Difference in neointimal appearance between early and late restenosis after sirolimus-eluting stent implantation assessed by optical coherence tomography.
OBJECTIVE
Late in-stent restenosis (ISR) is an important clinical issue in the drug-eluting stent era. Autopsy studies have reported different underlying mechanisms between early ISR and late ISR. The aim of the present study was to compare the neointimal tissue appearance between early ISR (<1 year) and late ISR (>1 year) after sirolimus-eluting stent (SES) implantation using optical coherence tomography (OCT).


METHODS
We examined the neointimal tissue appearance in 48 ISR lesions after SES implantation [30 early ISR lesions (8±1 months after stenting) and 18 late ISR lesions (34±14 months after stenting)] by OCT. ISR was defined as percent diameter stenosis more than 50% within the stented segment in angiography. Lipid-rich neointima was characterized by signal-poor regions with diffuse borders. Thin-cap fibroatheroma (TCFA)-like neointima was defined by lipid-rich neointima with cap thickness 65 μm or less.


RESULTS
In the OCT findings, heterogeneous neointima was more often observed in the late ISR group compared with the early ISR group (89 vs. 43%, P=0.002). Although the frequency of intraluminal thrombus was not different between the two groups (P=0.085), the frequency of lipid-rich neointima (83 vs. 27%, P<0.001), TCFA-like neointima (39 vs. 10%, P=0.028), microchannels within neointima (67 vs. 27%, P=0.007), and neointimal disruption (33 vs. 3%, P=0.008) was significantly higher in the late ISR group.


CONCLUSIONS
In the present OCT study, it was found that atherosclerotic progression of neointima, such as lipid-rich neointima, TCFA-like neointima, microchannels, and neointimal disruption, was more often observed in late ISR lesions after SES implantation compared with early ISR ones.
Department of Cardiovascular Medicine, Wakayama Medical University, Wakayama, Japan.
Yasushi
Y
Ino
Takashi
T
Kubo
Hironori
H
Kitabata
Kohei
K
Ishibashi
Takashi
T
Tanimoto
Yoshiki
Y
Matsuo
Kunihiro
K
Shimamura
Yasutsugu
Y
Shiono
Makoto
M
Orii
Kenichi
K
Komukai
Takashi
T
Yamano
Tomoyuki
T
Yamaguchi
Kumiko
K
Hirata
Atsushi
A
Tanaka
Masato
M
Mizukoshi
Toshio
T
Imanishi
Takashi
T
Akasaka
D000368:Aged; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000473:pathology / Q000628:therapy; D023903:Coronary Restenosis / Q000473:pathology*; D003331:Coronary Vessels / Q000473:pathology*; D018450:Disease Progression; D054855:Drug-Eluting Stents; D005260:Female; D006801:Humans; D008055:Lipids / Q000032:analysis; D008297:Male; D058426:Neointima / Q000473:pathology*; D020123:Sirolimus / Q000008:administration & dosage; D013997:Time Factors; D041623:Tomography, Optical Coherence
D008055:Lipids; D020123:Sirolimus