October 24th, 2012
Atrial Fibrillation: Radiofrequency Catheter Ablation and Antiarrhythmic Drug Therapy Compared
A trial comparing radiofrequency catheter ablation (RFA) to antiarrhythmic drug therapy (AAD) as initial therapy for paroxysmal atrial fibrillation (AF) found no difference in the overall burden of AF between the groups. But the trial also turned up evidence supporting the use of RFA as an initial treatment strategy in some patients.
In a paper published in the New England Journal of Medicine, European investigators report on 294 patients with paroxysmal AF with no previous use of AADs who were randomized in the MANTRA-PAF (Medical Antiarrhythmic Treatment or Radiofrequency Ablation in Paroxysmal Atrial Fibrillation) trial. Patients — age 70 years and younger and with no other major heart disease — were healthier than the general AF population.
The investigators found no significant differences in the cumulative burden of AF or the burden at 3, 6, 12, or 18 months. However, at 2 years, the AF burden was significantly reduced in the RFA group compared with the AAD group (90th percentile of AF burden: 9% vs. 18%, p=0.007). In addition, the percentage of patients with no AF and no symptomatic AF was higher in the RFA group than in the AAD group (85% vs. 71%, p=0.004; 93% vs. 84%, p=0.01, respectively). In the RFA group, there were three cases of cardiac tamponade in addition to one death after a procedure-related stroke. In the AAD group, 36% of the patients received supplementary RFA.
The overall results, write the authors, “support the current guidelines recommending antiarrhythmic drugs as first-line treatment in most patients with paroxysmal atrial fibrillation.” However, the positive findings for RFA, as well as the high number of crossovers from AAD to RFA, suggest that “a substantial minority of patients” treated with AAD “may eventually require ablation for adequate rhythm control.”
In an accompanying editorial, William Stevenson and Christine Albert mention the “substantial procedural risks” associated with RFA and warn that the results should not be extrapolated to different patient populations, since the MANTRA-PAF population was younger and healthier than the general AF population. They express hope that the much larger CABANA (Catheter Ablation versus Anti-arrhythmic Drug Therapy for Atrial Fibrillation) trial will provide more definitive evidence about RFA. RFA, they conclude, is “a reasonable option for patients with symptomatic paroxysmal atrial fibrillation before therapy with an antiarrhythmic drug.”