title: Pathology of second-generation everolimus-eluting stents versus first-generation sirolimus- and paclitaxel-eluting stents in humans.
abstract: BACKGROUND
  Clinical trials have demonstrated that the second-generation cobalt-chromium everolimus-eluting stent (CoCr-EES) is superior to the first-generation paclitaxel-eluting stent (PES) and is noninferior or superior to the sirolimus-eluting stent (SES) in terms of safety and efficacy. It remains unclear whether vascular responses to CoCr-EES are different from those to SES and PES because the pathology of CoCr-EES has not been described in humans.
  
  
  RESULTS
  A total of 204 lesions (SES=73; PES=85; CoCr-EES=46) from 149 autopsy cases with duration of implantation >30 days and ≤3 years were pathologically analyzed, and comparison of vascular responses was corrected for duration of implantation. The observed frequency of late and very late stent thrombosis was less in CoCr-EES (4%) versus SES (21%; P=0.029) and PES (26%; P=0.008). Neointimal thickness was comparable among the groups, whereas the percentage of uncovered struts was strikingly lower in CoCr-EES (median=2.6%) versus SES (18.0%; P<0.0005) and PES (18.7%; P<0.0005). CoCr-EES showed a lower inflammation score (with no hypersensitivity) and less fibrin deposition versus SES and PES. The observed frequency of neoatherosclerosis, however, did not differ significantly among the groups (CoCr-EES=29%; SES=35%; PES=19%). CoCr-EES had the least frequency of stent fracture (CoCr-EES=13%; SES=40%; PES=19%; P=0.007 for CoCr-EES versus SES), whereas fracture-related restenosis or thrombosis was comparable among the groups (CoCr-EES=6.5%; SES=5.5%; PES=1.2%).
  
  
  CONCLUSIONS
  CoCr-EES demonstrated greater strut coverage with less inflammation, less fibrin deposition, and less late and very late stent thrombosis compared with SES and PES in human autopsy analysis. Nevertheless, the observed frequencies of neoatherosclerosis and fracture-related adverse pathological events were comparable in these devices, indicating that careful long-term follow-up remains important even after CoCr-EES placement.
authors.affiliation: From CVPath Institute, Inc, Gaithersburg, MD (F.O., M.V., M.N., K.S., R.K., E.L., F.D.K., R.V.); Virginia Tech-Carilion School of Medicine, Roanoke, VA (J.F.); Partners Health Care Systems, Boston, MA (J.B.N.); and Emory University School of Medicine, Atlanta, GA (A.V.F.).
authors.forename: Fumiyuki
authors.initials: F
authors.lastname: Otsuka
authors.forename: Marc
authors.initials: M
authors.lastname: Vorpahl
authors.forename: Masataka
authors.initials: M
authors.lastname: Nakano
authors.forename: Jason
authors.initials: J
authors.lastname: Foerst
authors.forename: John B
authors.initials: JB
authors.lastname: Newell
authors.forename: Kenichi
authors.initials: K
authors.lastname: Sakakura
authors.forename: Robert
authors.initials: R
authors.lastname: Kutys
authors.forename: Elena
authors.initials: E
authors.lastname: Ladich
authors.forename: Aloke V
authors.initials: AV
authors.lastname: Finn
authors.forename: Frank D
authors.initials: FD
authors.lastname: Kolodgie
authors.forename: Renu
authors.initials: R
authors.lastname: Virmani
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001344:Autopsy; D001672:Biocompatible Materials; D002858:Chromium Alloys; D003324:Coronary Artery Disease / Q000473:pathology* / Q000628:therapy; D023903:Coronary Restenosis / Q000453:epidemiology / Q000473:pathology; D003328:Coronary Thrombosis / Q000453:epidemiology / Q000473:pathology; D003331:Coronary Vessels / Q000473:pathology*; D054855:Drug-Eluting Stents; D000068338:Everolimus; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D058426:Neointima / Q000473:pathology; D017239:Paclitaxel / Q000008:administration & dosage; D015995:Prevalence; D012042:Registries; D012189:Retrospective Studies; D020123:Sirolimus / Q000008:administration & dosage / Q000031:analogs & derivatives
chemical_list: D001672:Biocompatible Materials; D002858:Chromium Alloys; D007166:Immunosuppressive Agents; D000068338:Everolimus; D017239:Paclitaxel; D020123:Sirolimus
keywords: coronary restenosis; pathology; stents; thrombosis