An interventional study of Conventional Bronchial Thermoplasty and Image Guided Bronchial Thermoplasty in Asthma, sponsored by Dr. Grace Parraga. Completed at 2 sites in Canada. Open to participants aged 18 Years to 60 Years. Per ClinicalTrials.gov, last updated 2023-05-12.
Sponsored by Dr. Grace Parraga · Not applicable, Interventional, and Treatment
Patients in London and Hamilton with severe asthma who are deemed eligible by a respirologist to undergo bronchial thermoplasty treatment will be randomized to image-guided or conventional bronchial thermoplasty using hyperpolarized noble gas imaging.
This is a one year, single centre randomized controlled trial. Subjects will be identified through the London Asthma Centre located at St. Joseph's Hospital and from Hamilton at St. Joseph's Healthcare, and will be given a letter of information for the study. The study will only recruit subjects with asthma who are undergoing BT as part of their normal clinical care and asthma treatment plan. Those interested will sign the consent form at the clinic.
Bronchial thermoplasty (BT) is a novel FDA approved outpatient asthma treatment procedure which aims to "cure" symptoms by permanently reducing airway smooth muscle mass in the lobar and segmental bronchi. Under local anesthetic, radiofrequency energy is delivered to warm the airway wall to 65 degrees celcius. The effect of this procedure is a reduction in airway smooth muscle mass in the treated airways resulting in a reduced potential for bronchoconstriction.
Fourteen asthma patients will be enrolled in the study and each subject will visit the centre on five occasions (three pre-treatment visits and two post-treatment visits). We will evaluate pre-therapy optimization using inflammometry, pre-therapy ventilation defect reproducibility and BT treatment effects (pre-treatment visit 1= 5±2 days pre-optimization, pre-treatment visit 2 = 15±7 days pre-BT, pre-treatment visit 3 = 5±2 days pre-BT, post-treatment visit 4=6 weeks post-BT, post treatment visit 5 = 6 months post-BT). At pre-treatment visit 1, patients will be randomized to image-guided or conventional therapy. For all subjects, at all visits, spirometry, plethysmography and 3He and/or 129Xe MRI will be performed. Methacholine challenge (MCh) will be performed (for those subjects with FEV1 >60%) at pre-treatment visit 3 and post-treatment visit 4 with spirometry and MRI performed pre- and post-MCh. Pre-treatment visit 3 will include a low-dose thoracic CT that will be used to generate a detailed 3D model of the airway tree. MRI will be co-registered to the CT with 3D airway rendering to enable spatial comparisons between ventilation defects and airways.
All subjects will also complete bi-weekly and weekly quality of life questionnaires. Self-reported data will be uploaded by each subject monthly to our website using a confidential and password protected upload.
MRI of the lungs will be performed using an inhaled contrast agent: either Hyperpolarized Helium-3 or Hyperpolarized Xenon-129. Participants will inhale the hyperpolarized gas and perform a breathhold for up to 16 seconds. Two different types of images will be acquired in the coronal plain during each visit: 1) 1H thoracic cavity, and 2) 3He and/or 129Xe static ventilation. Respiration and oxygen saturation will be monitored throughout the imaging session.
3,921 studies on the registry are indexed under Asthma; 507 are open to participants now.
This study's enrollment of 25 is below the median of 83 across 2,752 interventional studies indexed under Asthma.
Browse Asthma studies →Dr. Grace Parraga is the lead sponsor of 8 studies on the registry; 4 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Male and female aged 18-60 years of age with a clinical diagnosis of asthma, as per:
Subject has asthma and is taking regular maintenance medication for the past 12 months that includes:
Exclusion Criteria:
At pre-treatment Visit 3, imaging data will be acquired to generate a patient-specific bronchial thermoplasty treatment plan which will include 15-20 target airways, prioritized in order of importance and grouped by lobe, to be targeted during a single session BT treatment procedure. Airways demonstrating dynamic or static bronchoconstriction will be targeted for BT treatment based on their spacial proximity to ventilation defects.
Procedure: Image Guided Bronchial Thermoplasty
Patients in this group will undergo conventional 3 stage bronchial thermoplasty (during 3 separate bronchoscopies).
Procedure: Conventional Bronchial Thermoplasty
Conventional bronchial thermoplasty is performed during three bronchoscopy sessions each separated by approximately three weeks.
Patient-specific bronchial thermoplasty based on imaging data will be performed during one bronchoscopy session.
Whole lung and lobe specific ventilation defect percent (VDP) as measured by 3He or 129Xe
Change in VDP post BT
Time frame: 48 +/- 2 weeks post bronchial thermoplasty treatment
Pulmonary function measurements
Change in pulmonary function post BT
Time frame: 48 +/- 2 weeks post bronchial thermoplasty
Quality of Life questionnaires
Change in subject reported QOL post BT
Time frame: 48 +/- 2 weeks post bronchial thermoplasty
Dyspnea Scales
Dyspnea scale score post BT
Time frame: 48 +/- 2 weeks post bronchial thermoplasty
This study is completed, as verified in May 2023. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Dr. Grace Parraga