Weight Loss Trial in Older Adults with Persistent Atrial Fibrillation

Key Takeaways

• The structured diet and behavioral program was associated with greater weight loss at 8 months than usual care.
• AF symptom severity was not significantly different between groups at the primary endpoint.
• No significant treatment effects were reported for physical performance, AF burden, cardiac imaging parameters, blood pressure, lipid profile, repeat cardioversion, or AF ablation, and no serious adverse events related to participation were reported.

In a UK trial, older adults with overweight and persistent atrial fibrillation assigned to an 8-month low-calorie diet and behavioral support program lost more weight than those receiving usual care, with an estimated between-group difference of -6.9 kg at 8 months.

This parallel-group, unblinded randomized clinical trial was conducted at 2 UK hospitals from November 14, 2018, to April 25, 2025. About 1,500 people undergoing electrical cardioversion for AF were assessed for eligibility, and about 500 adults aged 60 to 85 years with BMI 27 or greater and no exclusion criteria were invited. Of these, 119 provided informed consent and 118 were randomized, with 59 assigned to each group. Participants had a mean age of 68 years, and 33% were female. The intervention was an 8-month low-calorie diet and behavioral support program, and the comparator was usual care. The primary outcome was change in the AFSS symptom severity score at 8 months.

At 8 months, baseline-adjusted mean weight was 92.6 kg in the intervention group and 99.4 kg in the control group. That separation corresponded to weight reductions of 9.7% and 3.1%, respectively, with P < .001. AFSS symptom severity scores at 8 months were 7.9 and 8.9, with a between-group difference of -0.9 and a 95% CI from -3.3 to 1.4. The P value for symptom severity was .43, so the primary endpoint was not significantly different despite greater weight loss.

No significant treatment effects were reported for physical performance, AF burden, cardiac imaging parameters, blood pressure, lipid profile, repeat cardioversion, or AF ablation during follow-up. No serious adverse events related to trial participation were reported in either group. The randomized comparison showed substantial weight reduction without parallel improvement in AF symptom severity or the other measured outcomes during follow-up.