Multicenter Registry for Angiography-Derived Quantitative Flow Ratio

Despite potential clinical benefits and abundant evidences of FFR-guided percutaneous coronary intervention (PCI), adoption rate of FFR is still low in real world practice, most likely due to use of additional resource and to concern about side effects of hyperemic agent. Therefore, several tools to derive FFR non-invasively has been developed based on computational fluid dynamics to overcome the limitations. One of the novel methods, the contrast quantitative flow ratio (QFR) is a computation of FFR based on 3-dimensional quantitative coronary angiography (QCA) combined with Thrombolysis in Myocardial Infarction (TIMI) frame counts adjustment without hyperemic agent infusion. Although diagnostic performance of contrast QFR for evaluation of functional significance, using FFR as reference standard, is well validated in patients with stable ischemic heart disease (SIHD), there have been lack of evidence regarding the reliability of QFR for non-culprit stenosis in patients with AMI. Therefore, the investigators sought to investigate the feasibility and diagnostic performance of contrast QFR for identifying the functional significance of coronary stenosis in all-comer patients with CAD. In addition, prognostic implication of contrast QFR will be also compared with that of FFR.