#5810 SELECTED CARDIOVASCULAR (CV)/NON-CV EVENT RATES IN NON-DIALYSIS-DEPENDENT PATIENTS TREATED WITH ESAS IN US MEDICARE (2017–2019), BY CKD STAGE
Authors: Wetmore James , Rouette Julie , Guo Haifeng , Requena Gema , Li Suying , Mu George , Ma Liyuan , Fairburn-Beech Jolyon , Richards Anna , Gilbertson David , Wetten Sally , Liu Jiannong 
Published: June 2023

Abstract

Background and Aims
The safety and efficacy of daprodustat in non-dialysis-dependent chronic kidney disease (CKD) patients have been reported in the ASCEND-ND trial [1]. However, CKD stage may affect both the need for anemia treatment as well as outcomes, including potential safety events for anemia treatment. This study describes cardiovascular (CV) and non-CV event rates by CKD stage among patients treated with erythropoietin-stimulating agents (ESAs) in the US Medicare population.

Method
Using Medicare data for all fee-for-service enrollees, we conducted a retrospective cohort study of patients who had diagnosis of CKD stages 3, 4, or 5 and a first use of ESA in 2017–2019. CKD stage was identified by ICD-10 codes; ESA use was derived using Healthcare Common Procedure Coding System (HCPCS) codes. The date of first ESA use was the index date and CKD stage was defined as the most recent diagnosis on or before index date. We further required patients to have at least 12 continuous months of Medicare Parts A and B coverage (also used as a washout period to identify new ESA users) prior to, and be aged ≥66 years on, the index date. Patients with a history of kidney transplant or who had cancer during the year prior, and those who had a hospitalization for heart failure (HF), myocardial infarction (MI), or stroke in the 4 weeks before, the index date were excluded. Patients were followed from index date to the earliest date of death, loss of Medicare coverage, kidney transplantation or dialysis, or December 31, 2019.
Both CV (all-cause death, HF, MI, stroke, thromboembolic events [TEEs], MACE [death, stroke, MI], and MACE+HF) and non-CV (cancer, gastric erosions, ocular events, seizures, and serious infections) events were ascertained, derived from Medical claims using ICD-10 diagnosis, HCPCS, and Current Procedural Terminology codes in the follow-up period. HF, MI, stroke, and serious infection were defined as inpatient events. First event rates were calculated separately by CKD stage, expressed as number of events per 100 patient-years during the follow-up period.

Results
This study cohort included 50,206 patients; 22,332 had stage 3, 19,177 stage 4, and 8,697 stage 5 CKD at the index date. Median follow-up time was 11.5 months for patients with CKD stage 3, 8.9 months for patients with stage 4, and 3.7 months for patients with stage 5 CKD. Patients with higher (worse) CKD stages were slightly younger (mean ages for stages 3, 4, and 5 were 79.7, 79.1, and 76.8 years); with increasingly more males (42.9%, 45.1%, and 48.5%), increasingly more individuals of non-Hispanic Black race (14.2%, 15.7%, and 19.6%), with lower income (indicated by Medicare/Medicaid dual enrolment and Medicare Part D low-income subsidy), and lower proportion of comorbidities. Rates were higher for most CV events in patients with higher (worse) CKD stages (Table): death rates were 19.5, 22.1, and 28.1 per 100 patient-years for stages 3, 4, and 5, respectively; MI rates were 2.2, 2.9, and 3.2; HF rates were 12.5, 17.2, and 19.0; MACE rates were 22.0, 25.4, and 31.8; and MACE+HF rates were 31.0, 38.7 and 47.8, respectively. Rates of stroke were similar across CKD stages; but no pattern for TEE. For non-CV events, higher (worse) CKD stage had higher rates of first ocular events (17.2, 23.3, and 27.1) and seizures (2.3, 2.7, and 3.4), but lower rates of cancer (21.8, 14.2, and 10.2) and, within this, hematological malignancies (10.4, 4.11 and 2.3).

Conclusion
Medicare-covered ESA-treated patients with higher CKD stage had higher rates for most events assessed, while malignancy rates were lower. These findings may provide important context when assessing US event rates in non-dialysis-dependent CKD patients. Further investigation could clarify some of the differences between stages, such as rates of malignancy. Rates were reported as crude (unadjusted) and so should be interpreted with caution. Limiting the analysis to ESA-treated patients may have resulted in different event rates than would be expected to occur in the general CKD population. Funding: GSK (study 217316).