This will play a video. - Multiple Medtronic Cryoablation catheters on a blue background

Stop Persistent AF Clinical trial1

This prospective, multicenter, single-arm clinical trial assessed the safety and efficacy of pulmonary vein isolation (PVI) with Medtronic cryoballoon for treating drug-refractory, symptomatic, persistent atrial fibrillation (AF).

Purpose and design

The STOP Persistent AF trial is the first and largest, prospective, multicenter, single-arm study with prespecified performance goals to assess the safety and efficacy of PVI using the Medtronic Arctic Front Advance™ Cryoballoon for patients with drug-refractory, symptomatic, persistent AF. The trial included 165 patients treated at 25 sites across the United States, Canada, and Japan.

Key findings

0.6% shown in light blue text on a white background

Primary safety endpoint met

Primary safety endpoint rate of 0.6% was below prespecified performance goal (P = 0.002). Only one primary safety event occurred and was unrelated to study device.

54.8% shown in navy blue text on a white background

Primary effectiveness endpoint met

Primary efficacy endpoint of 54.8% exceeded prespecified performance goal (P < 0.001).

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Efficiency outcomes

Short and predictable procedure times of 121 ± 46 minutes

Quality-of-life outcomes

Secondary endpoint assessments of quality of life demonstrated significant improvements by 12 months post-ablation (P < 0.001) with a high rate of freedom from repeat ablation (86.8%).

A quality of life graph from the STOP Persistent AF Clinical trial that shows that study patients mental and physical health was improved compared to the baseline of patients prior to receiving a cryoablation
A quality of life graph from the STOP Persistent AF Clinical trial that shows that study patients atrial fibrillation symptoms were greatly reduced after receiving a cryoablation


Primary efficacy endpoint 

Success at 12 months > 40% performance goal

  • Acute procedural success (cryoballoon PVI only)
  • Freedom from AF/AT/AFL ≥ 30 sec after 90-day blanking
  • No Class I or III AAD dose initiation/increase after blanking

Primary safety endpoint

Safety event rate < 13% performance goal

  • Within 7 days: death, transient ischemic attack, cerebrovascular accident, major bleeding that requires transfusion, myocardial infarction, cardiac perforation, tamponade, or pericardial effusion
  • Within 12 months: PV stenosis or AE fistula
  • At 12 months: unresolved PNI

Quality-of-life secondary endpoint

  • AFEQT and SF-12 (physical and mental) at baseline, 6 months, and 12 months
Medtronic Cryoballoon on a blue background

Patient inclusion criteria

Key inclusion criteria

  • Symptomatic persistent AF defined as a continuous, sustained episode lasting longer than 7 days but ≤ 6 months
  • Failure or intolerance of at least one AAD
  • At least 18 years of age

A doctor crossing his arms and smiling

Key exclusion criteria

  • Prior left atrial ablation or surgery 
  • Stroke/transient ischemic attack within 6 months of enrollment
  • Left ventricular ejection fraction ≤ 35%
  • Left atrial diameter > 5.0 cm

Recurrence monitoring

A recurrence monitoing chart for the STOP Persistent AF Clinical Trial that shows the various monitoring devices and follow up duration in weeks and months



Su WW, Reddy VY, Bhasin K, et al. Cryoballoon Ablation of Pulmonary Veins for Persistent Atrial Fibrillation: Results From the Multicenter STOP Persistent AF Trial. Heart Rhythm. Published online June 23, 2020.