An 8-month low-calorie diet and behavioral support program may produce substantial weight loss but not improved atrial fibrillation severity or burden in older patients with persistent atrial fibrillation. Researchers also found no statistically significant differences in cardiac remodeling, quality of life, or the need for additional rhythm-control procedures between intervention and control groups.
In the LOSE-AF trial, the researchers enrolled 118 patients aged 60 to 85 years with persistent atrial fibrillation (AF) and a body mass index (BMI) of at least 27 who had been referred for electrical cardioversion at two UK hospitals. The patients were randomly assigned to receive either a structured low-calorie diet and behavioral support program delivered over 32 weeks or usual care consisting of a nurse consultation and written dietary guidance. The primary outcome was the change in the AF Severity Scale symptom severity score at 8 months. Secondary outcomes included AF burden measured with 14-day electrocardiographic monitoring, physical performance, body weight, quality of life, cardiac magnetic resonance imaging parameters, biomarkers, and rates of repeat cardioversion or AF ablation.
At baseline, mean age was 68 years, one-third of patients identified as female, and nearly half had long-standing persistent AF. Mean BMI was approximately 34 in both groups.
Patients assigned to the intervention lost 10% of body weight at 8 months compared with 3% in the control group. Baseline-adjusted mean body weight at follow-up was about 93 kg in the intervention group vs 99 kg in the control group. The researchers reported that the between-group weight difference persisted during long-term follow-up at a mean of 3.5 years.
Despite the greater weight reduction, AF symptom severity scores did not differ significantly between the groups at 8 months. Mean AF Severity Scale symptom severity scores were 7.9 in the intervention group and 8.9 in the control group. Symptom burden scores also were similar between the groups.
The researchers also found no statistically significant differences in AF burden. At follow-up, 42% of the patients in the intervention group and 49% in the control group were free of AF on monitoring. Rates of repeat cardioversion and AF ablation during long-term follow-up also did not differ significantly between the groups.
The intervention did not appear to worsen physical function or frailty-related measures. Physical Performance Test scores were unchanged between the groups, and no severe adverse events related to study participation were reported. Cardiac MRI also showed no statistically significant differences in atrial or ventricular structure and function between groups.
Prespecified subgroup analyses found no evidence that the treatment effects differed by age, sex, or baseline BMI. The researchers also observed no statistically significant differences in blood pressure, lipid levels, inflammatory biomarkers, or N-terminal pro–brain natriuretic peptide concentrations.
The researchers said the findings should be interpreted in the context of several study limitations. The trial was open-label, recruitment and follow-up were affected by the COVID-19 pandemic, and some secondary outcome assessments were incomplete. The intervention also produced moderate dietary weight loss rather than the larger reductions seen with pharmacologic therapy or bariatric surgery. In addition, nearly half of the enrolled patients had long-standing persistent AF, which the researchers said may reflect a population with more advanced atrial remodeling and treatment resistance.
“In older patients with overweight and persistent AF, a low-calorie diet and behavioral support program was associated with significant and sustained weight loss with no safety concerns but did not affect AF symptoms, AF burden, cardiac remodeling, or the need for further rhythm control interventions,” wrote lead study author Matteo Sclafani, MD, of the University of Oxford, and colleagues.
Full disclosures can be found in the study.
Source: JAMA
