Injections of botulinum toxin into epicardial fat pads during cardiac surgery may provide long-term suppression of atrial fibrillation, according to results from a randomized, placebo-controlled trial published Oct. 20.
Sixty patients with a history of atrial fibrillation, who were undergoing coronary artery bypass graft surgery, were randomized to an injection of botulinum toxin or saline into each epicardial fat pad during surgery.
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Data from 12 months of monitoring via an implantable loop recorder showed patients who received the botulinum toxin injections had a significantly reduced incidence of atrial fibrillation, compared with the placebo group in the 30 days after surgery (7% vs. 30%, P = .024) and at 12 months (0% vs. 27%, P = .002).
Both groups showed significant decreases in heart rate variability after surgery, but at 3 months, these had largely recovered in the placebo group and remained depressed in the botulinum toxin group until 6 months (Circ Arrhythm Electrophysiol. 2015 Oct 20. doi: 10.1161/CIRCEP.115.003199).
No patients in the botulinum group developed persistent atrial fibrillation or required antiarrhythmic therapy or interventions, and there were no significant differences between the two groups in other outcomes such as hospital length of stay or postoperative complications.
“The blocking effects are temporary and recover in 1 to 6 months, depending on the injection site [but] for patients with a high short-term risk of postoperative AF after cardiac surgery, temporary suppression of AF without any destruction of the anatomic structures is clinically desirable,” wrote Dr. Evgeny Pokushalov of State Research Institute of Circulation Pathology, Novosibirsk, Russia, and coauthors.
No conflicts of interest were declared.