The EARLY-AF Trial: Catheter cryoballoon ablation for atrial fibrillation [Classics Series]

1. This study found that in patients with paroxysmal atrial fibrillation (AF), patients who received ablation were less likely to experience atrial tachyarrhythmia compared to those who received antiarrhythmic drugs (42.9% vs. 67.8%).

2. No significant differences in adverse events were seen between groups.

Original Date of Publication: January 2021

This study summary is an excerpt from the book 2 Minute Medicine’s The Classics in Medicine: Summaries of the Landmark Trials, 2e (The Classics Series).

Study Rundown: The Early Aggressive Invasive Intervention for Atrial Fibrillation (EARLY-AF) trial compared catheter cryoballoon ablation to antiarrhythmic drug therapy in patients with symptomatic paroxysmal AF. The ablation group had significantly lower rates of both asymptomatic and symptomatic tachyarrhythmia as compared to those administered antiarrhythmic medications. The main limitation of the EARLY-AF trial was that it did not have the sample size to evaluate cardiovascular outcomes. Although, the primary endpoint of atrial tachyarrhythmia reoccurrence is a significant indicator of recovery from AF. In summary, the EARLY-AF trial demonstrated that individuals who receive catheter cryoballoon ablation following symptomatic paroxysmal AF have lower recurrence of atrial tachyarrhythmia as compared to those who receive antiarrhythmic drugs.

Please click to read study in NEJM

In-Depth [randomized controlled trial]: In the EARLY-AF trial, patients with symptomatic paroxysmal AF detected on electrocardiography within 24 months of baseline were randomized to either receive antiarrhythmic drug therapy (n = 149) or catheter cryoballoon ablation (n = 154). Although the trial was open-label, end-point adjudication was blinded and conducted by an end-point committee to minimize bias. The primary endpoint of recurrence of atrial tachyarrhythmia 30 seconds or longer was measured by implantable cardiac monitor and occurred less frequently in the ablation group (HR 0.48; 95%CI 0.35-0.66). Symptomatic atrial tachyarrhythmia was also significantly lower in the ablation group (HR 0.39; 95%CI 0.22-0.68). Conversely, serious adverse events did not differ significantly between groups.

Andrade JG, Wells GA, Deyell MW, Bennett M, Essebag V, Champagne J, et al. Cryoablation or Drug Therapy for Initial Treatment of Atrial Fibrillation. New England Journal of Medicine. 2021 Jan 28;384(4):305–15.

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