Background: Lack of an irrigated-tip magnetic catheter has limited the role of remote-controlled magnetic navigation (Niobe II, Stereotaxis) for catheter ablation of atrial fibrillation (AF).
Methods and results: A novel 3.5-mm-tip irrigated magnetic catheter (group 1, Thermocool Navistar RMT, Biosense Webster) was used for 3D left atrial reconstruction (CARTO RMT) and remote-controlled magnetic pulmonary vein isolation. A redesigned catheter was used in group 2. The primary end point was wide area circumferential pulmonary vein isolation confirmed by spiral catheter recording during ablation; secondary end points included procedural data, complications, and AF recurrence. Fifty-six consecutive patients [group 1: 28 patients, 22 males, age 64 (38 to 78) years, left atrium: 47 (34 to 52) mm; paroxysmal AF: n=21, persistent AF: n=7; group 2: 28 patients, 20 males, age 60 (24 to 78) years, left atrium: 40 (35 to 53) mm; paroxysmal AF: n=18, persistent AF: n=10] were included. The primary end point was achieved in a total of 52 of 56 (93%) patients. Median procedure duration was 315 (125 to 550) minutes (group 1: 370 [230 to 550] minutes; group 2: 243 [125 to 450] minutes). Median fluoroscopy exposure to the investigator was reduced by 31%. Tip charring in 17 of 28 (61%) and complications in 3 of 28 (11%) patients in group 1 resulted in a catheter redesign. Sinus rhythm was maintained by 35 of 50 (70%) patients during a median follow-up period of 545 (100 to 683) days.
Conclusions: Remote-controlled magnetic AF ablation with real-time verification of pulmonary vein isolation is feasible with a comparable success rate to manual ablation. Safety improved after a redesign of the catheter.