Critical appraisal of randomized controlled trials of anemia correction in patients with renal failure

Recent randomized controlled trials (RCTs) have reported risks and benefits in the correction of anemia using erythropoietin-stimulating agents (ESAs) in patients with predialysis chronic kidney disease (CKD) or end-stage renal disease. The purpose of this review is to critically appraise the RCTs most relevant to clinical decision-making.

The Trial to Reduce cardiovascular Events with Aransep Therapy (TREAT) is the biggest and best designed RCT performed so far, enrolling 4038 diabetic patients with CKD in a double-blind, placebo-controlled trial. Comparing the high hemoglobin (Hb) darbopoietin group with placebo, it reported no difference in cardiac and renal outcomes, a significantly increased risk of stroke, and modest improvement in fatigue and transfusion rate. Meta-analysis demonstrated that correction of anemia with ESA was associated with a significantly increased risk of hypertension and vascular access clotting and an increased risk of death that approached statistical significance. Quality-of-life improvements appeared to maximize in the target Hb range of 10-12 g/dl.

Treatment of renal anemia using ESAs to target Hb higher than 13 g/dl is harmful. Treatment of Hb below 9 g/dl provides substantial transfusion and quality-of-life benefits, but safety is unknown. Target Hb levels of 10-12 g/dl seem reasonable, but increasing ESA doses in hyporesponsive patients to achieve a specific target is not.