Comparison of enalapril versus nifedipine to decrease left ventricular hypertrophy in systemic hypertension (the PRESERVE trial).
The PRESERVE (Prospective Randomized Enalapril Study Evaluating Regression of Ventricular Enlargement) study is designed to provide a definitive test of the ability of enalapril to achieve greater left ventricular (LV) mass reduction than nifedipine GITs (gastrointestinal treatment system) by a degree that would be prognostically meaningful on a population basis (10 g/m2). To achieve this goal, an ethnically diverse population of 480 men and women with essential hypertension and increased LV mass of screening echocardiography will be enrolled at clinical centers on 4 continents and studied by echocardiography at baseline and after 6 and 12 months' randomized therapy. Blinded readings of echocardiograms at a central laboratory will provide systematic information about treatment effects on LV structure, wall motion, and Doppler blood flow. The study power is at least 90% to test the primary hypotheses that enalapril will induce greater normalization of LV mass and diastolic filling than nifedipine. After the 1-year echocardiographic trial, the study population will be followed 3 more years to test the hypothesis that a reduction in LV mass, independent of blood pressure lowering, is associated with a reduction in the risk of morbid and fatal cardiovascular events.