Imaging Study of Allocation of Pacing Targets in Cardiac Resynchronization Therapy

Not Applicable

Completed

• Conditions: Systolic Heart Failure; Dysynchrony; Image Guidance; Digital Twins; Cardiac Resynchronization Therapy

• Registration Number: NCT01640769
• Lead Sponsor: Libin Cardiovascular Institute of Alberta

Brief Summary

This randomized controlled trial will assess a cardiac MRI derived 4D digital cardiac model to optimized left and right ventricular lead delivery to improve response to cardiac resynchronization therapy.

Detailed Description

Regional mechanical delay, myocardial scar, and inter-lead distance have each been demonstrated to be relevant variables for the realization of optimal response to cardiac resynchronization therapy (CRT). Pilot study results have suggested clinical feasibility and potential value from LV and RV lead navigation aimed at optimizing these combined variables. A computer software program has been developed to deliver an interactive, 4D digital heart model of mechanical dyssynchrony and myocardial scar to guide LV and RV CRT lead delivery to optimal targets. This multi-center randomized clinical trial has been designed to assess the feasibility, safety and clinical impact of LV-RV lead navigation using a web-deployed 4D cardiac model.

Study Timeline

• Study First Submitted: 2012-07-09
• Study First Submitted QC: 2012-07-11
• Study First Posted: 2012-07-16
• Study Start: 2014-09-01
• Primary Completion: 2022-01
• Study Completion: 2023-01-01
• Status Verified: 2025-06
• Last Update Submitted: 2025-06-18
• Last Update Posted: 2025-06-25

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 210

Inclusion Criteria

1. Age ≥ 18 years.
2. Ejection fraction ≤ 35 %.
3. LBBB with QRS duration ≥ 120 msec.
4. NYHA class II-IV.
5. On maximum tolerated heart failure medication therapy ≥ 6 weeks.
6. Clinically accepted for CRT device implantation.

Exclusion Criteria

1. Failure to provide consent.
2. CCS class III-IV angina.
3. Recent Q-wave myocardial infarction or revascularization procedure ( ≤ 3 months).
4. Atrial fibrillation at time of randomization >6 weeks in duration
5. Standard contra-indications to MRI.
6. Documented severe allergy to intravenous contrast dye ( iodinated CT contrast or Gadolinium MRI contrast).
7. Estimated Glomerular Filtration Rate (eGFR) ≤ 45 ml/min/m2.
8. Patient is pregnant.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Determination of response to image guided placement of cardiac ventricular pacing leads in cardiac resynchronization therapy (CRT)	6 months	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 (multigated acquisition scan / wall motion study).

Secondary Outcome Measures

Name	Time	Method
All-cause mortality	12 months
Heart failure hospital admissions	12 months
improvement in 6-minute hall walk ≥ 30 meters or ≥ 10%	6 months	6 minute hallwalk will be done at baseline, 3 months and 6 months
Improvement in Quality of Life (QOL) score by ≥ 10 points	6 months	A "Minnesota Living with Heart Failure" questionnaire will be administered at baseline, 3 months and 6 months (visual analogue score out of 100)
Procedural complications	6 months	All procedural complications will be recorded following completion of procedure and at 3 and 6 months.
Device complications	6 months	All device-related complications, inclusive of need for lead repositioning, will be recorded at 3 months and 6 months.
Improvement in New York Heart Association (NYHA) functional class by ≥ 1	6 months	NYHA class will be determined at baseline, 3 months and 6 months (score out of 4)
Rate of concordant lead delivery to the "optimal myocardial target"	6 month	On the day of procedure, a post lead implant bi-plane fluoroscopy image and PA-LAT CXR will be obtained. These will be reviewed by a core laboratory to score final lead tip (electrode) location using a standardized report form to determine delivery location based on the AHA segmental model.
Total procedural time	6 month	Total procedural time from first needle to skin closure, in minutes
Fluoroscopy dose and exposure time	6 month	Total fluoroscopy exposure time and radiation dose will be recorded at end of procedure and recorded (in minutes).

Trial Locations

Locations (5)

Conect Research, University of Calgary; 🇨🇦 Calgary, Alberta, Canada

Halifax Capital Districy Health Authority; 🇨🇦 Halifax, Nova Scotia, Canada

Libin Cardiovascular Institute; 🇨🇦 London, Ontario, Canada

Ottawa Heart Institute Research Corporation; 🇨🇦 Ottawa, Ontario, Canada

University of Laval Research Centre; 🇨🇦 Quebec City, Quebec, Canada