Retrospective review of Arctic Front Advance Cryoballoon Ablation: a multicenter examination of second-generation cryoballoon (RADICOOL trial)

Background: Pulmonary vein isolation (PVI) via catheter ablation is an approved therapy for patients with drug-refractory and symptomatic atrial fibrillation (AF). Furthermore, cryoballoon is now considered to be as effective as focal radiofrequency catheter ablation. This study examines the second-generation cryoballoon performance in a US multicenter review of real-world practices. Methods: By retrospective chart collections, the long-term efficacy and safety of the cryoballoon procedure were assessed in 15 US centers. All patients had a history of drug-refractory symptomatic paroxysmal AF and were treated with a cryoballoon PVI strategy at the index ablation. Results: Four hundred fifty-two patients were evaluated, and acute PVI was achieved in 99% of patients by cryoballoon catheter ablation. In 0.88% of patients (4/452), an additional focal ablation catheter was used to achieve acute PVI during the ablation procedure. Average procedure time was 128 (range 82 to 260) min, using an average of 17 (range 1 to 19) min of fluoroscopy. The most frequent adverse event was transient phrenic nerve injury (1.5%; 7/452 patients) which all resolved by the end of the procedure with no diaphragmatic dysfunction at discharge. There were no strokes, transient ischemic attacks, cardiac tamponade, atrioesophageal fistulas, or deaths during the study. At the 12-month efficacy endpoint, single-procedure success of freedom from atrial arrhythmia was 87% (393/452 patients). Conclusions: This real-world examination of the US practice demonstrates that second-generation cryoballoon ablation by PVI strategy is safe and effective among patients with paroxysmal AF.