Objectives: To compare the effect of the angiotensin converting enzyme (ACE) inhibitor ramipril with that of the beta-blocker atenolol on reversal of left ventricular hypertrophy, on blood pressure and on other echocardiographic parameters.
Design: The study was conducted in accord with the PROBE (prospective randomized open blinded endpoint) design. Randomized treatment either with ramipril or with atenolol was continued for 6 months, and echocardiograms were recorded before and after 3 and 6 months of treatment. The echo tracings were blindly evaluated in a single reading centre.
Methods: M-mode, two-dimensional guided echocardiography was used to measure left ventricular wall thicknesses and dimensions, from which left ventricular mass was calculated, according to the Penn convention.
Results: Of 193 patients at 16 centres, 111 had echocardiograms that could be quantitatively evaluated. The primary analysis of the study was performed using data from those patients. In addition, echocardiograms of 88 patients were analysed on an 'according to protocol' basis (patients with preset values of left ventricular mass). Systolic and diastolic blood pressures were significantly reduced both by ramipril and by atenolol without any significant difference between the two drug treatments. The heart rate was significantly reduced by atenolol only. Both the 'primary' and the 'according to protocol' analyses showed that the left ventricular mass was significantly reduced by ramipril only. Comparison between treatments according to a multivariate analysis demonstrated a significantly greater reduction in left ventricular mass during ramipril than during atenolol treatment.
Conclusions: The present study is the first of suitably large size in which a direct comparison of the effects of an ACE inhibitor and a beta-blocker on echocardiographic left ventricular mass has been performed. It has demonstrated that ramipril is more effective than atenolol in reversing left ventricular hypertrophy in essential hypertensive patients.