Optimized Or Maximized Dose Of Mineralocorticoid Receptor Antagonists Among Patients Initiating Outpatient Sodium Zirconium Cyclosilicate Therapy

Abstract

Introduction

Renin-angiotensin-aldosterone system inhibitor (RAASi) use can exacerbate hyperkalemia, especially in patients with cardiorenal conditions. Sodium zirconium cyclosilicate (SZC) has been previously shown to enable patients with hyperkalemia to continue RAASi; however, the level of dose optimization or maximization of RAASi after the initiation of outpatient SZC therapy is not well described, particularly among patients receiving mineralocorticoid receptor antagonists (MRA).

Methods

Using data from a large US insurance claims database from 7/2018-12/2022, adults who initiated SZC in the outpatient setting with a ≥7 day overlap with a RAASi (index) and ≥1 MRA fill in the 6-month follow-up period were selected. MRA optimization (≥50% of target dose) or maximization (≥100% of target dose) per guidelines were described during follow-up. The target dose for both spironolactone and eplerenone was 50 mg daily. Predictors of MRA optimization and maximization were assessed using separate multivariable logistic regression models.

Results

A total of 395 patients with MRA use after SZC initiation met the inclusion criteria, of whom 341 (86%) had an optimized MRA dose and 129 (33%) had a maximized MRA dose during follow-up. Patients had a mean age of 66 years and 63% of the sample was male. Common comorbidities included hypertension (91%), stage 1-4 or unspecified stage chronic kidney disease (CKD; 81%), diabetes (72%), and heart failure (53%). Predictors of MRA optimization included any vasodilator use (Figure 1). Predictors of MRA maximization included liver disease, stage 3 or stage 4 CKD vs. no CKD, and the absence of heart failure (Figure 2).

Conclusions

Among this real-world sample of patients taking a RAASi, most patients with hyperkalemia optimized their MRA dose and one-third maximized their MRA dose after initiating SZC in the outpatient setting. Certain clinical characteristics are significant predictors of the optimization and maximization of MRA dose.

Funding

AstraZeneca