Computed tomography-based fractional flow reserve (FFR-CT) – an attractive concept, but still lacking proof of clinical utility.

In initial studies, including the DISCOVER-FLOW and DeFACTO trial, the system was calibrated and compared against invasive FFR. The data demonstrated that the addition of FFRCT to CTA alone led to improved identification of ischemiainducing coronary lesions (FFR ≤0.8).6,7 The study primary n this issue of the Journal, Miyoshi et al describe their results from a subset of Japanese patients in a clinical trial examining the diagnostic performance of computed tomography-based fractional flow reserve (FFR-CT).1 FFRCT is a fascinating concept, applying computational fluid dynamics to computed tomographic angiography (CTA) images to in order to predict the hemodynamic significance of coronary lesions.2,3 Interestingly, a similar approach has recently been described that is based on 3D angiographic images obtained at rest and after induced hyperemia (Figure).4 In contrast to invasive FFR5 and 3D angiography-derived FFR,4 which use adenosine-induced hyperemia, FFR-CT is derived from anatomic images acquired at rest only, with subsequent mathematically simulated hyperemia. The analysis is based on I