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CHICAGO -- Antiarrhythmic drugs ineffective before atrial fibrillation ablation help prevent recurrence when continued beyond the blanking period after the procedure, the POWDER-AF (Pulmonary Vein Isolation with versus without Continued Antiarrhythmic Drug Treatment in Subjects with Recurrent Atrial Fibrillation) trial showed.

For patients free from arrhythmia at 3 months after ablation for paroxysmal atrial fibrillation, continuing their previously ineffective antiarrhythmic medication through to 1 year boosted the proportion still free of atrial tachyarrhythmia at that point from a respectable 78.1% off-drug to 97.3% on-drug (P<0.001).

Continued use also lowered the rate of repeat ablation (HR 0.053, P=0.004) and unscheduled visits (HR 0.055, P=0.005) without any significant decrement in quality of life, Mattias Duytschaever, MD, PhD, of St. Jan Hospital in Bruges, Belgium, reported here at the Heart Rhythm Society meeting.

Ablation plus drugs is an "alternative and valid treatment strategy," Duytschaever suggested at the late-breaking clinical trial session.

However, when asked if this is a strategy he is now recommending for patients, he said: "The answer is simple: No. But that is not the point. The point is, first of all, in real life 60% are continuing antiarrhythmic drugs. We don't know why they're taking it ... Now at least I know there is an antiarrhythmic beneficial effect in those patients.

"And it has implications," Duytschaever continued. "For instance, if the patient is continuing antiarrhythmic drugs like so many patients are and he asks to stop the drug, it's wise to tell him it might lead to recurrence. And vice versa, if the patient has stopped the drug and he wants to discuss with you if he needs a repeat ablation, it is still wise to offer options and explain that the antiarrhythmic drug might be enough to close the small residual gap. So the study provides data to further optimize our patient management, rather than to say this is what I'm going to do."

The co-moderator of the session, Andrea Russo, MD, director of the Electrophysiology and Arrhythmia Service of Cooper University Hospital in Camden, N.J., called the study "very clinically applicable" and "practical."

"It's a discussion. There are some people who really want to be off everything," added the session's co-moderator, Christine Albert, MD, PhD, director of the Center for Arrhythmia Prevention at Brigham and Women's Hospital in Boston. "This just gives us data to say if someone says to me, 'Am I more likely to have AF if I come off medication?' I can say yes. Before, I would say I don't know."

The trial included all 153 patients at three Belgian centers who were still on a previously ineffective antiarrhythmic drug 3 months after a first contact-force guided pulmonary vein isolation procedure for paroxysmal atrial fibrillation and free from this arrhythmia at the end of the blanking period. Patients with an enlarged left atrium, low ejection fraction, recent bypass, or MI, awaiting cardiac surgery, unstable angina, uncontrolled heart failure, pregnancy, or life expectancy less than 12 months were excluded.

Patients largely remained on their same medication, although amiodarone (Cordarone, Pacerone, Nexterone) users were switched to a different drug.

Duytschaever said that with little incentive to stay on medication, 7.8% of patients discontinued due to adverse events. Patients reported exercise intolerance and fatigue also in 7.8% of cases each, and impotence was reported as a drug-related adverse event in 1.3%.

Study limitations included the lack of blinding, the fact that there was no continuous ECG monitoring, and the relatively selected patient population.

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