It’s good news this week for some of the biggest medical imaging companies
GE Healthcare, Siemens Healthcare, Philips Healthcare and Toshiba Medical Systems – with all four receiving tentative backing for their respective next-generation cardiac CT scanners in draft guidance drawn up by the National Institute for Health and Clinical Excellence (NICE) in its latest draft guidance on the subject.
Now available for a period of public consultation, the draft guidance specifically applies to the use of the Somatom Definition Flash CT scanner (Siemens), Aquilion One (Toshiba), Brilliance iCT (Philips) and Discovery CT750 (GE) 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. A review team looked at 24 studies, with the vast majority (20) using Siemens’ Somatom Definition Flash (1) or an earlier model, Somatom Definition (19). Interestingly, despite its glowing endorsement only two of the studies referenced actually used the cutting edge CT scanner technology. In 2007, CAD was estimated to have claimed 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. The technology survived a review of five recognised models for assessing the cost effectiveness of next-generation cardiac CT scanners, including the Europa model, for the prognosis of people with CAD, and the York Radiation Model, which estimates the impact of imaging in terms of radiation dose on cancer mobidity and mortality.
The recent NICE clinical guideline on chest pain recommends CT coronary angiography and invasive coronary angiography to assess the state of arteries and identify significant narrowing in people with an estimated probability of coronary artery disease of 10 to 29 per cent and a calcium score of <400 or less. People with a calcium score >400 are considered difficult to image using earlier generation CT technologies. Other reasons that make CT imaging difficult are obesity, arrhythmias (irregular heart beat), high heart rates (above 70 beats per minute) or previous coronary stents or bypass grafts.
The latest generation cardiac CT scanners have technical features that aim to overcome these difficulties, including the ability to acquire images much faster than earlier generation CT scanners, better image quality and reduced radiation doses. The NICE guidance recommends the use of these scanners for first line imaging of the coronary arteries in people with suspected stable coronary artery disease who are difficult to image with earlier generation CT scanners and whose estimated probability of having CAD is 10 to 29 per cent. In addition, the draft guidance recommends their use in people with known CAD for first line evaluation of disease progression to establish the need for revascularisation where imaging with earlier generation CT scanners is difficult.
Imaging companies will not quite be celebrating at the moment as final guidance on this topic is not expected until the new year, but they will be quietly confident that there is now a recognised need for the technology within the National Health Service in the UK.