Bariatric Surgery Reduces Risk of Subsequent Atrial Fibrillation

A retrospective study of 438 obese patients suggests that bariatric surgery can prevent a significant number of people from developing atrial fibrillation (AF).

A team of Mayo Clinic researchers led by Yong-Mei Cha, MD, compared data from 326 (74%) patients who underwent the procedure with that from 112 (26%) similar patients who served as the control.

At baseline, the surgery group did have a significantly higher mean body mass index (46.9 kg/m² compared to 43.2 kg/m² for the control group), but the incidence of atrial fibrillation was similar: 3.7% in the surgery group and 4.5% in the control group.

After a mean follow-up period of 7.2 years, the surgery group had, as expected, lost a significant amount of weight and improved on other metabolic tests. It also suffered far fewer cases of atrial fibrillation than the control group.

Indeed, new cases of atrial fibrillation occurred in 12.5% of the control group but just 3.1% of the surgery group.

The researchers noted several limitations in their study, including its retrospective nature and the fact that all the data came from patients at the same facility in Olmsted County, MN. Still, they concluded, the magnitude of the results boosts the argument for bariatric surgery in cases where patients are undecided.

“Obesity has become an epidemic in our culture and prevention efforts are more important now than ever,” said Cha, who presented the data at the recent meeting of the Heart Rhythm Society.

“Bariatric surgery is a preventative measure that obese patients may choose to take. Our study shows that the surgery helps them not only lose weight, but also reduces their risk of developing a serious cardiac condition, like atrial fibrillation.”

The results of the bariatric surgery study augment previous findings that bariatric surgery can improve heart health.

For example, a study of more than 1,100 patients published three years ago in The Journal of the American College of Cardiology compared the hearts of obese people who underwent the Roux-en-Y procedure with similar people who did not.

Surgery patients saw their enlarged left ventricles — a major risk factor for atrial fibrillation —shrink down toward normal size and their enlarged left atria stabilize. (Control patients saw no shrinkage in their left ventricles and continued growth in their left atria.)

Researchers also found improvements in the working of the left and right ventricles in surgery patients.

The new bariatric study also adds to the growing body of evidence that aggressive management of atrial fibrillation risk factors can greatly reduce the incidence of atrial fibrillation itself and the severity of cases that do develop.

At the same meeting of the Heart Rhythm Society, researchers from Australia presented a study on the effects of risk modification on atrial fibrillation patients who undergo catheter ablations.

That study found that an intense post-surgical program of medical treatment and behavior modification more than doubled the disease-free survival rate for initial ablations and boosted the chance of disease-free survival after multiple ablations from 48% to 87%.

Last fall, another team from Australia published a paper in the Journal of the American Medical Association concluding that simple weight management was associated with greatly reduced disease burden among obese people who already had atrial fibrillation.