房颤消融失败后应再消融而非用药

丹佛——一项随机试验结果显示，当首次消融治疗阵发性房颤遭遇失败时，再次进行消融比抗心律失常药物治疗更加有效。

美国哥伦比亚大学的Jonathan Steinberg博士在心律学会(HRS)2013年会上报告称，症状性阵发性房颤的首次消融治疗成功率通常约为60%，而其余40%首次消融失败者应当如何治疗目前尚无定论，此前尚无有关这一问题的随机临床试验证据可供参考。

图. 药物治疗组和再次消融组的3年关键结局指标对比。

这项研究纳入了154例在首次接受消融治疗(仅进行肺静脉隔离)后3个月内复发的症状性阵发性房颤患者。所有受试者被置入心电记录器(ILR)以追踪房性心律不齐事件。然后研究者将这些受试者随机分组，再次行消融术(仅限于再隔离肺静脉)或根据指南给予抗心律失常药物治疗。药物选择由施治的医生自行决定，包括3个选项：丙胺苯丙酮450~900 mg/d、索他洛尔160~320 mg/d，或氟卡尼200~400 mg/d。多数病例选用的是丙胺苯丙酮，平均剂量为579 mg/d。

ILR显示，随机化时的平均房颤负担为15%。在主要终点——随访36个月时的房颤负担——方面，再次消融组与药物治疗组分别为5.6%和18.8%。再次消融组在各项次要终点方面也均优于药物治疗组。

在3年随访期间，研究者每3个月评估1次ILR数据。结果显示，早在第3个月时，药物治疗组的房颤负担就已明显高于再次消融组(3.3% vs. 1.9%)，在此后的12个月内，药物治疗组的房颤负担逐渐增加，并且在剩余的随访时间内出现了更大幅度的上升。而再次消融组的房颤负担呈现出另一种变化模式：在最初12~15个月内保持在低位，仅有轻微增加，之后逐渐上升直至随访结束。

药物治疗组和再次消融组分别有30%和75%的患者在1年内未发生任何房性心律失常。至第3年末，两组分别有12%和58%的患者仍然未发生任何房性心律失常。

再次消融组的并发症为2例心脏填塞，而药物治疗组有49例患者(占64%)因不能耐受或无效而停药。

会议共同主席、约翰霍普金斯大学的Gordon Tomaselli博士表示，鉴于几乎所有抗心律失常药物均有潜在的致心律失常作用，如果能在研究中设置一个非抗心律失常药物对照组将会更理想。

Steinberg博士报告称无利益冲突。

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By: BRUCE JANCIN, Cardiology News Digital Network

DENVER – After a failed first ablation procedure for paroxysmal atrial fibrillation, redo ablation proved more effective than did antiarrhythmic drug therapy in a randomized trial, Dr. Jonathan Steinberg reported at the annual meeting of the Heart Rhythm Society.

The success rate of a first ablation procedure in patients with symptomatic paroxysmal AF is typically about 60%. What to do for the 40% who are nonresponders has been unclear, with no prior randomized clinical trial evidence available to guide decisions, noted Dr. Steinberg of Columbia University, New York.
 
The study comprised 154 patients with recurrent symptomatic paroxysmal AF 3 months after an initial ablation procedure involving only pulmonary vein isolation. All participants received an implantable loop recorder to track atrial arrhythmic events.

They were then randomized to redo-ablation limited to reisolation of the pulmonary vein, which was successfully accomplished in all instances, or to guideline-based antiarrhythmic drug therapy. The choice of drug was left to individual investigator discretion. The three options were propafenone at 450-900 mg/day, sotalol at 160-320 mg/day, or flecainide at 200-400 mg/day. Propafenone was selected in the majority of cases, at an average dose of 579 mg/day.

The average AF burden as measured by implantable loop recorder at randomization was 15%. The primary study endpoint was AF burden at 36 months of follow-up, which was 5.6% in the redo-ablation group compared with 18.8% in the antiarrhythmic drug group.

Secondary endpoints uniformly favored redo-ablation as well.

Data from the implantable loop recorders was evaluated every 3 months during 3 years of follow-up. As early as 3 months into the study, the group given antiarrhythmic drugs had an AF burden of 3.3%, significantly higher than the 1.9% rate seen in the redo-ablation group. Thereafter, the drug therapy group experienced a gradual increase in AF burden throughout the first 12-15 months, followed by a much more substantial increase during the remainder of the study.

"The redo-ablation group had a different pattern" of AF burden, Dr. Steinberg observed. "It was low throughout the first 12-15 months, with just a slight increase, and it then rose only gradually over time until the 36-month end of the study."

Freedom from any atrial tachyarrhythmia at 1 year was 30% in the antiarrhythmic drug therapy group and 75% in the redo-ablation group. By 3 years, 12% of those in the drug therapy group were free of atrial tachyarrhythmias as were 58% in the redo-ablation group.

Complications in the redo-ablation group consisted of two cases of cardiac tamponade. In contrast, 49 patients, or 64%, in the antiarrhythmic drug therapy group discontinued medication due to intolerance or ineffectiveness.

Session cochair Dr. Gordon Tomaselli of Johns Hopkins University, Baltimore, said that in light of the potential proarrhythmic effects of virtually all antiarrhythmic drugs, it would have been useful to include a no-antiarrhythmic drug control group in the study.

Dr. Steinberg reported having no conflicts of interest.