We are updating the design of this site. Learn more.
Show more
ClinicalTrials.gov Menu

Evaluation of Resynchronization Therapy for Heart Failure (EARTH) (EARTH)

This study has been completed.
ClinicalTrials.gov Identifier:
First Posted: May 13, 2009
Last Update Posted: May 8, 2012
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.
St. Jude Medical
Canadian Institutes of Health Research (CIHR)
Information provided by (Responsible Party):
Bernard Thibault, Montreal Heart Institute
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 Intervention Phase
Heart Failure Device: Device programming Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Official Title: Evaluation fo Resynchronization Therapy for Heart Failure (EARTH)

Resource links provided by NLM:

Further study details as provided by Bernard Thibault, Montreal Heart Institute:

Primary Outcome Measures:
  • The primary endpoint is total exercise duration at a constant submaximal load (ETT submaximal load is defined as 75% of peak exercise during the baseline metabolic evaluation) [ Time Frame: one year ]

Secondary Outcome Measures:
  • Clinical, electrical, echocardiographic, MUGA scan endpoints, Neuro-hormones [ Time Frame: one year ]

Estimated Enrollment: 120
Study Start Date: October 2003
Study Completion Date: February 2010
Primary Completion Date: February 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: LV Pacing
left univentricular pacing
Device: Device programming
6-month period
Active Comparator: BV Pacing
biventricular pacing
Device: Device programming
6-month period

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.

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.

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

Inclusion Criteria (for Greater and Lesser EARTH):

Patient must answer "yes"

  1. Does the patient require an ICD or an ICD replacement?
  2. Does the patient have a documented LVEF less than or equal to 35% measured in the previous 6 months (without major concomitant clinical event)?
  3. Does the patient have a QRS duration < 120 ms?
  4. Is the patient in sinus rhythm?
  5. Was the six-minute walk test distance less than 400 meters and limited by heart failure symptoms?

Exclusion Criteria:

Patient must have answered "NO" to all of the exclusion criteria

  1. Does the patient have:

    • Indication for permanent ventricular pacing?
    • Chronotropic insufficiency?
    • Second or third degree AV block, either persistent or intermittent?
    • A pacemaker or an ICD which is paced in ventricular chamber more than 5% of the time?
  2. Does the patient have a reversible cause of LV dysfunction such as post-partum cardiomyopathy, tachycardia induced cardiomyopathy, acute myocarditis or acute toxic cardiomyopathy (including acute alcoholic)?
  3. Did the patient have myocardial infarction or cardiac surgery in the 6 weeks preceding the pre-implant visit?
  4. Does the patient have a moderate or severe cardiac valve stenosis?
  5. Is the patient's capacity to walk is limited by reasons other than heart failure symptoms (e.g., angina, intermittent claudication, severe lung condition or arthritis)?
  6. Does the patient have severe coexisting illnesses making survival > 6 months unlikely?
  7. Is the patient pregnant and/or nursing?
  8. Is the patient unable or unwilling to consent or to comply with follow-up requirements?
  9. Is the patient participating in another clinical study potentially interfering with the present trial?
  10. Does the patient have a resynchronization system in place?
  Contacts and Locations
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 ClinicalTrials.gov identifier (NCT number): NCT00901212

Canada, Alberta
University of Alberta Hospital
Edmonton, Alberta, Canada, T6G 2B7
Canada, British Columbia
St-Paul's Hospital
Vancouver, British Columbia, Canada, V6Z 1Y6
Canada, Nova Scotia
QEII Health Sciences Centre
Halifax, Nova Scotia, Canada, B3H 3A7
Canada, Ontario
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
Montreal, Quebec, Canada, H1T1C8
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
St. Jude Medical
Canadian Institutes of Health Research (CIHR)
Study Chair: Bernard MD, Thibault Montreal Heart Institute Research Center
  More Information