Kidney Week

Abstract: TH-PO700

Examining the Magnitude of Erythropoiesis-Stimulating Agent Hyporesponsiveness in Hemodialysis Patients

Session Information

• Anemia and Iron Metabolism
  November 03, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
  Abstract Time: 10:00 AM - 12:00 PM

Category: Anemia and Iron Metabolism

• 200 Anemia and Iron Metabolism

Authors

• Weinhandl, Eric D., Chronic Disease Research Group, Minneapolis, Minnesota, United States

Eric D. Weinhandl,

• Hwang, Yunji, Amgen Inc, Thousand Oaks, California, United States

Yunji Hwang,

• Gilbertson, David T., Chronic Disease Research Group, Minneapolis, Minnesota, United States

David T. Gilbertson,

• Petersen, Jeffrey, Amgen Inc, Thousand Oaks, California, United States

Jeffrey Petersen,

Background

Anemia is common in patients undergoing maintenance hemodialysis (HD) and is treated with erythropoiesis-stimulating agents (ESAs) and intravenous iron. ESA hyporesponsiveness is an oft-cited unmet medical need, but the scope of the problem is obscured by complex statistical quantities, including the erythropoietin resistance index (ERI). We analyzed a contemporary, nationally representative cohort to describe anemia-related parameters of HD patients with high ERI and/or chronically low hemoglobin (Hb).

Methods

We analyzed CROWNWeb records of HD patients in 2016-2019. The study cohort included 6-month patient-intervals characterized by treatment with either epoetin alfa (EPO) or darbepoetin alfa (DPO), monthly measurements of Hb, and at least one measurement of transferrin saturation (TSAT). We stratified patient-intervals by the cross-classification of normal vs high ERl (definition: ≥20 EPO-equivalent IU/wk/kg/g/dL, where 1 mcg DPO = 250 IU EPO) and transiently vs chronically low Hb (definition: Hb <10 g/dL in every month of the interval). In each stratum, we estimated median values of weekly ESA dose, Hb, ERI, and TSAT.

Results

We identified 7,824,640 patient-intervals. Prevalence of high ERI was 17.2% in single patient-months and 15.6% during 6-month patient-intervals. In both cases, ERI was strongly correlated with weekly ESA dose (R² = 0.87). In contrast, prevalence of Hb <10 g/dL was 23.0% in single patient-months, whereas prevalence of chronically low Hb was 2.5% during 6-month patient-intervals (table). Among 15.6% of patients with high ERI, 13.8% experienced only transiently low Hb, with median Hb of 10.1 g/dL and median TSAT of 25.0%. Among 2.5% of patients with chronically low Hb, 1.8% experienced high ERI, with median TSAT of 23.0%.

Conclusion

Prevalence of high ERI in HD patients exceeds 15%, mostly due to the scale of ESA dosing, but this overstates the prevalence of chronic anemia hyporesponsive to treatment. Lower TSAT is common in patients with high ERI and/or chronically low Hb, suggesting potential iron deficiency.

Funding

• Commercial Support – Amgen Inc.