Clinical Studies and Outcomes Catheter Ablation for Atrial Fibrillation

Cryoballoon Ablation is Safe and Effective1

Results of the Sustained Treatment of Paroxysmal Atrial Fibrillation (STOP AF) Trial confirmed cryoballoon ablation is a safe and effective treatment for patients with symptomatic paroxysmal atrial fibrillation (PAF), for whom at least one antiarrhythmic drug has failed.

Study Design and Date 

First randomized, multicenter trial comparing antiarrhythmic drug therapy and cryoballoon ablation.

Designed to confirm the safety and effectiveness of the first-generation Arctic Front™ Cardiac Cryoablation System when used to treat patients with drug-refractory, recurrent symptomatic PAF.

Date: 2013

Number of Patients 

Enrolled 245 patients across 26 centers.

Key Findings

Results showed 69.9% of patients treated with Arctic Front were free from AFib at one year, compared to 7.3% of patients treated with drug therapy only.

The study also showed cryoballoon ablation is safe and provides statistically significant improvements in quality of life.

Primary Effectiveness Analysis
Treatment Success (n = 245)

  • 69.9% freedom from atrial fibrillation (AFib) at 12 months
  • 3.1% rate of cryoablation procedure events and 3.1% major AFib events in ablation arm
  • 19.0% (31/163) repeat ablation rate during the 90-day blanking period
Primary efficacy endpoint result for the STOP AF First clinical trial for paroxysmal atrial fibrillation

Outcomes of this trial led to FDA approval of cryoballoon ablation.



Packer DL, Kowal RC, Wheelan KR, et al. Cryoballoon ablation of pulmonary veins for paroxysmal atrial fibrillation: first results of the North American Arctic Front (STOP AF) pivotal trial. J Am Coll Cardiol. April 23, 2013;61(16):1713-1723.