Imaging Study of Allocation of Pacing Targets in Cardiac Resynchronization Therapy

Study Overview
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Brief Summary
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Magnetic Resonance Image guided delivery of Left and Right Ventricular Leads to optimal myocardial targets will result in improved clinical response to CRT using Left Ventricular remodeling criteria.

Detailed Description
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Cardiac Dyssynchrony and scar are important variables for realization of clinical response to cardiac resynchronization therapy (CRT). Results from a previous study suggest that paced heart segment characteristics do predict this response and our ability to identify venous pathways to optimal segments is feasible using cardiac CT and MRI. In an ongoing feasibility study we are using these capabilities to guide the delivery of CRT lead systems to optimal myocardial targets. A computer software program has been developed that can create an interactive, 3D integrated cardiac model of coronary vein anatomy, myocardial scar and mechanical dyssynchrony. Although this feasibility study is ongoing, early results show this method of guiding the CRT leads to optimal targets with these individualized models to be safe and effective. This trial will be a larger multi-centre randomized blinded trial to determine the therapeutic impact of MRI guided Left Ventricular and Right Ventricular lead placement with respect to improving clinical response rates for CRT.

Official Title
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MRI Allocation of Pacing Targets in Cardiac Resynchronization Therapy

Conditions
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Systolic Heart Failure

Intervention / Treatment
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* Procedure: Image guided delivery of cardiac pacing leads.
* Procedure: Standard delivery of cardiac pacing leads.


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age ≥ 18 years. Ejection fraction ≤ 35 %. QRS duration ≥ 120 msec. NYHA class II-IV. On maximum tolerated heart failure medication therapy ≥ 6 weeks. Clinically accepted for CRT device implantation. Exclusion Criteria: Failure to provide consent. CCS class III-IV angina. Recent Q-wave myocardial infarction or revascularization procedure ( ≤ 3 months). Standard contra-indications to MRI. Documented severe allergy to intravenous contrast dye ( iodinated CT contrast or Gadolinium MRI contrast). Estimated Glomerular Filtration Rate (eGFR) ≤ 45 ml/min/m2. Patient is pregnant.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Image guided delivery of pacing leads<br>Patients will be blindly randomized to image guided delivery of pacing leads during cardiac resynchronization therapy device implantation (study arm) versus standard implantation of pacing leads during cardiac resynchronization therapy device implantation (control arm). | Procedure: Image guided delivery of cardiac pacing leads.<br>* Patients will be blindly randomized to image guided delivery of pacing leads during cardiac resynchronization therapy device implantation (study arm).<br>|
| Placebo Comparator: Standard delivery of pacing leads<br>Patients will be blindly randomized to standard implantation of pacing leads during cardiac resynchronization therapy device implantation (control arm). | Procedure: Standard delivery of cardiac pacing leads.<br>* Patients will be blindly randomized to standard implantation of pacing leads during cardiac resynchronization therapy device implantation (control arm).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Determination of response to image guided placement of cardiac ventricular pacing leads in cardiac resynchronization therapy (CRT) | Cardiac Resynchronization Therapy (CRT) response will be defined as a change in the Left Ventricular Ejection Fraction measured at 6 months post CRT device implant by MUGA ( cardiac wall motion study) scan. | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To determine if image guided lead delivery will result in a higher rate of lead delivery to optimal myocardial segments. | Cardiac CT scan will be performed at 3 months post CRT device implantation to determine secondary outcome listed above. The left ventricular (LV) lead site will be assessed for targets of dysychronous myocardium and proximity to scar tissue. The right ventricular (RV) lead will be assessed for proximity to scar tissue. | 3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cardiomyopathy, Cardiac Resynchronization Therapy