Reproducibility of 3-dimensional ultrasound readings of volume of carotid atherosclerotic plaque.

BACKGROUND: Non-invasive 3-dimensional (3D) ultrasound (US) has emerged as the predominant approach for evaluating the progression of carotid atherosclerosis and its response to treatment. The aim of this study was to investigate the quality of a central reading procedure concerning plaque volume (PV), measured by 3D US in a multinational US trial. METHODS: Two data sets of 45 and 60 3D US patient images of plaques (mean PV, 71.8 and 39.8 mul, respectively) were used. PV was assessed by means of manual planimetry. The intraclass correlation coefficient (ICC) was applied to determine reader variabilities. The repeatability coefficient (RC) and the coefficient of variation (CV) were used to investigate the effect of number of slices (S) in manual planimetry and plaque size on measurement variability. RESULTS: Intra-reader variability was small as reflected by ICCs of 0.985, 0.967 and 0.969 for 3 appointed readers. The ICC value generated between the 3 readers was 0.964, indicating that inter-reader variability was small, too. Subgroup analyses showed that both intra- and inter-reader variabilities were lower for larger than for smaller plaques. Mean CVs were similar for the 5S- and 10S-methods with a RC of 4.7 microl. The RC between both methods as well as the CVs were comparatively lower for larger plaques. CONCLUSION: By implementing standardised central 3D US reading protocols and strict quality control procedures highly reliable ultrasonic re-readings of plaque images can be achieved in large multicentre trials.

Effect of angiotensin receptor blockade on central haemodynamics in essential hypertension: results of a randomised trial.

OBJECTIVE: Angiotensin-converting enzyme (ACE) inhibitors have been shown to lower central augmentation index (cAI), an index of arterial wave reflection, more than beta-blockers. We tested whether this is also true for long-term treatment with an angiotensin receptor blocker (ARB). METHODS: One-hundred and fifty-six subjects with essential hypertension were randomised to treatment with either irbesartan or atenolol. cAI and central blood pressure (BP) were determined by pulse wave analysis from the radial and the carotid artery after six and after 18 months treatment. RESULTS: Peripheral and central systolic and diastolic BP were reduced to a similar extent in the two groups. cAI was reduced with irbesartan, but increased with atenolol (derived from the carotid artery: -6+/-10 vs. -4+/-12% after six months, p<0.001; -4+/-12 vs. +1+/-11% after 18 months; p=0.011). Furthermore, central to peripheral pulse pressure (PP) amplification was unaffected by treatment with irbesartan, but decreased with atenolol. CONCLUSIONS: Although treatment with irbesartan and atenolol similarly decreased peripheral and central BP, only treatment with irbesartan had beneficial effects on arterial wave reflection and preserved PP amplification. These haemodynamic effects may at least partly explain the reported differential effects of ARB versus beta-blocker treatment on cardiovascular mortality in patients with essential hypertension.

Carotid intima-media thickness and plaque volume changes following 2-year angiotensin II-receptor blockade. The Multicentre Olmesartan atherosclerosis Regression Evaluation (MORE) study.

OBJECTIVE: The Multicentre Olmesartan atherosclerosis Regression Evaluation (MORE) study was a double-blind trial in patients with hypertension at increased cardiovascular risk with carotid wall thickening and a defined atherosclerotic plaque that used non-invasive 2- and 3-dimensionaL (D) ultrasound (US), to compare the effects of a 2-year treatment based on either olmesartan medoxomil or atenolol on common carotid (CC) intima-media thickness (IMT) and plaque volume (PV). METHODS: A total of 165 patients (with systolic/diastolic blood pressure 140-180/ 90-105 mmHg) were randomized to receive either olmesartan (20-40 mg/day) or atenolol (50-100 mg/day). US was performed at baseline and 28, 52 and 104 weeks. The primary efficacy outcome was the change from baseline ( Delta) in CC-IMT assessed by 2D US. Secondary outcomes included Delta PV assessed by 3D US and blood pressure (BP). RESULTS: Olmesartan and atenolo produced comparable significant reductions in CC-IMT; mean Delta IMT (SEM) was -0.090 (0.015) mm for oLmesartan and -0.082 (0.014) mm for atenolol. Mean Delta PV was -4.4 (2.3) microl and 0.1 (1.5) microl in the olmesartan and atenolol treated subjects, respectively, without significant between-treatment differences. In the subgroup of patients with baseLine PV > or = median (33.7 microl), significant between-treatment differences existed in Delta PV (p = 0.023), because PV regressed significantly with olmesartan (Delta PV: -11.5 (4.4) microl) but not with atenolol ( Delta PV: 0.6 (2.5) microl). In these patients BP reductions were comparabLe. CONCLUSIONS: Carotid IMT and BP decreased similarly with olmesartan and atenolol, but only olmesartan reduced the volume of larger atherosclerotic plaques.

Olmesartan compared with other angiotensin II receptor antagonists: head-to-head trials.

BACKGROUND: Drugs that block the renin-angiotensin system represent one of the most significant therapeutic interventions available for the treatment of hypertension. The angiotensin II receptor antagonists (AIIRAs), also known as sartans, are one such class of drugs that block the effects of angiotensin II by antagonizing the angiotensin II type 1 receptor. Olmesartan is the newest member of this class. OBJECTIVE: The present article reviews 3 head-to-head trials directly comparing the antihypertensive efficacy of olmesartan with that of 4 other AIIRAs, at recommended maintenance doses, already in clinical use for the treatment of hypertension. RESULTS: In the first study, olmesartan 10 mg/d was compared with losartan 50 mg/d in 316 patients with mild to moderate hypertension (mean baseline diastolic blood pressure [DBP], 95-114 mm Hg). Dosage was doubled at week 4 and hydrochlorothiazide was added at week 12 if blood pressure response was inadequate. Olmesartan was significantly more effective than losartan with respect to the reduction in blood pressure at weeks 2, 4, and 12, and to the responder rate at weeks 2 and 4 (with the starting dose of the respective drug). In a second study, olmesartan 20 mg/d was shown to be significantly more effective than losartan 50 mg/d, valsartan 80 mg/d, and irbesartan 150 mg/d in 588 patients with mild to moderate hypertension (mean sitting baseline DBP, 100-115 mm Hg) (P < or = 0.05). At week 2, the reduction in blood pressure observed with olmesartan was significantly greater than that of the comparator treatments (P < or = 0.05). The superiority of olmesartan was maintained at week 8. The third study involved 643 evaluable patients with moderate to severe hypertension (mean DBP, 100-120 mm Hg; mean systolic blood pressure, >150 mm Hg). Olmesartan 20 mg/d was more effective than candesartan 8 mg/d in lowering 24-hour blood pressure at week 8 (P < or = 0.05). Most of this treatment effect was evident after only 1 or 2 weeks, with greater reductions in blood pressure compared with candesartan. CONCLUSIONS: These data indicate that, at the doses studied, olmesartan is more effective than other AIIRAs tested at their recommended doses, in terms of reduction of cuff or 24-hour ambulatory blood pressure, in patients with essential hypertension. These differences in blood pressure reduction between these agents may be clinically relevant and have important long-term implications. Additional studies will further define the role of olmesartan in the management of cardiovascular diseases, such as atherosclerosis.

Effect of irbesartan versus atenolol on left ventricular mass and voltage: results of the CardioVascular Irbesartan Project.

Regression of hypertensive left ventricular hypertrophy (LVH) is associated with improved prognosis. The aim of this trial was to compare the effects of irbesartan versus atenolol on LVH in subjects with essential hypertension. Because electrocardiographic and echocardiographic parameters of LVH carry disparate prognostic information, both methods were applied in this trial. In the randomized, double-blind, multicenter trial CardioVascular Irbesartan Project, 240 patients with essential hypertension were treated with irbesartan or atenolol for 18 months. Voltage criteria used for LVH were Sokolow index, Cornell index, Cornell voltage x QRS duration product and Lewis index. In parallel, left ventricular mass (LVM) was determined by 2-dimensional guided M-mode echocardiography. After 6 and 18 months, reductions of LVM and voltage criteria for LVH were only found in subjects treated with irbesartan. However, a reduction of LVM was only detectable in subjects within the highest quartile of baseline LVM but not overall. In contrast, reductions of voltage criteria for LVH were detectable after 6 and 18 months even within commonly used normal limits. In conclusion, treatment of hypertension with irbesartan resulted in a significant reduction in the voltage criteria for LVH, although an effect on LVM was only seen in subjects with high baseline LVM. In contrast, atenolol did not lead to reductions in electrocardiographic or echocardiographic parameters of LVH. Because voltage criteria for LVH have been shown to predict cardiovascular outcome independently from LVM, we suggest that both methods should be used to accurately assess the benefits of antihypertensive treatment.

Antihypertensive efficacy of olmesartan medoxomil and candesartan cilexetil assessed by 24-hour ambulatory blood pressure monitoring in patients with essential hypertension.

OBJECTIVE: To compare the antihypertensive efficacy of olmesartan medoxomil with that of candesartan cilexetil after 1, 2 and 8 weeks of treatment. DESIGN AND SETTING: Randomised, double-blind, parallel-group study conducted at 44 centres in Germany, Poland and the Czech Republic. PATIENTS: 643 patients (aged 19-86 years) with mainly mild-to-moderate essential hypertension received active double-blind treatment. INTERVENTIONS: Following a 2-week placebo run-in, eligible patients were randomly assigned to receive olmesartan medoxomil 20mg (n = 319) or candesartan cilexetil 8mg (n = 324) once daily for 8 weeks. MAIN OUTCOME MEASURES: Changes from baseline in daytime, 24-hour and night-time diastolic (DBP) and systolic (SBP) blood pressures assessed by ambulatory blood pressure monitoring (ABPM), and changes from baseline in sitting cuff DBP and SBP. RESULTS: Mean decreases from baseline in daytime DBP by ABPM at weeks 1, 2 and 8 were 6.7, 8.4 and 9.3mm Hg, respectively, in the olmesartan medoxomil group compared with 5.3, 6.0 and 7.8mm Hg, respectively, in the candesartan cilexetil group. The between-group differences were significantly in favour of olmesartan medoxomil at all three timepoints (p

Comparison of the effects of losartan and atenolol on common carotid artery intima-media thickness in patients with hypertension: results of a 2-year, double-blind, randomized, controlled study.

BACKGROUND: Hypertension induces progressive pathologic changes in the arterial wall. Experimental findings suggest that these changes, which include intima-media thickening, may be mediated, at least in part, by angiotensin II (AII). OBJECTIVE: The Losartan Vascular Regression Study (LAARS) was a double-blind, parallel-group, randomized, controlled, multicenter study designed to compare the effects of the AII antagonist losartan and the beta-blocker atenolol on ultrasonographically determined intimamedia thickness (IMT) of the common carotid artery (CCA) in patients with mild to moderate essential hypertension. METHODS: The primary end point of the study was the yearly rate of change (YRC) from baseline of the mean IMT of the CCA (CCA-IMT(mean)) averaged over 2 years of treatment. Secondary end points included IMT of the common femoral artery and sitting systolic and diastolic blood pressures (SiSBP/SiDBP). Safety assessments of losartan and atenolol were made by statistical and clinical review of the incidence of adverse experiences as well as review of vital signs and laboratory values. A total of 414 patients with essential hypertension were screened for study inclusion at 36 study centers in Germany and Brazil. Patients received losartan (50 mg once daily) or atenolol (50 mg once daily) for 24 months. Target blood pressure (SiSBP/SiDBP <140/<90 mm Hg) was achieved by adding hydrochlorothiazide 12.5 mg once daily, doubling the dose of study drug, or adding an open-label calcium channel blocker sequentially, as needed. RESULTS: Of the original 414 patients screened, 280 hypertension patients (SiDBP 95-115 mm Hg), aged 35 to 65 years, with an IMT of 0.8 to 1.5 mm of the right or left CCA, were randomized to treatment with either losartan (n = 142) or atenolol (n = 138). Both losartan and atenolol therapy produced comparable reductions in CCA-IMTmean over 24 months compared with baseline; the average YRC was -0.038 +/- 0.004 mm/y (P < or = 0.001) for losartan and -0.037 +/- 0.004 mm/y (P < or = 0.001) for atenolol. There were no significant differences between groups. Losartan showed a greater reduction of femoral artery IMT than did atenolol; the average YRC was -0.024 mm/y (P < or = 0.05) for losartan and -0.017 mm/y for atenolol (P = NS), with no significant difference between groups. Both agents produced similar significant reductions in SiSBP and SiDBP and were generally well tolerated. Approximately 7% of losartan patients had drug-related clinical adverse events, compared with 12% of atenolol patients. CONCLUSIONS: The findings of LAARS, the first large study with an AII antagonist that examined IMT, suggest that AII antagonism reverses the early stages of vascular hypertrophy in patients with hypertension. Further studies are needed to delineate the relative importance of AII antagonism versus blood pressure reduction per se in mediating the beneficial vascular effects of losartan.