Patients with paroxysmal atrial fibrillation (AF) treated with catheter ablation first line showed significantly better improvement than those treated initially with drug therapy in a multicentre, randomised, unblinded trial. The Medical ANtiarrhythmic Treatment or Radiofrequency Ablation in Paroxysmal Atrial Fibrillation (MANTRA-PAF) trial compared radiofrequency catheter ablation with antiarrhythmic drug therapy as first-line treatment for paroxysmal AF.

The initial trial included patients with at least two episodes of symptomatic AF within the preceding six months but with no episode lasting longer than seven days (without spontaneous termination or cardioversion).

After baseline Holter recording, patients were randomly allocated to an initial strategy of either ablation or treatment with class IC or class III antiarrhythmic drugs.

The endpoint of ablation was taken as the elimination of high frequency electrical activity inside the pulmonary veins. The primary efficacy endpoint was AF burden in seven-day Holter recordings during follow-up.

This particular study was a five-year follow-up of the original trial and included assessment of any AF and symptomatic AF burden by one seven-day Holter recording and quality of life assessment using physical and mental component scores on the SF-36 questionnaire.

A total of 245 of the 294 patients (83%) attended the five-year follow-up, 125 of those randomised to ablation and 120 randomised to drug therapy. Holter recording results were available in 227 cases, 116 in the ablation group and 111 in the drug therapy group.

Significantly more patients in the ablation group, compared with the drug therapy group, were free from any AF: 126/146 (86%) vs 105/148 (71%), P = 0.001, relative risk (RR) 0.82 (95% CI: 0.73-0.93).

Likewise, significantly more patients in the former group were free from symptomatic AF: 137/146 (94%) vs 126/148 (85%), P = 0.015, RR 0.91(95% CI: 0.84-0.98).

AF burden was significantly lower in the ablation group (any AF: P = 0.003; symptomatic AF: P = 0.02).

Improvements in quality of life seen in both groups after two years persisted after five years but scores did not differ between the groups.

Radiofrequency catheter ablation is an effective treatment for patients with paroxysmal AF who have failed a trial of antiarrhythmic drug therapy. However, it has not been clear if we should be offering ablation earlier rather than an initial trial of antiarrhythmic drug therapy.

The authors conclude: ‘The results of this five-year follow-up indicate that radiofrequency ablation is superior to antiarrhythmic drug therapy as initial treatment for symptomatic paroxysmal AF, with respect to long-term suppression of AF.’

This study supports the notion of offering catheter ablation earlier to patients with paroxysmal AF if the aim is to reduce the occurrence and burden of AF although patients felt better regardless of which treatment was offered.

Dr Peter Savill

Nielsen JC, Johannessen A, Raatikainen P et al for the MANTRA-PAF Investigators, Long-term efficacy of catheter ablation as first-line therapy for paroxysmal atrial fibrillation: 5-year outcome in a randomised clinical trial. Heart 2017;103:368-76