OBJECTIVES: The early identification of coronary artery disease CAD is important in preventing subsequent premature mortality and disability, and potentially reducing the healthcare burden associated with advanced disease. The objective of this study was to evaluate the cost-effectiveness of myocardial perfusion scintigraphy (MPS) for patients with suspected chronic CAD in the UK. METHODS: A decision-analytic model was developed to represent the diagnosis and management of patients with suspected XCAD. A 'diagnostic' module represented alternative diagnostic strategies based on combinations of exercise ECG (ExECG), MPS and coronary angiography (CA). A 'treatment' module represented initial patient management, based on diagnostic results. Finally, subsequent patient experience (mortality, future MIs and revascularisation procedures) according to severity of disease and therapy at outset was represented as a Markov process. Event risks, therapy effectiveness (risk reductions), diagnostic accuracy and risks were obtained from published studies. Test and intervention costs were based on NHS reference values. Long-term costs of patient management for patients with CAD in the UK, and health state utilities were based on published values. The model was used to test parameter assumptions, including duration of therapy effectiveness (base case: 5-10 years) and delay to diagnosis of false negatives (those missed in initial work-up: base case 1 year). Preliminary RESULTS: Compared with ExECG, MPS was cost-effective when the underlying risk of CAD was <50% (cost saving at <30%). Compared with a strategy of no testing MPS was cost-effective at an underlying risk of >20%. At =80% risk direct CA was cost saving and more effective than alternative diagnostic strategies. Adding MPS as a second-line test for patients positive or indeterminate on ExECG was cost-effective for intermediate risk patients. CONCLUSION: MPS is likely to be an economically attractive first-line or second-line test in the diagnostic work-up of symptomatic patients with intermediate risk of chronic CAD.