Clinical trial NCT03713866: Peri-Procedural Transmural Electrophysiological (EP) Imaging of Scar-Related Ventricular Tachycardia
Official title: Peri-Procedural Transmural Electrophysiological Imaging of Scar-Related Ventricular Tachycardia
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Ventricular Tachycardia
Myocardial Infarction
Lead sponsor: Nova Scotia Health Authority
Sponsor class: OTHER
Collaborators: name: Nova Scotia Health Authority
name: Rochester Institute of Technology
First posted: 2018-10-22
Enrollment: 20
Sex: ALL
Minimum age (years): 18
Maximum age (years): 85
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: DIAGNOSTIC

Brief summary: Ventricular tachycardia (VT) contributes to over 350,000 sudden deaths each year in the US. Malignant VTs involve an electrical "short circuit" in the heart, formed by narrow channels of surviving tissue inside myocardial scar. An important treatment is to use catheter ablation to "block" the channel that forms the circuit. Effective ablation requires imaging guidance to visualize the VT circuit relative to scar structures in 3D. Unfortunately, with conventional catheter mapping, up to 90% of the VT circuits are too short-lived to be mapped. For the 10% "mappable" VTs, their data are only available during ablation and limited to one ventricular surface. This inadequacy of functional VT data largely limits the knowledge about scar-related VT and ablation strategies, and reduces the ability of clinicians to identify ablation targets and assess ablation outcome.

The central hypothesis of this proposal is that functional VT data, integrated with CT or MRI scar data in 3D, can improve VT ablation efficacy with pre-procedural identification of ablation targets and post-procedural mechanistic elucidation of ablation failure. This research builds on the rapidly increasing clinical interest in electrocardiographic imaging (ECGi), an emerging technique that obtains cardiac electrical activity through inverse reconstructions from ECGs. The specific objective is to push the boundary of ECGi to provide - as a conjunction to intra-procedural catheter mapping - pre-ablation and post-ablation imaging of functional VT circuits integrated with 3D scar structure.

Detailed description: Electrocardiographic imaging (ECGi) is an emerging technique to image cardiac electrical activity through inverse reconstructions from body-surface ECGs. After 40 years of active research, the potential of ECGi as a noninvasive adjunct to catheter mapping is gaining rapid attention in the clinical community.

A total of 40 consecutive post-infarction VT patients will be prospectively enrolled and recruited from those who have been referred for catheter ablation of scar-related VT. Within 7 days before the ablation procedure, these patients will undergo noninvasive cardiac CT or MRI imaging and noninvasive programmed stimulation (NIPS) study with simultaneous 120-lead body- surface ECG mapping (pre-ablation NIPS). MRI will be performed for patients with implantable defibrillators for whom it is considered safe to do so. CT imaging will be performed for those with Implantable Cardioverter Defibrillators (ICDs) which are not MRI compatible.

At the time of scheduled ablation, all patients will undergo standard catheter mapping and ablation procedure as a part of standard care. Within 7 days after the ablation procedure, the patients will undergo cardiac MRI imaging and noninvasive programmed stimulation (NIPS) with simultaneous 120-lead body-surface ECG mapping (post-ablation NIPS). For patients who cannot undergo MRI, CT imaging will not be repeated.

At 6 months after the procedure, a follow-up will occur as a part of standard care where outcome data regarding the chronic success of the ablation procedure will be collected and ICD interrogation will be performed. No imaging or mapping is planned at the follow-up.

Eligibility criteria: Inclusion Criteria:

* One or more episodes of sustained monomorphic VT
* Referred for catheter ablation
* Previously implanted ICD
* Signed the patient informed consent form
* Able and willing to comply with all pre-, post-, and follow-up testing and requirements

Exclusion Criteria:

* Have estimated Glomerular Filtration Ratio (eGFR) less than 30
* Have a life expectancy less than 6 months or are listed for heart transplantation at time of inclusion
* Are pregnant
* Are on IV inotropic agents
* Have any contraindication to catheter ablation (including but not limited to mechanical prosthetic aortic and mitral valves, known protruding Left Ventricular (LV) thrombus
* New York Heart Association (NYHA) functional class IV
* Had ST wave elevation myocardial infarction within \< 1 month
* Unwilling or unable to undergo cardiac MRI scan AND unwilling or unable to undergo cardiac CT scan (e.g. contrast allergy).

Primary outcomes:
measure: Termination of Ventricular Tachycardia
timeFrame: Less than 10 minutes post ablation
measure: VT recurrence rate
timeFrame: Less than 6 months post procedure
Secondary outcomes:
Other outcomes:
Locations:
city: Halifax
country: Canada
facility: QEII HSC
state: Nova Scotia
Study officials:
affiliation: Nova Scotia Health Authority
name: John L Sapp, MD FRCPC
role: PRINCIPAL_INVESTIGATOR
References: