Ventricular Tachycardia Ablation Through Radiation Therapy Consortium: Concept Description of an Observational Retrospective Multicentric Trial

Ventricular Tachycardia Ablation Through Radiation Therapy Consortium: Concept Description of an Observational Retrospective Multicentric Trial Via Matched Pair Analysis (VT-ARTr)

Recurrent ventricular tachycardia (VT) is a potentially life-threatening arrhythmia in patients with structural heart disease. Despite the use of antiarrhythmic drugs, implantable cardioverter-defibrillators (ICDs), and radiofrequency catheter ablation, VT recurrence rates remain high-reaching up to 66% in some series. For patients with refractory VT who are not candidates for further ablation or surgical interventions, there is a significant unmet need for novel, effective, and non-invasive treatment options.

Stereotactic body radiation therapy (SBRT) has recently emerged as a promising approach for treating ventricular arrhythmias through a technique known as stereotactic arrhythmia radioablation (STAR). Preliminary studies, including a phase I/II clinical trial, have demonstrated a substantial reduction in VT burden-up to 99.9%-following treatment, with an acceptable safety profile. Reported adverse events have included manageable pericardial effusion, radiation-induced pericarditis, and pneumonitis. The growing body of evidence supports STAR as a feasible and effective alternative for selected patients with treatment-resistant VT.

The objective of this study is to evaluate the efficacy and safety of stereotactic radiotherapy as a non-invasive ablation technique for the treatment of ventricular tachycardia (VT) in patients with refractory arrhythmias in whom conventional therapies have failed.

This is a retrospective observational study aimed at comparing outcomes between patients who received stereotactic radioablation and those who did not. A matched-pair analysis will be used to adjust for baseline clinical characteristics and ensure comparability between groups.

Inclusion Criteria:

• Diagnosis of refractory ventricular tachycardia (VT), as previously defined
• Age greater than 18 years
• Presence of an implantable cardioverter-defibrillator (ICD) for follow-up
• Not eligible for heart transplantation
• Estimated life expectancy of at least 1 year
• Ability to provide autonomous, informed consent to participate in the study

Exclusion Criteria:

• ICD interrogation demonstrating polymorphic VT
• Patients with INTERMACS class more than 4
• Patients with LVADs
• Patients with active neoplastic disease under oncological treatment