Ischemic Cardiomyopathy, Ventricular Tachycardia
Conditions
Brief summary
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.
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.
Interventions
DRUGPerflutren 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.
Sponsors
Biosense Webster, Inc.
Weill Medical College of Cornell University
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 100 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Number of Subjects With Myocardial Scar on Echo and Voltage Maps | day 0 (intraoperative: data collected during the mapping procedure) | location of left ventricular myocardial scar and abnormal electrograms |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Number of Subjects With Ventricular Tachycardia Mapped | day 0 (intraoperative: data collected during the mapping procedure) | If ventricular tachycardia was induced and mapped then this counts as yes |
Participant flow
Recruitment details
Patients recruited from hospital inpatient ward and from electrophysiology laboratory procedure suites. Recruitment commenced March 2013, and ended March 2016.
Participants by arm
| Arm | Count |
|---|---|
| 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.
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. | 24 |
| Total | 24 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Physician Decision | 4 |
Baseline characteristics
| Characteristic | Definity | — |
|---|---|---|
| Age, Continuous | 66.6 years STANDARD_DEVIATION 10.1 | — |
| left ventricular ejection fraction among subjects | 25 percent | — |
| number of subjects with hypertension | 10 Participants | — |
| number of subjects with implanted defibrillator | 21 Participants | — |
| number of subjects with ischemic cardiomyopathy | 18 Participants | — |
| Race and Ethnicity Not Collected | — | — Participants |
| Region of Enrollment United States | 24 participants | — |
| Sex: Female, Male Female | 2 Participants | — |
| Sex: Female, Male Male | 22 Participants | — |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 24 |
| other Total, other adverse events | 0 / 24 |
| serious Total, serious adverse events | 0 / 24 |
Outcome results
Primary
Number of Subjects With Myocardial Scar on Echo and Voltage Maps
location of left ventricular myocardial scar and abnormal electrograms
Time frame: day 0 (intraoperative: data collected during the mapping procedure)
Population: 3 of 24 enrolled subjects did not have voltage mapping, and 1 of 24 subjects did not have echo contrast injection; thus a total of 4 subjects did not have both echo contrast and voltage mapping in order to allow scar comparison; therefore the 20 subjects with complete echo and voltage maps were analyzed.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Definity | Number of Subjects With Myocardial Scar on Echo and Voltage Maps | 20 Participants |
Secondary
Number of Subjects With Ventricular Tachycardia Mapped
If ventricular tachycardia was induced and mapped then this counts as yes
Time frame: day 0 (intraoperative: data collected during the mapping procedure)
Population: 4 of 24 enrolled subjects did not inducible ventricular tachycardia; thus a total of 4 subjects did not have both scar and ventricular tachycardia mapping in order to allow scar comparison; therefore the 20 subjects with complete scar and ventricular tachycardia maps were analyzed.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Definity | Number of Subjects With Ventricular Tachycardia Mapped | 20 Participants |