Comparison of pulmonary vein isolation between two commercially available cryoballoon systems

Abstract

BackgroundPulmonary vein isolation (PVI) using cryoballoon (CB) ablation has comparable efficacy and safety to the gold standard of radiofrequency ablation in the treatment of symptomatic atrial fibrillation (AF). Initial randomized control trials were performed using Arctic Front Advance Pro™ (AFr) (Medtronic, Dublin, Ireland) CB system. Novel CB systems have recently become available, including the POLARx™ (Px) (Boston Scientific, Marlborough, Massachusetts, USA) system. We aimed to compare PVI using the Px and the AFr CB systems in our patient population in terms of efficacy, safety and procedure characteristics in a routine clinical setting.MethodsWe performed a retrospective analysis of our internal AF ablation registry, containing 452 consecutive patients (pts) that underwent first procedure cryo-PVI for symptomatic AF. Primary endpoints were AF recurrence after 3 and 12 months, complication rate, procedure duration, fluoroscopy time and fluoroscopy dose. Secondary endpoints were minimal freeze temperature, time to isolation (TTI) and temperature at TTI for each of the pulmonary veins as well as minimal esophageal temperature during the procedure.ResultsThe primary efficacy endpoints of AF recurrence after 3 and 12 months were similar between the AFr and the Px systems (25.5% vs 21.3%, p = 0.416 and 22.2% vs 20.6%, p = 0.794, respectively). Complication rates were similar (3.9% vs 6.8%, p = 0.18) between groups and consisted mostly of mild vascular complications. The AFr group showed a significantly shorter procedural duration (68 (55–77) vs 73 (60–80) min, p = 0.002), and lower fluoroscopy dose compared to the Px system. Fluoroscopy times remained similar, however. Minimal freeze temperatures and temperatures at time of isolation were significantly lower in the Px group. However, the time to isolation and minimal procedural esophageal temperature were similar in both groups.ConclusionPVI using the AFr and the Px systems showed comparable safety and efficacy. Procedural times were longer for the Px system. The Px system showed lower freeze temperature measurements but seemed to have a comparable biological effect.