Nov. 18, 2025 – If you're among the 1 in 5 U.S. adults who have an abnormal heart rhythm problem called atrial fibrillation, there's been a flurry of new research about the condition that offers some guidance on your everyday choices and how those impact your risk of recurrence.
"The major risk is stroke, and preventing stroke is the name of the game with AFib," said cardiologist Eric Prystowsky, MD, director of the Cardiac Arrhythmia Service at Ascension St. Vincent Hospital in Indianapolis. He was not involved in any of the studies.
Three new studies shed light on some common questions: whether your morning coffee matters, whether a diabetes drug might help lower recurrence risk, and what new data reveals about AFib's link to dementia.
Here's what the latest research suggests:
- Coffee doesn't increase the risk of recurrent atrial fibrillation. A small but well-designed new study showed that people who drank a cup of coffee daily were not more likely than non-coffee drinkers to have a repeat atrial fibrillation episode after successful treatment with electrical cardioversion – a quick procedure where a doctor delivers a brief, controlled shock to the heart to put it back into a normal rhythm. People in the study agreed ahead of time to be randomly assigned to one of two groups: those who continued drinking coffee as they did before the study, and those who abstained for six months. The results were published this month in The Journal of the American Medical Association.
Why it matters: Many people – and even some doctors – still assume coffee triggers AFib, a long-held bit of "common wisdom" that isn't backed by strong evidence, Prystowsky said. It's a top concern for newly diagnosed patients, but experts say coffee is rarely a problem except in people with palpitations. The design of this latest study – randomizing people before asking them to keep drinking or abstain – makes the results particularly trustworthy, he said.
What you can do: If you're going to change one beverage you consume to manage atrial fibrillation risk, go ahead and keep drinking coffee and instead focus on reducing or cutting out alcohol, said Daniel M. Philbin, MD, director of the Cardiac Arrhythmia Service at Brown University Health in Providence, Rhode Island, who also wasn't involved in these studies. - Metformin helped reduce AFib recurrence in a small study of people with overweight and obesity. In a study of 99 people with overweight or obesity who had an ablation procedure – where doctors burn or freeze tiny areas of heart tissue to stop the abnormal signals that cause AFib – those who took the type 2 diabetes drug metformin after ablation were less likely to have recurrent AFib. None of the people in the study had diabetes, although 40% of them met prediabetic blood sugar criteria. The study was presented at an American Heart Association conference this month and hasn't been published in a peer-reviewed journal.
Why it matters: Doctors are talking about this study because it's another step toward understanding the connection between weight and AFib risk. An important previous study showed that people who lost 10% of their body weight were six times more likely to survive four years without recurrence. "It wasn't just weight loss, though," Prystowsky said, noting that those who lost weight had improved glucose and blood pressure levels.
Interestingly, in this latest metformin study, people saw AFib benefits without significant weight loss. That suggests the drug may be affecting the body in other ways – possibly through metabolism, inflammation, or fat around the heart – though researchers don't yet know the exact mechanism, Prystowsky said.
What you can do: "The most important takeaway from this small study is reinforcing the idea that the management of obesity makes a huge difference in outcomes for atrial fibrillation," Philbin said. He and Prystowsky agreed the study was too small for a doctor to recommend that a patient take metformin to reduce AFib risk, though. The study was "hypothesis-forming rather than game-changing, but it reinforces some ideas we know about atrial fibrillation that we know will work – you should exercise. You should lose weight. You should not drink alcohol," Philbin said.
He and his colleagues plan to explore whether AFib patients benefit from six weeks of supervised exercise and dietitian guidance the way heart attack survivors do. - Another study just linked AFib with dementia risk. Published this month in JACC: Advances, the analysis looked at 670,745 Medicare patients 65 and older and found that those who developed AFib after non-cardiac surgery were more likely to later be diagnosed with dementia. In cardiac surgery patients, dementia rates were similar regardless of AFib (about 4%). But after non-cardiac surgery, dementia was diagnosed in nearly 13% of people with AFib, versus 9% without – a 20% increased risk. Non-cardiac procedures ranged widely, with orthopedic (including joint replacements), gastrointestinal, and circulatory surgeries most common.
Why it matters: The study authors wrote it was "notable" that cardiac surgery patients who developed AFib weren't more likely to get dementia, suggesting their AFib may have been triggered by the surgery itself. They couldn't explain why non-cardiac surgery patients had a higher dementia risk and found no clear contributing factors like high blood pressure, diabetes, or prior stroke or heart failure. They hypothesized that undetected mild strokes or heart attacks – which can damage the brain and blood vessels – might play a role. The link between AFib and dementia is established, and while silent strokes and heart attacks are suspected contributors, the data shows a link rather than a cause. Prystowsky tells patients who get AFib after non-cardiac surgery that they have a higher risk of recurrence and need to be aware of it.
What you can do: If you're heading into surgery, worrying about AFib shouldn't be at the top of your list, Prystowsky said. But if you like to be prepared, both Philbin and Prystowsky advised that wearing a device like a smartwatch that can check your pulse and rhythm can help you spot any issues early. And if you've already had AFib after a non-cardiac surgery, regular monitoring is especially important – and you should call your doctor if your device flags an abnormal pulse or rhythm.
