Cardiac ablation and mapping
STOP AF First trial
This study evaluates the safety and effectiveness of the Medtronic Arctic Front™ cryoablation system as an initial first-line rhythm control treatment.
Study purpose and design
The STOP AF First trial1,2 is a prospective, multicenter, randomized study evaluating whether Arctic Front™ cryoballoon 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.
Key findings
Effective
74.6% 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:
74.6% in the cryoballoon arm, 45.0% in the AAD arm (p < 0.001)
Safe
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.
Quality-of-life outcomes
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 atrial fibrillation-specific quality of life at 12 months assessed using the AFEQT were larger with Arctic Front™ cryoballoon ablation versus AAD therapy.
Meta-analysis
A meta-analysis of three randomized controlled trials demonstrates cryoballoon ablation, compared to AADs, as an initial first-line therapy is associated with incremental benefits, including:
- 39% relative reduction in the risk of atrial arrhythmia recurrence3
- 8.32 points larger improvement in AFEQT score on average3
- 29% relative reduction in healthcare utilization3
- 62% relative reduction in hospitalization3
No significant difference in the rate of serious adverse events.
Watch the scientific exchange video.
Learn more about the impact of Arctic Front™ cryoballoon ablation as initial treatment for atrial fibrillation featuring a discussion on a state-of-the-art review and meta-analysis demonstrating incremental benefits of Arctic Front™ cryoablation compared to AADs.
- Jason Andrade, M.D.
- Hugh Calkins, M.D.
- Andrea Russo, M.D.
- Jaret Tyler, M.D.
Endpoint definitions
Primary efficacy endpoint
Treatment success at 12 months
Treatment failure is defined as:
- Acute procedural failure*
- Any subsequent AF surgery or ablation in the left atrium (including those performed during the blanking period)
- Any of the following after the 90-day blanking period:
- Documented AF/AT/AFL
- Cardioversion
- Class I or III AAD use*
Primary safety endpoint
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:
- Within 7 days:
- Transient ischemic attack
- Stroke
- Major bleeding
- Myocardial infarction
- Vascular complication
- Within 30 days:
- Significant pericardial effusion
- Within 12 months:
- Symptomatic pulmonary vein stenosis
- Atrial-esophageal fistula
- Unresolved phrenic nerve injury at 12 months
Study population
Key inclusion criteria
- A diagnosis of symptomatic PAF with the following documentation:
- Physician’s note indicating recurrent self-terminating AF or PAF
- Any ECG-documented AF within 6 months prior to enrollment
- Age 18–80
Key exclusion criteria
- History of AF treatment with class I or III AAD, including sotalol, with the intention to prevent an AF recurrence. However, patients pretreated with above AAD for less than 7 days with the intention to convert an AF episode were allowed.
- Prior left atrial ablation or left atrial surgical procedure
- Prior persistent AF (continuous AF > 7 days)
- Left atrial diameter > 5.0 cm
- NYHA class III or IV congestive heart failure and/or known left ventricular ejection fraction (LVEF) less than 45%
Study recurrence monitoring
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3 months |
6 months |
12 months |
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| Patient-activated ambulatory ECG (TTM; weekly and when symptomatic | ➜ |
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| 12-lead ECG |
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| 24-hour continuous ambulatory ECG |
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Contact us
Educational resources on
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Access detailed product information, including spec sheets, videos, and presentations.
*
Treatment arm only.
References
1
Wazni OM, Dandamudi G, Sood N, et al. Cryoballoon ablation as initial therapy for atrial fibrillation. N Engl J Med. 2021;384(4):316–324.
2
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.
3
Andrade JG, Wazni OM, Kuniss M, et al. Cryoballoon Ablation as Initial Treatment for Atrial Fibrillation: JACC State-of-the-Art Review. J Am Coll Cardiol. August 31, 2021;78(9):914–930.