Ventricular and Vascular Remodelling – Effects of the Angiotensin II Receptor Blocker Telmisartan and/or the Angiotensin-Converting Enzyme Inhibitor Ramipril in Hypertensive Patients

[Sartans in the treatment of arterial hypertension: focus on telmisartan and azilsartan. A review]

The activity of the renin-angiotensin-aldosterone system is one of the main pathogenetic mechanisms underlying cardiovascular diseases at all stages of the cardiovascular continuum. This article discusses the role of telmisartan and azilsartan as the most powerful sartans in modern cardiology. Azilsartan and especially telmisartan have a significant organoprotection and are superior to other antihypertensive drugs in terms of lowering blood pressure. However, the effect of azilsartan on hard endpoints has not been studied while the efficacy of telmisartan on hard endpoints has been evaluated in plenty clinical trials including 3 large randomized clinical trials with several thousand patients. The article also presents calculations showing the better cost-effectiveness of telmisartan compared to azilsartan.

Chronic Use of Angiotensin Converting Enzyme Inhibitors and/or Angiotensin Receptor Blockers is Not Associated With Stroke After Noncardiac Surgery: A Retrospective Cohort Analysis

Background

Inhibition of the renin-angiotensin-aldosterone pathways reduces blood pressure and proliferation of vascular smooth muscles and may therefore reduce the risk of stroke. We tested the hypothesis that patients taking angiotensin converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) for at least 6 months have fewer postoperative strokes after non-neurological, noncarotid, and noncardiac surgeries than those who do not.

Methods

We considered adults who had noncardiac surgery at the Cleveland Clinic between January 2005 and December 2017. After excluding neurological and carotid surgeries, we assessed the confounder-adjusted association between chronic use of ACEIs/ARBs (during 6 preoperative months) and the incidence of postoperative stroke using logistic regression models.

Results

Postoperative strokes occurred in 0.26% (27/10,449) of patients who were chronic ACEI/ARBs users and in 0.18% (112/62,771) of those who were not. There was no significant association between ACEI/ARB use and postoperative stroke, with an adjusted odds ratio of 1.15 (95% confidence interval [CI]: 0.91-1.44; P=0.24). Secondarily, there was no association between exposures to ACEIs and postoperative stroke, versus no such exposure (adjusted odds ratio 0.88, 95% CI: 0.65-1.19; P=0.33). Similarly, there was no association between exposure to ARBs and postoperative stroke, versus no such exposure (adjusted odds ratio 1.05, 95% CI: 0.75-1.48; P=0.75).

Conclusion

We did not detect an effect of chronic ACEI/ARB use on postoperative strokes in patients who had non-neurological, noncarotid and noncardiac surgery; however, power was extremely limited.

Optimization of Pharmacotherapy Within the Framework of a Patient-oriented Approach in the Treatment of Hypertension in Multimorbidity Patients (Clinical Case and Literature Review)

Arterial hypertension (AH) remains one of the main causes of disability and death worldwide, including in Russia. At the same time, the risks of coronary and cerebrovascular events increase in the presence of additional risk factors. The most common modifiable risk factors are metabolic disorders, including pre-diabetes, dyslipidemia, peripheral arterial atherosclerosis, and obesity, which also imposes certain features on the choice of optimal pharmacotherapy. Currently, the terminology of comorbid conditions continues to be discussed depending on their pathogenesis and the presence or absence of dominance of one disease over others, i.e. polymorbidity, comorbidity and multimorbidity. At the same time, “associative polymorbidity” is distinguished with a certain set of diseases that often occur in conjunction with each other with individual susceptibility of the body. One of the most common phenotypes of polymorbidity occurring in all age groups in both sexes is cardiometabolic, which is based on the formation of insulin resistance, sympathetic overactivity and chronic inflammation. This article provides a clinical example of the use of a fixed combination of angiotensin II receptor blocker telmisartan and calcium channel blocker amlodipine with the addition of an I1-imidazoline receptor agonist moxonidine in real clinical practice in a polymorbid cardiometabolic patient with target organ damage (left ventricular hypertrophy and microalbuminuria). High antihypertensive (favorable effect on 24-hour blood pressure, especially in the early morning) and organoprotective effectiveness of this combination, its possibilities in correcting additional risk factors (reduced heart rate, body weight and a positive effect on metabolic parameters), due to a synergistic effect on the central pathogenetic mechanisms of hypertension and obesity – insulin resistance and sympathetic overactivity.

Hypoxia-induced mitochondrial reactive oxygen species (mtROS) differentially regulates smooth muscle cell (SMC) proliferation of pulmonary and systemic vasculature

BACKGROUND

Vascular remodeling plays a pivotal role in regulation of hypoxia-mediated pulmonary and systemic hypertension via the phenotypic modulation of smooth muscle cells (SMCs) of pulmonary and systemic arteries, respectively. Mitochondria serve as putative oxygen (O₂) sensors, and consequently, adaptations to hypoxia are mediated via HIF (hypoxia-inducible factors) activation, which impinges on mitochondrial function by suppressing the mitochondrial activity. Therefore, we explored the implication of hypoxia-mediated mitochondrial stress in pulmonary and systemic arterial remodeling.

METHODS

The hypoxic (10% O₂) effect on human pulmonary artery and aortic SMCs was examined in vitro by cell viability assay, proliferation index, autophagy, and comet assays. Mitochondrial ROS (mtROS), membrane potential (MMP), and mitochondrial morphology were assessed using mitochondrial-selective fluorescent probes. Further, the cell cycle distribution was analyzed by flow cytometry using propidium iodide staining.

RESULTS

Our data indicate no significant alterations in cell viability and active proliferation of hypoxic PASMCs; however, an excessive rise in mtROS production and disrupted MMP, accompanied by enhanced DNA damage and reduced autophagy was observed, highlighting the 'apoptosis resistance' phenotype in these cells. Conversely, in hypoxia-treated hASMCs, a modest rise in mtROS levels was associated with reduced DNA damage; followed by upregulated autophagy; increased S-phase DNA content and cell viability, depicting the cytoprotective effect of hypoxia-induced autophagy against mitochondrial damage in hASMCs.

CONCLUSION

Our findings suggest that differential impact of mtROS on proliferative capacity may contribute to the variable hypoxic responses in pulmonary and systemic vasculature. Therefore, targeting mtROS may serve as an effective therapeutic strategy to prevent hypoxia-induced hypertension.

Antihypertensive and Target-Organ Protective Properties of Telmisartan and Hydrochlorothiazide Single-Pill Combination

The most important result of the revision of the European and Russian guidelines for the management of arterial hypertension (AH) was a special focus on initializing antihypertensive treatment with single-pill combinations (SPCs) in majority patients with AH. Combination of the angiotensin II receptor blocker and thiazide diuretic is one of the possible first line SPCs in the absence of specific clinical conditions according to the new guidelines. In this regard, SPC of telmisartan and hydrochlorothiazide (HCT), worth special noticing in the classes of sartans and thiazide diuretics, since both drugs have a long clinical experience and large body of evidence of antihypertensive efficacy and safety, as well as telmisartan also has a number of superior target-organ protective and metabolic properties distinguishing it from other members of the class. In real clinical practice TANDEM study telmisartan and its SPC with HCT showed high antihypertensive efficacy and good tolerability in patients with all AH grades and with isolated systolic AH and allowed to achieve target blood pressure levels in the most of patients. Long-lasting effect is another essential characteristic of telmisartan, this feature allows to control blood pressure throughout the day, including the morning surge, which is the most “dangerous” in terms of cardiovascular risk. Telmisartan also provide powerful target-organ protection realized at the level of all AH target-organs. Finally, another unique pharmacological property of telmisartan and its combination with HCT is a favourable effect on the carbohydrate and lipid profile, which comprises of increasing tissue sensitivity to insulin, normalizing blood glucose levels, reducing blood total cholesterol, low-density lipoprotein cholesterol and triglycerides and thereby reducing risk of atherosclerosis development and progression. Telmisartan/HCT SPC should be recommended for wide use in hypertensive patients to control blood pressure, protect end-organs, improve prognosis and reduce cardiovascular risk due to its high antihypertensive efficacy, the ability to provide the large target-organ protection and a beneficial metabolic effect.

Egg White-Derived Antihypertensive Peptide IRW (Ile-Arg-Trp) Inhibits Angiotensin II-Stimulated Migration of Vascular Smooth Muscle Cells via Angiotensin Type I Receptor

Excessive proliferation, inflammation, oxidative stress, and migration induced by angiotensin II (Ang II), occurring in vascular smooth muscle cells (VSMCs) during vascular remodelling, are major pathogenesis of hypertension. Antihypertensive peptides derived from food proteins are promising alternatives in preventing/treating hypertension and associated complications. In addition to reducing high blood pressure in spontaneously hypertensive rats, egg white ovotransferrin-derived antihypertensive IRW (Ile-Arg-Trp) was shown to exert antiproliferative, antioxidant, and anti-inflammatory effects in A7r5 cells (a vascular smooth muscle cell line) against Ang II stimulation, further indicating its potential in retarding vascular remodelling. Since its regulatory role in migration of VSMC is unclear, the objective of this study was to evaluate the antimigrant activity of IRW in Ang II-stimulated A7r5 cells. It was found that IRW could downregulate matrix metallopeptidase 9 (MMP9) expression and inhibit migration of Ang II-stimulated A7r5 cells, which was associated with inactivation of p38/MAPK signaling. More importantly, the antimigrant activity of IRW in Ang II-stimulated A7r5 cells was dependent on angiotensin type I receptor (AT1R). Our study provided the first evidence that egg ovotransferrin-derived antihypertensive peptide IRW inhibited migration of VSMCs.

Effect of 24-Week Treatment with Telmisartan on Myocardial Structure and Function: Relationship to Insertion/Deletion Polymorphism of the Angiotensin-Converting Enzyme Gene

The aim of the present study was to assess the effect of treatment with the angiotensin II receptor blocker telmisartan for 24 weeks on myocardial structure and function in patients with essential hypertension, and the relationship between this effect and the structural polymorphism of the angiotensin-converting enzyme (ACE) gene. Thirty-five patients with essential hypertension and left ventricular hypertrophy (LVH) without other associated morbidity were included in an open-label, non-comparative study. The patients were treated with telmisartan 40-80 mg once daily. In the final analysis, there were 29 patients who received the full course of treatment and were evaluated echocardiographically before and after treatment by the same blinded investigator, and myocardial structure and function were analysed. The myocardial mass of the left ventricle was determined in M-mode. Assessment of diastolic function of transmitral blood flow was performed using pulsed Doppler echocardiography. All patients were genotyped for insertion/deletion (I/D) polymorphism of the ACE gene. Telmisartan produced a significant reduction in left ventricular mass index from 140.4 ± 48.6 to 128.7 ± 40.6 g/m2 that was accompanied by an improvement in characteristics of diastolic function. The decrease in LVH was more significant in the ID genotype group than in the II and DD groups. Thus, prolonged treatment with telmisartan is accompanied by an improvement in myocardial structure, expressed as a reduction in left ventricular mass and function that is more marked in patients with ID genotype of the ACE gene.

Rationale and Design of the Cardiac Magnetic Resonance Imaging Substudy of the ONTARGET Trial Programme

Angiotensin-converting enzyme (ACE) inhibitors have been shown to improve cardiovascular disease outcomes in high-risk patients, but evidence for the cardioprotective effects of angiotensin II receptor blockers (ARBs) is less extensive. The ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET) and the parallel Telmisartan Randomized AssessmeNt Study in aCE iNtolerant subjects with cardiovascular Disease (TRANSCEND) - which together form The ONTARGET Trial Programme – are long-term, large-scale, double-blind, multinational outcome studies with the primary objectives of determining if the combination of the ARB telmisartan 80 mg and the ACE inhibitor ramipril 10 mg is more effective than ramipril 10 mg alone, and if telmisartan is at least as effective as ramipril (in the case of ONTARGET), and if telmisartan is superior to placebo (in the case of TRANSCEND), in providing cardiovascular protection for high-risk patients. A pre-defined substudy is being conducted within The ONTARGET

Trial Programme to compare the effects of these agents, alone and in combination, on cardiac structure and function. The substudy overcomes criticisms of many previous studies, which have been performed in small numbers of patients using suboptimal methodology, by evaluating changes in left ventricular structure and function using sophisticated technology provided by magnetic resonance imaging (MRI). Some 300 randomized patients within ONTARGET, recruited from selected centres in Australia, Canada, Germany, Hong Kong, New Zealand and Thailand, will have MRI undertaken at baseline and at 2-year follow-up. As this method of assessing left ventricular dysfunction is somewhat time-consuming, expensive and complex, and in the light of current interest in the role of B-type natriuretic peptide (BNP) as a simple, inexpensive diagnostic and prognostic tool, the substudy will also examine whether changes in BNP during follow-up correlated with changes in left ventricular dysfunction.

Carotid artery intima-media thickness and the renin-angiotensin system

Carotid artery intima-media thickness (IMT) is a biomarker for cardiovascular disease that also predicts the risk of cardiovascular mortality. Angiotensin-converting enzyme (ACE) inhibition is a unique therapeutic modality because it both treats hypertension and improves arterial health and cardiovascular disease outcomes. Controversy exists regarding the role of ACE inhibitors and angiotensin receptor blockers (ARBs) in IMT regression. Our article provides an update on how ACE inhibitors and ARBs could play a role in decreasing IMT.

"Sit back, observe, and wait." Or is there a pharmacologic preventive treatment for cerebral aneurysms?

Intracranial aneurysms (IA) are a relatively frequent vascular abnormality. The prevailing opinion is that cerebral aneurysmal disease is related to hemodynamic and genetic factors, associated with structural weakness in the arterial wall which was acquired by a specific, often unknown, event. Possibly the trigger moment of aneurysm formation may depend on the dynamic arterial growth, which is closely related to aging/atherosclerosis. In most individuals, an endovascular/microsurgical approach is possible in order to obliterate the IA. However, in a number of patients with an unruptured IA (UIA), the neurosurgeon's decision is to just "sit back, observe, and wait", based on the favorable natural history of some of the UIAs. Furthermore, some individuals need to be kept under close observation since they have a higher chance of developing IA, especially those with at least two affected first-degree relatives with an IA, subjects with polycystic kidney disease, and patients who have undergone an aneurysm intervention. In these examples prophylactic strategies should be adopted, if it is at all possible. The main question is deciding the best option of clinical treatment for these cases, when surgical approach is contraindicated, or for those subjects who are more prone to develop an IA. In the present article, we hypothetically suggest a pharmacologic form of treatment with statins, beta-adrenergic blocker agents, and/or angiotensin-converting-enzyme inhibitor/angiotensin II receptor blockers to inhibit or slow down IA formation, taking into consideration some pathophysiological aspects related to aneurysmal development, such as: hemodynamic stress, arterial wall inflammation, nitric oxide formation, and atheromatous disease.

Should all patients at high cardiovascular risk receive renin-angiotensin system blockers?

Despite considerable advances in preventative treatment during the last two decades, the increasing burden of cardiovascular (CV) disease constitutes an urgent need for new therapeutic strategies to reduce CV mortality and morbidity in patients at high CV risk. Activation of the renin-angiotensin system (RAS) results in vasoconstrictive, proliferative and pro-inflammatory effects that contribute to the development of atherosclerosis. As a result, the RAS is implicated at all stages of the 'CV continuum' that links risk factors such as hypertension and dyslipidaemia with major CV events, congestive heart failure (CHF) and CV death. The RAS therefore represents a rational and ideal therapeutic target in CV risk reduction strategies. Both angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) have been shown to promote beneficial effects on end-organ damage, such as decreases in arterial stiffness and left ventricular hypertrophy (LVH). Several trials have shown that ACE inhibitors and ARBs reduce CV risk in patients with specific risk factors. Furthermore, the HOPE study and, more recently, the ONTARGET® study have shown that ramipril and telmisartan reduce CV risk in patients with a high CV risk profile across the 'CV continuum'. Telmisartan is the first ARB to demonstrate CV prevention in patients at high CV risk, similar to that of the gold-standard ACE inhibitor, ramipril. This extensive clinical trial evidence suggests that ACE inhibitors or ARBs should be part of the standard treatment for patients at risk of CV events. ARBs may represent a preferred option due to their unsurpassed tolerability.

Differences in Left Ventricular Diastolic Dysfunction between Eccentric and Concentric Left Ventricular Hypertrophy in Hypertensive Patients with Preserved Systolic Function

Left ventricular (LV) hypertrophy (LVH) may be eccentric or concentric (2 × LV posterior wall thickness relative to LV end-diastolic dimension ≤ 0.42 or > 0.42, respectively). The LV diastolic function between age-matched hypertensive patients with eccentric and concentric LVH was compared in the present study. Echocardiography was used to measure LV mass index (LV mass/body surface area; LVMI) as an index of LVH. LV diastolic function was assessed by measurements of peak early transmitral flow velocity ( E)/peak late transmitral flow velocity ( A) (the E/A ratio), peak early diastolic mitral annular velocity ( e′) and the E/e′ ratio. Although LVMI, E/A and e′ did not differ between the two groups, E/e′ was significantly higher (worse) in patients with concentric LVH (13.4 ± 5.4) than in those with eccentric LVH (11.1 ± 3.6). Among hypertensive patients with LVH, those with concentric LVH may, therefore, have more severe LV diastolic dysfunction than those with eccentric LVH even if their LVMIs, which reflect the degree of LVH, are similar.

Telmisartan: a review of its pharmacodynamic and pharmacokinetic properties

IMPORTANCE OF THE FIELD

Telmisartan belongs to the angiotensin II type 1 (AT1) receptor antagonizing class of antihypertensives, which are widely recognized and increasingly prescribed because of their good tolerability. Moreover, due to the results of the ONTARGET trial program, telmisartan was the first AT1 receptor antagonist to receive approval for the prevention of cardiovascular events in cardiovascular high risk patients, thereby, indicating that its clinical importance will further increase.

AREAS COVERED IN THIS REVIEW

This article reviews the pharmacokinetic and pharmacodynamic properties of telmisartan with a special focus on novel pharmacokinetic characteristics of the drug.

WHAT THE READER WILL GAIN

An overview of the published data regarding the pharmacokinetic properties of telmisartan as well as a summary of the results from selected small exploratory and large clinical outcome trials involving telmisartan.

TAKE HOME MESSAGE

Telmisartan is a safe and effective alternative for the treatment of hypertension. Moreover, due to its good tolerability, an increasing use of telmisartan in cardiovascular high risk patients can be anticipated. This will grant further experimental and clinical research on AT1 receptor-independent pharmacodynamics of telmisartan as well as on telmisartan-related drug safety issues.

Have the renin-angiotensin-aldosterone system perturbations in cardiovascular disease been exhausted?

The renin-angiotensin-aldosterone system (RAAS) plays an important role in blood pressure control and volume homeostasis. Inappropriate activation of the RAAS has been implicated in the pathogenesis of hypertension and related cardiovascular disease. Several classes of agents that block RAAS signaling have been shown to be effective antihypertensives and to have cardioprotective and renoprotective properties. Because blockade of the RAAS is incomplete with any of the currently available monotherapies, combinations of these agents have been tested and shown to provide additional clinical benefit in patients with hypertension and various forms of cardiovascular and renal disease.

Do we need more than just powerful blood pressure reductions? New paradigms in end-organ protection

Antihypertensive therapy can lower the risk of cardiovascular morbidity and mortality. Yet, partly because of inadequate dosing, wrong pharmacological choices, and poor patient adherence, hypertension control remains suboptimal in the majority of hypertensive patients. Achieving greater blood pressure control requires a multifaceted approach that raises awareness of hypertension, uses effective therapies, and improves adherence. Particular classes of antihypertensive therapy have beneficial actions beyond blood pressure and studies have evaluated differences in cardiovascular protection among classes. The LIFE and HOPE studies showed between-class differences that may be due to effects other than blood pressure-lowering. In the ONTARGET study, telmisartan and ramipril provided similar cardiovascular protection but adherence was higher with telmisartan, which was better tolerated. This difference in compliance is likely to be important for long-term therapy. The selection of an agent for cardiovascular protection should depend on an appreciation of its composite properties, including any beneficial effects on tolerability and increased patient adherence, as these are likely to be advantageous for the long-term management of hypertension. This review examines the evidence that the effects beyond blood pressure provided by some antihypertensive agents can also lower the risk of cardiovascular, cerebrovascular, and renal events in patients with hypertension.

Angiotensin-converting enzyme insertion/deletion polymorphism associated with acute respiratory distress syndrome among caucasians

Studies investigating the association between angiotensin-converting enzyme (ACE) insertion/deletion polymorphisms and the risk of acute respiratory distress syndrome (ARDS) report conflicting results. The objective of the present study was to summarize quantitatively the evidence for such a relationship. Two investigators independently searched the MEDLINE (January 1966 - October 2009) and EMBASE (January 1980 - October 2009) databases. This meta-analysis included six case-control studies, which included 514 ARDS cases and 2619 controls. The combined results based on all studies showed that patients with ARDS had a significantly higher frequency of the ACE deletion/deletion (DD) genotype (odds ratio [OR] 1.56; 95% confidence interval [CI] 1.22, 2.00) than controls. When stratifying for race, no significant differences in genotype distribution were found except that Caucasian patients with ARDS had a significantly higher frequency of the DD genotype (OR 1.65; 95% CI 1.27, 2.13) than controls. This meta-analysis suggests that ACE insertion/deletion polymorphisms may be associated with ARDS among Caucasians.

Telmisartan: a different angiotensin II receptor blocker protecting a different population?

The ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET()) showed that the angiotensin II receptor blocker (ARB) telmisartan was as protective as the reference-standard ramipril in a broad cross-section of patients at increased cardiovascular risk, but was better tolerated. Telmisartan has a unique profile among ARBs, with a high affinity for the angiotensin II type 1 receptor, a long duration of receptor binding, a high lipophilicity and a long plasma half life. This leads to sustained and powerful blood pressure lowering when compared with the first marketed ARBs, such as losartan and valsartan. Some pharmacological properties of telmisartan clearly distinguish it from other members of the ARB class and may contribute to the clinical effects seen with telmisartan. A class effect for ARBs cannot be assumed. To date, telmisartan is the only ARB that has been shown to reduce cardiovascular risk in at-risk cardiovascular patients.

New standards in hypertension and cardiovascular risk management: focus on telmisartan

Blockade of the renin–angiotensin system is an important approach in managing high blood pressure, and has increasingly been shown to affect cardiovascular disease processes mediated by angiotensin II throughout the cardiovascular and renal continua. Telmisartan is an angiotensin II receptor blocker (ARB) displaying unique pharmacologic properties, including a longer half life than any other ARB, that result in large and sustained reductions of blood pressure. In patients with mild-to-moderate hypertension, telmisartan has proved superior to other antihypertensive agents (valsartan, losartan, ramipril, perindopril, and atenolol) in controlling blood pressure particularly towards the end of the dosing interval. There is also clinical evidence that telmisartan reduces left ventricular hypertrophy, reduces arterial stiffness and the recurrence of atrial fibrillation, and confers renoprotection. The ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET^®) study has demonstrated that telmisartan has similar cardiovascular protective effects to ramipril in a large, high-risk patient population but was better tolerated. The powerful and sustained blood pressure control apparent in clinical trials, together with cardiovascular protection and tolerability demonstrated in ONTARGET^® means that telmisartan may be a preferred option for patients with hypertension.

Left ventricular mass and volume with telmisartan, ramipril, or combination in patients with previous atherosclerotic events or with diabetes mellitus (from the ONgoing Telmisartan Alone and in Combination With Ramipril Global Endpoint Trial [ONTARGET])

The ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET) showed that the angiotensin receptor blocker telmisartan 80 mg was not inferior to the angiotensin-converting enzyme inhibitor ramipril 10 mg, and the combination no more effective than ramipril alone, in decreasing morbidity and mortality in patients with cardiovascular disease or high-risk diabetes. Although therapy targeting angiotensin II is known to decrease left ventricular (LV) mass and volume, the relative influence of angiotensin-converting enzyme inhibitor inhibitors and angiotensin receptor blocker, and their combination, on the heart remains unclear in this population. Magnetic resonance imaging was performed in 287 patients enrolled in ONTARGET, across 8 centers in 6 countries, at randomization and after 2-year treatment (90, 100, and 97 patients in the ramipril, telmisartan, and combination therapy groups, respectively). Baseline patient characteristics showed higher frequencies of coronary artery disease, Asian ethnicity, and use of statins and beta blockers than the main ONTARGET trial. LV mass decreased in all groups (p <0.0001 for each), but there were no significant differences in change in LV mass or volume among groups, except that LV mass index decreased more on combination versus telmisartan (p = 0.04). Key determinants of LV mass decrease were a history of hypertension (p = 0.03), baseline mass (p <0.0001), and decrease in systolic blood pressure (p <0.0001). The best magnetic resonance imaging predictor of composite events was end-systolic volume (p <0.0001). In conclusion, telmisartan and ramipril had similar effects on LV mass and volume, and combination therapy was not more effective, in high-risk patients with cardiovascular disease. These results are consistent with the major outcome findings of the main ONTARGET study.

Regression of Left Ventricular Mass by Antihypertensive Treatment

Blood pressure–lowering therapy reduces left ventricular mass, but the question of whether differences exist among drug classes has not been fully resolved. Our aim was to compare the effects of diuretics, β-blockers, calcium channel blockers, angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers on left ventricular mass regression in patients with hypertension on the basis of prospective, randomized comparative studies. We performed meta-analyses, involving pooled pairwise comparisons of the drug classes and of each class versus other classes statistically combined, and meta-regression analyses to identify the determinants of the regression. The 75 relevant publications involved 84 pairwise comparisons and 6001 patients. Regression of left ventricular mass was significantly less ( P =0.01) with β-blockers (9.8%) than with angiotensin receptor blockers (12.5%), but none of the other analyzable pairwise comparisons between drug classes revealed significant differences ( P >0.10). In addition, β-blockers showed less regression than the other 4 classes statistically combined ( P <0.01), and regression was more pronounced with angiotensin receptor blockers versus the others ( P <0.01). In multivariable meta-regression analysis on all of the treatment arms, β-blocker treatment was a significant and negative predictor of the regression (−3.6%; P <0.01), but this was not the case for the other drug classes, including angiotensin receptor blockers. In conclusion, β-blockers show less regression of left ventricular mass, whereas angiotensin receptor blockers may induce larger regression. The inferiority of β-blockers appears to be more convincing than the superiority of angiotensin receptor blockers.

Vascular and metabolic effects of angiotensin II receptor blockers

Angiotensin II receptor blockers (ARBs) are widely used in patients with hypertension, heart failure and type 2 diabetes mellitus (T2DM). Several large clinical trials have demonstrated that these agents are effective in reducing cardiovascular mortality and morbidity. These benefits are partly independent of the degree of blood pressure reduction and most likely related to ARBs' anti-inflammatory, metabolic and vascular effects. Clinical studies showed that the anti-inflammatory effect of ARBs could be related to the dosage and/or the length of the treatment. In large clinical trials, ARBs have inconsistently reduced the risk of new-onset T2DM. Among ARBs, only losartan significantly reduced serum uric acid levels. Moreover, it has been demonstrated that ARBs improve endothelial dysfunction in patients with hypertension and/or coronary artery disease (CAD), while all but one of the studies proved that these agents could usually, after 6-12 months of therapy, induce regression of vascular hypertrophy in hypertensive patients. These positive effects could be relevant to vascular protection and, together with the blood pressure reduction, constitute the background of the improved outcome observed in clinical studies on mortality and/or morbidity in hypertensive, high-risk and CAD patients. The clinical significance of the different potency of ARBs needs to be investigated further in specific and adequately powered trials.

Histological study of right ventricle-pulmonary artery valved conduit implantation (RPVC) in dogs with pulmonic stenosis

We examined whether right ventricle-pulmonary artery valved conduit (RPVC) implantation can overcome the disadvantages of current procedures for pulmonic stenosis (PS). We histologically evaluated the feasibility of RPVC using a homograft in PS model dogs. Eight dogs underwent pulmonary artery banding (PAB) and then 12 weeks later were assigned to PAB (n=4) or PAB+RPVC (n=4) groups. Dogs in the PAB group received no treatment throughout the experimental period, whereas the PAB+RPVC group underwent RPVC. At 1 year after PAB, hearts and conduits were explanted from euthanized dogs and histologically evaluated. The ratios (%) of myocardial fibrosis on right ventricle (RV) epicardial, median and endocardial layers were significantly lower in the PAB+RPVC, than in the PAB group. The ratio of myocardial fibrosis on left ventricular (LV) epicardial and endocardial layers were significantly lower in the PAB+RPVC, than in the PAB group. Neo-intimal thickness in the anastomosis areas of the Denacol and PAB+RPVC groups was 42.77 +/- 30.19 and 88.30 +/- 27.24 microm, respectively, with no significant differences between the groups. Calcification and neo- intima hypertrophy were not obvious in the valve area. Immunohistological staining showed that the internal surface of the anastomosis and intermediate areas were positive for endothelial cells. We concluded that RPVC using a bioprosthetic graft can apparently overcome the disadvantages of current procedures for pulmonic stenosis.

Review: Cardioprotective effects of telmisartan in uncomplicated and complicated hypertension

The development of angiotensin II receptor blockers (ARB) as a new class of drugs for the management of hypertension has elicited the attention of many clinicians worldwide with the aim of improving blood pressure (BP) control as well as cardiovascular protection.AmongARB telmisartan has been shown to be characterised by an antihypertensive efficacy fully covering the 24-hour period, thereby allowing to antagonise the adverse effects of early morning BP rise on cardiovascular risk. Other specific effects of the drug are represented by its favourable metabolic profile (particularly on insulin sensitivity) and neutral effects on sympathetic cardiovascular function.These properties are coupled with cardioprotective effects, documented by the evidence that the drug: 1) is effective in favouring the regression of cardiac and vascular organ damage, 2) reduces arterial stiffness and improves vascular distensibility and 3) reverses the endothelial dysfunction typical of the hypertensive state particularly when complicated by renal failure, diabetes, obesity or metabolic syndrome. Several of these properties can account for the results of the ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET), documenting the beneficial effects on the drug on cardiovascular morbidity and mortality.

Candesartan decreases carotid intima-media thickness by enhancing nitric oxide and decreasing oxidative stress in patients with hypertension

Candesartan has been reported to produce nitric oxide (NO) and to decrease oxidative stress in animal studies. We investigated candesartan's effect on the production of NO and oxidative stress as well as on carotid intima-media thickness (IMT) in hypertensive patients. One-hundred age-matched hypertensive patients were enrolled into an angiotensin II receptor blocker (ARB) group (n=50) or a non-ARB group (n=50). The ARB group was treated with candesartan 8 mg and, when needed, Ca channel blockers, angiotesin-converting enzyme (ACE) inhibitors, and/or beta-blockers. The non-ARB group was treated with drugs other than ARB. Carotid IMT was assessed by echocardiography before and 12 and 24 months after treatment. The urine levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), an indicator of oxidative stress, and the serum levels of NOx, an indicator of NO, were measured. Blood pressure decreased to below 140/90 mmHg to the same extent in both groups. Carotid IMT decreased significantly in the ARB group, but not in the non-ARB group, at 12 and 24 months after treatment. The urine levels of 8-OHdG decreased significantly at 6 and 12 months after treatment in the ARB group but did not decrease in the non-ARB group. The serum levels of NOx increased significantly at 6 and 12 months after treatment in the ARB group but not in the non-ARB group. In conclusion, candesartan decreases carotid IMT by enhancing NO production and decreasing oxidative stress in patients with hypertension.

New opportunities in cardiovascular patient management: a survey of clinical data on the combination of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers

Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) differ in their actions on the renin-angiotensin-aldosterone system (RAAS). ACE inhibitors prevent the formation of angiotensin II, although angiotensin II may still be generated by alternative pathways. However, ACE inhibitors interrupt bradykinin breakdown, which in turn potentially enhances nitric oxide and prostacyclin mechanisms. In contrast, ARBs selectively prevent the binding of angiotensin II to the angiotensin type 1 (AT(1)) receptor while leaving the potentially beneficial effects of the AT(2) receptor unaffected. The supposition is that dual blockade of the RAAS effectively overcomes the harmful effects of angiotensin II mediated by the AT(1) receptor while offering the additional effects of the ACE inhibitor. This concept was first evaluated clinically more than a decade ago in small-scale studies that were not sufficiently powered to conclusively demonstrate benefits from dual blockade. Subsequently, larger-scale trials have been conducted to determine the effects of a combination of an ACE inhibitor and an ARB in combating the effects of angiotensin II at different stages of cardiovascular and renal disease. This review explores these data in areas, such as hypertension, renal disease, and cardiovascular disease, and draws on this preliminary evidence to support the rationale for the Ongoing Telmisartan Alone in Combination with Ramipril Global Endpoint Trial (ONTARGET) program, which aims to fully explore the clinical end points and effects of dual RAAS blockade in patients at high risk for cardiovascular outcomes.

Effective treatment of hypertension by AT(1) receptor antagonism: the past and future of telmisartan

Lowering blood pressure is the most effective treatment method to ensure a reduction in the total risk for cardiovascular morbidity and mortality. The renin-angiotensin system plays an important role in volume homeostasis and blood pressure regulation and is a target for several groups of pharmaceutical agents. Angiotensin II receptor blockers represent the newest class of antihypertensive compounds. They prevent the binding of angiotensin II to the subtype 1 receptor (AT(1)), which is believed to mediate most of the physiological actions relevant to the regulation of blood pressure. Telmisartan, a widely used AT(1) receptor antagonist, is a highly selective compound with high potency, a long duration of action and a tolerability profile similar to placebo. Numerous randomized clinical trials and community-based studies have demonstrated that oral telmisartan and combinations of telmisartan with hydrochlorothiazide are at least as effective in lowering blood pressure as all other hypertensive medications. This has been demonstrated in different populations of adult patients with mild-to-moderate essential hypertension, including patients with coexisting Type 2 diabetes, metabolic syndrome or renal impairment. Several large-scale, long-term, clinical endpoint studies are in progress to assess the beneficial effects of telmisartan on hypertension-related end-organ damage in patients at high risk of renal, cardiac and vascular damage whose blood pressure is well controlled. The most recent data from clinical trials and latest research regarding telmisartan will be reviewed in this article.