Ablation vs Medication: Which First for Atrial Fibrillation and for Who?

April 14, 2014

A small study provides good evidence that radiofrequency ablation as first-line therapy has a lower failure rate vis a vis recurrence of AF when compared with antiarrhythmic therapy. But, there is more to this story.

Management options for persons with paroxysmal atrial fibrillation (PAF) include pharmacologic therapy and, as it gains populartiy, radiofrequency ablation (RFA). As clinical experience with RFA increases and the adverse effects associated with long-term use of advanced antiarrhythmic medications are better understood, the question of whether RFA can be used as first-line therapy has become the newest controversy in AF management. Most recently, the collapse of professional hockey player Rich Peverly, who has AF and was being managed with antiarrhythmic medications, added fuel to this debate. Peverly, it turns out, had been cardioverted just before the season opening, had considered ablation therapy, and had had his AF meds tritrated up just days before his collapse. Peverly's case has many proponents advocating RFA as first-line therapy in young, active patients who are otherwise healthy.

The Radiofrequency Ablation vs Antiarrhythmic Drugs as First-Line Treatment of Paroxysmal Atrial Fibrillation (RAAFT-2) study, recently published inJAMA, attempted to address this clinical question by randomizing 127 PAF patients who had not previously received treatment to receive either antiarrhythmic therapy (n=61) or ablation (n=66). Time to first symptomatic or asymptomatic atrial tachyarrhythmia (AF, atrial flutter or atrial tachycardia) lasting longer than 30 seconds as well as symptomatic recurrences and quality of life (QOL) at 24 months were assessed as the primary and secondary outcomes, respectively.

In this study, patients were young, healthy, and mostly free of heart disease. There were significantly more patients in the medication group (72%) than in the RFA group (52%) who had asymptomatic or symptomatic atrial tachyarrhythmia at 2 years (HR 0.56 in favor of RFA). The results were similar for the secondary outcomes (HR = 0.56 in favor of RFA). With respect to safety, there were no additional strokes or deaths in the procedural arm compared with the medication group; however, there were 4 cases of cardiac tamponade in the former group. Forty-three percent of patients (n=26) from the medication arm crossed over to the RFA arm at 1 year. At diagnosis, both groups had impaired QOL, but this improved over time with no difference between the randomized arms.

Small but significant

Although this study is small, it does provide good evidence that RFA ablation as first-line therapy has a lower failure rate with respect to recurrence of AF when compared with antiarrhythmic therapy (with the caveat that the overall failure rate is still greater than 50% in both groups). This study has been criticized, however, because the ablation strategy used may have been flawed. Furthermore, the rate of complications was not insignificant, including a 6% rate of cardiac tamponade. Finally, we only have follow-up data at 2 years. Since “AF begets AF,” it would be interesting to analyze longer-term (5 to 10 years) data to see whether this difference increases over time. 

As operators gain more experience over time, RFA is likely to become a safe and effective option for many relatively younger patients in whom AF is diagnosed. Current registry data show that high-volume operators have a relatively low rate of complications. When data on high- and low-volume operators were combined, however, an increase was seen in the rate of complications from 2000 to 2010 and the rate of in-hospital mortality was 0.42%.

For now, treatment should be individualized and ablation perfomred by high-volume operators at high-volume centers. Potentially, though, every patient with a new diagnosis of AF could be referred to an electrophysiologist for consultation to determine whether this would be an appropriate and safe alternative to a trial of antiarrhythmic medication.

References:

Morillo CA, Verma A, Connolly SJ, et al.  Radiofrequency ablation vs antiarrhythmic drugs as first-line treatment of paroxysmal atrial fibrillation. (RAAFT-2): A randomized trial. JAMA. 2014;311:692-700.