A Phase 3 interventional study of Arctic Front® Cryoablation Catheter and Flecainide or Sotalol or Propafenone in Paroxysmal Atrial Fibrillation, sponsored by Medtronic Cardiac Rhythm and Heart Failure. Completed at 26 sites in 2 countries. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2018-10-16.
Sponsored by Medtronic Cardiac Rhythm and Heart Failure · Phase 3, Interventional, and Treatment
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.
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.
3,870 studies on the registry are indexed under Atrial Fibrillation; 924 are open to participants now.
This study's enrollment of 245 is above the median of 144 across 2,380 interventional studies indexed under Atrial Fibrillation.
Browse Atrial Fibrillation studies →Medtronic Cardiac Rhythm and Heart Failure is the lead sponsor of 239 studies on the registry; 6 are open to participants now.
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Exclusion Criteria:
Experimental 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).
Device: Arctic Front® Cryoablation Catheter
Control Subjects were treated with an AF Drug (flecainide, propafenone, or sotalol) that they had not previously failed.
Drug: Flecainide or Sotalol or Propafenone
Experimental Subjects received cryoablation intended to isolate the pulmonary veins and ablate arrhythmia foci with the cryoablation catheter system.
Also known as: Arctic Front® Cardiac CryoAblation Catheter System, Artic Front®
Flecainide 200 mg / day Propafenone 450 mg / day Propafenone-SR 650 mg / day Sotalol 240 mg / day
Also known as: Tambocor, Sotalol, Propafenone
Acute Procedural Success (APS)
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.
Time frame: 371.4 Minutes (Average)
Freedom From Chronic Treatment Failure (CTF)
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.
Time frame: 12 month follow up period
Treatment Success
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.
Time frame: 12 months
Freedom From Major Atrial Fibrillation Events (MAFEs)
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.
Time frame: 12 Months
Cryoablation Procedure Events (CPEs)
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.
Time frame: To end of ablation procedure
Investigators at 26 sites in the United States and Canada, enrolled and randomized a total of 245 study subjects, during the 21 months trial period, between 10 October 2006 and 30 June 2008.
| Milestone | Cryoablation | Standard Treatment With Drugs Only |
|---|---|---|
| Started | 171 | 87 |
| Completed | 162 | 79 |
| Not completed | 9 | 8 |
| Withdrew: Withdrawal by subject | 3 | 7 |
| Withdrew: Screen failures | 5 | 1 |
| Withdrew: Death | 1 | 0 |
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.
| participants | Cryoablation |
|---|---|
| Acute Procedural Success (APS) | 160 |
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.
| participants | Cryoablation | Standard Treatment With Drugs Only |
|---|---|---|
| Freedom From Chronic Treatment Failure (CTF) | 117 | 6 |
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.
| participants | Cryoablation | Standard Treatment With Drugs Only |
|---|---|---|
| Treatment Success | 114 (62.3 to 76.9) | 6 (2.7 to 15.2) |
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.
| participants | Cryoablation | Standard Treatment With Drugs Only |
|---|---|---|
| Freedom From Major Atrial Fibrillation Events (MAFEs) | 158 | 75 |
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.
| participants | Cryoablation |
|---|---|
| Cryoablation Procedure Events (CPEs) | 5 |
Collected over All pharmacologic and ablative treatments and arrhythmic disease adverse events on study subjects were followed through 12 months of follow-up.. Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Cryoablation | — | 20/163 (12.3%) | 19/163 (11.7%) |
| Standard Treatment With Drugs Only | — | 12/82 (14.6%) | 16/65 (24.6%) |
| Event | Cryoablation | Standard Treatment With Drugs Only |
|---|---|---|
| PneumoniaRespiratory, thoracic and mediastinal disorders | 3/163 | 0/82 |
| Worsening AFCardiac disorders | 2/163 | 1/82 |
| A fib persistent-drug loadCardiac disorders | 0/163 | 1/82 |
| Acute renal failure requiring dialysisRenal and urinary disorders | 0/163 | 1/82 |
| Altered mental status S/P cardiac arrestPsychiatric disorders | 0/163 | 1/82 |
| AppendicitisGastrointestinal disorders | 0/163 | 1/82 |
| Atrial FibrillationCardiac disorders | 0/163 | 1/82 |
| Atrial flutter-recurrentCardiac disorders | 0/163 | 1/82 |
| Cardiac tamponadeCardiac disorders | 0/163 | 1/82 |
| Cardiopulmonary arrest with resuscitationCardiac disorders | 0/163 | 1/82 |
| Event | Cryoablation | Standard Treatment With Drugs Only |
|---|---|---|
| Atrial FibrillationCardiac disorders | 14/163 | 16/65 |
| HeadacheNervous system disorders | 17/163 | 11/65 |
| Atrial FlutterCardiac disorders | 18/163 | 10/65 |
| FatigueGeneral disorders | 12/163 | 9/65 |
| DizzinessNervous system disorders | 15/163 | 9/65 |
| NauseaGastrointestinal disorders | 9/163 | 9/65 |
| Chest DiscomfortGeneral disorders | 4/163 | 8/65 |
| CoughRespiratory, thoracic and mediastinal disorders | 19/163 | 7/65 |
| DyspnoeaRespiratory, thoracic and mediastinal disorders | 7/163 | 7/65 |
| HypotensionVascular disorders | 3/163 | 5/65 |
| Age, Continuous(years) | Cryoablation | Standard Treatment With Drugs Only | Total |
|---|---|---|---|
| Mean | 56.7 ± 0.73 | 56.4 ± 1.04 | 56.6 ± 0.6 |
| Sex: Female, Male(Participants) | Cryoablation | Standard Treatment With Drugs Only | Total |
|---|---|---|---|
| Female | 38 | 18 | 56 |
| Male | 125 | 64 | 189 |
| Region of Enrollment(participants) | Cryoablation | Standard Treatment With Drugs Only | Total |
|---|---|---|---|
| United States | 123 | 63 | 186 |
| Canada | 40 | 19 | 59 |
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Medtronic Cardiac Rhythm and Heart Failure