The Tribulations of Atrial Fibrillation Ablation Trialists.

Abstract

Pulmonary vein isolation (PVI) with catheter ablation has been demonstrated to be an effective method for controlling atrial fibrillation (AF) in most patients. It is assumed that complete isolation is required for effective treatment and clinical failure is because of electric reconnection of a pulmonary vein (PV). On rare occasions, some electrophysiologists have seen conversion of AF to sinus rhythm with continued fibrillation seen within the PV further supporting this theory (Figure). Aside from anecdotal evidence, the data from observational PV remapping studies and repeat ablations that describe exclusively reisolating veins as the only intervention resulting in a successful outcome after an initial failure further collaborate the importance of complete PVI.1 Figure. Could this patient possibly benefit from an incomplete pulmonary vein isolation strategy? See Article by Kuck et al Still, although PVI has been recommended to be the cornerstone of AF ablation, there has never been a randomized trial that compares PVI with purposeful incomplete PVI as a procedural end point. At first consideration, it may seem obvious that complete PVI should be required as part of an ablation strategy as agreed on by expert consensus.2 However, studies targeting only non-PV triggers and/or non-PV rotors reporting success have raised questions of the central role complete PVI has.3 In addition, chronic PV reconnection is common, and thus, it is assumed that there exists a certain portion of patients who have unintentional incomplete PVI because of this phenomenon, yet still may not have recurrence of AF. This is the reasoning behind the Gap-AF study in this issue of Circulation: Arrhythmia and Electrophysiology .4 This randomized, multicenter trial set out to understand whether an upfront approach of complete PVI (group B) is superior to intentionally allowing for electric reconnection (group A). Two hundred thirty-three patients with drug refractory, symptomatic, …