ORLANDO, FLA. — A minimally invasive surgical procedure to treat 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.
Before catheter ablation was developed in the mid-1990s, AF patients in whom medications didn’t control symptoms could only be treated with surgery that required opening the chest.
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, either because the procedure hadn’t worked previously (67 percent) or because they had an enlarged atrium (one of the heart’s upper chambers affected by atrial fibrillation).
The surgical ablation procedure involves a few small incisions in the chest wall — one for the endoscope (a thin, camera-tipped wire) and the others for surgical tools. The heart continues to beat while the surgeon uses radiofrequency energy to destroy and tissue around the heart that is causing the irregular heartbeats.
In catheter ablation, a doctor inserts long, flexible tubes into the blood vessels of the leg and guides the catheter into the atrium. Radiofrequency energy is delivered through the tip of the catheter to destroy the tissue targeted for 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 Lluís Mont, M.D.; Ph.D.
Disclosures are here: http://newsroom.heart.org/pr/aha/document/Disclosures_for_LBCT.xlsx.
Participating hospitals and a grant from AtriCure partly funded the study.
Statements and conclusions of study authors published in American Heart Association scientific meetings or presentations are solely those of the study authors and do not necessarily reflect the association’s policy or position. The association makes no representation or guarantee as to their accuracy or reliability. The association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific association programs and events. The association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and device corporations are available at www.heart.org/corporatefunding
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