MANTRA-PAF: RF ablation superior to drugs in paroxysmal AF
MedWire News: Patients with paroxysmal atrial fibrillation (AF) who receive radiofrequency (RF) ablation have significantly lower AF burden - but not cumulative AF burden - at 24 months, compared with patients treated with anti-arrhythmic drugs (AAD), research shows.
Patients who underwent RF ablation also had significantly better quality of life (QoL) at 12 and 24 months than those given AAD, the researchers reported at the American Heart Association Annual Scientific Sessions in Orlando, Florida.
The randomized controlled multicenter Medical Anti-arrhythmic Treatment or Radiofrequency Ablation in Paroxysmal Atrial Fibrillation (MANTRA-PAF) trial pitted RF ablation against standard AAD in relatively young patients. The primary endpoints were cumulative AF burden (percentage of time spent in AF) during 35-day Holter monitoring, and AF burden during each 7-day Holter monitoring.
"We think that these data support radiofrequency ablation as a first-line treatment in patients with paroxysmal atrial fibrillation. However, these were selected patients, they were relatively young, without much comorbidity, and these data cannot be extrapolated to elderly patients with more comorbidities. This study should not be taken as an argument for offering all patients with atrial fibrillation radiofrequency ablation," said lead investigator, Jens Cosedis Nielsen (Aarhus University Hospital, Denmark).
The MANTRA-PAF trial is the first large randomized, multicenter study comparing the efficacy of RF ablation with optimized AAD as first-line therapy for preventing relapse within 24 months of symptomatic and/or asymptomatic paroxysmal AF in treatment-naïve patients.
Patients were followed with 7-day Holter monitor recordings at 3, 6, 12, 18, and 24 months. The primary endpoints were the cumulative burden of AF during 35 days of follow-up, and AF burden at each 7-day Holter recording. The secondary endpoints were any AF and symptomatic AF at 24 months, burden of symptomatic AF at each follow-up interval, atrial flutter, QoL at 12 and 24 months as measured by the Short-Form 36 (SF-36) QoL scale, and serious adverse events.
Of the 294 patients randomized, 146 patients (mean age=56 years) were assigned to RF ablation (140 patients underwent the procedure, and 69 of these patients had repeat ablations), and 148 patients (mean age=54 years) were assigned to AAD (mean=1.24 drugs).
"For every follow-up, atrial fibrillation burden was significantly lower than at baseline, so both treatments were effective. There was no difference in atrial fibrillation burden at baseline or at 3 and 6 months. At 12 and 18 months, there was trend toward lower atrial fibrillation burden in the ablation groups, and after 2 years this was highly significant," Nielsen said.
The mean rank for AF burden at 24 months was 138 among patients who underwent ablation versus 157 among those assigned to AAD (p=0.007).
There was no significant difference in cumulative AF burden, however. The groups had similar QoL scores at baseline, and both experienced significant improvement from baseline. In the SF-36 physical component summary, but not the mental component summary, QoL scores were significantly higher in those patients who had undergone ablation than those who received AAD, at 50 versus 48, respectively (p=0.02).
There were three deaths in the ablation group and four deaths in the drug group. One patient in the ablation group had a stroke during the procedure. There were no significant differences in adverse events between the two groups.
William Stevenson (Brigham and Women's Hospital, Boston, Massachusetts, USA), the invited discussant, said that the MANTRA-PAF trial data support a statement in the European guidelines for the management of AF, which stated that "considering… the relative safety of the technique when performed by experienced operators, ablation may be considered as an initial therapy in selected patients."
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By Neil Osterweil