Localized hypersensitivity and late coronary thrombosis secondary to a sirolimus-eluting stent: should we be cautious?
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.
Virmani
Renu
R
Department of Cardiovascular Pathology, Armed Forces Institute of Pathology, 6825 16th St NW, Washington, DC, USA. virmani@afip.osd.mil
Guagliumi
Giulio
G
Farb
Andrew
A
Musumeci
Giuseppe
G
Grieco
Niccolo
N
Motta
Teresio
T
Mihalcsik
Laurian
L
Tespili
Maurizio
M
Valsecchi
Orazio
O
Kolodgie
Frank D
FD
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
D020123:Sirolimus