Comparison of very high-power short-duration and ablation index guided catheter ablation for cavotricuspid isthmus block.

BACKGROUND: Catheter ablation for the treatment of typical atrial flutter (AFL) provides effective and durable cavotricuspid isthmus (CTI) block associated with encouraging clinical outcome. Safety and efficacy of very high-power short-duration (vHPSD) temperature-controlled radiofrequency (RF) CTI ablation with 90 watts over 4 s (90 W/4 s) for typical AFL in comparison to conventional contact-force (CF) ablation-index (AI) guided ablation remains insufficiently investigated. METHODS: This single-center observational cohort study based on prospectively collected registry data included 100 consecutive patients undergoing CTI ablation for symptomatic typical AFL, with 50 patients treated using a vHPSD strategy (vHPSD-group) and 50 patients using an AI-guided ablation approach (AI-group). RESULTS: All CTIs were successfully blocked using either method. Median RF applications and RF times in the vHPSD-group and AI-group were 36 [IQR 26;47] versus 18 [IQR 12;26], p < 0.001 and 142 s [IQR 105;189 s] versus 574 s [IQR 401;983], p < 0.001, respectively. No differences in periprocedural complications were observed. Recurrence of AFL after 12 months was low with no significant differences between groups (2% vs. 2%, p = 1). In patients with re-ablation there was no difference in CTI block durability between both groups (75% vHPSD-group versus 67% AI-group, p = 0.809). CONCLUSIONS: Very HPSD ablation (90 W/4 s) is a safe and effective strategy for CTI ablation, offering the advantage of markedly shorter CTI RF application times compared with AI-guided ablation. Rates of periprocedural complications, acute and durable CTI block, and long-term arrhythmia recurrence are similar between the two approaches. We compared very high-power short-duration (vHPSD, 90 W/4 s) versus ablation-index-guided cavotricuspid isthmus (CTI) ablation in typical atrial flutter. Acute bidirectional CTI block was achieved in all patients. vHPSD significantly reduced CTI radiofrequency time without increased complications and showed similarly low recurrence and CTI block durability at 12 months.