How much ablation to eliminate atrial fibrillation: Is less more, or is more more?

There has been continual improvement in catheter ablation for symptomatic atrial fibrillation (AF) over the past 15 years. For patients with paroxysmal AF, the single-procedure success rate increased from approximately 30% in 2003 to 70% in 2010. Single-procedure outcomes for persistent AF during that time frame showed less improvement, from approximately 30% to 55%, and long-standing persistent AF showed virtually no improvement over time and was stuck at about 30% to 40%. When things are not going well, ablationists always seem to want to do more rather than figure out how to do better with less. When strokes and neurologic events occur in the periablation period, ablationists give more anticoagulation or use uninterrupted anticoagulation, even though we have demonstrated the procedures can be performed safely with less anticoagulation and with interrupted anticoagulation. Similarly, given the generally poorer outcomes the more persistent the AF, until recently, the trend has been to do more rather than less ablation. For persistent AF, the stepwise approach was introduced approximately 10 years ago. After pulmonary vein isolation (PVI), a strategy of continuing to burn until AF organized or preferably broke seemed to improve outcome. It was assumed that the better outcome in the patients whose AF organized or broke was attributable to the additional ablation and substrate modification. However, it is possible that patients whose AF organizes or breaks with ablation have less abnormal substrate or an easier-to-eliminate AF and are going to have a better outcome regardless of what or how much is ablated. After almost 10 years of many, if not most, ablationists performing very extensive ablation for persistent AF, 3 recently reported randomized trials have questioned the value of such extensive ablation. In the 2C3L study, PVI, a left atrial roof line, a mitral isthmus line, and a caval tricuspid isthmus line were performed in all patients. Patients were then randomized to no additional ablation or to extensive ablation of complex fractionated atrial electrograms until the arrhythmia broke or they had been undergoing ablation for an additional hour. There was a nonstatistically significant trend in favor of better outcomes