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Evaluation of Resynchronization Therapy for Heart Failure (EARTH)

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: NCT00900549
Recruitment Status : Terminated (Futility reason, no difference between study groups)
First Posted : May 13, 2009
Last Update Posted : July 21, 2011
Abbott Medical Devices
Canadian Institutes of Health Research (CIHR)
Information provided by:
Montreal Heart Institute

Brief Summary:
Heart failure is a major health problem in Canada. Recent advances in medical and device therapy have helped to reduce the morbidity and mortality of patients with this problem. Among these treatments, cardiac resynchronization therapy (CRT) has very recently been shown to be effective to improve functional class, quality of life and exercise tolerance of the patients with the most severe symptoms of heart failure and a prolonged duration of the QRS on the 12-lead Electrocardiography (ECG).

Condition or disease Intervention/treatment Phase
Heart Failure Device: CRT on Device: CRT off Phase 4

Detailed Description:
Resynchronization of the failing ventricle is currently achieved by pacing the left and right ventricles simultaneously with specialized electrodes and a cardiac stimulator. However, controversy persists concerning the optimal configuration for cardiac pacing in these patients. Right ventricular pacing alone has been shown to be deleterious in some patient populations. The benefits of biventricular pacing in heart failure patients may be due primarily to left ventricular stimulation and may, in some patients, be decreased by the presence of simultaneous RV stimulation. Preliminary data from our own animal work suggest that in the majority of cases, LV stimulation alone is better than RV stimulation, and that BiV stimulation represents an intermediary situation between LV and RV stimulation.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 120 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Official Title: EvaluAtion of Resynchronization Therapy for Heart Failure (EARTH)
Study Start Date : October 2003
Actual Primary Completion Date : February 2011
Actual Study Completion Date : July 2011

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Heart Failure

Arm Intervention/treatment
Experimental: CRT Device: CRT on
12 months

Sham Comparator: No CRT Device: CRT off

Primary Outcome Measures :
  1. Total exercise duration at a constant submaximal load (defined as 75% of peak exercise during the baseline metabolic evaluation); study is powered to detect a min difference of 300 sec (+25% from baseline) in the primary endpoint between the 2 treatments [ Time Frame: one year ]

Secondary Outcome Measures :
  1. Clinical & electrical endpoints and echocardiographic & nuclear medicine evaluation of LV function. Dyssynchrony evaluation will help advancing the understanding of the physiopathology of heart failure and response to resynchronization therapy. [ Time Frame: one year ]

Information from the National Library of Medicine

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

Inclusion Criteria:

  • The patients are eligible if they undergo an ICD implantation or replacement
  • They have a documented LVEF ≤ 35% measured in the previous 6 months (without major clinical subsequent event, such as heart surgery, since the LVEF measurement)
  • If measured by echocardiography, the LV end-diastolic diameter must be ≥ 60 mm
  • The duration of the QRS is < 120 ms
  • They are in sinus rhythm
  • They cannot walk more than 400 meters during the screening 6-minute walk test (the patients must be limited by heart failure symptoms)

Exclusion Criteria:

  • Patients with an indication for permanent ventricular pacing or with chronotropic insufficiency defined as follow:

    • Any condition where the treating physician believes it would not be acceptable for the patient to have his device NOT programmed with the SENSOR at ON for the duration of the study
    • Second or third degree AV block, either persistent or intermittent
    • Patients with a pacemaker or an ICD who are paced in the ventricular chamber more than 5% of the time
  • Patients with LV dysfunction associated with a reversible cause such as post-partum cardiomyopathy, tachycardia induced cardiomyopathy, acute myocarditis or acute toxic cardiomyopathy (including acute alcoholic)
  • Patients who had a myocardial infarction within the past 6 weeks* defined by 2 of the 3 following conditions:

    • Prolonged chest pain
    • ECG changes suggesting of AMI
    • Cardiac enzymes elevation more than twice the local upper limit of normal)
  • Patients who had cardiac surgery within the past 6 weeks*
  • Patients with moderate or severe cardiac valve stenosis (aortic, mitral, pulmonary or tricuspid)
  • Patients with an inability or a limitation to walk for reasons other than heart failure symptoms (e.g., angina, intermittent claudication, severe lung condition or arthrosis)
  • Patients with severe coexisting illnesses making survival > 6 months unlikely
  • Patients who are pregnant and/or nursing.
  • Patients with inability or unwillingness to consent or comply with follow-up requirements
  • Patients participating in another study

The 6-week period is calculated prior to the beginning of the baseline evaluation and not the implant procedure itself. This difference comes from the fact that the protocol includes a delay of 2 to 8 weeks between the implant procedure and the actual beginning of the patient's evaluation.

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): NCT00900549

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Canada, Alberta
University of Alberta Hospital
Edmonton, Alberta, Canada, T6G 2B7
Canada, Nova Scotia
QEII Health Sciences Centre
Halifax, Nova Scotia, Canada, B3H 3A7
Canada, Ontario
Hamilton Health Sciences Center
Hamilton, Ontario, Canada, L8L 2X2
University of Ottawa Heart Institute
Ottawa, Ontario, Canada, K1Y 4W7
Sunnybrook & Women's Hospital
Toronto, Ontario, Canada, M4N 3M5
St-Michael's Hospital
Toronto, Ontario, Canada, M5B 1W8
Canada, Quebec
Fleurimont, Quebec, Canada, J1H 5N4
Montreal Heart Institute Research Center
Montreal, Quebec, Canada, HIT1C8
CHUM-Hôpital Hotel-Dieu
Montréal, Quebec, Canada, H2W 1T8
Sacre-Coeur Hospital
Montréal, Quebec, Canada, H4J 1C5
Institut Univ de Cardiologie et de Pneumologie de Québec
Québec, Quebec, Canada, G1V 4G5
Sponsors and Collaborators
Montreal Heart Institute
Abbott Medical Devices
Canadian Institutes of Health Research (CIHR)
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Study Chair: Bernard Thibault, MD Montreal Heart Institute

Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Bernard Thibault, MD, Montreal Heart Institute Identifier: NCT00900549     History of Changes
Other Study ID Numbers: UCT67914 (Lesser Earth)
ISRCTN 42560370
First Posted: May 13, 2009    Key Record Dates
Last Update Posted: July 21, 2011
Last Verified: July 2011

Keywords provided by Montreal Heart Institute:
Heart failure
Cardiac resynchronization therapy

Additional relevant MeSH terms:
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Heart Failure
Heart Diseases
Cardiovascular Diseases