Atrial fibrillation (AF) is the most common cardiac arrhythmia and is strongly associated with obesity and excess body fat. Lifestyle interventions, including exercise and dietary modification, may reduce AF burden, but long-term randomized controlled trial evidence with objective AF burden assessment and advanced cardiac imaging is limited.

The MOVE-AF trial is a randomized controlled trial designed to evaluate whether a 12-month tailored exercise and dietary lifestyle intervention, compared with usual care, reduces atrial fibrillation burden and symptom severity and decreases cardiac and total body fat mass in overweight and obese adults with paroxysmal or persistent AF.

Obesity is a major modifiable risk factor for atrial fibrillation and contributes to AF pathophysiology through systemic inflammation, autonomic imbalance, and adverse cardiac remodeling, including increased epicardial and atrial fat. Although exercise and weight reduction have been shown to improve AF-related outcomes, robust long-term randomized evidence integrating exercise, dietary intervention, objective AF burden monitoring, and cardiac magnetic resonance imaging is lacking.

MOVE-AF is a parallel-group, open-label randomized controlled trial enrolling 158 overweight or obese adults with symptomatic paroxysmal or persistent AF. Participants will be randomized 1:1 to receive either a tailored exercise and dietary lifestyle intervention plus usual care or usual care alone. The intervention consists of individualized guideline-based aerobic and resistance exercise combined with dietary counseling aimed at reducing body fat mass.

Main outcomes include AF burden assessed using continuous ambulatory rhythm monitoring, AF symptom severity assessed using validated questionnaires, and cardiac and total body fat mass assessed by cardiac MRI and body composition analysis. Secondary outcomes include cardiorespiratory fitness, muscle strength, cardiac autonomic nervous system function, cardiac remodeling, healthcare utilization, cost-effectiveness, and genetic risk modification of intervention effects.

The study is conducted in accordance with the Declaration of Helsinki and applicable regulatory requirements. All participants will provide written informed consent before enrollment.

Inclusion Criteria:

• Age 18-75 years
• Body mass index (BMI) ≥27 kg/m²
• Documented atrial fibrillation (paroxysmal or persistent)
• Ability to participate in exercise training and follow study procedures
• Access to a smartphone or device enabling rhythm monitoring
• Provides written informed consent

Exclusion Criteria:

• Permanent atrial fibrillation
• Unstable angina pectoris or acute coronary syndrome within the past 3 months
• Participation in other lifestyle or drug weight reduction trials
• Significant left ventricular dysfunction (ejection fraction <30%)
• Severe valvular heart disease or planned cardiac surgery
• Severe heart failure (NYHA class IV) or severe angina (CCS class IV)
• Unstable coronary artery disease or recent myocardial infarction
• Severe pulmonary disease limiting exercise capacity
• Active malignancy
• Autoimmune or systemic inflammatory diseases
• Severe renal or hepatic failure
• Memory disease or significant cognitive impairment
• Unstable psychiatric condition
• Recent joint or back surgery within the past 6 months
• Continuing back or joint pain symptoms and inability to take part in individualized exercise training
• Contraindications to exercise testing or training, including cardiac symptoms or cardiovascular symptoms, making exercise unsafe
• Pregnancy or breastfeeding
• Participation in another interventional study
• Any condition judged by investigators to make participation unsafe or infeasible