Time-dependent resistance to erythropoiesis-stimulating agent and mortality in hemodialysis patients in the Japan Dialysis Outcomes and Practice Patterns Study.

BACKGROUND/AIMS: Resistance to erythropoiesis-stimulating agent (ESA) is associated with mortality in hemodialysis (HD) patients. Time-dependent variability of ESA resistance has been not investigated adequately, although consistently high ESA resistance is expected to be a high risk for mortality. Our aim, therefore, was to investigate consistently high ESA resistance as an independent predictor of mortality in HD patients.
METHODS: This study evaluated 2,104 Japanese HD patients in the Dialysis Outcomes and Practice Patterns Study (DOPPS) III. ESA resistance index (ERI) was defined as the weekly weight-adjusted dose of ESA divided by hemoglobin concentration. The average ERI was calculated from ERI levels every 4 months throughout the observation period for each patient. To assess the size of the fluctuation in average ERI during the observation periods according to ERI quartiles at the enrollment periods, six patient groups were defined on the basis of patterns of ERI level fluctuation: low-low (Low), intermediate-intermediate (Intermediate), high-high (High), low-intermediate, intermediate-high, and low-high.
RESULTS: The number of deaths among the patients was 227 (10.8%), which included 113 (5.4%) cases of cardiovascular disease (CVD). In multivariate analysis after adjustment for age, albumin, C-reactive protein, comorbidities, etc., the High group was independently and significantly related to all-cause and CVD-related mortality (OR = 2.33, 95% CI: 1.33-4.07, p = 0.002, and OR = 2.09, 95% CI: 1.05-4.14, p = 0.035, respectively).
CONCLUSION: Factoring out fluctuating ERI increases the ability of consistently high ERI levels as an independent risk factor for all-cause and CVD mortality in HD patients.