Metformin may reduce Afib after ablation in adults with obesity

Taking the diabetes medication metformin may reduce episodes of atrial fibrillation, or Afib, in people with obesity, according to preliminary findings presented as late-breaking science at the 2025 American Heart Association Scientific Sessions.

Michigan Medicine researchers analyzed the effects of metformin on people with the irregular heart rhythm condition and obesity — but not type 2 diabetes — after they underwent an ablation procedure to correct faulty heart signals.

All participants received standard-of-care therapy, which includes lifestyle interventions and management of other health conditions, and half were prescribed metformin at random.

In the year after having an ablation procedure, participants on metformin had fewer overall Afib episodes.

Nearly three-quarters of them had no Afib episodes lasting 30 seconds or more, compared to just over half of those not on the medication.

A significantly smaller group of metformin users required a second ablation or a cardioversion, a procedure used to restore normal rhythm.

“We are seeing that people with atrial fibrillation and obesity, which is a common risk factor for Afib, may have a reduction in Afib episodes after ablation when adding metformin to standard-of-care treatment,” said Amrish Deshmukh, M.D., first author of study and clinical assistant professor of medicine at University of Michigan Medical School.

It’s estimated that atrial fibrillation affects up to 10.5 million Americans.

People with overweight and obesity are more likely to experience recurring Afib episodes after an ablation.

The Michigan Medicine study, called the Metformin as an Adjunctive Therapy to Catheter Ablation of Atrial Fibrillation, assessed 99 people who all received care at U-M Health.

Participants taking metformin didn’t experience significant changes in weight.

“Further studies are needed to evaluate how well other diabetes medications, such as GLP-1s, affect people with Afib and obesity but not type 2 diabetes,” said senior author Hakan Oral, M.D., chief of cardiovascular medicine at U-M Health and a director of the U-M Health Frankel Cardiovascular Center.

“None of these potential treatments would take the place of lifestyle interventions as standard-of-care for Afib treatment for these patients.”

Additional authors: Muazzum Shah, M.D., Paul Kozlowski, Kelly Arps, M.D. Michael Ghannam, M.D., Jackson J. Liang, D.O., Mohammed Saeed, M.D., Ryan Cunnane, M.D., Hamid Ghanbari, M.D., Rakesh Latchamsetty, M.D., Thomas Crawford, M.D., Krit Jongnarangsin, M.D., Frank Pelosi Jr., M.D., Frank Bogun, M.D., Aman Chugh, M.D., Fred Morady, M.D., and Elif Oral, M.D., all of University of Michigan.

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