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Figure 3 Mechanisms of late stent thrombosis in ostial and bifurcation stenting. (A to D) Radiograph and histologic sections (Movat pentachrome) from a 77-year-old man who had two stents placed in the native left anterior descending coronary artery (LAD) for stable angina 450 days before sudden cardiac death. (A) Radiograph of the LAD with two stents in place, a proximal Cypher and a distal bare-metal stent (NIR). The Cypher stent struts (*) protrude into the ostium of the left circumflex artery (LCx). (B) Section taken from the proximal Cypher stent, which is totally occluded by a platelet-rich thrombus while distally it is patent (C) with minimal neointimal tissue. The NIR stent (D) in the distal LAD demonstrates 50% in-stent area stenosis consisting of neointimal tissue composed of smooth muscle cells in a proteoglycan/collagen matrix with absence of fibrin. (E to H) Radiographs and histologic sections (Movat pentachrome) from a 68-year-old black woman with a history of stenting of the LCx and left obtuse marginal (LOM) using the crush technique (Taxus to LCx and Cypher to LOM) 172 days before death. She presented 2 days before her death with acute myocardial infarction and was taken to the catheterization laboratory, where 90% occlusion of the LCx near the LOM take-off was found. The LCx artery was opened with balloon angioplasty, but the patient died of complications shortly thereafter. (E) Cypher struts within LOM and fracture of the Taxus stent after the LOM take-off. Histologic sections taken proximal to the bifurcation (F) and at the LCx/LOM bifurcation (G) show thrombus (Th) in the LCx (Taxus), whereas the Cypher stent is covered by neointimal growth. Two struts with overlying thrombus are shown at high power in H. Note the absence of neointimal coverage of the Taxus struts with overlying thrombus.
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