Background

Radiofrequency ablation (RF) is the most commonly applied method for pulmonary vein isolation (PVI), in first as well as in re-do procedures. With the use of conventional RF catheters, lesion gaps leading to AF recurrence are still occurring frequently. Creation of transmural lesions takes a significant amount of time, making RF PVI a time-consuming procedure in daily clinical practice.

Objective

Currently, RF PVI is mostly done using saline irrigated ablation catheters in power-control mode, not being able to measure tissue temperature. The Diamondtemp RF ablation catheter (Medtronic plc, Dublin, Ireland) has recently been introduced and allows temperature-guided ablation using 6 thermocouples at the tip inbedded in material with high thermal diffusivity. The objective is to provide high ablation power levels with direct temperature feedback, ensuring application of safe transmural lesions.

Methods

We retrospectively analyzed procedural data from 80 consecutive patients who underwent de-novo PVI (62 patients) or repeat AF ablation (18 patients). AF ablation using the DT catheter was performed in 40 patients. Procedural data and long-term follow-up was compared with a matched control group, receiving AF ablation using a standard ablation catheter (ST group). 

Results

De-novo PVI was performed in 62 patients. DT-guided AF ablation resulted in shorter procedure duration (110.4 minutes vs. 144.5 minutes, p<0.02) and reduced applied RF energy (37097J vs. 87396J, p<0.02). In the DT group, less patients presented with arrhythmia recurrence compared to the ST group, without reaching statistical significance (5/28, 16.1% vs. 11/27, 35.5%; p=0.08). Eighteen patients underwent repeat AF ablation, evenly distributed between both groups. Among these patients, no significant differences could be observed in procedure duration (177.8 minutes vs. 180 minutes, p=0.90) and number of RF applications (105.1 vs. 122.1, p=0.57), with significantly less applied RF energy in the DT-group (68432J vs. 121132J, p=0.023). 

Conclusion

In this study, we demonstrate that an ablation strategy using the DT ablation catheter may lead to significantly lower procedure times for de-novo PVIs and less RF energy applied. Ablation using the DT system might be equally feasible in repeat AF ablation procedures, with less RF energy applied in our study. Intraprocedural complications were equally rare in our study population. Long-term follow up for de novo procedures shows no significant difference in arrhythmia recurrence in patients treated with the DT ablation catheter compared to the ST group.