Resource and OUTcome Impact of routiNE availability of Computed Tomography Perfusion

AIMS: Stress computed tomography perfusion (Stress-CTP) is a functional technique added on top of coronary computed tomography angiography (cCTA) to improve the management of subjects with coronary artery disease (CAD). The ROUTINE-CTP Registry is a prospective study aimed at evaluating the impact of routine implementation of combined cCTA plus Stress-CTP for the assessment of patients with intermediate to high CAD risk or known CAD symptomatic for chest pain in a real-world setting. METHODS AND RESULTS: Data collected during follow-up included radiation exposure, reclassification rates between cCTA alone and cCTA with Stress-CTP, subsequent non-invasive testing, referral rates for invasive coronary angiography (ICA), prevalence of non-obstructive CAD at ICA, rates of revascularization, and major adverse cardiac events (MACE). Two hundred and sixty-three consecutive patients participated in the study (mean age of 65 ± 9 years, 79% male), of whom 156 (59%) had undergone previous revascularization. The evaluability rates for cCTA and Stress-CTP were 95 and 99%, respectively. Patients with functionally significant CAD experienced more downstream invasive testing and revascularization (P < 0.001), inducible ischaemia resulted the main independent predictor of revascularization (heart rate 20.08), and no coronary-related MACE occurred in the subset of patients with obstructive CAD and the absence of inducible ischaemia. CONCLUSION: The presence of inducible ischaemia at stress-CTP resulted the main predictor of coronary revascularization, while the absence of perfusion defects allowed to safely deferred further testing or invasive evaluation. This approach demonstrated a higher diagnostic yield in identifying individuals at lower risk of adverse events despite the presence of obstructive CAD.