Analyzing the link between obesity and arrhythmia, LEGACY confirmed that among obese patients, weight loss greatly influenced freedom from atrial fibrillation, particularly among those who lost weight and maintained it. However, more than 5 percent fluctuation in weight over one year increased patient risks.

The findings of LEGACY (Long-Term Effect of Goal Directed Weight Management in an Atrial Fibrillation Cohort: A Long-term Follow-Up StudY) were presented March 16 at the American College of Cardiology (ACC) Scientific Sessions. Three separate weight-loss groups emerged out of the 355 participating patients: group one had a weight loss of 10 percent or more, group two had weight loss between 3 and 9 percent, while group three lost 3 percent or less of their initial body weight.

In the presentation at ACC, lead researcher Rajeev K. Pathak, MBBS, of Royal Adelaide Hospital in Australia, said that weight loss had a stepwise influence on arrhythmia-free survival. At its best, it was six times greater among those who achieved and maintained more than 10 percent weight-loss over one year. Similarly, they found a stepwise influence on weight loss and symptom burden, cholesterol levels, blood pressure control and glycemic control.

Weight loss also influenced cardiac structural remodeling and improved left atrium volume index, inter-ventricular septum thickness and left ventricular end-diastolic diameter among patients in groups one and two. Cardiac structure was unchanged or increased among patients whose weight loss was minimal.

However, weight fluctuation of more than 5 percent doubled the risk of recurrent arrhythmia. More than 5 percent weight fluctuation was also associated with an increased need for antihypertensive medication, higher mean fasting insulin, serum cholesterol and C-reactive protein. These patients also were susceptible to adverse cardiac structural remodeling, although left atrium volume index, intra-ventricular septum thickness and left ventricle end-diastolic diameter were largely unchanged.

Weight management clinics appeared to have a significant effect on weight loss and management, with 84 percent of patients in group one, 57 percent of patients in group two and 30 percent of patients in group three participating in one. Among those who maintained a greater than 10 percent weight loss, 85 percent attended a weight loss clinic.

However, the greatest influence on atrial fibrillation recurrence appeared to be group and history of diabetes.

Panelist Andrea Russo, MD, of the Cooper Heart Institute in Camden, N.J., commented that this research is “getting back to the basics” of the relationship between diet, weight and atrial fibrillation and provided “incredible data.”

“It’s also important to emphasize that there are years of epidemiologic evidence suggesting that obesity contributes in a major way to the epidemic of atrial fibrillation, but [Pathak and colleagues] took it a step further,” noted panelist Bernard Gersh, MD, ChB of the Mayo Clinic in Rochester, Minn.

The study was concurrently published in the Journal of the American College of Cardiology.