Background: This first-in-man study evaluated the long-term safety and efficacy of a new multi-electrode radiofrequency (RF) balloon catheter (HELIOSTAR, Biosense Webster, Irvine, CA, USA) to achieve pulmonary vein isolation (PVI).
Methods: Patients with drug refractory paroxysmal atrial fibrillation were enrolled. Neurological assessment, cardiac and cerebral MRIs were performed pre and post procedure. Oesophageal endoscopy (OGD) was performed 48 hours post procedure. Ablation was delivered at each PV at 15 Watts for 60 seconds (electrodes adjacent to the posterior wall limited to 20 seconds). Adenosine was administered to confirm PVI. Follow up was for 12 months post procedure.
Results: Thirty-nine patients underwent catheter ablation from four centres. Mean age was 60.7 ± 10.0 years with 23 (57.5%) being male. The only significant complication was a phrenic nerve palsy in one patient. Median procedure time was 100 (81–120) minutes with median total radiofrequency (RF) delivery time of 5.9 (4.5–7.9) minutes. Mean ablation deliveries per patient was 7.3 (5.0–9.0).
Confirmation of isolation after first delivery was performed with the Lasso Catheter on 137 of 152 PVs of which 79.6% (109/137) achieved isolation with a single delivery of RF energy. Of 38 RIPVs that were treated only one acute reconnection (2.6%) was observed. Of 33 RIPVs evaluated following single delivery of ablation 27 (81.8%) were isolated. Acute PV reconnection was seen in 4.6% (7/150) of PVs All treated PVs (152/152) were isolated by the RF balloon at end of procedure.
Evaluation of PV diameter pre and post procedure revealed no moderate or severe narrowing with mean narrowing ranging from 1.9–4.3%. Post ablation OGD excluded oesophageal injuries in all patients. Post procedure neurological assessment reported no new clinical findings. Cerebral imaging did reveal post procedure asymptomatic lesions in 9 of 38 (23.7%) patients which resolved within three months.
Two patients were lost to follow up. Freedom from documented atrial arrhythmia at 12 months was 89.2% (33/37) and 75.7% (28/37) of patients were free from atrial arrhythmia and off anti-arrhythmic medications.
Conclusion: The HELIOSTAR RF balloon catheter allows for rapid and safe PVI with majority of PVersus only requiring one application.