It is well established that coronary angiography is frequently unable to adequately characterize the hemodynamic impact of coronary stenoses. In particular, percent stenosis does not predict or reliably relate to maximum flow capacity or coronary flow reserve (CFR). Studies have clearly demonstrated that the anatomical assessment of the hemodynamic significance of coronary stenoses determined by visual modalities such as coronary angiography or computed tomography coronary angiography (CTCA) does not correlate well with the functional assessment of FFR. It is plausible, therefore, that when epicardial vessels are targeted for revascularization based on percent stenosis, this intervention may not lead to a significant improvement in myocardial blood flow and in fact could be detrimental.