Accuracy and clinical outcomes of CT image integration with Carto-Sound compared to electro-anatomical mapping for atrial fibrillation ablation: A randomized controlled study

BACKGROUND: Carto-Sound integrates 2D intra-cardiac ultrasound imaging into a 3D environment to allow left atrial mapping from the right atrium without fluoroscopic assistance. We conducted an open randomized controlled study to compare procedural, clinical and accuracy parameters between CT integrated Carto-Sound and electro-anatomic mapping (EAM) for AF ablation. METHODS: Sixty index AF ablation patients were randomized equally to either the Carto-Sound or EAM mapping/navigation for their procedure performed at a single institution. Procedure and X-ray times, X-ray dose, navigational accuracy and clinical success were assessed. The study was powered to the primary outcome of fluoroscopy time. RESULTS: Total procedure (232 ± 60 vs 223 ± 48 min; p = 0.51), ablation (p = 0.84) and mapping times (p = 0.11) were similar in each group. In contrast, Carto-Sound reduced total X-ray time (65 ± 18 vs 51 ± 12 min; p = 0.001), via a reduction in both mapping (p<0.001) and remaining procedure X-ray time (p = 0.03). Left atrial access time (p = 0.03) was also reduced using Ultra-sound assisted 3D mapping compared to the EAM group. Carto-Sound maps demonstrated equivalent mean navigational accuracy (p>0.17) compared to EAM. Ultra-sound assisted 3D mapping did not improve single procedure drug free clinical success (EAM: 13/30 [43%] vs Carto-Sound: 15/30 [50%]) at a mean of 13 ± 5 months (p = 0.79). CONCLUSIONS: In the context of long left atrial procedures with high radiation doses, reduced X-ray and left atrial access times using CT integrated Carto-Sound mapping/navigation may have implications for patients and laboratory staff, albeit at an extra financial cost and the requirement of an additional access site for a right sided catheter. TRIAL REGISTRATION NUMBER: ACTRN12612000089831.