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Localization of CRT According to Echocardiography: LOCATE-Pilot Study

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00234611
Recruitment Status : Unknown
Verified November 2006 by Michigan Heart, PC.
Recruitment status was:  Active, not recruiting
First Posted : October 7, 2005
Last Update Posted : November 6, 2006
Information provided by:
Michigan Heart, PC

Brief Summary:
Currently, the majority of heart failure patients who qualify for and receive a cardiac resynchronization therapy (CRT) device feel better than before their implant. However, there are some patients who do not improve after the implant. Michigan Heart is sponsoring a research study called LOCATE-Pilot to help understand whether the information from an echocardiogram, performed before implanting the CRT device, improves patients’ responses to CRT. This is being done by evaluating your heart’s function with an echocardiogram, to measure your heart’s response during therapy. The study hypothesis is that response to CRT may be optimized by guiding left ventricular lead placement to the maximally delayed, viable basal segment of the left ventricle.

Condition or disease Intervention/treatment Phase
Heart Failure Procedure: Echocardiogram guided left ventricular lead placement Not Applicable

Detailed Description:

CRT is a promising treatment modality for medically-refractory New York Heart Association (NYHA) class III or IV heart failure (HF) patients with intraventricular conduction delay (QRS > 130 ms). The randomized trials also suggest that a substantial minority of patients do not benefit, either echocardiographically or clinically, from CRT. In the MIRACLE trial, for instance, 35% of patients did not clinically improve after CRT. Objective reverse remodeling, typically defined as >15% reduction in the end-systolic volume, occurs in approximately 60% of patients. Most echocardiographic studies to date have reported only short- and intermediate-term results.

The objectives of the LOCATE-Pilot study are as follows: 1) to determine the proportion of patients undergoing CRT or CRT with defibrillator (CRT-D) with interpretable pulsed-wave tissue Doppler echocardiographic signals to quantitate and localize mechanical dyssynchrony; 2) to determine how frequently the LV lead can be successfully implanted in the most delayed basal segment (area of maximal delay); 3) to determine whether TDI guidance of CRT improves the proportion of patients with an echocardiographic response to treatment (reverse remodeling) at 6 months; 4) to determine whether TDI guidance of CRT improves the proportion of patients with a clinical response to treatment (6 min walk time, major clinical vascular events, or Minnesota Living with Heart Failure Quality of Life score); 5) to confirm that echocardiographic targeting of LV lead implantation is safe and does not hamper efficiency in the electrophysiological laboratory; 6) to validate the peak velocity delay (PVD) as a predictor of CRT response using pulsed-wave Doppler tissue imaging.

The LOCATE-pilot is a randomized, prospective study of 60 patients undergoing implantation of a Medtronic market approved CRT system. All patients will undergo a comprehensive baseline echocardiographic study in which a 6-segment model will be used to quantify dyssynchrony by the pulsed-wave Doppler technique. Myocardial viability will be assessed by conventional 2D criteria and nuclear perfusion data when available. Patients will be randomized to 1 of 2 groups with 30 patients per group on an intention-to-treat basis: 1) Control group: the implanting physician will have no knowledge of the baseline dyssynchrony assessment and use the current standard of care in the LV lead implantation; and 2) Echo-Guided group: the implanting physician will have full knowledge of baseline echocardiographic study and will use the dyssynchrony and viability data to guide final LV lead placement.

For this pilot study, patients will be followed for 6 months with a repeat Echocardiogram at 6 months. The primary endpoint of the study is indexed end systolic volume decrease >15% by biplane Simpson’s technique.

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Study Type : Interventional  (Clinical Trial)
Enrollment : 60 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double
Primary Purpose: Treatment
Official Title: Localization of CRT According to Echocardiography: LOCATE-Pilot Study
Study Start Date : September 2005
Study Completion Date : April 2007

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Heart Failure

Primary Outcome Measures :
  1. Efficacy: Indexed end systolic volume decrease>15% by biplane Simpson's technique at 6 month follow-up.
  2. Safety: CRT implantation morbidity; mortality

Secondary Outcome Measures :
  1. Clinical composite (6 month clinical assessment in HF clinic): 6 minute hall walk distance, MLWHF QOL score, NYHA functional classification
  2. Clinical outcome at study termination (6 month follow-up for last patient enrolled): vital status (all cause mortality), cardiac mortality, unplanned hospitalization for major cardiovascular event
  3. Proportion of diagnostic pulsed wave Doppler baseline studies
  4. Success rate at Echo guided implantation (implantation of LV lead to target segment)
  5. Outcomes stratified by concordance (pacing most delayed, viable segment)

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years to 80 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • male/female patients
  • NYHA class III and IV chronic heart failure
  • symptoms refractory to standard therapy (beta blocker and either ACE-I or ARB on stable dosages for 1 month minimum and duration of 3 months therapy minimum)
  • patient has signed and dated informed consent
  • patient able to receive pectoral device implant
  • QRS>= 130 ms
  • EF <= 35%
  • follow-up at Michigan Heart CHF clinic feasible
  • patient understanding of protocol and willing to comply

Exclusion Criteria:

  • recent myocardial infarction (<3 months)
  • recent surgical or percutaneous revascularization (<3months)
  • age < 18 months
  • permanent AF without AV junction ablation
  • life expectancy under 6 months
  • women of child-bearing potential and not willing or able to take birth control
  • mechanical tricuspid valve
  • prior orthotopic heart transplantation
  • intermittent inotropic therapy or inotropic-dependent

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00234611

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United States, Michigan
Michigan Heart, PC
Ypsilanti, Michigan, United States, 48197
Sponsors and Collaborators
Michigan Heart, PC
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Principal Investigator: Steven E Girard, MD, PhD Michigan Heart, PC


Layout table for additonal information Identifier: NCT00234611     History of Changes
Other Study ID Numbers: MH-MDT-01
First Posted: October 7, 2005    Key Record Dates
Last Update Posted: November 6, 2006
Last Verified: November 2006
Additional relevant MeSH terms:
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Heart Failure
Heart Diseases
Cardiovascular Diseases