Weight Loss in Elderly Patients with Atrial Fibrillation (LOSE-AF): A Randomised Controlled Trial

Atrial fibrillation (AF) affects over 1 million individuals in the UK and results in costs of over £450 million per year to the National Health Service (NHS). The incidence and prevalence of AF markedly increase with age, whilst obesity is the strongest modifiable risk factor for AF.

Preliminary data in relatively young patients suggest that Very Low Calorie Diet (VLCD) programmes induce significant weight loss (~14% body weight versus ~4% with general lifestyle advice), and lead to an impressive reduction in AF burden and AF-related symptoms, although the mechanisms underlying the latter effects remain unclear. Furthermore, the effectiveness of a VLCD intervention in the much more typical population of elderly overweight patients with AF, in whom weight-loss induced sarcopenia and increased frailty are potential concerns, is also unknown.

The BHF CRE award is for a pilot study to evaluate (a) adherence to the VLCD intervention in this specific patient population, (b) the degree and sustainability of weight loss achieved, and (c) the impact of weight loss on muscle mass and frailty measures. The findings will speak to the feasibility and safety of this approach, and inform power calculations for a full-scale multi-centre randomised controlled trial powered for efficacy (i.e. freedom from AF), for which we will seek external funding.