Role of coronary angiography MDCT in the clinical setting: changes of diagnostic workup and economic implications

Purpose: To assess the incremental value of MDCT- coronary angiography (MDCT-CA) in the diagnostic workup and cost management of patients with suspected coronary artery disease (CAD). Methods and Materials: 550 consecutive patients underwent MDCT-CA between 04/2008 and 07/2010. For each patient pre-test probability of CAD using Morise score was related to exercise test, MDCT-CA and CA. We calculated thereafter the incremental diagnostic value of stress test to MDCT-CA for each category of cardiovascular risk. The traditional diagnostic workup (without MDCT-CA) to the modified workup (with MDCT-CA) in terms of pre-test CAD probability\effectiveness and cost\effectiveness were compared. Results: The diagnostic performance of stress test had a sensitivity and specificity of 46.2% and 73.4% with PPV and NPV of 48 % and 72 %. MDCT-CA demonstrated a sensitivity of 100 %, a specificity of 94.7%, PPV of 96.7% and NPV of 100 %. According to Morise Score, in low pre-test probability, stress test accuracy resulted 30 %, in moderate pre-test 38 %, in high pre-test 45 % considering MDCT-CA as reference. The MDCT-CA modified diagnostic protocol offers an average increased diagnostic performance of 60 % compared with the traditional protocol, and an average cost saving of € 1323 per patient. Conclusions: MDCT-CA is the reference method for the non-invasive exclusion of critical coronary stenosis. Up to a low-medium CAD risk, the MDCT-CA diagnostic workup is the most cost-effective protocol, being superior to the traditional exercise ECG-based protocol.