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

Abstract

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.

News from the Cold Chamber: Clinical Experiences of POLARx versus Arctic Front Advance for Single-Shot Pulmonary Vein Isolation

“…No phrenic nerve palsy occurred in the POLARx group (0%) compared to two documented persistent phrenic nerve palsy events in the AFA group (<1%) (Table 6). These comparable and low phrenic nerve palsy rates are in line with other studies [15,17,[19][20][21]. Thus, further larger studies are certainly needed to elaborate potential benefits of the novel DMS.…”

“…In our study complication rates were very low (Table 6) with comparable results in the AFA and the POLARx group. This acts in concert with previous studies reporting initial experiences with the POLARx catheter under clinical conditions with low complication rates for CB-guided PVI [17,[19][20][21]23].…”

“…Meanwhile, a second CB-system (POLARx, Boston Scientific) became available. First clinical experiences with this novel system reported comparable efficacy and safety, but differences in terms of biophysiological parameters [14][15][16][17][18][19][20][21][22][23].…”

A tale of two balloons: technical and procedural difference between cryoballoon systems

“…Preliminary data shows the POLARx balloon reaches lower nadir temperatures than the Arctic Advance balloon [ 17 ]. The POLARx balloon also takes longer to thaw, which may reduce early re-ablation of PVI before concomitant tissues are sufficiently warmed and therefore reduce the incidence of dose-dependent complications such as esophageal injury.…”

“…The European IDE trial reported only one incidence of transient phrenic nerve palsy and no other major complications [ 18 ▪ ]. A review of the few European studies on the POLARx did not demonstrate significant incidents of PNP compared to the Arctic Front Advance [ 17 ], despite the addition of the DMS.…”