#2011 Reduced hospitalisation or emergency department visits with long- versus short-term SZC in patients with history of hyperkalaemia: GALVANIZE Outcomes
Authors: Agiro Abiy , Smith Jess , Greatsinger Ali , Mu Fan , Cook Erin E , Reichert Emily , Colman Ellen , Malhotra Arun , Rhee Connie 
Published: May 2024

Abstract

Background and Aims
Hyperkalaemia is associated with increased healthcare resource use and often requires long-term management. The GALVANIZE Outcomes study is a comparison of hyperkalaemia-related and all-cause hospitalisations or emergency department visits between matched patients treated with long- or short-term sodium zirconium cyclosilicate (SZC), using real-world data. This analysis evaluated outcomes in patients with a history of hyperkalaemia.

Method
A large US insurance claims database (from HealthVerity) was used to identify adults who initiated SZC (index date) in the outpatient setting between 1 January 2019 and 30 June 2022, with a diagnosis of hyperkalaemia within 6 months prior to the index date. Exclusion criteria included patients without either 6 months of continuous insurance coverage prior to index, or 30 days of continuous insurance coverage post-index. Patients were followed to the earliest of 6 months post-index, loss of coverage, end of the study period or (re) initiation of a potassium binder. Patients with short-term SZC use (≤30 days) were exact and propensity score–matched to patients with long-term SZC use (&gt;90 days). Hyperkalaemia-related hospitalisations and emergency department visits were identified by the International Classification of Diseases (tenth revision) diagnosis code for hyperkalaemia. Rates of the composite outcomes of the number of hyperkalaemia-related hospitalisations or emergency department visits (primary endpoint) and all-cause hospitalisations or emergency department visits (exploratory endpoint) per person-year (PPY) were compared during follow-up using generalised estimating equations.

Results
Among 2088 eligible matched pairs with a history of hyperkalaemia, the mean age was 63.8 years and 41.4% of the population was female. Most patients (94.9%) had a diagnosis of chronic kidney disease, which mostly included stage 3 (27.3%), stage 4 (25.4%) and stage 5/end-stage (38.7%) kidney disease, while one-third (34.4%) had a diagnosis of heart failure irrespective of ejection fraction. The median (interquartile range) duration of follow-up was 183 (183, 183) days for long-term SZC and 169 (82, 183) days for short-term SZC. During follow-up, in patients with a history of hyperkalaemia, those with long-term SZC use had a 43% lower rate of hyperkalaemia-related hospitalisations or emergency department visits than matched patients with short-term SZC use (rate [95% confidence interval] PPY: 0.89 [0.79–0.98] vs 1.56 [1.35–1.76]; P&lt;0.001) (Fig. 1). Similarly, patients with long-term SZC use had a 35% lower rate of all-cause hospitalisations or emergency department visits than those with short-term SZC use (2.63 [2.44–2.82] vs 4.05 [3.71–4.40]; P&lt;0.001]) (Fig. 2).

Conclusion
In this real-world study of patients with hyperkalaemia, individuals treated with long-term SZC experienced significantly lower rates of hyperkalaemia-related and all-cause hospitalisations or emergency department visits compared with matched patients with short-term SZC use.