Functional Substrate-Only Guided VT Ablation

NCT06464315 | Enrolling By Invitation DMC

• 1 other identifier: CARA-007-23F
• Study Type: interventional
• Target: 36
• Locations: 1 country
• Sites: 1

Brief Summary

Ventricular tachycardia (VT) is a leading cause of death and suffering in the Veteran population. Currently, ablation procedures are performed to destroy the diseased tissue that causes this problem. This study will test to see if an experimental strategy of only targeting regions of slow conduction without the induction of VT can improve the efficacy and safety of VT ablation. Once this study is completed, the investigators will know whether this ablation strategy could help increase the efficacy, safety and efficiency of ablation therapy of fatal heart rhythms.

Conditions

Ventricular Tachycardia; Sudden Cardiac Death

Keywords

functional substrate mapping; conduction slowing; isochronal late activation mapping (ILAM); peak frequency signal analysis; deceleration zones

Outcome Measures

Primary Outcomes (1)

• Time to composite endpoint (VT recurrence, death, or acute hemodynamic decompensation)

  Ventricular arrhythmia recurrence is defined by an episode of sustained VT lasting 30 seconds or appropriate implantable cardioverter-defibrillator therapy including anti-tachycardia pacing or shock. Acute hemodynamic decompensation is defined by escalation of at least 1 new high dose inotrope/pressor occurring after anesthesia induction with persistent requirement during stable rhythm, \>20% drop in cardiac index, unplanned insertion of percutaneous hemodynamic support device.

  6 months

Secondary Outcomes (7)

• VT burden (ICD therapy including shocks and ATP, sustained VT episodes >30 seconds)

  6 months

• Total Mapping Time

  immediately at the end of the procedure

• Total fluoroscopy time

  immediately at the end of the procedure

• total procedural time

  immediately at the end of the procedure

• Procedural adverse events or complications

  1 month

Study Arms (2)

Functional substrate mapping only without VT induction

EXPERIMENTAL

In this experimental arm, only functional substrate mapping will be used to guide ablation of conduction slowing regions, without VT induction or mapping during VT. Ablation targets of conduction slowing will be identified as: 1) deceleration zones of conduction slowing, previously defined as 3 isochrones coalescing within 1cm radius. 2) wavefront discontinuities represented by lines of conduction block, previously defined as late potentials with at least 20ms of isoelectric segment, and 3) regions of slow conduction characterized by high peak frequency (220-500Hz), which uses spectral frequency analysis to identify signals with highest frequency as a surrogate for slow conduction. All regions exhibiting any of these 3 surrogates of slow conduction will be ablated.

Procedure: Functional Substrate-Only Mapping without VT Induction

Standard VT Mapping

ACTIVE COMPARATOR

Standard-of-care mapping, including voltage mapping of intrinsic rhythm, entrainment, activation, and/or pace mapping, will be performed to guide VT ablation. Standard VT induction protocols will be performed.

Procedure: Standard-of-Care Mapping/Imaging

Interventions

Functional Substrate-Only Mapping without VT Induction PROCEDURE

In this arm, invasive maps will be constructed by annotating the latest deflection and peak frequency during voltage mapping of stable intrinsic rhythm to localize areas of slow conduction. Annotated algorithms are cleared by the FDA. No VT will be purposefully induced in this experimental arm.

Also known as: Isochronal late activation mapping (ILAM), peak frequency analysis

Functional substrate mapping only without VT induction

Standard-of-Care Mapping/Imaging PROCEDURE

Conventional invasive scar (voltage) and electrical VT (entrainment, activation, pace) mapping will be used to guide VT ablation. Functional substrate mapping will not be used in this arm. VT will be induced using standard protocols.

Standard VT Mapping

Eligibility Criteria

• Age: 18 Years - 90 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Men and women \>18 years of age referred for clinically indicated VT ablation and experience monomorphic or polymorphic scar-based VT documented by telemetry, ICD interrogation, ECG or event monitoring.
• Scar-based VT is defined as VT in patients with structural heart disease (assessed with either abnormal nuclear perfusion imaging (\>5% defect), late gadolinium uptake on cardiac MRI, wall thinning \<10mm or calcified myocardium on cardiac CT, akinesis or hypokinesis on echocardiogram, presence of Q waves on ECG, history of myocardial infarct).
• Patients undergoing epicardial VT ablation and who undergo prophylactic percutaneous hemodynamic support devices will also be included.

You may not qualify if:

• Patients without structural heart disease will be excluded from the pri-mary analysis, but enrolled in a prospective registry
• Patients who are pregnant
• Presence of intracardiac thrombus
• active acute coronary ischemia with unrevascularized coronary artery disease (CAD \>70% stenosis)
• Active bacteremia
• Inaccessible ventricles due to dual mechanical valves
• Inability to tolerate and inability to tolerate anticoagulation during ablation and for at least 1 month after ablation

Sponsors & Collaborators

• VA Office of Research and Development: lead

Study Sites (1)

VA San Diego Healthcare System, San Diego, CA

San Diego, California, 92161-0002, United States

Location

MeSH Terms

Conditions

Tachycardia, Ventricular; Death, Sudden, Cardiac

Interventions

X-Rays

Condition Hierarchy (Ancestors)

Tachycardia; Arrhythmias, Cardiac; Heart Diseases; Cardiovascular Diseases; Cardiac Conduction System Disease; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Heart Arrest; Death, Sudden; Death

Intervention Hierarchy (Ancestors)

Electromagnetic Radiation; Electromagnetic Phenomena; Magnetic Phenomena; Physical Phenomena; Radiation; Radiation, Ionizing

Study Officials

• Gordon Ho, MD

  VA San Diego Healthcare System, San Diego, CA

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: This is a prospective, single-blinded, randomized controlled trial comparing an experimental strategy of functional substrate mapping/ablation only without VT induction compared to standard VT mapping/ablation. The study subjects will be blinded to the randomization. The care providers doing the procedure (and/or investigators doing the procedure) cannot be blinded by nature of the intervention (either perform experimental mapping protocol or not).
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: FED
• Responsible Party: SPONSOR

Model Details: Randomized controlled trial

Study Record Dates

• First Submitted: May 23, 2024
• First Posted: June 18, 2024
• Study Start: March 18, 2026
• Primary Completion (Estimated): September 28, 2029
• Study Completion (Estimated): April 1, 2030
• Last Updated: March 25, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)