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A Clinical Study of the Arctic Front Cryoablation Balloon for the Treatment of Paroxysmal Atrial Fibrillation

Phase 3
Completed
Conditions
Paroxysmal Atrial Fibrillation
Interventions
Device: Arctic Front® Cryoablation Catheter
Registration Number
NCT00523978
Lead Sponsor
Medtronic Cardiac Rhythm and Heart Failure
Brief Summary

This study (STOP AF) is a prospective, randomized, controlled, multicenter, pivotal clinical investigation conducted at 26 investigational sites in the United States and Canada. Subjects with paroxysmal atrial fibrillation (PAF) referred for ablative intervention after efficacy failure of one or more Study Atrial Fibrillation (AF) Drugs (flecainide, propafenone or sotalol) were randomized 2:1 to cryoablation intervention (Experimental Subjects, ES) or to a Study AF Drug (Control Subjects, CS). Subjects were followed for 12 months with scheduled and symptom-driven assessments to detect recurrent atrial fibrillation by means of periodic electrocardiograms, weekly scheduled trans-telephonic monitoring, patient-initiated trans-telephonic monitoring, and 24-hour Holter monitoring at 6 and 12 months. The first 90 days after study therapy was initiated was considered a blanked period for all subjects.

Detailed Description

STOP AF (PS-023) is a randomized, controlled study of subjects 18 to 75 years old who had been referred for ablative intervention after failing one or two (but not all three) anti-arrhythmic drugs used in the treatment of AF (flecainide, propafenone and sotalol). Study subjects were randomized into two arms: the cryoablation (treatment) arm and the membrane-active antiarrhythmic drug (control) arm. A 90- day blanked follow-up period, including reablation and medication adjustments was applied in both arms to optimize therapies. All subjects underwent follow-up assessments at 1, 3, 6, 9 and 12 months, weekly transtelephonic monitoring, 24-hour Holter monitoring and CT/MRI of the pulmonary veins(at 6 and 12 months) during the trial period. Control subjects who were confirmed to be chronic treatment failures were permitted to crossover to cryoablation in this trial.

Acute procedural success was defined for subjects that underwent cryoablation and demonstrated electrical isolation in ≥ 3 Pulmonary Veins (PVs) at the conclusion of the first protocol-defined cryoablation procedure using the Arctic Front® Cardiac CryoAblation Catheter System.

The primary effectiveness endpoint was defined as having acute procedural success and freedom from chronic treatment failure (CTF) for experimental subjects, and freedom from CTF for control subjects. Freedom from (CTF) was defined for both groups as the occurrence of detectable AF during a non-blanked follow-up period, or an AF Intervention, or the use of a non-study AF drug at any time.

The co-primary safety outcome measures were Cryoablation Procedure Events (CPEs) in cryoablated subjects and Major Atrial Fibrillation Events (MAFEs) in both groups. CPEs were device- or procedure-related serious adverse events.

Other safety assessments were made during the course of the STOP AF trial specific to pulmonary vein stenosis (PVS) and phrenic nerve injury.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
245
Inclusion Criteria
  • Documented Paroxysmal Atrial Fibrillation (PAF): PAF diagnosis, 2 episodes of PAF within the last 2 months, at least 1 episode of PAF must be documented
  • Age 18-75
  • Documented Effectiveness Failure of one (1) AF drug
  • Willing to be randomized to either group and do full 12 month follow-up
  • Able to follow standardized AF drug protocol
Exclusion Criteria
  • Any cardioversion within 3 months or more than 2 within 2 years
  • Amiodarone within 6 months
  • LA size > 5.0cm
  • Previous LA ablation/surgery, structural heart disease, heart failure class III or IV
  • Hypertrophic cardiomyopathy, Mitral prosthesis
  • Unstable angina, uncontrolled hyperthyroidism
  • Stroke or TIA within 6 months, MI within 2 months, cardiac surgery within 3 months
  • Thrombocytosis, thrombocytopenia
  • Any condition contraindicating chronic anticoagulation
  • EF <40%
  • Pregnancy
  • Life expectancy <1year

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
ControlFlecainide or Sotalol or PropafenoneControl Subjects were treated with an AF Drug (flecainide, propafenone, or sotalol) that they had not previously failed.
ExperimentalArctic Front® Cryoablation CatheterExperimental subjects received cryoablation intended to isolate the pulmonary veins and ablate arrhythmia foci. If necessary, experimental subjects were allowed a previously failed Study Atrial Fibrillation Drug (AF Drug).
Primary Outcome Measures
NameTimeMethod
Acute Procedural Success (APS)371.4 Minutes (Average)

Acute Procedural Success was defined as a demonstration of electrical isolation in ≥ 3 Pulmonary Veins (PVs) at the conclusion of the first protocol-defined cryoablation procedure. APS was decided at the end of the procedure the mean time was calculated for the time frame.

Treatment Success12 months

Treatment Success was defined as Acute Procedure Success (APS) and freedom from Chronic Treatment Failure (CTF) for Experimental Subjects, and freedom from CTF for Control Subjects. Under this pre-specified definition of Treatment Success, Experimental Subjects must have had APS and remained free of CTF during the 12-month follow-up duration, while Control Subjects must have remained free of CTF during the 12-month follow-up duration.

Freedom From Chronic Treatment Failure (CTF)12 month follow up period

Subjects that did not have or were free of CTF. CTF was defined as the occurence of an Atrial Fibrillation (AF) intervention, use of non-study AF drug therapy, or the occurence of detectable AF which is is defined as an episode of AF, documented in a tracing, and lasting more than 30 seconds, occurring during a Non Blanked Follow-up Period.

Freedom From Major Atrial Fibrillation Events (MAFEs)12 Months

Subjects that did not have or were free of MAFEs. MAFEs were serious adverse events categorized as cardiovascular death, myocardial infarction, stroke, or hospitalization for AF recurrence/ablation, flutter ablation, embolic events, heart failure, hemorrhage or anti-arrhythmic drug treatment.

Cryoablation Procedure Events (CPEs)To end of ablation procedure

Subjects that had CPEs. CPEs were device- or procedure-related serious adverse events (SAE) categorized as access site complications, cardiac damage, pulmonary vein (PV) stenosis, embolic complications, arrhythmias, unresolved phrenic nerve palsy and death.

Secondary Outcome Measures
NameTimeMethod

Trial Locations

Locations (26)

University of Alabama

🇺🇸

Birmingham, Alabama, United States

Cedar Sinai Medical Center

🇺🇸

Los Angeles, California, United States

Emery Crawford Long Hospital

🇺🇸

Atlanta, Georgia, United States

Piedmont Hospital

🇺🇸

Atlanta, Georgia, United States

Iowa Heart Center

🇺🇸

Des Moines, Iowa, United States

Baylor Heart and Vascular Hospital

🇺🇸

Dallas, Texas, United States

Inova Research Center

🇺🇸

Falls Church, Virginia, United States

Medical College of Virginia

🇺🇸

Richmond, Virginia, United States

Sentara CV Research Institute

🇺🇸

Norfolk, Virginia, United States

UC Davis Medical Center

🇺🇸

Sacramento, California, United States

Mayo Clinic- Jacksonville

🇺🇸

Jacksonville, Florida, United States

University of Pennsylvania Health

🇺🇸

Philadelphia, Pennsylvania, United States

Massachusetts General Hospital

🇺🇸

Boston, Massachusetts, United States

Cleveland Clinic Foundation

🇺🇸

Cleveland, Ohio, United States

Cardiology Associates of Green Bay

🇺🇸

Green Bay, Wisconsin, United States

Arrhythmia Center of Southern WI

🇺🇸

Milwaukee, Wisconsin, United States

Colorado Cardiac Alliance -- Memorial Hospital

🇺🇸

Colorado Springs, Colorado, United States

Mayo Clinic

🇺🇸

Rochester, Minnesota, United States

Laval Hospital

🇨🇦

Ste-Foy, Quebec, Canada

Banner Good Samaritan Medical Center

🇺🇸

Phoenix, Arizona, United States

Montreal Heart Institute

🇨🇦

Montreal, Quebec, Canada

BayHeart Group -- St-Joseph's Hospital

🇺🇸

Tampa, Florida, United States

Stanford Hospital

🇺🇸

Stanford, California, United States

New Mexico Heart Institute

🇺🇸

Albuquerque, New Mexico, United States

London Medical Health Sciences

🇨🇦

London, Ontario, Canada

Montefiore Medical Center

🇺🇸

Bronx, New York, United States

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