Long-term Patiromer Use and Outcomes Among US Veterans With Hyperkalemia and CKD: A Propensity-Matched Cohort Study

Rationale & Objective: Patiromer is a potassium binder approved for the long-term management of hyperkalemia. Although patiromer use among patients with advanced chronic kidney disease (CKD) has been shown to reduce the discontinuation of renin-angiotensin-aldosterone system inhibition therapy, it remains unclear whether patiromer can improve clinical outcomes. The aim of this study was to examine the association of long-term patiromer use with clinical outcomes among hyperkalemic patients with CKD.Study Design: This was a longitudinal observa-tional study.Setting & Participants: We evaluated a national cohort of 854,217 US Veterans who had at least 1 serum potassium measurement of >= 5.1 mEq/L and were treated at US Department of Veterans Affairs health care facilities between January 2016 and September 2019.Exposure: The exposure was long-term patiromer use.Outcomes: The outcomes were as follows: (1) composite endpoint of kidney failure with replace-ment therapy (KFRT) or all-cause death and (2) all-cause death including the post-KFRT period.Analytical Approach: Cox proportional Fine -Gray subdistribution hazard models were used in a propensity-matched cohort.Results: Among 2,004 patients who ever used patiromer during the study period (0.2% of the cohort), 666 met the criteria for long-term patiromer use. We matched 308 long-term patiromer users to 308 nonusers based on propensity scores. The median estimated glomerular filtration rate was 23.5 mL/min/1.73m2, and the median potassium level was 5.2 mEq/L. Approximately 45% were on renin-angiotensin system inhibitor(s) at baseline. During follow-up, 93 patients developed KFRT, and 134 patients died. Long-term patiromer users, when compared to nonusers, experienced a 26% lower risk of the composite outcome (HR, 0.74; 95% CI, 0.53-1.01; P = 0.06) and a 41% lower risk of all-cause mortality (HR, 0.59; 95% CI, 0.41-0.84; P = 0.003).Limitations: The study cohort included mostly male veterans with relatively short follow-up periods.Conclusions: Long-term patiromer use was asso-ciated with a lower risk of all-cause mortality among patients with CKD and hyperkalemia. Long-term potassium binder use for hyperkalemia may improve clinical outcomes in CKD.