Myocardial perfusion scintigraphy: the evidence

This review summarises the evidence for the role of myocardial perfusion scintigraphy (MPS) in patients with known or suspected coronary artery disease. It is the product of a consensus conference organised by the British Cardiac Society, the British Nuclear Cardiology Society and the British Nuclear Medicine Society and is endorsed by the Royal College of Physicians of London and the Royal College of Radiologists. It was used to inform the UK National Institute of Clinical Excellence in their appraisal of MPS in patients with chest pain and myocardial infarction. MPS is a well-established, non-invasive imaging technique with a large body of evidence to support its effectiveness in the diagnosis and management of angina and myocardial infarction. It is more accurate than the exercise ECG in detecting myocardial ischaemia and it is the single most powerful technique for predicting future coronary events. The high diagnostic accuracy of MPS allows reliable risk stratification and guides the selection of patients for further interventions, such as revascularisation. This in turn allows more appropriate utilisation of resources, with the potential for both improved clinical outcomes and greater cost-effectiveness. Evidence from modelling and observational studies supports the enhanced cost-effectiveness associated with MPS use. In patients presenting with stable or acute chest pain, strategies of investigation involving MPS are more cost-effective than those not using the technique. MPS also has particular advantages over alternative techniques in the management of a number of patient subgroups, including women, the elderly and those with diabetes, and its use will have a favourable impact on cost-effectiveness in these groups. MPS is already an integral part of many clinical guidelines for the investigation and management of angina and myocardial infarction. However, the technique is underutilised in the UK, as judged by the inappropriately long waiting times and by comparison with the numbers of revascularisations and coronary angiograms performed. Furthermore, MPS activity levels in this country fall far short of those in comparable European countries, with about half as many scans being undertaken per year. Currently, the number of MPS studies performed annually in the UK is 1,200/million population/year. We estimate the real need to be 4,000/million/year. The current average waiting time is 20 weeks and we recommend that clinically appropriate upper limits of waiting time are 6 weeks for routine studies and 1 week for urgent studies.Abbreviations Acc Diagnostic accuracy - ACS Acute coronary syndromes - BCS British Cardiac Society - BNCS British Nuclear Cardiology Society - BNMS British Nuclear Medicine Society - CABG Coronary artery bypass grafting - CHD Coronary heart disease - CT Computed X-ray tomography - LBBB Left bundle branch block - MI Myocardial infarction - MIBI Technetium-99m 2-methoxy-isobutyl-isonitrile - MPS Myocardial perfusion scintigraphy - NSF National Service Framework for Cardiovascular Disease - NSTEMI Non-ST segment elevation myocardial infarction - PCI Percutaneous coronary intervention - Q Quantitative analysis - QALY Quality-adjusted life-year - RCP Royal College of Physicians of London - RCR Royal College of Radiologists - Sens Sensitivity - Spec Specificity - SPET Single-photon emission tomography - STEMI ST segment elevation myocardial infarction - Tetro or tetrofosmin Technetium-99m 1,2-bis[bis(2-ethoxyethyl) phosphino] ethane - 201Tl or thallium Thallium-201 thallous chloride - UA Unstable angina - V Visual analysis