Why amiodarone failed to lower the rate of recurrence six months after catheter ablation for atrial fibrillation

This editorial refers to ‘Recurrence of arrhythmia following short-term oral AMIOdarone after CATheter ablation for atrial fibrillation: a double-blind, randomized, placebo-controlled study (AMIO-CAT trial)’†, by S. Darkneret al., on page 3356. Recurrence of atrial fibrillation (AF) early after pulmonary vein isolation (PVI) is a common event.1 In terms of long-term outcome, the implications of recurrence of arrhythmia within the first months following ablation are thought to be different from arrhythmias occurring beyond the 3-month blanking period.1 Transient effects, such as a high catecholamine state, delayed maturation of ablative lesions and the inflammatory process caused by acute atrial tissue injury, may foster an early pro-arrhythmic milieu. Consequently, attempts to expose the patients to an early re-do ablation procedure should be weighed against the likelihood that these arrhythmias will subside spontaneously. Patients are frequently treated post-operatively with anti-arrhythmic medication that was previously ineffective. A randomized, prospective study demonstrated that the use of Class IC and Class III (excluding the use of amiodarone) anti-arrhythmic drugs, given for 6 weeks post-PVI in patients with a history of paroxysmal AF, reduced the rate of early recurrence of arrhythmia but had no effect on the recurrence rate after 6 months.2,3