Consensus document on the clinical application of invasive functional coronary angiography from the Japanese Association of Cardiovascular Intervention and Therapeutics

Abstract

Invasive functional coronary angiography (FCA), an angiography-derived physiological index of the functional significance of coronary obstruction, is a novel physiological assessment tool for coronary obstruction that does not require the utilization of a pressure wire. This technology enables operators to rapidly evaluate the functional relevance of coronary stenoses during and even after angiography while reducing the burden of cost and complication risks related to the pressure wire. FCA can be used for treatment decision-making for revascularization, strategy planning for percutaneous coronary intervention, and procedure optimization. Currently, various software-computing FCAs are available worldwide, with unique features in their computation algorithms and functions. With the emerging application of this novel technology in various clinical scenarios, the Japanese Association of Cardiovascular Intervention and Therapeutics task force was created to outline expert consensus on the clinical use of FCA. This consensus document advocates optimal clinical applications of FCA according to currently available evidence while summarizing the concept, history, limitations, and future perspectives of FCA along with globally available software.Graphical abstractOverview and proposed clinical applications of functional coronary angiography (FCA). The FCA was developed according to computed fluid dynamics (CFD), considering the pressure drop across the coronary stenosis. CFD analysis was performed with a three-dimensional coronary model derived from angiography, allowing the calculation of the physiological index without the use of a pressure wire. Another direction of development in FCA is using artificial intelligence throughout the entire process, enabling “hands-free” FFR simulation. The advantage of the FCA is that it eliminates the use of a pressure wire, resulting in reduced invasiveness, shorter procedure times, and reduced medical costs. However, FCA requires high-quality angiography for a clear visualization of the lesion. In addition, the current version of FCA requires several manual corrections; thus, its reproducibility is limited. Further data on clinical outcomes after the use of FCA, such as percutaneous coronary intervention (PCI) with FCA guidance, are warranted. The consensus group of the Japanese Association of Cardiovascular Intervention and Therapeutics proposed the application of FCA in various clinical scenarios considering the advantages of this technology. QFR, quantitative flow ratio; iFR, instantaneous wave-free ratio; CCS, chronic coronary syndrome; ACS, acute coronary syndrome; MVD, multivessel disease; AMI, acute myocardial infarction.