<International Circulation>: What is the safety and efficacy of catheter ablation of atrial fibrillation (AF) in long-term follow-up data， especially for hard endpoints?

　　《国际循环》：房颤经导管消融长期安全性和有效性如何，特别是对于硬终点？
　　Dr Reddy: There are two ways to look at that particular question: the first is from an absolute scientific sense， if you look at the outcomes with operators who have a fair amount of experience; and the second way is how you can apply this to the general practice of electrophysiologists in the United States and around the world. For the first， there are now several studies， both single-center and multi-center studies， that show that from a safety perspective the procedure can be performed with a very low incidence of the major complications. The major complications being: procedure-related stroke， pulmonary venous restenosis， atrioesophageal fistula and tamponade requiring pericardiocentesis. So again， from a safety perspective， and even in the multi-center studies， we see good outcomes. From the efficacy side， what we are seeing in all of the major studies， both single-center and even multi-center， is if you look out to one year， ablation clearly outperforms anti-arrhythmic drugs. There are a few caveats to this. Number one is that most of these studies are in patients who have already failed using one anti-arrhythmic drug so the likelihood of them maintaining sinus rhythm with a second drug is already low， so the fact that ablation works much better is in part a reflection of the fact that drugs in general do not work very well. This includes amiodarone even in these particular studies. The second caveat that is important is that while it is certainly true at one year， the long-term results are less clear. There are several studies that show that even if you have success after ablation at the end of one year， if you follow these patients out further – two years， three years， four years – you start seeing an attrition rate. What we are also seeing though is that the reason for this attrition rate， at least in some part and I believe in large part， is related to incomplete pulmonary vein isolation during the procedure. The point I want to try to make is the initial quality of the ablation procedure appears to affect the long-term outcome. But again， it is better than anti-arrhythmic drugs. Returning to the original question – how well can you generalize the outcomes from experienced centers to centers that are just beginning to use it? I think the answer is we just don’t know. Certainly any center that begins performing ablation will have a greater incidence of safety events and they need to be extremely vigilant about following these events and treating their patients. On the efficacy side， you will see lower efficacy in the beginning as each center gains its own experience. I will point again， that anti-arrhythmic drugs do not work well in most of these patients who have failed one drug.

　　Reddy教授：这个问题要从二方面看。第一，是从绝对意义上的科学性上看，这适用于有相当经验的操作者的手术结局。第二，是如何将其应用于美国以至全世界电生理医生的一般实践。就第一点来说，目前有几个研究（单中心或多中心研究）已经表明该手术的主要并发症（包括：操作相关性脑卒中、肺静脉再狭窄、心房-食管蒌和需心包穿刺的填塞）发生率很低，具有很好的安全性。从有效性上看，观察达1年的大型研究（单中心或多中心研究）均显示，消融好于抗心律失常药物治疗。但要注意这样几点，①大部分研究入选患者均为使用1种抗心律失常治疗失败而采用第二种抗心律失常药恢复窦性心律的可能性很低者，因此消融可能是更好的选择，在某些包括胺碘酮的研究中，结论同样如此；②即使观察时间达到1年，其长期结局也是不能轻易确定的；现在已经出现了消融成功1年以上，继续观察2年、3年、4年这样的研究，观察指标是房颤率，它与术中肺静脉剥离不完全有关（我想告诉大家的就是初始消融质量影响长期结局）；但即使这样，也好于抗心律失常药。就第二点来说，怎样才能使好的结局从有经验的中心扩展到刚刚起步的中心呢？这个问题我确实无法回答。任何刚刚开展消融工作的中心都会有比较高的安全事件发生率，他们需要高度警惕这些事件的发生并正确处理相关患者；同样，这些中心的有效率由于经验不足也会比较低。最后，我想再次强调，抗心律失常药在第一种药物治疗失败的大部分患者中无效。