Comparison of procedural efficacy, balloon nadir temperature, and incidence of phrenic nerve palsy between two cryoballoon technologies for pulmonary vein isolation: A systematic review and meta-analysis.

INTRODUCTION: In May 2020, a novel cryoballoon system (POLARx; Boston Scientific) became available for catheter ablation of atrial fibrillation (AF). The design of the cryoballoon is comparable to the Arctic Front Advance Pro (AFA-Pro; Medtronic), but it is more compliant during freezing. We compared the procedural efficacy, biophysical parameters, and risk of phrenic nerve palsy (PNP) between the two cryoballoons. METHODS: Embase, MEDLINE, Web of Science, Cochrane, and Google Scholar databases were searched until June 1, 2021 for relevant studies comparing POLARx versus AFA-Pro in patients undergoing pulmonary vein isolation (PVI) for AF. RESULTS: A total of four studies, involving 310 patients were included. There was no difference between the two groups for outcomes regarding procedural efficacy: acute PVI (odds ratio [OR]: 0.43; 95% confidence interval [CI]: 0.06 to 3.03; p = .40), procedure time (mean difference [MD]: 8.15 min; 95% CI: -8.09 to 24.39; p = .33), fluoroscopy time (MD: 1.32 min; 95% CI: -1.61 to 4.25; p = .38) and ablation time (MD: 1.00 min; 95% CI: -0.20 to 2.20; p = .10). The balloon nadir temperature was lower for all individual pulmonary veins (PV) in POLARx compared with AFA-Pro (MD: -9.74°C, -9.98°C, -6.72°C, -7.76°C, for left superior PV, left inferior PV, right superior PV, and right inferior PV, respectively; all p < .001). The incidence of PNP was similar between groups (OR: 0.79; 95% CI: 0.22 to 2.85; p = .72). CONCLUSION: In AF patients undergoing PVI, POLARx and AFA-Pro had a similar procedural efficacy. Balloon nadir temperatures were lower with POLARx, however, the incidence of PNP was similar.