The AF-FICIENT magnetic resonance imaging and endoscopy safety substudy: A visually guided radiofrequency balloon ablation catheter for pulmonary vein isolation

BACKGROUND: Early experience with a novel multielectrode saline-irrigated radiofrequency balloon (RFB) catheter with an integrated camera system found that it was safe and effective in performing single-shot pulmonary vein isolation (PVI) for atrial fibrillation. OBJECTIVE: The purpose of this study was to further assess potential treatment risks by looking for subclinical events. METHODS: The study was performed at 2 sites. Patients underwent PVI by RFB. A control group underwent conventional point-by-point radiofrequency ablation. Stroke scale questionnaire and brain magnetic resonance imaging (MRI) were performed before and after the ablation procedure, and esophageal endoscopy was performed after the procedure in RFB patients only. RESULTS: We enrolled 27 patients in the RFB group and 15 patients in the control group. The RFB and control groups were well matched [predominantly male: 62% vs 53%; CHA(2)DS(2)-VASc score: 1.9 ± 1.3 vs 1.5 ± 1.6; mean age 60 years in both groups]. All patients underwent successful ablation and completed study assessments. Clinically silent, new MRI diffusion weighted imaging cerebral lesions were observed in 8 patients (30%) in the RFB group and 1 patient (7%) in the control group, and 11 susceptibility weighted imaging lesions in the RFB group and 1 in the control group. Endoscopy showed a minor thermal injury in 1 patient in the RFB group. CONCLUSION: An increased rate of clinically silent cerebral events was seen in the RFB group. A low rate of esophageal thermal injury was observed.