This study has several important limitations. First, this study is a simulation of possible costs and outcomes rather than documentation of costs incurred and outcomes experienced utilizing FFR
CT in actual clinical practice. While direct assessment of cost-efficacy is not yet available for FFR
CT or other non-invasive testing modalities in stable CAD, the source data for this study represents the largest clinical experience of any non-invasive testing modality using FFR
cath as the reference standard. FFR
CT has close direct correlation to measured FFR, which has well-documented outcome and cost data in more than 1,005 patients [
11], but independent confirmation with actual outcome data utilizing FFR
CT for clinical decision making is needed. The extent to which patients analyzed in this report may not precisely reflect the spectrum of patients undergoing CAG in Japan may limit the ability to extrapolate directly to expected outcomes in Japan. A prospective longitudinal study evaluating clinical outcomes, resource utilization and quality of life of FFR
CT-guided evaluation and treatment of patients with suspected CAD is currently underway (PLATFORM trial, clinical trials.gov NCT01943903). Second, this study did not include patients with acute coronary ischemia, patients with prior PCI or CABG, and patients who are not suitable candidates for cCTA. Thus, the usefulness of FFR
CT in this broader population of patients with CAD is unknown. Third, costs related to clinical adverse events during follow-up were not considered; however, the FFR
CT guided pathway had the lowest event rate during follow-up. Fourth, FFR
CT is not yet widely available and market pricing for this test has not yet been determined. This analysis uses an FFR
CT price of $2,000, the price at which the costs of Pathways 2 and 4 were equivalent. The resulting average total cost of treating a patient in Pathway 4 (cCTA-FFR
CT-CAG) is $7,222. If the price of FFR
CT is modeled as $1,500, the average cost of treating a patient in this pathway decreases to $6,848, a 34 % savings compared to standard care (Pathway 1). If the price of FFR
CT is modeled as $2,500, the average cost for a patient in this pathway is $7,596, a 27 % reduction compared to standard care (Pathway 1). Finally, this analysis does not consider the possibility of only partial or limited adoption of the FFR
CT decision pathway, which inherently would limit the potential cost savings of this approach. For example, the decision to send a patient to CAG is made by comprehensive evaluation of the patient’s symptoms and physical findings, risk profile, and results of other non-invasive tests for myocardial ischemia and may cause the physician to override the results of the FFR
CT. Similarly, physicians in Pathway 2 may choose to—not measure FFR in the cath lab or may override the results of FFR
cath thus reducing the potential economic and outcome benefit. Thus, actual savings achieved may be limited by physicians’ adherence to the clinical decision making pathway. Further evaluations including prospective outcome studies are underway to better understand and quantify the potential clinical and economic improvements identified in this simulation.