Pulmonary vein remapping: Adequate shortcut or cut too short?

Abstract

d s g r i d The selection of an adequate end point remains a cumbersome task for both the trialist and the clinician. For catheter ablation of an open accessory pathway, acute and chronic success can be easily assessed by the patients’ symptoms and a 12-lead electrocardiogram. Atrial fibrillation (AF) is a much more complex arrhythmia. Therefore, procedural end points for AF ablation are more ambiguous. It was demonstrated that the proportion of patients exclusively documenting asymptomatic AF episodes might rise up to 37% after an ablation procedure. his highlights the fact that the clinical success rate not only s dependent on the ablation procedure itself but is also a unction of follow-up intensity: the more sophisticated tools or follow-up are used, the more AF recurrences will be etected. Thus, the appraisal of an AF therapy efficacy is etermined by the appropriate end point selection and may e confounded by suboptimal AF detection strategies. Conersely, the assessment of procedural efficacy of novel abation technologies solely based on the clinical success may ot be adequate. Following the pioneering observation that paroxysmal F is typically initiated by triggers located in the pulmonary eins (PVs) in a subgroup of AF patients, electrical PV isolation (PVI) was established as the cornerstone of any AF catheter ablation procedure by the HRS/EHRA/ECAS expert consensus statement. Consequently, any novel device eveloped for PVI procedures aims at high acute PVI rates. owever, chronic device efficacy is usually not judged by ts primordial performance such as durable PVI but is most ommonly determined by a clinical end point such as freeom from AF. In this regard, Dukkipati et al, in this issue of Hearthythm, inaugurated a novel end point analyzing the direct ffect of the ablation device. During this multicenter trial, atients were asked to return for a repeat electrophysiologic tudy irrespective of their symptomatology in order to asess the reconnection of previously isolated PVs 105 44 ays after a PVI procedure by using the endoscopic laser alloon catheter. This remapping strategy mimics a true cientific bench experiment aiming at a “dose-response” nalysis disregarding complex pathophysiologic mecha-