Clinical trial NCT06138873: Ablation-Index Guided Scar-Mediated Ventricular Tachycardia Ablation in Patients With Ischemic Cardiomyopathy
Official title: Ablation-Index Guided Scar-Mediated Ventricular Tachycardia Ablation in Patients With Ischemic Cardiomyopathy (AIM-VT) - a Prospective Single-Blinded, Multicenter Randomized Controlled Trial
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Ventricular Tachycardia
Ischemic Cardiomyopathy
Keywords: ventricular
tachycardia
ablation index
ischemic cardiomyopathy
Lead sponsor: Rush University Medical Center
Sponsor class: OTHER
Collaborators: name: University of Michigan
name: Medical University of South Carolina
name: The Cleveland Clinic
name: Biosense Webster, Inc.
First posted: 2023-11-18
Enrollment: 100
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: Over the last decade, radiofrequency catheter ablation (RFCA) has become an established treatment for ventricular arrhythmias (VA). Due to the challenging nature of visualizing lesion formation in real time and ensuring an effective transmural lesion, different surrogate measures of lesion quality have been used. The Ablation Index (AI) is a variable incorporating power delivery in its formula and combining it with CF and time in a weighted equation which aims at allowing for a more precise estimation of lesion depth and quality when ablating VAs. AI guidance has previously been shown to improve outcomes in atrial and ventricular ablation in patients with premature ventricular complexes (PVC). However research on outcomes following AI-guidance for VT ablation specifically in patients with structural disease and prior myocardial infarction remains sparse. The investigators aim at conducting the first randomized controlled trial testing for the superiority of an AI-guided approach regarding procedural duration.

Detailed description: Over the last decade, radiofrequency catheter ablation (RFCA) has become an established treatment for ventricular arrhythmias (VA). RFCA uses electromagnetic energy that transforms into heat upon delivery into the myocardium and irreversibly damages the viable myocytes, causing the loss of cellular excitability. Irreversible loss of cellular excitability generally occurs at temperatures exceeding 50°C, while at lower temperatures, the damage is not permanent and myocytes can recover excitability, leading to VA recurrences. Due to the challenging nature of visualizing lesion formation in real time and ensuring an effective transmural lesion, different surrogate measures of lesion quality have been used. The fall in local impedance during ablation has been considered as a first marker of the direct effect of ablation in cardiac tissue but the generator impedance drop does not correlate well with lesion size. First, large impedance drops can indicate impeding steam pop without effective lesion formation. Second scar tissue carries a lower impedance than healthy tissue due to their higher water/collagen content and make impedance drops less reliable.

One of the major determinants of lesion formation is an adequate contact between the tip of the catheter and the myocardial surface. A first major technological advancement in ablation catheters was the development of sensors at the distal tip capable of monitoring contact (contact force, CF). A recent ablation marker is the Force-Time-Integral (FTI), which multiplies CF by radiofrequency application duration. Limitations in this ablation parameter are the exclusion of maximal power settings being delivered and the assumption that a single target FTI is required in all myocardial segments with varying wall thickness and underlying substrate. Also for prolonged energy deliveries, the contribution of radiofrequency application duration is proportionally less important in lesion creation than CF. To overcome some of these limitations, the Ablation Index (AI) was introduced. This is a variable incorporating power delivery in its formula and combining it with CF and time in a weighted equation. It has shown to be a more precise estimation of lesion depth and quality in animal models and humans than FTI, time alone or impedance drop.

AI guidance has previously been shown to improve outcomes in atrial and ventricular ablation in patients with premature ventricular complexes (PVC). However research on outcomes following AI-guidance for VT ablation specifically in patients with structural disease and prior myocardial infarction remains sparse, with mainly research conducted in ex-vivo porcine or canine models. In theory, use of AI to guide ablation in this subpopulation of VT patients may shorten procedure time and possibly improve procedural safety in comparison to ablation guided by less reliable conventional parameters or fixed energy application durations. First pilot studies assessing AI-guided VT ablations in patients with structural heart disease provided some observational insights on procedural parameters but our study is the first randomized controlled trial testing for the superiority of an AI-guided approach regarding procedural duration.

Eligibility criteria: Inclusion Criteria:

* Patient ≥ 18 y.o.
* Structural Heart Disease: Ischemic Cardiomyopathy
* Sustained Scar-related Monomorphic Ventricular Tachycardia documented by ECG or CIED interrogation

Exclusion Criteria:

* If clinical ventricular arrhythmia is predominantly PVCs, supraventricular tachycardia, or ventricular fibrillation
* Myocardial infarction or cardiac surgery within 6 months
* Severe mitral regurgitation
* Stroke or TIA within 6 months
* Prior VT substrate ablation in the previous 6 months
* NYHA functional class IV
* Non-ischemic VT substrate

Primary outcomes:
measure: Percentage reduction in ablation time between the groups with/without AI guidance
timeFrame: intra-procedural
Secondary outcomes:
measure: Percentage of reduction in total procedural duration in seconds between the AI/not AI group
timeFrame: intra-procedural
measure: Total intravenous fluids administered in milliliters (ml)
timeFrame: intra-procedural
measure: Fluoroscopy duration in minutes
timeFrame: intra-procedural
Other outcomes:
measure: Acute procedural success (no inducible VT), partial success (only non-clinical VT induced), and inducibility not tested at end of procedure (in number, % and risk-difference)
timeFrame: intra-procedural
measure: Average ablation time per lesion (in seconds and percentage difference)
timeFrame: intra-procedural
measure: Number of RF lesions per patient (number, mean with standard deviation/median with interquartile range and percentage difference)
timeFrame: intra-procedural
measure: Ablation Index per lesion (absolute value and percentage difference)
timeFrame: intra-procedural
measure: Steam pops (in number, percentage and risk-difference)
timeFrame: intra-procedural
measure: Impedance drop per lesion (in Ohm and percentage difference)
timeFrame: intra-procedural
measure: Recurrence event of sustained ventricular tachycardia or ICD therapy within 1 year (in number, % and risk-difference)
timeFrame: 1 year
measure: Complications within 7 days of ventricular tachycardia ablation procedure (in number, % and risk-difference, for the overall combined safety outcome and broken down for each complication)
timeFrame: 7 days post-intervention
measure: Overall hospitalizations after the procedure over 1 year (in number, percentage and risk-difference)
timeFrame: 1 year
measure: Cardiovascular hospitalizations after the procedure over 1 year (in number, percentage and risk-difference)
timeFrame: 1 year
measure: Death after ablation procedure from cardiovascular and/or non-cardiovascular cause over 1 year (in number, percentage and risk-difference)
timeFrame: 1 year
measure: Need for re-do ablations for sustained ventricular tachycardia or appropriate ICD therapy after index ventricular tachycardia ablation procedure over 1 year (in number, percentage and risk-difference)
timeFrame: 1 year
measure: Need for anti-arrhythmic drug anytime in the first year after ablation excluding the 1-month blanking period post-ablation (in number, percentage and risk-difference)
timeFrame: 1 year
Locations:
city: Chicago
country: United States
facility: Rush University Medical Center
state: Illinois
city: Ann Arbor
country: United States
facility: Medical University of Michigan
state: Michigan
city: Cleveland
country: United States
facility: Cleveland Clinic
state: Ohio
city: Charleston
country: United States
facility: Medical University of South Carolina
state: South Carolina
Study officials:
affiliation: Henry_D_Huang@rush.edu
name: Henry Huang, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Proietti R, Lichelli L, Lellouche N, Dhanjal T. The challenge of optimising ablation lesions in catheter ablation of ventricular tachycardia. J Arrhythm. 2020 Dec 28;37(1):140-147. doi: 10.1002/joa3.12489. eCollection 2021 Feb.
citation: Larsen T, Du-Fay-de-Lavallaz JM, Winterfield JR, Ravi V, Rhodes P, Wasserlauf J, Trohman RG, Sharma PS, Huang HD. Comparison of ablation index versus time-guided radiofrequency energy dosing using normal and half-normal saline irrigation in a porcine left ventricular model. J Cardiovasc Electrophysiol. 2022 Apr;33(4):698-712. doi: 10.1111/jce.15379. Epub 2022 Jan 30.
citation: Hussein A, Das M, Riva S, Morgan M, Ronayne C, Sahni A, Shaw M, Todd D, Hall M, Modi S, Natale A, Dello Russo A, Snowdon R, Gupta D. Use of Ablation Index-Guided Ablation Results in High Rates of Durable Pulmonary Vein Isolation and Freedom From Arrhythmia in Persistent Atrial Fibrillation Patients: The PRAISE Study Results. Circ Arrhythm Electrophysiol. 2018 Sep;11(9):e006576. doi: 10.1161/CIRCEP.118.006576.
citation: Gasperetti A, Sicuso R, Dello Russo A, Zucchelli G, Saguner AM, Notarstefano P, Soldati E, Bongiorni MG, Della Rocca DG, Mohanty S, Carbucicchio C, Duru F, Di Biase L, Natale A, Tondo C, Casella M. Prospective use of ablation index for the ablation of right ventricle outflow tract premature ventricular contractions: a proof of concept study. Europace. 2021 Jan 27;23(1):91-98. doi: 10.1093/europace/euaa228.
citation: Bates AP, Paisey J, Yue A, Banks P, Roberts PR, Ullah W. Radiofrequency Ablation of the Diseased Human Left Ventricle: Biophysical and Electrogram-Based Analysis. JACC Clin Electrophysiol. 2023 Mar;9(3):330-340. doi: 10.1016/j.jacep.2022.10.001. Epub 2022 Oct 10.