Background

The single procedure success rates of durable pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) varies between 80 and 90 %.

This prospective, randomized study investigated the efficacy of Cryo-Balloon PVI versus pulmonary vein isolation with RF-energy following the CLOSE protocol (ablation index (AI), interlesion distance £ 6 mm, surround flow catheter) in terms of single-procedure arrhythmia-free outcome, safety and procedural time. 

Methods and results

A total number of 150 patients undergoing de-novo catheter ablation for paroxysmal AF were randomized to two different treatment arms. In group-A patients, PVI was performed with the 23 or 28 mm Cryo-Balloon (Articfront Balloon in conjunction with an Achieve Mapping Catheter, Medtronic Inc). 

The ablation procedure in group B was performed with RF-energy, using AI and following the CLOSE protocol. PVI using AI incorporates stability, contact force (CF), time and power. The CLOSE protocol combines AI and ≤ 6 mm interlesion distance using a surround flow catheter (Biosense Webster Thermocool STSF). If AF persisted after PVI an electrical cardioversion was performed to obtain sinus rhythm (SR).

A total of 75 patients were randomized into each group without significant differences in baseline characteristics.

During a mean follow-up of 15 ± 6 months after a single procedure, 69 (92%) patients of group A were free of arrhythmia recurrence versus 68 (90.67%) patients in group B (p=ns). A total of 10 patients (group A: 4, group B: 6; p=ns) underwent a redo-procedure. No difference between both groups was observed in terms of patients with PV recovery (group A: 2 (2,67%) vs. group B: 3 (4%); p=ns). In 2 patients of group A and 3 patients of group B the PVs were durably isolated , whereas the patients had AF recurrence caused by extra-PV AF sources. Two patients of each group had continued paroxysmal AF but did not undergo redo-procedure.

With regard to the procedural data, the procedure time was significantly shorter in group A (115.35 ± 15.38 versus 70.53 ± 16.13; p<0.01), the flouroscopy time and dose area product showed no significant differences (Table 1). Both procedures were performed with a low number of complications, no pericardial effusion was seen in either group, in group A two patients had a significant hematoma of the groin with the need of surgical repair.

Conclusions

Cryo-Balloon PVI and PVI using ablation index following the CLOSE protocol are equally efficient in achieving durable PV-isolation. Approximately 7 % of the patients with clinically paroxysmal AF are having extra-pulmonary vein AF sources resp. triggers.

Table 1: Procedural data