Recruiting

SBRT

Sponsor:

John Sapp

Code:

NCT04162171

Conditions

Ventricular Tachycardia

Myocardial Infarction

Heart Disease Structural Disorder

Eligibility Criteria

Sex: All

Age: 0+

Healthy Volunteers: Not accepted

Interventions

Stereotactic Body Radiotherapy (SBRT) ablation of VT

Study Details

Brief summary:

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.

Conditions

Ventricular Tachycardia

Myocardial Infarction

Heart Disease Structural Disorder

Study ID

NCT04162171

Start date

Jun 1, 2021

Status verified date

Mar, 2026

Completion date

Sep 1, 2027

Anticipated

Primary completion date

Jun 1, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 0+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • 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.

Exclusion Criteria:

  • 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)
  • Pregnancy
  • Active ischemia (acute thrombus diagnosed by coronary angiography, or dynamic ST segment changes demonstrated on ECG) or another reversible cause of VT (e.g. drug-induced arrhythmia), had recent acute coronary syndrome within 30 days thought to be due to acute coronary arterial thrombosis, or have CCS functional class IV angina. Note that biomarker level elevation alone after ventricular arrhythmias does not denote acute coronary syndrome or active ischemia.

Study Design

Enrollment

12 participants

Anticipated

Intervention Model

Single group

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Imaging & SBRT Treatment for Ventricular Tachycardia

Interventions

Stereotactic Body Radiotherapy (SBRT) ablation of VT

Additional 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.

Primary outcome measure

  • Comparative analysis of ventricular arrhythmia events [ Time Frame: During the first 6 months post blanking period vs. 6 months prior to treatment. ]
  • Comparative analysis of targeting methods assessed by volume of sparred healthy tissue [ Time Frame: From time of enrollment to 7.5 ,months post treatment. ]

Central Contacts and Locations

Central contacts

Karen Giddens

902 237-5551karen.giddensl@nshealth.ca

John Sapp, MD FRCPC

902.473.4474John.Sapp@nshealth.ca

Locations

Nova Scotia Health Authority

Recruiting

Halifax, Nova Scotia, Canada, B3H 3A7

Contacts

Gillian Schraefel, RN

902 473 7733Gillian.Schraefel@nshealth.ca

Principal Investigator:

John L Sapp, MD FRCPC

More Information

Sponsor

John Sapp

Last update posted

Mar 18, 2026

Last verified

Mar, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by John Sapp on 2026-03-18.