Figure 4.

Mechanisms of stent thrombosis evaluated by intravascular imaging. A′-C′ are optical coherence tomography (OCT) or intravascular ultrasound (IVUS) images corresponding to stent thrombosis seen in the angiographic images A-C (white arrows). A″-C″ are representative diagrams provided to clarify the intracoronary images A′-C′. Top. Mechanisms of stent thrombosis evaluated by OCT (A) Subacute stent thrombosis in which OCT showed a severely underexpanded stent occupied by white thrombus in the mid left anterior descending artery. (B) Very late stent thrombosis occurred 2 hours after noncardiac surgery and after discontinuation of antiplatelet therapy. OCT showed uncovered stent struts occupied by white thrombus. (C) Lipidic plaque (strong signal attenuation) within stent struts indicating neoatherosclerosis resulting in plaque rupture with thrombus. Bottom. Mechanisms of stent thrombosis evaluated by IVUS (A) Subacute stent thrombosis in which IVUS showed a severely underexpanded stent and thrombus in the mid left circumflex artery. (B) Very late stent thrombosis in which IVUS showed a well-expanded stent occupied by thrombus. Because there is no neointimal hyperplasia, it was speculated that uncovered stent struts were the cause of stent thrombosis. (C) Lipidic plaque (strong signal attenuation) appeared within the stent struts indicating neoatherosclerosis resulting in plaque rupture with thrombus.