Boston, MA - The dig against electrophysiologists claiming to cure atrial fibrillation (AF) with catheter ablation has always been the lack of long-term clinical data. Although the results might look good at 30 days or even one year, there were no clinical data showing the long-term efficacy of the procedure for AF. New follow-up data of patients who underwent pulmonary vein isolation have shown that catheter ablation appears to be able to keep patients free from AF as long as five years, at least in the relatively easy-to-treat paroxysmal-AF patient cohort [1].

"The question of cure was the context in which we conducted this study," lead investigator Dr Thomas Arentz (Hezzentrum, Bad Krozingen, Germany) told heartwire. "We contacted our earliest patients who were successfully ablated five years ago, and what we have seen in this group of patients with idiopathic atrial fibrillation was that the long-term results were very good. Of these patients, 90% appeared to be cured of their atrial fibrillation at five years."

The results of the study were presented this week at the Heart Rhythm Society 2006 Scientific Sessions in Boston, MA.

Earliest ablation cases

Dr Thomas Arentz

To address the question of long-term cure, Arentz and colleagues turned their attention to patients who underwent ostial-segmental pulmonary vein isolation at their center in 1998. In total, 30 patients, all of whom were free of AF at one year without antiarrhythmic drug therapy, completed a questionnaire regarding symptoms and underwent 24-hour Holter-monitor testing.

At five years, 27 of the 30 patients had no symptoms of AF and no AF during the 24-hour Holter monitoring. Three of the 27 patients had a second ablation procedure an average of 14 months after the first procedure for recurrence of AF. One patient had additional linear lesions near the roof of the left atrium and between the lower pulmonary vein and mitral annulus during the second ablation procedure. Of the three patients who had a recurrence of AF, one had persistent AF and two had rare episodes of paroxysmal AF requiring antiarrhythmic drug therapy.

Arentz told heartwire that the pulmonary vein isolation technique is relatively easy for experienced centers to replicate. While the ablation strategy might vary from center to center, with some operators creating additional linear lesion sets, ostial-segmental pulmonary vein isolation appears sufficient to cure AF in this cohort, he said.

Regarding the ablation technique in paroxysmal-AF patients, Arentz said the same one can be used as his group used in 1998 because the results are very good. "You can do pulmonary vein isolation in those patients with paroxysmal atrial fibrillation and achieve a high success rate," he said. "But in other patients, those with chronic or persistent atrial fibrillation or those with organic heart disease, the substrate is not only in the pulmonary veins but outside of it and requires other lesions, as well as substrate modification."

As these were some of the earliest ablation cases, the patient population included only those with paroxysmal AF. Most of the patients were young, average age 51 years, and only six patients had documented heart disease. In addition, most patients had a normal left atrium. Arentz stressed that the long-term results apply to this patient cohort only and that more long-term data are needed, since inclusion criteria for ablation have relaxed and more operators are performing ablation in patients with persistent and chronic AF and, more recently, in those with heart disease.