HRS: Antiarrhythmic Drugs Help Calm the Atrium After Ablation

By Crystal Phend
SAN FRANCISCO,17 may 2008-- A short course of antiarrhythmic drug therapy after ablation to correct atrial fibrillation may improve early outcomes, researchers found.Six weeks of antiarrhythmic treatment after ablation halved the number of patients with recurrent arrhythmia, cardioversion, or hospitalization for arrhythmia (P<0.01), reported Jean-Francois Roux, M.D., of the University of Pennsylvania in Philadelphia, and colleagues here at the Heart Rhythm Society meeting.While many electrophysiologists have followed this strategy empirically, these results from the randomized AntiArrhythmics After Ablation of Atrial Fibrillation (5A) Study provide the first good evidence that it helps patients through the healing period, when arrhythmias tend to occur, Dr. Roux said.
More broadly, the study implies that combination therapy can be beneficial in atrial fibrillation, commented Richard L. Page, M.D., of the University of Washington in Seattle and program chair of the meeting.
"It used to be [a question of] should they be on drugs or should they get a procedure," Dr. Page said, but "it's not an 'either or.'"
Because of the lack of clear evidence and particularly because of the risk of proarrhythmia, Dr. Roux's team prospectively randomized 110 patients who had ablation for paroxysmal atrial fibrillation at a single center to unblinded treatment with atrioventricular-nodal blocking agents alone or with antiarrhythmic drugs.
Choice of antiarrythmic agents was at the electrophysiologists' discretion, but the suggested agents included:
Propafenone (Rythmol) 150 mg three times a day or flecainide (Tambocor) 100 mg twice a day for patients with normal left ventricular function and no obstructive coronary artery disease.
Sotalol (Betapace, Sorine) 80 mg twice daily for those with normal left ventricular function with coronary artery disease.
Sotalol 80 mg twice a day or dofetilide (Tikosyn) 500 mcg twice a day for patients with abnormal left ventricular function.
These agents were started the night of the procedure. For the first four weeks thereafter, all patients wore an auto-trigger transtelephonic monitor with daily transmission. At six weeks, patients were reevaluated and those in the antiarrhythmic group discontinued drug therapy.
The study was stopped early when the benefit of drug therapy reached statistical significance on periodic review.
Combination ablation and drug therapy resulted in significantly fewer adverse events in the composite primary endpoint than seen with ablation alone. The rate of persistent or severe atrial arrhythmias, need for cardioversion or hospital admission for atrial arrhythmia, and intolerance of the antiarrhythmic agent requiring drug cessation or change was 17% with antiarrhythmic drugs versus 40% without (P<0.01).
The benefit was driven by fewer arrhythmia recurrences (one versus 14, P<0.01).
Adverse effects of antiarrhythmic drugs were seen in three patients -- one case each of rash, severe fatigue, and headache -- but this rate was not significant compared with the control group (P=0.07).
Likewise, the advantage of combination therapy over the first six weeks was significant when restricted to the hard endpoints of recurrent arrhythmia for more than 24 hours, hospitalization for arrhythmia, and cardioversion (11% versus 26%, P<0.05).
Longer-term follow-up may be important because previous studies have shown that early arrhythmias don't necessarily predict later outcomes, Dr. Roux noted.
However, the study used the six-week period of antiarrhythmic drug therapy typically used in the clinic, he noted.
Dr. Roux reported no financial disclosures. Dr. Page reported being a paid consultant to sanofi-aventis.
Primary source: Heart Rhythm Society meetingSource reference:Roux J-F, et al "AntiArrhythmics After Ablation of Atrial Fibrillation (5A) Study" HRS Meeting 2008.