Effectiveness and costs of different strategies for the diagnosis of stable coronary artery disease: results from the EVINCI study

OBJECTIVES: The analysis of different non-invasive imaging strategies in a European population of patients with stable angina could help the identification of the best approach for the diagnosis of significant CAD. METHODS: In 475 pts (291 males, 60±9 yrs) with stable angina enrolled in the EVINCI multicenter study, CT coronary angiography (CTCA) and stress imaging were performed before invasive coronary angiography (ICA). Significant CAD was defined as >50% stenosis in the left main or >70% stenosis in a major coronary vessel or 30-70% stenosis with fractional flow reserve ≤0.8. Nine non-invasive imaging strategies including CTCA or stress imaging (ECHO, CMR, SPECT or PET) alone or in combination with CTCA performed as first line examinations were evaluated. Combinations were positive if both CTCA and the stress test were positive and their performance was evaluated in terms of accuracy (AUC). Centres specific reimbursements were collected for invasive and non-invasive examination and the costs associated with different strategies were obtained at individual patient level by summing up reimbursement of the examinations involved. RESULTS: Significant CAD was diagnosed at ICA in 140 patients (29%). CTCA had the highest diagnostic performance among strategies involving single imaging modalities [0.91(0.88-0.94)] and CTCA-PET among combinations [0.84(0.74-0.93)]. Costs vary significantly among the strategies involving single non invasive modalities with value ranging from 425 Euro for ECHO to 1245 Euro for PET as well as for those involving combinations of imaging modalities ranging from 508 Euro for CTCA-ECHO to 870 Euro for CTCA-SPECT CONCLUSIONS: The diagnostic workflow for CAD detection shows variable effectiveness and costs according to the use of different single or combined non invasive imaging modalities. Data collected in the EVINCI study offer the opportunity to evaluate several diagnostic workflows from a combined clinical and economic perspective using a cost-effectiveness analysis.