Background: Cryoballoon (CB)-based pulmonary vein isolation (PVI) is an established treatment option for symptomatic atrial fibrillation (AF). However, CB ablation is purely fluoroscopically guided and pulmonary vein (PV) occlusion assessment requires dye injection, causing exposure to ionizing radiation and potentially toxic dyes. The novel wide-band dielectric imaging system (KODEX-EPD) and its CB occlusion tool might enable for non-fluoroscopic guidance of CB-based PVI.

Aim:  The current study evaluated the impact of the KODEX-EPD system on CB-based PVI and the reliability of its occlusion tool to detect PV-occlusion when compared to standard-of-care fluoroscopic assessment.

Methods: Data from consecutive patients suffering from AF who underwent CB-based PVI in combination with the KODEX-EPD system were analyzed to determine the concordance of PV occlusion using dye-injections and the novel occlusion tool. A group of patients with AF, in whom conventional CB based ablation approach with PV-angiography was performed, acted as controls to compare procedural data.

Results: A total of 20 patients (group 1; 6 female (30%), 65±14 years, 15 paroxysmal (75%)) were ablated using the CB in combination with KODEX-EPD and compared to 20 patients (group 2; 6 female (30%), 66±10 years, 16 paroxysmal (78%)), who underwent conventional CB-based PVI.

Total procedure time was 69±10 vs 64±20 minutes (p=0.07), and left-atrial fluoroscopy time and dosage was 8±4 vs 9±3 minutes (p=0.38) and 304±171 vs 307±157 cGycm² (p=0.68).                                                               
For patients of group 1 LA mapping using the Achieve catheter (Medtronic Inc.) in combination with KODEX-EPD was obtained within 6±3 minutes. In a total of 80/80 PVs of group 1 (100%) PV occlusion could be analyzed for both imaging modalities. Total PV-occlusion verified by both, KODEX-EPD and angiography, was assessed in 64/80 (80%) PVs (right superior PV 16/20 (80%), right inferior PV 14/20 (70%), left superior PV 17/20 (85%), left inferior PV 17/20 (85%). 
All 80 PVs were successfully isolated. No periprocedural complication occurred.

Conclusion: The novel KODEX-EPD system and its occlusion tool allows for accurate PV occlusion assessment in the majority of PVs. Further studies are needed to determine whether the KODEX-EPD system reduces procedure time and/or the use of ionizing radiation.