Comparative effects of valsartan versus amlodipine on left ventricular mass and reactive oxygen species formation by monocytes in hypertensive patients with left ventricular hypertrophy

Evidence for benefits of angiotensin receptor blockade beyond blood pressure control

Elevated levels of angiotensin II result in oxidative stress and endothelial dysfunction, which initiate atherogenic pathologic processes that are important in cardiovascular disease development. Angiotensin II induces its deleterious effects primarily through the type 1 receptor; these effects are inhibited by angiotensin II receptor blockers (ARBs) directly at the receptor level. Angiotensin II may potentiate protective mechanisms through stimulation of the type 2 receptor, which is not blocked by ARBs. Accumulating data suggest that blockade of angiotensin II production or activity provides vascular and cardioprotective benefits, such as reduction of atrial fibrillation, acute myocardial infarction, and heart failure events. Moreover, blockade of the renin-angiotensin system has been shown to offer renal protection in subjects with and without diabetes mellitus and to reduce the risk of new-onset diabetes.

The relationship between nighttime dipping in blood pressure and cerebral hemodynamics in nonstroke patients

Inadequate dipping in nighttime blood pressure (BP) is associated with cerebrovascular disease. The authors aimed to determine whether inadequate nocturnal dipping was associated with abnormalities in cerebrovascular hemodynamics in individuals without stroke. Participants in this study underwent 24-hour ambulatory BP monitoring followed by morning transcranial Doppler measurements of blood flow velocities (BFVs) in the middle cerebral artery during supine rest, head-up tilt, hypocapnia, and hypercapnia. Nighttime BP decline by <10% was considered nondipping. Of the 102 nonstroke participants (mean age, 53.6 years), 35 (34%) were dippers. Although nondippers had similar BFV and cerebrovascular resistance (CVR) while supine, they had a lower BFV (P=.04) and greater CVR (P=.02) during head-up tilt compared with dippers. Moreover, greater nighttime dipping in both systolic BP (P=.006) and diastolic BP (P=.03) were associated with higher daytime BFV and lower CVR (P=.01 for systolic BP; P=.02 for diastolic BP). Inadequate nocturnal BP dipping is associated with lower daytime cerebral blood flow, especially during head-up tilt.

Studies on left ventricular hypertrophy regression in arterial hypertension: a clear message for the clinician?

BACKGROUND

Evidence-based medicine should provide clear and unbiased information to clinicians. We conducted an analysis on published randomized trials evaluating the effects of antihypertensive therapy on left ventricular (LV) morphology assessed by echocardiography to investigate (i) the consistency of criteria used for definition of LV hypertrophy (LVH) and (ii) the consistency of the way LVH regression and blood pressure (BP) control were reported.

METHODS

Studies identified by a PubMed search were eligible for inclusion in the analysis, if they fulfilled the following criteria: (i) publication in a peer-reviewed journal within the last 12 years; (ii) double blind, randomized, controlled, parallel-group design; (iii) numerosity of at least 50 adult hypertensive subjects; (iv) follow-up duration of at least 6 months; (v) comparison between single-drugs or association regimens; (vi) LV mass (LVM) or wall thickness measured by echocardiography.

RESULTS

Thirty-nine trials, including 9,162 hypertensive subjects of both genders in 78 active treatment arms or in 6 placebo arms were identified. Definition of LVH was provided by 34 studies (87.1%) according to 19 different criteria. All trials evaluated LVH regression as the absolute or relative changes of continuous variables such as LVM index (LVMI) or LV wall thickness. Data concerning prevalence rates of LVM normalization were reported in 12 studies (30.7%). The percentage of patients reaching BP target (<140/90 mm Hg) was reported in 11 studies (28.2%).

CONCLUSIONS

Our findings indicate that (i) definition of hypertensive LVH phenotype is extremely variable, and (ii) no precise information on LVH regression rates or changes in LV geometrical patterns, as well as on target BP, is provided by the majority of papers.

Establishing a new option for target-organ protection: rationale for ARB plus ACE inhibitor combination therapy

Activation of the renin-angiotensin system (RAS) plays an important role in the promotion of cardiovascular disease and target-organ damage, mediated in part by hypertension. Combination therapy targeting RAS activation may reduce target-organ damage and provide superior blood pressure (BP) control; combining angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) represents one possible approach. In monotherapy studies, both ACE inhibitors and ARBs have demonstrated similar positive effects on BP and on RAS-related target-organ damage, including nephropathy and congestive heart failure. Studies of combination therapy, most of which involved addition of an ARB to existing ACE inhibitor therapy, have demonstrated benefits among patients with congestive heart failure and renal disease. However, variances in study design and populations, dosing and titration methods, and clinical end points, in addition to inherent differences between agents, limit the ability to reach clinically meaningful conclusions about the value of dual RAS inhibition. Trials designed to document such efficacy are currently underway.

Angiotensin II and oxidative stress

PURPOSE OF REVIEW

Angiotensin II regulates vasoconstriction, homeostasis of salt and water, and cardiovascular hypertrophy and remodeling. Angiotensin II is a potent activator of NAD(P)H oxidase in the cardiovascular system, and augments production of reactive oxygen species. Numerous signaling pathways in response to angiotensin II are mediated by reactive oxygen species and oxidative stress is deeply associated with the progression of cardiovascular disease. The purpose of this review is to discuss the mechanism of reactive oxygen species formation and the pathophysiological effects of angiotensin II in the cardiovascular system.

RECENT FINDINGS

Recent studies have demonstrated novel molecular mechanisms of reactive oxygen species generation by angiotensin II and signaling pathways including cell proliferation, hypertrophy and apoptosis. In spite of these findings that strongly suggest the benefits of angiotensin II inhibition for cardiovascular disease, the clinical effects of angiotensin II-induced reactive oxygen species on the cardiovascular system are still controversial.

SUMMARY

We focus on the effects of angiotensin II-induced oxidative stress on cardiovascular function and remodeling after discussing the source of reactive oxygen species and novel signaling pathways in response to reactive oxygen species.

Angiotensin II receptor blockers and cardiovascular protection: focus on left ventricular hypertrophy regression and atrial fibrillation prevention

Left ventricular hypertrophy (LVH) and atrial fibrillation (AF) are strong predictors of cardiovascular (CV) morbidity and mortality, independently of blood pressure levels and other modifiable and nonmodifiable risk factors. The actions of circulating and tissue angiotensin II, mediated by AT1 receptors, play an important role in the development of a wide spectrum of cardiovascular alterations, including LVH, atrial enlargement and AF. Growing experimental and clinical evidence suggests that antihypertensive drugs may exert different effects on LVH regression and new onset AF in the setting of arterial hypertension. Since a number of large and adequately designed studies have found angiotensin II receptor blockers (ARBs) to be more effective in reducing LVH than beta-blockers and data are also available showing their effectiveness in preventing new or recurrent AF, it is reasonable to consider this class of drugs among first line therapies in patients with hypertension and LVH (a very high risk phenotype predisposing to AF) and as adjunctive therapy to antiarrhythmic agents in patients undergoing pharmacological or electrical cardioversion of AF.

Complications of hypertension and the role of angiotensin receptor blockers in hypertension trials

Hypertension is a high-prevalence disease that may affect several organs. In recent years, data have accumulated indicating that angiotensin II receptor blockers (ARBs) may have a supplementary effect beyond lowering blood pressure. The aim of this review is to evaluate the impact of ARBs on the most important complications of hypertension--heart, cerebrovascular and renal diseases, and metabolic complications--based on the findings from large clinical hypertension trials. The results may indicate that ARBs have a superior effect compared with placebo or other antihypertensive drugs in order to prevent left ventricular hypertrophy, atrial fibrillation, stroke, renal disease and diabetes mellitus, while there appears to be no blood pressure-independent superior effect of ARBs regarding prevention of myocardial infarction or heart failure.

Role of Angiotensin II in the Evolution of Diastolic Heart Failure

More than half of all persons with heart failure (HF) have diastolic HF. The prevalence of diastolic HF increases from 46% in persons younger than 45 years to 59% in those 85 years and older. The annual mortality rate associated with diastolic HF is >10%. Diagnosis is based on signs and symptoms of HF, elevated plasma B-type natriuretic peptide, preserved left ventricular systolic function, and evidence of diastolic dysfunction by Doppler examination on two-dimensional echocardiography. Approximately 80% of patients with diastolic HF have increased left ventricular mass and a history of hypertension. Neurohormonal activation is a key aspect of this condition. Studies suggest that activation of the renin-angiotensin-aldosterone system, specifically direct cardiac effects of angiotensin II and aldosterone, contributes to the pathogenesis and progression of diastolic dysfunction. Hence, there is a rationale for use of agents that antagonize the renin-angiotensin-aldosterone system, such as angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and aldosterone antagonists, in patients with heart failure.

Valsartan in a Japanese population with hypertension and other cardiovascular disease (Jikei Heart Study): a randomised, open-label, blinded endpoint morbidity-mortality study

BACKGROUND

Drugs that inhibit the renin-angiotensin-aldosterone system benefit patients at risk for or with existing cardiovascular disease. However, evidence for this effect in Asian populations is scarce. We aimed to investigate whether addition of an angiotensin receptor blocker, valsartan, to conventional cardiovascular treatment was effective in Japanese patients with cardiovascular disease.

METHODS

We initiated a multicentre, prospective, randomised controlled trial of 3081 Japanese patients, aged 20-79 years, (mean 65 [SD 10] years) who were undergoing conventional treatment for hypertension, coronary heart disease, heart failure, or a combination of these disorders. In addition to conventional treatment, patients were assigned either to valsartan (40-160 mg per day) or to other treatment without angiotensin receptor blockers. Our primary endpoint was a composite of cardiovascular morbidity and mortality. Analysis was by intention to treat. The study was registered at clintrials.gov with the identifier NCT00133328.

FINDINGS

After a median follow-up of 3.1 years (range 1-3.9) the primary endpoint was recorded in fewer individuals given valsartan than in controls (92 vs 149; absolute risk 21.3 vs 34.5 per 1000 patient years; hazard ratio 0.61, 95% CI 0.47-0.79, p=0.0002). This difference was mainly attributable to fewer incidences of stroke and transient ischaemic attack (29 vs 48; 0.60, 0.38-0.95, p=0.028), angina pectoris (19 vs 53; 0.35, 0.20-0.58, p<0.0001), and heart failure (19 vs 36; 0.53, 0.31-0.94, p=0.029) in those given valsartan than in the control group. Mortality or tolerability did not differ between groups.

INTERPRETATION

The addition of valsartan to conventional treatment prevented more cardiovascular events than supplementary conventional treatment. These benefits cannot be entirely explained by a difference in blood pressure control.

Amlodipine Added to Quinapril vs Quinapril Alone for the Treatment of Hypertension in Diabetes: The Amlodipine in Diabetes (ANDI) Trial

This randomized, comparative, parallel-group trial investigated strategies of blood pressure (BP)-lowering in patients with diabetes and hypertension. Patients not reaching goal BP (<130/80 mm Hg) after 4-week open-label treatment with quinapril 20 mg/d (n=374) received 40 mg/d quinapril (n=167) or 20 mg/d quinapril plus amlodipine besylate (5 mg/d; n=162) for 6 weeks. Patients receiving combination therapy vs monotherapy had significantly greater reductions in mean +/- SE sitting systolic BP (9.9+/-1.0 mm Hg vs 4.3+/-1.1 mm Hg; P<.001) and diastolic BP (6.5+/-0.6 mm Hg vs 2.7+/-0.6 mm Hg; P<.001). No significant differences between groups were observed in percentage of patients achieving goal BP (10.1% with combination therapy vs 8.2% with monotherapy). A clinically neutral effect was observed on high-sensitivity C-reactive protein in both groups. Treatments were well tolerated; fewer than 3% of patients in any group discontinued due to treatment-emergent or treatment-related adverse events. In diabetic hypertensive patients, 20 mg/d quinapril plus 5 mg/d amlodipine besylate was a more effective BP-lowering strategy than monotherapy with 40 mg/d quinapril.

Relationship between C-reactive protein levels and regional left ventricular function in asymptomatic individuals: the Multi-Ethnic Study of Atherosclerosis

OBJECTIVES

This study sought to investigate the relationship between C-reactive protein (CRP) and regional left ventricular (LV) function in asymptomatic individuals without a history of cardiovascular disease.

BACKGROUND

C-reactive protein is associated with an increased risk for developing cardiovascular disease. However, the relationship between CRP and subclinical LV dysfunction has not been evaluated in asymptomatic individuals.

METHODS

Regional myocardial function was analyzed as peak systolic circumferential shortening strain (Ecc) using the harmonic-phase method by tagged magnetic resonance imaging in 1,164 individuals without symptomatic cardiovascular disease from the MESA (Multi-Ethnic Study of Atherosclerosis) trial (age 66.4 +/- 9.6 years old). Regions were defined by coronary territories: left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA). The relationship between log-CRP concentration and Ecc was studied by multivariable linear regression after adjustment for demographic characteristics, risk factors, and therapy (including hormone replacement therapy).

RESULTS

For each region, associations differed by gender with no association of CRP and regional LV function among women. In men, after adjustment, higher log-CRP was significantly associated with lower (absolute) Ecc in the LAD and RCA regions (regression coefficient 0.37 per unit higher log-CRP [95% confidence interval [CI] 0.08 to 0.65] and 0.31 [95% CI 0.02 to 0.59], respectively) and peak systolic Ecc overall (regression coefficient 0.32 [95% CI 0.05 to 0.58]). In the LCX region, the association was weaker (p = 0.06).

CONCLUSIONS

Among individuals without evident heart failure or other cardiovascular disorders, higher CRP was associated with lower systolic myocardial function in all regions in men but not in women. These findings support the role of inflammation and atherosclerosis in incipient myocardial dysfunction. (Multi-Ethnic Study of Atherosclerosis; http://clinicaltrials.gov/ct/show/NCT00005487).

C-reactive protein (CRP)-lowering agents

C-reactive protein (CRP) plays a role in the pathogenesis of cardiovascular disease. It is a marker and predictor of cardiovascular disease. CRP possesses numerous cardiovascular effects (clotting, generation of oxygen radicals, increase in the expression of adhesion molecules and plasminogen activator inhibitor-1, plaque destabilization) that could result in cardiovascular disease. This review describes the effects of various cardiovascular drugs on the levels of CRP in health and disease. Cyclooxygenase inhibitors (aspirin, rofecoxib, celecoxib), platelet aggregation inhibitors (clopidogrel, abciximab), lipid lowering agents (statins, ezetimibe, fenofibrate, niacin, diets), beta-adrenoreceptor antagonists and antioxidants (vitamin E), as well as angiotensin converting enzyme (ACE) inhibitors (ramipril, captopril, fosinopril), reduce serum levels of CRP; while enalapril and trandolapril have not been shown to have the same effect. Angiotensin receptor blockers (ARBs) (valsartan, irbesartan, olmesartan, telmisartan) markedly reduce serum levels of CRP. The findings with other ARBs (losartan and candesartan) were inconsistent. Antidiabetic agents (rosiglitazone and pioglitazone) reduce CRP levels, while insulin is ineffective. Calcium channel antagonists have variable effects on CRP levels. Hydrochlorothiazide and oral estrogen do not affect CRP. The CRP-lowering effect of statins is more pronounced than their lipid lowering effect and is not dependent on their hypolipemic activity. The effect of atorvastatin on CRP seems to be dose-dependent. CRP-lowering effect of statins is likely to contribute to the favorable outcome of statin therapy. The data suggest that lipid lowering agents, ACE inhibitors, ARBs, antidiabetic agents, antiinflammatory and antiplatelet agents, vitamin E, and beta-adrenoreceptor antagonists lower serum or plasma levels of CRP, while vitamin C, oral estrogen and hydrochlorothiazide do not affect CRP levels.

Carotid artery intima-media thickness and reactive oxygen species formation by monocytes in hypertensive patients

Carotid artery intima-media thickness (IMT) is a widely accepted index for assessing atherosclerosis, and is known to be a risk indicator for cardiovascular and cerebrovascular events. Oxidative stress and inflammation are also known to play critical roles in the pathogenesis of vascular events. We studied the association between IMT and inflammatory markers, such as oxidative stress in polymorphonuclear leukocytes (PMNs) and mononuclear cells (MNCs) in 156 patients with essential hypertension. Reactive oxygen species (ROS) formation by PMNs and MNCs was measured by gated flow cytometry. CRP and traditional risk factors, such as age, gender, body mass index, hemoglobin A(1c), and total cholesterol were also measured. The subjects were divided into a plaque group (max-IMT>or=1.1 mm, n=40), and a nonplaque group (max-IMT<1.1 mm, n=116). ROS formation by MNCs was significantly increased in the plaque group when compared with the nonplaque group (P<0.0001). Multiple regression analysis revealed a significant correlation between IMT and ROS formation by MNCs (r=0.407, P<0.0001), or CRP (r=0.216, P=0.0029) or hemoglobinA1c (r=0.158, P=0.0270) or age (r=0.157, P=0.0447). No significant correlation was observed between IMT and ROS formation by PMNs. These results suggest that carotid artery IMT may be affected by increased ROS formation by MNCs, and that increased ROS formation by MNCs may be related to the development of atherosclerosis. We propose that ROS formation by MNCs is a marker for prediction of carotid atherosclerosis.

Angiotensin-converting enzyme inhibition reduces lipid deposits in myocardium and improves left ventricular function of obese zucker rats

OBJECTIVE

Alterations in the renin angiotensin system, cardiac lipotoxicity, and left ventricular (LV) dysfunction have been reported in obese rats. The present study examined whether angiotensin-converting enzyme inhibition could ameliorate lipid deposition and ventricular function in the myocardium of obese Zucker rats (OZRs).

RESEARCH METHODS AND PROCEDURES

For 6 months, rats were treated as follows: Group (G) 1, OZR, no treatment; G2, OZR + ramipril (R); G3, OZR + amlodipine (AML); and G4, lean Zucker rats. LV function was assessed by echocardiogram and lipid deposits in cardiomyocytes (LDCM) by light microscopy using Oil red O.

RESULTS

At the end of the experiment, both OZR + R and OZR + AML groups presented similar reduction in blood pressure in comparison with untreated OZR (p < 0.01). OZR with R presented lower insulin-to-glucose ratio and lower serum triglycerides and cholesterol when compared with both untreated OZR and OZR with AML (p < 0.01). Fractional shortening by echocardiogram was as follows: G1, 25.4 +/- 3.8 (vs. G2 and G4, p < 0.05); G2, 37.2 +/- 2.4; G3, 29.3 +/- 4.4 (vs. G2 and G4, p < 0.05); and G4, 40.8 +/- 2.3. Percentage LDCM was as follows: G1, 12.4 +/- 2.7 (vs. G2 and G4, p < 0.05); G2, 0.8 +/- 0.2; G3, 11.1 +/- 2.1 (vs. G2 and G4, p < 0.05); and G4, 0.1 +/- 0.1. There was a negative correlation between fractional shortening and LDCM percentage in OZR (r = -0.93) and in OZR + AML (r = -0.87).

DISCUSSION

AML reduced blood pressure significantly; however, it failed to modify both metabolic parameters and LDCM. In contrast, R showed a substantial reduction in LDCM, together with LV function preservation.

Mechanism of Angiotensin II Type 1 Receptor Blocker Action in the Regression of Left Ventricular Hypertrophy

Left ventricular hypertrophy refers to a pathologic increase in left ventricular mass and is associated with an increased risk of subsequent cardiovascular morbidity and mortality from any cause. In the development of left ventricular hypertrophy there is growth of cardiomyocytes and accumulation of extracellular matrix and fibrosis. The actions are partly induced by angiotensin II, the principal effector of the renin-angiotensin-aldosterone system, binding to the AT1 receptor. Biochemical markers, some implicated in inflammatory changes, correlate with changes in left ventricular mass. The reduction in left ventricular mass brought about with angiotensin-converting enzyme inhibitor or angiotensin receptor blocker (ARB) therapy correlates with a reduction in these inflammatory changes, monitored by brain natriuretic peptide. Recent studies incorporating trials of ARBs have found ARBs to be more effective in reducing left ventricular mass than beta blockers and possibly more effective than calcium antagonists. Initial studies suggest that ARBs and angiotensin-converting enzyme inhibitors may have similar effects in terms of reducing left ventricular hypertrophy, and the combination of angiotensin-converting enzyme inhibitors and ARBs is thought to be synergistic due to a more complete inhibition of the renin-angiotensin-aldosterone system. In conclusion, these agents are efficacious in antihypertensive therapy and can play an important role in the prevention or regression of left ventricular hypertrophy due to hypertension.

Effects of amlodipine and valsartan on vascular damage and ambulatory blood pressure in untreated hypertensive patients

The present study was performed to compare the long-term effects of 24-h ambulatory blood pressure (BP) control with amlodipine versus valsartan on vascular damage in untreated hypertensive patients. Amlodipine and valsartan have benefits on cardiovascular mortality and morbidity in hypertensive patients. Although ambulatory BP is associated with severity of target-organ damage in hypertensive patients, beneficial effects of ambulatory BP control with amlodipine versus valsartan on vascular damage have not been compared. Pulse wave velocity (PWV), intima-media thickness (IMT) of the carotid arteries, urinary albumin excretion (UAE) and 24-h ambulatory BP were determined in 100 untreated hypertensive patients before and 12 months after the start of antihypertensive therapy with amlodipine or valsartan. Amlodipine and valsartan decreased ambulatory BP similarly, but the variability of 24-h and daytime ambulatory systolic BP was significantly reduced by amlodipine but not by valsartan. The reduced variability of ambulatory systolic BP caused by amlodipine significantly contributed to the improvement of PWV, although both drugs decreased PWV similarly. Carotid IMT was unaffected by treatment with either drug. Valsartan significantly decreased UAE independently of its depressor effect, but amlodipine had no effect on UAE. These results suggest that the 24-h control of ambulatory BP with amlodipine had functionally improved the stiffened arteries of hypertensive patients by the end of 12 months of treatment, in part through reducing BP variability, whereas ambulatory BP control with valsartan decreased the arterial stiffness to the same degree as amlodipine without affecting BP variability maybe through some pleiotropic effects.

Candesartan, an angiotensin II type-1 receptor blocker, reduces cardiovascular events in patients on chronic haemodialysis--a randomized study

BACKGROUND

Cardiovascular events are the major determinants of the prognosis of patients on chronic haemodialysis. The present study was designed to investigate whether candesartan, an angiotensin II type-1 receptor blocker, reduces the incidence of cardiovascular events in these patients.

METHODS

A total of 80 chronic haemodialysis patients (male/female, 47/33; mean age +/- SEM, 61 +/- 1 years) in stable condition and with no clinical evidence of cardiac disorders were enrolled. Patients were randomly assigned candesartan 4-8 mg/day (candesartan group; n = 43) or nothing (control group; n = 37), and followed for 19.4 +/- 1.2 months with as endpoint cardiovascular events such as fatal/nonfatal myocardial infarction, unstable angina pectoris, congestive heart failure, severe arrhythmia and sudden death.

RESULTS

Both groups exhibited similar clinical characteristics at baseline. During follow-up, cardiovascular events occurred in seven patients in the candesartan group and 17 in the control group. Kaplan-Meier analysis revealed that cardiovascular events and mortality rates were significantly (P < 0.01) higher in the control group than in the candesartan group (45.9 vs 16.3% and 18.9 vs 0.0%, respectively).

CONCLUSIONS

Candesartan therapy significantly reduces cardiovascular events and mortality in patients on chronic maintenance haemodialysis and therefore improves the prognosis of these patients.

Valsartan improves resting skin blood flow in type 2 diabetic patients and reduces poly(adenosine diphosphate-ribose) polymerase activation

OBJECTIVE

To examine the effect of a 12-week daily treatment with 160 mg of valsartan, an angiotensin II receptor blocker, on the microcirculation and macrocirculation of type 2 diabetic patients (T2DM) and healthy subjects.

METHODS

This was a prospective, randomized, double-blind, placebo-controlled crossover study. Thirteen T2DM with no severe complications and 13 healthy subjects completed the trial.

RESULTS

Treatment with valsartan in T2DM improved the resting forearm skin blood flow and increased the resting brachial artery diameter but had no effects on arterial blood pressure, large vessel vascular reactivity, or carotid intima-media thickness. Resting skin blood flow increased by 60% (2%-90%; median and 25th-75th percentiles) during valsartan treatment and by only 2% (-22% to 27%) during placebo treatment (P < .05). No changes were observed in the nondiabetic subjects. Immunostaining studies of forearm skin biopsy samples from T2DM and healthy subjects showed that valsartan reduced poly(adenosine diphosphate-ribose) polymerase (PARP) activity in 50% (6/12) of the subjects. PARP activity remained unchanged in placebo-treated subjects (P < .02). In addition, valsartan treatment increased CD31 staining in 33% (4/12) of the subjects, whereas no change was noted in sequential skin biopsy samples of placebo-treated subjects (P = .057). Valsartan had no effect on the biochemical markers of endothelial cell activation and other cytokines, including CAMs, interleukin 6, tumor necrosis factor alpha, C-reactive protein, adiponectin, and plasma activator inhibitor 1.

CONCLUSIONS

Valsartan increases the resting skin blood flow in T2DM, likely through reduction of PARP activity.

Vascular and metabolic effects of candesartan: insights from therapeutic interventions

BACKGROUND

Effects of angiotensin II type 1 receptor blockers (ARBs) to improve endothelial dysfunction may be due to mechanisms in addition to the reduction of high blood pressure per se. Endothelial dysfunction is characterized by vascular inflammation that contributes to clinically significant atherosclerosis and by an increased tendency for thrombus formation. Hypertensive patients have impaired endothelial functions that have positive predictive power with respect to future cardiovascular events.

OBJECTIVES

The present review will focus on multiple mechanisms underlying vascular and metabolic effects of ARBs that may synergize to prevent or regress atherosclerosis, onset of diabetes, and coronary heart disease.

CONCLUSIONS

Angiotensin II accelerates the development of atherosclerosis by activating angiotensin II type 1 receptors that then promote superoxide anion generation and oxidative stress, leading to activation of nuclear transcription factor and endothelial dysfunction. Activation of angiotensin II type 1 receptors also stimulates increased expression of plasminogen activator inhibitor type 1 and tissue factor. Endothelial dysfunction associated with the metabolic syndrome and other insulin-resistant states is characterized by impaired insulin-stimulated production of nitric oxide from the endothelium and decreased blood flow to skeletal muscle. Increasing insulin sensitivity therefore improves endothelial function, and this may be an additional mechanism whereby ARBs decrease the incidence of coronary heart disease and the onset of diabetes. Adiponectin serves to link obesity with insulin resistance. In addition, adiponectin has anti-atherogenic properties.

The Long-Term Behavior and Predictors of Left Ventricular Hypertrophy in Hemodialysis Patients

BACKGROUND

The long-term behavior of left ventricular hypertrophy (LVH) was evaluated and potential predictors of change in left ventricular mass index (LVMI) in hemodialysis (HD) patients were determined.

METHODS

One hundred eight patients on regular HD treatment were included. In addition to hematologic and biochemical evaluations, annual echocardiography and 24-hour ambulatory blood pressure monitoring were performed in all patients. During the median follow-up of 50 months (range, 12 to 63 months), a median of 4 echocardiographic examinations were performed in each patient. The presence of LVH was defined on the basis of an LVMI greater than 131 g/m2 for men and greater than 100 g/m2 for women.

RESULTS

Eighty-two patients (75.9%) had LVH at baseline. LVH status was stable in 64 patients, whereas it changed on at least 1 occasion in the remaining patients (40.7%). LVH disappeared during the first year in 8 patients and beyond the first year of dialysis therapy in an additional 9 patients. An 8.0 +/- 39.6-g/m2 decrease in LVMI was detected between the first and final evaluations. Independent predictors of change in LVMI were C-reactive protein level (P < 0.001), baseline hemoglobin level (P = 0.025), and baseline postdialysis systolic blood pressure (P = 0.003). Twenty-four-hour systolic blood pressure was the only independent predictor of both LVMI (P < 0.001) and LVH (P = 0.001) at baseline. Nighttime systolic blood pressure and C-reactive protein level were found to be independent predictors of final LVMI (P < 0.001 for both). Independent predictors of LVH at the end of the study were 24-hour systolic blood pressure (P = 0.022) and C-reactive protein level (P = 0.003), whereas hemoglobin level had marginal significance (P = 0.051).

CONCLUSION

Progressive LVH is not inevitable in HD patients. Aggressive treatment against the predictors may result in regression of LVMI and may improve patient outcome.

Valsartan/Hydrochlorothiazide

Valsartan/hydrochlorothiazide is a fixed-dose (valsartan 80, 160 or 320mg plus hydrochlorothiazide 12.5 or 25mg) angiotensin II receptor blocker/diuretic drug combination indicated for the treatment of patients with essential hypertension not adequately controlled by monotherapy.There is ample evidence that valsartan/hydrochlorothiazide is an effective fixed-dose combination antihypertensive agent. However, efficacy and tolerability data pertaining to the 320mg dose of valsartan in the combination are currently relatively few. There is also some evidence of potential benefits associated with the relatively favourable tolerability profile of the combination, the low occurrence of new-onset diabetes mellitus versus amlodipine and the valsartan-associated improvements in cardiac and endothelial function.

Valsartan inhibits platelet activity at different doses in mild to moderate hypertensives: Valsartan Inhibits Platelets (VIP) trial

BACKGROUND

Previous in vitro studies have suggested that valsartan produces significant inhibition of human platelets, probably targeting angiotensin I platelet receptors. To test whether valsartan inhibits platelet activity in mild to moderate hypertensives we conducted the randomized Valsartan Inhibits Platelets (VIP) trial.

METHODS AND RESULTS

Seventy-five patients with mild to moderate hypertension were randomized to valsartan 80 (n = 25), valsartan 160 (n = 29), or valsartan 320 mg/d (n = 21) for 9 weeks. Platelet function was assessed at baseline, week 5, and week 9 by aggregometry, flow cytometry, and cartridge-based analyzer. Independently of dose and duration, valsartan provided early sustained significant inhibition of adenosine diphosphate-induced platelet aggregation, decreased shear-induced activation measured with PFA-100 analyzer, and diminished expression of GP IIb/IIIa activity measured by PAC-1 antibody, GPIb (CD42b), vitronectin receptor (CD51/61), P-selectin (CD62p), lysosome-associated membrane protein (CD107a), and CD40-ligand (CD154). The antiplatelet properties of valsartan were more profound in patients with diabetes (n = 28) when compared with the nondiabetic group (n = 47). In subgroup analyses of patients with diabetes there appeared to be stronger inhibition of the platelet receptors, a significant decrease of adenosine diphosphate- and collagen-induced platelet aggregation, and more profound inhibition of GP IIb/IIIa activity.

CONCLUSIONS

In the randomized VIP trial, valsartan produced sustained inhibition of platelet aggregation and major platelet receptors. The antiplatelet properties of valsartan were not dose or time dependent. In subgroup analyses patients with diabetes with mild to moderate hypertension tended to have greater platelet inhibition, a finding which, if confirmed in future studies suggests possible additional advantages for using valsartan in this high-risk population.

Effects of Angiotensin II Receptor Blockade with Valsartan on Pro-Inflammatory Cytokines in Patients with Essential Hypertension

Chronic inflammation is common in hypertension and acts as an independent determinant of arterial blood pressure. Hypertensive patients are reported to have high circulating levels of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and C-reactive protein (CRP). Recently, angiotensin II receptor blockers (ARBs) have been shown to possess benefits in addition to their ability to lower blood pressure, including anti-inflammatory and antioxidative properties within the vasculature. We evaluated the effects of the angiotensin II receptor blocker, valsartan, on these inflammatory cytokines. Thirty-nine patients with essential hypertension participated. These subjects received valsartan, 40 to 80 mg/day. Serum TNF-alpha, IL-6, CRP, and serum amyloid A (SAA) were measured before and after 3 months of treatment with valsartan. Valsartan significantly decreased systolic and diastolic blood pressure (160 +/- 16/92 +/- 11 mm Hg to 147 +/- 21/84 +/- 11 mm Hg, P = 0.001/P = 0.001, respectively). Serum TNF-alpha (9.1 +/- 8.6 pg/mL to 6.1 +/- 1.0 pg/mL, P = 0.006) and IL-6 (9.3 +/- 1.7 pg/mL to 8.9 +/- 1.4 pg/mL, P = 0.005) were significantly reduced after treatment with valsartan. However, C-reactive protein and serum amyloid A did not change. The angiotensin II receptor blocker, valsartan, may inhibit the development of atherosclerosis by lowering serum pro-inflammatory cytokines.

Efficacy and tolerability of combination therapy with valsartan plus hydrochlorothiazide compared with amlodipine monotherapy in hypertensive patients with other cardiovascular risk factors: The VAST study

BACKGROUND

Recent antihypertensive treatment guidelines recommend greater use of combination therapies.

OBJECTIVES

The primary objective of this study was to determine whether combination therapy with valsartan 160 mg plus hydrochlorothiazide (HCTZ) 25 mg OD would be more effective than monotherapy with amlodipine 10 mg OD in reducing systolic blood pressure (SBP) in patients with moderate (stage II) hypertension and > or =1 other cardiovascular risk factor or concomitant condition. A secondary objective was to assess the effects of the study treatments on circulating markers of endothelial dysfunction and vascular inflammation.

METHODS

This was a multicenter, randomized, double-blind, active-controlled, 24-week study. After a 2-week, single-blind, placebo run-in period, patients were randomized to 3 groups, 2 of them receiving valsartan 160 mg OD and 1 receiving amlodipine 5 mg OD. At week 4, HCTZ 12.5 mg OD was added to valsartan in one of the treatment groups (V+HCTZ12.5), HCTZ 25 mg OD was added to the other (V+HCTZ25), and the amlodipine dose was force-titrated to 10 mg OD (A10). The primary efficacy variable was change in mean sitting SBP at week 24. Other variables were changes in mean sitting diastolic blood pressure (DBP) and mean pulse pressure (PP) from baseline, and response rate (systolic response defined as mean sitting SBP <140 mm Hg or a reduction in mean sitting SBP of > or =20 mm Hg from baseline; diastolic response defined as mean sitting DBP <90 mm Hg or a reduction in mean sitting DBP of > or =10 mm Hg from baseline). Changes in the following markers of endothelial dysfunction were determined at baseline and weeks 4, 12, and 24 in all randomized patients from the participating European and South African centers: high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), vascular tissue plasminogen activator (t-PA) antigen, and oxidized low-density lipoprotein (LDL).

RESULTS

The study enrolled 1088 patients with moderate hypertension (mean age, 61 years; 82% white; 53% women). The intent-to-treat population consisted of 1079 patients: 357 in the V+HCTZ12.5 group, 363 in the V+HCTZ25 group, and 359 in the A10 group. At baseline, the groups were comparable in terms of blood pressure and most other characteristics; the only statistically significant difference between groups was in the proportion of patients aged > or =65 years, which was lower in the amlodipine group (P = 0.01). At the end of the study, the least squares mean (SD) changes from baseline in mean sitting SBP were 27.1 (13.7), 29.7 (13.7), and 27.6 (13.8) mm Hg in the V+HCTZ12.5, V+HCTZ25, and A10 groups, respectively, with corresponding percent changes of 16%, 18%, and 17% (P < 0.05, V+HCTZ25 vs A10). The changes in mean sitting DBP did not differ significantly between groups. The reductions in PP were 17.5 (11.3), 18.7 (11.3), and 16.9 (11.3) mm Hg, with percent changes of 24%, 26%, and 23% (P < 0.05, V+HCTZ25 vs A10). Significant reductions in t-PA antigen were observed in both combination-therapy groups compared with the amlodipine monotherapy group at week 12 (P < 0.05); the reductions remained significant through the end of the study in the V+HCTZ12.5 group. There was a significant reduction in IL-6 and hs-CRP at week 12 with V+HCTZ25 compared with A10 (P < 0.05). Oxidized LDL values were reduced by approximately 10% with all treatments. Rates of total adverse events were significantly lower with the valsartan-based treatments compared with amlodipine monotherapy (49.7%, 49.6%, and 67.5% with V+HCTZ12.5, V+HCTZ25, and A10, respectively; P < 0.05). Rates of total discontinuations were a respective 10.1%, 9.0%, and 24.5%, and discontinuation rates due to AEs were 4.2%, 3.5%, and 18.2%. Leg edema was more common with amlodipine monotherapy than with the valsartan-based combinations (P < 0.05).

CONCLUSION

In this group of patients with moderate hypertension and > or =1 other cardiovascular risk factor or concomitant condition, similar and greater antihypertensive effects were seen with the fixed-dose combinations of valsartan 160 mg and HCTZ 12.5 and 25 mg OD, respectively, compared with amlodipine 10 mg OD, with significantly lower rates of treatment-related adverse events and possible beneficial effects on vascular markers.