"Catheter Ablation vs. Antiarrhythmic Drug Therapy for Atrial Fibrillation".The New England Journal of Medicine. 2020. [DOI and page number not provided].
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In patients with symptomatic, paroxysmal, untreated atrial fibrillation, is catheter cryoballoon ablation more effective than antiarrhythmic drug therapy in preventing the recurrence of atrial tachyarrhythmia?
Catheter cryoballoon ablation, as initial treatment, was more effective than antiarrhythmic drug therapy in reducing the recurrence of atrial tachyarrhythmia, as assessed by continuous cardiac rhythm monitoring, in patients with symptomatic, paroxysmal, untreated atrial fibrillation.
The EARLY-AF trial compared the efficacy of catheter ablation using a cryothermy balloon with antiarrhythmic drug therapy as initial treatment for preventing recurrence of symptomatic atrial fibrillation. Catheter ablation was associated with a significantly lower rate of atrial fibrillation recurrence, fewer symptomatic episodes, and a similar rate of serious adverse events when compared to treatment with antiarrhythmic medications.
Current guidelines typically recommend the use of antiarrhythmic drugs as initial therapy for rhythm control in symptomatic patients with atrial fibrillation.
- Multicenter, open-label, randomized trial with blinded end-point adjudication. - N=303 patients with symptomatic, paroxysmal, untreated atrial fibrillation. - Interventions: Catheter cryoballoon ablation (n=154) vs. antiarrhythmic drug therapy (n=149). - Follow-up: 12 months. - Primary end point: The first documented recurrence of any atrial tachyarrhythmia between day 91 and 365 post-intervention. - Secondary end points included freedom from symptomatic arrhythmia, the atrial fibrillation burden, and quality of life.
- Inclusion criteria: Adults >18 years with symptomatic atrial fibrillation and at least one episode detected on ECG within 24 months of randomization. - Exclusion criteria: History of regular use of a class I or class III antiarrhythmic drug at therapeutic doses. - Baseline characteristics were balanced across the two groups.
- Implantable cardiac monitoring device inserted in all patients to detect atrial tachyarrhythmia. - Catheter cryoballoon ablation targeting pulmonary vein isolation. - Antiarrhythmic drugs prescribed and adjusted to suppress atrial fibrillation.
- Primary efficacy end point reached in 42.9% in the ablation group vs. 67.8% in the antiarrhythmic drug group (hazard ratio [HR] 0.48; 95% CI, 0.35 to 0.66; P<0.001). - Recurrence of symptomatic atrial tachyarrhythmia: 11.0% with ablation vs. 26.2% with antiarrhythmic drugs (HR 0.39; CI, 0.22 to 0.68). - Median atrial fibrillation burden: 0% in the ablation group vs. 0.13% in the drug therapy group. - Serious adverse events occurred in 3.2% of the ablation group and 4.0% of the antiarrhythmic drug group.
- Crossover was restricted in the trial design, blunting the ability to detect a difference between groups had there been crossover. - Single ablation technology, which may limit the generalizability of results to other energy sources. - Follow-up was limited to one year, insufficient to determine the long-term impact of early ablation on disease progression and cost-effectiveness. - Cardiac monitors were implanted at the initiation of treatment, not at baseline, preventing assessment of the change in atrial fibrillation burden from baseline.
Trial was funded by the Cardiac Arrhythmia Network of Canada, unrestricted grants from Medtronic and Baylis Medical, and in-kind support from Medtronic and the University of British Columbia.
Authors' full text and supplementary materials available at NEJM.org.