A minimally invasive surgical procedure to treat antiarrhythmic drug-refractory atrial fibrillation (AF) proved more effective than catheter ablation in two high-risk patient groups but was significantly more likely to result in complications, according to late-breaking research presented at the American Heart Association's Scientific Sessions 2011.

The study is simultaneously published in Circulation: Journal of the American Heart Association.

In their study, researchers compared the efficacy and safety of video-assisted epicardial surgical ablation to pulmonary vein catheter ablation, an established and less invasive technique.

Researchers enrolled 124 patients, 101 of them men, at two sites - St. Antonius Hospital in Nieuwegein, The Netherlands, and the Hospital Clinic at the University of Barcelona in Spain. The patients had a high risk of failing to gain relief of AF from catheter ablation.

Sixty-one patients were randomized to surgical ablation and 63 to catheter ablation; 66 percent had paroxysmal, or sporadic AF, and 34 percent had persistent AF. Results of the study showed:

• One year after the procedures, 36.5 percent of catheter ablation patients were AF-free without drugs versus 65.6 percent of the surgical ablation group, a meaningful difference that varied little regardless of the type of AF, existing preconditions or where the patient was treated.
• Major adverse events during the procedure occurred in 23 percent of surgical patients and 3.2 percent of the catheter group, a significant difference.
• Subsequent adverse events during the one-year follow-up occurred in similar numbers in both groups (12 percent of catheter patients and 11 percent of surgical patients).

"The difference between the surgical group and the catheter ablation group was mostly due to more procedural events. A substantial part consisted of collapsed lungs, which could mostly be managed conservatively, several bleeding complications and two pacemakers. Many adverse events were solved without permanent harm to the patients," said Lucas Boersma, M.D., Ph.D., lead researcher and a cardiologist at St. Antonius.

"The risk of the procedure accompanying the chance for greater success needs to be carefully weighed by physicians and patients."

Previous research suggests results would likely apply to both genders and all races and ethnicities, he said.

Co-authors are Manuel Castella, M.D., Ph.D.; WimJan van Boven, M.D.; Antonio Berruezo, M.D.; Alaadin Yilmaz, M.D.; Mercedes Nadal, M.D.; E Sandoval, M.D.; Naiara Calvo, M.D.; Josep Brugada, M.D., Ph.D.; Johannes Kelder, M.D.; Maurits Wijffels, M.D., Ph.D.; and Lluis Mont, M.D.; Ph.D.

Participating hospitals and a grant from AtriCure partly funded the study.