RESUMO
AIMS: To compare ablation lesion formation after pulmonary vein isolation (PVI) using the standard cryoballoon (CB-S) vs. the re-designed cryoballoon Arctic Front Advance (CB-A) using late gadolinium enhancement magnetic resonance imaging (LGE-MRI) 3 months post-ablation. METHODS AND RESULTS: Thirty-six consecutive patients with paroxysmal or short-lasting persistent atrial fibrillation (AF) were evaluated prospectively after PVI using the CB-S in the first 18 patients and the CB-A in the subsequent 18 patients. All patients underwent LGE-MRI and a 7-day Holter electrocardiogram monitoring 3 months after ablation. Fifty-six per cent of the patients were male (mean age 63.0 ± 9.1 years). Fifty-six per cent in the first group and 89% in the second group were free of AF recurrence 3 months after ablation (P = 0.025). Three months after ablation, LGE-MRI of the left atrium showed complete circular lesions in 35% of PVs in the first group and in 32% of PVs in the second group (n.s.). The left PVs showed a significantly higher proportion of PV segments with complete ablation lesions compared with the right PVs (83 vs. 34%; P < 0.001). CONCLUSION: Cardiac MRI is able to visualize induced ablation lesions after PVI and might be suitable to quantify ablation lesion amount. Ablation lesion formation did not differ significantly in patients treated with the CB-S vs. the CB-A, despite a significantly lower rate of AF recurrence after 3 months in the CB-A group. Left PVs showed a significantly higher amount of ablation lesions compared with the right PVs. Larger and randomized studies are needed to understand the relationship between representable tissue lesions and success rates.
