Obese people might be wise to slim down before undergoing an ablation procedure to treat an abnormal heart rhythm, researchers report.

Folks with atrial fibrillation who lost 3% or more of their body weight before undergoing ablation had greater odds of their heart returning to a normal rhythm than those who didn’t, a new study finds.

A-fib, as atrial fibrillation is called, is an abnormal heartbeat that causes the heart to beat faster and out of sequence. A-fib can cause blood clots that can result in a stroke.

To control a-fib, doctors prescribe medication or a procedure called catheter ablation. Ablation uses heat to kill heart cells that are causing the abnormality. The goal is to return the heart to its normal sinus rhythm.

“Weight loss is a key factor in the management of atrial fibrillation for those that are overweight or obese,” said lead researcher Dr. Jeffrey Goldberger, a professor of medicine and director of the Center for Atrial Fibrillation at the University of Miami School of Medicine.

Obesity is not only a risk factor for a-fib, but appears to also have an effect on treatment, he said.

“Obesity is known to be a pro-inflammatory condition,” he said. “It turns out that there’s fat tissue that sits directly on the heart muscle and these fat cells can secrete all sorts of hormones that could induce inflammation,” Goldberger said. “One of our hypotheses is that reduction in this fat tissue around the heart lowers inflammation and improves the outcomes.”

The findings were presented Friday at the annual meeting of the Heart Rhythm Society, in New Orleans. Findings presented at medical meetings are considered preliminary until published in a peer-reviewed journal.

For the study, Goldberger and his colleagues enrolled 65 obese patients with a-fib who were having ablation therapy. Patients were randomized to either receive the weight-loss drug Victoza (liraglutide) beforehand or standard protocol, Goldberger noted. Six patients withdrew, leaving 29 in the standard group and 30 in the weight-loss group.

Of the 30 patients who lost 3% to 10% of their body weight in the three months before the procedure, 88% remained in normal rhythm and off anti-arrhythmic drugs six months after ablation. That feat was achieved by just 61% of the 29 patients who lost less than 3% of their body weight, the researchers found.

After a year, 81% of the biggest losers were still in normal rhythm, compared with 42% of those who didn’t lose weight.

One cardiologist not involved with the study said inflammation is the likely focus.

“Inflammation can lead to coronary artery disease, and we think that inflammation also plays a role in atrial fibrillation,” said Dr. Laurence Epstein, system director of electrophysiology at Northwell Health’s Sandra Atlas Bass Heart Hospital in Manhasset, N.Y.

“When we get inside people’s hearts and record electrical activity in some people, we can see a fair amount of scarring when we don’t know why they would have any scarring, so clearly, there was some inflammation that occurred,” he said.

For ablation to be successful, it needs to alter what’s causing a-fib, Epstein said.

“In the short term, the ablation may be successful, but if you don’t modify what got them there in the first place, then the chances of having recurrent AF go up,” Epstein said. “That’s why I think losing weight has such an impact on the success rate of ablation.”

Losing weight is just one thing people can do to improve their health and make treatments, such as ablation, more effective, he said.

“Being healthy is healthy,” Epstein said. It is important that patients take an active role in their health. That includes things like losing weight, stopping smoking, dealing with addictions, not drinking alcohol and treating sleep apnea, he noted.

“It’s both challenging for patients but also empowering for patients because they have in their hands the ability to affect what their long-term outcomes are going to be, and they can take control of that,” Epstein said.

More information

For more on atrial fibrillation, see the American Heart Association.

SOURCES: Jeffrey Goldberger, MD, professor, medicine, and director, Center for Atrial Fibrillation, University of Miami Miller School of Medicine; Laurence Epstein, MD, system director, electrophysiology, Northwell Health’s Sandra Atlas Bass Heart Hospital, Manhasset, N.Y.; presentation, Heart Rhythm Society meeting, New Orleans, May 19, 2023