Episodic amiodarone not advantageous in AF

MedWire News: Episodic amiodarone therapy cannot be recommended for persistent atrial fibrillation (AF), say Dutch researchers, who found that most patients required continuous therapy to adequately suppress arrhythmias.

Amiodarone is the most effective drug used to prevent AF but can cause a range of noncardiac adverse events, particularly when used in high dosages and over long periods of time.

In the present study, Sheba Ahmed (University of Groningen) and colleagues hypothesized that episodic amiodarone therapy would be as effective as continuous treatment, but with an improved safety and tolerability profile.

They tested this in a multicenter trial known as CONVERT, in which 209 patients with recurrent symptomatic persistent AF were randomized to receive either episodic or continuous amiodarone therapy following successful electrical cardioversion and a loading dose of amiodarone.

After a median follow-up of 2.1 years, continuous therapy exhibited a range of advantages over episodic therapy. These included a higher proportion of patients in sinus rhythm (62% vs 48%, p=0.05), a lower incidence of AF recurrence (54% vs 80%, p<0.001), a lower rate of all-cause mortality and cardiovascular hospitalizations (34% vs 53%, p=0.02), and a trend to fewer underlying heart disease-related major events (9% vs 16%).

Conversely, episodic therapy was associated with a nonsignificant trend toward fewer amiodarone-related major events (19% vs 24%), while there was no difference between the groups in the incidence of the primary endpoint – a composite of amiodarone and underlying heart disease-related major events (35% episodic vs 33% continuous).

“Considering the above, episodic amiodarone treatment cannot be advocated for most patients with persistent atrial fibrillation,” Ahmed and co-authors conclude.

“This study shows that episodic amiodarone treatment – in contrast to our expectations – has no clinical advantage over continuous treatment because it did not lower morbidity in patients with persistent atrial fibrillation over 2 years of follow-up.”

The study is published in the Journal of the American Medical Association.

JAMA 2008; 300: 1784–1792