Background: The high cooling power and ultra-low temperature cryoablation (ULTC) catheter called “Adagio” has been recently launched. A combination of a newly exploited cryogen and interchangeable stylet enables flexible and continuous lesion creation applicable not only for atrial fibrillation (AF) but also for other tachyarrhythmia by optimizing catheter shape. The exclusive esophageal warming balloon in order to preserve esophageal temperature is encouraged to prevent the potential risk of esophageal complication during procedure.

Aim: To assess the initial clinical data on pulmonary vein (PV) isolation for patients with AF using the novel ULTC catheter.

Methods: Consecutive patients who underwent AF ablation using ULTC in our center were enrolled. We assessed the acute procedural data focusing on procedural feasibility and safety comprising “first-pass isolation” defined as successful PV isolation after the initial application.

Results: A total of 16 AF patients (53 % male, age 67  years, 59 % paroxysmal AF) were analyzed. Sixty-six out of 67 PVs (98.5 %) were isolated with ULTC. The mean number of applications per PV was 2.3  1.1. Touch-up catheter was needed in one case at left inferior PV. The mean total procedure and fluoroscopy times were 79 ± 30 and 14 ± 7 mins, respectively. First-pass isolation was achieved in 34 PVs (50.7 %) varying across PVs from left superior PV (43.8 %) to right superior PV (58.8 %). In none of the patients an acute thromboembolic event (stroke or transient ischemic attack), a pericardial effusion/tamponade and postprocedural esophageal complication occurred. A single transient phrenic nerve weakening was observed at right superior PV.

Conclusion: Sequential PV isolation using the novel ULTC catheter was achieved feasibly without compromising safety. First-pass isolation was accomplished about in a half of PVs.