Dual-Source Computed Tomography to Improve Prediction of Response to Cardiac Resynchronization Therapy (DIRECT)

This study is ongoing, but not recruiting participants.
Brigham and Women's Hospital
St. Jude Medical
Information provided by (Responsible Party):
Jagmeet Singh, Massachusetts General Hospital
ClinicalTrials.gov Identifier:
First received: March 25, 2010
Last updated: June 22, 2014
Last verified: June 2014
Cardiac Resynchronization Therapy (CRT) is a widely accepted treatment that has led to improved clinical outcomes for patients with refractory congestive heart failure (CHF), systolic dysfunction, and wide QRS duration. However, it requires implantation of an expensive device ($30,000) and about 1/3 of patients do not have clinical improvement. Inadequate amounts of LV dyssynchrony or suboptimal lead placement may limit clinical response. Dual-Source computed tomography (DSCT) allows for subtle detection during myocardial contraction for assessing LV dyssynchrony, and can also assess coronary venous anatomy and scar burden. Thus DSCT may be the ideal noninvasive modality to predict response to CRT.

Condition Intervention
Heart Failure - NYHA II - IV
Wide QRS Complex
Other: Randomization of Pre-knowledge of CT coronary venography

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Dual-Source Computed Tomography to Improve Prediction of Response to Cardiac Resynchronization Therapy

Resource links provided by NLM:

Further study details as provided by Massachusetts General Hospital:

Primary Outcome Measures:
  • Clinical Response to CRT [ Time Frame: 6 months post implantation of CRT ] [ Designated as safety issue: No ]
    The clinical response to CRT will be adjudicated by two experienced cardiologists taking into account left ventricular ejection fraction, NYHA functional class, and patient global assessment score.

Secondary Outcome Measures:
  • Major adverse cardiovascular events (MACE) [ Time Frame: 2 years ] [ Designated as safety issue: No ]
    MACE defined as composite endpoints of death, cardiac transplant, left ventricular assist device, and HF hospitalization

  • Secondary endpoints [ Time Frame: 6 months ] [ Designated as safety issue: No ]
    Change in NYHA Functional Class, Echo volumes and ejection fraction, Minnesota Quality of Life score, 6-minute walk distance, NT-proBNP levels, and hospitalization at 6 months

Other Outcome Measures:
  • Implantation and fluoroscopy time and radiation exposure [ Time Frame: During time of implant ] [ Designated as safety issue: No ]
    Implantation time, fluoroscopy time, and radiation exposure

  • Agreement between CT venography and invasive coronary venography [ Time Frame: within the CT venography and invasive coronary venography ] [ Designated as safety issue: No ]

Biospecimen Retention:   Samples With DNA
Whole blood

Estimated Enrollment: 60
Study Start Date: February 2009
Estimated Study Completion Date: September 2016
Estimated Primary Completion Date: September 2014 (Final data collection date for primary outcome measure)
Groups/Cohorts Assigned Interventions
Pre-procedural cardiac CT
CRT patients will undergo pre-procedural cardiac CT to assess for dyssynchrony, scar, and coronary venous anatomy. The CT venogram will be randomize to pre-knowledge to implanting physician or blinded. The CT dyssynchrony and scar assessment will remain blinded to caregivers and patients.
Other: Randomization of Pre-knowledge of CT coronary venography


Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
Outpatient or inpatient heart failure patients scheduled for CRT implantation

Inclusion Criteria:

  • Older than 18 years of age
  • Ability to provide informed consent
  • Planned CRT implantation
  • NYHA Functional Class II-IV heart failure
  • Echo Ejection Fraction less than or equal to 35%
  • QRS duration greater than or equal to 120 ms
  • Normal or mildly reduced kidney function (estimated serum creatinine less than or equal to 1.5 mg/dL or less than or equal to 1.3 mg/dL for diabetic subjects on metformin
  • For diabetic subjects on glucophage (metformin) they will be required to stop glucophage (metformin) for at least 48 hours after the administration of contrast.

Exclusion Criteria:

  • Known allergy to iodine or iodinated contrast
  • Chronic persistent atrial fibrillation
  • Pregnancy or unknown pregnancy status
  • Subjects on glucophage (metformin) therapy that are unable or unwilling to discontinue therapy for 48 hours after CT scan
  • Known inadequate venous access for appropriate IV caliber placement
  • Iodinated contrast administration within the past 48 hours
  • Subjects who cannot hold their breath for 10-15 seconds
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT01097733

United States, Massachusetts
Massachusetts General Hospital
Boston, Massachusetts, United States, 02114
Sponsors and Collaborators
Massachusetts General Hospital
Brigham and Women's Hospital
St. Jude Medical
Principal Investigator: Jagmeet P Singh, MD, PhD Massachusetts General Hospital
  More Information

Responsible Party: Jagmeet Singh, Jagmeet Singh, MD, Massachusetts General Hospital
ClinicalTrials.gov Identifier: NCT01097733     History of Changes
Other Study ID Numbers: 2008P000555  1K23HL098370 
Study First Received: March 25, 2010
Last Updated: June 22, 2014
Health Authority: United States: Institutional Review Board

ClinicalTrials.gov processed this record on May 03, 2016