PHILADELPHIA, PENNSYLVANIA. Apart from our 2009 Ablation/Maze Survey there is little published data on the long-term outcome of initially successful pulmonary vein isolation (PVI) procedures. Electrophysiologists at the University of Pennsylvania now report on the 5-year outcome for 123 afibbers who had undergone a PVI, plus additional lesions as needed, during the period 2001 to 2003 and had remained afib-free for one year following the procedure without the use of antiarrhythmics. The mean age of the study participants was 54 years, 80% were male, 85% had paroxysmal AF with the remaining 15% having the persistent variety.

A total of 239 patients underwent a segmental PVI and 59% of these patients were afib-free (without antiarrhythmics) without further intervention one year after their initial procedure. Among the 123 one-year "veterans", 84% continued to remain afib-free for 3 years after their initial PVI. The percentage of afib-free participants decreased to 77% at year 4 and 71% at year 5 indicating a recurrence rate of approximately 7% a year.

Persistent afibbers had a 2.8-fold increase in the risk of experiencing a recurrence and older afibbers (57 years) had a 10% greater risk of relapsing than did younger ones (52 years). There was also some indication that a larger left atrial size was associated with a poorer outcome. There was no association between operator experience and long-term success. NOTE: More than likely operator experience would nevertheless be highly important in determining 1-year outcome.

A total of 35 patients experienced recurrent AF an average of 3.3 years after the index procedure. Ten had fewer than 6 episodes a year, while the remaining 25 continued to experience AF episodes despite re-initiation of antiarrhythmics. Fifteen of these patients underwent a repeat ablation an average of 3 years following their initial procedure and 73% remained afib-free 3 years after their second procedure. Including patients who had a second ablation in the total, the 4- and 5-year complete success rates (no AF and no antiarrhythmics) becomes 89% and 81% respectively. In all cases, the recurrence of AF was due to previously ablated pulmonary veins reconnecting electrically with the left atrium.
Tzou, WS, et al. Long-term outcome after successful catheter ablation of atrial fibrillation. Circulation: Arrhythmia and Electrophysiology, Vol. 3, June 2010, pp. 237-42

Editor's comment: It is of interest to compare the above results with those obtained in the 2009 Ablation/Maze Survey. Here 66 afibbers who had remained in normal sinus rhythm for 6 months following their last procedure were followed for up to 7 years. Complete success rate was 83% at year 3-4 and 86% at year 5-6, thus comparable to the 89% and 81% observed in the University of Pennsylvania study. The long-term success rate in our survey was, however, highly dependent on operator experience and the absence of AF episodes during the first 6 months following the procedure.