Effect of Targeting Left Ventricular Lead Position on the Rate of Response to Cardiac Resynchronization Therapy.
Information source: University of Calgary
Information obtained from ClinicalTrials.gov on June 20, 2008
Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Heart Failure, Congestive; Cardiac Pacing, Artificial; Defibrillators
Intervention: A (Procedure); B (Procedure)
Phase: Phase 2/Phase 3
Status: Active, not recruiting
Sponsored by: University of Calgary
Official(s) and/or principal investigator(s):
Derek V Exner, MD, MPH, Principal Investigator, Affiliation: Libin Cardiovascular Institute of Alberta, University of Calgary
Identifying & optimizing strategies to reduce the burden of heart failure is vital. Despite
advances in pharmacotherapy, patients with heart failure are at high risk for death &
hospitalization. Cardiac resynchronization therapy (CRT) synchronizes ventricular mechanical
activity, improves cardiac output & reduces HF symptoms. However, ~50% of patients do not
clearly respond to CRT. Sub-optimal placement of the LV pacing lead appears to be an
important reason for non-response.
This study will assess whether targeted LV lead placement will result in an increased
probability of CRT response at 52 weeks vs. usual (lateral wall) lead placement.
Official title: Investigating Non-Response to Cardiac Resynchronization: Evaluation of Methods to Eliminate Non-Response & Target Appropriate Lead Location (INCREMENTAL).
Study design: Treatment, Randomized, Double Blind (Subject, Caregiver, Outcomes Assessor), Parallel Assignment, Safety/Efficacy Study
Primary outcome: Response to cardiac resynchronization therapy (reduction in end systolic volume and reduction in symptoms).
Minnesota Living with Heart Failure score.
Short form thirty six score.
Specific Activity Scale score.
New York Heart Association class.
Six minute walk distance.
Augmentation in regional LV systolic function with dobutamine.
N-terminal pro-B-type natriuretic peptide.
Microvolt alternans voltage.
Background. Identifying & optimizing strategies to reduce the burden of heart failure (HF) is
vital. Despite advances in pharmacotherapy, patients with HF are at high risk for death &
hospitalization. Over 25% of patients with systolic HF have dyssynchronous ventricular
contraction that results in paradoxical septal motion, further impairing left ventricular
(LV) function & HF progression. Cardiac resynchronization therapy (CRT) synchronizes
ventricular mechanical activity, improves cardiac output & reduces HF symptoms. However, ~50%
of patients do not clearly respond to CRT. Sub-optimal placement of the LV pacing lead
appears to be an important reason for non-response.
Screening. Mechanical synchrony is vitally important in optimizing CRT response. Patients
will be pre-screened with echocardiograms (echo) & CRT provided to only those with
dyssynchrony. The predicted rate of CRT response in patients pre-screened for dyssynchrony is
estimated at 65%.
CRT response. The combined use of a valid & simple measure of functional capacity with a
reproducible measure of LV volume is optimal in identifying CRT responders. These outcomes
will be assessed using the Specific Activity Scale & radionuclide angiography (RNA),
Primary hypothesis. Targeted LV lead placement will result in an increased probability of CRT
response at 52 weeks vs. usual (lateral wall) lead placement. CRT response will be defined as
≥ 10% relative reduction in LV end systolic volume & ≥ 1 Specific Activity Scale class
Minimum age: 18 Years.
Maximum age: N/A.
- LV EF ≤ 0. 40 measured within 3 months of enrollment,
- SAS class 3 or 4 symptoms indicative of moderate to severe functional capacity
limitation due to heart failure within 1 month of enrollment.
- Confirmed dyssynchrony on screening echo (1. 1.9), &
- On stable doses of ACE inhibitor or angiotensin II blocker & a beta-blocker for ≥ 2
months unless medically contra-indicated.
- Controlled heart rate if in permanent AF (resting <70 & maximal <120).
- Unable or unwilling to provide informed consent,
- Medical condition other than heart failure likely to cause death < 1 year,
- Cardiac transplant planned within 6 months,
- Known contra-indication to transvenous CRT device implant (e. g., active sepsis,
artificial tricuspid valve, known vascular occlusion that will prevent delivery of
- Clinically significant myocardial infarction within last 2 months, or
- Coronary bypass graft surgery ≤ 2 months or coronary angioplasty ≤ 1 month
Locations and Contacts
Foothills Hospital, Calgary, Alberta T2N4N1, Canada
Quebec Heart Institute, Ste-Foy, Quebec G1V4G5, Canada
Starting date: January 2005
Ending date: November 2010
Last updated: March 11, 2008