Suppression of Atrial Fibrillation by Botulinum Toxin

Study Questions:

What is the efficacy and safety of botulinum toxin injection into epicardial fat pads for preventing atrial tachyarrhythmias?

Methods:

Patients with a history of paroxysmal atrial fibrillation (PAF) and indication for coronary artery bypass graft (CABG) surgery were randomized to botulinum toxin (Xeomin, Merz, Germany; 50 U/1 ml at each fat pad; n = 30) or placebo (0.9% normal saline, 1 ml at each fat pad; n = 30) injection into epicardial fat pads during surgery. Patients were followed for 1 year to assess maintenance of sinus rhythm using an implantable loop recorder (ILR).

Results:

All patients in both groups had successful epicardial fat pad injections without complications. The incidence of early postoperative AF within 30 days after CABG was 2 of 30 patients (7%) in the botulinum toxin group and 9 of 30 patients (30%) in the placebo group (p = 0.024). Between 30 days and up to the 12-month follow-up examination, 7 of the 30 patients in the placebo group (27%) and none of the 30 patients in the botulinum toxin group (0%) had recurrent AF (p = 0.002). There were no complications observed during the 1-year follow-up.

Conclusions:

The authors concluded that botulinum toxin injection into epicardial fat pads provided substantial atrial tachyarrhythmia suppression both early as well as during 1 year of follow-up, without any serious adverse events.

Perspective:

This study reports that botulinum toxin injection into the epicardial fat pads reduced cardiac autonomic nervous system activity and provided substantial postoperative AF suppression after CABG without any serious adverse events. The favorable reduction of AF was present within the 30-day postoperative window, but also during longer follow-up during 1 year. Additional prospective randomized studies are indicated to validate these findings and to better understand the mechanism by which functional atrial remodeling by botulinum toxin injection may occur.


< Back to Listings