Surgical Ablation Works When Drug Therapy Fails for Atrial Fibrillation
A new study published in the January 27 issue of the Journal of the American Medical Association found surgical ablation works better than continued drug therapy when initial drug therapy fails to control paroxysmal atrial fibrillation (AF).
David J. Wilber, MD and colleagues used a prospective, multicenter, randomized study to compare catheter ablation with antiarrhythmic drug therapy (ADT) in patients with symptomatic AF who had not improved with at least one drug. Their primary goal was to evaluate freedom from symptomatic AF recurrence following treatment, but they also evaluated total atrial arrhythmia recurrence during follow-up.
Between October 2004, and October 2007, 167 patients were enrolled in the study, and randomly assigned 2:1 to ablation (106 patients) or a previously unused antiarrhythmic drug (61 patients). The last follow-up was performed on January 19, 2009. Five patients from the ADT group and 3 patients from the catheter ablation group did not complete the assigned treatment. Most of those randomized to the drug therapy arm of the study were treated with either flecainide (Tambocor) or propafenone (Rythmol).
The researchers found catheter ablation succeeded in preventing recurrence of symptomatic fibrillation in 70% of patients compared to only 19% of patients on drug therapy.
Major treatment-related adverse events within the first 30 days occurred in 8.8% of patients treated with drugs and 4.9% of those treated with catheter ablation.
The American Heart Association states that atrial fibrillation affects 2.2 million Americans. AF is an irregular heart rhythm which originates in the heart's two small upper chambers (the atria). Blood isn't pumped completely out of them, so it may pool and clot. This clot formation puts the patient at increased risk of strokes. It is estimated that about 15% of strokes occur in people with atrial fibrillation.
Antiarrhythmic drugs are the usual first-line therapy, but are inconsistently effective. Approximately half of all patients will have a recurrence of fibrillation within six months to a year. ADT have a range of adverse events associated with the medications ranging from nuisance effects, such as dizziness, to more serious consequences, such as inflammation of the liver, lung, or thyroid.
Wilber DJ, et al "Comparison of Antiarrhythmic Drug Therapy and Radiofrequency Catheter Ablation in Patients with Paroxysmal Atrial Fibrillation: A randomized controlled trial" JAMA 2010; 303(4): 333-40.