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Study on Sodium Zirconium Cyclosilicate for Improving Heart Failure Treatment in Patients with High-Risk Hyperkalemia

Verified siteRegistered drugNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the effects of a treatment for patients with heart failure, specifically those who are at risk of or experiencing high potassium levels in the blood, a condition known as hyperkalemia. The treatment being tested is called Sodium Zirconium Cyclosilicate, also known by its code name SZC. This medication is being compared to a placebo to see if it can help optimize the use of another type of heart failure medication called mineralocorticoid receptor antagonists (MRA), which are often used to manage heart failure symptoms.

The purpose of the study is to evaluate the effectiveness and safety of Sodium Zirconium Cyclosilicate in helping patients maintain a stable dose of their heart failure medication without experiencing high potassium levels. Participants in the study will receive either the Sodium Zirconium Cyclosilicate or a placebo, and their progress will be monitored over a period of time to assess how well the treatment works in maintaining normal potassium levels and improving heart failure management.

Throughout the study, researchers will also look at how the treatment affects the quality of life for patients and how well they tolerate the medication. The study aims to provide valuable information on whether Sodium Zirconium Cyclosilicate can be a beneficial addition to the treatment plan for patients with heart failure who are at risk of high potassium levels, potentially leading to better management of their condition.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Upon joining the study, the patient provides signed informed consent. This is a necessary step before any study-specific procedures can begin.

  2. Step 2

    Initial assessment

    The patient undergoes an initial assessment to confirm eligibility. This includes checking heart function with an echocardiogram and reviewing current heart failure treatment. The patient must have a left ventricular ejection fraction (LVEF) of 40% or less and be on optimal treatment for heart failure.

  3. Step 3

    Randomization

    The patient is randomly assigned to receive either sodium zirconium cyclosilicate or a placebo. This is done to compare the effects of the medication with no active treatment.

  4. Step 4

    Medication administration

    The patient takes the assigned medication orally. The dosage and frequency are determined by the study protocol, and the patient is monitored for any side effects or changes in health status.

  5. Step 5

    Monitoring and follow-up

    Throughout the study, the patient attends regular follow-up visits. These visits include monitoring potassium levels and heart function to ensure safety and assess the effectiveness of the treatment.

  6. Step 6

    End of study evaluation

    At the end of the study, the patient undergoes a final evaluation. This includes assessing the ability to maintain or increase the dose of mineralocorticoid receptor antagonists (MRA) and ensuring potassium levels remain within the normal range.

Who can join the trial?

10 criteria

  • You must sign a form to show you agree to participate before any study procedures begin.
  • You need to be over 18 years old, regardless of gender.
  • Your heart's ability to pump blood, known as the left ventricular ejection fraction (LVEF), should be 40% or less. This should be confirmed by an ultrasound of the heart done in the last two years, even if your heart function has improved since then.
  • You should have symptoms of heart failure that fall into classes II to IV according to the New York Heart Association (NYHA) classification, which measures the severity of heart failure symptoms.
  • Your heart failure should be stable, as determined by the doctor in charge. You can join the study as an outpatient or shortly after being discharged from the hospital.
  • You should be on the best possible treatment for heart failure, which may include medications like ACE inhibitors, ARBs, ARNIs, beta-blockers, and SGLT2 inhibitors, as decided by your doctor.
  • Your treatment with mineralocorticoid receptor antagonists (MRA) should be less than ideal, meaning you are either not using them or taking 25 mg or less daily.
  • You must meet one of the following conditions related to hyperkalemia, which is a high level of potassium in the blood:
    • You had high potassium levels (above 5.0 mmol/L in serum or above 4.8 mmol/L in plasma) during MRA treatment in the last 24 months, and your current levels are 5.0 mmol/L or less in serum or 4.8 mmol/L or less in plasma.
    • Your current potassium levels are between 4.5-5.0 mmol/L in serum or 4.3-4.8 mmol/L in plasma, and you have a potential risk of high potassium as indicated by a kidney function test called eGFR showing 30-45 ml/min/1.73 m².
    • Your current potassium levels are between 5.1-5.9 mmol/L in serum or 4.9-5.7 mmol/L in plasma.

Who cannot join the trial?

3 criteria

  • Patients with **high-risk hyperkalemia** cannot participate. Hyperkalemia means having too much potassium in the blood, which can be dangerous.
  • Patients with **heart failure** are excluded. Heart failure is a condition where the heart doesn't pump blood as well as it should.
  • Patients who are not receiving the best possible treatment for their heart failure, known as **suboptimal heart failure treatment**, cannot join the study.
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Investigated drugs

  • Sodium Zirconium Cyclosilicate (SZC)

    is being studied for its ability to help manage heart failure in patients with reduced ejection fraction. It works by controlling the levels of potassium in the blood, which can be important for patients taking certain heart medications. The goal is to see if it can safely and effectively optimize the use of other heart failure treatments.

  • Aldosterone Receptor Antagonists

    are medications used to treat heart failure by blocking the effects of aldosterone, a hormone that can cause the body to retain salt and water. This helps reduce the strain on the heart and improve symptoms in patients with heart failure. The trial is exploring how these medications can be optimized with the help of Sodium Zirconium Cyclosilicate.

What is already known about the treatment

Sodium Zirconium Cyclosilicate – This medication is administered orally and is used to treat high levels of potassium in the blood, known as hyperkalemia. It is currently being studied in clinical trials for its effectiveness in optimizing heart failure treatment, particularly in patients with reduced ejection fraction. Sodium Zirconium Cyclosilicate works by exchanging sodium ions for potassium ions in the intestines, thereby reducing potassium levels in the body. It is classified as a potassium binder and is being explored for its potential to improve heart failure management.

Investigated diseases

  • High-risk hyperkalemia

    This condition involves elevated levels of potassium in the blood, which can affect heart and muscle function. It often occurs in individuals with kidney problems or those taking certain medications. As potassium levels rise, symptoms may include muscle weakness, fatigue, and irregular heartbeats. If not managed, it can lead to more severe complications affecting the heart and muscles. Monitoring and managing potassium levels are crucial to prevent progression.

  • Heart failure

    This chronic condition occurs when the heart is unable to pump blood effectively, leading to symptoms like shortness of breath, fatigue, and fluid retention. It can result from various underlying heart conditions, such as coronary artery disease or high blood pressure. Over time, the heart's ability to function may decline, causing worsening symptoms. Patients may experience difficulty in performing daily activities due to reduced blood flow. The condition requires ongoing management to maintain quality of life.

  • Suboptimal heart failure treatment

    This term refers to the inadequate management of heart failure, where treatment does not fully control symptoms or prevent disease progression. It may result from incorrect medication dosages, poor adherence to treatment plans, or lack of access to appropriate therapies. Patients may continue to experience symptoms like fatigue and fluid retention. Over time, inadequate treatment can lead to worsening heart function and increased hospitalizations. Addressing suboptimal treatment is essential for improving patient outcomes.

Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2024-511502-24-02Protocol codeESR-19-20262Estimated enrolment1 patientSponsorVaestra Goetalandsregionen

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On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).