# Anemia Treatment and Its Clinical Implications in Patients Receiving Hemodialysis Hyporesponsive to Erythropoietin-Stimulating Agents

## TL;DR

This study finds that patients on hemodialysis with anemia unresponsive to ESA treatment face higher risks of complications and hospitalizations.

## Contribution

The study identifies higher clinical burden and mortality in ESA hyporesponsive hemodialysis patients using real-world data.

## Key findings

- ESA hyporesponsive patients had higher red blood cell transfusion rates and hospitalizations.
- They experienced more cardiovascular events and gastrointestinal erosions.
- Mortality rates were significantly higher in ESA hyporesponsive patients.

## Abstract

Anemia, highly prevalent among patients receiving maintenance dialysis, may be associated with adverse outcomes. This study describes the patient characteristics, anemia treatment patterns, clinical event rates, and health care resource utilization of patients receiving hemodialysis (HD) in the United States and in a subpopulation of patients hyporesponsive to erythropoietin-stimulating agents (ESAs).

Using data from the US Renal Data System, a retrospective, population-based descriptive cohort study of adults with Medicare Parts A and B coverage receiving maintenance HD was conducted.

ESA hyporesponsiveness was defined as ESA Resistance Index ≥2 (ESA units/kg/wk/g hemoglobin/L) or ESA dose ≥450 U/kg/wk (within 8 weeks of index (January 1, 2018).

Anemia treatments and clinical events were assessed using medical claims during follow-up, until death, loss of Medicare, kidney transplantation, or December 31, 2019.

Outcome rates were calculated as number of events divided by follow-up time with 95% confidence intervals based on Poisson distribution.

Of the overall prevalent HD population (N = 209,408), 20,223 were ESA hyporesponders. Relative to the overall prevalent HD population, the ESA hyporesponder subpopulation had a higher rate of red blood cell transfusion events (91.1 [95% CI, 90.1-92.2] vs 32.4 [95% CI, 32.2-32.6] per 100 person-years [PY]), thromboembolic events (80.7 [95% CI, 79.3-82.2] vs 71.0 [95% CI, 70.6-71.4] per 100 PY), major adverse cardiovascular events (30.2 [95% CI, 29.6-30.9] vs 20.3 [95% CI, 20.2-20.5] per 100 PY), gastrointestinal erosions (61.8 [95% CI, 60.6-63.0] vs 40.2 [95% CI, 40.0-40.5] per 100 PY), and all-cause mortality (26.2 [95% CI, 25.6-26.8] vs 16.9 [95% CI, 16.8-17.1] per 100 PY). Hospitalizations occurred more frequently in the ESA hyporesponder subpopulation (2.45 vs 1.56 per PY) than in the overall prevalent HD population.

This study was not designed to determine causality.

The ESA hyporesponder subpopulation had a high burden of red blood cell transfusion use, clinical events, and health care resource utilization.

Most patients receiving dialysis have anemia, which requires treatment. This study analyzed information on patients receiving maintenance hemodialysis in the United States and a subgroup of these patients whose anemia responded poorly to erythropoietin-stimulating agents (ESAs). Relative to the overall population of patients, those whose anemia responded poorly to ESAs had more frequent treatment with red blood cell transfusion, more hospitalizations, higher cardiovascular and non-cardiovascular health complications, and higher rates of death. The findings highlight the importance of understanding outcomes in patients whose anemia responded poorly to ESAs and the need to treat these patients appropriately, which may help inform future resource planning for the health care system.