Patiromer Treatment in Patients With CKD, Hyperkalemia, and Hyperphosphatemia: A Post Hoc Analysis of 3 Clinical Trials

Randomized Trial of Patiromer on Efficacy to Reduce Episodic Hyperkalemia in Patients with ESKD Treated With Hemodialysis

Introduction

Individuals with end-stage kidney disease (ESKD) maintained on hemodialysis (HD) carry a high risk of cardiac arrhythmias. This risk is heightened by episodic hyperkalemia. The purpose of the study was to investigate whether patiromer administered daily reduced episodes of hyperkalemia in those with ESKD who receive HD, and to explore whether prescription of patiromer reduced the number of significant arrhythmia events.

Methods

This was a prospective, randomized, open-label trial. Eligible patients with ESKD on HD were identified. Participants were randomized 1:1 to patiromer versus usual care. Those randomized to patiromer were administered the medication daily, and the dose was titrated based on serum potassium concentrations at the start of weeks 1, 2, and 3. All participants received 7-day continuous cardiac monitors at baseline and at week 4.

Results

Of the 33 participants who were randomized, 1 withdrew due to adverse symptoms, and 1 withdrew due to pregnancy, leaving 31 in our analytic cohort. The mean age of randomized participants was 56 years, 55% were male, 81% were Black, and 10% were Hispanic/Latino. In week 4, the number of episodes of serum potassium ≥ 5.5 mEq/l was 13 in the patiromer group and 41 in the control group; with median number of episodes of hyperkalemia in the patiromer group significantly lower than that of control group (0 vs. 3, P = 0.024). In week 4 continuous cardiac monitors, 6 participants had > 1000/24 h premature ventricular contractions, 5 had no sustained ventricular tachycardia (VT), 3 had atrial fibrillation, and 1 had bradycardia, with no significant differences between the groups.

Conclusion

Patiromer administered daily reduced the frequency of hyperkalemia in study participants with ESKD who receive thrice-weekly HD. Larger studies are needed to determine whether patiromer reduces significant cardiac events.

Risk of Serious Adverse Gastrointestinal Events with Potassium Binders in Hospitalized Patients: A National Study

BACKGROUND

Concerns about serious adverse gastrointestinal (GI) events with sodium polystyrene sulfonate (SPS) led to development of two new potassium binders, patiromer and sodium zirconium cyclosilicate (SZC), for treatment of hyperkalemia.

OBJECTIVE

To compare risk of intestinal ischemia/thrombosis or other serious GI events associated with SPS, patiromer, or SZC in hospitalized patients.

DESIGN

Retrospective cohort study.

PARTICIPANTS

National sample of 3,144,960 veterans hospitalized 2016-2022 in the U.S. Department of Veterans Affairs Healthcare System.

MAIN MEASURES

Demographics, comorbidities, medications and outcomes were ascertained from the VA Corporate Data Warehouse. Exposures were SPS, patiromer, SZC. Outcomes were 30-day intestinal ischemia/thrombosis, and a composite of intestinal ischemia/thrombosis, peptic ulcer/perforation or bowel resection/ostomy.

KEY RESULTS

Potassium binders were used during 39,270 (1.3%) hospitalizations: SPS = 30,040 (1.0%), patiromer = 3,750 (0.1%), and SZC = 5,520 (0.2%). Intestinal ischemia/thrombosis occurred with 106/30,040 (0.4%) SPS, 12/3750 (0.3%) patiromer and 24/5520 (0.4%) SZC, vs. 6998/3,105,650 (0.2%) without potassium binder. Adjusted odds ratios (aOR) were 1.40 [95% CI, 1.16 to 1.69] with SPS, 1.36 [CI, 0.79 to 2.36] with patiromer, and 1.78 [CI, 1.21 to 2.63] with SZC exposures. Composite GI adverse events occurred with 754/30,040 (2.5%) SPS, 96/3750 (2.6%) patiromer, 2.6% SZC, vs. 144/5520 (2.4%) without binder; aOR were 1.00 [CI, 0.94 to 1.08] with SPS, 1.08 [CI, 0.89 to 1.32] with patiromer, and 1.08 [CI, 0.93 to 1.27] with SZC exposures. No statistical difference in intestinal ischemia/thrombosis between each new agent and SPS was seen (p = 0.274 for SPS vs. SZC; p = 0.916 for SPS vs. patiromer).

CONCLUSION

Risk of intestinal ischemia/thrombosis or other serious adverse GI events was low and did not differ across three potassium-binding drugs.

Nephrology: What You May Have Missed in 2023

This article highlights a selection of important nephrology studies published in 2023 that have relevance for nonnephrologist physicians. Four studies examined progression of chronic kidney disease or cardiovascular disease with respect to finerenone use, magnesium supplementation, iron markers, and COVID-19. Two studies examined treatments to improve specific aspects of chronic kidney disease management, including daprodustat to address anemia and patiromer to address hyperphosphatemia. One study showed that acetazolamide added to loop diuretics increased diuresis in acute decompensated heart failure across a wide range of renal function. Another study found that once-daily hydrochlorothiazide did not prevent kidney stone recurrence. Finally, an antibiotic stewardship intervention safely reduced antibiotic prescribing for suspected urinary tract infection in frail older adults.

Management of Hyperkalemia in Patients with Chronic Kidney Disease Using Renin Angiotensin Aldosterone System Inhibitors

PURPOSE OF REVIEW

Use of renin-angiotensin-aldosterone system (RAAS) inhibiting medications is critical in the prevention of cardiovascular disease and kidney function decline in patients with chronic kidney disease (CKD); however, these agents can lead to hyperkalemia, an electrolyte disorder associated with risk of arrythmia, conduction disorders, and increased overall mortality. Discontinuation, or reduction of dose, of RAAS inhibitor therapy in hyperkalemic patients with CKD can lead to loss of kidney and cardiovascular protection afforded by these medications. Given the high prevalence of hyperkalemia among patients with CKD utilizing RAAS inhibitors, clear management principles are critical to minimize risk and maximize benefit when facing this clinical dilemma.

RECENT FINDINGS

Strategies to mitigate hyperkalemia that do not interfere with optimal RAAS inhibitor therapy should be prioritized when managing potassium elevation in patients with CKD. These strategies include discontinuing non-RAAS inhibitor medications known to cause hyperkalemia, correction of metabolic acidosis, and maximization of medication therapies that lower serum potassium, including diuretics and sodium-glucose cotransporter-2 (SGLT-2) inhibitors. Initiation of potassium exchange resins should also be considered to allow for sustained RAAS inhibitor utilization. An approach which employs multiple strategies concurrently is important to mitigate hyperkalemia and maintain long-term use of RAAS-inhibitors. Persistence of RAAS inhibitor use in patients with CKD is important to slow kidney function decline, delay onset of dialysis or the need for kidney transplant, and prevent adverse cardiovascular outcomes. When hyperkalemia develops among patients with CKD utilizing a RAAS inhibitor, a deliberate effort to reduce serum potassium levels using an approach that allows for continuation of maximally dosed RAAS inhibitor therapy is important. Patient education and engagement in the potassium management process is important for sustained success.