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Study of Allopurinol to Reduce Cardiovascular Events in High-Risk Patients with Heart Disease and Long-COVID Syndrome

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What is this trial about?

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

This study focuses on people with high cardiovascular risk and very high cardiovascular risk, including those who have experienced long-COVID syndrome. The research examines conditions such as hyperuricemia (elevated blood uric acid levels), hypertension (high blood pressure), ischemic stroke, heart failure, peripheral arterial disease, atrial fibrillation (irregular heartbeat), and diabetes mellitus.

The study tests whether allopurinol, a medication that lowers uric acid levels in the blood, can help reduce the risk of cardiovascular events. Some participants will receive allopurinol tablets, while others will receive a placebo. The treatment will continue for approximately 5 years, during which participants will have regular check-ups to monitor their health status.

The main focus is to determine if allopurinol can prevent serious cardiovascular events such as heart problems, strokes, or the need for heart-related procedures. The study will also track other health changes, including heart function, blood vessel health, and the presence of long-COVID symptoms. Regular blood tests and heart examinations will be performed to monitor participants' health throughout the study period.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial visit and medication start

    You will receive either allopurinol tablets or a placebo (inactive tablet). Neither you nor your doctor will know which one you are taking.

    The study medication needs to be taken orally every day according to the prescribed schedule.

    Your blood uric acid level will be checked during this visit.

  2. Step 2

    Regular health monitoring

    Your health will be monitored through various tests including:

    - Heart examinations (echocardiogram - ultrasound of the heart)

    - Blood vessel examinations (ultrasound of neck arteries and abdominal aorta)

    - Blood tests to check kidney function, blood sugar levels, and liver function

    - Blood pressure measurements

    - Heart rhythm checks (electrocardiogram)

  3. Step 3

    Long-term follow-up

    The study will continue until May 30, 2028

    Regular check-ups will monitor for any heart or blood vessel related events

    Your doctor will track any COVID-19 related symptoms if they occur

  4. Step 4

    Safety monitoring

    Regular blood tests will check for medication effects on your body

    Any side effects will be recorded and monitored

    Your kidney function and liver health will be regularly assessed

  5. Step 5

    Study completion

    Final health assessments will be conducted

    All test results will be recorded

    Your participation will end after the final visit

Who can join the trial?

13 criteria

  • Age must be between 40 and 70 years old
  • Must provide written informed consent to participate in the study
  • Must have blood uric acid levels above 5mg/dl in tests from the last 6 months
  • Must meet at least one of these high cardiovascular risk conditions:
    • Have a calculated 10-year risk of death from heart disease of:
      • More than 2.5% if under 50 years old
      • More than or equal to 5% if 50 years or older
      • Have documented history of:
        • Stroke or mini-stroke
        • Heart failure (mild to moderate)
        • Poor blood flow to legs
        • Irregular heartbeat (at any time)
        • Have diabetes or high blood pressure with organ damage showing as:
          • Stiff blood vessels
          • Enlarged heart muscle
          • Increased protein in urine
          • Poor blood flow to ankles

Who cannot join the trial?

15 criteria

  • Current treatment with allopurinol or other medications that lower uric acid levels
  • Known allergy or sensitivity to allopurinol
  • Severe kidney disease (where kidney function is significantly impaired)
  • Severe liver disease that affects liver function
  • Active cancer or ongoing cancer treatment
  • Pregnancy or planning to become pregnant
  • Breastfeeding mothers
  • Participation in other clinical trials within the last 30 days
  • History of serious allergic reactions to medications
  • Inability to provide informed consent
  • Life expectancy less than 12 months due to any medical condition
  • Severe mental illness that could affect study participation
  • Alcohol or drug dependency
  • Recent major surgery (within last 3 months)
  • Unstable medical conditions that require frequent medication changes
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Investigated drugs

Allopurinol is a medication commonly used to lower uric acid levels in the blood. In this study, it is being investigated for its potential to reduce the risk of cardiovascular events (such as heart attacks and strokes) in patients who have a high or very high risk of cardiovascular problems, including those who have long-COVID syndrome. The medication works by blocking an enzyme that produces uric acid in the body, and researchers believe it may help protect the heart and blood vessels.

What is already known about the treatment

Allopurinol - A widely used oral medication that belongs to the class of xanthine oxidase inhibitors, primarily prescribed for treating hyperuricemia (elevated uric acid levels in blood) and preventing gout. The medication works by blocking an enzyme called xanthine oxidase, which is responsible for the production of uric acid in the body, thereby reducing uric acid levels and potentially lowering cardiovascular risks. Recent clinical trials are investigating its potential benefits in patients with high cardiovascular risk factors, including those with conditions like hypertension, heart failure, and diabetes mellitus, as well as in patients with Long-COVID syndrome, suggesting its possible protective effects on the cardiovascular system beyond its traditional use in gout management.

Investigated diseases

  • Hyperuricemia

    A condition where there is too much uric acid in the blood. The excess uric acid can form small crystals that deposit in various tissues of the body. The condition develops gradually and may remain asymptomatic for years.

  • Hypertension

    A chronic condition where blood pressure in the arteries is persistently elevated. It develops over many years and typically causes no symptoms in its early stages. The condition puts extra strain on blood vessels and vital organs.

  • Ischemic Stroke

    A condition where blood flow to part of the brain is blocked, causing brain tissue to become deprived of oxygen. It occurs when blood vessels supplying the brain become narrowed or blocked.

  • Intracerebral Hemorrhage

    A condition where blood suddenly bursts into brain tissue, creating both bleeding inside the brain and pressure on the brain. It's a type of stroke that occurs when blood vessels within the brain rupture.

  • Transient Ischemic Attack (TIA)

    A temporary period of symptoms similar to a stroke, occurring when blood flow to part of the brain is briefly interrupted. The symptoms typically resolve within 24 hours.

  • Heart Failure

    A chronic condition where the heart cannot pump blood effectively enough to meet the body's needs. The heart continues working but becomes less efficient over time.

Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-517610-15-00Protocol code2022/ABM/01/00027Estimated enrolment1 116 patientsSponsorAgencja Badań Medycznych

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