Coronary flow reserve and fractional flow reserve

Coronary flow reserve (CFR) and fractional flow reserve (FFR) are two methods used to provide information for functional significance of coronary artery stenosis. Despite having some limitations, both parameters not only designate severity of stenosis but also provide prognostic information when they are used within appropriate indications. In this review, invasive CFR and FFR measurements were revisited in parallel to improvements in revascularization technologies, with an emphasis on their guiding role in borderline lesions.