Abstract 3260: Hybrid ablation and Preventive pacing therapy to control persistent ATRIAL FIBRILLATION: THE HAPPI-AF TRIAL
Background: Catheter ablation (ABL) to electrically isolate the pulmonary veins (PV) has proven to be an effective treatment for patients with paroxysmal atrial fibrillation (AF). However, in patients with persistent or permanent AF catheter ablation is associated with a high failure and/or recurrence rate. Preventive pacing therapies (PPT) may be effective in preventing AF recurrence and reducing AF burden in paroxysmal AF. The HAPPi-AF study was conducted to evaluate the effectiveness of the combination of PPT and catheter PV ablation in pts with chronic AF.
Methods: Pts with symptomatic persistent or permanent and drug refractory AF were implanted with a Vitatron Selection 9000 device and randomized to three groups: A: PPT, B: ABL and C: PPT+ABL. Pts were cardioverted if in AF at device implantation and/or after completion of the ablation procedure (which consisted mainly of circumferential PV isolation). Follow-up visits were scheduled at 3, 6, 12 and 15 months after ablation or activation of the PPT. Pts are improved if AF goes from persistent to at least paroxysmal and cured if they are without AF episodes longer than 5 minutes and have no AF burden at 15 months. ‘Improvement’ and ‘Cured’ were determined based on a consensus between pacemaker data and clinical evaluation.
Results: 150 pts were included (72% male, mean age at implantation: 64 years). 11 Patients have been withdrawn for death (2), lead dislodgements (5), missing data (3), or lost to follow-up (1). Observed cure rates were 31%, 33% and 44% and improvements rates were 54%, 65% and 82% for groups A, B and C, respectively. Both cure rates and improvement rates are significantly better in group C compared to group A. No other significant differences were found.
Conclusion: Using a circumferential PV ablation strategy alone, catheter ablation was fairly ineffectual in “curing” patients with chronic AF. The combination of PPT to catheter ablation decreased AF recurrence rate.