Anemia management and treatment response in patients on hemodialysis:: the MAR study

Background: Anemia management guidelines describe the importance of anemia as a risk factor in hemodialysis and the need for clinical prospective studies focused on this role of anemia. Response to treatment with iron and epoetin is multifactorial, and results are still far from the targets set by the guidelines. The Morbidity and Mortality Anemia Renal study (MAR) is a multicenter prospective cohort study of hemodialysis (HD), designed to assess the burden of anemia on morbidity and mortality. We report here a cross-sectional analysis of the management of anemia, and response-to-treatment factors. Methods: A total of 1,710 patients were included (60% male, mean age 64.4 +/- 13.6 years, mean 16.2 +/- 11.1 months on HD) with a high comorbidity (hypertension 75.8%, diabetes 25.9%, heart failure 13.9% and coronary disease 16.7%) and a mean Charlson Index of 6.5 +/- 2.3. Results: There were 28.7% of patients who had started epoetin before end-stage renal disease (pre-ESRD), 81.4% of patients displayed Hb < 11 g/dL when initiating HD with a mean Hb of 9.7 g/dL. Only 67.9% of prevalent HD patients attained a hemoglobin (Hb) level above 11 g/dL, 89.5% achieved a ferritin level above 100 ng/mL, 76.7% a transferrin saturation index (TSI) above 20%, and 61.1% met all 3 objectives. The multivariate analysis identified the following risk factors for Hb < 11g/dL: low albumin (odds ratio, OR = 1.75), HD efficacy below objectives (OR = 1.44) and female sex (OR = 1.36), corrected for comorbidity, epoetin treatment, transfusion, surgery or hospital admission. Conclusions: As compared with previous surveys, we found an improved but still inadequate anemia management in Spanish HD patients. Our results are comparable with those of Euro-DOPPS. Several modifiable factors related to a lower Hb concentration were assessed.