A Behavioural Weight Loss Intervention Delivered in Cardiac Rehabilitation for Patients With Atrial Fibrillation and Obesity: The BeWEL IN CR-AF Study

One-in-four Canadians will be diagnosed with an abnormal heart rhythm called atrial fibrillation (AF) in their lifetime. This is expected to double by 2050, owing to an aging population and increased age- and health behaviour-associated AF risk factors (e.g., poor cardiorespiratory fitness, Type II diabetes, hypertension, and obesity). AF is associated with an increased risk of severe health outcomes including stroke, heart failure, dementia, and death. Nearly three-quarters of people with AF also have obesity (excess body weight). According to research, people with obesity that lose approximately 10% of their body weight can experience relief from uncomfortable AF symptoms. Losing weight may even help people return to a normal heart rhythm. Cardiac rehabilitation (CR) is a proven way to help people with heart disease live longer, healthier lives. So far, research has not shown whether CR helps improve the abnormal heart rhythms seen in AF. This may be because CR programs usually do not offer specific help with weight management. Therefore, adding behavioural weight-loss treatment (BWLT; group classes to change thoughts and behaviours to encourage weight loss) to CR programs may help people with AF and obesity experience relief from their symptoms. This randomized controlled trial will assess whether the combination of an AF-specific 'small changes' BWLT and traditional CR results in a greater proportion of patients with AF and obesity achieving ≥ 10% body weight loss compared to patients who receive standard care (traditional CR alone). Traditional CR consists of participating in exercise sessions, supervised by health professionals, twice per week for 12 weeks. In addition to traditional CR, patients that are randomized to receive BWLT will attend 12 weekly online group therapy classes to learn strategies from psychology to help encourage weight loss. The investigators will collect data pertaining to weight, AF burden, physical activity, and disease-specific and generic patient-reported outcomes. This information will determine if taking CR+BWLT helps patients with weight loss and AF symptoms. Further, it will help efforts to provide effective treatment to patients with AF to help participants lose weight and reduce or eliminate AF symptoms.