3D imaging assistance impact on atrial fibrillation cryoablation efficiency, a method validation study

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: Other. Main funding source(s): CGRA: CARD; CGRB: 31’297 BACKGROUND: Pulmonary vein isolation (PVI) by cryoballoon ablation is a well-known therapy for the treatment of atrial fibrillation (AF). Current 3D-navigation technologies usually used with RF ablation allow for a drastic reduction of intra-procedural X-ray exposure and imaging aided/guided methods allow for better anatomical characterization improving acute and long-term procedural results. 3D imaging fusion on real-time fluoroscopy is a well-known technology but the incremental value of 3D imaging fusion as a guiding tool on AF cryoballoon ablation therapy has not been studied yet. PURPOSE: To increase procedural efficiency by integration of 3D imaging guidance in conventional cryoballoon PVI. METHODS: Using semi-automatic segmentation (Alphenix, Canon Medical Systems Corporation) obtained from pre-procedural cardiac computed tomography (CT); two anatomic volumes were fused on the real-time fluoroscopy display: left atrium (LA), including pulmonary veins (PV) and spine with proximal rib section (most radio-opaque body part in the thoracic area). The merging was performed by 3D registration of the bone segment with fluoroscopic acquisitions in three standard positions (AP, LAO, RAO), acquired at the beginning of the procedure. To standardize treatment workflow, the study was restricted to patients with paroxysmal atrial fibrillation. RESULTS: Twenty patients were included in the study: 10 in the control group (conventional fluoroscopy based cryoballoon ablation), and 10 in the 3D assisted group. Mean age was 59±15 SD years for the conventional group and 61.3±15.1 SD years for the 3D group with an 80% male population, in both groups. Acute PVI was achieved in all 20 patients. A decrease of both procedure time 86.8±16.1 SD in the control group Vs. 78.4±15.32 SD in the 3D group, and left sided dwelling time 69.7±14.31 SD in the control group Vs. 63.9±13.96 SD in the 3D group, although this trend did not reach statistical significance, while radiation time and cryo application time remained similar. CONCLUSIONS: 3D imaging integration is feasible and safe and allows for an exact PV anatomy depiction on fluoroscopy. The assistance workflow might help increase AF cryoablation efficiency and safety (lower left sided dwelling time). Further research is needed to evaluate the incremental value of 3D imaging to assist fluoroscopy-based cryoballoon ablation. This could also impact long-term results since 3D Imaging assistance could reduce the likeability of missing intermediate PVs during AF ablation procedures. [Figure: see text] [Figure: see text]