Invasive FFR and Noninvasive CFR in the Evaluation of Ischemia: What Is the Future?

This review provides an integrative and forward-looking perspective on the gamut of coronary physiology for the diagnosis and management of atherosclerosis. Because clinical events serve as the ultimate gold standard, the future of all diagnostic tests, including invasive fractional flow reserve and noninvasive coronary flow reserve, depends on their ability to improve patient outcomes. Given the prominent role of acute coronary syndromes and invasive procedures in cardiology, we practically consider 2 broad categories of patients with coronary disease: acute and stable. For patients with acute coronary disease, coronary physiology may potentially refine treatment of the culprit lesion. For both patients with stable and acute nonculprit disease, reducing hard endpoints with revascularization potentially occurs at the severe end of the focal physiological spectrum, an area under-represented in existing trials. Nonepicardial disease and diffuse atherosclerosis remain underexplored aspects of coronary physiology for testing of novel treatments.