#1481 Renin-angiotensin-aldosterone system inhibitor (RAASi) optimisation after initiating outpatient SZC therapy: the GALVANIZE RAASi real-world study
Authors: Agiro Abiy , Chen Jingyi , Greatsinger Ali , Mu Fan , Cook Erin E , Sundar Manasvi , Zhao Angela , Colman Ellen , Malhotra Arun , Rhee Connie 
Published: May 2024

Abstract

Background and Aims
Hyperkalaemia often occurs in patients with comorbidities that are treated with renin-angiotensin-aldosterone system inhibitors (RAASi), e.g., chronic kidney disease (CKD), heart failure or resistant hypertension. However, RAASi use can exacerbate hyperkalaemia. The GALVANIZE RAASi real-world study evaluated RAASi dose optimisation or maximisation following initiation of sodium zirconium cyclosilicate (SZC) therapy in the outpatient setting.

Method
A large US insurance claims database (from HealthVerity), spanning July 2018–December 2022, was used to identify adults initiating SZC therapy in the outpatient setting, who had an overlapping RAASi prescription fill (≥7 days; index date) and another RAASi prescription fill, within 90 days following the end of the index RAASi episode, during the 6-month follow-up period. Exclusion criteria included patients with a diagnosis of CKD Stage 5 or end-stage kidney disease, treatment with haemodialysis, or the absence of 6 months of continuous insurance coverage prior to, and after, the index date. During a 6-month follow-up period, the proportions of patients with an optimised (≥50% maximum dose; primary endpoint) or maximised (≥100% maximum dose; secondary endpoint) RAASi dose, per label indication, were assessed in the overall population and in sub-studies of patients with a diagnosis of CKD, heart failure, or hypertension (International Classification of Diseases, tenth revision). Diagnosis of hypertension with ≥3 classes of antihypertensive medications (including a diuretic) was defined as resistant hypertension. Multivariable logistic regression was used to identify factors associated with optimised or maximised doses of RAASi.

Results
Among 2973 eligible patients, mean age was 66.3 years and 41.6% of the population was female. Most patients had Stage 1 to 4 CKD (85.7%), including 46.2% with stage 3 CKD, and 33.0% with stage 4 CKD. Heart failure or resistant hypertension was present in 29.6% and 30.4% of patients, respectively. In the overall population, almost two-thirds of patients (63.7%) optimised their RAASi dose and over a quarter of patients maximised their RAASi dose (27.2%) during follow-up. Factors associated with optimised or maximised doses of RAASi are shown in Figs 1 and 2, respectively. In the sub-studies of patients with CKD (n = 2549), heart failure (n = 879) or resistant hypertension (n = 903), RAASi optimisation was achieved in 63.5%, 63.9% and 72.6% of patients, respectively, and RAASi maximisation was reached in 27.0%, 27.5% and 36.1% of patients, respectively.

Conclusion
In this real-world study of patients with hyperkalaemia who were receiving RAASi treatment, most individuals who initiated outpatient SZC therapy achieved RAASi dose optimisation overall and across the comorbidity-defined sub-studies evaluated, and more than a quarter of patients achieved dose maximisation within 6 months.