Key Points:
- LOSE-AF is the first randomized trial to rigorously assess the effect of structured weight loss on AF symptoms in older adults with persistent atrial fibrillation (AF).
- Although participants in the intervention group achieved sustained and safe weight loss, there was no significant difference in AF symptom burden or recurrence compared with usual care.
- The findings challenge existing recommendations for weight loss in older patients with persistent AF and suggest that weight loss alone is insufficient to improve rhythm outcomes in this population.
Atrial fibrillation (AF) is a common cardiac arrhythmia that disproportionately affects older adults, increasing the risk of stroke, heart failure, and diminished quality of life. While weight loss is widely recommended as part of AF management—based largely on studies in younger populations—evidence supporting this approach in older individuals with persistent AF has been limited.
At the 2025 European Society of Cardiology (ESC) Congress in Madrid, researchers from the University of Oxford’s Radcliffe Department of Medicine and Oxford Population Health presented findings from LOSE-AF, a randomized controlled trial evaluating the effect of a structured weight-loss intervention in older adults with persistent AF. The trial enrolled 118 patients aged 60–85 years with overweight or obesity and persistent AF who had been referred for cardioversion. Participants were randomized to either an 8-month commercial low-calorie diet and behavioral support program or to usual care with written lifestyle advice.
By 8 months, the intervention group achieved an average weight loss of 10 kg (≈10% of baseline weight) compared to 3 kg in the control group. This difference remained evident 3.5 years later, confirming the durability and safety of the intervention. Importantly, no serious adverse events were associated with the weight-loss program, and there was no observed decline in physical performance.
Despite this, the intervention did not lead to improvements in AF symptoms, AF burden, or structural and functional measures of cardiac remodeling. Rates of AF recurrence and the need for repeat rhythm control procedures were similar between groups over the median 3.5-year follow-up.
“Our study demonstrates that weight loss in older adults with AF is achievable and safe, but it does not translate into meaningful improvements in arrhythmia burden or symptom relief,” said Dr. Matteo Sclafani, the study’s lead author. Dr. Rohan Wijesurendra, Senior Clinical Research Fellow at Oxford Population Health, added: “These findings suggest that while weight loss has general health benefits, additional therapies are needed to effectively manage AF in older adults.”
Funded by the NIHR Oxford Biomedical Research Centre and the British Heart Foundation, LOSE-AF (NCT03713775) provides critical evidence that may prompt reassessment of current AF management guidelines for older populations.
