In this randomized trial, cryoballoon ablation was noninferior to radiofrequency ablation with respect to efficacy for the treatment of patients with drug-refractory paroxysmal atrial fibrillation, and there was no significant difference between the two methods with regard to overall safety. (Funded by Medtronic; FIRE AND ICE ClinicalTrials.gov number, NCT01490814.).

Background-Paroxysmal atrial fibrillation (AF) naturally progresses toward chronic AF at an estimated rate of 15% to 30% over a 1-to 3-year period. Pulmonary vein (PV) isolation is increasingly performed for the treatment of drug-refractory paroxysmal AF. The long-term data on clinical outcome after circumferential PV isolation are limited. Methods and Results-From

AimsCryothermal energy (CTE) ablation via a balloon catheter (Arctic Front, Cryocath™) represents a novel technology for pulmonary vein isolation (PVI). However, balloon-based PVI approaches are associated with phrenic nerve palsy (PNP). We investigated whether ‘single big cryoballoon’-deployed CTE lesions can (i) achieve acute electrical PVI without left atrium (LA) imaging and (ii) avoid PNP in patients with paroxysmal atrial fibrillation (PAF).Methods and resultsAfter double transseptal punctures, one Lasso catheter and a big 28 mm cryoballoon catheter using a steerable sheath were inserted into the LA. PV angiography and ostial Lasso recordings from all PVs were obtained. Selective PV angiography was used to evaluate balloon to LA–PV junction contact. CTE ablation lasted 300 s, and the PN was paced during freezing at right-sided PVs. Twenty-seven patients (19 males, mean age: 56 ± 9 years, LA size: 42 ± 5 mm) with PAF (mean duration: 6.6 ± 5.7 years) were included. PVI was achieved in 97/99 PVs (98%). Median (Q1; Q3) procedural, balloon, and fluoroscopy times were 220 min (190; 245), 130 min (90; 170), and 50 min (42; 69), respectively. Three transient PNP occurred after distal PV ablations. No PV stenosis occurred. Total median (Q1; Q3) follow-up time was 271 days (147; 356), and 19 of 27 patients (70%) remained in sinus rhythm (3-month blanking period).ConclusionUsing the single big cryoballoon technique, almost all PVs (98%) could be electrically isolated without LA imaging and may reduce the incidence of PNP as long as distal ablation inside the septal PVs is avoided.

AimsThe primary safety and efficacy endpoints of the randomized FIRE AND ICE trial have recently demonstrated non-inferiority of cryoballoon vs. radiofrequency current (RFC) catheter ablation in patients with drug-refractory symptomatic paroxysmal atrial fibrillation (AF). The aim of the current study was to assess outcome parameters that are important for the daily clinical management of patients using key secondary analyses. Specifically, reinterventions, rehospitalizations, and quality-of-life were examined in this randomized trial of cryoballoon vs. RFC catheter ablation.Methods and resultsPatients (374 subjects in the cryoballoon group and 376 subjects in the RFC group) were evaluated in the modified intention-to-treat cohort. After the index ablation, log-rank testing over 1000 days of follow-up demonstrated that there were statistically significant differences in favour of cryoballoon ablation with respect to repeat ablations (11.8% cryoballoon vs. 17.6% RFC; P = 0.03), direct-current cardioversions (3.2% cryoballoon vs. 6.4% RFC; P = 0.04), all-cause rehospitalizations (32.6% cryoballoon vs. 41.5% RFC; P = 0.01), and cardiovascular rehospitalizations (23.8% cryoballoon vs. 35.9% RFC; P < 0.01). There were no statistical differences between groups in the quality-of-life surveys (both mental and physical) as measured by the Short Form-12 health survey and the EuroQol five-dimension questionnaire. There was an improvement in both mental and physical quality-of-life in all patients that began at 6 months after the index ablation and was maintained throughout the 30 months of follow-up.ConclusionPatients treated with cryoballoon as opposed to RFC ablation had significantly fewer repeat ablations, direct-current cardioversions, all-cause rehospitalizations, and cardiovascular rehospitalizations during follow-up. Both patient groups improved in quality-of-life scores after AF ablation.Clinical trial registrationClinicalTrials.gov identifier: NCT01490814.

Background-Pulmonary veins (PVs) can be completely isolated with continuous circular lesions (CCLs) around the ipsilateral PVs. However, electrophysiological findings have not been described in detail during ablation of persistent atrial fibrillation (AF). Methods and Results-Forty patients with symptomatic persistent AF underwent complete isolation of the right-sided and left-sided ipsilateral PVs guided by 3D mapping and double Lasso technique during AF. Irrigated ablation was initially performed in the right-sided CCLs and subsequently in the left-sided CCLs. After complete isolation of both lateral PVs, stable sinus rhythm was achieved after AF termination in 12 patients; AF persisted and required cardioversion in 18 patients. In the remaining 10 patients, AF changed to left macroreentrant atrial tachycardia in 6 and common-type atrial flutter in 4 patients. All atrial tachycardias were successfully terminated during the procedure. Atrial tachyarrhythmias recurred in 15 of 40 patients at a median of 4 days after the initial ablation. A repeat ablation was performed at a median of 35 days after the initial procedure in 14 patients. During the repeat study, recovered PV conduction was found in 13 patients and successfully abolished by focal ablation of the conduction gap of the previous CCLs. After a mean of 8Ϯ2 months of follow-up, 38 (95%) of the 40 patients were free of AF. Conclusions-In patients with persistent AF, CCLs can result in either AF termination or conversion to macroreentrant atrial tachycardia in 55% of the patients. In addition, recovered PV conduction after the initial procedure is a dominant finding in recurrent atrial tachyarrhythmias and can be successfully abolished. (Circulation. 2005;112:3038-3048.)