Cohort Study - SBRT for VT Radioablation
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
AgeNot listed
SponsorJohn Sapp
About this trial
Ventricular tachycardia (VT) contributes to over 350,000 sudden deaths each year in the US. Malignant VTs involve an electrical "short circuit" in the heart, formed by narrow channels of surviving tissue inside myocardial scar. Current treatment for VT consists of either implantable defibrillators (ICDs), suppressive drug therapy, catheter ablation or a combination of all 3.
Implantable Defibrillators (ICDs) reduce sudden death and can terminate some ventricular tachycardia (VT) without shocks, but they don't prevent VT. The occurrence of ≥1 ICD shock is associated with reductions in mental well-being and physical functioning, and increases in anxiety and sometimes depression. Further, ICD shocks have been consistently associated with adverse outcomes, including heart failure and death. Furthermore, the most important predictor of ICD shocks is a history of prior ICD shocks.
Therapies to suppress VT include antiarrhythmic drug therapy and catheter ablation, neither however is universally effective. When VT recurs despite antiarrhythmic drug therapy and catheter ablation, novel yet invasive, approaches may be required. Such invasive procedures carry consequent risks of cardiac and extra-cardiac injury.
Stereotactic body radiotherapy (SBRT) is a non-invasive technique that delivers high doses of radiation precisely to specified regions in the body, while minimizing exposure to adjacent tissue. This technique is currently, and commonly used in the treatment of cancer. Conventional application of SBRT has made use of its ability to spare non-target tissue, including for treatment of tumors near the heart. More recently, clinicians have changed the paradigm, by focusing radioablative energy on ventricular scar responsible for ventricular tachycardia. Pre-clinical studies have supported the concept and were followed by first-in-human VT therapeutic experience in 2017. Subsequent studies have had encouraging results for patients who failed or were unable to tolerate conventional treatment.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Structural heart disease: ischemic or non-ischemic cardiomyopathy diagnosed with cardiac imaging demonstrating either segmental myocardial dysfunction, or presence of scar, AND
One of the following monomorphic VT events despite prior attempted catheter ablation (or contraindication for ablation), AND despite treatment with a class III antiarrhythmic drug (contraindicated, ineffective or not tolerated): A: Documented sustained monomorphic VT terminated by pharmacologic means, DC cardioversion or manual ICD Therapy. B: ≥3 episodes of monomorphic VT treated with antitachycardia pacing (ATP), at least one of which was symptomatic C: ≥ 5 episodes of monomorphic VT treated with antitachycardia pacing (ATP) regardless of symptoms D: ≥1 appropriate ICD shocks, E: ≥3 monomorphic VT episodes within 24 hours ** VT events must be confirmed by ECG/monitor or ICD download.
Disqualifiers
Unable or unwilling to provide informed consent
Have received prior radiotherapy to the likely treatment field
Inotrope-dependent heart failure or an anticipated life-expectancy of < 1 year in the absence of VT
Presenting arrhythmia: polymorphic VT or ventricular fibrillation (VF)
Trial design
Design model
Single group
Treatments tested in this trial
Stereotactic Body Radiotherapy (SBRT) ablation of VT
RadiationAdditional imaging for SBRT planning and implementation: * Planning CT (pCT) - CT simulator that utilizes a respiratory positioning monitoring (RPM) optical tracking system and SBRT immobilization setup to provide necessary data to allow for monitoring of the patient's deep inspiration breath-hold (DIGH) maneuver during treatment delivery. * SBRT treatment - 30 min procedure on a TrueBeam 1 linear accelerator using SBRT fixation. Patient alignment and DIBH maneuver from the pCT will be replicated using the on-board cone-beam CT (CBCT) guidance and RPM systems.
Treatment groups
12 Participants
are divided into 1 treatment groupGroup A: Imaging & SBRT Treatment for Ventricular TachycardiaExperimental treatment 1 intervention
Trial outcomes
Primary outcomes
1
Comparative analysis of ventricular arrhythmia events
Number of patients with a reduction in the absolute number of ventricular arrhythmia events following ablation and blanking period, in comparison with those prior to treatment.
Time frame
During the first 6 months post blanking period vs. 6 months prior to treatment.2
Comparative analysis of targeting methods assessed by volume of sparred healthy tissue
Effectiveness of different myocardial substrate targeting methods on sparing non-target tissue. Delivered treatment approach as compared to a proposed calculated treatment plan using a single phase of the 4DcCT. Measured differences between 2 target-method volumes will equate to the volume of sparred tissue.
Time frame
From time of enrollment to 7.5 ,months post treatment.Secondary outcomes
1
Number of patients with procedural complications, including: all cause mortality, pericarditis, pneumonitis, heart failure hospitalization and extra-cardiac injury
Composite of; all cause mortality, pericarditis, pneumonitis, heart failure hospitalization and extra-cardiac injury.
Time frame
Through study completion,min of 7.5 months to max of 2 years.2
Time to Recurrent Arrhythmia Outcomes
Composite of; appropriate ICD shock, VT storm, incessant VT, sustained VT below ICD detection and appropriate antitachycardia pacing.
Time frame
Through study completion,min of 7.5 months to max of 2 years3
Ventricular arrhythmia Burden
Composite of; number of appropriate shocks, number of inappropriate shocks, number of antitachycardia pacing events.
Time frame
During 6 months prior vs. 6 months following treatment.Sponsors and contacts
Click on the lead sponsor to view all of their trials.
John Sapp
Lead sponsor
Nova Scotia Health Authority
Sponsor institution
Source ClinicalTrials.gov