Only randomized controlled trials (RCT) and meta-analyses were analysed for each drug. If RCT were lacking, open studies and case series were also examined. According to the previous edition, four levels of recommendation were defined on the basis of levels of evidence, scientific strength of evidence and clinical effectiveness. Recommendations for symptomatic and prophylactic treatment of migraine and cluster headache were therefore revised with respect to previous 2001 guidelines and a section was dedicated to non-pharmacological treatment. This article reports a summary of the revised version published in extenso in an Italian version.

Predicting age- and dose-related responses to antihypertensive therapy: pooled analysis of two randomized clinical trials of valsartan alone and combined with hydrochlorothiazide

We evaluated the relationship between age and treatment response from pooled data from two randomized trials in which 1,464 patients with Stage 2 hypertension were treated with valsartan alone or in combination with hydrochlorothiazide (HCTZ). Multivariate models were constructed for two response variables: systolic blood pressure (SBP) achieved at week 8 and change from baseline in SBP at week 8. Increasing age and higher baseline SBP were associated with proportionally higher final SBP values. The highly significant age-related decline in treatment response was substantially reduced with valsartan plus HCTZ compared with valsartan alone. Adverse event rates were generally comparable across the treatment groups. This analysis indicates that both age and baseline SBP should be considered when selecting antihypertensive therapy for patients with Stage 2 hypertension; for many older patients, initial therapy with both valsartan and HCTZ may be necessary, but in younger patients, one drug may be appropriate. However, because >87% of the study participants were White, it is unclear whether these results are applicable to other ethnic groups.

Management of hypertension and cerebrovascular disease in the elderly

Cardiovascular disease and stroke disproportionately affect the elderly. The risk for stroke and transient ischemic attack increases exponentially with age. Blood pressure is a potent modifiable target for reducing the risk for stroke in the elderly. In elderly patients with isolated systolic hypertension and those with intracranial atherosclerotic disease, blood pressure lowering has consistently been shown to be well tolerated and effective in reducing the risk for stroke and its complications. Evidence suggests that ambulatory blood pressure monitoring may provide a more sensitive means of detecting patients at risk and monitoring therapeutic effect. Agents that modify the renin-angiotensin system, particularly angiotensin receptor blockers, may confer additional benefit in stroke protection beyond blood pressure lowering. Several clinical trials currently in progress promise to provide guidance regarding the optimal choice of agent and degree of blood pressure lowering for prevention of stroke and cognitive decline in elderly patients.

Efficacy and safety of two treatment combinations of hypertension in very elderly patients

The study compared valsartan/amlodipine combination with irbesartan/hydrochlorothiazide (HCTZ) combination in very elderly hypertensives. After a 4-week placebo period, 94 hypertensives, aged 75-89 years were randomized to valsartan 160mg/amlodipine 5mg or irbesartan 300mg/HCTZ 12.5mg for 24 weeks according to a prospective, parallel group study. After 4 weeks amlodipine or HCTZ was doubled in non-responders. Patients were checked every 4 weeks. At each visit clinical sitting, lying and standing blood pressure (BP), systolic BP (SBP) and diastolic BP (DBP) were evaluated, and an electrocardiogram was performed. At the end of the placebo period and of the treatment period a non-invasive 24-h ambulatory BP monitoring (ABPM) was performed and electrolytes and uric acid were evaluated. Both combinations significantly reduced ambulatory BP. In the valsartan/amlodipine group the mean reduction (-29.9/-15.6 for 24h, -28.6/-14.5mmHg for day-time and -26.2/-17.4mmHg for night-time SBP/DBP) was similar to that of the irbesartan/HCTZ group (-29.6/-15.4 for 24h, -29.3/-14.9mmHg for day-time and -25.4/-16.9mmHg for night-time SBP/DBP). Both combinations significantly reduced clinical sitting and lying BP values with no difference between treatments. BP changes from lying to standing position were significantly greater in the irbesartan/HCTZ group (-17.2/-9.1mmHg) than in the valsartan/amlodipine group (-10.1/-1.9mmHg, p<0.05 for SBP and p<0.01 for DBP vs. irbesartan/HCTZ). Potassium significantly decreased and uric acid significantly increased (-0.4mmol/l, p<0.05 and +0.5mg/dl, p<0.05 vs. baseline, respectively) only in the irbesartan/HCTZ group. In conclusion, both combinations were similarly effective in reducing ambulatory and clinical BP in very elderly hypertensives. However, valsartan/amlodipine offered some advantages in terms of less pronounced BP orthostatic changes and absence of metabolic adverse effects.

A large scale study of angiotensin II inhibition therapy in an elderly population: the CHANCE study

This 8-week, multicenter study evaluated the efficacy and safety of candesartan cilexetil (CC, 8-16 mg) in elderly (>65 years) hypertensive patients. Patients (n=3013) received CC 8 mg during 8 weeks which eventually doubled to CC 16 mg at week 4 if blood pressure remained uncontrolled (> or = 140/90 mmHg). At week 8, 65.5% of patients were normalized (BP < 140/90 mmHg). Mean changes at week 8 were -25.8, -13.2, and -12.7 mmHg for systolic, diastolic, and pulse pressure, respectively. Age, sex, and diabetic status did not influence the antihypertensive effect of CC. 68% of the patients treated with, but uncontrolled or intolerant of, prior antihypertensive treatment were normalized by CC 8-16 mg. In summary, CC 8-16 mg once daily was effective and well tolerated in the management of arterial hypertension in elderly subjects.