Guidance published today on four new generation cardiac computed tomography (CT) scanners supports their use in the NHS in England for people with suspected or known coronary artery disease (CAD) in whom imaging is difficult with earlier generation CT scanners.

The guidance, produced as part of NICE's diagnostics assessment programme, recommends Somatom Definition Flash CT scanner (Siemens AG Healthcare), Aquilion ONE (Toshiba Medical Systems), Brilliance iCT (Philips Healthcare) and Discovery CT750 (GE Healthcare) as options for first-line imaging of the coronary arteries in people with suspected stable CAD (with an estimated likelihood of coronary artery disease of 10-29%) and for first-line evaluation of disease progression to establish the need for revascularisation in people with known CAD in whom imaging with earlier generation CT scanners is difficult.[1]

CAD is a condition in which a plaque, made up of fat, cholesterol, calcium and other substances found in the blood, builds up inside the coronary arteries supplying oxygen-rich blood to the heart. Over time, the plaque hardens and narrows the coronary arteries, restricting the flow of oxygen-rich blood to the heart (ischaemia). Sometimes, an area of plaque can rupture, causing a blood clot to form on the surface of the plaque. If the clot becomes large enough, it can largely or completely block blood flow through a coronary artery causing a heart attack or angina. In 2007, CAD was estimated to have caused 91,000 deaths in the UK.

CT scans are performed to evaluate the arteries of the heart, and can also be used to assess the function of the heart, the anatomy of the heart, and the degree of coronary calcification in the heart. However, in some people, imaging the heart and surrounding blood vessels is difficult with older types of CT scanners. This can be due to a number of reasons, including obesity, levels of coronary calcium higher than 400 and heart rates greater than 65 beats per minute that cannot be lowered with drugs. New generation cardiac CT scanners have advantages over older types of CT scanners for these people because they can produce better images in a shorter time (within one or two heartbeats).

Professor Carole Longson, NICE Health Technology Evaluation Centre Director, said: "From a patient perspective, a non-invasive cardiac diagnostic test is more appealing than the current alternative for people in whom imaging is difficult - invasive coronary angiography - because of the greater morbidity and mortality risks associated with angiography. New generation cardiac CT was found to be more cost effective than angiography because of its lower imaging costs and the lower risk of adverse outcomes and associated reduced downstream healthcare costs from dealing with complications. The independent Diagnostics Advisory Committee concluded that the evidence presented indicated that new generation cardiac CT was more cost effective for people in whom imaging is difficult than proceeding directly to invasive angiography. Service providers in England, working with commissioners and cardiac networks, should take into account the benefits of new generation cardiac CT scanners for use in the circumstances described in this guidance when selecting CT scanners as part of medium term asset planning."

Read the diagnostics guidance for CT scanners for cardiac imaging.

Ends

Notes to Editors

About the guidance

1. Professor Adrian Newland, Chair of the independent Diagnostics Advisory Committee, said: "For patients with coronary artery disease who are difficult to image the current options for assessment are associated with increased morbidity and mortality. The new generation of CT scanners have a number of features that offer genuine improvements in assessment in these patients. Our evaluation confirmed not only the cost effectiveness of the technique but also its clinical benefits. We hope this guidance can be used for planning the development of facilities for the first-line imaging of this difficult to image group with suspected stable CAD, and for first-line evaluation of those with disease progression who may require revascularisation."

2. Because earlier generation CT scanners are not considered viable for imaging some people, the comparator used in this assessment is invasive coronary angiography. Invasive coronary angiography uses a contrast dye and X-rays to provide anatomical information about the degree of stenosis in the coronary arteries. A catheter is generally inserted into an artery in the groin or wrist and is moved up the aorta and into the coronary arteries. Once in place, the dye is injected through the catheter, and a rapid series of X-ray images is taken to show how the dye moves through the branches of the coronary arteries. Any narrowing of the arteries will show up on the X-ray images.

3. Invasive coronary angiography is considered the reference standard for providing anatomical information and defining the site and severity of coronary artery lesions. Some rare but serious complications include death, myocardial infarction, cerebrovascular accident, arrhythmia, vascular complications, allergic reaction to contrast media, haemodynamic complications and perforation of the heart chamber.

4. In addition to people with known or suspected coronary artery disease, children and adults with congenital heart disease were also identified during scoping for this topic as being potentially the most likely to benefit from new generation cardiac CT scanners. However, during the assessment phase, no evidence was found on the use of new generation cardiac CT scanners in this population. Consequently, the Diagnostic Advisory Committee did not make recommendations for this population, and reference to it has been removed from the Diagnostic Consultation and Guidance Documents. The title of both these documents has also been updated to reflect the patient population to which they apply.

About the NICE Diagnostics Assessment Programme

5. Further information about the NICE diagnostics assessment programme can be found at: www.nice.org.uk/diagnostics

6. Topics to be considered by the Programme are routed through the related Medical Technologies Assessment Programme. Further information about this can be found at: www.nice.org.uk/mt

About NICE

7. The National Institute for Health and Clinical Excellence (NICE) is the independent organisation responsible for providing national guidance and standards on the promotion of good health and the prevention and treatment of ill health.

8. NICE produces guidance in three areas of health:

• public health - guidance on the promotion of good health and the prevention of ill health for those working in the NHS, local authorities and the wider public and voluntary sector
• health technologies - guidance on the use of new and existing medicines, treatments, medical technologies (including devices and diagnostics) and procedures within the NHS
• clinical practice - guidance on the appropriate treatment and care of people with specific diseases and conditions within the NHS.

9. NICE produces standards for patient care:

• quality standards - these reflect the very best in high quality patient care, to help healthcare practitioners and commissioners of care deliver excellent services
• Quality and Outcomes Framework - NICE develops the clinical and health improvement indicators in the QOF, the Department of Health scheme which rewards GPs for how well they care for patients

10. NICE provides advice and support on putting NICE guidance and standards into practice through its implementation programme, and it collates and accredits high quality health guidance, research and information to help health professionals deliver the best patient care through NHS Evidence.