Ventricular Tachycardia, Monomorphic

The objective of this clinical study is to evaluate the safety and effectiveness of the Adagio Medical vCLAS Ventricular Ablation System (including VTS Catheter and Console) in the ablation treatment of Sustained Monomorphic Ventricular Tachycardia (SMVT)

Ventricular tachycardia (VT) is a dangerous fast heart rhythm originating from scarred areas of the heart muscle, often after a heart attack or in patients with cardiomyopathy. Patients with VT and structural heart disease typically receive an implantable cardioverter-defibrillator (ICD) to prevent sudden death. Despite the ICD, recurrent VT and ICD shocks remain common and are associated with poor quality of life. Current preventive therapies - antiarrhythmic medications and catheter radiofrequency ablation - have important limitations including side effects, incomplete effectiveness, and procedural risk. Stereotactic Arrhythmia Radioablation (STAR) is a non-invasive treatment in which a single, precisely targeted dose of radiation is delivered to the scar tissue that gives rise to the abnormal heart rhythm. STAR has previously been studied in patients who have failed catheter ablation or are too high risk for that procedure, with promising results. However, STAR has not been formally evaluated as a first-line treatment. This single-arm prospective feasibility study will enroll 20 adults with structural heart disease and sustained monomorphic VT. Each participant will receive a single 25 Gy fraction of stereotactic body radiotherapy (VMAT technique) targeted at the arrhythmogenic substrate identified by cardiac imaging, 12-lead ECG, and (where available) non-invasive electrocardiographic mapping or electroanatomical mapping. Participants will be followed at 6 weeks, 3, 6, 9, and 12 months to assess the primary efficacy outcomes (death, appropriate ICD shock, VT storm, and sustained VT below ICD detection rate after a 6-week blanking period) and safety outcomes (acute heart failure decompensation, drop in left ventricular ejection fraction, and STAR-specific toxicities such as pneumonitis, esophagitis, and pericarditis). The hypothesis is that STAR delivered as first-line therapy is safe and effective, with a comparable toxicity and efficacy profile to catheter radiofrequency ablation.

Cardiac radioablation is a new treatment for ventricular tachycardia (VT), which uses beams of radiation to treat heart scar that causes VT. To identify the scar areas, magnetic resonance imaging (MRI) and computed tomography (CT) imaging are often used. These are both types of medical imaging that allow clinicians to examine scar area without having to do invasive surgery. Researchers have developed new heart imaging protocols using both MRI and CT. Their MRI protocol method can now spot both dense and scattered scar tissue. The CT protocol combines multiple different types of scans into a single appointment and uses a special scanner that captures the motion of the heart. For this study, patients will undergo CT and MRI imaging according to these new imaging protocols. With this study, researchers aim to show that these new imaging protocols can be undergone by patients with ventricular tachycardia and can be used to identify scar. Researchers will also use these scans to make radiation treatment plans to identify which types of treatment can be delivered safely to patients.

The aim of the study is to compare the efficacy and safety of treating recurrent sustained Ventricular Tachycardia (sVT) after prior Catheter Ablation (CA) in patients with Implanted Cardioverter-Defibrillator (ICD) between re-do of conventional endocardial CA and Stereotactic Arrhythmia Radioablation (STAR).