Impact of Plaque Components on Fractional Flow Reserve-Derived Computed Tomography in Severe Coronary Stenosis

Fractional flow reserve derived from computed tomography decreases across severe coronary stenosis. The diagnostic accuracy of fractional flow reserve-derived computed tomography is high for severe coronary stenosis. In this report, we present a case of no significant fractional flow reserve-derived computed tomography changes even in severe coronary stenosis. A 75-year-old man showed severe stenosis (85% diameter stenosis) in the distal segment of the right coronary artery on both computed tomography angiography and invasive coronary angiography. However, fractional flow reserve-derived from computed tomography showed no significant changes from the proximal (0.97) to the distal (0.95) segments despite the presence of severe stenotic lesion. This patient had different features including the presence of a large acute marginal branch and significantly lower plaque components in the stenotic lesion compared with another patient who had coronary stenosis in the same segment. A large bifurcation branch and/or proportion of plaque components can affect fractional flow reserve derived from computed tomography hemodynamics.