Two Years Outcome after Ablation of Atrial Fibrillation with Cryo-Balloon 2^nd Generation; Efficacy, Safety, and Predictors for Recurrence

Aim: Consecutive patients with atrial fibrillation ablated with cryo-balloon second generation since May 2012 were included.

Methods: After a single trans-septal access and PV angiography PVI was performed using a 28-mm Cryo-Ballon. Mapping of PV signals before, during, and after each cryo application was performed with a 3F lasso catheter. The procedural endpoint after PVI was defined as complete elimination of all fragmented signals at the PV antrum with verification of entrance and exit block. The primary endpoint of this study was the first documented recurrence of atrial fibrillation (AF), atrial tachycardia, or atrial flutter (>30 sec.). All pts were followed prospectively with 7-day Holter ECG recordings every three months.

Results: The study group consisted of 538 pts with following characteristics: 323 (60.3%) male, paroxysmal AF (PAF) 383 (71.2%), median age (IQR)=60(53-66) y, LVEF 62 (59-62)%, history of AF 3.5(1.9-8.2) years, CHA2DS2-VASc-Score 1(1-2), left atrial area (LA area) 19.6 (17.4-22.5) cm². Follows complication were observed: tamponde one patient, stroke one patient, phrenic nerve injury (PNJ) was developed in 26 (4.8%) pts. After a median follow up of 16 (10-26) months, the primary endpoint was reached in 66/538 (12.3%) pts. There was no significant difference in clinical outcome between patients with PAF (343/383 (89.6%) pts free of recurrence) and persistent AF ((129/155 83.2% ), p=.08. Among all parameters analyzed only LA area was found to be predictive for outcome. The optimal cut-off point for LA area was defined at 21 cm². Among 331 pts with LA area < 21 cm² recurrences were noted in 23 (6.9%) vs. (43/207) (20.8 %) in pts with increased LA area ≥21 cm² (p<0.001),

Conclusions: PVI with CBA in patients with persistent AF seems to be as effective as in patients with PAF. LA area was revealed to be only one predictor of outcome after PVI with cryo-balloon. However, even in patients with enlarged left atrium success rate was very high in our cohort