Vol.:(0123456789) 1 3 Journal of Interventional Cardiac Electrophysiology https://doi.org/10.1007/s10840-022-01262-5 Comparison of the 1‑year clinical outcome of a novel cryoballoon to an established cryoballoon technology Sing‑Chien Yap 1  · Ante Anic 2  · Toni Breskovic 2  · Annika Haas 3  · Rohit E. Bhagwandien 1  · Zrinka Jurisic 2  · Tamas Szili‑Torok 1  · Armin Luik 3 Received: 7 May 2022 / Accepted: 27 May 2022 © The Author(s) 2022 1 Introduction Mid 2020, a novel cryoballoon was introduced, the POLARx (Boston Scientific, Marlborough, MA, USA). The design of this cryoballoon is comparable to Arctic Front (Medtronic, Minneapolis, MN, USA), except it has a lower balloon pres- sure during freezing making it more compliant. Previous studies have compared the procedural outcome of POLARx to Arctic Front Advance Pro (AFA-Pro) [1–5]. The aim of the present study was to compare the 1-year clinical out- come between POLARx and AFA-Pro of our original study cohort. 2 Methods We prospectively included consecutive patients who under- went cryoballoon ablation (CBA) for the treatment of AF between May and October 2020 in 3 centers. The periproce- dural management of our patients was described extensively previously [5]. A time-to-isolation (TTI)-based cryodosing was employed. The primary outcome was the freedom from atrial arrhythmias between 90 and 365 days after the pro- cedure. The primary outcome between both groups was compared using log-rank statistics. A P value of < 0.05 was considered statistically significant. 3 Results We enrolled 110 patients in the study period (POLARx: n = 57; AFA-Pro: n = 53). The POLARx group had less hypertension (31.6% vs. 58.5%, P = 0.007), had more use of direct acting oral anticoagulants (100% vs. 90.6%, P = 0.02), and used less antiarrhythmic drugs (52.6% vs. 75.5%, P = 0.02) in comparison to the AFA-Pro group. Most patients had paroxysmal AF (POLARx: 75.4% ver- sus AFA-Pro: 75.5%, P = 1.00). The rate of PV isola- tion was similar between groups (POLARx: 99.5% of all PVs versus AFA-Pro: 100% of all PVs, P = 1.00). The POLARx group had a longer procedure time (median 81 min versus 67 min, P < 0.001) and longer balloon in body time (median, 51 min versus 35 min, P < 0.001). There was no difference in the magnitude of PV occlusion (grade 4 occlusion: POLARx: 81.6% ver- sus AFA-Pro 77.3%, P = 0.21). Balloon nadir tempera- tures and temperatures at TTI were lower with POLARx (median − 55 °C versus − 47 °C, P < 0.001; − 46 °C ver- sus − 37 °C, P < 0.001), but the timing of TTI was simi- lar between groups (median 45 s versus 43 s, P = 0.44). In both groups, 2 patients had phrenic nerve palsy (PNP) at hospital discharge ( P = 1.00). During a follow-up of 1 year, there was no difference in freedom from atrial arrhythmias after a blanking period of 90 days (Fig. 1). The 1-year freedom from atrial arrhythmias was 82% and 87% for the POLARx and AFA-Pro group, respec- tively (log-rank P = 0.60). The rate of redo procedures in the first year was similar between groups (POLARx: 7% versus AFA-Pro: 0%, log-rank P = 0.12). Of the 4 patients in the POLARx group undergoing a redo proce- dure, all had at least one reconnected PV. The PV recon- nection rate was 33% (5 of 15 PVs). Of the 4 patients with PNP, all recovered. * Sing-Chien Yap s.c.yap@erasmusmc.nl 1 Department of Cardiology, Erasmus MC, University Medical Center Rotterdam, Dr. Molewaterplein 40, 3015 GD Rotterdam, the Netherlands 2 Department of Cardiology, Clinical Hospital Center Split, Split, Croatia 3 Medizinische Klinik IV, Städtisches Klinikum Karlsruhe, Academic Teaching Hospital of the University of Freiburg, Karlsruhe, Germany