title: Characterization of coronary fibrin thrombus in patients with acute coronary syndrome using dye-staining angioscopy.
abstract: OBJECTIVE
  Because fibrin is transparent and almost invisible by any conventional imaging methodologies, clinical examinations of coronary fibrin thrombus have been ignored, and little is known about its role in the genesis of acute coronary syndrome (ACS). The present study was performed to visualize coronary fibrin thrombus and to examine its role in ACS.
  
  
  RESULTS
  Dye-staining coronary angioscopy using Evans blue dye, which selectively stains fibrin blue but does not stain blood corpuscles, was performed for observation of globular coronary thrombi in 111 ACS patients. The thrombi were aspirated for histological examination. The thrombi were classified by visual appearance into 8 transparent, 3 light-red, 2 frosty glass-like and membranous, 32 white, 8 brown, 34 red, and 19 red-and-white in a mosaic pattern. Transparent thrombi that were not visible by conventional angioscopy were visualized as a blue structure by dye-staining angioscopy, and they were observed in patients with unstable angina (UA) and non-ST elevation myocardial infarction (NSTEMI). The thrombi caused total or subtotal coronary occlusion. The aspirated thrombi were composed of fibrin alone by histology. Fibrin-rich thrombi were visualized using dye-staining angioscopy in 60% of 50 patients with UA+NSTEMI and in 29% of 61 patients with ST-elevation myocardial infarction. By histology of the aspirated thrombi, fibrin-rich thrombi were observed in 71% of 33 patients with UA+NSTEMI and in 28% of 35 patients with ST-elevation myocardial infarction.
  
  
  CONCLUSIONS
  Fibrin-rich coronary thrombi were frequently observed by both dye-staining angioscopy and histology in ACS patients. Rarely, fibrin itself formed a globular thrombus and caused coronary occlusion.
authors.affiliation: Japan Foundation for Cardiovascular Research, Funabashi, Japan. uchiy@ta2.so-net.ne.jp
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: Toshihiro
authors.initials: T
authors.lastname: Morita
mesh_terms: D054058:Acute Coronary Syndrome / Q000209:etiology*; D000368:Aged; D017546:Angioscopy / Q000379:methods*; D004396:Coloring Agents; D003328:Coronary Thrombosis / Q000150:complications* / Q000175:diagnosis*; D005260:Female; D005337:Fibrin / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation
chemical_list: D004396:Coloring Agents; D005337:Fibrin