Rationale, design, and baseline characteristics of 2 large, simple, randomized trials evaluating telmisartan, ramipril, and their combination in high-risk patients: the Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial/Telmisartan Randomized Assessment Study in ACE Intolerant Subjects with Cardiovascular Disease (ONTARGET/TRANSCEND) trials

ACE-inhibitor, AT1-receptor-antagonist, or both? A clinical pharmacologist's perspective after publication of the results of ONTARGET

Clinical Pharmacology is commonly accepted to be a bridging discipline between basic science observations and clinical practice. Today, it should be a major task of the clinical pharmacologist in academia to provide support in the interpretation of preclinical and clinical study data, to develop evidence-based treatment guidelines and to serve as drug expert supporting all disciplines of clinical medicine with specific pharmacological and therapeutic knowledge. The results of the ONTARGET-trial confront both researchers and clinicians with the unexpected truth that AT(1)-receptor-blockade with an angiotensin-receptor-blocker (ARB) does not seem to have superior therapeutic benefit compared with an ACE-inhibitor (ACE-I) at reducing fatal and nonfatal cardiovascular events. The combination of the two drugs was associated with more adverse events without an increase in benefit. Therefore, the crucial question 'ACE-I, ARB, or both?' requires a new and critical appraisal depending on the medical indication for which these renin-angiotensin-system (RAS)-inhibitors are used: In a population of high-risk patients suffering from cardiovascular disease or diabetes mellitus, the evidence to favor an ARB over an ACE-I is still limited after ONTARGET and because of the higher costs for ARBs one can rather support the old therapeutic advice that ARBs are equally effective as ACE-Is and therefore therapeutic alternatives for patients with ACE-I intolerance. With respect to a very moderate additive BP-lowering effect of dual therapy with an ACE-I and an ARB seen in metaanalysis which was not even clearly attributable to dual RAS-inhibition and the increased adverse event rate in the combination treatment group of ONTARGET, this regimen seems not to be recommendable for the treatment of hypertension. Dual-RAS-blockade using an ACE-I-ARB-combination is an effective therapy to treat proteinuria and might be of therapeutic benefit especially in diabetic patients without concomitant diseases. There may be a therapeutic rationale to prefer ARBs over ACE-Is in well-selected patients with congestive heart failure (CHF) because a considerable amount of angiotensin II (Ang II) is produced independent of angiotensin-conversion-enzyme (ACE) in the failing heart and is therapeutically unaffected by ACE-I treatment. The results of the Val-HeFt and the CHARM-added-study revealed additive effects of an ARB on heart failure related morbidity and mortality when added to existing therapy with an ACE-I suggesting a role for ACE-I-ARB-combination treatment in well selected heart failure patients. Independent of the medical indication for its use, the concept of dual RAS-blockade with an ARB-ACE-I-combination should clinically be used with caution and a close monitoring of potassium levels and kidney function. Although the results of ONTARGET revealed equity of ramipril and telmisartan at reducing fatal and nonfatal cardiovascular events, we should not forget that pharmacologically not all ARBs are the same and the question if the study results of ONTARGET with telmisartan are transferable to the complete class of ARBs still merits further investigation.

On target to dual block RAS?

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers are thought to possess cardioprotective, cerebroprotective, and nephroprotective properties. Both classes of agents can prevent or reverse endothelial dysfunction and atherosclerosis, thereby potentially reducing the risk of cardiovascular events. Such a reduction has been shown with angiotensin-converting enzyme inhibitors in patients with coronary artery disease, but no such data are scarce with angiotensin receptor blockers (Valsartan in Acute Myocardial Infarction study). Both angiotensin-converting enzyme inhibitors and angiotensin receptor blockers have been shown to reduce damage in target organs, such as the heart and kidney, and to decrease cardiovascular mortality and morbidity in patients with congestive heart failure. These drugs (especially angiotensin receptor blockers) may successfully prevent atrial fibrillation and play a protective role in metabolic syndrome. In some clinical settings, combined therapy angiotensin-converting enzyme inhibitors with angiotensin receptor blocker (double blockade of the renin-angiotensin- aldosterone system) may appear the most effective.

Inhibiting angiotensin type 1 receptors as a target for diabetes

BACKGROUND

Angiotensin type 1 (AT1) receptor blockers (ARBs) are used to treat hypertension and related end-organ damage. ARBs have been recognised as regulators of glucose- and lipid metabolism. Clinical trials demonstrated that AT1 receptor antagonism lowers the risk for type 2 diabetes compared with other antihypertensive therapies. Blockade of AT1 receptors reduces cardiovascular morbidity and mortality in diabetic subpopulations. The mechanisms of the insulin-sensitizing/anti-diabetic effect are not fully understood, and may involve AT1 receptor-dependent pathways and 'pleiotropic' actions of ARBs including activation of insulin-sensitising PPARgamma.

OBJECTIVE

In clinical practice questions about AT1 receptor blockade in diabetes have to be answered. Firstly, is selective AT1-receptor blockade superior to ACE inhibition in preventing diabetes and reducing cardiovascular end points in diabetic patients? Secondly, is an ARB with PPARgamma-activating properties superior to one without this action?

RESULTS/CONCLUSION

The Ongoing Telmisartan Alone and in Combination with Ramipril Global End point Trial (ONTARGET) has provided information to answer these questions, and is discussed.

The role of renin-angiotensin-aldosterone system-based therapy in diabetes prevention and cardiovascular and renal protection

Hypertension increases the risk of type 2 diabetes mellitus (T2DM) and cardiovascular disease. In addition to lowering blood pressure, blockade of the renin-angiotensin-aldosterone system (RAAS) reduces the risk of new-onset T2DM and offers renal protection. Using a MEDLINE search, we identified multiple trials that reported the incidence of T2DM in patients taking inhibitors of RAAS. In this review, we will discuss the RAAS as a potential target in diabetes prevention and the mechanisms through which inhibitors of this system achieve such an important effect. We will also shed light on the beneficial cardiovascular and renal effects of RAAS blockade. Although multiple studies have demonstrated that inhibitors of RAAS, especially angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, can reduce the incidence of T2DM, randomized controlled studies are still needed to further elucidate their exact role in diabetes prevention.

Optimal treatment of the diabetic patient with multivessel disease

Diabetes is emerging as a major source of cardiovascular morbidity and mortality. The atherosclerosis associated with diabetes has a complex etiology with even more complicated manifestations, such as multivessel and diffuse coronary disease. The optimal management of the diabetic patient with multivessel disease poses a special challenge in terms of the selection of the revascularization strategy and medical therapies. In this article, we assess the evidence accumulated to date and discuss ongoing studies that will help better inform this intricate decision-making process.

Effects of the angiotensin-receptor blocker telmisartan on cardiovascular events in high-risk patients intolerant to angiotensin-converting enzyme inhibitors: a randomised controlled trial

BACKGROUND

Angiotensin-converting enzyme (ACE) inhibitors reduce major cardiovascular events, but are not tolerated by about 20% of patients. We therefore assessed whether the angiotensin-receptor blocker telmisartan would be effective in patients intolerant to ACE inhibitors with cardiovascular disease or diabetes with end-organ damage.

METHODS

After a 3-week run-in period, 5926 patients, many of whom were receiving concomitant proven therapies, were randomised to receive telmisartan 80 mg/day (n=2954) or placebo (n=2972) by use of a central automated randomisation system. Randomisation was stratified by hospital. The primary outcome was the composite of cardiovascular death, myocardial infarction, stroke, or hospitalisation for heart failure. Analyses were done by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00153101.

FINDINGS

The median duration of follow-up was 56 (IQR 51-64) months. All randomised patients were included in the efficacy analyses. Mean blood pressure was lower in the telmisartan group than in the placebo group throughout the study (weighted mean difference between groups 4.0/2.2 [SD 19.6/12.0] mm Hg). 465 (15.7%) patients experienced the primary outcome in the telmisartan group compared with 504 (17.0%) in the placebo group (hazard ratio 0.92, 95% CI 0.81-1.05, p=0.216). One of the secondary outcomes-a composite of cardiovascular death, myocardial infarction, or stroke-occurred in 384 (13.0%) patients on telmisartan compared with 440 (14.8%) on placebo (0.87, 0.76-1.00, p=0.048 unadjusted; p=0.068 after adjustment for multiplicity of comparisons and overlap with primary outcome). 894 (30.3%) patients receiving telmisartan were hospitalised for a cardiovascular reason, compared with 980 (33.0%) on placebo (relative risk 0.92, 95% CI 0.85-0.99; p=0.025). Fewer patients permanently discontinued study medication in the telmisartan group than in the placebo group (639 [21.6%] vs 705 [23.8%]; p=0.055); the most common reason for permanent discontinuation was hypotensive symptoms (29 [0.98%] in the telmisartan group vs 16 [0.54%] in the placebo group).

INTERPRETATION

Telmisartan was well tolerated in patients unable to tolerate ACE inhibitors. Although the drug had no significant effect on the primary outcome of this study, which included hospitalisations for heart failure, it modestly reduced the risk of the composite outcome of cardiovascular death, myocardial infarction, or stroke.

FUNDING

Boehringer Ingelheim.

Telmisartan to prevent recurrent stroke and cardiovascular events

BACKGROUND

Prolonged lowering of blood pressure after a stroke reduces the risk of recurrent stroke. In addition, inhibition of the renin-angiotensin system in high-risk patients reduces the rate of subsequent cardiovascular events, including stroke. However, the effect of lowering of blood pressure with a renin-angiotensin system inhibitor soon after a stroke has not been clearly established. We evaluated the effects of therapy with an angiotensin-receptor blocker, telmisartan, initiated early after a stroke.

METHODS

In a multicenter trial involving 20,332 patients who recently had an ischemic stroke, we randomly assigned 10,146 to receive telmisartan (80 mg daily) and 10,186 to receive placebo. The primary outcome was recurrent stroke. Secondary outcomes were major cardiovascular events (death from cardiovascular causes, recurrent stroke, myocardial infarction, or new or worsening heart failure) and new-onset diabetes.

RESULTS

The median interval from stroke to randomization was 15 days. During a mean follow-up of 2.5 years, the mean blood pressure was 3.8/2.0 mm Hg lower in the telmisartan group than in the placebo group. A total of 880 patients (8.7%) in the telmisartan group and 934 patients (9.2%) in the placebo group had a subsequent stroke (hazard ratio in the telmisartan group, 0.95; 95% confidence interval [CI], 0.86 to 1.04; P=0.23). Major cardiovascular events occurred in 1367 patients (13.5%) in the telmisartan group and 1463 patients (14.4%) in the placebo group (hazard ratio, 0.94; 95% CI, 0.87 to 1.01; P=0.11). New-onset diabetes occurred in 1.7% of the telmisartan group and 2.1% of the placebo group (hazard ratio, 0.82; 95% CI, 0.65 to 1.04; P=0.10).

CONCLUSIONS

Therapy with telmisartan initiated soon after an ischemic stroke and continued for 2.5 years did not significantly lower the rate of recurrent stroke, major cardiovascular events, or diabetes. (ClinicalTrials.gov number, NCT00153062.)

Review: Recurrent stroke: where do we stand with the secondary prevention of noncardioembolic ischaemic strokes?

Strokes recur in 6—20% of the patients, most commonly within the first year; after a TIA or minor stroke; most recurrences will occur within the first 90 days. Our ability to identify patients at high risk is poor and most recurrent strokes cannot be explained by traditional risk factors. In 30—45% of the cases the second stroke will be of a different subtype. Moreover, patients are faced with other risks, like cardiac events and cognitive decline. With the population aging, the need for timely and effective secondary prevention strategies is more pressing than ever. This paper summarizes recent advances in pharmacological secondary prevention after a non-cardioembolic ischaemic stroke, and highlights critical questions still in need of answers.

Treatment of hypertension in heart failure with preserved ejection fraction: role of the kidney

Heart failure can present clinically as primarily diastolic or systolic dysfunction or both. There is an increasing awareness that heart failure can occur in the presence of a normal left ventricular ejection fraction. Heart failure with normal left ventricular ejection fraction is frequently referred to as diastolic heart failure because of the presence of diastolic left ventricular dysfunction evident from impaired left ventricular relaxation. This article focuses on the treatment of hypertension and the role the kidney plays in selecting appropriate agents.

The role of the renin-angiotensin system in atrial fibrillation and the therapeutic effects of ACE-Is and ARBS

Atrial fibrillation (AF) is the most common rhythm disturbance in medical practice and represents a very expensive health problem. AF can be managed with the prevention of thromboembolism and either a rate control of rhythm strategy. As both strategies have important limitations, probably a preventative strategy in patients at risk of developing arrhythmia can be a more attractive option. The renin-angiotensin system (RAS) seems to be involved in the genesis of arrhythmia by the following two mechanisms: 1. the induction of atrial fibrosis and structural remodelling by mitogen-activated protein kinase (MAPK) expression and reduction of collagenase activity; 2. the induction of electrical remodelling by shortening of the atrial effective refractory period (AERP) and of the action potential duration. For these reasons it has been hypothesized that angiotensin-converting enzyme inhibitors (ACE-Is) and angiotensin-II receptor blockers (ARBs) may play a role in preventing AF recurrence. The aim of the present review was to analyse evidence supporting the usefulness of RAS inhibition in patients with AF in order to focus on which specific subset of patients it would most favour. After reviewing the literature, we conclude that, although many studies and meta-analysis have supported the advantage of RAS block in preventing AF recurrence, it is premature to recommend the use of ACE-Is and ARBs specifically for the prevention of AF. However we believe that as these drugs are safe and manageable, they should be considered the drugs of choice in patients with AF and coexisting clinical conditions such as hypertension, coronary disease, heart failure and diabetes mellitus.

Renal outcomes with telmisartan, ramipril, or both, in people at high vascular risk (the ONTARGET study): a multicentre, randomised, double-blind, controlled trial

BACKGROUND

Angiotensin receptor blockers (ARB) and angiotensin converting enzyme (ACE) inhibitors are known to reduce proteinuria. Their combination might be more effective than either treatment alone, but long-term data for comparative changes in renal function are not available. We investigated the renal effects of ramipril (an ACE inhibitor), telmisartan (an ARB), and their combination in patients aged 55 years or older with established atherosclerotic vascular disease or with diabetes with end-organ damage.

METHODS

The trial ran from 2001 to 2007. After a 3-week run-in period, 25 620 participants were randomly assigned to ramipril 10 mg a day (n=8576), telmisartan 80 mg a day (n=8542), or to a combination of both drugs (n=8502; median follow-up was 56 months), and renal function and proteinuria were measured. The primary renal outcome was a composite of dialysis, doubling of serum creatinine, and death. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00153101.

FINDINGS

784 patients permanently discontinued randomised therapy during the trial because of hypotensive symptoms (406 on combination therapy, 149 on ramipril, and 229 on telmisartan). The number of events for the composite primary outcome was similar for telmisartan (n=1147 [13.4%]) and ramipril (1150 [13.5%]; hazard ratio [HR] 1.00, 95% CI 0.92-1.09), but was increased with combination therapy (1233 [14.5%]; HR 1.09, 1.01-1.18, p=0.037). The secondary renal outcome, dialysis or doubling of serum creatinine, was similar with telmisartan (189 [2.21%]) and ramipril (174 [2.03%]; HR 1.09, 0.89-1.34) and more frequent with combination therapy (212 [2.49%]: HR 1.24, 1.01-1.51, p=0.038). Estimated glomerular filtration rate (eGFR) declined least with ramipril compared with telmisartan (-2.82 [SD 17.2] mL/min/1.73 m(2)vs -4.12 [17.4], p<0.0001) or combination therapy (-6.11 [17.9], p<0.0001). The increase in urinary albumin excretion was less with telmisartan (p=0.004) or with combination therapy (p=0.001) than with ramipril.

INTERPRETATION

In people at high vascular risk, telmisartan's effects on major renal outcomes are similar to ramipril. Although combination therapy reduces proteinuria to a greater extent than monotherapy, overall it worsens major renal outcomes.

Inhibition of the renin-angiotensin system and chronic kidney disease

Chronic kidney disease (CKD), a major worldwide public-health problem which affects about 10% of the population, has an increased annual incidence rate of about 5-8%. This increased incidence is mainly due to type 2 diabetes and hypertension and the increasing incidence of elderly patients with CKD. Although the progression to end-stage renal failure (ESRF) is mainly based upon the underlying disease, comorbid conditions such as an initial low renal function, severe proteinuria, and high levels of blood pressure also play important roles in the development of ESRF. Since experimental and clinical evidence suggest that angiotensin II plays a central role in the progression of CKD, pharmacological inhibition of the renin-angiotensin-aldosteron system (RAAS) with angiotensin converting enzyme inhibitors or angiotensin II receptor antagonists has been suggested as first-line treatment for hypertension and prevention of ESRF in these patients. Aliskiren, a novel renin inhibitor is also a promising medical intervention. However, independently of the category of the drugs used, low target blood pressure levels seem to be equally or more important for the delay or prevention of CKD. In this review the results of studies with pharmacological inhibition of the RAAS in patients with diabetic and nondiabetic nephropathy is discussed.

Angiotensin receptor blockers: current status and future prospects

Angiotensin receptor blockers (ARBs), through their physiological blockade of the renin-angiotensin system, reduce morbidity and mortality associated with hypertension, heart failure, myocardial infarction, stroke, diabetic nephropathy, and chronic kidney disease. Among many attributes, excellent tolerability, and their ability to control hypertension for 24 hours with a positive effect on renal function position them as a useful choice for hypertension and related conditions. Because of the widespread actions of the renin-angiotensin system on critical tissues, treatment with ARBs may be beneficial in special populations. Ongoing and future studies will be needed to conclusively determine if ARBs also improve outcomes in patients with heart failure and preserved systolic function, atrial fibrillation, cognitive dysfunction, and kidney transplant recipients. Preliminary clinical data also suggest that combining ARBs and angiotensin-converting enzyme inhibitors may provide a more optimal blockade of the renin-angiotensin system and, therefore, may offer greater cardio- and nephroprotection. Future data will help delineate which ARBs and angiotensin-converting enzyme inhibitors are best combined and which patient populations might benefit from the dual blockade of the renin-angiotensin system.

Comparison of the effects of quinapril and irbesartan on P-wave dispersion in hypertensive patients

INTRODUCTION

P-wave dispersion (PWD) has been shown to be a non-invasive electrocardiographic predictor for development of atrial fibrillation (AF). Thus, it may be possible to attenuate AF risk through improvement of PWD. In this study, we compared the effects of an angiotensin-converting enzyme (ACE) inhibitor, quinapril, and an angiotensin receptor blocker (ARB), irbesartan, on PWD.

METHODS

A total of 38 newly diagnosed hypertensive patients were enrolled in the study. The patients were randomly assigned to receive treatment with either irbesartan (150-300 mg) or quinapril (20-40 mg). P-wave durations and PWD were measured at baseline and after 6 and 12 months of treatment. Echocardiographic examinations were performed at baseline and after 12 months of treatment.

RESULTS

Both drugs significantly reduced blood pressure to a similar degree (P<0.001). Deceleration time (both P<0.001) and isovolumetric relaxation time (both P=0.007) were also significantly reduced, whereas there was no significant change in the early diastolic flow/atrial contraction signal ratio. Both irbesartan and quinapril significantly decreased maximum P-wave duration (Pmax) (P<0.001 and P=0.002, respectively) and PWD (from 68.0+/-22.1 to 41.0+/-25.1 msec for irbesartan, and from 70.5+/-20.4 to 46.6+/-13.3 msec for quinapril; both P<0.001). Baseline and follow-up blood pressure, heart rate, echocardiographic findings, and P-wave values were not significantly different between the irbesartan and quinapril groups. No patient developed AF during follow-up. There was no significant correlation between PWD and blood pressure or diastolic function parameters.

CONCLUSION

Antihypertensive treatment with either irbesartan or quinapril is associated with significant reductions in Pmax and PWD.

Management of hypertension in patients with chronic kidney disease and diabetes mellitus

Treatment of patients at high risk for developing cardiovascular disease aims at controlling blood pressure, optimizing blood glucose levels, and providing renoprotection. Chronic kidney disease (CKD) and diabetes mellitus are prevalent causes of cardiovascular disease owing to associations with major cardiovascular risk factors, such as hypertension, and they are substantial health burdens. Even mild-to-moderate CKD and prehypertension increase cardiovascular risk. First-line agents for reducing cardiovascular risk are inhibitors of the renin-angiotensin system: angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs). In clinical trials, treatment of high-risk patients with ACE inhibitors and ARBs delays or prevents the onset of diabetes and prevents progression of renal disease and cardiovascular events, including cardiovascular mortality. Current evidence indicates that the clinical efficacy of these end points includes effects that may be beyond blood pressure reduction.

Current possibilities of ACE inhibitor and ARB combination in arterial hypertension and its complications

The renin-angiotensin-aldosterone system (RAAS) plays a crucial role in blood pressure regulation and hypertension-related complications. Angiotensin-converting enzyme inhibitors (ACEIs) were the first to be used to block the RAAS and now have many compelling indications in the treatment of hypertension and its cardiovascular and renal complications. Angiotensin II receptor blockers (ARBs), introduced 20 years later, have been shown to be equally as effective as antihypertensive treatment and are also associated with a lower number of side effects. Furthermore, in clinical trials ARBs and ACEIs were associated with comparable benefits for their most typical indications. This was confirmed in the 2007 New European Society of Hypertension/European Society of Cardiology (ESH/ESC) guidelines for the management of hypertension by comparable specific recommendations for ARB and ACEI treatment. There is sufficient theoretical background and, in some cases, also clinical evidence that combination therapy with ACEIs and ARBs may be more beneficial than monotherapy with either of the groups alone, both in uncomplicated hypertension and with concomitant heart failure or renal dysfunction. However, the combination of ACEI and ARB was not recommended in the ESH/ESC 2007 Guidelines. This may change after the publication of the Ongoing Telmisartan Alone and in Combination with Ramipril Global End point Trial (ONTARGET) study, the preliminary results of which have just been presented. In heart failure, recent studies have shown that the combination of ACEI and ARB decreases cardiovascular mortality and the number of hospitalizations due to aggravation of heart failure. These results have been reflected in the newest ESC guidelines of the heart failure treatment. Nephroprotective properties of the combination of ACEs and ARBs have been proved both in studies on nondiabetic and diabetic nephropathy. The potential benefits, indications in prespecified groups of patients, the most recent data from clinical trials and latest research regarding dual blockade of RAAS will be reviewed in this article.

Economic benefits of treating high-risk hypertension with angiotensin II receptor antagonists (blockers)

Hypertension is one of the leading risk factors for cardiovascular disease and represents a major health and economic burden. Most patients with high- or very high-risk hypertension have multiple cardiovascular risk factors with or without accompanying subclinical organ damage or established cardiovascular or renal disease. Patients with severe hypertension or with moderate hypertension and one to two additional risk factors have absolute 10-year risks of cardiovascular disease of 21-30% and 15-20%, respectively. Current European treatment guidelines recommend that antihypertensive therapy be initiated rapidly and aggressively in patients with high-risk hypertension. Most patients require two or more antihypertensive agents to achieve the strict blood pressure target of <130/80 mmHg. This article reviews the existing cost-effectiveness data on the use of angiotensin II receptor antagonists (blockers) [ARBs] in patients with high-risk hypertension. Aggressive ARB treatment of patients in the early (microalbuminuric) stages of diabetic nephropathy has a significant renoprotective effect, delaying the onset of overt (proteinuric) nephropathy. By slowing the progression of these patients to end-stage renal disease, substantial cost savings can be made. There is a paucity of cost-effectiveness data regarding the use of fixed-dose ARB plus thiazide diuretic combination therapies. Longitudinal cost-benefit studies of this attractive and efficacious first-line treatment option are needed.

Cardiovascular drugs as antidiabetic agents: evidence for the prevention of type 2 diabetes

Given the long-term health consequences and increasing incidence of type 2 diabetes, there is great interest to potentially prevent or delay its onset. Primary prevention studies have demonstrated that intensive exercise and weight reduction, and to a lesser extent certain antidiabetic agents, can reduce new onset diabetes in at-risk individuals. Results from post hoc analyses and secondary end-point outcomes of large randomized controlled trials of cardiovascular drugs suggest that these may also have beneficial effects, reducing the incidence of new onset diabetes in addition to their proven cardiovascular benefits. Multiple meta-analyses confirm that drugs primarily acting on the renin-angiotensin system (RAS) reduce the incidence of diabetes in the populations studied, perhaps via improved insulin sensitivity and/or effects on pancreatic beta cells. However, results from the recent Diabetes REduction Approaches with Medication study specifically failed to show a significant reduction in the incidence of diabetes with ramipril in individuals with abnormal glucose tolerance at baseline. There is only limited evidence that statins improve glucose tolerance, and although beta-blockers tend to have detrimental effects on glucose tolerance, newer agents with vasodilatory properties may confer benefits. With current guidelines, the use of cardiovascular drugs modifying the RAS will increase in at-risk individuals, but at present, they cannot be recommended to prevent diabetes.

Effects of angiotensin converting enzyme inhibitor and angiotensin II receptor antagonist combination on nitric oxide bioavailability and atherosclerotic change in Watanabe heritable hyperlipidemic rabbits

We investigated the effects of co-administration of an angiotensin-converting enzyme inhibitor (ACEI) and angiotensin type 1 receptor blocker (ARB) on nitric oxide (NO) bioavailability in genetically hyperlipidemic rabbits with our newly developed NO sensor. Plasma NO was measured using the new NO sensor in the abdominal aorta of anesthetized Watanabe heritable hyperlipidemic (WHHL) rabbits. Acetylcholine (ACh)-stimulated (20 microg in 5 min into the aortic arch) NO production was recorded after an 8 week per os pretreatment with 1) vehicle (control), 2) the ACEI enalapril (E: 3 mg/kg/day), 3) the ARB losartan (L: 30 mg/kg/day) and 4) enalapril (1.5 mg/kg/day)+losartan (15 mg/kg/day) (E+L). Intra-aortic infusion of ACh produced an increase in plasma NO concentration, which was significantly greater with all the drug treatments than with the control. E increased ACh-induced NO significantly more than L (by 6.9 nmol/L, and 4.7 nmol/L, respectively). E+L increased ACh-induced NO by 9.5 nmol/L, significantly more than either E or L. Plasma peroxynitrite concentration was 1.2 pmol/mg protein in the control group and significantly less than in the E- and L-group. The lowest peroxynitrite concentration was observed in the E+L group (0.5 pmol/mg protein), which was significantly lower than in the E-group and the L-group. Optical coherence tomography and histology of the thoracic aorta revealed that the plaque area decreased significantly more with the combination than with the monotherapy (p<0.01). In conclusion, the combined treatment with an ACEI and an ARB may have additive protective effects on endothelial function as well as atherosclerotic change.

Treating hypertension while protecting the vulnerable islet in the cardiometabolic syndrome

Hypertension, a multifactorial-polygenic disease, interacts with multiple environmental stressors and results in functional and structural changes in numerous end organs, including the cardiovascular system. This can result in coronary heart disease, stroke, peripheral vascular disease, congestive heart failure, end-stage renal disease, insulin resistance, and damage to the pancreatic islet. Hypertension is the most important modifiable risk factor for major health problems encountered in clinical practice. Whereas hypertension was once thought to be a medical condition based on discrete blood pressure readings, a new concept has emerged defining hypertension as part of a complex and progressive metabolic and cardiovascular disease, an important part of a cardiometabolic syndrome. The central role of insulin resistance, oxidative stress, endothelial dysfunction, metabolic signaling defects within tissues, and the role of enhanced tissue renin-angiotensin-aldosterone system activity as it relates to hypertension and type 2 diabetes mellitus are emphasized. Additionally, this review focuses on the effect of hypertension on functional and structural changes associated with the vulnerable pancreatic islet. Various classes of antihypertensive drugs are reviewed, especially their roles in delaying or preventing damage to the vulnerable pancreatic islet, and thus delaying the development of type 2 diabetes mellitus.

Review: The therapeutic role of RAS blockade in chronic heart failure

Cardiovascular disease represents a continuum that starts with risk factors such as hypertension and progresses to atherosclerosis, end-organ damage, and ultimately to chronic heart failure (CHF) and premature death. Renin-angiotensin system (RAS) blockade with angiotensin converting enzyme (ACE) inhibitors and/or angiotensin II type 1 receptor blockers (ARBs) has turned out to be beneficial at all stages of this continuum. Several mechanisms govern the progression of structural myocardial damage to end-stage CHF. Chronic neuroendocrine activation fosters left ventricular remodeling and dilatation and leads to clinical symptoms of CHF via forward/backward failure. RAS inhibition is a cornerstone of neuroendocrine blockade in CHF patients, and combined RAS blockade is especially effective in patients presenting with repetitive cardiac decompensations. This review focuses on the therapeutic role of inhibitors of different RAS components in chronic heart failure caused by systolic left ventricular dysfunction.

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.

Albuminuria and dementia in the elderly: a community study

BACKGROUND

Dementia is associated with microvascular disease of the retina. In this study, we examine whether cognitive status (normal cognition, mild cognitive impairment, and dementia) is associated with albuminuria, a microvascular disorder of the kidney.

STUDY DESIGN

Cross-sectional analysis.

SETTING & PARTICIPANTS

2,316 participants from the Cardiovascular Health Cognition Study who underwent brain magnetic resonance imaging and testing for albuminuria.

PREDICTOR

Doubling of albuminuria.

OUTCOME

Dementia defined according to neuropsychological and clinical evaluation.

MEASUREMENTS

Multinomial logistic modeling was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) of dementia and mild cognitive impairment with doubling of albuminuria compared with the odds with normal cognition.

RESULTS

283 participants (12.2%) had dementia, 344 (14.9%) had mild cognitive impairment, and 1,689 (72.9%) had normal cognition. Compared with participants with normal cognition, doubling of albuminuria was associated with increased odds of dementia (OR, 1.22; 95% CI, 1.15 to 1.29). Adjustment for prevalent cardiovascular disease and cardiovascular risk factors, lipid levels, C-reactive protein level, estimated glomerular filtration rate, and apolipoprotein E-4 genotype attenuated this association, but it remained statistically significant (OR, 1.12; 95% CI, 1.03 to 1.22). Mild cognitive impairment was associated with albuminuria on unadjusted analysis, but not with adjustment for other factors.

LIMITATIONS

Results are cross-sectional; causality cannot be imputed.

CONCLUSIONS

The odds of dementia increased in the presence of albuminuria. These findings suggest a role of shared susceptibility for microvascular disease in the brain and kidney in older adults.

Angiotensin receptor blockers: RAAS blockade and renoprotection

INTRODUCTION

Chronic kidney disease (CKD) is an increasingly prevalent public health concern and is associated with a high risk of adverse cardiovascular outcomes. Renal impairment is frequently associated with hypertension and there is compelling evidence of the benefits of antihypertensive therapy for reducing progression of kidney disease. The central role of the renin-angiotensin-aldosterone system (RAAS) in hypertension and renal disease has led to interest in the ability of RAAS-blocking agents to provide benefits beyond blood pressure control.

SCOPE

This review explores the mechanisms involved in CKD development, assesses markers of CKD progression, explores the role of the RAAS in renal disease, and examines RAAS blockade as a therapeutic option for renoprotection. For this purpose, a non-systematic literature review was conducted using the Medline database.

FINDINGS

Studies in patients with diabetic renal disease have shown that RAAS blockade with angiotensin converting enzyme (ACE)-inhibitors or angiotensin receptor blockers (ARBs) reduces progression of renal disease. Similarly, several studies have demonstrated the benefits of ACE inhibitors in non-diabetic renal disease, although few studies have been conducted with ARBs in this setting. At present, there is little evidence to determine the relative merits of ARBs and ACE inhibitors in terms of clinical outcomes, although ARBs appear to have advantages in terms of renal haemodynamics and measures of renal function.

CONCLUSIONS

The beneficial effects of ARBs, which result from a combination of antihypertensive, haemodynamic, antiproteinuric and pleiotropic mechanisms, provide a strong rationale for considering the use of these agents in the treatment of high-risk patients.

Lessons from ONTARGET

The recently published results of the ONTARGET trial shed a new light on the cardiovascular protection of patients at high risk of a cardiovascular event. Despite a number of trials looking at the efficacy of Angiotensin Converting Enzyme inhibitors (ACEis) or Angiotensin Receptor Blockers (ARBs) in the prevention of cardiovascular events in patients with specific high risk profiles, the question of the equivalence of ACEis and ARBs remained unanswered. The ONTARGET trial has shown that telmisartan 80 mg administered for a median duration of 4.5 years to patients at high risk of developing a major cardiovascular event, is equally effective to ramipril 10 mg. In addition, telmisartan was slightly better tolerated. The comparator ramipril has been chosen as it is currently the gold standard ACEi since the results of the HOPE study, in terms of the composite outcome of cardiovascular death, myocardial infarction and stroke. Moreover, ONTARGET is the first trial to test the hypothesis of superiority of adding an ARB (telmisartan 80 mg) to an ACEi (ramipril 10 mg) over the ACEi ramipril monotherapy in cardiovascular protection of the same broad range of high-risk patients. Surprisingly, despite a more pronounced blood pressure lowering, the combination of the two agents did not lead to an additional decrease in the number of events, but had significantly more side-effects compared to ramipril monotherapy. ONTARGET is a landmark study, performed according to the highest statistical and clinical standards, providing compelling evidence and clear answers to two important clinical questions.

Telmisartan, ramipril, or both in patients at high risk for vascular events

BACKGROUND

In patients who have vascular disease or high-risk diabetes without heart failure, angiotensin-converting-enzyme (ACE) inhibitors reduce mortality and morbidity from cardiovascular causes, but the role of angiotensin-receptor blockers (ARBs) in such patients is unknown. We compared the ACE inhibitor ramipril, the ARB telmisartan, and the combination of the two drugs in patients with vascular disease or high-risk diabetes.

METHODS

After a 3-week, single-blind run-in period, patients underwent double-blind randomization, with 8576 assigned to receive 10 mg of ramipril per day, 8542 assigned to receive 80 mg of telmisartan per day, and 8502 assigned to receive both drugs (combination therapy). The primary composite outcome was death from cardiovascular causes, myocardial infarction, stroke, or hospitalization for heart failure.

RESULTS

Mean blood pressure was lower in both the telmisartan group (a 0.9/0.6 mm Hg greater reduction) and the combination-therapy group (a 2.4/1.4 mm Hg greater reduction) than in the ramipril group. At a median follow-up of 56 months, the primary outcome had occurred in 1412 patients in the ramipril group (16.5%), as compared with 1423 patients in the telmisartan group (16.7%; relative risk, 1.01; 95% confidence interval [CI], 0.94 to 1.09). As compared with the ramipril group, the telmisartan group had lower rates of cough (1.1% vs. 4.2%, P<0.001) and angioedema (0.1% vs. 0.3%, P=0.01) and a higher rate of hypotensive symptoms (2.6% vs. 1.7%, P<0.001); the rate of syncope was the same in the two groups (0.2%). In the combination-therapy group, the primary outcome occurred in 1386 patients (16.3%; relative risk, 0.99; 95% CI, 0.92 to 1.07); as compared with the ramipril group, there was an increased risk of hypotensive symptoms (4.8% vs. 1.7%, P<0.001), syncope (0.3% vs. 0.2%, P=0.03), and renal dysfunction (13.5% vs. 10.2%, P<0.001).

CONCLUSIONS

Telmisartan was equivalent to ramipril in patients with vascular disease or high-risk diabetes and was associated with less angioedema. The combination of the two drugs was associated with more adverse events without an increase in benefit. (ClinicalTrials.gov number, NCT00153101 [ClinicalTrials.gov].).

Type 2 diabetes mellitus: prevention of macrovascular complications

Type 2 diabetes mellitus is a disease that affects a rapidly increasing number of patients. Most patients with Type 2 diabetes will develop vascular complications. This may be microvascular disease, such as nephropathy, retinopathy or polyneuropathy, and also macrovascular disease, such as coronary heart disease, stroke or peripheral artery disease. Optimal control of elevated blood glucose levels will reduce the symptoms of hyperglycemia and help to prevent the development of complications. In addition, treatment of hypertension and lipid disturbances has been shown to reduce the incidence and severity of vascular complications significantly. The current treatment goals focus on adequate and aggressive treatment of these three risk factors. The central dogma for treatment of blood glucose, blood pressure and cholesterol levels is 'the lower the better'. Ongoing trials evaluate the effect of further lowering these treatment goals and of specific types of medication on cardiovascular events.

Treatment of hypertension in individuals with the cardiometabolic syndrome: role of an angiotensin II receptor blocker, telmisartan

Arterial hypertension is a global public health problem owing to its high prevalence and association with increased risk for cerebral, cardiac and renal events. Hypertension frequently clusters with other cardiometabolic risk factors, such as dysglycemia, low levels of high-density lipoprotein cholesterol and high triglyceride levels. These, along with other factors such as central obesity, increased inflammation, endothelial dysfunction and thrombosis, are components of the metabolic syndrome. All guidelines recommend that the first-line therapy in metabolic syndrome should be based on lifestyle modification, consisting of diet and moderate exercise for at least 30 min/day. Concerning drug treatment of hypertension associated with other cardiometabolic risk factors, many results of head-to-head studies have demonstrated a reduction in new-onset Type 2 diabetes in hypertensive patients treated with angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, when compared with conventional antihypertensive therapy. The explanations of the different actions of both these drugs include several mechanisms related to pancreatic insulin release and insulin sensitivity improvement. Another mechanism by which the inhibition of the renin-angiotensin system may improve insulin sensitivity is through the partial peroxisome proliferator-activated receptor-gamma agonism of telmisartan. For that reason, telmisartan has been considered by some experts to be an antihypertensive agent that is particularly useful in the treatment of hypertension associated with cardiometabolic risk factors. The impact of the promising metabolic action exhibited by telmisartan on the outcome of hypertensive patients aggregating other cardiometabolic risk factors waits for adequately randomized and powered clinical trials.