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

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.

Study Overview

• Status: Completed
• Conditions: Wide QRS Complex; Heart Failure - NYHA II - IV
• Intervention / Treatment: Other: Randomization of Pre-knowledge of CT coronary venography

• Study Type: Observational
• Enrollment (Actual): 38

Contacts and Locations

Study Locations

• United States
  • Massachusetts
    • Boston, Massachusetts, United States, 02114
      • Massachusetts General Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

Outpatient or inpatient heart failure patients scheduled for CRT implantation

Description

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

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
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

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinical Response to CRT	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.	6 months post implantation of CRT

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Major adverse cardiovascular events (MACE)	MACE defined as composite endpoints of death, cardiac transplant, left ventricular assist device, and HF hospitalization	2 years
Secondary endpoints	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	6 months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Implantation and fluoroscopy time and radiation exposure	Implantation time, fluoroscopy time, and radiation exposure	During time of implant
Agreement between CT venography and invasive coronary venography		within the CT venography and invasive coronary venography

Collaborators and Investigators

• Sponsor: Massachusetts General Hospital
• Collaborators: Brigham and Women's Hospital; Abbott Medical Devices
• Investigators: Principal Investigator: Jagmeet P Singh, MD, PhD, Massachusetts General Hospital

Publications and helpful links

General Publications

• Truong QA, Singh JP, Cannon CP, Sarwar A, Nasir K, Auricchio A, Faletra FF, Sorgente A, Conca C, Moccetti T, Handschumacher M, Brady TJ, Hoffmann U. Quantitative analysis of intraventricular dyssynchrony using wall thickness by multidetector computed tomography. JACC Cardiovasc Imaging. 2008 Nov;1(6):772-81. doi: 10.1016/j.jcmg.2008.07.014.
• Galand V, Ghoshhajra B, Szymonifka J, Das S, Orencole M, Barre V, Martins RP, Leclercq C, Hung J, Truong QA, Singh JP. Left ventricular wall thickness assessed by cardiac computed tomography and cardiac resynchronization therapy outcomes. Europace. 2020 Mar 1;22(3):401-411. doi: 10.1093/europace/euz322.
• Truong QA, Szymonifka J, Picard MH, Thai WE, Wai B, Cheung JW, Heist EK, Hoffmann U, Singh JP. Utility of dual-source computed tomography in cardiac resynchronization therapy-DIRECT study. Heart Rhythm. 2018 Aug;15(8):1206-1213. doi: 10.1016/j.hrthm.2018.03.020. Epub 2018 Mar 20.

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2009
• Primary Completion (Actual): January 1, 2012
• Study Completion (Actual): January 1, 2012

Study Registration Dates

• First Submitted: March 25, 2010
• First Submitted That Met QC Criteria: March 31, 2010
• First Posted (Estimate): April 2, 2010

Study Record Updates

• Last Update Posted (Actual): October 3, 2022
• Last Update Submitted That Met QC Criteria: September 30, 2022
• Last Verified: September 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Heart Diseases; Cardiovascular Diseases; Heart Failure
• Other Study ID Numbers: 2008P000555; 1K23HL098370 (U.S. NIH Grant/Contract)