Radiofrequency Ablation as Initial Therapy in Paroxysmal Atrial Fibrillation
How does radiofrequency catheter ablation (RFCA) compare to antiarrhythmic drugs for initial therapy of paroxysmal (AF)?
In the MANTRA-PAF (Medical Antiarrhythmic Treatment or Radiofrequency Ablation in Paroxysmal Atrial Fibrillation) trial, 294 patients (mean age 55 years) with symptomatic paroxysmal AF and no prior rhythm-control therapy were randomly assigned to RFCA (n = 146) or treatment with a class IC or class III antiarrhythmic drug (n = 148). The RFCA strategy was encirclement of the pulmonary veins, a left atrial roof line, and optional ablation lines at the mitral and/or cavotricuspid isthmus. A 7-day Holter monitor was performed at 3, 6, 12, 18, and 24 months. The primary endpoint was AF burden.
The RFCA group underwent a mean of 1.6 procedures. In the drug group, 36% of patients underwent RFCA because of drug failures. There were no significant differences between the two groups in cumulative AF burden or in AF burden at 3, 6, 12, or 18 months. At 24 months, the AF burden was significantly lower in the RFCA group (90th percentile 9% vs. 18%). One death in the RFCA group was caused by procedure-related stroke.
The cumulative AF burden during 2 years of follow-up is not significantly lower when RFCA is used as first-line therapy compared to antiarrhythmic drug therapy.
In a much smaller prior randomized study, recurrent AF occurred significantly less often during 1 year of follow-up in the RFCA group than in the drug group. However, the goal of antiarrhythmic drug therapy is to reduce the AF burden, not to completely prevent AF. This study, which very appropriately used AF burden as the study endpoint, validates the recommendation that RFCA be reserved for patients who do not respond adequately to drug therapy.
Keywords: Stroke, Catheter Ablation
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