Abstract & Commentary
Should Catheter Ablation be First-Line Therapy for Patients with Paroxysmal AF?
By Edward P. Gerstenfeld, MD
Professor of Medicine, Chief, Cardiac Electrophysiology, University of California, San Francisco
Dr. Gerstenfeld does research for Biosense Webster, Medtronic, and Rhythmia Medical.
Source: Morillo CA, 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.
Atrial fibrillation (AF) is common and catheter ablation has become widely available.
According to the Heart Rhythm Society consensus statement,1 catheter ablation of AF should be considered after breaking through one antiarrhythmic drug (AAD). However, use of catheter ablation as first-line therapy is controversial. This multicenter, prospective study randomized patients with recent onset AF (≤ 4 episodes over prior 6 months) to either drug therapy or catheter between January 2006 and February 2012. The primary outcome was the occurrence of the first symptomatic or asymptomatic atrial tachyarrhythmia lasting > 30 seconds. One hundred twenty-seven patients were randomized to either antiarrhythmic therapy (n = 61) or radiofrequency catheter ablation ([RFCA], n = 66) and followed for up to 24 months. The most common AADs used were flecainide (50.9%) and propafenone (25%). Complete pulmonary vein isolation was achieved in 87% in the ablation group. AADs were all stopped at 90 days in the ablation arm, and anticoagulation with warfarin was continued for at least 3 months after ablation. The primary outcome was reached more often in the AAD group than the RFCA group (72.1% vs 54.5%; hazard ratio [HR], 0.56; 95% confidence interval [CI], 0.35-0.90). The first recurrence of symptomatic atrial tachyarrhythmia occurred in 59% in the drug group and 47% in the ablation group (HR, 0.56; 95% CI, 0.33-0.95; P = 0.03). There was a 9% incidence of serious adverse events in the ablation group, including four cases of cardiac tamponade. There were no deaths or strokes. There was a significant improvement in quality of life in both groups, with no significant difference. The authors concluded that among treatment-naive patients with paroxysmal AF, RFCA resulted in fewer recurrences of AF as compared to AAD, but recurrences were common in both groups.
Commentary
AF remains the most common arrhythmia and management of AF patients remains a significant part of many cardiology practices. Catheter ablation for AF has been increasingly accepted as a therapeutic option for AF, with the potential for AF "cure." However, while early single-center studies had dramatic success rates, multicenter trials have demonstrated 1-year AF freedom closer to 65%.2 Complications of AF ablation have also become more widely recognized and include stroke, pulmonary vein stenosis, left-atrial esophageal fistula, and cardiac tamponade. A recent nationwide insurance survey of patients undergoing AF ablation found a striking in-hospital mortality rate of 0.46%, with the majority occurring among low-volume operators (< 25 cases/year).3 A recent prospective, randomized study in the Netherlands found no difference in cumulative AF burden in the ablation vs drug arms, although the AF burden at 2 years was reduced in the ablation arm.4 In the Radiofrequency Ablation vs Antiarrhythmic drugs as first-line treatment of paroxysmal Atrial Fibrillation (RAAFT-2) study, there was a clear decrease in recurrent AF in the ablation group, although at 2 years there remained a 50% AF recurrence in the ablation group after a single ablation procedure. Of interest is that pulmonary vein isolation was achieved in only 87% of patients in the ablation arm, which is quite low. This occurred despite the fact that all the centers in the study were experienced in AF ablation.
So, should catheter ablation be first-line therapy for AF patients? There is little doubt that freedom from AF at 2 years is superior after catheter ablation compared to drug therapy. However, the complication rate in multicenter studies and general practice should not be overlooked. Also, pulmonary vein reconnection and the complexity of AF still leads to significant recurrence rates after a single procedure. Newer advances, such as contact force catheters and rotor-guided ablation, may improve single procedure success rates, but this remains to be tested prospectively. Therefore, at this time, I must agree that the current data support a trial of antiarrhythmic therapy in most patients with paroxysmal AF. However, some patients — often athletes or those already on multiple pharmaceutical agents — are interested in primary ablative therapy without a trial of AADs. I think the RAAFT-2 trial supports this approach as a reasonable option if the ablation is performed at an experienced center and the patient is informed of the anticipated risks and benefits of ablation.
REFERENCES
1. Calkins H, et al. 2012 HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of atrial fibrillation: Recommendations for patient selection, procedural techniques, patient management and follow-up, definitions, endpoints, and research trial design: A report of the Heart Rhythm Society (HRS) Task Force on Catheter and Surgical Ablation of Atrial Fibrillation. Heart Rhythm 2012;9:632-696.
2. Wilber DJ, et al. Comparison of antiarrhythmic drug therapy and radiofrequency catheter ablation in patients with paroxysmal atrial fibrillation: A randomized controlled trial. JAMA 2010;303:333-340.
3. Deshmukh A, et al. In-hospital complications associated with catheter ablation of atrial fibrillation in the United States between 2000 and 2010: Analysis of 93,801 procedures. Circulation 2013;128:2104-2112.
4. Jens Cosedis Nielsen, et al. Radiofrequency ablation as initial therapy in paroxysmal atrial fibrillation. N Engl J Med 2012;367:1587-1595.
