Abstract

Introduction: Patients receiving renin-angiotensin-aldosterone system inhibitors (RAASi) are at increased risk of developing hyperkalemia (HK). Sodium zirconium cyclosilicate (SZC) is used to treat HK, but the impact of duration of SZC on healthcare resource utilization (HRU) in RAASi users is unknown. The GALVANIZE Outcome study compared HK-related HRU among RAASi users between long-term and short-term SZC users. Methods: Adults with ≥1 outpatient prescription for SZC (index date) and ≥1 RAASi prescription spanning the index date were identified from a large US insurance claims database (7/2018-12/2022) and were stratified based on duration of SZC use. Long-term SZC users (>90 days) and short-term SZC users (≤30 days) were exactly and propensity score matched on key baseline characteristics. Rates of HK-related hospitalizations or emergency department (ED) visits, HK-related ED visits, and HK-related hospitalizations were compared during follow-up from index to the earliest of 6 months post-index, end of data availability, other potassium binder use, or re-initiation of SZC post-discontinuation. Results: Among 1,586 matched pairs, the mean age was 65.5 years, 41.0% of patients were female, and most patients had any stage chronic kidney disease (91.9%), hypertension (90.8%), and diabetes (73.4%). Also, 30.0% of patients had heart failure. The most used RAASi therapies at index were angiotensin-converting enzyme inhibitors (57.3%) and angiotensin-receptor blockers (56.3%). Patients with long-term SZC use had a 44% lower rate of HK-related hospitalizations or ED visits, a 41% lower rate of HK-related hospitalizations and a 52% lower rate of HK-related ED visits than patients with short-term SZC use during follow-up (all p<0.01; Figure 1). Conclusions: Among patients with RAASi and SZC therapy use, long-term SZC use was associated with significantly lower rates of HK-related HRU compared to matched patients with short-term SZC use. Funding: AstraZeneca