Background: CartoXP and CartoMerge have been used to treat atrial fibrillation (AF) for several years. Our randomized prospective study compared clinical outcomes of these two versions of three dimensional electroanatomic mapping system in guiding catheter ablation for paroxysmal atrial fibrillation (PAF).
Methods: Eighty-one patients with symptomatic, drug refractory PAF were randomly assigned to CartoMerge group (n=42, mean age (54.5+/-13.1) years, history of AF=3.2 years) or CartoXP group (n=39, mean age (59.8+/-15.6) years, history of AF = 2.9 years). All patients underwent 64-slice computed tomography (MSCT) 1 to 3 days prior to ablation procedure. Using CartoMerge(TM) Image Integration Module, 3D anatomical images of the left atrium (LA) and pulmonary veins (PVs) derived from MSCT of CartoMerge group were established and merged with the electroanatomical map. The integrated images were used to guide the procedure of circumferential pulmonary vein isolation (CPVI). In the other group, CPVI was guided just by CartoXP. The endpoint of CPVI in both groups was abolition or dissociation of pulmonary vein potentials (PVPs).
Results: Mapping points to establish the electroanatomical model of the LA/PVs were 48.7+/-13.4 in CartoMerge group and 62.5+/-15.7 in CartoXP group (P<0.001). Mean distance between mapping points and the MSCT surfaces in CartoMerge group was (1.59+/-0.33) mm. Accomplishment of abolition or dissociation of PVPs was achieved 95.2% in CartoMerge group and 92.3% in CartoXP group. Durations of procedure and exposure to X-ray were (156+/-25) minutes, (179+/-21) minutes (P<0.001) and (19.6+/-7.5) minutes, (28.5+/-12.8) minutes (P<0.001), respectively. After a follow-up with duration of (11.9+/-3.1) months vs (12.4+/-3.6) months post the first ablation procedure, patients free of AF were 33 (78.6%) in CartoMerge group and 29 (74.4%) in CartoXP group (P>0.50). No patient suffered pulmonary vein stenosis, atrioesophageal fistula, stroke or death.
Conclusion: Compared to CartoXP, CartoMerge shortened the catheter ablation procedure and exposure to X-ray, without affecting the clinical outcomes of circumferential pulmonary vein isolation for the treatment of paroxysmal atrial fibrillation in experienced centres.