Is cryoablation more effective than drug therapy to prevent recurrence of paroxysmal atrial fibrillation (AF)?
Initial cryoablation for patients with paroxysmal AF is superior to initial antiarrhythmic drug therapy. Another study in the same issue of New England Journal of Medicine (2021;384:316–324) compared cryoablation with medical therapy and had similar findings. (Level of Evidence = 1b)
The researchers identified 303 adults with paroxysmal AF and randomized them to receive initial therapy with cryoablation or an antiarrhythmic drug chosen by the treating physician (most commonly flecainide). Groups were balanced at baseline with a mean age of 58 years and a median duration of paroxysmal AF of one year. Patients were followed for one year. Patients recorded episodes of symptomatic AF and wore an implantable cardiac monitor to detect any episodes of tachyarrhythmia. Patients were able to cross over from medication to cryotherapy if an episode of tachyarrhythmia had occurred after the first 90 days, the episode warranted a change in therapy, and the patient was taking a therapeutic dose of the antiarrhythmic. This occurred in 24% of patients in the drug therapy group. Analysis was by intention to treat, and outcomes were assessed by a committee masked to treatment allocation. At one year, the likelihood of any episode of atrial tachyarrhythmia was lower in the ablation group (42.9% vs. 67.8%; hazard ratio = 0.48; 95% CI, 0.35 to 0.66; number needed to treat = 4). Symptomatic episodes were significantly less common in the ablation group (11.0% vs. 26.2%; hazard ratio = 0.39; 95% CI, 0.22 to 0.68; number needed to treat = 7). There was a slightly greater improvement in an AF-specific quality of life score (10-point difference at six months, 8 points at 12 months), but this is of borderline clinical significance on a 100-point scale. Serious adverse events were similar between groups, although hospitalizations were more common in the drug therapy group (13 vs. 5).
Study design: Randomized controlled trial (single-blinded)
Funding source: Government
Setting: Outpatient (any)
Reference: Andrade JG, Wells GA, Deyell MW, et al.; EARLY-AF Investigators. Cryoablation or drug therapy for initial treatment of atrial fibrillation. N Engl J Med. 2021;384(4):305–315.
Editor's Note: Dr. Ebell is deputy editor for evidence-based medicine for AFP and cofounder and editor-in-chief of Essential Evidence Plus, published by Wiley-Blackwell.