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Completed

NCT Number: NCT04625946

Metformin as an Adjunctive Therapy to Catheter Ablation in Atrial Fibrillation

This clinical trial is being done to determine if metformin, a drug which is normally used in diabetes, can reduce atrial fibrillation in patients who are having an ablation for atrial fibrillation (AF). Atrial fibrillation is an abnormal heart rhythm which research has shown is related in part to obesity and diabetes.

It is anticipated that the participants treated in the metformin arm will have greater freedom from recurrent atrial arrhythmias after ablation.

Eligible participants enrolled in the trial will be assigned to one of the treatment arms (no treatment or metformin) and have follow-up visits up to approximately 1 year after the ablation. Additionally, all patients will also receive education on lifestyle changes and exercise which are standard of care.

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Key information

Conditions

Atrial Fibrillation Arrhythmias, Cardiac Cardiovascular Diseases Heart Diseases Pathologic Processes Pathological Conditions, Signs and Symptoms

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

University of Michigan

Ann Arbor, Michigan, 48109, United States

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Body Mass Index (BMI) >25 kilograms / square meter (kg/m2) with plan for rhythm control of atrial fibrillation by catheter ablation
  • All subjects must be able to understand and willing to sign a written informed consent document.

Exclusion criteria

  • Individuals who are already taking metformin or other antidiabetic medications, including insulin
  • Known diabetes
  • Known allergy or Food and Drug Administration (FDA)-labeled contraindication to taking metformin (estimated glomerular filtration rate (eGFR)<30 millilitres per minute (mL/min)/1.73 square meters (m2), hypersensitivity to metformin, acute or chronic metabolic acidosis)
  • Patients taking carbonic anhydrase inhibitors
  • eGFR below 30 mL/min per 1.73 m2 or other clinical diagnosis of advanced renal disease
  • Acute or chronic metabolic acidosis (serum bicarbonate <22 milliequivalents per liter (mEq/L))
  • History of significant alcohol use (>2 drinks/day on average)
  • History of hepatic dysfunction (serum bilirubin 1.5 times greater than ULN)
  • History of New York Heart Association (NYHA) Class III or IV heart failure
  • Pregnancy or nursing

Treatment and study plan

metformin

Drug

Metformin immediate release will be initiated at 250 milligrams (mg) daily (orally), and increased as tolerated to 2000 mg daily over a four week period. If a patient is unable to tolerate a dose increase they will return to their last tolerated dose after omitting one days dosing. 0 to Six weeks after the initiation of drug the patient will undergo (standard of care) ablation with the intent of achieving rhythm control.

Participants will stay on the metformin 12 months after the ablation. In addition, all participants will receive education on lifestyle changes and exercise which are standard of care as well as have a discussion with their treating electrophysiologist and receive a handout.

Other names: Glucophage

Recommendations for lifestyle modification.

Behavioral

All subjects will receive education on lifestyle changes and exercise which are standard of care. This will include discussion with their treating electrophysiologist and a handout.

AliveCor

Device

Device will be used in order to record an electrocardiogram during symptoms perceived to be AF. All patients will be instructed to transmit at least once per week.

Primary outcomes

  1. Freedom from recurrent atrial arrhythmias by 12 months after a single ablation to eliminate AF

    Time frame: 12 months after ablation

    There will be a 3 month blanking period after ablation during which recurrent atrial arrhythmias will not contribute to the primary endpoint.

Secondary outcomes

  1. Time to recurrence of atrial fibrillation after a 3 month blanking period of ablation

    Time frame: up to 1 year after after ablation

  2. Freedom from recurrent atrial arrhythmias at 1 year after ablation after the blanking period of 3 months

    Time frame: 6 months after ablation

  3. Freedom from recurrent atrial arrhythmias at 6 months after repeat ablation

    Time frame: 6 months after a repeated ablation

  4. Atrial Fibrillation Severity Score (AFSS)

    Time frame: up to 12 months after ablation

    There are a total of 19 questions (parts A,B, and C) in this questionnaire. This collects information regarding the participants atrial fibrillation. It includes seven questions for subjects to report severity of symptoms (i.e. palpitations, shortness of breath at rest/physical activity, exercise intolerance, fatigue at rest, and lightheadedness/dizziness, chest pain or pressure) on a Likert scale from 0 (subject did not have this symptom) to 5 (symptom bothers subject a great deal).

  5. Percent change in weight at 3 months after ablation

    Time frame: 3 months after ablation

  6. Percent change in weight at 6 months after ablation

    Time frame: 6 months after ablation

  7. Percent change in hemoglobin A1c at 6 months after ablation

    Time frame: 6 months after ablation

  8. Percent change in hemoglobin A1C at 12 months after ablation

    Time frame: 12 months after ablation

  9. Incidence of major procedural complications

    Time frame: up to 30 days

    Complications include but are not limited to major bleeding, vascular injury, myocardial perforation, stroke, and mortality.

  10. Atrial Fibrillation related morbidity during follow-up

    Time frame: up to approximately 1 year after ablation

    During follow-up visits information will be collected regarding Emergency department visits and hospital admissions due to AF, Transient Ischemic Attack (TIA)/cerebrovascular accident (CVA), and mortality. These will be collected as total numbers between groups.

  11. Burden of Atrial Fibrillation assessed by AliveCOR Kardia Devices

    Time frame: 6 months after ablation

  12. Burden of Atrial Fibrillation assessed by AliveCOR Kardia Devices

    Time frame: 1 year after ablation

  13. Burden of Atrial Fibrillation assessed by AliveCOR Kardia Devices

    Time frame: 3 months after ablation

Sponsors and collaborators

Lead sponsor

University of Michigan

Other

Registry information

Important dates

Study start
2021
Primary completion
2025
Study completion
2025
First posted
Nov 12, 2020
Registry last updated
Sep 29, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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