Efficacy of a Novel Ablation Index Algorithm for Cavotricuspid Isthmus Ablation Using a Flexible-Tip Ablation...

AutoMark Index (AI) is a novel ablation algorithm integrating contact force (CF), radiofrequency (RF) current, and application duration to provide real-time lesion formation feedback. Data of AI using a flexible-tip RF ablation catheter for cavotricuspid isthmus (CTI) ablation remain limited. The objective was to evaluate the efficacy and safety of AI-guided CTI ablation.

Consecutive 148 patients undergoing CTI ablation with a CF-sensing flexible-tip ablation catheter were included. Outcomes using an AI-guided protocol (50 W, targeting AI of 50; AI-50 group, 62 patients) were compared with a conventional protocol (40 W for 20 s; 40-W group, 86 patients).

The first-line success rate showed no difference between the two groups (40-W group: 72/86 [84.7%] vs. AI-50 group: 51/62 [82.2%], p = 0.81). The total RF application showed no difference (40-W group: 12 [9.5-15] vs. AI-50 group: 12 [9.7-16], p = 0.50); however, significant differences were observed in the total RF duration (40-W group: 274 [211-372] s vs. AI-50 group: 180 [138-249] s, p < 0.001), the RF duration for initial block (40-W group: 225 [163-323] s vs. AI-50 group: 149 [109-221] s, p < 0.001), and CTI procedural time (40-W group: 9.2 [6.0-14.6] min vs. AI-50 group: 6.3 [4.5-9.7] min, p = 0.007). No significant differences were observed in the mean CF, average temperature, and CTI length between the two groups. No major complications were observed in either of the groups.

AI-guided CTI ablation protocol is efficient in shortening RF duration for acute bidirectional CTI block and CTI procedure time compared to the conventional 40 W ablation protocol.