Cryoballoon vs. Irrigated Radiofrequency Catheter Ablation: Double Short vs. Standard Exposure Duration (CIRCA-DOSE)

May 3, 2019 updated by: Jason Andrade, University of British Columbia

Cryoballoon vs. Irrigated Radiofrequency Catheter Ablation: The Effect of Double Short vs. Standard Exposure Cryoablation Duration During Pulmonary Vein Isolation.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and is associated with reductions in quality of life, functional status, cardiac performance, and overall survival.1 Catheter ablation, which is centered on electrical isolation of triggering foci within the pulmonary veins (PVI) through circumferential lesions around PV ostia, has been shown to result in sustained improvements in quality of life, decreased hospitalizations and, potentially, improved survival.2-4 PVI can be accomplished by percutaneous catheter-based thermo-coagulation (burning) with radiofrequency (RF) energy delivery or alternatively by thermo-cooling (freezing) with a cryoballoon catheter.5 Cryothermal ablation with a cryoballoon catheter offers an efficacious means to achieve PVI that is safer than the established technique. Although cryoballoon ablation has been used in clinical practice for sometime, the optimal duration of cryoballoon ablation has not been determined. Moreover, the biophysics of cryo-lesion formation suggests that repeated short freezes ("freeze-thaw-freeze" cycles) may be more efficacious in achieving deep homogenous lesion when compared to prolonged freezing durations. This grant proposal is to verify if repeated short freezing cycles are more efficacious (i.e., fewer recurrence of AF), and safer, than the established standard of long, single freeze cycles.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

348

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • British Columbia
      • Vancouver, British Columbia, Canada
        • Vancouver General Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

- Non-permanent atrial fibrillation documented on a 12 lead ECG, TTM or Holter monitor within the last 12 months Low Burden Paroxysmal - ≥2 episodes of AF over the past 12 months; Episodes terminate spontaneously within 7 days or via cardioversion within 48 hours of onset.

High Burden Paroxysmal - ≥4 episodes of AF over the past 6 months, with ≥2 episodes >6 hours in duration; Episodes terminate spontaneously within 7 days or via cardioversion within 48 hours of onset.

Early Persistent - ≥2 episodes of AF over the past 12 months; Episodes are successfully terminated via cardioversion within 7 days of onset.

  • Age of 18 years or older on the date of consent
  • Candidate for ablation based on AF that is symptomatic and refractory (ineffective or intolerant) to at least one class 1 or 3 antiarrhythmic
  • Continuous anticoagulation with warfarin (INR 2-3), low molecular weight heparin, or a novel oral antithrombotic (dabigatran, apixaban, rivaroxaban) for ≥4 weeks prior to the ablation; or a TEE that excludes LA thrombus ≤48 hours before ablation
  • Informed Consent Form

Exclusion Criteria:

  • Previous left atrial (LA) ablation or LA surgery
  • Pre-existing pulmonary vein stenosis or PV stent
  • Pre-existing hemidiaphragmatic paralysis
  • Contraindication to anticoagulation or radiocontrast materials
  • Anteroposterior LA diameter greater than 5.5 cm by TTE
  • Cardiac valve prosthesis
  • Clinically significant (moderately-severe, or severe) mitral valve regurgitation or stenosis
  • Myocardial infarction, PCI / PTCA, or coronary artery stenting during the 3-month period preceding the consent date
  • Cardiac surgery during the three-month interval preceding the consent date
  • Significant congenital heart defect (including atrial septal defects or PV abnormalities but not including PFO)
  • NYHA class III or IV congestive heart failure
  • Left ventricular ejection fraction (LVEF) less than 35%
  • Hypertrophic cardiomyopathy
  • Significant CKD (eGFR <30 mL/min/m2)
  • Uncontrolled hyperthyroidism
  • Cerebral ischemic event (strokes or TIAs) during the six-month interval preceding the consent date
  • Subject known to be pregnant
  • Life expectancy less than one (1) year
  • Currently participating or anticipated to participate in any other clinical trial of a drug, device or biologic during the duration of this study
  • Unwilling or unable to comply fully with study procedures and follow-up

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: TREATMENT
  • Allocation: RANDOMIZED
  • Interventional Model: PARALLEL
  • Masking: TRIPLE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
EXPERIMENTAL: Standard cryoablation
Patients randomized to the standard group will undergo cryoablation with target duration of 240 seconds. Once PVI is achieved a single "bonus" application of 240 seconds will be delivered after the rewarming phase (to +20oC).
Procedure: Pulmonary Vein Isolation
ACTIVE_COMPARATOR: Irrigated RF Ablation
Patients randomized to irrigated RF group will undergo standard wide circumferential PVI with an irrigated radiofrequency catheter
Procedure: Pulmonary Vein Isolation
EXPERIMENTAL: Short Cryoablation
Patients randomized to the multiple-freeze group will undergo cryoablation with target duration of 120 seconds. Once PVI is achieved a single "bonus" application of 120 seconds will be delivered after the rewarming phase (to +20oC).
Procedure: Pulmonary Vein Isolation

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Time to first recurrence of AF, atrial flutter, or left atrial tachycardia documented by 12-lead ECG, surface ECG rhythm strips, ambulatory ECG monitor, or implantable loop recorder and lasting 30 seconds or longer
Time Frame: 1 year
1 year

Secondary Outcome Measures

Outcome Measure
Time Frame
Time to first recurrence of symptomatic electrocardiographically documented AF/AFL/AT between days 91 and 365 after ablation
Time Frame: 1 year
1 year
Total arrhythmia burden (daily AF burden - hours/day; overall AF burden - % time in AF)
Time Frame: 1 year
1 year
Repeat ablation procedure because of documented recurrence of symptomatic AF/AFL/AT
Time Frame: 1 year
1 year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of British Columbia

Investigators

  • Principal Investigator: Jason Andrade, MD, University of British Columbia

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (ACTUAL)

September 1, 2014

Primary Completion (ACTUAL)

December 1, 2018

Study Completion (ACTUAL)

March 1, 2019

Study Registration Dates

First Submitted

July 30, 2013

First Submitted That Met QC Criteria

July 30, 2013

First Posted (ESTIMATE)

August 1, 2013

Study Record Updates

Last Update Posted (ACTUAL)

May 7, 2019

Last Update Submitted That Met QC Criteria

May 3, 2019

Last Verified

May 1, 2019

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • H13-01689

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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