Sustained weight loss in obese patients with atrial fibrillation (AF) reduces AF burden and symptom severity, the 5-year LEGACY* trial has shown. The benefits appeared to be dose dependent.

Patients who lost >10 percent of their body weight and kept it off for 4 years were six times more likely to achieve long-term freedom from arrhythmia without the help of medication or ablation compared with patients who lost less weight (p<0.001). Conversely, significant weight fluctuation over 4 years attenuated the positive impact of weight loss. Weight fluctuation of >5 percent was associated with a two-fold increased risk of arrhythmia recurrence (95% CI, 1.0-4.3; p=0.02). [J Am Coll Cardiol  2015;doi:10.1016/j.jacc.2015.03.002]

“LEGACY demonstrated that sustained weight loss is associated with dose dependent reduction in AF burden and maintenance of sinus rhythm,” said study author Dr. Rajeev Pathak, a cardiologist and electrophysiologist at the University of Adelaide in Adelaide, Australia. “Weight loss and avoidance of weight fluctuation are important strategies for reducing AF burden.”

The study enrolled 355 obese adults (body mass index ≥27 kg/m²) with AF, participating in a weight management program. Yearly weight trend and fluctuation were recorded.

After a median of 4 years, 135 patients lost >10 percent of their body weight, 103 patients lost 3-9 percent, and 117 lost ❤ percent. Arrhythmia-free survival rates were 86.2 percent, 66 percent and 40 percent, respectively.

“Weight loss also led to favourable changes in cardiovascular risk factors such as high blood pressure, obstructive sleep apnoea, and diabetes, along with improvements in the structure and function of the heart,” said Pathak.

Obesity and AF often co-exist. Weight loss in the short term reduces AF burden, but until this research, it is not known whether this benefit can be sustained in the long term, the authors said. LEGACY also addresses the impact of weight fluctuation and the role of weight loss clinics on arrhythmia control.

“A dedicated [weight loss] clinic improves patient engagement and promotes treatment adherence, thus preventing weight regain and fluctuation in AF patients.”