心房細動においてカテーテルアブレーションは薬物よりも有効である（Abstract # 18473）

発作性心房細動に対し高周波アブレーションは抗不整脈薬よりも有効である
Radiofrequency ablation better than antiarrhythmic drug therapy for paroxysmal atrial fibrillation
心房細動（AF）患者の発作性AF軽減において、高周波アブレーションは薬物と同様またはそれ以上に有効であるとのlate-breaking researchの結果が2011年American Heart Association学会で発表された。ある多施設トライアルで研究者らは、294人の患者（平均年齢55±10歳、男性206人）を高周波アブレーション（146人）または抗不整脈薬（148人）に無作為に割り付けた。彼らは患者をスタディ開始時、3、6、12、18および24ヵ月後に評価した。毎回患者らは携帯用心拍モニターを7日間着用した。3、6、12および18ヵ月の時点でAFの発現している時間（AF burden）および累積のAF burdenは2群間で差を認めなかった。24ヵ月後に、アブレーション群では薬物治療群よりも有意にAF burdenが少なかった。高周波アブレーション群で22人（15%）がAFを有していたのに対し薬物治療群では43人（29%）であった。アブレーション群患者のうち10人（7%）が症候性AFを有していたのに対し薬物治療群では24人（16%）であった。最初にアブレーションで治療された患者のうち13人が追加で抗不整脈薬内服を必要とし、薬物治療で改善しなかった患者54人が追加で高周波アブレーションを施行された。
Full Text

In patients with atrial fibrillation (AF), radiofrequency ablation worked as well as or better than drugs to reduce paroxysmal AF, according to late-breaking research presented at the American Heart Association's Scientific Sessions 2011.

Anti-arrhythmic medications can control the heart rhythm and symptoms of atrial fibrillation (AF), but many patients don't respond well. Another option for stabilizing the heartbeat is delivering high frequency alternating current through a catheter to destroy the small bits of heart tissue that cause AF. In this case, researchers targeted tissue surrounding the pulmonary veins. This treatment option has not previously been tested for patients who haven't tried drug treatment.

Researchers randomized participants to either radiofrequency ablation (146) or an anti-arrhythmic drug (148). They assessed the patients at the study's start, and at 3, 6, 12, 18 and 24 months.

Each time, patients wore a portable heart monitor for seven days. Significant findings included:

  • At 3, 6, 12 and 18 months, there was no significant difference in the amount of time patients in the two groups experienced AF (AF burden) nor in the cumulative AF burden.
  • At 24 months, the ablation group did have significantly less AF burden than the drug-treated patients.
  • Twenty-two radiofrequency ablation patients (15 percent) had AF compared to 43 (29 percent) treated with drugs.
  • Ten ablation patients (7 percent) had symptomatic AF episodes compared to 24 (16 percent) in the drug group.

"Ablation therapy is at least as good and tends to be better than drug therapy at preventing episodes of atrial fibrillation," said Jens Cosedis Nielsen, M.D., lead researcher and professor of cardiology at Aarhus University Hospital in Denmark.

Of the patients primarily treated with ablation, 13 needed supplementary drugs and 54 patients who didn't improve with drugs underwent supplementary radiofrequency ablation.

"Not every patient should be offered ablation, but this research should be discussed with patients when a physician feels it is a viable treatment option," Nielsen said.

Co-authors are Arne Johannesen, M.D., D.M.Sci.; Pekka Raatikainen, M.D.; Gerhard Hindricks, M.D.; Hakan Walfridsson, M.D.; Ole Kongstad, M.D.; Steen Pehrson, M.D., D.M.Sci.; Anders Englund, M.D.; Juha Hartikainen, M.D.; Leif Spange Mortensen, M.S.; and Peter Steen Hansen, M.D., D.M.Sci.

Biosense Webster, Inc., and the Danish Heart Foundation funded the study.