Ablation of persistent atrial fibrillation using multielectrode catheters and duty-cycled radiofrequency energy.

OBJECTIVES The purpose of this study was to assess the efficacy and safety of a novel, multielectrode, duty-cycled radiofrequency ablation (RFA) system for long-standing persistent atrial fibrillation (AF). BACKGROUND RFA for persistent AF remains a lengthy and challenging procedure. METHODS In 5 European centers, 50 patients with long-standing persistent AF underwent RFA. A circular pulmonary vein (PV) ablation catheter was used for PV isolation. Complex fractionated atrial electrograms were targeted at the interatrial septum using a multiarray septal ablation catheter and in the left atrium using a multiarray ablation catheter. RESULTS During a mean total procedure time of 155 +/- 40 min, complete PV isolation and complex fractionated atrial electrogram ablation were achieved in all patients. In 50% of patients, redo ablation was performed using the same strategy and technology. There were no device-related adverse events. At 6 months, a 7-day Holter electrocardiogram showed >80% AF reduction in 40 of 50 patients (80%), and 32 of 50 (64%) were off antiarrhythmic drugs. At 20 +/- 4 months after the last procedure, 31 of 47 patients (66%) had a >80% reduction in AF burden, with 21 patients (45%) free of AF and off antiarrhythmic drugs. CONCLUSIONS This initial 50-patient multicenter study demonstrates a 80% short-term and 66% success rate at 20 months, with a low complication rate and a relatively short procedure time in patients with persistent AF using 3 anatomically specific multielectrode ablation catheters and low-energy duty-cycled radiofrequency energy.