Contrast ICE for Myocardial Scar in VT Ablations

Contrast Enhanced Intracardiac Echocardiography (ICE) for Localization of Myocardial Scar During Ablation of Ventricular Tachycardia

There is a high correlation between scar areas identified by contrast-enhanced ICE and scar areas identified by conventional electroanatomic mapping. Therefore, the investigators will assess the utility of contrast-enhanced ICE to identify and localize myocardial scar real-time during VT ablation procedures.

Study Overview

• Status: Completed
• Conditions: Ventricular Tachycardia; Ischemic Cardiomyopathy
• Intervention / Treatment: Drug: Perflutren Lipid Microsphere Intravenous Suspension [DEFINITY]

Detailed Description

Ventricular tachycardia (VT) is a life-threatening arrhythmia which occurs frequently in the setting of structural heart disease, most often as result of myocardial fibrosis or scar. Catheter ablation is often performed to treat recurrent VT, but is predicated on precise localization of myocardial scar, as scar is often the source of VT. Currently during VT ablation procedures the identification of scar is based on electroanatomic mapping where bipolar voltage criteria have been established (i.e., bipolar electrogram voltage < 1.5 mV is considered scar). However this definition is purely based on electrical signal information and so has significant limitations: 1) there has not been definitive establishment of the sensitivity and specificity of this threshold for defining scar in comparison with tissue; 2) a detailed 3-D map created by time-consuming movement of the mapping catheter must be obtained in order to assess the existence and location of the scar; 3) only scar on the surface in contact with the mapping catheter (most often endocardial) may be definitively identified, whereas there may be intramyocardial or epicardial scar that would not be identified unless the mapping catheter makes direct contact with those areas which may involve additional risky access (epicardial) or even impossible (intramyocardial). For these reasons it would be very helpful to have another method to identify and localize myocardial scar during a VT ablation procedure. Cardiac MRI has been validated for identifying and localizing scar, but would not be recommended for many patients due to presence of ICD (implantable cardioverter-defibrillator) devices in these patients. Contrast-enhanced echocardiography has been validated to identify myocardial scar (Montant 2010), and intracardiac echocardiography (ICE) is standardly used in VT ablation procedures. Therefore, the investigators will assess the utility of contrast enhanced ICE by identifying and localizing myocardial scar real-time during VT ablation procedures.

• Study Type: Interventional
• Enrollment (Actual): 24
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 100 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Subject is 18 years of age or older
• Subject is undergoing catheter ablation of likely reentrant VT
• Planned use of intracardiac echocardiography (ICE)
• Subject is willing to sign and date the study informed consent form

Exclusion Criteria:

• Contraindication to Perflutren (Optison) echo contrast
• Known right-to-left, bidirectional, or transient right-to-left cardiac shunts
• Known hypersensitivity to Perflutren, blood, blood products or albumin
• Subject has medical condition that would limit study participation (as per MD discretion)
• Subject is pregnant
• Inability to give informed consent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Definity; Perflutren echo contrast is infused to enhance intracardiac echo imaging recorded during catheter ablation of ventricular tachycardia. We will compare areas that appear to be myocardial scar on ultrasound with areas of abnormal electrical signals obtained by direct catheter mapping.	Drug: Perflutren Lipid Microsphere Intravenous Suspension [DEFINITY]; Perflutren 1.3mL diluted in 50 mL is infused intravenously, and intracardiac echo imaging is recorded to analyze for areas of possible myocardial scar, which is then compared with areas of abnormal electrical signal via direct catheter mapping which is performed during ablation of ventricular tachycardia.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Subjects With Myocardial Scar on Echo and Voltage Maps	location of left ventricular myocardial scar and abnormal electrograms	day 0 (intraoperative: data collected during the mapping procedure)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Subjects With Ventricular Tachycardia Mapped	If ventricular tachycardia was induced and mapped then this counts as yes	day 0 (intraoperative: data collected during the mapping procedure)

Collaborators and Investigators

• Sponsor: Weill Medical College of Cornell University
• Collaborators: Biosense Webster, Inc.
• Investigators: Principal Investigator: Christopher Liu, MD, Weill Medical College of Cornell University

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2013
• Primary Completion (Actual): September 1, 2018
• Study Completion (Actual): December 1, 2018

Study Registration Dates

• First Submitted: July 6, 2017
• First Submitted That Met QC Criteria: July 6, 2017
• First Posted (Actual): July 11, 2017

Study Record Updates

• Last Update Posted (Actual): June 12, 2019
• Last Update Submitted That Met QC Criteria: May 31, 2019
• Last Verified: May 1, 2019

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Heart Diseases; Cardiovascular Diseases; Arrhythmias, Cardiac; Cardiac Conduction System Disease; Tachycardia; Tachycardia, Ventricular; Cardiomyopathies
• Other Study ID Numbers: 1205012398

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No