Delayed neointimalization on sirolimus-eluting stents: 6-month and 12-month follow up by optical coherence tomography.
BACKGROUND
Sirolimus-eluting stents (SES) have incomplete neointimal coverage at 6-month follow up as determined with optical coherence tomography (OCT). The long-term detailed changes of neointima in SES remains to be clarified.


RESULTS
Serial changes in neointimal coverage of SES from 6 months to 12 months using OCT were examined. Of 21 SES in 13 patients, OCT was used to visualize 2,321 stent struts at 6 months and 2,285 stent struts at 12 months. The frequency of struts without neointimal coverage decreased from 6 months to 12 months (from 10.4 to 5.7%). The frequency of malapposed struts decreased from 6 months to 12 months (from 1.7 to 0.2%). The average thickness of the neointima increased (from 112 +/-123 to 120 +/-130 microm). The frequency of struts located at the side branch orifice without neointima decreased (from 4 out of 17 (24%) to 0 out of 17 (0%)). Complete coverage with neointima was observed in 14% (3 of 21 SES) at 6 months, and 24% (5 of 21 SES) at 12 months.


CONCLUSIONS
Additional neointimal coverage was observed between 6 and 12 months, with a small increase in the neointimal thickness. The incidence of complete coverage, however, was still low at 12 months. These findings suggest delayed neointimalization on SES.
Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine.
Hiroki
H
Katoh
Junya
J
Shite
Toshiro
T
Shinke
Daisuke
D
Matsumoto
Yusuke
Y
Tanino
Daisuke
D
Ogasawara
Takahiro
T
Sawada
Naoki
N
Miyoshi
Hiroyuki
H
Kawamori
Naoki
N
Yoshino
Ken-ichi
K
Hirata
D000368:Aged; D003328:Coronary Thrombosis / Q000453:epidemiology / Q000503:physiopathology; D003331:Coronary Vessels / Q000473:pathology / Q000503:physiopathology*; D054855:Drug-Eluting Stents; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000175:diagnosis* / Q000503:physiopathology*; D012307:Risk Factors; D020123:Sirolimus; D013997:Time Factors; D041623:Tomography, Optical Coherence; D017539:Tunica Intima / Q000473:pathology / Q000503:physiopathology*
D020123:Sirolimus