An interventional study of Stereotactic Arrhythmia Radioablation (STAR) and Catheter Ablation in Ventricular Tachycardia, Monomorphic, Ventricular Tachycardia, Sustained and Ventricular Tachycardia (VT), sponsored by Medical University of Silesia. Not yet recruiting at 1 site in Poland. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-06-12.
Sponsored by Medical University of Silesia · Not applicable, Interventional, and Treatment
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).
Study Objectives:
To evaluate the safety and efficacy of Stereotactic Arrhythmia Radioablation (STAR) as a second-line therapy for sustained Ventricular Tachycardia (sVT) in optimally treated patients following endocardial Catheter Ablation (CA).
Study Design:
This study is a single-center randomized, noninferiority, head-to-head control trial comparing the efficacy and safety of two ablation methods for recurrent sVT after failing CA.
Patient Population:
Optimally treated patients aged ≥18 with Implantable Cardioverter-Defibrillators (ICD) in the primary or secondary prevention of sudden cardiac death (SCD), who have undergone endocardial CA and are candidates for re-ablation of recurrent symptomatic ventricular tachycardia (VT) following the 2022 European Society of Cardiology Guidelines for the management of patients with ventricular arrhythmias and the prevention of SCD.
The planned size of the group is 150.
The planned recruitment period is 42 months, and the observation period is 18 months.
Patients will be randomly assigned to experimental and control groups for a 1:1 group size ratio. The block randomized stratification method will be used with a central randomization system. Sex and left ventricular ejection fraction (≤40% vs. >40%) will be stratifying factors.
Intervention:
The intervention under investigation (experimental) will be STAR ablation. The standard intervention will be repeated endocardial radiofrequency CA. The target area for sVT ablation will be the arrhythmogenic substrate, defined by electrophysiological study (EPS) with three-dimensional electroanatomical mapping (obligatory in the standard therapy arm, optional in the STAR arm) and imaging tests (i.e., MSCT/CMR/PET-CT). The following will be integrated using dedicated computer software: 1) anatomical data-locating the arrhythmogenic scar area with channels of heterogeneous tissue-obtained using MSCT, CMR, PET-CT/SPECT, 2) three-dimensional electroanatomical maps-locating electrograms showing low peak-to-peak voltage, local abnormal ventricular activities, the sequence of myocardial activation, and critical isthmus sites for re-entrant VT, and 3) electrocardiograms detected during sinus rhythm and ventricular pacing during EPS. In the experimental arm, the obtained data will become the basis for STAR planning by a team consisting of a diagnostic cardiologist, radiologist, electrophysiologist, and radiotherapist. The obtained data will become the basis for endocardial CA planning in the control arm.
Observation:
Observation will include 1) clinical assessment-with the determination of the New York Heart Association functional class and exercise capacity in the 6-minute walk test (6MWT); 2) echocardiography-with the assessment of global and segmental left ventricular systolic function, mitral valve function, and the presence of fluid in the pleural and pericardial cavities; 3) parameters of pacing, sensing, lead impedance, and ventricular arrhythmic events recorded by the ICD/CRT-D; 4) QoL; and 5) procedure-related adverse events. Evaluation will be performed at 1, 3, 6, 12, and 18 months post-procedure, with endpoints assessed at 6 and 18 months.
The co-primary endpoints will assess 1) treatment efficacy, defined as the number of events of monomorphic sVT over six months following the comparison procedures, and 2) treatment safety, defined as no procedure-related serious adverse events.
The most important clinical parameters evaluating the effectiveness of ablation (i.e., post-procedural reduction in the sVT burden, occurrence/time to the first sVT episode, number of adequate ICD/CRT-D therapies, number of hospitalizations for arrhythmic reasons, QoL improvement) and mortality (death from any cause) were selected as secondary endpoints.
623 studies on the registry are indexed under Tachycardia; 81 are open to participants now.
This study's planned enrollment of 150 is above the median of 64 across 379 interventional studies indexed under Tachycardia.
Browse Tachycardia studies →Medical University of Silesia is the lead sponsor of 111 studies on the registry; 24 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
In the arm randomized to STAR (alternative experimental therapy), the procedure will involve the elimination of the sVT substrate using ionizing radiation at a dose of 25 Gy, employing highly conformal stereotactic techniques. The STAR procedure will be performed in a radiation oncology department according to a protocol developed by the research team, based on the American Association of Physicists in Medicine (AAPM) report on stereotactic radiotherapy, guidelines for radiotherapy in patients with cardiac implantable electronic devices (CIEDs), and the expert consensus on the implementation and use of STAR in treatment-resistant sVT.
Radiation: Stereotactic Arrhythmia Radioablation (STAR)
In the arm randomized to CA (reference - standard therapy), the procedure will involve the elimination of the sVT substrate using energy transmitted from a generator through a catheter. The CA procedure will be performed in accordance with the expert consensus of the Heart Rhythm Society (HRS), European Heart Rhythm Association (EHRA), Asia Pacific Heart Rhythm Society (APHRS), and Latin American Heart Rhythm Society (LAHRS) on ventricular arrhythmia ablation.
Procedure: Catheter Ablation
Radiotherapy Implementation: During treatment on a TrueBeam™ linear accelerator (Varian Medical Systems, Palo Alto, CA, USA), a planned radiation dose of 25 Gy will be delivered to the defined planning target volume (PTV) using highly conformal stereotactic techniques. Image-guided radiotherapy (IGRT), respiratory gating, and Triggered Tracking will be utilized, targeting the previously delineated defibrillation lead of the implantable cardioverter-defibrillator (ICD) or cardiac resynchronization therapy defibrillator (CRT-D), with position verification every 15 degrees of gantry rotation. Patient positioning will be performed using kV-kV imaging, based on pre-determined fiducial markers on the ICD/CRT-D defibrillation lead, followed by verification using gated cone-beam computed tomography (CBCT). Continuous ECG monitoring will be conducted throughout the treatment, and the patient will remain under cardiologist supervision.
CA will be conducted in an electrophysiology laboratory and will routinely follow diagnostic procedures, including an electrophysiological study (EPS) and three-dimensional electroanatomical mapping (3D-EAM). Once sufficient data on the nature and location of the arrhythmic substrate have been obtained from the three primary mapping modules-voltage, activation, and propagation-spatial 3D-EAM maps will be integrated with a 3D left ventricular reconstruction from multislice computed tomography (MSCT) or cardiac magnetic resonance (CMR). Subsequently, ablation will be performed by delivering energy to predefined target sites identified as the arrhythmia source to close the sVT isthmus or eliminate late potentials (LPs) and/or low-amplitude ventricular activities (LAVAs). Following CA, a repeat induction attempt of sVT using programmed ventricular pacing (VP) will be conducted to verify procedural efficacy.
The burden of ventricular arrhythmias, defined as the total number of sustained ventricular tachycardia (sVT) events recorded during the 6-month observation period.
Each documented sustained ventricular tachycardia (sVT) event, captured via electrocardiogram (ECG) or intracardiac electrogram (EGM) from the CIED memory, will be subject to physician adjudication. Automatic classification of arrhythmia type, number of sVT episodes, and number of therapies performed by the CIED will be accepted only in cases where EGM recordings are unavailable, e.g., due to device memory overflow resulting from a high volume of episodes. sVT criteria: 1. Meets detection criteria in the active VT or VF zone programmed in the ICD/CRT-D and triggers an appropriate therapy; or 2. Meets detection criteria in the VT monitoring zone programmed in the ICD/CRT-D and lasts ≥ 30 seconds; or 3. Is misclassified by the ICD/CRT-D as a supraventricular tachycardia but is reclassified as sVT after physician review of the EGM; or 4. Is recorded on surface ECG with a duration of ≥ 30 seconds.
Time frame: 6 months
Absence of treatment-related serious adverse events (SAEs) during the 18-month follow-up period
All adverse events (AEs) assessed by the investigator as having a probable causal relationship with either the experimental therapy or standard therapy will be classified as adverse events and recorded in the study protocol. Serious Adverse Events (SAEs) Each adverse medical event meeting any of the following criteria will be classified as a Serious Adverse Event (SAE): * Results in the death of the patient. * Is life-threatening to the patient. * Results in permanent or significant disability or requires intervention to prevent permanent damage to tissues or organs. * Requires re-hospitalization or leads to an extension of the hospitalization related to the procedure by more than 24 hours.
Time frame: 18 months
Reduction in ventricular arrhythmia burden, measured as the percentage decrease in the mean monthly number of sustained ventricular tachycardia events during the 6-month follow-up after therapy initiation, compared to corresponding period pre-treatment
Sustained ventricular arrhythmias will be counted as stated in the Primary Outcome Measures.
Time frame: 6 months
Occurrence of sVT during the 18-month follow-up period
Sustained ventricular arrhythmias will be counted as stated in the Primary Outcome Measures.
Time frame: 18 months
Time to first occurrence of sVT during the 18-month follow-up period.
Sustained ventricular arrhythmias will be counted as stated in the Primary Outcome Measures.
Time frame: 18 months
Number of appropriate ICD/CRT-D therapies delivered during the 18-month follow-up period.
Appropriate therapy will be defined as: a. Therapy (ATP or shock) delivered by the ICD/CRT-D due to sVT and confirmed by physician adjudication (after excluding supraventricular arrhythmias and/or sensing abnormalities); or b. External electrical or pharmacological cardioversion following physician-confirmed documentation of sVT on ECG. Only one therapy will be counted per sVT episode. In cases where multiple therapies are delivered sequentially during a single episode, the final effective therapy leading to episode termination will be considered and counted.
Time frame: 18 months
Number of hospitalizations due to arrhythmic causes during the 18-month follow-up period.
Number of hospitalizations due to arrhythmic causes during the 18-month follow-up period.
Time frame: 18 months
All-cause mortality during the 18-month follow-up period.
All-cause mortality during the 18-month follow-up period.
Time frame: 18 months
Improvement in quality of life assessed using the Polish version of the World Health Organization Quality of Life-BREF (WHOQOL-BREF) questionnaire during the 18-month follow-up period.
Improvement in quality of life assessed using the Polish version of the World Health Organization Quality of Life-BREF (WHOQOL-BREF) questionnaire during the 18-month follow-up period.
Time frame: 18 months
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Medical University of Silesia