High Definition CT Coronary Angiography Accuracy Trial

Diagnostic Performance of 64 Slice High Definition Computed Tomographic Coronary Angiography in Patients With High Risk of Significant Coronary Artery Disease.

CT technology is evolving at a rapid pace, with introduction of multidetector row CT scanners (MDCT) and electrocardiographic (ECG) gating resulting in increasing numbers of heart scans CTCA (CT Coronary Angiography). CTCA provides a noninvasive alternative to conventional invasive coronary angiography (ICA), which is considered the gold standard in the investigation of coronary disease. There has been a gradual increase in the utilization of CTCA for primary assessment of low and intermediate risk patients. However concerns regarding radiation exposure and diagnostic accuracy, especially in the highrisk group, have prevented its widespread dissemination.

To achieve best possible temporal resolution (minimize cardiac motion artifacts) and spatial resolution (provide diagnostic accuracy) relatively high radiation exposure is required, as a result of its inverse relationship with image noise and resolution. However radiation (X-ray) is associated with increased risk of cancer in exposed patients and it is therefore essential to continually devise strategies to reduce radiation exposure whilst maintaining image quality.

A state-of-art CT scanner (Discovery CT750 HD, General Electric (GE) Healthcare), has been installed at Derriford hospital for further research on CTCA. It uses novel method of scanning, High Definition Computed Tomographic Coronary Angiography(HD-CTCA), analogous to high definition television) and image reconstruction (Adaptive Statistical Iterative Reconstruction ASIR)as opposed to conventional CT scanners using Filtered Back Projection (FBP)reconstruction. HD-CTCA enables acquisition of sharper images and ASIR offsets the resultant increase in radiation exposure. This is likely to result in images of higher diagnostic quality with an equivalent or slightly lower radiation exposure compared to present technology. Although initial results are encouraging, this needs further assessment before being applied to routine clinical practice. To assess this we have designed a study to perform HD-CTCA on 300 consecutive patients undergoing diagnostic ICA at Derriford hospital, directly comparing the accuracy of HD-CTCA to ICA (presently considered the gold standard).

Hypotheses:

There is no significant difference in the sensitivity and specificity of HD-CTCA for the detection of coronary artery stenosis of 50% or greater compared to conventional ICA.

Study Overview

• Status: Completed
• Conditions: Coronary Artery Disease
• Intervention / Treatment: Radiation: Active Comparator: Invasive coronary angiography (ICA); Radiation: HD-CTCA with Adaptive statistical iterative reconstruction (ASIR)

• Study Type: Interventional
• Enrollment (Actual): 302
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Devon
    • Plymouth, Devon, United Kingdom, PL6 8BX
      • Plymouth Hospitals NHS Trust

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 40 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Patients > 40 years of age.
• Suspected or known coronary artery disease
• Admitted for diagnostic ICA

Exclusion Criteria:

• Consent cannot be obtained
• Age <40 years
• New York Heart Association (NYHA) Functional Classification - class III or IV heart failure
• Emergency imaging required (not enough time to consider the trial)
• Allergy to iodinated contrast or previous contrast induced nephropathy
• Intolerance to betablockers
• Uncontrolled rhythm disturbances (not suitable for CTCA)
• Serum Creatinine >200 micro mol/L within two weeks prior to procedure or chronic renal failure on dialysis

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Non-Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Invasive coronary angiography (ICA); Routine diagnostic ICA	Radiation: Active Comparator: Invasive coronary angiography (ICA)
Experimental: HD-CTCA with ASIR; HD-CTCA with Adaptive statistical iterative reconstruction (ASIR)within 4 weeks of routine diagnostic ICA	Radiation: HD-CTCA with Adaptive statistical iterative reconstruction (ASIR)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diagnostic accuracy of HD-CTCA for the detection of at least moderate stenosis (>50%) as defined on invasive coronary angiography in the high-risk target population.	We designed the New Generation Computed Tomographic Coronary Angiography (NG-CTCA) study to assess the diagnostic accuracy of high-definition CT with iterative reconstruction in an unselected population of patients suitable for CTCA with either a high pre-test probability of, or established coronary artery disease. Our hypothesis is that NGCT has a comparable diagnostic performance to invasive coronary angiography (ICA), using this as the reference standard	4 weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
The diagnostic accuracy of HD-CTCA for the detection of severe stenosis (70%) as defined by invasive coronary angiography.	4 weeks

Other Outcome Measures

Outcome Measure	Time Frame
The radiation dose delivered by HD-CTCA	4 weeks

Collaborators and Investigators

• Sponsor: University Hospital Plymouth NHS Trust
• Investigators: Study Chair: Carl Roobottom, BSc, MBChB(hon), MRCP. FRCR, University Hospital Plymouth NHS Trust; Principal Investigator: Srikanth Iyengar, MBBS, MS, FRCS, FRCR, University Hospital Plymouth NHS Trust

Study record dates

Study Major Dates

• Study Start: April 1, 2011
• Primary Completion (Actual): August 1, 2012
• Study Completion (Actual): August 1, 2012

Study Registration Dates

• First Submitted: September 3, 2013
• First Submitted That Met QC Criteria: September 16, 2013
• First Posted (Estimate): September 20, 2013

Study Record Updates

• Last Update Posted (Estimate): September 20, 2013
• Last Update Submitted That Met QC Criteria: September 16, 2013
• Last Verified: September 1, 2013

More Information

Terms related to this study

• Keywords: Performance; Diagnostic; Disease; Coronary; Artery; Angiography
• Additional Relevant MeSH Terms: Heart Diseases; Cardiovascular Diseases; Vascular Diseases; Arteriosclerosis; Arterial Occlusive Diseases; Coronary Artery Disease; Myocardial Ischemia; Coronary Disease
• Other Study ID Numbers: 11/P/050; 11/H0206/5 (Other Identifier: UK REC Reference Number)