Meta-Analysis of Contemporary Atrial Fibrillation Ablation Strategies: Irrigated Radiofrequency Versus Duty-Cycled Phased Radiofrequency Versus Cryoballoon Ablation

Objectives: Using data from published studies, we performed a comparison of the 3 most commonly used atrial fibrillation (AF) ablation technologies in terms of efficacy and procedural duration.

Background: Catheter ablation is an effective treatment of atrial fibrillation (AF). Until recently, it has been performed with point-by-point delivery of irrigated radiofrequency energy (IRF). Phased duty-cycled radiofrequency (PRF) and cryoballoon ablation (CBA) have been introduced as alternatives to simplify AF ablation.

Methods: Electronic searches of 6 databases was performed, and eligible studies with IRF, PRF, or CBA as cohort arms were included. These ablation strategies were compared directly by using conventional frequentist meta-analysis and indirectly by using network meta-analysis, with outcomes graded using rank probability analysis.

Results: Direct conventional meta-analysis using all available published data showed that PRF was associated with an apparently higher freedom from AF than IRF (66.4% vs. 58%, respectively, p = 0.007), whereas CBA was comparable with IRF (64.8% vs. 62%, respectively, p = 0.99). PRF was associated with shorter procedural time (p < 0.0001), whereas there was a trend toward shorter procedural time with CBA than with IRF (p = 0.10). Indirect network meta-analysis using all available published data showed that PRF was associated with higher freedom from AF than CBA and IRF (odds ratio: 1.51; 95% confidence interval [CI]: 1.12 to 1.92) while having the shortest procedural time (weighted mean difference: 40.8 min; 95% CI: -63.31 to -18.11). Rank probability analysis also suggested that PRF was superior to CBA in terms of efficacy and procedural duration. However, when the meta-analysis was repeated using randomized controlled trial data alone, IRF and PRF were comparable in terms of freedom from AF (p = 0.35) over a mean follow-up of 9 months, but PRF was associated with significantly shorter procedural time (p = 0.006). There was a higher freedom from AF with IRF than with CBA (p = 0.04) over a mean follow-up of 12 months, whereas both techniques demonstrated similar procedural time (p = 0.47).

Conclusions: Although preliminary meta-analysis of pooled data suggested the highest efficacy with PRF, this was not replicated when analysis was limited to randomized data. Therefore, there was insufficient evidence to suggest that one ablation modality is more efficacious than another. However, there was a consistent reduction in procedural duration associated with PRF in all analyses. The present meta-analysis highlights the critical need for further randomized studies comparing available ablation technologies in terms of efficacy and safety.