The established and the challenger: A direct comparison of current cryoballoon technologies for pulmonary vein isolation

Abstract

Introduction: Cryoballoon (CB) ablation for pulmonary vein isolation (PVI) is an effective treatment of atrial fibrillation (AF). Recently, a novel cryoablation system was introduced. The aim of the study was to compare the safety, efficacy and biophysical characteristics of a novel cryoablation system (POLARx™; Boston Scientific) to a commonly used and clinically well characterized system (Arctic Front Advance Pro™, AFA; Medtronic). Methods and Results: Fifty consecutive patients with symptomatic AF, who underwent CB-based ablation with the POLARx were compared to 50 consecutive patients treated with the AFA. Acute PVI was achieved in 99.8% (POLARx 99.5%, AFA 100%, p = 1.00). Time to isolation (TTI) was comparable in both groups (POLARx 35 [27, 48] s, AFA 30 [21, 43] s, p = 0.165). The POLARx showed a lower balloon temperature at TTI (POLARx −44 [−50, −36] °C, AFA −31 [−38, −21] °C, p < 0.001) and lower nadir temperature (POLARx −60 [−65, −55] °C, AFA −48 [−54, −45] °C, p < 0.001). Procedure time (POLARx 80 [60, 105] min, AFA 62 [42, 80] min, p < 0.001), fluoroscopy time (POLARx 17 [13, 22] min, AFA 11 [7, 16] min, p < 0.001) and freeze cycles per patient (POLARx 5 [4, 6], AFA 4.5 [4, 5], p = 0.002) were higher in the POLARx group. Two cerebral ischemic events occurred in the POLARx group, two patients in each group had phrenic nerve injury. Conclusion: Both systems enable effective isolation of pulmonary veins. The POLARx required longer procedure and fluoroscopy times. Larger, prospective and randomized studies are needed to assess long-term efficacy and safety of this technology.

Comparison of the acute outcome of two cryoballoon technologies for pulmonary vein isolation: An updated systematic review and meta-analysis

“…Heterogeneity for the outcome of first freeze isolation LIPV was driven primarily by the study of Guckel et al [13] After the exclusion of this study, no difference between was detected in the likelihood of first freeze isolation LIPV (P = 0.16) (Supplemental figure S5 A). Heterogeneity for the outcomes of TTI recording LSPV, TTI LSPV and TTI RSPV was driven primarily by the study of Moser et al [16] After the exclusion of this study, TTI recording LSPV and TTI LSPV became in favour of POLARx (P = 0.004 and P = 0.02, respectively) (Supplemental figure S5 B and S5C). Furthermore, sensitivity analysis demonstrated that TTI RSPV became in favour of AFA-Pro after the exclusion of the study of Moser et al (P < 0.001) (Supplemental figure S5 D).…”

“…1 ). [8] , [9] , [10] , [11] , [13] , [14] , [15] , [16] All included studies were observational in design and found to be of good quality based on the Newcastle Ottawa scale (Supplemental table S1 ).

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“…Furthermore, sensitivity analysis demonstrated that TTI RSPV became in favour of AFA-Pro after the exclusion of the study of Moser et al (P < 0.001) (Supplemental figure S5 D). [16] No funnel plots were constructed to examine publication bias due to the low number of included studies (<10). The power of the test would be too low to distinguish chance from real asymmetry.…”

“… [11] Moser et al reported two patients with a periprocedural stroke with symptoms directly after the procedure. [16] Knecht et al report one patient with periprocedural stroke due to air embolism. [14] The air embolism in this patient caused an initial left-sided hemiparesis with progression to coma 6 h after the procedure.…”

“… [12] After this publication, other centers has published their experience with POLARx. [13] , [14] , [15] , [16] Therefore, we performed an updated systematic review and meta -analysis to confirm the robustness of the results of our previous meta -analysis. In addition, new outcome variables were evaluated such as time-to-isolation (TTI), likelihood of TTI recordings, minimal esophageal temperature, and thrombo-embolic events.…”