Multiple non-invasive tests are performed as part of the standard protocol to diagnose CAD, but all are limited to either anatomical or functional assessments. FFRCT is a new non-invasive test that combines anatomical and functional characteristics based on the principles of invasive FFR. This study aims to evaluate the added value of FFRCT beyond the currently used tests.
Patients having the clinical suspicion of angina pectoris between 2010 and 2011 were included in this cross-sectional study. All underwent exercise stress electrocardiography (X-ECG), SPECT, CT coronary angiography (CCTA) and FFRCT as part of the Horoscope study. Invasive coronary angiography(ICA) and FFR were used as reference standard. Missing values were multiple imputed and five combined models mimicking the clinical workflow were fitted. The area under the receiver operating characteristic (AUROC) curve and Akaike Information Criteria (AIC) were used for comparison.
89 (44%) of the 202 patients included in the analysis had a FFR of =0.80, while positive tests were found for X-ECG, SPECT, CCTA and FFRCT in 41%, 47%, 53% and 50% of the cases. The model including pre-test-likelihood and X-ECG had an AUROC of 0.78 (AIC: 236), which significantly increases to 0.89 by adding SPECT (AIC: 170), to 0.87 by adding CCTA (AIC: 191), to 0.92 when adding FFRCT (AIC: 155) and to 0.94 when adding CCTA and SPECT(AIC:1 40).
This study shows adding FFRCT leads to an increased AUROC and a decreased AIC compared to the basic model. It therefore improves the diagnostic work-up beyond SPECT or CCTA alone in the diagnosis of CAD.