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Study on the Effects of Bisoprolol Fumarate, Hydrochlorothiazide, and Metoprolol in Patients with Idiopathic Ventricular Fibrillation After Cardiac Arrest

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 patients who have experienced an unexplained cardiac arrest, a condition where the heart suddenly stops beating without a known cause. Specifically, the study looks at a type of cardiac arrest known as Idiopathic Ventricular Fibrillation (IVF). The purpose of the study is to investigate the effects of different beta-blocker treatments on these patients. Beta-blockers are medications that help manage heart conditions by slowing down the heart rate and reducing blood pressure.

The medications being studied include Bisoprolol Fumarate, Hydrochlorothiazide, Metoprolol, Atenolol, Chlortalidone, Nadolol, and Propranolol Hydrochloride. These medications are taken orally, meaning they are swallowed in pill form. The study will compare the effects of these medications to see which is most effective in preventing further heart issues in patients with IVF.

Participants in the study will receive one of these medications or a placebo for up to 36 months. Throughout the study, patients will have regular check-ups to monitor their heart health and any changes in their condition. The study will also assess the quality of life of participants after one year. The goal is to determine which treatment is most beneficial for patients who have survived an unexplained cardiac arrest.

The research process

The trial runs in 7 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, you will be identified as a survivor of an unexplained cardiac arrest, also known as idiopathic ventricular fibrillation (IVF).

    You must be 18 years or older to participate.

  2. Step 2

    Initial diagnostic work-up

    You will undergo a series of diagnostic tests to understand your heart condition better. These tests include an ECG (a test that records the electrical activity of your heart), a Holter monitor (a portable device that records your heart's activity for 24 hours), and an echocardiography (an ultrasound of your heart).

    Additional tests include taking blood samples during the first 24 hours, and either a coronary angiography or a cardiac CT-scan to check the blood vessels in your heart.

  3. Step 3

    Further evaluation

    Further evaluations will be conducted, including SAECG (a detailed ECG), stress-ECG (an ECG during physical activity), cardiac MRI (a detailed heart scan), and sodium-channel blocker testing (a test to see how your heart responds to certain medications).

  4. Step 4

    ICD implantation

    An ICD (implantable cardioverter-defibrillator) will be implanted. This device monitors your heart rhythm and can deliver shocks if necessary to correct irregular heartbeats.

  5. Step 5

    Medication administration

    You will be prescribed a beta-blocker medication. The options include bisoprolol fumarate, metoprolol, atenolol, or propranolol hydrochloride. These medications are taken orally.

    The specific dosage and frequency will be determined by your healthcare provider.

  6. Step 6

    Monitoring and follow-up

    Your condition will be monitored through the ICD data, focusing on any necessary therapies or shocks delivered by the device.

    The primary endpoint of the study is either the first appropriate therapy by the ICD, an aborted shock, or non-sustained ventricular fibrillation, or 3 years after you are discharged, whichever comes first.

  7. Step 7

    Quality of life assessment

    Your quality of life will be assessed after 1 year to evaluate the impact of the treatment and the study on your daily life.

Who can join the trial?

9 criteria

  • Must be a survivor of an unexplained cardiac arrest. This means the heart stopped suddenly, and doctors couldn't find a clear reason after doing many tests.
  • Must be aged 18 or older.
  • Must have undergone a series of tests after the cardiac arrest, including:
    • ECG: A test that checks the heart's electrical activity.
    • Holter monitor: A device worn during hospital stay to continuously record heart activity.
    • Echocardiography: An ultrasound test that looks at the heart's structure and function.
    • Blood samples taken during the first 24 hours.
    • Coronary angiography or cardiac CT-scan: Imaging tests to look at the heart's blood vessels.
    • Additional tests like SAECG (a detailed ECG), stress-ECG (heart activity during exercise), Cardiac MRI (detailed heart images), and Sodium-channel blocker testing (a test to see how the heart reacts to certain medications).
    • Must have an ICD implanted. An ICD is a device placed in the chest to help control irregular heartbeats.

Who cannot join the trial?

2 criteria

  • Patients who have had a **cardiac arrest** (heart suddenly stops beating) without a known cause, even after thorough medical tests.
  • Patients who have been diagnosed with **Idiopathic Ventricular Fibrillation (IVF)**, which is a type of irregular heartbeat with no known cause.
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Investigated drugs

Beta-blockers are a type of medication that helps manage heart conditions by slowing down the heart rate and reducing the force of the heart's contractions. This can help prevent abnormal heart rhythms and reduce the risk of sudden cardiac events. In this trial, beta-blockers are being studied to see how they affect patients with idiopathic ventricular fibrillation, a condition where the heart beats irregularly for no known reason.

What is already known about the treatment

Beta-blocker – This medication is typically administered orally in the form of tablets. It is currently being studied for its effects on patients who have experienced unexplained cardiac arrest, specifically those with idiopathic ventricular fibrillation (IVF). The main therapeutic use of beta-blockers in this context is to reduce the risk of further cardiac events by managing heart rhythm and preventing abnormal heartbeats. At the molecular level, beta-blockers work by blocking the effects of adrenaline on the heart, which helps to slow down the heart rate and reduce blood pressure. They are classified pharmacologically as beta-adrenergic blocking agents.

Investigated diseases

Idiopathic Ventricular Fibrillation (IVF) – Idiopathic Ventricular Fibrillation is a condition characterized by irregular and rapid heartbeats originating from the ventricles, the lower chambers of the heart, without a known cause. This arrhythmia can lead to a sudden loss of heart function, resulting in cardiac arrest. The progression of the disease involves episodes of ventricular fibrillation that may occur sporadically and unpredictably. These episodes can cause the heart to quiver instead of pumping blood effectively, leading to a sudden drop in blood pressure and loss of consciousness. Over time, repeated episodes can strain the heart and affect its overall function. The condition is considered rare and is diagnosed when other potential causes of ventricular fibrillation have been ruled out.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-518057-41-00Estimated enrolment218 patientsSponsorRegion Hovedstaden

sourced from the EU Clinical Trials Register and site verification

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