Abstract. It is not known whether prevention of anemia among patients with chronic kidney disease would affect the development or progression of left ventricular (LV) hypertrophy. A randomized controlled trial was performed with 155 patients with chronic kidney disease (creatinine clearance, 15 to 50 ml/min), with entry hemoglobin concentrations ([Hb]) of 110 to 120 g/L (female patients) or 110 to 130 g/L (male patients). Patients were monitored for 2 yr or until they required dialysis; the patients were randomized to receive epoetin ␣ as necessary to maintain [Hb] between 120 and 130 g/L (group A) or between 90 and 100 g/L (group B). [Hb] increased for group A (from 112 Ϯ 9 to 121 Ϯ 14 g/L, mean Ϯ SD) and decreased for group B (from 112 Ϯ 8 to 108 Ϯ 13 g/L) (P Ͻ 0.001, group A versus group B). On an intent-to-treat analysis, the changes in LV mass index for the groups during the 2-yr period were not significantly different (2.5 Ϯ 20 g/m 2 for group A versus 4.5 Ϯ 20 g/m 2 for group B, P ϭ NS). There was no significant difference between the groups in 2-yr mean unadjusted systolic BP (141 Ϯ 14 versus 138 Ϯ 13 mmHg) or diastolic BP (80 Ϯ 6 versus 79 Ϯ 7 mmHg). The decline in renal function in 2 yr, as assessed with nuclear estimations of GFR, also did not differ significantly between the groups (8 Ϯ 9 versus 6 Ϯ 8 ml/min per 1.73 m 2 ). In conclusion, maintenance of [Hb] above 120 g/L, compared with 90 to 100 g/L, had similar effects on the LV mass index and did not clearly affect the development or progression of LV hypertrophy. The maintenance of [Hb] above 100 g/L for many patients in group B might have been attributable to the relative preservation of renal function.Chronic kidney disease (CKD) is widespread in the community, with a prevalence far exceeding previous estimates (1). Many studies examining mortality and morbidity rates among patients with CKD have identified high rates of cardiovascular events. When even mild renal insufficiency is associated with other risk factors for cardiovascular disease, the risk of subsequent cardiovascular events is significantly increased (2-10). The effect of mild renal insufficiency (serum creatinine levels of Ͼ124 M) on cardiovascular risk is possibly also independent of other known risk factors and treatment (11)(12)(13)(14)(15). For patients established on dialysis, cardiovascular disease is responsible for up to 50% of the all-cause mortality rate (16,17). It is therefore important to attempt to reduce the incidence of cardiovascular events with risk factor modification before the onset of dialysis.Left ventricular (LV) hypertrophy (LVH) is recognized as a powerful independent predictor of death and morbidity in the dialysis population, together with anemia, hypertension, malnutrition, hyperparathyroidism, and an elevated calcium-phos-