Weight Reduction Intervention Significantly Reduces Symptoms of AF
Results of single-center, partially-blinded, randomized controlled trial show that weight reduction with intensive management of risk factors for atrial fibrillation (AF) reduce the symptoms and severity of AF and benefit cardiac remodeling [JAMA. 2013;310(9):2050-2060].
“Risk factor management needs to be the standard of care in any patient with AF,” said Prashanthan Sanders, MBBS, PhD, Center for Heart Rhythm Disorders, Department of Cardiology, Royal Adelaide Hospital, Adelaide, South Australia, an author of the study.
Along with aging, obesity is considered an important contributor to the growing prevalence of AF. Recent data show that obesity has a direct effect on atrial substrates. It is not known whether weight reduction and management of cardiometabolic risk factors can reduce the burden of AF.
To assess this, Dr. Sanders and colleagues randomized 150 patients with symptomatic paroxysmal or persistent AF to either a physician-led weight management program (n=75; intervention group) or self-directed general lifestyle measures (n=75; control group). Patients in the intervention group followed a 2-phase program that included induction of weight loss by very–low-calorie diet and low-intensity exercise in phase 1, followed by weight maintenance in phase 2 that included low-glycemic meals, more intensive exercise, and behavioral modification. Patients in the control group were provided with written and verbal nutrition and exercise advice at study enrollment.
All patients underwent intensive management of cardiometabolic risk factors, including hypertension, hyperlipidemia, glucose intolerance, sleep apnea, and alcohol and tobacco use.
All patients included in the study were between 21 and 75 years of age, had a body mass index of >27 kg/m2, and waist circumference >100 cm (men) or >90 cm (women). Patients who had participated in a weight loss program within 3 months of study enrollment were excluded from the study, along with patients with unstable international normalized ratio, diabetes treated with insulin, and significant cardiac valvular disease.
The primary outcome of the study was AF symptom burden, which was quantified using the Atrial Fibrillation Severity Scale (AFSS), a validated scale that encompasses 3 domains of AF: (1) event frequency (scored 1-10); (2) duration (scored 1.25-10); and (3) global episode severity (scored 1-10). The AFSS also assesses symptom severity, ranging from 0 (no symptoms) to 35 (severe symptoms).
At a median of 15 months follow-up, the study found that the patients who received the intervention had significantly greater reduction in weight compared to the control group (14.3 vs 3.6 kg; P<.001), as well as significantly reduced AF symptom burden scores (11.8 vs 2.6 points; P<.001), symptom severity scores (8.4 vs 1.7 points; P<.001), number of episodes (2.5 vs no change; P=.01), and cumulative duration (692 minute decline vs 419 minute increase; P=.002).
The results of this randomized trial show the difference between a physician-led program and standard care for reducing symptoms related to AF.
A limitation of the study, according to Dr. Sanders, is that it is a single-center study of a predominantly white population. “Now that we have shown that [the physician-led intervention] works, we need to find ways to extrapolate this to the general community and also determine the feasibility of doing this,” he said.
