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Validation of Coronary Calcium Subtraction to Improve Diagnostic Accuracy of Coronary CT Angiography (C-Sub320)

This study has been completed.
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by (Responsible Party):
Klaus Fuglsang Kofoed, Rigshospitalet, Denmark Identifier:
First received: December 2, 2013
Last updated: November 5, 2016
Last verified: November 2016

Coronary calcium hampers accurate evaluation of the coronary arteries with coronary computed tomography angiography (CCTA). A novel approach to potentially overcome this limitation is coronary calcium subtraction.

The primary hypothesis of the study is:

- Coronary calcium subtraction CCTA will improve diagnostic accuracy as compared to conventional CCTA on a per-patient basis

Coronary Artery Disease

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Prospective International Study of Coronary Substraction Using 320 Row-detector CT

Further study details as provided by Rigshospitalet, Denmark:

Primary Outcome Measures:
  • Diagnostic accuracy of Coronary Subtraction Coronary CT angiography [ Time Frame: Within 90 days of ICA and CCTA ]
    Sensitivity, Specificity, Negative and Positive predictive value of Coronary Subtraction CT angiography by visual assessment to identify a >50% coronary stenosis as defined by invasive coronary angiography on a patient by patient level.

Secondary Outcome Measures:
  • Coronary CT angiography reader confidence [ Time Frame: Within 90 days of ICA and CCTA ]
    Coronary CT angiography reader confidence by a 3 level visual scale assessed on CT images without and with Coronary Calcium Subtraction

  • Coronary stenosis severity in non-diagnostic or partially diagnostic segments by conventional CCTA [ Time Frame: Within 90 days of ICA and CCTA ]
    In coronary segments deemed non-diagnostic or partially diagnostic due to calcification or coronary stents by conventional CCTA concordance of stenosis severity by Coronary Subtraction CT angiography and invasive quantitative coronary angiography is assessed

  • Coronary revascularization [ Time Frame: Within 30 days after CCTA ]
    On a patient by patient level the ability of CCTA to predict need for coronary revascularization (PCI or CABG) is assessed using CCTA without and with coronary calcium subtraction

Enrollment: 182
Study Start Date: October 2013
Study Completion Date: June 2016
Primary Completion Date: June 2016 (Final data collection date for primary outcome measure)
Detailed Description:

CCTA is a very important clinical method for the clinical evaluation of patients with chest pain of potential cardiac ischemic origin. However Coronary calcification and/or previously implanted coronary stents may limit the diagnostic accuracy of CCTA. A novel approach - coronary calcium subtraction - has been developed to potentially overcome this limitation.

  • Study Objective: To assess diagnostic accuracy using coronary calcium subtraction coronary CT angiography (CCTA) as compared to conventional CCTA.
  • Material and Methods: A total of 200 patients with suspected or known coronary artery disease (CAD) who have been referred for invasive coronary angiography (ICA) will prior to ICA undergo additional research CCTA with the newly developed coronary calcium subtraction protocol. Based on the coronary calcium scan (CS), coronary calcium score will be calculated according to the Agatston score. Conventional contrast enhanced CCTA studies will be analyzed for image quality and the presence and extent of coronary stenosis. Using a dedicated algorithm, subtraction will be performed on all datasets to obtain CCTA subtraction images. Subtracted images will be analyzed similar to the conventional CCTA images. ICA will serve as the gold standard. Image quality will be compared between conventional and subtracted CCTA. In addition, diagnostic accuracy in the evaluation of coronary stenosis as determined on ICA will be compared. Finally, factors influencing the performance of coronary calcium subtraction will be evaluated.

Ages Eligible for Study:   55 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
Patients (N=200) referred for in hospital invasive coronary evaluation

Inclusion Criteria:

  • Age > 55 Years
  • Scheduled for invasive coronary angiography
  • Logistically possible to perform CCTA before invasive evaluation

Exclusion Criteria:

  • Known Iodine-contrast allergy
  • Estimated GFR below 50 ml/min
  • Atrial fibrillation or other persistence cardiac arrythmia
  • Contraindication to betablockers (bronchospasm, LVEF less than 40%)
  • Implanted PM or ICD
  • Previous mechanical heart valve surgery
  • Inability to maintain breath-hold for at least 5 sec
  • Patient-related condition resulting the inability of the patient to understand the informed consent form of the study
  Contacts and Locations
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Please refer to this study by its identifier: NCT02011061

United States, Maryland
National Heart, Lung and Blood Institute
Bethesda, Maryland, United States, 20892
Department of Cardiology and Radiology, Rigshospitalet, The Heart Center, Capital Region of Copenhagen, University of Copenhagen
Copenhagen, Denmark, 2100
Sponsors and Collaborators
Rigshospitalet, Denmark
National Heart, Lung, and Blood Institute (NHLBI)
Principal Investigator: Klaus F Kofoed, MD, DmSc Rigshospitalet, University of Copenhagen, Denmark
  More Information

Responsible Party: Klaus Fuglsang Kofoed, associate professor, Rigshospitalet, Denmark Identifier: NCT02011061     History of Changes
Other Study ID Numbers: H-3-2013-108
ZIAHL006138 ( US NIH Grant/Contract Award Number )
Study First Received: December 2, 2013
Last Updated: November 5, 2016

Keywords provided by Rigshospitalet, Denmark:
Multidetector Computed Tomography
Coronary Stenosis
Coronary Artery Disease
Angina Pectoris

Additional relevant MeSH terms:
Coronary Artery Disease
Myocardial Ischemia
Coronary Disease
Heart Diseases
Cardiovascular Diseases
Arterial Occlusive Diseases
Vascular Diseases processed this record on April 21, 2017