Economic Analysis of the CADScor System for Ruling Out Coronary Artery Disease in England

BACKGROUND: Coronary artery disease (CAD) is the most common type of heart and circulatory disease and is the leading cause of death worldwide. The current diagnostic pathway can lead to patient complications and is also extremely costly. A new medical device, the CADScor System (Acarix AB), was developed for the acoustic detection of CAD before patients undergo invasive diagnostic procedures. OBJECTIVES: Our objective was to assess the cost utility of the CADScor System for the diagnosis of CAD at an early stage in the diagnostic testing pathway in England. METHODS: A two-part economic model, consisting of a decision tree and Markov model, was developed to consider the cost utility (cost per quality-adjusted life-year [QALY] gained) of introducing the CADScor System for the diagnosis of CAD. The decision tree component explored the short-term costs and diagnostic outcomes associated with introduction of the test compared with the existing testing pathway. A Markov model was developed to explore the longer-term health and economic implications of the condition and original diagnosis, with costs and health effects estimated over different time horizons. Parameter uncertainty was explored in deterministic and probabilistic sensitivity analyses. RESULTS: Base-case results indicated that the CADScor System would result in cost savings (- £131 per patient) and a marginal increase in QALYs (0.00001) over a 1-year time horizon. Probabilistic results indicated that the intervention had a > 99% probability of being cost effective at a willingness-to-pay threshold of £20,000 per QALY gained and 100% probability of being cost saving. Results from the deterministic sensitivity analyses indicated that variations in parameters related to the accuracy and cost of the CADScor System, and the prevalence of CAD, had the greatest impact on the overall results. The overall cost saving was estimated to be over £12.3 million per 100,000 eligible patient population. CONCLUSIONS: The CADScor System is a potentially cost-saving test for the diagnosis of CAD. When initiated before the use of non-invasive cardiac imaging tests such as computed tomography coronary angiography, the test reduced costs to the healthcare service over various time horizons.