The STOP AF First Trial1,2 (NCT03118518) is a prospective, multicenter randomized study evaluating whether cryoballoon catheter ablation is superior to antiarrhythmic drug (AAD) therapy as a first-line rhythm control treatment in patients with symptomatic paroxysmal atrial fibrillation (PAF). A total of 225 drug-naïve patients (AAD for < 7 days) with symptomatic PAF aged 18–80 were enrolled at 24 centers in the United States. The Arctic Front Advance™ cryoballoon was used to establish pulmonary vein isolation (PVI) and the drug therapy arm received a class I or III AAD therapy.
Low Complication Rate
Primary safety events occurred in two subjects (estimated 12-month rate: 1.9%, 95% CI: 0.5–7.5%) in the cryoballoon arm. Since the upper bound of the 95% confidence interval was below the prespecified performance goal, the primary safety endpoint was met.
Freedom from Acute Procedural Failure or Atrial Arrhythmia Recurrence 12 Months Post-ablation
By modified intention-to-treat analysis (which included all randomized patients who initiated therapy), freedom from primary efficacy failure was:
A significant improvement (p < 0.01) in subjects’ quality of life was observed at 12 months for those in the ablation group as assessed with the AFEQT and EQ-5D questionnaires. Improvements in AF-specific quality of life at 12 months assessed using the AFEQT were larger with cryoballoon ablation versus AAD therapy.
Treatment success at 12 months
Treatment failure is defined as:
Composite of prespecified procedure- and system-related serious adverse events evaluated in the cryoballoon catheter ablation arm (prespecified performance goal: failure rate < 12%).
Primary safety events include:
Treatment arm only.
Wazni OM, Dandamudi G, Sood N, et al. Cryoballoon Ablation as Initial Therapy for Atrial Fibrillation. N Engl J Med. January 28, 2021;384(4):316-324.
Wazni OM, Dandamudi G, Sood N, et al. Cryoablation versus antiarrhythmic drug therapy as initial treatment for atrial fibrillation: impact on quality of life. J Am Coll Cardiol. 2021;77(18_Supplement_1):225-225.