Cost-effectiveness analysis of stand-alone or combined non-invasive imaging tests for the diagnosis of stable coronary artery disease: results from the EVINCI study

Abstract

Aim: This study aimed at evaluating the cost-effectiveness of different non-invasive imaging-guided strategies for the diagnosis of obstructive coronary artery disease (CAD) in a European population of patients from the Evaluation of Integrated Cardiac Imaging in Ischemic Heart Disease (EVINCI) study.

Methods and results: Cost-effectiveness analysis was performed in 350 patients (209 males, mean age 59 ± 9 years) with symptoms of suspected stable CAD undergoing computed tomography coronary angiography (CTCA) and at least one cardiac imaging stress-test prior to invasive coronary angiography (ICA) and in whom imaging exams were analysed at dedicated core laboratories. Stand-alone stress-tests or combined non-invasive strategies, when the first exam was uncertain, were compared. The diagnostic end-point was obstructive CAD defined as > 50% stenosis at quantitative ICA in the left main or at least one major coronary vessel. Effectiveness was defined as the percentage of correct diagnosis (cd) and costs were calculated using country-specific reimbursements. Incremental cost-effectiveness ratios (ICERs) were obtained using per-patient data and considering "no-imaging" as reference. The overall prevalence of obstructive CAD was 28%. Strategies combining CTCA followed by stress ECHO, SPECT, PET, or stress CMR followed by CTCA, were all cost-effective. ICERs values indicated cost saving from - 969€/cd for CMR-CTCA to - 1490€/cd for CTCA-PET, - 3092€/cd for CTCA-SPECT and - 3776€/cd for CTCA-ECHO. Similarly when considering early revascularization as effectiveness measure.

Conclusion: In patients with suspected stable CAD and low prevalence of disease, combined non-invasive strategies with CTCA and stress-imaging are cost-effective as gatekeepers to ICA and to select candidates for early revascularization.

Keywords: Angiography; Coronary artery disease; Coronary computed tomography; Cost-effectiveness; Economic; Invasive coronary angiography; Stress-imaging.

Fig. 1

Each single or combined imaging strategy was defined as positive or negative as schematically shown

Fig. 2

Differences in mean cost and in mean effectiveness (with relative contour plots representing confidence intervals obtained from bootstrap analysis) are plotted in four different cost-effectiveness planes allowing comparison of self-standing CTCA, one stress-imaging and their combinations

Fig. 3

Differences in mean cost and in mean effectiveness (with relative contour plots representing confidence intervals obtained from bootstrap analysis) are plotted in cost-effectiveness planes allowing comparison of self-standing CTCA, CMR and their combinations in different countries

Fig. 4

Differences in mean cost and in mean effectiveness (with relative contour plots representing confidence intervals obtained from bootstrap analysis) are plotted in cost-effectiveness planes allowing comparison of self-standing CTCA, ECHO and their combinations in different countries

Fig. 5

Differences in mean cost and in mean effectiveness (with relative contour plots representing confidence intervals obtained from bootstrap analysis) are plotted in cost-effectiveness planes allowing comparison of self-standing CTCA, SPECT and their combinations in different countries

Fig. 6

The diagnostic and therapeutic yield of invasive angiography, if indicated on the basis of non-invasive imaging strategies (without distinction among stress modalities) involving CTCA, Stress tests or combination of in different order (CTCA > stress and stress > CTCA). For comparison, the same figures are obtained when all patients would are referred directly to ICA