IntroductionRecently, a new cryoballoon (CB) technology (POLARx; Boston Scientific) has come onto the market. Preliminary data have shown that its acute safety and efficacy are similar to those of the first‐generation CB. The aim of this study was to assess the medium‐term outcome of pulmonary vein isolation (PVI) with the POLARxTM CB in a large multicenter registry.MethodsWe prospectively collected data on 125 consecutive patients with paroxysmal atrial fibrillation (AF) who underwent PVI by means of a novel CB system. Two cases of transient phrenic nerve palsy occurred, with full recovery in the 48h post procedure; no major procedure‐related adverse events were reported. During the 90‐day blanking period, 4 (3.2%) patients experienced an early recurrence. After the blanking period, over a mean follow‐up of 411 ± 62 days, 19 patients (15.2%) suffered an AF/atrial tachycardia (AT) recurrence. The 1‐year freedom from AF/AT recurrence was 86.4% (n = 17): 10 (8%) patients had an AF recurrence, 6 (4.8%) had an AT occurrence and 1 (0.8%) suffered both events. Patients with AF/AT recurrences had both a shorter deflation time and total deflation time. Moreover, CB ablations with measured TTI < 90 s and TTI < 60 s were more frequent in patients without AF/AT recurrence (88.5% and 77.4%, respectively) than in those who experienced at least one AF/AT recurrence (67.5% and 55.0%, p = .001 and p = .005, respectively).ConclusionThe novel POLARx cryo‐balloon system is safe and effective for PV isolation, displaying a 1‐year freedom from atrial arrhythmia recurrence of 86.4%, which is in line to that reported with AFA‐Pro CB or RF ablation.Clinical trial registrationCatheter Ablation of Arrhythmias with a High‐Density Mapping System in Real‐World Practice (CHARISMA). URL: http://clinicaltrials.gov/ Identifier: NCT03793998. Registration date: January 4, 2019.