The renin-angiotensin-aldosterone system has been implicated in the control of structural changes of the heart and the vasculature, beyond the effects on blood pressure. This projects examines the importance of the renin-angiotensin-aldosterone system and the sympathetic nervous system in the control of cardiac and vascular structure and function in subjects with hypertension.Patients with hypertension and left ventricular hypertrophy were randomized to an angiotensin receptor blocker or a beta adrenergic receptor blocker for 48 weeks. Repeat investigations of blood pressure, structure and function of the heart and the vascular tree, and neurohormones were performed. Two control groups, consisting of normotensive subjects and of hypertensive subjects with no cardiac hypertrophy were also examined for comparison.
We included 115 patients with hypertension and cardiac hypertrophy, established by echocardiography. Extensive echocardiographic examinations, ultrasonography of the carotid arteries, 24h Holter registrations, 24h ambulatory blood pressure monitoring monitoring, neurohormones and blood samples for inflammation and hemostasis markers and endothelial function were done at weeks 0, 12, 24, and 48. Matched control groups (1:3, i.e. 38 normotensive subjects and 38 hypertensive subjects with no signs of hypertensive heart disease were examined at one occasion. All patients obtained irbesartan or atenolol for 12 weeks; a diuretic and a calcium antagonist was added when needed thereafter in order to obtained a blood pressure below 140/90 mm Hg. All analyses were performed central in a core laboratory.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
115
Titrated to 300 mg od, 48 weeks.
Titrated to 100 mg od, 48 weeks.
Karolinska Institutet, Daprtment of Clinical Sciences, Danderyd Hospital, Cardiovascular Research Laboratory
Stockholm, Sweden
Changes in Left Ventricular Mass Index
Repeated measures multivariate analysis of variance (MANOVA) at time points 0, 12, 24, and 48 weeks. Data are presented as left ventricular mass in gram (g) indexed for body mass index (in m\^2).
Time frame: Baseline and 48 weeks
Number of Participants With Serious Adverse Events
Safety was assessed by non-directed questions, and all observed and volunteered adverse events were recorded at each study visit. Serious adverse events were defined by, and reported according to the regulations of good clinical practice (GCP). none were considered related to the study medication.
Time frame: Treatment period was baseline to 48 weeks
Left Ventricular Diastolic Function Assessed by the E/A Ratio
Changes in left ventricular diastolic function from baseline to week 48 will be evaluated as the difference in E/A ratio. Conventional pulsed wave Doppler echocardiography was used for recordings of mitral inflow in. The peak of early (E) and late (A) mitral flow velocities were measured, and the E/A-ratio was calculated. Repeated measures MANOVA at time points 0, 12, 24, and 48 weeks. Some echocardiographic recordings at some time point may be of insufficient quality or missing, and the number of observations may not always correspond to the total number of participants at all time points.
Time frame: Baseline to 48 weeks
Blood Pressure
Difference in Diastolic Blood Pressure. Repeated measures multivariable analysis of variance (MANOVA) at time points 0, 12, 24, and 48 weeks
Time frame: Baseline to 48 weeks
Changes of Venous Plasma Angiotensin II as a Marker of the Renin-Angiotensin-Aldosterone System
Venous plasma concentrations of angiotensin II were measured in order to study the possible associations between the activity of the renin-angiotensin-aldosteone system and changes in left ventricular mass. Further analyses of other components of the renin-angiotensin-aldosterone system and of other hormonal system (e.g. the sympathetic nervous system) have also been performed and published. Repeated measures MANOVA at time points 0, 12, 24, and 48 weeks. Data were log-transformed to avoid skewness before statistical evaluation. However, tabular data are given as mean values with 95% confidence to improve readability.
Time frame: Baseline to 48 weeks
Effects on Carotid Artery Wall Thickness
Changes in common carotid artery intima-media thickness, assessed by ultrasonography.
Time frame: Baseline to 48 weeks
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