Efficacy and safety of pulmonary veins isolation by cryoablation for the treatment of paroxysmal and persistent atrial fibrillation.

AIMS: We examined the efficacy and safety of pulmonary vein (PV) isolation, using a cryoballoon catheter. METHODS AND
RESULTS: We studied 117 consecutive patients presenting with paroxysmal (n = 92) or persistent (n = 25) atrial fibrillation (AF), who underwent attempts at isolation of 442 PV with a cryoballoon catheter. They were followed in our ambulatory department for every 3 months, or earlier if they reported symptoms. A 48 h ambulatory electrocardiogram was recorded at the 3-month visit. We analysed the immediate and long-term procedural and clinical outcomes. We isolated 385 of 442 PV (87%) with a single cryoballoon application. In 19 patients (16%), an irrigated-tip radiofrequency (RF) catheter was used to create a supplemental focal lesion. A median of nine applications per procedure (range 6-12) was delivered. The mean, overall procedural duration was 155 ± 43 min (range 75-275), and mean duration of fluoroscopic exposure was 35 ± 15 min (range 12-73). At the end of the procedure, 103 patients (88%) were in sinus rhythm. Over a median period of 9.6 months (range 3-12), 11 patients were lost to follow-up. At 3, 6, 9, and 12 months of follow-up, respectively, 79, 79, 79, and 69% of patients presenting with paroxysmal AF had remained recurrence free, vs. 83, 73, 59, and 45% of patients, respectively, with persistent AF. Phrenic nerve palsy was the most frequent, although reversible complication.
CONCLUSIONS: Pulmonary vein isolation, using a cryoballoon catheter, was completed with a high rate of procedural and long-term success and low rate of minor complications. Supplemented, when needed, by focal RF, cryoballoon ablation was a safe and an effective alternative to a circumferential RF procedure.