Comparing downstream consequences of normal exercise stress echocardiograms and cardiac computed tomography angiography scans in patients suspected of having of obstructive coronary artery disease: a retrospective cohort study of Tricare beneficiaries

To compare overall number of downstream tests and total costs between negative exercise stress echocardiograms (ESE) or cardiac computed tomography angiography scans (CCTA) in symptomatic Tricare beneficiaries suspected of having coronary artery disease (CAD). This is a retrospective cohort study examining 651 propensity-matched patients who underwent ESE or CCTA with normal results between 2008 and 2014 at the United States’ largest Department of Defense hospital. The total number of additional downstream tests over the next five years was determined. The total costs associated with each arm, inclusive of the initial test and all subsequent tests, were calculated using the 2018 Medicare Physician Fee Schedule. 18.5 percent of patients with a normal ESE result underwent some additional form of cardiac testing over the five years after initial testing compared to 12.8 percent of patients with a normal CCTA. The absolute difference in total number of downstream tests between both study groups was 5.7 percent (p = 0.03). When factoring the costs of the initial test as well as the downstream tests, the ESE group was associated with overall lower costs compared to the CCTA group, 351 United States Dollars (USD) versus 496 USD (p < 0.0001). This study demonstrates that, when compared to CCTA, ESE is associated with a higher total number of downstream tests, but overall lower total costs when chosen as initial testing strategy for suspected CAD.