Fig. 4

Angiography and FFR after stent implantation. A stent was implanted from C to D. FFR was performed again. After maximal congestion with adenosine, the values of a and b were both 0.89 (normal value > 0.8), and the pressure at point C is 0.90, and the pressure at point D is 0.96. The pressure gradient of C–D zone is 0.07, and the pressure gradient of B–C zone is 0.01