Controversies in ablation of atrial fibrillation

Abstract

Catheter ablation is increasingly widely used to treat atrial fibrillation (AF) and constantly evolving techniques and protocols have led to improved success rates and lower risks of complications in a broad range of patients. However, long-term clinical trial data are still limited and as a result many questions remain unanswered. Particularly in patients with symptomatic paroxysmal AF, high success rates in restoring sinus rhythm (SR) with a low risk of complications are reported by experienced centres. Nevertheless, the continued suppression of AF over time, particularly with regard to the recurrence of asymptomatic episodes of AF which could influence stroke risk, is not yet adequately documented and therefore the safety of discontinuing oral anticoagulation remains unclear. The risk of silent or subclinical complications associated with ablation procedures, the likelihood of autonomic modulation and the long-term impact of ablation on left atrial mechanical function have not yet been fully determined. Limited clinical trial data suggest that catheter ablation may be particularly beneficial for patients suffering from heart failure (HF) secondary to AF, indicating improved left ventricular function and quality of life with the restoration of SR. However, the processes underlying HF and the co-existing morbidities vary from one patient to another and the factors predicting a successful outcome of ablation have not yet been fully defined. Similarly, the consistently higher rates of AF suppression achieved with catheter ablation vs. antiarrhythmic drug therapy shown in comparative clinical trials encourage consideration of this treatment as a potential first-line treatment in certain patients, but whether this is currently justifiable and if so, in which patient subsets, are open questions. This article reviews current approaches to catheter ablation and attempts to address some of the controversies regarding its use.