DOI: 10.6084/m9.figshare.29958005.v2
title: Cost savings from prioritization of non-invasive modalities within CAD diagnostic protocols: a systematic review

description: While the clinical benefits of non-invasive modalities to diagnose coronary artery disease (CAD) are well recognized, the economic implications of their use over invasive options remain unclear. This review aims to understand the health economic consequences of using non-invasive versus invasive modalities in symptomatic patients with low-to-intermediate pre-test probability (PTP) of CAD, and to explore whether economic and humanistic data can inform future investment decisions around non-invasive and invasive diagnostic modalities. We performed a systematic review of MEDLINE and Embase, MEDLINE In-process, the Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials. Studies from January 1992 to January 2023 were included, if they were based in the UK, France, Germany, Italy, Japan, China, and/or the USA (published in any language). Risk of bias was assessed using the Drummond checklist. We evaluated invasive techniques, including invasive catheterization angiography (ICA) and ICA with fractional flow reserve (ICA-FFR), as well as non-invasive modalities, including coronary computerized tomography angiography (CCTA), CCTA-FFR, cardiovascular magnetic resonance (CMR), stress electrocardiogram, myocardial perfusion scintigraphy-single photon emission computed tomography, positron emission tomography, and stress echocardiography. Thirty-nine unique records reported relevant outcomes and were fully extracted. In patients with a low-to-intermediate PTP of CAD, most of the comparisons of non-invasive modalities followed or not by confirmatory ICA imaging, versus ICA demonstrated cost savings. The use of non-invasive modalities, followed or not followed by confirmatory ICA, was reported to reduce the number of revascularizations and length of hospital stays, versus ICA alone. This study suggests that investment in CAD diagnosis should prioritize the use of CCTA and CMR imaging over ICA and other non-invasive modalities. Doctors choose imaging tests to diagnose patients who might have coronary heart disease based on whether they have a low, intermediate or high chance of having the disease. This chance is called a patient’s “pre-test probability.” There are invasive and non-invasive imaging tests. Non-invasive tests are often recommended before invasive tests, particularly for patients with a low or intermediate pre-test probability. However, we do not know the cost implications of choosing non-invasive tests first. We searched for studies published between 1992 and 2023 that compared the use of non-invasive tests with one kind of invasive test, called invasive coronary angiography. We were interested in studies that described the value of using non-invasive tests in terms of quality of life, healthcare costs and other kinds of value. We found 39 studies published between 1997 and 2022. Most compared using two tests—a non-invasive test followed by an invasive test—with using only an invasive test. We looked at the results in patients with a low or intermediate pre-test probability. Studies often found that, in these patients, a non-invasive test (before or instead of an invasive test) was better value than an invasive test alone. With non-invasive tests, patients needed fewer medical procedures or days in the hospital. Our results show that patients should receive non-invasive imaging before invasive imaging is considered. Therefore, more funding should go to non-invasive imaging.