ObjectiveTo compare the efficacy of indapamide sustained release (SR) 1.5 mg and enalapril 20 mg at reducing left ventricular mass index (LVMI) in hypertensive patients with left ventricular hypertrophy (LVH).DesignThe LIVE study (left ventricular hypertrophy regression, indapamide versus enalapril) was a 1 year, prospective, randomized, double-blind study. For the first time, a committee validated LVH before inclusion, provided on-going quality control during the study, and performed an end-study reading of all echocardiograms blinded to sequence.SettingEuropean hospitals, general practitioners and cardiologists.PatientsHypertensive patients aged ≥ 20 years with LVH (LVMI in men > 120 g/m2; LVMI in women > 100 g/m2). Data were obtained from 411 of 505 randomized patients.InterventionsIndapamide SR 1.5 mg, or enalapril 20 mg, daily for 48 weeks.Main outcome measuresLVMI variation in the per-protocol population.ResultsIndapamide SR 1.5 mg significantly reduced LVMI (−8.4 ± 30.5 g/m2from baseline;P< 0.001), but enalapril 20 mg did not (−1.9 ± 28.3 g/m2). Indapamide SR 1.5 mg reduced LVMI significantly more than enalapril 20 mg: −6.5 g/m2,P= 0.013 (−4.3 g/m2when adjusted for baseline values;P= 0.049). Both drugs equally and significantly reduced blood pressures (P< 0.001), without correlation with LVMI changes. Indapamide SR progressively reduced wall thicknesses throughout the 1-year treatment period. In contrast, the effect of enalapril observed at 6 months was not maintained at 12 months.ConclusionsIndapamide SR 1.5 mg was significantly more effective than enalapril 20 mg at reducing LVMI in hypertensive patients with LVH.