Safety and efficacy of a second-generation cryoballoon in the ablation of paroxysmal atrial fibrillation

Compared with the first-generation Arctic Front cryoballoon (ARC-CB), the new Arctic Front Advance cryoballoon (ARC-Adv-CB) increases the efficient CB-tissue contact surface during freezing, which may increase the incidence of phrenic nerve (PN) palsy (PNP).To evaluate the safety and efficacy of paroxysmal atrial fibrillation (AF) ablation with the ARC-Adv-CB as well as the merits of a predictor of PNP.AF ablation was performed by using a "single 28-mm big CB" approach. The rate of pulmonary vein (PV) isolation with a first cryoapplication was measured. The distance between the CB and a PN pacing catheter in the superior vena cava was measured to predict PNP during freezing.In 147 patients, PV were isolated with a single cryoapplication in 205 (81.3%) of 252 PV treated with the ARC-CB and in 280 (90.3%) of 310 PV treated with the ARC-Adv-CB (P = .003). The mean time to PV isolation was 52 ± 34 seconds and 40 ± 25 seconds (P < .001) and the temperature at the time of isolation was -36.1 ± 10.3°C and -32.3 ± 10.2°C (P = .001) in the ARC-CB and ARC-Adv-CB groups, respectively. Mean procedure and fluoroscopy durations were significantly shorter in the ARC-Adv-CB group. Transient PNP was observed in 7(10.6%) and 20(24.4%) of the patients treated with the ARC-CB and ARC-Adv-CB, respectively (P = .048). The distance between the lateral edge of the CB and a vertical line through the tip of the pacing catheter accurately predicted PNP (P < .001).The 28-mm ARC-Adv-CB enabled more efficient ablation of paroxysmal AF and shorter procedures than did the ARC-CB. This higher performance was associated with a higher incidence of PNP, which was predicted by the distance between the CB and the PN.