AF ablation: evaluation of procedural parameters and acute results comparing ablation catheters with traditional and new irrigation design

Purpose: In order to make atrial fibrillation (AF) ablation procedures safer and easier, new technologies have been developed leading to optimize cooling of the electrode-tissue interface. Recently, two different companies proposed two novel irrigated ablation catheters. The first, a flexible and fully-irrigated tip catheter with an innovative design to better adapt the ablation tip to the surrounding tissue and the second with a greater number of irrigation holes being able to increase and optimize the irrigation process. We thought to investigate procedural parameters and acute results in pulmonary vein isolation (PVI) comparing four different ablation catheters: "traditional" irrigated catheters and new catheters with a new irrigation tip design providing a more efficient cooling. Methods and results: One hundred thirty-one patients with paroxysmal atrial fibrillation (PAF) were consecutively enrolled and underwent PVI being divided in four Groups: 32 patients treated with Thermocool (Th) catheter (Group 1), 34 with Thermocool SF (SF) catheter (Group 2), 32 with Coolpath (CP) catheter (Group 3) and 33 with Coolflex (CF) catheter (Group 4). All groups were comparable for population characteristics. PVI was obtained in 100% of patients in all groups. Among procedural parameters, procedural time was significantly shorter using SF and CF catheter in comparison to Th and CP catheters, respectively (SF, 114 min vs Th, 161 min; p=0.001; CF, 112 min vs CP, 139 min; p=0.008). Radiofrequency (RF) delivery time was significantly reduced with new technologies for both companies (SF 1977 sec vs Th 2683 sec; p<0.001; CF, 1694 sec vs CP, 1980 sec; p=0.039; Th vs CP p<0.001); nevertheless, there is no significant difference between SF and CF (p=0.095). Catheters with new irrigation design permitted a small but significant increment in RF power, particularly higher for SF (SF, 35 W vs Th, 32 W; p=0.035; CF, 32 W vs CP, 30 W; p=0.046; Th vs CP p=0.017; SF vs CF p<0.001). Concerning saline volume infusion, this was significantly reduced with new irrigated catheters (SF, 871 ml vs Th, 1610 ml; p<0.001; CF, 963 ml vs CP, 1231 ml; p=0.045) but no significant differences were observed between SF and CF (p=0.328). No acute or late complications occurred. Conclusion: PVI was obtained in all Groups without any complication. Catheters with new irrigation design have been able to reduce procedure and RF time. Furthermore, a more efficient cooling allowed to increase RF power delivery and to abate saline volume infusion.