Results
A total of 70 patients were analyzed in this study, 20 from the POLARx™ group, enrolled from 12th August 2020 to 30th October 2020; and 50 from the Arctic Front Advance PRO™, sampled from a cohort of a previously published study (from October 2018 to February 2019). Their median age was 62.5 years, the majority were male (77.1%), had paroxysmal AF (94.3%), a median LA size of 32 ml/m², and CHA2DS2-VASc 1. Except for hypertension, the baseline clinical characteristics were similar between groups. All patients were undergoing their first PVI procedure. Details about baseline clinical characteristics can be seen in table 1 . The primary efficacy endpoint, acute success, was obtained in 100% of patients in both groups. No patients had necessity to undergo touch-up ablation with RF to complete vein isolation. Complications occurred exclusively in the Arctic Front Advance PRO™ group, but in a small number [0 vs. 4 (8%), p =0.39], among them, 3 self-limited phrenic palsies and a post-procedural pericardial effusion without necessity for intervention. Compared to Medtronic’s CB, POLARx™, in this cohort, was associated with a longer procedure (90 min vs. 60 min, p <0.001), lower minimum temperature (-57ºC vs. -47.5ºC, p <0.001), lower TTI temperature (-44ºC vs. -32ºC, p <0.001), but similar TTI (44.8 sec vs. 39 sec,p <0.001). The median number of veins isolated in the first attempt, per patient, was also lower in POLARx™ CB (3 vs. 4,p <0.001). Overall 27.1% of patients underwent a combined procedure, mostly cavotricuspid ablation line for typical atrial flutter (84.2% of the combined procedures). No difference in the hs-TnI level collected 24 hours after the procedure was observed between groups. The full procedural details are displayed in table 2 . They are also displayed as plot in figure 2 .