Second Generation of Cryoballoons Can Improve Efficiency of Cryoablation for Atrial Fibrillation

BACKGROUND: We investigated whether the new second generation of cryoballoons can improve the efficiency and safety of cryoablation for atrial fibrillation (AF) during ablation and in terms of outcome. METHODS: Data of AF patients consecutively treated with a single 28-mm cryoballoon were analyzed. Patients were divided into two groups: the G1 group was treated with the first-generation cryoballoons (ArcticFront) and G2 with the second generation (ArcticFront Advance). Failure of cryoablation treatment was defined as detection of an episode of AF, atrial flutter, or atrial tachycardia lasting ≥ 30 seconds during 3-month follow-up. Left atrial diameter (LAD) was measured by transthoracic echocardiography before cryoablation. RESULTS: One hundred twenty-five patients (group G1/G2: 57/68) were enrolled. Mean total time of the whole procedure, cryomapping, and cryoablation was shorter with G2 than with G1 (P < 0.05). No complication occurred with G1 whereas with G2 the complication rate was 8.8%. During mean 12 ± 4 months follow-up, the overall success rate of cryoablation was 76.0% (95/125); it was higher with G2 (89.7% [61/68] vs 59.7% [34/57], P < 0.001). Patients in whom treatment failed had larger LAD (48 ± 8 mm vs 44 ± 6 mm, P = 0.002) than those in whom it succeeded. Type of cryoballoon (relative risk [RR] = 5.75 [2.16, 15.27], P < 0.0001) and LAD (RR = 0.90 [0.83, 0.97], P = 0.0043) were shown in multivariable analysis to be individually related to the difference in success rate. CONCLUSION: Ablation for AF with the new generation of cryoballoons is associated with higher success rate of pulmonary vein isolation and better outcome. However, more complications occurred during the early stage of application of the G2 cryoballoon.