NEJM study shows Catheter Ablation better than Drug Therapy for Atrial Fibrillation
A study published in the New England Journal of Medicine showed that patients receiving initial treatment for symptomatic, paroxysmal atrial fibrillation, with catheter cryoballoon ablation saw a significantly lower rate of atrial fibrillation recurrence than those who received antiarrhythmic drug therapy.
Atrial fibrillation is the most common cardiac arrhythmia that affects approximately 1 to 2% of the overall population. Studies show that without preventative treatment, atrial fibrillation can recur in 90% of patients.
Guidelines recommend the use of antiarrhythmic drugs initially for the maintenance of sinus rhythm in symptomatic patients. However, these medications have been shown to have limited efficacy along with substantial side effects.
Catheter ablation is superior to antiarrhythmic drugs in maintaining sinus rhythm and improving quality of life in patients in whom drugs have failed to be efficacious. However, catheter ablation as the first-line treatment may be a better alternative to antiarrhythmic drugs in preventing the recurrence of atrial tachyarrhythmia and reducing the atrial fibrillation burden.
This investigator-initiated, multicenter, open-label, randomized trial with blinded endpoint adjudication was conducted across 18 centers in Canada. Data monitoring, collection, and primary data analysis were performed by the Cardiovascular Research Methods Centre (University of Ottawa) and the steering committee.
The trial was funded by a peer-reviewed grant from the Cardiac Arrhythmia Network of Canada. The trial enrolled 303 adults (>18 years of age) who had symptomatic atrial fibrillation and had experienced at least one episode of atrial fibrillation, detected on electrocardiography within 24 months before randomization. Eligible patients were randomly assigned in a 1:1 ratio to an initial strategy of catheter cryoballoon ablation or antiarrhythmic drug therapy.
All the patients received an implantable cardiac monitoring device to detect atrial tachyarrhythmia.
The primary endpoint was the first documented recurrence of any atrial tachyarrhythmia (atrial fibrillation, atrial flutter, or atrial tachycardia) between 91 and 365 days after catheter ablation or the initiation of an antiarrhythmic drug.
The secondary endpoints included freedom from symptomatic arrhythmia, the atrial fibrillation burden, and quality of life.
The study saw that at 1 year, a recurrence of atrial tachyarrhythmia had occurred in 66 of 154 patients (42.9%) assigned to undergo ablation and in 101 of 149 patients (67.8%) assigned to receive antiarrhythmic drugs.
Symptomatic atrial tachyarrhythmia had recurred in 11.0% of the patients who underwent ablation and in 26.2% of those who received antiarrhythmic drugs.
The median percentage of time in atrial fibrillation was 0% with ablation and 0.13% with antiarrhythmic drugs. Serious adverse events occurred in 5 patients (3.2%) who underwent ablation and in 6 patients (4.0%) who received antiarrhythmic drugs.
Therefore, the trial concluded that patients with untreated paroxysmal atrial fibrillation showed a significantly lower rate of recurrence of atrial tachyarrhythmia, as assessed by continuous cardiac rhythm monitoring with catheter cryoballoon ablation than with antiarrhythmic drug therapy.