Effect of Weight Reduction and Cardiometabolic Risk Factor Management on Symptom Burden and Severity in Patients With Atrial Fibrillation
Editor’s Note: Commentary based on Abed HS, Wittert GA, Leong DP, et al. Effect of weight reduction and cardiometabolic risk factor management on symptom burden and severity in patients with atrial fibrillation: a randomized clinical trial. JAMA 2013;19:2050-60.
As the developed world becomes more developed, the burden of lifestyle-related diseases, such as obesity, high blood pressure and diabetes increases. These diseases associate strongly with atrial fibrillation (AF), so it is no surprise that rates of AF are also increasing—dramatically. AF, along with its less than satisfactory treatments, place great burden on both the patient and the health care system.
Can weight reduction and aggressive treatment of cardiometabolic risk factors reduce the burden and severity of symptoms of AF?
The study group included symptomatic obese patients with AF referred to a tertiary arrhythmia center in Adelaide, Australia. Enrolled patients had to have a body mass index (BMI) >27 and a waist circumference >100 cm (90 cm in women). Two groups of 75 patients were randomized to either a physician-led weight-loss group (intervention group) or a self-directed general lifestyle measures group (control.) Both groups had intensive management of risk factors, including aggressive control of blood sugar, lipids, blood pressure, sleep apnea, and alcohol/smoking cessation. Follow-up occurred every three months, up to a total of 15 months. The Atrial Fibrillation Severity Scale (AFSS) questionnaire was used to assess symptom severity and duration; seven-day holter recordings and echocardiography were done at baseline and 12 months. The primary endpoint was AF symptom burden and symptom severity.
The two groups were evenly matched and representative of a typical population of patients referred to an urban arrhythmia center for consideration of AFablation. Notably, females accounted for nearly half of each group.
There were six main findings: 1) BMI and waist circumference decreased in both groups, but the intervention group lost much more; 2) symptom burden and severity in the intervention group dropped significantly after three months and the curves continued to separate over time; 3) Holter recordings from the intervention group, taken at baseline and 12 months, revealed significantly fewer AF episodes (3.3 to 0.62) and shorter duration of episodes (1,176 min to 491 min); no significant changes were seen in the control group; 4) left atrial size and volume, posterior wall thickness, and myocardial mass all decreased significantly in the intervention group; 5) cardiometabolic risk factors improved in both groups, but there was a significant decrease in numbers of patients with high blood pressure, elevated lipids, and alcohol consumption greater than 30 g/week in the intervention group; 6) catheter ablation was performed in 14 patients in the control group compared with 10 in the intervention group.
Weight reduction with intensive risk factor management resulted in a reduction in AF symptom burden and severity and in beneficial cardiac remodeling. These findings support therapy directed at weight and risk factors in the management of AF.
This is a disruptive study because it changes an established way of thinking about AF treatment. To date, most of the care of patients with AF happens in the late stages of disease, and then, only to control symptoms and prevent complications. The missing factor of these strategies is that they do not address the root causes of AF: lifestyle factors and the resultant structural changes in the heart. This group has demonstrated that if motivated patients and caregivers target cardiometabolic risk factors, primarily with weight reduction, AF may be unnecessary. It is noteworthy indeed that only 10 of 75 patients on a waiting list for AF ablation received one. Although this was a small single-center study that used a physician-led intervention group, these findings are striking, biologically plausible, and consistent with previous work in animal models. Thus, it can be said that weight reduction and aggressive targeting of cardiometabolic risk factors should be a new standard of care in the treatment of patients with AF.
- Abed HS, Wittert GA, Leong DP, et al. Effect of weight reduction and cardiometabolic risk factor management on symptom burden and severity in patients with atrial fibrillation: a randomized clinical trial. JAMA 2013;19:2050-60.
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