Long-term sustained weight loss appears to be associated with significant reduction of atrial fibrillation (AF) burden with improved maintenance of sinus rhythm in obese patients, new data presented at the American College of Cardiology (ACC) Scientific Sessions 2015 indicate.
In addition, obese patients with AF who lost at least 10% of their body weight appear to be six times more likely to achieve long-term freedom from AF compared with those who did not lose weight.
Although previous studies have shown that weight loss can reduce the burden of AF, it was unknown if the effect was sustained, if there is a dose effect or if weight fluctuations mattered. This current study is the first to track the long-term effects of weight loss and the degree of weight fluctuation on AF burden.
Results suggest that patients who lost more weight and maintained a more stable weight over 4 years showed marked reductions in AF burden and severity — the study’s primary endpoints.
“Weight loss had a significant effect on AF symptom burden. There was a stepwise decline,” said lead study author Rajeev Pathak, MD, who is a cardiologist and electrophysiology fellow at the University of Adelaide in Australia. “Weight fluctuation does offset some of the benefits from weight loss. However, it is significantly better than people who had no weight loss.”
He said previous studies have shown that weight management can reduce AF symptoms in the short-term and improve outcomes of ablation. Dr. Pathak and his colleagues found that sustained weight loss was achievable in obese patients. Weight loss also led to favorable changes in cardiovascular (CV) risk factors such as high blood pressure (BP), obstructive sleep apnea and diabetes. Improvements were also found in the structure and function of the heart.
Researchers enrolled 355 participants in a dedicated weight loss clinic and tracked their health annually for an average of 4 years. All participants were obese and had AF at the start of the study.
To encourage weight loss, the clinic used a motivational, goal-directed approach that included three in-person visits per month, detailed dietary guidance and low-intensity exercise. The program also included support counseling and maintenance of a daily diet and physical activity diary.
Participants returned to the clinic annually for a health exam and AF monitoring. To assess the frequency, duration and severity of symptoms, patients completed questionnaires and wore a Holter monitor for 7 days. An echocardiogram was also conducted to assess measures of heart health including the volume of the left atrium and the thickness of the left ventricular wall.
After an average of 4 years, 45% of patients who lost 10% or more of their body weight and 22% of patients who lost 3% to 9% of their weight achieved freedom from AF symptoms without the use of any AF surgery or medication.
Additionally, the researchers found that only 13% of patients who lost less than 3% of their body weight were free of symptoms without these treatments. Even with the use of surgery or medication, those who lost more weight were substantially more likely to achieve freedom from AF symptoms.
Sustained weight management and a linear weight loss trajectory were also associated with greater freedom from AF. Patients who lost and then regained weight, causing a fluctuation of more than 5% between annual visits, were twice as likely to have recurrent rhythm problems as those who did not experience such fluctuations.
- Pathak R et al. Late-Breaking Clinical Trials: Long-Term Effect of Goal Directed Weight Management on an Atrial Fibrillation Cohort: A 5-Year Follow-Up Study (LEGACY Study). Presented at: American College of Cardiology 64th Annual Scientific Session & Expo; March 14-16, 2015; San Diego.