Overweight patients with atrial fibrillation (AF) are more likely to experience a return of the heart rhythm disorder after a corrective procedure than those of normal weight, according to research presented at the 2022 European Heart Rhythm Association annual meeting (EHRA 2022, 3‒5 April, Copenhagen, Denmark).
“The risk of recurrent atrial fibrillation after ablation rose incrementally as body mass index (BMI) increased,” said lead author Jacob Toennesen (Gentofte University Hospital, Hellerup, Denmark). “Our study suggests that overweight patients should be advised to lose weight before the intervention to improve the likelihood of being free of the arrhythmia afterwards.”
AF is associated with elevated risks of stroke, heart failure and premature death, while more than 60% of patients have impaired quality of life. Toennesen said: “The potential for deleterious outcomes means that obtaining a normal heart rhythm is a crucial goal of treatment.”
While previous research has shown that obesity is associated with the development of AF, this study examined the link between BMI and a return of the heart rhythm disorder after ablation.
The study was conducted using Danish nationwide registries. It included a total of 9,229 adults who underwent a first-time AF from 2010 through 2018. Patients were divided into five groups according to BMI in kg/m2: underweight (below 18.5), normal weight (18.5 to 24), overweight (25 to 29), obese (30 to 34) and morbidly obese (over 34). The median age decreased from 64 years in the normal weight group to 60 years in the morbidly obese group.
Patients were deemed to have experienced AF during follow-up if they claimed prescriptions of anti-arrhythmic drugs, were hospitalised due to atrial fibrillation, underwent re-ablation, or had an electrical cardioversion which transmits electric shocks to the heart through electrodes on the chest to restore normal heart rhythm.
The authors analysed the relative risk of recurrent atrial fibrillation according to BMI after adjusting for sex, age, procedure year, heart failure, ischaemic heart disease, chronic obstructive pulmonary disease (COPD), chronic kidney disease, hypertension and diabetes. At one year, compared to the normal weight group, the overweight, obese and morbidly obese groups had a 19%, 22% and 32% higher likelihood of atrial fibrillation, respectively. The same pattern was observed after five years, with 15%, 18% and 26% higher risks of the abnormal heart rhythm in the overweight, obese and morbidly obese groups, respectively, compared with the normal weight group. The relative risk in underweight patients did not significantly differ from those with normal weight at either time point.
Toennesen said: “The study shows that recurrence rates of AF increased incrementally with rising BMI at short- and long-term follow-up. For instance, after one year 61% of normal weight patients were still free of the heart rhythm disorder compared to just 52% of morbidly obese patients. We also observed that both procedure duration and X-ray dose increased with rising BMI.”
He concluded: “The strength of association between high BMI and repeat AF after ablation was comparable to the influence of well-known factors like heart failure, COPD and hypertension which are typically treated in these patients. The findings indicate that aggressive weight management prior to ablation could potentially lead to better outcomes.”