Fewer Recurrences on Continued Antiarrhythmic Therapy After AF Ablation

Fran Lowry

May 18, 2017

CHICAGO, IL — Continuing previously ineffective antiarrhythmic drug therapy (AAD) after catheter ablation by pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) can significantly reduce the 1-year rate of tachyarrhythmia recurrence, suggests new research[1].

Dr Mattias_Duytschaever

"Continuing antiarrhythmic drug therapy after ablation is a valid and alternative treatment strategy in patients with paroxysmal AF," Dr Mattias Duytschaever (St Jan Hospital, Brugge, Belgium) said here at the Heart Rhythm Society (HRS) Scientific Sessions 2017.

"In real life, approximately 50% of patients continue antiarrhythmic drug therapy after ablation for various reasons, such as anxiety, out of habit, extrasystoles, or because of a presumed synergistic effect," Duytschaever told heartwire from Medscape.

However, "So far, no randomized study has investigated whether antiarrhythmic drug therapy, beyond the blanking period, reduces recurrence of atrial tachyarrhythmias after pulmonary vein isolation," Duytschaever said.

"Hence the rationale for our study," the Pulmonary Vein Isolation With Versus Without Continued Antiarrhythmic Drug Treatment in Subjects With Recurrent Atrial Fibrillation (POWDER-AF) trial.

Duytschaever and his colleagues randomized 153 patients still on their AAD but free of AF 3 months after a de novo contact-force–guided PVI for paroxysmal AF to either continue (n=77) or to discontinue (n=76) their antiarrhythmic drug.

The trial's primary end point was the documented recurrence of any atrial tachyarrhythmia (atrial fibrillation, atrial flutter, or atrial tachycardia) lasting more than 30 seconds from the start of randomization 3 months after ablation to 12 months after the procedure.

One-day Holter monitoring was performed at 3 and 6 months after PVI, and 7-day Holter monitoring was done at 12 months after PVI; additional Holter monitoring could be performed due to symptoms.

At 12 months, there were  significantly fewer documented ATAs in patients randomized to continue antiarrhythmic drug therapy.

Arrhythmias occurred in 2.7% (n=2) patients who continued antiarrhythmic drug therapy, compared with 21.9% (n=16) of those who discontinued therapy (P<0.001).

"The freedom from atrial fibrillation in the patients after PVI without drugs was 78%, which confirms a good outcome with cardiac ablation, but by adding drugs, you can reach up to 97% freedom from atrial fibrillation," Duytschaever said.

In addition, patients who continued AAD had a lower occurrence of repeat ablation (1.3%) vs those who stopped therapy (17.1%; odds ratio [OR] 0.06, 95% CI 0.001–0.46); and lower rates of unscheduled visits (2.6%) compared with those who discontinued therapy (19.7%; OR 0.11, 95% CI 0.02–0.49).

Quality-of-life scores were similar in both groups.

"Physicians should stop the pro-con debate on 'ablation or drugs' and  focus instead on the therapeutic synergy of 'ablation and drugs,' " according to Duytschaever.

"If patients are free of AF after PVI while taking antiarrhythmic drug therapy, they should be aware that if they want to stop their drug therapy, that there is an increased likelihood of recurrence. And vice versa: in patients experiencing recurrence of AF while off antiarrhythmic drug therapy, they should be aware that restarting a previously ineffective antiarrhythmic drug therapy might be enough to prevent recurrence and be an alternative to repeat ablation."

The study was funded by Biosense. The authors reported no relevant financial relationships.

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