Abstract
Introduction
Pulmonary vein isolation (PVI) is the central element in the ablation of atrial fibrillation (AF), and can be obtained with different ablation modalities. The duty-cycled circular multi-pole catheter PVAC® (Medtronic) allows linear application of radiofrequency energy, with the production of circumferential lesions. Conceptually, it can make ablation simpler and faster in patients with favorable anatomy.
Objectives
To evaluate the safety and efficacy of ablation with a PVAC® catheter and to compare it with the conventional technique point-by-point (PbP) with irrigated catheter.
Methods
Clinical trial with single-blinded patients with AF refractory to antiarrhythmic therapy, randomized (1: 1) for ablation with PVAC® or PbP. The ablation strategy consisted of PVI, complemented with ablation of the cavo-tricuspid isthmus in patients with history of concomitant flutter. Monitoring was performed with a 7-day event loop recorder at 3, 6 and 12 months and annually from the 2nd year. Success was defined by AF-free survival or any maintained supraventricular tachycardia (duration > 30seconds).
Results
354 patients (67.5% males, 58 ± 12 years, PbP: 175, PVAC: 179) were included, of which 59.1% had paroxysmal, 26.2% short-standing persistent and 14.7% had long-standing persistent AF. Baseline characteristics were similar between groups. Among patients treated with PVAC, 93.1% of the pulmonary veins were isolated (620/666), similar to the 98.3% immediate success of the PbP group (697/709). Although the complication rate was similar in both groups (PVAC: 4.9% vs. PbP: 7.8%; P = NS), the risk of hemopericardium was lower with PVAC (0% vs. 4.6%; P = 0.013). Two patients treated with PVAC developed stroke (1.13% vs. 0%; P = NS). The duration of the procedure was lower among the patients treated with PVAC [136 (100-180) vs. 230 (188-270) min; P <0.001], with no difference in fluoroscopy time [24.4 (14.5-36.8) vs. 27.1 (17.0-45.0) min]. The success rate after 1st ablation at 36 months was 68%, with no differences between groups. The success rate after multiple ablations increased to 85.8%, with no differences between groups.
Conclusion
The multipolar PVAC catheter can represent an added value in AF ablation, making the procedure simpler and faster, ensuring similar efficacy to the conventional technique and with a lower risk of cardiac tamponade. The present trial suggests the need for clinically manifested stroke risk surveillance, which may be increased with this technique.
Abstract Figure.