Jason G. Andrade, MD from Vancouver Costal Health and L’Institut de Cardiologie de Montréal discusses Cryoablation or Drug Therapy for Initial Treatment of Atrial Fibrillation.
Until catheter ablation is considered in patients with atrial fibrillation, guidelines prescribe a trial of one or more antiarrhythmic medicines. The first-line ablation, however, may be more effective in preserving sinus rhythm.
303 patients with symptomatic, paroxysmal, untreated atrial fibrillation were randomly assigned to undergo cryothermia balloon catheter ablation or receive antiarrhythmic drug therapy for initial rhythm regulation. To detect atrial tachyarrhythmia, all the patients obtained an implantable cardiac monitoring unit. The time for follow-up was 12 months. The first confirmed recurrence of any atrial tachyarrhythmia (atrial fibrillation, atrial flutter, or atrial tachycardia) between 91 and 365 days after catheter ablation or antiarrhythmic drug onset was the primary endpoint. Independence from symptomatic arrhythmia, the stress of atrial fibrillation and quality of life were the secondary endpoints.
At 1 year, 66 of 154 patients (42.9%) assigned to receive ablation, and 101 of 149 patients (67.8%) assigned to receive antiarrhythmic drugs (hazard ratio, 0.48; 95% confidence interval [CI], 0.35 to 0.66; P<0.001) had a recurrence of atrial tachyarrhythmia. In 11.0 percent of the patients who underwent ablation and in 26.2 percent of those who administered antiarrhythmic medications, symptomatic atrial tachyarrhythmia recurred (hazard ratio, 0.39; 95 percent CI, 0.22 to 0.68). The median percentage of atrial fibrillation duration was 0 percent with ablation (interquartile range, 0 to 0.08) and 0.13 percent with antiarrhythmic drugs (interquartile range, 0 to 1.60). Five patients (3.2 percent) who underwent ablation and six patients (4.0 percent) who received antiarrhythmic drugs reported severe adverse events.
There was a substantially lower rate of atrial fibrillation recurrence with catheter cryoballoon ablation in patients undergoing initial care for symptomatic, paroxysmal atrial fibrillation than with antiarrhythmic drug therapy, as measured by continuous cardiac rhythm monitoring. (Funded by Canada's Cardiac Arrhythmia Network and others; the number of EARLY-AF ClinicalTrials.gov, NCT0282597.)