Catheter ablation as first-line treatment in patients with atrial fibrillation: a Bayesian network meta-analysis
Authors: Bonanno C , Borio G L , Paccanaro M , Rossillo A , Vittadello S , Varotto L , Caprioglio F 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Clinical trials suggest that early catheter ablation (CA) can be superior to anti-arrhythmic drugs (AADs) in "naïve" patients with AF. A low power to examine the outcomes, the use of a single technology ablation, and the short follow-up period are significant limitations of the studies. The EARLY-AF (Early Aggressive Invasive Intervention for Atrial Fibrillation) trial recently reported the results over three years of follow-up. Our research aims to update the comparison among different CA technologies with AADs as reference treatment. Interest outcomes included freedom from atrial tachycardia recurrences (ATRs) for efficacy and serious adverse events (AEs) for safety.

Methods
A systematic literature search was carried out up to Oct 31, 2022. We considered studies of patients with untreated atrial fibrillation who were enrolled in a trial in which they had been assigned to undergo initial rhythm-control therapy with cryoballoon (CRYO) or radiofrequency (RF) CA in at least one arm or to receive antiarrhythmic drugs (AADs). A Bayesian random-effects network meta-analysis (NMA) model comparing ATRs and AEs among the treatment arms was performed using MetaInsight V 4.0.0 web-based tool. Estimates are presented as Odds Ratio (OR) with a 95% Credible Interval (CrI). The surface under the cumulative ranking area (SUCRA) probabilities was selected to calculate the ranking and hierarchy of the different treatments. The larger SUCRA indicates the greater likelihood of becoming the best intervention.

Results
Six randomised control trials (RCTs) and one observational study (OBS) with 1,418 patients (mainly paroxysmal AF) were included. The follow-up period ranged from 12 to 36 months. The NMA demonstrates that ATRs were significantly lower with CRYO (OR [95% CrI], 0.36 [0.17-0.72]) and RF (OR [95% CrI], 0.39 [0.16-0.72]) compared with AADs. No significant difference was observed between CRYO and RF (OR [95% CrI], 1.09 [0.39-2.4]). The higher SUCRA value for CRYO (79%) indicated the likelihood that the treatment is the best, followed by RF (70%) and AADs (8%) (Figure 1).
A total of 228 AEs were observed in 1,565 patients. The cumulative AEs associated with RF (OR [95% CrI], 1.31 [0.65-2.72]) and CRYO (OR [95% CrI], 0.72 [0.39-1.29]) were statistically similar in comparison with AADs. The indirect comparison showed no significant difference between the two ablative techniques. The probability of avoiding an AE was highest for CRYO (91%), followed by AADs (45%) and RF (14%) (Figure 2). In both analyses, the assessment of inconsistency for all studies was not significant (P &gt; 0.05).

Conclusions
Our NMA demonstrated a lower rate of ATRs in patients treated with CRYO or RF CA than AADs. Furthermore, CA had a safety profile comparable to AADs. These results suggest recommending CA as a first-line treatment when early rhythm control is warranted, mainly in patients with paroxysmal AF.