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The use of multiple drug regimens is increasingly recognized as a tacit requirement for the management of hypertension, a necessity fueled in part by rising rates of metabolic syndrome and diabetes. By targeting complementary pathways, combinations of antihypertensive drugs can be applied to provide effective blood pressure control while minimizing side effects and reducing exposure to high doses of individual medications. In addition, combination therapies, including angiotensin converting enzyme (ACE) inhibitors and calcium channel blockers (CCBs), have the added benefit of reducing cardiovascular mortality and morbidity over other dual therapies while providing equivalent blood pressure control. It is possible that angiotensin receptor blockers (ARBs), which unlike ACE inhibitors are minimally affected by upregulation of alternative pathways for angiotensin II accumulation following long-term treatment, would also provide such outcome benefits. At issue, however, is maintaining patient compliance, as adding medications is known to reduce adherence to treatment regimens. The purpose of this review is to summarize existing trial data for the long-term safety and efficacy of a recent addition to the armamentarium of dual-antihypertensive therapeutic options, the telmisartan/amlodipine single pill combination. The areas where long-term data are lacking, notably clinical information regarding minorities and women, will also be discussed.

Thomas Mengden1, Sakir Uen1, Peter Bramlage21Centre of Vascular Medicine, Herz- und Gefäß-Campus, Bad Nauheim, Germany; 2Institute for Cardiovascular Pharmacology and Epidemiology, Mahlow, GermanyAbstract: Hypertension treatment and control is largely unsatisfactory when guideline-defined blood pressure goal achievement and maintenance are considered. Patient- and physician-related factors leading to non-adherence interfere in this respect with the efficacy, tolerability, and convenient use of pharmacological treatment options. Blockers of the renin–angiotensin system (RAS) are an important component of antihypertensive combination therapy. Thiazide-type diuretics are usually added to increase the blood pressure lowering efficacy. Fixed drug–drug combinations of both principles like candesartan/hydrochlorothiazide (HCTZ) are highly effective in lowering blood pressure while providing improved compliance, a good tolerability, and largely neutral metabolic profile. Comparative studies with losartan/HCTZ have consistently shown a higher clinical efficacy with the candesartan/HCTZ combination. Data on the reduction of cardiovascular endpoints with fixed dose combinations of antihypertensive drugs are however scarce, as are the data for candesartan/HCTZ. But many trials have tested candesartan versus a non-RAS blocking comparator based on a standard therapy including thiazide diuretics. The indications tested were heart failure and stroke and particular emphasis was put on elderly patients or those with diabetes. In patients with heart failure, for example, the fixed dose combination might be applied in patients in whom individual titration resulted in a dose of 32 mg candesartan and 25 mg HCTZ which can then be combined into one tablet to increase compliance with treatment. Also in patients with stroke the fixed dose combination might be used in patients in whom maintenance therapy with both components is considered. Taken together candesartan/HCTZ assist both physicians and patients in achieving long-term blood pressure goal achievement and maintenance.Keywords: chronic heart failure, stroke, diabetes, angiotensin receptor blocker, patients, physicians, persistence, compliance

Carlos FerrarioHypertension and Vascular Disease Center, Wake Forest University School of Medicine, Winston-Salem, NC, USAAbstract: Endothelial dysfunction is the common link between cardiovascular disease risk factors and the earliest event in the cascade of incidents that results in target organ damage. Angiotensin II, the terminal pressor effector arm of the renin-angiotensin-aldosterone system, increases blood pressure (BP) by vasoconstriction and sodium and fluid retention, and has a pro-oxidative action that induces endothelial dysfunction and contributes to vascular remodeling. Angiotensin receptor blockers (ARBs) reduce BP and morbidity and mortality in patientswith hypertension, ventricular hypertrophy, diabetes mellitus, and renal disease. Olmesartan medoxomil is a long-acting, well-tolerated, effective ARB that prevents or reverses endothelial dysfunction in animal models of atherosclerosis, hypertension, diabetes, nephropathy, and retinopathy. Olmesartan medoxomil, a prodrug of olmesartan approved for the treatment of hypertension, has been shown to ameliorate endothelial dysfunction in patients with hypertension or diabetes. In randomized studies, the drug reduces vascular inflammation and the volume of large atherosclerotic plaques, increases the number of regenerative endothelial progenitor cells in the peripheral circulation, improves endothelium-dependent relaxation, and restores the normal resistance vessel morphology. Importantly, the impact of olmesartan medoxomil on endothelial dysfunction is thought to be independent of BP lowering.Keywords: endothelial dysfunction, angiotensin receptor blocker, olmesartan medoxomil, hypertension, atherosclerosis&nbsp

The renin angiotensin aldosterone system (RAAS) plays an important role in the pathophysiology of cardiovascular disease. Angiotensin converting enzyme inhibitors (ACEi) have proven benefit in reducing cardiovascular events in patients at high risk. Angiotensin receptor blockers (ARB) have been demonstrated to have benefit in the management of heart failure and to be non-inferior to ACEi in patients with left ventricular dysfunction after a myocardial infarction (MI). Yet until now, there has been no trial to support the use of the ARB for vascular protection. The ONTARGET study showed that the ARB telmisartan conserved 95% of the vascular protective properties of the ACEi ramipril, given at similar doses to a similar patient group as had been previously shownin the HOPE study to benefit from ACE inhibition with ramipril. The TRANSCEND study in a similar population of patients who were intolerant of ACEi despite the primary endpoint being neutral, showed a trend to a benefit for the combined secondary endpoint of cardiovascular death, MI and stroke, with excellent tolerance of the ARB. The reasons for neutral result of the TRANSCEND study result include an underpowered study, and pre-treatment with a RAAS inhibitor in a high proportion of patients. These studies indicate that an ARB can be used for vascular protection in high risk individuals in the place of an ACEi. However ACEi will probably remain the first choice due to the greater body of supportive evidence.

A fixed-dose combination of losartan/hydrochlorothiazide (HCTZ) therapy may be a logical choice for antihypertensive treatment, including for initial therapy in patients with blood pressure elevation >20/10 mmHg above treatment target. The renin–angiotensin– aldosterone–system-activating effect of hydrochlorothiazide augments the efficacy of blocking the angiotensin II type 1 (AT1) receptor with losartan. Some adverse effects associated with hydrochlorothiazide, including increased risk for new-onset diabetes mellitus, may be offset by losartan. Losartan was frequently administered with hydrochlorothiazide in the Losartan Intervention For Endpoint reduction in hypertension (LIFE) study, in which there was a 25% risk reduction for stroke in the losartan-based compared with the atenolol-based treatment group. The efficacy, tolerability, and convenience of losartan/HCTZ combination therapy may increase patient compliance and lower risk for stroke, a devastating outcome in patients with hypertension.

Endothelial dysfunction is the initial pathophysiological step in a progression of vascular damage that leads to overt cardiovascular and chronic kidney disease. Angiotensin II, the primary agent of the renin-angiotensin system (RAS), has a central role in endothelial dysfunction. Therefore, RAS blockade with an angiotensin receptor blocker (ARB) and/or angiotensin-converting enzyme (ACE) inhibitor provides a rational approach to reverse endothelial dysfunction, reduce microalbuminuria, and, thus, improves cardiovascular and renal prognosis. ARBs and ACE inhibitors act at different points in the RAS pathway and recent evidence suggests that there are differences regarding their effects on endothelial dysfunction. In addition to blood pressure lowering, studies have shown that ARBs reduce target-organ damage, including improvements in endothelial dysfunction, arterial stiffness, the progression of renal dysfunction in patients with type 2 diabetes, proteinuria, and left ventricular hypertrophy. The ONgoing Telmisartan Alone in combination with Ramipril Global Endpoint Trial (ONTARGET) Programme is expected to provide the ultimate evidence of whether improved endothelial function translates into reduced cardiovascular and renal events in high-risk patients, and to assess possible differential outcomes with telmisartan, the ACE inhibitor ramipril, or a combination of both (dual RAS blockade). Completion of ONTARGET is expected in 2008.

Daniel Duprez1, Keith Ferdinand2, Das Purkayastha3, Rita Samuel3, Richard Wright41University of Minnesota, Minneapolis, MN, 2Atlanta Clinical Research Centers, Atlanta, GA, 3Novartis Pharmaceuticals Corporation, East Hanover, NJ, 4Pacific Heart Institute, Santa Monica, CA, USABackground: Stage 2 hypertension often requires combination antihypertensive therapy. Ambulatory blood pressure monitoring (ABPM) is a useful tool for assessing antihypertensive drugs and their combinations.Objective: To compare the effect of a moderate dose of angiotensin receptor blocker/calcium channel blocker (ARB/CCB) combined with a diuretic versus a maximal dose of ARB with a diuretic on 24-hour ambulatory blood pressure monitoring (ABPM) and other derived ambulatory blood pressure (ABP) parameters.Methods: The EXforge As compared to Losartan Treatment ABPM substudy was a randomized, double-blind, parallel-group, active-control, forced-titration study of patients with Stage 2 hypertension that compared the efficacy of initial treatment with valsartan/amlodipine 160/5 mg (n = 48) or losartan 100 mg (n = 36). At week 3, hydrochlorothiazide (HCTZ) 25 mg was added in both treatment groups. ABP was measured at baseline and at week 6. Additionaly, 24-hour ABP, nighttime (10 pm to 6 am) and daytime (6 am to 10 pm) ABP, and ABP load (percentage of readings above 140/90 mmHg) were determined.Results: Eighty-four patients (48 ARB/CCB/HCTZ, 36 ARB/HCTZ) had ABPM at baseline and at week 6. Reductions of systolic/diastolic ABP were greater in the ARB/CCB/HCTZ group than in the ARB/HCTZ group for 24-hour mean ABP (–22.0/–13.3 versus –17.4/–8.1 mmHg), as well as nighttime ABP (–22.2/–13.3 versus –16.2/–7.4 mmHg), daytime ABP (–21.9/–13.0 versus –18.1/–8.6 mmHg), ABP in the last 4 hours of the dosing period (–21.5/–13.5 versus –17.0/–7.7 mmHg), and ABP load (21.7%/12.8% versus 30.8%/20.0%).Conclusion: Initiating antihypertensive treatment with moderate doses of ARB/CCB with a diuretic is more effective in lowering nighttime and daytime ABP and reducing ABP load than a maximal dose of an ARB with a diuretic.Keywords: antihypertensive drugs, ambulatory blood pressure, ambulatory blood pressure monitoring, combination therapy, valsartan, amlodipine, hydrochlorothiazide, losartan

Appropriate control of blood pressure (BP) in hypertensive patients still represents the major therapeutic goal in the treatment of hypertension. Despite the growing attention and wide range of antihypertensive agents available in the clinical scenario, the target of BP below the advised thresholds of 140/90 mmHg is, unfortunately, often unreached. For this reason, the search for new antihypertensive agents is still ongoing. Azilsartan medoxomil, a new angiotensin receptor blocker that has been recently introduced in the clinical arena, represents the eighth angiotensin receptor blocker currently available for BP control. The aim of this paper is to describe the efficacy and safety profile of this new compound, reviewing available data obtained from both pre-clinical and clinical studies.

The role of drugs in new cancer occurrence and cancer-related death is a major concern. Recently, a meta-analysis raised the possibility that angiotensin receptor blockers (ARBs) might have an adverse effect on patients. This generated a significant debate until the publication of two further meta-analyses, neither of which demonstrated an increased risk of new cancer occurrence or cancer-related death with the use of ARBs in patients with hypertension, heart failure, and/or nephropathy. This illustrates that the results of meta-analyses should be interpreted cautiously and critically as bias, such as selection bias, might lead to erroneous conclusions. Overall, the bulk of evidence today indicates that ARBs are not associated with increased cancer risk.

Inder S Anand1, Anita Deswal2, Dean J Kereiakes3, Das Purkayastha4, Dion H Zappe41Veterans Administration Medical Center, Minneapolis, MN, USA; 2Michael E DeBakey VA Medical Center, Houston, TX, USA; 3The Christ Hospital Heart and Vascular Center, Cincinnati, OH, USA; 4Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA; Clinical trial registration information: www.clinicaltrials.gov/ct2/show/NC T00294086 Unique identification number: NC T00294086Background: The safety of once-daily (qd) dosing of valsartan in heart failure (HF) patients is not known. Hypothesis: This 10-week, double-blind trial examined the relative safety and efficacy of valsartan administered qd versus twice-daily (bid).Methods: HF patients (NYHA class II–III) receiving diuretics (87%), angiotensin-converting enzyme inhibitors (98%), beta-blockers (92%), aldosterone antagonists (25%), or digoxin (32%) were randomized to valsartan 40 mg bid (n = 60) or 80 mg qd (n = 55) and titrated to a maximum dose of 320 mg/day; doubling the dose every 2 weeks. Clinical and biochemical parameters were measured at Weeks 2, 4, 6, and 10.Results: The average dose of valsartan at the end of study was 245 mg in the bid group vs 256 mg in the qd group (P = NS). Similar proportions of patients tolerated qd vs bid dosing (bid 67% vs qd 68%). Outcome measures including reduction in blood pressure, incidence of hypotension, renal impairment, orthostatic dizziness or fatigue, changes in serum K+, creatinine, cystatin-C, and estimated glomerular filtration rate were similar between the 2 groups at all time-points. Brain natriuretic peptide levels decreased and plasma renin activity increased from baseline by the same amount in both groups at all time-points.Conclusion: Valsartan administered qd has a similar safety and tolerability profile with comparable 24-hour RAAS blockade, as assessed by increases in PRA, as bid dosing in patients with moderate to severe (NYHA class II–III) heart failure.Keywords: heart failure, angiotensin receptor blocker, valsartan

Introduction: This study evaluated the effects on blood pressure (BP) of valsartan 160 mg or losartan 100 mg addition to amlodipine 5 mg in hypertensive patients. Methods: 221 patients with inadequately controlled BP (DBP ≥ 90 mmHg) after 4 weeks of treatment with amlodipine 5 mg were randomized to receive losartan/amlodipine combination therapy or valsartan/amlodipine combination therapy for 4 weeks in a cross-over study design. At the end of the wash-out period and of each treatment period, clinic and ambulatory BP measurements were recorded. Results: 166 patients completed the study. Both combination treatments induced a greater ambulatory BP reduction than did monotherapy. However, the further mean reductions in BP versus monotherapy were significantly greater with the valsartan/amlodipine combination (SBP/DBP: −7.9 ± 3.4/−6.5 ± 2.6 mmHg for 24-hour, −8.0 ± 3.4/−6.6 ± 2.7 mmHg for daytime; −7.7 ± 3.3/−6.4 ± 2.7 mmHg for nighttime) than with the losartan/amlodipine combination (SBP/DBP: −5.5 ± 2.8/−4.2 ± 2.1 mmHg for 24-hour, −5.7 ± 2.9/−4.4 ± 2.2 mmHg for daytime; −4.8 ± 2.8/−3.7 ± 2.2 mmHg for nighttime; P < 0.01 vs valsartan/amlodipine). The incidence of adverse events with valsartan/amlodipine (8%) and losartan/amlodipine (9%) was lower than that observed with amlodipine monotherapy (17%; P < 0.05 vs combinations). Conclusion: Valsartan 160 mg plus amlodipine 5 mg produced greater BP reductions than losartan 100 mg plus amlodipine 5 mg.