Efficacy and safety comparison between different types of novel design enhanced open-irrigated ablation catheters in creating cavo-tricuspid isthmus block

Abstract

Background: Clinical utility of irrigation-tip ablation catheters for cavo-tricuspid isthmus (CTI) ablation is established. Recently, new-generation enhanced-cooling irrigation-tip catheters were introduced into clinical use. This study compared the performance of different types of novel irrigation-tip catheters in CTI ablation.

Methods: One hundred patients undergoing CTI ablation with novel irrigated-tip catheters were included. Ablation was performed with a power output of 30-35W using either 4-mm flexible tip catheters [FlexAbility (FAs) St. Jude Medical, St. Paul, MN, USA] or 3.5-mm enhanced-cooling ring-tip catheters without [ThermoCool SurroundFlow (SFs), Biosense Webster, Diamond Bar, CA, USA] and with contact force sensing [ThermoCool SmartTouch SurroundFlow (STSFs), Biosense Webster] in 32, 34, and 34 patients, respectively.

Results: The successful CTI block creation rate was significantly higher for FAs than SFs/STSFs [32/32 (100%), 30/34 (88.2%), and 27/34 (79.4%), p=0.006]. In all 11 failed procedures, block was created by additional 5 (2-7) applications with 8-mm tip catheters. The radiofrequency (RF) application number (p=0.001) and energy (p=0.021) were significantly lower, and total RF time (p=0.005) and procedure time (p=0.036) significantly shorter in the FA than SF/STSF groups. The FA catheter was associated with significantly higher tip temperature readings (34.9°C vs. 32.0/33.0°C, p<0.001) and lower initial impedances than SF/STSF catheters (both p<0.001). The tip temperature reached the maximum temperature setting in 15/295 (5.1%) FA catheter applications among 11 (34.3%) patients, 0/521 (0%) ST applications, and 0/448 (0%) STSF applications. The mean RF power achieved during RF applications was significantly lower for FA than SF/STSF catheters (28.6W vs. 30.4/30.8W, p<0.001). Audible steam pops were detected in 1/448 applications in only the STSF group.

Conclusions: In human CTI ablation, flexible irrigation-tip catheters showed a significantly better performance than rigid enhanced-cooling irrigation-tip catheters.

Keywords: Atrial flutter; Catheter ablation; Cavo-tricuspid isthmus; Irrigation; Linear ablation.