Angiotensin II type 1 receptor antagonists in animal models of vascular, cardiac, metabolic and renal disease.

We have reviewed the effects of angiotensin II type 1 receptor antagonists (ARBs) in various animal models of hypertension, atherosclerosis, cardiac function, hypertrophy and fibrosis, glucose and lipid metabolism, and renal function and morphology. Those of azilsartan and telmisartan have been included comprehensively whereas those of other ARBs have been included systematically but without intention of completeness. ARBs as a class lower blood pressure in established hypertension and prevent hypertension development in all applicable animal models except those with a markedly suppressed renin-angiotensin system; blood pressure lowering even persists for a considerable time after discontinuation of treatment. This translates into a reduced mortality, particularly in models exhibiting marked hypertension. The retrieved data on vascular, cardiac and renal function and morphology as well as on glucose and lipid metabolism are discussed to address three main questions: 1. Can ARB effects on blood vessels, heart, kidney and metabolic function be explained by blood pressure lowering alone or are they additionally directly related to blockade of the renin-angiotensin system? 2. Are they shared by other inhibitors of the renin-angiotensin system, e.g. angiotensin converting enzyme inhibitors? 3. Are some effects specific for one or more compounds within the ARB class? Taken together these data profile ARBs as a drug class with unique properties that have beneficial effects far beyond those on blood pressure reduction and, in some cases distinct from those of angiotensin converting enzyme inhibitors. The clinical relevance of angiotensin receptor-independent effects of some ARBs remains to be determined.

Aldosterone synthase inhibition for the treatment of hypertension and the derived mechanistic requirements for a new therapeutic strategy.

CONTEXT: We describe the clinical investigation of the first generation aldosterone synthase inhibitor, LCI699, in patients with essential, uncontrolled, resistant, or secondary hypertension. LCI699 competitively reduced blood pressure at lower doses yet counterintuitive effects were observed at higher doses. OBJECTIVE AND METHOD: An extensive endocrine biomarker analysis was performed to better understand the pharmacological mechanism of the drug. RESULTS: The interference of LCI699 in the renin-angiotensin-aldosterone system occurred with limited target selectivity, as a dose-dependent compensatory stimulation of the hypothalamic-pituitary-adrenal feedback axis was discovered. Thus, LCI699 affected two endocrine feedback loops that converged at a single point, inhibiting the 11ß-hydroxylase reaction in the adrenal gland, leading to supraphysiological levels of 11-deoxycortiscosterone. The accumulation of this potent mineralocorticoid may explain the blunted blood pressure response to LCI699. CONCLUSION: Future aldosterone synthase inhibitors may improve their target selectivity by sparing the 11ß-hydroxylase reaction and preferentially inhibiting one of the two other enzymatic reactions mediated by aldosterone synthase.

A systematic comparison of the properties of clinically used angiotensin II type 1 receptor antagonists.

Angiotensin II type 1 receptor antagonists (ARBs) have become an important drug class in the treatment of hypertension and heart failure and the protection from diabetic nephropathy. Eight ARBs are clinically available [azilsartan, candesartan, eprosartan, irbesartan, losartan, olmesartan, telmisartan, valsartan]. Azilsartan (in some countries), candesartan, and olmesartan are orally administered as prodrugs, whereas the blocking action of some is mediated through active metabolites. On the basis of their chemical structures, ARBs use different binding pockets in the receptor, which are associated with differences in dissociation times and, in most cases, apparently insurmountable antagonism. The physicochemical differences between ARBs also manifest in different tissue penetration, including passage through the blood-brain barrier. Differences in binding mode and tissue penetration are also associated with differences in pharmacokinetic profile, particularly duration of action. Although generally highly specific for angiotensin II type 1 receptors, some ARBs, particularly telmisartan, are partial agonists at peroxisome proliferator-activated receptor-γ. All of these properties are comprehensively reviewed in this article. Although there is general consensus that a continuous receptor blockade over a 24-hour period is desirable, the clinical relevance of other pharmacological differences between individual ARBs remains to be assessed.

Cardiovascular outcomes in hypertensive patients: comparing single-agent therapy with combination therapy.

OBJECTIVES: To determine whether blood pressure (BP) control in hypertensive patients achieved with combination drug therapy provides the same cardiovascular benefits as with single-agent therapy. BACKGROUND: Drug combinations, most often including hydrochlorothiazide (HCTZ), are now recommended for routine BP management, but their effects on cardiovascular event rates have not been compared with effective monotherapy. METHODS: We conducted retrospective analyses of the Valsartan Antihypertensive Long-term Use Evaluation (VALUE) data. VALUE compared cardiovascular event rates of valsartan and amlodipine. Patients with BPs not controlled (<140/90  mmHg) by the single agents had HCTZ and, if required, additional drugs of different classes, added. Using data pooled from the two treatment arms, we have now divided patients into those controlled on monotherapy and those controlled or not controlled by combination therapy. The primary study endpoint was first occurrence of cardiovascular death or nonfatal myocardial infarction or stroke. Comparisons between groups were by Cox regression, adjusted for on-treatment BP, age, prior cardiovascular events and left ventricular hypertrophy; the comparison between the monotherapy and combination therapy controlled groups was based on events occurring after 3 months by when the decision to use monotherapy or combination therapy was made. RESULTS: The primary endpoint occurred in 505 of 5924 (8.5%) monotherapy and 511 of 4621 (11.1%) combination therapy controlled patients: hazard ratio was 0.80 [95% confidence interval (CI) 0.70-0.90]. If these two groups were matched for baseline BPs and all events included from study baseline, the hazard ratio was 0.76 (95% CI 0.67-0.86). The difference between combination controlled and uncontrolled [434 of 3390 (12.8%)] groups was not significant [hazard ratio 0.90 (95% CI 0.80-1.03], nor when they were matched for baseline BPs [hazard ratio 0.95 (95% CI 0.81-1.11)]. CONCLUSION: Independent of prior cardiovascular history or baseline BP, hypertensive patients requiring combination therapy, which includes a thiazide diuretic for BP control, have a poorer cardiovascular prognosis than those controlled by monotherapy and only a nonsignificantly lower event rate than noncontrolled patients.

Usefulness of heart rate to predict cardiac events in treated patients with high-risk systemic hypertension.

A high heart rate (HR) predicts future cardiovascular events. We explored the predictive value of HR in patients with high-risk hypertension and examined whether blood pressure reduction modifies this association. The participants were 15,193 patients with hypertension enrolled in the Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial and followed up for 5 years. The HR was assessed from electrocardiographic recordings obtained annually throughout the study period. The primary end point was the interval to cardiac events. After adjustment for confounders, the hazard ratio of the composite cardiac primary end point for a 10-beats/min of the baseline HR increment was 1.16 (95% confidence interval 1.12 to 1.20). Compared to the lowest HR quintile, the adjusted hazard ratio in the highest quintile was 1.73 (95% confidence interval 1.46 to 2.04). Compared to the pooled lower quintiles of baseline HR, the annual incidence of primary end point in the top baseline quintile was greater in each of the 5 study years (all p <0.05). The adjusted hazard ratio for the primary end point in the highest in-trial HR heart rate quintile versus the lowest quintile was 1.53 (95% confidence interval 1.26 to 1.85). The incidence of primary end points in the highest in-trial HR group compared to the pooled 4 lower quintiles was 53% greater in patients with well-controlled blood pressure (p <0.001) and 34% greater in those with uncontrolled blood pressure (p = 0.002). In conclusion, an increased HR is a long-term predictor of cardiovascular events in patients with high-risk hypertension. This effect was not modified by good blood pressure control. It is not yet known whether a therapeutic reduction of HR would improve cardiovascular prognosis.

Practical solutions to the challenges of uncontrolled hypertension: a white paper.

This white paper is an urgent call to action from an international group of physicians. The continued failure to control hypertension takes an unacceptable toll on patients, families and society and it must be addressed. Any patient with blood pressure of 140/90 mmHg or greater can be characterized as a 'challenging patient', is at significant risk, and requires persistent optimization of therapy until target blood pressure is achieved. Six key challenges in reaching this goal blood pressure are described: (1) inadequate primary prevention; (2) faulty awareness of risk; (3) lack of simplicity; (4) therapeutic inertia; (5) insufficient patient empowerment; and (6) unsupportive healthcare systems. This white paper identifies straightforward actions that will produce rapid improvements in the management of hypertension, with a simple aim: to treat all challenging patients effectively to goal blood pressure, preventing disability and saving lives.

Under pressure: future prospects in hypertension management. Interview by Laura Dormer.

Professor Hans Rudolf Brunner Born in 1937, Professor Brunner is a Swiss citizen. He is a Professor Emeritus of Medicine at the University of Lausanne, Switzerland. He has been at the forefront of research on the role of renin and the renin-angiotensin system in blood pressure regulation. He has been involved in the development of drugs such as angiotensin-converting enzyme inhibitors and angiotensin receptor blockers. He was among the first medical practitioners to introduce the use of angiotensin-converting enzyme inhibitors in the treatment of hypertension and congestive heart failure. Professor Brunner has been a medical advisor to Speedel since 1999.

Antihypertensive efficacy of olmesartan medoxomil and candesartan cilexetil in achieving 24-hour blood pressure reductions and ambulatory blood pressure goals.

BACKGROUND: For patients with hypertension, effective 24-hour blood pressure (BP) control is vital to ensure protection against the early morning surge in BP and the associated increased risk of cardiovascular events. The aim of this analysis was to assess the 24-hour antihypertensive efficacy of olmesartan medoxomil (20mg once daily) compared with candesartan cilexetil (8mg once daily), with particular emphasis on BP control during the early morning period. METHODS: This is an additional analysis of a previously reported randomised, double-blind study in which 635 patients with mainly mild to moderate hypertension were randomised to 8 weeks of treatment with either olmesartan medoxomil 20 mg/day or candesartan cilexetil 8 mg/day. Changes from baseline during the last 4 and 2 hours of ambulatory BP measurement (ABPM) after 1, 2 and 8 weeks of treatment were compared between the two groups. In addition, the proportions of patients who achieved various ABPM goals, including those suggested by the European Society of Hypertension/European Society of Cardiology (ESH/ESC) [<125/80mm Hg] and the Japanese Society of Hypertension (JSH) [<135/80mm Hg], over 24 hours, during the daytime and at the last 4 and 2 hours of ABPM measurement were also compared. RESULTS: After 8 weeks, significantly greater proportions of patients treated with olmesartan medoxomil 20mg achieved 24-hour and daytime ABPM goals recommended by the guidelines of the ESH/ESC (25.6% and 18.3%, respectively) and JSH (37.5% and 26.6%, respectively) compared with candesartan cilexetil 8mg (24-hour ESH/ESC goal = 14.9%, p < 0.001; 24-hour JSH goal = 26.6%, p = 0.003; daytime ESH/ESC goal = 9.6%, p = 0.002; daytime JSH goal = 16.4%, p = 0.002). During the last 4 hours of 24-hour ABPM, the proportions of patients who achieved the ESH/ESC and JSH ABPM goals were significantly greater with olmesartan medoxomil (33.3% and 39.1%, respectively) than with candesartan cilexetil (22.9%, p < 0.001 and 31.6%, p = 0.047, respectively). Similarly, during the last 2 hours of 24-hour ABPM, the proportions of patients who achieved these BP goals were either significantly greater (JSH) or approached statistical significance (ESH/ESC) with olmesartan medoxomil (26.9% and 19.9%, respectively) compared with candesartan cilexetil (19.6%, p = 0.028 and 14.3%, p = 0.061, respectively). CONCLUSION: Compared with candesartan cilexetil 8mg, greater proportions of olmesartan medoxomil-treated patients (20mg) achieved ESH/ESC and JSH ABPM goals over 24 hours. The superior BP control of olmesartan medoxomil was also reflected in the larger proportions of olmesartan medoxomil-treated patients who achieved the ESH/ESC and JSH ABPM goals during the early morning surge period. This not only demonstrates that olmesartan medoxomil 20mg provides superior 24-hour BP reduction, but also suggests that olmesartan medoxomil may provide greater protection against the increased risk of cardiovascular events associated with the early morning BP surge period.

The Valsartan Antihypertensive Long-Term Use Evaluation (VALUE) trial: outcomes in patients receiving monotherapy.

In the main Valsartan Antihypertensive Long-Term Use Evaluation (VALUE) report, we investigated outcomes in 15 245 high-risk hypertensive subjects treated with valsartan- or amlodipine-based regimens. In this report, we analyzed outcomes in 7080 patients (46.4%) who, at the end of the initial drug adjustment period (6 months), remained on monotherapy. Baseline characteristics were similar in the valsartan (N=3263) and amlodipine (N=3817) groups. Time on monotherapy was 3.2 years (78% of treatment exposure time). The average in-trial blood pressure was similar in both groups. Event rates in the monotherapy group were 16% to 39% lower than in the main VALUE trial. In the first analysis, we censored patients when they discontinued monotherapy ("censored"); in the second, we counted events regardless of subsequent therapy (intention-to-treat principle). We also assessed the impact of duration of monotherapy on outcomes. No difference was found in primary composite cardiac end points, strokes, myocardial infarctions, and all-cause deaths with both analyses. Heart failure in the valsartan group was lower both in the censored and intention-to-treat analyses (hazard ratios: 0.63, P=0.004 and 0.78, P=0.045, respectively). Longer duration of monotherapy amplified between-group differences in heart failure. New-onset diabetes was lower in the valsartan group with both analyses (odds ratios: 0.78, P=0.012 and 0.82, P=0.034). Thus, despite lower absolute event rates in monotherapy patients, the relative risks of heart failure and new-onset diabetes favored valsartan. Moreover, these findings support the feasibility of comparative prospective trials in lower-risk hypertensive patients.

Olmesartan medoxomil: current status of its use in monotherapy.

Olmesartan medoxomil is an angiotensin II receptor antagonist. In pooled analyses of seven randomized, double-blind trials, 8 weeks' treatment with olmesartan medoxomil was significantly more effective than placebo in terms of the response rate, proportion of patients achieving target blood pressure (BP) and mean change from baseline in diastolic (DBP) and systolic blood pressure (SBP). Olmesartan medoxomil had a fast onset of action, with significant between-group differences evident from 2 weeks onwards. The drug was well tolerated with a similar adverse event profile to placebo. In patients with type 2 diabetes, olmesartan medoxomil reduced renal vascular resistance, increased renal perfusion, and reduced oxidative stress. In several large, randomized, double-blind trials, olmesartan medoxomil 20 mg has been shown to be significantly more effective, in terms of primary endpoints, than recommended doses of losartan, valsartan, irbesartan, or candesartan cilexetil, and to provide better 24 h BP protection. Olmesartan medoxomil was at least as effective as amlodipine, felodipine and atenolol, and significantly more effective than captopril. The efficacy of olmesartan medoxomil in reducing cardiovascular risk beyond BP reduction is currently being investigated in trials involving patients at high risk due to atherosclerosis or type 2 diabetes.

Sustained 24-hour blockade of the renin-angiotensin system: a high dose of a long-acting blocker is as effective as a lower dose combined with an angiotensin-converting enzyme inhibitor.

Whether a higher dose of a long-acting angiotensin II receptor blocker (ARB) can provide as much blockade of the renin-angiotensin system over a 24-hour period as the combination of an angiotensin-converting enzyme inhibitor and a lower dose of ARB has not been formally demonstrated so far. In this randomized double-blind study we investigated renin-angiotensin system blockade obtained with 3 doses of olmesartan medoxomil (20, 40, and 80 mg every day) in 30 normal subjects and compared it with that obtained with lisinopril alone (20 mg every day) or combined with olmesartan medoxomil (20 or 40 mg). Each subject received 2 dose regimens for 1 week according to a crossover design with a 1-week washout period between doses. The primary endpoint was the degree of blockade of the systolic blood pressure response to angiotensin I 24 hours after the last dose after 1 week of administration. At trough, the systolic blood pressure response to exogenous angiotensin I was 58% +/- 19% with 20 mg lisinopril (mean +/- SD), 58% +/- 11% with 20 mg olmesartan medoxomil, 62% +/- 16% with 40 mg olmesartan medoxomil, and 76% +/- 12% with the highest dose of olmesartan medoxomil (80 mg) (P = .016 versus 20 mg lisinopril and P = .0015 versus 20 mg olmesartan medoxomil). With the combinations, blockade was 80% +/- 22% with 20 mg lisinopril plus 20 mg olmesartan medoxomil and 83% +/- 9% with 20 mg lisinopril plus 40 mg olmesartan medoxomil (P = .3 versus 80 mg olmesartan medoxomil alone). These data demonstrate that a higher dose of the long-acting ARB olmesartan medoxomil can produce an almost complete 24-hour blockade of the blood pressure response to exogenous angiotensin in normal subjects. Hence, a higher dose of a long-acting ARB is as effective as a lower dose of the same compound combined with an angiotensin-converting enzyme inhibitor in terms of blockade of the vascular effects of angiotensin.

Neuropeptide Y expression, localization and cellular transducing effects in HUVEC.

BACKGROUND INFORMATION: NPY (neuropeptide Y) may have an effect on the properties of vascular endothelial cells such as pro-angiogenic effects and potentiation of noradrenaline-induced vasoconstriction. In HUVEC (human umbilical-vein endothelial cells), immunoreactive neuropeptide Y has been detected, but NPY synthesis, storage and secretion have not been studied. The aim of the present study was to establish NPY expression, storage and cellular transducing effects in HUVEC. RESULTS: HUVEC contain 0.19 fmol of NPY/microg of protein and 0.46 fmol of pro-NPY/microg of protein, as measured by ELISA. RT (reverse transcriptase)-PCR confirmed the expression of NPY in HUVEC. Immunofluorescence revealed the presence of NPY in small punctate structures, with a fluorescence pattern different from that observed for von Willebrand factor, indicating distinct storage compartments. Double labelling for NPY and Rab3A demonstrated similar granular patterns, with at least partial co-localization. Electron microscopy showed NPY immunoreactivity in vesicle-like cytoplasmic structures, of a fine fibrillar texture, as well as in mitochondria and in the nucleus. A similar general distribution pattern was also obtained for Rab3A. Y1 and Y2 receptors were expressed in HUVEC as assessed by RT-PCR, and they were functional since NPY induced a 42 nM intracellular calcium increase within 100 s, representing 22% of the histamine-induced response. In contrast with histamine, NPY did not induce acute von Willebrand factor secretion. CONCLUSIONS: HUVEC produce, store and respond to NPY, suggesting an autocrine regulatory role for NPY in the endothelium.

Renal endothelin receptor type B upregulation in rats with low or high renin hypertension.

OBJECTIVES: To evaluate the role of endothelin-1 (ET-1) in hypertension, we investigated density and distribution of ETA and ETB receptors in hearts and kidneys of deoxycorticosterone acetate (DOCA)-salt and 1 kidney -- 1 clip (1K1C) hypertensive rats. METHODS: Five groups of uninephrectomized Wistar rats were put on a low salt diet. Three groups of rats drank tap water and two groups received saline. One group of each regimen received DOCA subcutaneously and two corresponding groups without DOCA served as controls. The fifth group of rats had the renal artery clipped to induce 1K1C hypertension. At 6 weeks, mean arterial pressure (MAP) was recorded and membrane binding assays using 125I-ET-1 were carried out. RESULTS: MAP was increased from control 122 +/- 3 to 155 +/- 6 and 218 +/- 11 mmHg in DOCA-salt and 1K1C rats, respectively, and cardiac weight index was increased. ETA receptors were predominantly expressed in the heart, whereas ETB receptors were predominant in the kidney. In the kidneys, the density of the ETB receptor subtype was upregulated in DOCA-salt and 1K1C rats from 160 +/- 8 to 217 +/- 12 and 190 +/- 2 fmol/mg (P < 0.05), respectively, and ETA tended to be downregulated (P = 0.057). Plasma renin activity was decreased in DOCA-salt rats from 17 +/- 3 to 0.17 +/- 0.01 ng/ml per h and increased in 1K1C rats on low salt diet to 30 +/- 5 ng/ml per h. CONCLUSIONS: Since ETB is the predominant endothelin receptor in the kidneys, upregulation of the ETB receptor mediating vasodilation and downregulation of the ETA receptor mediating vasoconstriction would be compatible with a mainly renal counter-regulatory effect of endothelin-1 to hypertension. Both low and high renin models of hypertension may be affected.

Endogenous angiotensin II induces atherosclerotic plaque vulnerability and elicits a Th1 response in ApoE-/- mice.

Rupture of vulnerable plaques is the main cause of acute cardiovascular events. However, mechanisms responsible for transforming a stable into a vulnerable plaque remain elusive. Angiotensin II, a key regulator of blood pressure homeostasis, has a potential role in atherosclerosis. To study the contribution of angiotensin II in plaque vulnerability, we generated hypertensive hypercholesterolemic ApoE-/- mice with either normal or endogenously increased angiotensin II production (renovascular hypertension models). Hypertensive high angiotensin II ApoE-/- mice developed unstable plaques, whereas in hypertensive normal angiotensin II ApoE-/- mice plaques showed a stable phenotype. Vulnerable plaques from high angiotensin II ApoE-/- mice had thinner fibrous cap (P<0.01), larger lipid core (P<0.01), and increased macrophage content (P<0.01) than even more hypertensive but normal angiotensin II ApoE-/- mice. Moreover, in mice with high angiotensin II, a skewed T helper type 1-like phenotype was observed. Splenocytes from high angiotensin II ApoE-/- mice produced significantly higher amounts of interferon (IFN)-gamma than those from ApoE-/- mice with normal angiotensin II; secretion of IL4 and IL10 was not different. In addition, we provide evidence for a direct stimulating effect of angiotensin II on lymphocyte IFN-gamma production. These findings suggest a new mechanism in plaque vulnerability demonstrating that angiotensin II, within the context of hypertension and hypercholesterolemia, independently from its hemodynamic effect behaves as a local modulator promoting the induction of vulnerable plaques probably via a T helper switch.

Clinical efficacy and tolerability of olmesartan.

BACKGROUND: Olmesartan medoxomil is an angiotensin II receptor antagonist that selectively and competitively inhibits the angiotensin II type 1 receptor. OBJECTIVE: This article reviews the results of some key studies that assessed the efficacy and tolerability of olmesartan in patients with hypertension. METHODS: Olmesartan has been investigated in several clinical studies. This article reports on data from 1 such study with a prospective, randomized, double-blind, placebo-controlled, parallel-group, dose-finding design in patients with mild to moderate hypertension (baseline mean sitting diastolic blood pressure, 100-114 mm Hg). The results from a meta-analysis of 7 randomized, double-blind, placebo-controlled studies are also presented. RESULTS: In the dose-finding study, 792 patients were randomized to olmesartan (2.5-80 mg) or placebo once daily, and changes were recorded in trough mean sitting diastolic and systolic blood pressures from baseline to the end of a 12-week treatment period. For the meta-analysis, 3055 patients were randomized to treatment; 2511 received olmesartan. In the dose-finding study as well as in the meta-analysis, olmesartan (2.5-80 mg once daily) produced a dose-dependent decrease in diastolic and systolic blood pressures, and at a dose of 10 to 80 mg showed significant superiority in reducing diastolic blood pressure over placebo (P < 0.05). The 20-mg dose was considered optimal, with a responder rate of 70%. Furthermore, in a 2-year study with 462 patients, olmesartan had a good safety profile and was well tolerated. The results of the clinical studies in >3000 patients receiving olmesartan showed that the frequency and profile of adverse events with olmesartan were generally similar to those with placebo; the frequency of adverse events was not dose related. Olmesartan, with or without hydrochlorothiazide, was well tolerated over 2 years of treatment.

Outcomes in hypertensive patients at high cardiovascular risk treated with regimens based on valsartan or amlodipine: the VALUE randomised trial.

BACKGROUND: The Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial was designed to test the hypothesis that for the same blood-pressure control, valsartan would reduce cardiac morbidity and mortality more than amlodipine in hypertensive patients at high cardiovascular risk. METHODS: 15?245 patients, aged 50 years or older with treated or untreated hypertension and high risk of cardiac events participated in a randomised, double-blind, parallel-group comparison of therapy based on valsartan or amlodipine. Duration of treatment was event-driven and the trial lasted until at least 1450 patients had reached a primary endpoint, defined as a composite of cardiac mortality and morbidity. Patients from 31 countries were followed up for a mean of 4.2 years. FINDINGS: Blood pressure was reduced by both treatments, but the effects of the amlodipine-based regimen were more pronounced, especially in the early period (blood pressure 4.0/2.1 mm Hg lower in amlodipine than valsartan group after 1 month; 1.5/1.3 mm Hg after 1 year; p<0.001 between groups). The primary composite endpoint occurred in 810 patients in the valsartan group (10.6%, 25.5 per 1000 patient-years) and 789 in the amlodipine group (10.4%, 24.7 per 1000 patient-years; hazard ratio 1.04, 95% CI 0.94-1.15, p=0.49). INTERPRETATION: The main outcome of cardiac disease did not differ between the treatment groups. Unequal reductions in blood pressure might account for differences between the groups in cause-specific outcomes. The findings emphasise the importance of prompt blood-pressure control in hypertensive patients at high cardiovascular risk.

Blood pressure dependent and independent effects of antihypertensive treatment on clinical events in the VALUE Trial.

The Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial was designed to test whether, for the same achieved blood pressures, regimens based on valsartan or amlodipine would have differing effects on cardiovascular endpoints in high risk hypertension. But inequalities in blood pressure, favouring amlodipine, throughout the multiyear trial precluded comparison of outcomes. A technique of serial median matching, applied at 6 months when treatment adjustments intended to achieve control of blood pressure were complete, created 5006 valsartan-amlodipine patient pairs matched exactly for systolic blood pressure, age, sex, and the presence or absence of previous coronary disease, stroke, or diabetes. Subsequent combined cardiac events, myocardial infarction, stroke, and mortality were almost identical in the two cohorts, but admission to hospital for heart failure was significantly lower with valsartan. Reaching blood pressure control (systolic <140 mm Hg) by 6 months, independent of drug type, was associated with significant benefits for subsequent major outcomes; the blood pressure response after just 1 month of treatment predicted events and survival.

Angiotensin II receptor blockade prevents acute renal sodium retention induced by low levels of orthostatic stress.

BACKGROUND: Depending on its magnitude, lower body negative pressure (LBNP) has been shown to induce a progressive activation of neurohormonal, renal tubular, and renal hemodynamic responses, thereby mimicking the renal responses observed in clinical conditions characterized by a low effective arterial volume such as congestive heart failure. Our objective was to evaluate the impact of angiotensin II receptor blockade with candesartan on the renal hemodynamic and urinary excretory responses to a progressive orthostatic stress in normal subjects. METHODS: Twenty healthy men were submitted to three levels of LBNP (0, -10, and -20 mbar or 0, -7.5, and -15 mm Hg) for 1 hour according to a crossover design with a minimum of 2 days between each level of LBNP. Ten subjects were randomly allocated to receive a placebo and ten others were treated with candesartan 16 mg orally for 10 days before and during the three levels of LBNP. Systemic and renal hemodynamics, renal sodium excretions, and the hormonal response were measured hourly before, during, and for 2 hours after LBNP. RESULTS: During placebo, LBNP induced no change in systemic and renal hemodynamics, but sodium excretion decreased dose dependently with higher levels of LBNP. At -20 mbar, cumulative 3-hour sodium balance was negative at -2.3 +/- 2.3 mmol (mean +/- SEM). With candesartan, mean blood pressure decreased (76 +/- 1 mm Hg vs. 83 +/- 3 mm Hg, candesartan vs. placebo, P < 0.05) and renal plasma flow increased (858 +/- 52 mL/min vs. 639 +/- 36 mL/min, candesartan vs. placebo, P < 0.05). Glomerular filtration rate (GFR) was not significantly higher with candesartan (127 +/- 7 mL/min in placebo vs. 144 +/- 12 mL/min in candesartan). No significant decrease in sodium and water excretion was found during LBNP in candesartan-treated subjects. At -20 mbar, the 3-hour cumulative sodium excretion was + 4.6 +/- 1.4 mmol in the candesartan group (P= 0.02 vs. placebo). CONCLUSION: Selective blockade of angiotensin II type 1 (AT1) receptors with candesartan increases renal blood flow and prevents the antinatriuresis during sustained lower body negative pressure despite a modest decrease in blood pressure. These results thus provide interesting insights into potential benefits of AT1 receptor blockade in sodium-retaining states such as congestive heart failure.