Multimodality Assessment of Ventricular Scar Arrhythmogenicity.

Can MRI-based Computational Modelling of the Heart be Used to Predict Critical Substrate in Scar-dependent Ventricular Tachycardia Ablation?

We aim to improve our understanding of a life-threatening heart rhythm disorder known as ventricular tachycardia (VT). This is a disorder which originates from the lower chamber of the heart and frequently is associated with heart disease. We will use an MRI scan to generate a computer based model of the heart which can predict areas of the heart which are important in generating this rhythm disorder. We intend to assess how accurate this computer model is compared to traditional invasive assessment of the heart muscle. We also aim to assess the electrical characteristics of those areas which were predicted by the computer model in order to see why they were thought to be so important.

All patients seen at St George's Hospital with VT will be eligible. As is routine for these patients, they will have an MRI scan of the heart. We will then use this scan to create a virtual reconstruction of the heart from which predictions of the critical areas of the heart which are generating the rhythm problem will be made. Then we will perform a VT ablation (studying the electrical properties and if necessary making a burn to treat the rhythm problem) - as per standard of care, however during the ablation we will spend extra time collecting information comparing the accuracy of the computer-generated model to the traditional invasive signals which guide ablation. We will study the electrical properties of those predicted areas to see what is special about them. The study will last up to three years.

Study Overview

• Status: Completed
• Conditions: Ventricular Tachycardia
• Intervention / Treatment: Diagnostic test: Generation of computational model from cardiac MRI.; Procedure: VT ablation

Detailed Description

Patients will be eligible for this trial both from referrals as an outpatient, where VT has been detected on a heart rhythm monitor or ECG (electrical heart tracing), or as an inpatient where they have been admitted to hospital with symptoms of VT. Our study investigators will discuss the research with the patient and give them the relevant information in an understandable format as part of a Patient Information Sheet so that they can make an informed decision about whether or not to participate in the research.

An MRI scan of the heart is a standard investigation for patients presenting with VT, however if the patient is included in the study, the MRI scan images will be anonymised and sent confidentially to the Institute of Computational Modelling at Johns Hopkins University in USA where the images will be reconstructed into a 3D representation of the patients heart, where the electrical pathways and source of the VT can be seen. This information will be sent back (again confidentially and anonymously) to St George's Hospital in time for their routine VT ablation procedure.

During the VT ablation The MRI scan model will be combined with the invasively-obtained information and we will assess the various areas of the heart which are responsible for the VT, particularly relating to areas of scar within the heart, which are frequently seen in these patients. We will assess the electrical properties of the areas highlighted as the cause of the VT from the MRI scan.

We will assess the accuracy of the computer model compared to the traditional invasive measurements that we take. We will first ablate those areas of the heart which the model predicted as being important (as long as the invasive characteristics support ablation there) and then see what effect this had on the electrical properties of other areas of the heart. However, we will not ablate any area of the heart based solely on the MRI model; it will only influence the order of ablation and not tell us whether to ablate or not.

The procedure can take 4-6 hours in total. The extra information gathered as part of the research protocol may extend this by a maximum of 10%. No extra pieces of equipment, procedures or medications are involved in the research, just the time taken to generate a computer model of the heart as well as a extra time to assess the heart in more detail during the ablation.

Following the ablation, the patients will be followed at 3, 6 and 12 months with a heart rhythm monitor and a clinical review as an outpatient as per routine standard of care. From this, we will collect data on frequency of recurrence of rhythm disturbance, therapy from their implantable cardioverter-defibrillators, symptoms and complications following the ablation procedure.

The information gathered during the procedure will be analysed and research papers generated from the results.

• Study Type: Observational
• Enrollment (Actual): 18

Contacts and Locations

Study Locations

• United Kingdom
  • London, United Kingdom, SW17 0QT
    • St George's University Hospitals NHS Foundation Trust

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: N/A

• Sampling Method: Non-Probability Sample

Study Population

The study setting is a large tertiary centre hospital in London, St George's University Hospital which serves a population of around 1.3 million. It also receives referrals from district general hospitals in the surrounding area. Referrals are made to a specialist arrhythmia clinic from which suitable patients can be identified. The majority of recruited patients are expected to be outpatients who are symptomatic from VT despite optimal medical therapy. This will allow sufficient time to perform the cardiac MRI and to generate the computational model. In some scenarios, emergency admissions with symptomatic VT may be included if they are suitable for inpatient VT ablation and there is sufficient time for the MRI and computation analysis to take place prior to the VT ablation.

Description

Inclusion Criteria:

Adult inpatients admitted to St George's Hospital London with sustained ventricular tachycardia or outpatients identified from the arrhythmia clinic with significant monomorphic ventricular tachycardia noted on cardiac monitoring who:

• Have sustained, monomorphic scar-dependent ventricular tachycardia
• Are symptomatic
• Failed, unable or unwilling to tolerate anti-arrhythmic medications
• Able to have a cardiac MRI
• Have a life expectancy > 1 year
• At least 40 days following a myocardial infarction

Exclusion Criteria:

• Patients under the age of 18
• Patients who are unable to give informed consent
• Pregnant patients
• Unable to have cardiac MRI
• Prohibitive procedural risk
• Unable to tolerate the ablation procedure due to haemodynamic instability

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Cases; Patients with scar-dependent ventricular tachycardia, requiring ablation. These patients will have satisfied the inclusion/exclusion criteria and be put forward for VT ablation. They will undergo the previously described study protocol, including generation of a computational model of the heart from their cardiac MRI and a VT ablation where we will study the points of interest generated from the MRI model in detail.

Diagnostic test: Generation of computational model from cardiac MRI.; Routine cardiac MRI scan results will be sent to Johns Hopkins University where a computer-generated model of the heart will be made, which will demonstrate predicted areas critical to VT generation and maintenance. This data will be sent back to St George's, and integrated with the standard VT ablation mapping software to allow comparison of its accuracy with standard mapping techniques.; Procedure: VT ablation; Routine VT ablation as described elsewhere in the literature. However, a brief period of extra time (~30 minutes) will be spent analysing the areas of the heart which the MRI scan predicted as being important for generation of VT. We will study the effect of ablation of these areas (if indicated) on distant parts of the heart.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Electrogram Duration at Digital Twin Predicted Sites Compared to Non-predicted Sites	Duration of electrograms at digital twin predicted sites compared to non-predicted sites on invasive mapping within areas of bipolar low voltage (<1.5mV)	During ablation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Symptom Assessment at 12 Month Clinical Follow up	Assessment of patient's symptoms at a clinical consultation following the ablation.	12 months

Collaborators and Investigators

• Sponsor: St George's, University of London
• Collaborators: Johns Hopkins University
• Investigators: Study Director: Magdi Saba, MD, St George's Hospital / SGUL; Study Director: Anthony Li, MD, St George's Hospital

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2021
• Primary Completion (Actual): April 2, 2024
• Study Completion (Actual): April 2, 2024

Study Registration Dates

• First Submitted: October 20, 2020
• First Submitted That Met QC Criteria: November 11, 2020
• First Posted (Actual): November 17, 2020

Study Record Updates

• Last Update Posted (Actual): May 30, 2025
• Last Update Submitted That Met QC Criteria: May 13, 2025
• Last Verified: April 1, 2023

More Information

Terms related to this study

• Keywords: ablation; cardiac MRI; ventricular tachycardia; computational modelling
• Additional Relevant MeSH Terms: Cardiac Conduction System Disease; Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Tachycardia; Tachycardia, Ventricular
• Other Study ID Numbers: 2020.0237

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Not applicable - participant data will not be shared with other researchers outside the study group.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No