Augmented Wide Area Circumferential Catheter Ablation for Reduction of Atrial Fibrillation Recurrence

Summary

Atrial fibrillation (AF) is an abnormal heart rhythm in which the top chambers of the heart beat very fast. AF catheter ablation is a known technique to convert heart rhythm from AF to normal rhythm. The technique sends out electrical energy through a catheter (long thin round solid tubes) to destroy the heart tissues in a focused area where AF is starting. This technique is practiced at many hospitals, including the Heart Institute, and is not experimental.

The AWARE study will compare two techniques of AF catheter ablation:

1. Ablation of tissues in wide circular bands around the opening of the pulmonary veins (bring blood back from lungs) in the left upper chamber of the heart. A medicine called adenosine will be given to unmask any incompletely ablated area. Additional ablations will be given if required. This is standard procedure.
2. Same as above but adenosine will not be used. Instead, additional ablation of a second circular band of tissues around the opening of the pulmonary veins will be given. This additional ablation is not standard procedure and is considered experimental.

The Investigators are testing if adding more ablation sites will help maintain normal heart rhythm and reduce the rate of return to AF. The study will compare the occurrence of medical events and complications between the two groups.

Identical supplies and equipment used in both techniques have been approved by Health Canada. Adenosine is currently approved by Health Canada for the treatment and diagnosis of arrhythmias.

396 participants from study sites across Canada will be randomly assigned "similar to flipping a coin" to treatment group 1 or group 2.

After the ablation, participants will have study follow-up at 3, 6 and 12 months. All participant's will be followed for a minimum of 12 months.

Conditions

• Atrial Fibrillation

Interventions

PROCEDURE

Wide area circumferential catheter ablation

All subjects in the control arm of the trial will undergo wide area circumferential catheter ablation (WACA; lesions delivered 1-2 cm away from the pulmonary vein ostium) around all four pulmonary veins to the endpoint of electrical isolation (demonstrated by entry and exit block using differential pacing). Catheter ablation will be performed using contact force (CF) and electroanatomical mapping system guidance (average CF \>10g, FTI \> 500 g-sec and minimum ablation duration \>10 sec). Dormant pulmonary vein conduction will be tested using adenosine, after completion of the lesion set, and additional lesions will be delivered to eliminate dormant PV conduction.

PROCEDURE

Augmented- wide area circumferential ablation procedure

Subjects in this group will have WACA performed as described for WACA. Following completion of the WACA procedure a second set of circumferential ablation lesions will be delivered around the first set of ablation lesions. The ablation catheter tip will be positioned at each of the ablation lesions along the first WACA line and then moved away (from the PV ostia) until healthy, non ablated tissue is recorded from the catheter tip. Energy will be delivered using CF and FTI data as described previously. Once the first WACA ablation line has been completely duplicated the procedure will be deemed complete. In case PV isolation is not achieved after the first WACA lesion set repeat electrophysiologic testing will be performed to determine whether the augmented-WACA procedure was successful in achieving PV isolation.

Sponsors & Collaborators

• Ottawa Heart Institute Research Corporation

  lead OTHER

Principal Investigators

• Girish Nair, MD · Ottawa Heart Institute Research Corporation

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2015-03-31

Primary Completion

2026-11-27

Completion

2026-11-27

Countries

• Canada

Study Locations