SBRT for Ventricular Arrhythmia

Stereotactic Antiarrhythmic Radiotherapy for Ventricular Arrhythmia in Austria (Austrian STAR)

The aim of this study is to demonstrate the safety and efficacy of STAR (Stereotactic Antiarrhythmic Radiotherapy) in patients with VT (ventricular tachycardia) who are unresponsive to standard treatments. Additionally, the planned study aims to provide further insights into the effects of STAR on VT burden, ICD interventions, and insights regarding late toxicities, particularly those related to the heart, which are currently not well understood.

Inclusion Criteria:

• Recurrent VTs/VES with significant burden despite guideline-directed therapy
• Existing protective ICD (Implantable cardioverter-defibrillator) implantation except in the presence of contraindications
• AND lack of response or intolerance to antiarrhythmic medication
• AND status post ≥1 catheter ablation due to monomorphic VT(s) and VT early recurrence (<12 months after the last catheter ablation) OR contraindication for endocardial ablation (mechanical valve prosthesis, LV (left ventricular) thrombus, or lack of vascular access in suspicion of endocardial substrate)
• MINIMAL VT BURDEN: The patient must have had at least 3 VT episodes (sustained VT, ICD-ATP, or ICD shock) in the last 3 months prior to study enrollment.
• Presence of suitability for radiation therapy with respect to SBRT
• Age ≥ 18 years
• Existing informed consent

Exclusion Criteria:

• Acute myocardial infarction or percutaneous coronary intervention or heart surgery (<3 months before study enrollment)
• Status post intra-thoracic pre-radiation
• Immediate proximity to radiosensitive structures (e.g., esophagus) making therapy unsafe to administer
• Advanced symptomatic heart failure (NYHA Class IV)
• Polymorphic VT or ventricular fibrillation (confirmed in 12-lead ECG and/or ICD interrogation)
• Extensive myocardial scar substrate that would result in too large of a radiation volume
• Life expectancy < 6 months considering all comorbidities and in the Seattle Heart Failure Model
• Presence of a Left Ventricular Assist Device (LVAD)
• Use of cytotoxic medications
• Pregnancy or lactation - negative pregnancy test within 14 days before study entry required for women of childbearing potential