title: The possibility of delayed arterial healing 5 years after implantation of sirolimus-eluting stents: serial observations by coronary angioscopy.
abstract: BACKGROUND
  Although very late stent thrombosis occurs several years after implantation of sirolimus-eluting stent (SES), the morphologic changes of the stent beyond 2 years have not yet been systematically studied in living patients. The late vascular response to SES was therefore evaluated by serial angioscopic studies at 2 and 5 years after stent implantation.
  
  
  METHODS
  A total of 17 patients with 17 SES underwent a repeated angioscopy procedure at 2 and 5 years. Neointimal stent coverage (NSC) was classified as follows: grade 0, presence of uncovered struts; grade 1, visible struts through a thin neointima; or grade 2, complete neointimal coverage without visible struts. For each patient, the minimum and maximum NSC grade and the existence of in-stent thrombus were recorded.
  
  
  RESULTS
  The minimum and maximum NSC grade did not increase between the 2 and 5 years (0.59 ± 0.51 vs 0.88 ± 0.70, P = .17, and 1.82 ± 0.39 vs 1.94 ± 0.24, P = .30, respectively). The prevalence of patients with uncovered struts did not significantly decrease from 2 to 5 years (41% vs 29%, P = .49). During the follow-up period, 3 of 6 thrombi disappeared, whereas new thrombus formation was found in 3 patients without any clinical symptoms. In-stent thrombus did not decrease (35% vs 35%, P > .99).
  
  
  CONCLUSIONS
  The current serial angioscopic study suggests that incomplete NSC and the prevalence of latent thrombus within the SES segments did not decrease from 2 to 5 years. The risk of stent thrombosis related to incomplete healing of SES may continue for an extended period.
authors.affiliation: Cardiovascular Center, Chiba-Hokusoh Hospital, Nippon Medical School, 1715 Kamakari, Inzai, Chiba, 270-1694, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Masamichi
authors.initials: M
authors.lastname: Takano
authors.forename: Daisuke
authors.initials: D
authors.lastname: Murakami
authors.forename: Toru
authors.initials: T
authors.lastname: Inami
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Kobayashi
authors.forename: Sigenobu
authors.initials: S
authors.lastname: Inami
authors.forename: Kentaro
authors.initials: K
authors.lastname: Okamatsu
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Ohba
authors.forename: Chikao
authors.initials: C
authors.lastname: Ibuki
authors.forename: Noritake
authors.initials: N
authors.lastname: Hata
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Seino
authors.forename: Ik-Kyung
authors.initials: IK
authors.lastname: Jang
authors.forename: Kyoichi
authors.initials: K
authors.lastname: Mizuno
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D017546:Angioscopy; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000628:therapy; D003328:Coronary Thrombosis / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control; D003331:Coronary Vessels / Q000473:pathology*; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D058426:Neointima / Q000175:diagnosis / Q000453:epidemiology*; D015641:Radiography, Interventional; D020123:Sirolimus / Q000008:administration & dosage; D015607:Stents; D013997:Time Factors
chemical_list: D007166:Immunosuppressive Agents; D020123:Sirolimus