title: Possible role of damaged neoendothelial cells in the genesis of coronary stent thrombus in chronic phase. A dye staining angioscopic study.
abstract: The mechanism(s) underlying formation of coronary stent thrombus (ST) in chronic phase is yet unclear. Endothelial cells are highly antithrombotic, therefore, it is conceivable that neoendothelial cells (NECs) covering stent struts are damaged and cause ST. This study was performed to examine the role of damaged NECs covering coronary stent struts in the genesis of occlusive or nonocclusive ST in chronic phase.(1) Forty-four patients with acute coronary syndrome (17 females and 27 males) underwent dye-staining coronary angioscopy, using Evans blue which selectively stains damaged endothelial cells, 6 months after bare-metal stent (BMS) deployment. Neointimal coverage was classified into not covered (grade 0), covered by a thin layer (grade 1), and buried under neointima (grade 2) groups. (2) In 7 beagles, the relationships between neointimal thickness and ST were examined 6 months after BMS deployment. (3) The NECs on the struts were stained blue in 4 of 25 patients with grade 2 and in 11 of 20 patients with grade 0/1 (P < 0.05). ST was observed in none of the former and in 5 of the latter (P < 0.05). (4) In beagles, neointimal coverage was grade 0/1 when neointimal thickness was 80.2 ± 40.0 µm, whereas grade 2 when thickness was 184 ± 59.4 µm. ST was observed in 9 of 15 struts with neointimal thickness within 100 µm and in one of 17 struts with thickness over 100 µm (P < 0.05). ST arose from damaged NECs covering the stent struts. NECs may have been damaged due to friction between them and struts due to thin interposed neointima which might have acted as a cushion, resulting in ST.
authors.affiliation: Japan Foundation for Cardiovascular Research, Chiba, Japan.
authors.forename: Yasumi
authors.initials: Y
authors.lastname: Uchida
authors.forename: Yasuto
authors.initials: Y
authors.lastname: Uchida
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sakurai
authors.forename: Masahito
authors.initials: M
authors.lastname: Kanai
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Shirai
authors.forename: Tomomitsu
authors.initials: T
authors.lastname: Oshima
authors.forename: Atsushi
authors.initials: A
authors.lastname: Koga
authors.forename: Akimasa
authors.initials: A
authors.lastname: Matsuyama
mesh_terms: D054058:Acute Coronary Syndrome / Q000209:etiology / Q000473:pathology / Q000628:therapy*; D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D017546:Angioscopy; D004396:Coloring Agents; D023903:Coronary Restenosis / Q000209:etiology* / Q000473:pathology* / Q000517:prevention & control; D054855:Drug-Eluting Stents / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058426:Neointima / Q000473:pathology*; D012189:Retrospective Studies; D015607:Stents / Q000009:adverse effects*; D013997:Time Factors
chemical_list: D004396:Coloring Agents