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Completed

NCT Number: NCT01816750

Cardiac GSI Feasibility Study

The recently introduced Computed tomography (CT) scanner, Discovery CT750 HD (GE Healthcare, Milwaukee), incorporates a battery of innovations aimed at improving diagnostic image quality, evaluating perfusion and assessing for scar, in an effort to address the current shortcomings of Computed tomographic coronary angiography (CTCA) in patients with significant coronary artery disease. The new scanner will use a novel method of scanning (Cardiac Gemstone Spectral Imaging - Cardiac GSI) and image reconstruction (Adaptive Statistical Iterative Reconstruction- ASIR) as opposed to standard definition 64-slice CT Multi-detector row computed tomography(MDCT)and Filtered Back Projection (FBP) used by the conventional CT scanners. The Cardiac GSI protocol enables the scanner to acquire images at two different x-ray energies almost simultaneously, which can be post-processed to selectively reduce beam hardening artefacts and delete materials with specific attenuating properties from the images, such as coronary calcium. ASIR offsets the potential increase in radiation dose required for Cardiac GSI scanning. This will potentially result in images of higher diagnostic quality with an equivalent or perhaps lower dose of radiation compared to present technology.

Furthermore, it is hypothesised that dual-energy acquisition may improve the accuracy of the assessment of perfusion.

Although initial in-vitro results are encouraging, this technology has not been rigorously assessed with regards to its feasibility and diagnostic quality, limiting its applicability in routine clinical practice. This assessment will require a trial comparing the accuracy of Cardiac GSI CTCA with that of Invasive coronary angiography (ICA) for anatomical assessment of stenosis, Myocardial Perfusion Imaging with Single Photon Emission Computed Tomography (MPI-SPECT) for assessment of perfusion and Cardiac Magnetic Resonance (CMR) for assessment of myocardial scar. We have designed a pilot study in this regard which will help us assess the feasibility of the scan protocol and provide data to power a larger study to assess the diagnostic remit of Cardiac GSI scanning in the assessment of patients with high-risk of significant coronary artery disease and myocardial scar.

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Key information

Conditions

High Risk of Significant Coronary Artery Disease Cardiovascular Diseases Coronary Disease Heart Diseases Myocardial Ischemia Vascular Diseases

Age range

50 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Plymouth Hospitals NHS Trust

Plymouth, Devon, PL6 8DH, United Kingdom

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Accuracy arm

  • Patients >50 years of age
  • Suspected or known coronary artery disease referred for ICA

Stress perfusion arm

  • Patients >50 years of age
  • Suspected or established coronary artery disease referred for MPI-SPECT for assessment of inducible ischaemia

Delayed enhancement arm

  • Patients >50 years of age
  • Referred for CMR for assessment of myocardial viability/scar

Exclusion criteria

Accuracy arm

  • Consent cannot be obtained
  • Patient BMI > 30 kg /m2
  • NYHA class III or IV heart failure
  • Chronic total occlusion of target epicardial coronary artery
  • Urgent revascularisation required
  • Allergy to iodinated contrast or previous contrast induced nephropathy
  • Intolerance or contraindication to beta-blockers
  • Uncontrolled heart rhythm disturbances
  • 2nd or 3rd degree atrioventricular block
  • Estimated glomerular filtration rate <30ml/min within two weeks prior to procedure or chronic renal failure on dialysis
  • Pregnancy

Stress perfusion arm

  • As above, plus:
  • Asthma (any) or intolerance to adenosine

Delayed enhancement arm

  • As for Accuracy arm

Treatment and study plan

Cardiac GSI

Device

A novel method of computed tomography scanning (Cardiac Gemstone Spectral Imaging - Cardiac GSI) and image reconstruction (Adaptive Statistical Iterative Reconstruction- ASIR.

Other names: Cardiac Gemstone Spectral Imaging

Primary outcomes

  1. Feasibility - Assessment of rates of recruitment, acceptability of the procedure to patients, ease of CT acquisition

    Time frame: 4 months

    Assessment of rates of recruitment, acceptability of the procedure to patients, ease of CT acquisition. This pilot study will add to this assessment with specific information about the diagnostic performance of the novel scanning technique:

    • Are images of sufficient quality to be diagnostic?
    • Is diagnosis likely to be non-inferior to current comparable techniques, sufficient to justify a formal study?

Secondary outcomes

  1. radiation burden of the Cardiac GSI techniques

    Time frame: 4 months

    The Discovery CT750 HD scanner uses a new image reconstruction technique called Adaptive Statistical Iterative Reconstruction (ASIR). ASIR uses more complex mathematical modelling for image reconstruction, thus reducing the need for statistical assumptions and reducing image noise and artefact. It also requires the less raw data and thus significantly less radiation dose. Studies suggest that using ASIR can achieve up to 40% dose reduction compared to Filtered Back Projection (FBP).

    However, the effect of ASIR and radiation dose reducing algorithms on image quality and accuracy has not been assessed and the difference in image quality and artefact suppression using the new technology remains to be established before its widespread dissemination into clinical practice.

Sponsors and collaborators

Lead sponsor

University Hospital Plymouth NHS Trust

Other

Registry information

Official study title

Pilot Study to Assess the Feasibility and Diagnostic Performance of Computed Tomographic Coronary Angiography Using Cardiac Gemstone Spectral Imaging (Cardiac GSI) in Patients With High-risk of Significant Coronary Artery Disease and Myocardial Scar

Important dates

Study start
2013
Primary completion
2016
Study completion
2016
First posted
Mar 22, 2013
Registry last updated
Oct 24, 2016

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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