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

Background 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). Objective 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. Methods 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. Results 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). Conclusions 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.