In patients with atrial fibrillation (AF), radiofrequency ablation worked as well as or better than drugs to reduce paroxysmal AF, according to late-breaking research presented at the American Heart Association's Scientific Sessions 2011.

Anti-arrhythmic medications can control the heart rhythm and symptoms of atrial fibrillation (AF), but many patients don't respond well. Another option for stabilizing the heartbeat is delivering high frequency alternating current through a catheter to destroy the small bits of heart tissue that cause AF. In this case, researchers targeted tissue surrounding the pulmonary veins. This treatment option has not previously been tested for patients who haven't tried drug treatment.

Researchers randomized participants to either radiofrequency ablation (146) or an anti-arrhythmic drug (148). They assessed the patients at the study's start, and at 3, 6, 12, 18 and 24 months.

Each time, patients wore a portable heart monitor for seven days. Significant findings included:

• At 3, 6, 12 and 18 months, there was no significant difference in the amount of time patients in the two groups experienced AF (AF burden) nor in the cumulative AF burden.
• At 24 months, the ablation group did have significantly less AF burden than the drug-treated patients.
• Twenty-two radiofrequency ablation patients (15 percent) had AF compared to 43 (29 percent) treated with drugs.
• Ten ablation patients (7 percent) had symptomatic AF episodes compared to 24 (16 percent) in the drug group.

"Ablation therapy is at least as good and tends to be better than drug therapy at preventing episodes of atrial fibrillation," said Jens Cosedis Nielsen, M.D., lead researcher and professor of cardiology at Aarhus University Hospital in Denmark.

Of the patients primarily treated with ablation, 13 needed supplementary drugs and 54 patients who didn't improve with drugs underwent supplementary radiofrequency ablation.

"Not every patient should be offered ablation, but this research should be discussed with patients when a physician feels it is a viable treatment option," Nielsen said.

Co-authors are Arne Johannesen, M.D., D.M.Sci.; Pekka Raatikainen, M.D.; Gerhard Hindricks, M.D.; Hakan Walfridsson, M.D.; Ole Kongstad, M.D.; Steen Pehrson, M.D., D.M.Sci.; Anders Englund, M.D.; Juha Hartikainen, M.D.; Leif Spange Mortensen, M.S.; and Peter Steen Hansen, M.D., D.M.Sci.

Biosense Webster, Inc., and the Danish Heart Foundation funded the study.