Serial long-term evaluation of neointimal stent coverage and thrombus after sirolimus-eluting stent implantation by use of coronary angioscopy.
OBJECTIVE
Progression of neointimal stent coverage (NSC) and changes in thrombus were evaluated serially by coronary angioscopy for up to 2 years after sirolimus-eluting stent (SES) implantation.


METHODS
Serial angioscopic observations were performed in 20 segments of 20 patients at baseline, at 6 months and at 2 years after SES implantation. NSC was classified as follows: 0, uncovered struts; 1, visible struts through thin neointima; or 2, no visible struts. In each patient, maximum and minimum NSC was evaluated. Existence of thrombus was also examined.


RESULTS
The maximum NSC increased from 6 months to 2 years (mean (SD) 1.2 (0.4) vs 1.8 (0.4), respectively, p = 0.005), while the minimum NSC did not change (0.7 (0.5) vs 0.8 (0.4), respectively, p = 0.25). The prevalence of patients with uncovered struts did not decrease from 6 months to 2 years (35% vs 20%, respectively, p = 0.29). Although there were no thrombus-related adverse events, new thrombus formation was found in 5% of 6-month, and in 20% of 2-year follow-up evaluations. The prevalence of thrombus inside the SES at baseline, 6 months and 2 years was similar (40%, 40% and 30%, respectively; p = NS).


CONCLUSIONS
Neointimal growth inside the SES progressed heterogeneously. Uncovered struts persisted in 20% of the patients for up to 2 years and subclinical thrombus formation was not uncommon.
Takano
Masamichi
M
Department of Internal Medicine, Chiba-Hokusoh Hospital, Nippon Medical School, 1715 Kamakari, Imba, Chiba, 270-1694, Japan. takanom@nms.ac.jp
Yamamoto
Masanori
M
Xie
Yong
Y
Murakami
Daisuke
D
Inami
Shigenobu
S
Okamatsu
Kentaro
K
Seimiya
Koji
K
Ohba
Takayoshi
T
Seino
Yoshihiko
Y
Mizuno
Kyoichi
K
D000368:Aged; D017546:Angioscopy; D023903:Coronary Restenosis / Q000175:diagnosis / Q000209:etiology; D023921:Coronary Stenosis / Q000628:therapy; D003328:Coronary Thrombosis / Q000175:diagnosis / Q000209:etiology*; D054855:Drug-Eluting Stents; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D020123:Sirolimus / Q000008:administration & dosage*; D017539:Tunica Intima / Q000473:pathology*
D007166:Immunosuppressive Agents; D020123:Sirolimus