Catheter Ablation for Atrial Fibrillation-Influence of Modifiable Risk Factors and Ablation Modality on Procedural Efficacy and Safety.

BACKGROUND: Modifiable lifestyle risk factors, in particular obesity and related conditions, are important drivers of atrial fibrillation (AF), impacting the severity of symptoms and influence the efficacy and safety of treatment.

OBJECTIVE: The study aimed to assess the impact of modifiable lifestyle factors on the effectiveness and safety of AF ablation, and examine the procedural characteristics, efficacy, safety and cost outcomes of cryoballoon vs radiofrequency ablation, in a real-world clinical setting.

METHOD: Patients undergoing catheter ablation for AF (June 2017 to December 2020) were included in this retrospective analysis. Efficacy and safety outcomes were obtained from electronic medical records and state-wide databases. The primary outcome was successful isolation of the pulmonary veins and freedom from AF without repeat ablation or ongoing antiarrhythmic therapy at 12 months.

RESULTS: The study included 141 patients (mean age 60±11 years, 57% male). The average body mass index (BMI) was 29.2±5.6 kg/m2 . Ablation by cryoballoon was undertaken in 59% (radiofrequency 41%). Acutely successful pulmonary vein isolation was achieved in 92%, however, only 52% (n=74) met the primary outcome (successful isolation of the pulmonary veins and freedom from AF without repeat ablation or ongoing antiarrhythmic therapy) at 12 months. Successful management of AF was more likely in patients with lower BMI (p=0.006; particularly with BMI <27 kg/m2 ; p=0.004) and weight (p=0.003), and in those without obstructive sleep apnoea (p=0.032). The only independent predictor of the primary outcome was BMI (β=0.25, p=0.004). Over 75% of complications occurred in those with BMI ≥27 kg/m2 .

CONCLUSIONS: Catheter ablation for AF is more likely to be unsuccessful in patients with uncontrolled risk factors, particularly obesity. Risk factor optimisation may improve procedural success and reduce the risk of procedural complications.