Left ventricular hypertrophy increases the risk for cardiovascular target organ damage, myocardial infarction, and stroke. The authors assessed the patterns of ventricular adaptation in 107 essential hypertensives whose treatment had been withdrawn and its modification after 1 year of hypertension treatment. Blood pressure decreased from 158+17/96+12 mm Hg to 137+15/83+10 mm Hg (mean + SD; p<0.001); 45% of the patients (49 of 107) had their blood pressure controlled below 140 mm Hg and 90 mm Hg. Although a significant decrease of left ventricular mass index was found in the study, the percentage of patients with normal left ventricular geometry at the completion of the study increased by only 9% (27% to 36%, p>0.05). Left ventricular mass geometry improved in 31% of the patients, remained unaffected in 51%, and worsened in 18%. The data suggest that even while suboptimal antihypertensive treatment reduces left ventricular mass index, either left ventricular hypertrophy or concentric remodeling remains present in a significant number of patients at the end of a 1-year treatment period. The authors conclude that these patients should be considered as a subgroup at high risk and should be treated more aggressively.