Post-ablation antiarrhythmics and AF recurrence

PHILADELPHIA, PENNSYLVANIA. Early recurrence of atrial arrhythmias (atrial fibrillation, flutter or tachycardia) is common following a pulmonary vein isolation (PVI) procedure, but does not necessarily indicate failure of the procedure. Nevertheless, such recurrences are disturbing to the patient and may result in the need for cardioversion and hospitalization. Some electrophysiologists (EPs) prescribe antiarrhythmics to be taken for a certain period following the ablation, while other just prescribe beta- or calcium channel blockers (AV node blocking agents) or no drugs at all.

In 2009 EPs at the University of Pennsylvania reported that ablatees on antiarrhythmics post-ablation were significantly less likely to experience a prolonged arrhythmia recurrence during the first 6 weeks than were patients on AV node blocking agents only (13% vs. 28%). The Pennsylvania group now reports the results of a further 20-week follow-up, bringing the total follow-up time to 6 months.

The experimental group consisted of 110 paroxysmal afibbers (71% men) aged between 46 and 64 years. They had suffered from AF for an average of 6.5 years; 50% had hypertension, and 12% had coronary artery disease. After undergoing a pulmonary vein antrum isolation procedure (Natale protocol), the participants were randomized to receive an antiarrhythmic + AV node blocking agent, or just an AV node blocking agent for a 6-week period immediately following the procedure. Thirty-four percent of members of the antiarrhythmic group were prescribed flecainide, 26% propafenone, 36% sotalol, and 4% dofetilide (Tikosyn).

Ignoring arrhythmias during the first 6 weeks (blanking period), 72% of patients in the antiarrhythmic group were AF-free at the 6-month follow-up (no recurrence during the period 6 to 26 weeks post-ablation) as compared to 68% in the group receiving beta- or calcium channel blockers only. This difference is not statistically significant indicating that antiarrhythmic therapy during a 6-week period post-ablation does not prevent arrhythmia recurrence at 6 months. However, there was a strong correlation between lack of recurrence during the 6-week blanking period and AF-free status at 6 months. In the group with no recurrence during the blanking period, 84% were AF-free at 6 months as compared to only 38% who experienced early recurrence.

The researchers conclude that, although short-term antiarrhythmic therapy decreases early recurrence, it does not prevent arrhythmia recurrence after the blanking period. They speculate that the main factor determining recurrence is electrical reconnection between isolated veins and the left atrium – a progression which would not be affected by antiarrhythmic therapy.

Leong-Sit, P, Gerstenfeld, EP, et al. Antiarrhythmics after ablation of atrial fibrillation – six-month follow-up study. Circulation: Arrhythmia and Electrophysiology, Vol. 4, February 2011, pp. 11-14

Editor’s comment: The absence of early recurrence is clearly of huge importance in determining medium- and long-term outcome. The 2009 Ablation/Maze Survey found that ablatees who had experienced no recurrence in the last 6 months of the 12-month period following ablation had a 93% chance of being afib-free at 4 years, while the chance for those who experienced recurrences was only 50%.