RAAFT-2 favors ablation over drugs but highlights risks

Radiofrequency ablation appears to have a leg up on standard therapy for treating patients with paroxysmal atrial fibrillation (AF), based on results of the RAAFT-2 trial published in the Feb. 19 issue of JAMA. But both treatments had a high recurrence rate and ablation was far from risk-free.

RAAFT-2 (Radiofrequency Ablation vs Antiarrhythmic Drugs for Atrial Fibrillation Treatment) is a multicenter randomized controlled clinical trial that compared radiofrequency ablation with antiarrhythmic drugs in patients with paroxysmal AF who had no previous antiarrhythmic medication treatment. It was designed as a superiority trial, with a primary efficacy outcome of a documented first recurrence of symptomatic AF, atrial flutter or tachycardia of 30 seconds or more.

Carlos A. Morillo, MD, of the Population Health Research Institute at McMaster University in Hamilton, Canada, and colleagues enrolled 127 treatment-naïve AF patients with at least one episode documented six months before randomization between July 2006 and January 2010. Follow-ups occurred at one, six, 12 and 24 months after randomization.

Patients received transtelephonic monitoring systems and were instructed to record and transmit every experienced symptomatic episode as well as send biweekly recordings.

Of the 61 patients in the standard care group, 72.1 percent had a recurrence of any kind of atrial tachyarrhythmia lasting 30 seconds or more compared with 54.5 percent of the 66 patients in the ablation group. RAAFT-2 researchers also observed asymptomatic AF in 18 percent of the standard care group vs. 9 percent of the ablation group.

The ablation group had a lower rate of recurrence of symptomatic AF, atrial flutter or tachycardia compared with standard care (47 percent vs. 59 percent) and recurrence of symptomatic AF (41 percent vs. 57 percent). Fourteen percent of patients in the ablation group had a repeat procedure. Both groups reported improvement in their quality of life after treatment.

There were no strokes or deaths in either group. But the ablation group had a higher percentage of serious adverse events, at 9 percent vs. 5 percent for the group treated with antiarrhythmic drugs.

“These findings highlight the fact that although ablation is effective, there are still approximately 50% of patients who have AF recurrences 24 months after undergoing a single procedure,” Morillo and colleagues wrote. “Ablation extends the time free of both symptomatic and asymptomatic AF and significantly reduced the recurrence of repeated episodes, potentially having an effect on AF progression.”

The authors noted that they found a higher rate of serious complications with ablation than had previously been reported, which underscores the procedure poses risks that should be communicated to patients.

In an accompanying editorial, Hugh Calkins, MD, of Johns Hopkins Hospital in Baltimore, added the finding was unexpected, given that operators in the trial were highly skilled and the patient population was relatively healthy. He described the results as “a powerful endorsement” of guideline recommendations on the use of ablation for patients with paroxysmal AF treated with at least one antiarrhythmic drug that failed and in those in whom drugs had not failed.