title: Localized hypersensitivity and late coronary thrombosis secondary to a sirolimus-eluting stent: should we be cautious?
abstract: BACKGROUND
  The US Food and Drug Administration recently issued a warning of subacute thrombosis and hypersensitivity reactions to sirolimus-eluting stents (Cypher). The cause and incidence of these events have not been determined.
  
  
  RESULTS
  We present findings of a 58-year-old man who died of late stent thrombosis 18 months after receiving 2 Cypher stents for unstable angina. Although angiographic and intravascular ultrasound results at 8 months demonstrated the absence of neointimal formation, vessel enlargement was present. An autopsy showed aneurysmal dilation of the stented arterial segments with a severe localized hypersensitivity reaction consisting predominantly of T lymphocytes and eosinophils.
  
  
  CONCLUSIONS
  The known pharmacokinetic elution profile of Cypher stents and the presence of polymer fragments surrounded by giant cells and eosinophils suggest that a reaction to the polymer may have caused late stent thrombosis. Careful long-term follow-up of patients with vessel enlargement after Cypher stent placement is recommended.
authors.affiliation: Department of Cardiovascular Pathology, Armed Forces Institute of Pathology, 6825 16th St NW, Washington, DC, USA. virmani@afip.osd.mil
authors.forename: Renu
authors.initials: R
authors.lastname: Virmani
authors.forename: Giulio
authors.initials: G
authors.lastname: Guagliumi
authors.forename: Andrew
authors.initials: A
authors.lastname: Farb
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Musumeci
authors.forename: Niccolo
authors.initials: N
authors.lastname: Grieco
authors.forename: Teresio
authors.initials: T
authors.lastname: Motta
authors.forename: Laurian
authors.initials: L
authors.lastname: Mihalcsik
authors.forename: Maurizio
authors.initials: M
authors.lastname: Tespili
authors.forename: Orazio
authors.initials: O
authors.lastname: Valsecchi
authors.forename: Frank D
authors.initials: FD
authors.lastname: Kolodgie
mesh_terms: D000789:Angina, Unstable / Q000000981:diagnostic imaging / Q000628:therapy; D017023:Coronary Angiography; D003328:Coronary Thrombosis / Q000209:etiology* / Q000473:pathology; D016503:Drug Delivery Systems / Q000009:adverse effects*; D017809:Fatal Outcome; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000473:pathology; D020123:Sirolimus / Q000008:administration & dosage* / Q000627:therapeutic use; D015607:Stents / Q000009:adverse effects*; D014463:Ultrasonography
chemical_list: D020123:Sirolimus