Incomplete neointimal coverage of sirolimus-eluting stents: angioscopic findings.
OBJECTIVE
The goal of this study was to use angioscopy to investigate the amount of neointimal coverage after sirolimus-eluting stent (SES) implantation.


BACKGROUND
Sirolimus-eluting stents reduce intimal hyperplasia.


METHODS
We used angioscopy to evaluate 37 consecutive stented coronary artery lesions (15 SES and 22 bare-metal stents [BMS]) in 25 patients (18 men, 7 women) at 3 to 6 months after stent implantation. Angioscopic evaluation focused on: 1) neointimal coverage of stent struts, and 2) the existence of thrombi. The degree of neointimal coverage was classified as grade 0 when there was no neointimal coverage (similar to immediately after the implantation); grade 1 when stent struts bulged into the lumen, but were covered and still translucently visible; grade 2 when stent struts were visible but not clearly seen (not translucent); and grade 3 when stent struts were not visible because they were embedded in the neointima.


RESULTS
Thrombi were identified in eight stented segments, tended to be more common with SES (p = 0.14), but were not seen on angiography. Three of the 15 SES (20%) had grade 0 neointimal coverage, and only 2 SES (13.3%) had complete coverage (grades 2/3). In contrast, all 22 BMS showed complete intimal coverage (grades 2/3). Thrombi were more common in stents with incomplete neointimal coverage (p = 0.09).


CONCLUSIONS
The SES had incomplete neointimal coverage three to six months after implantation, and this was associated with subclinical thrombus formation.
Kotani
Jun-ichi
J
Cardiovascular Division, Kansai Rosai Hospital, Amagasaki, Japan. shamallv8@aol.com
Awata
Masaki
M
Nanto
Shinsuke
S
Uematsu
Masaaki
M
Oshima
Fusako
F
Minamiguchi
Hitoshi
H
Mintz
Gary S
GS
Nagata
Seiki
S
D000368:Aged; D017546:Angioscopy; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects; D017023:Coronary Angiography; D023903:Coronary Restenosis / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control; D023921:Coronary Stenosis / Q000628:therapy; D003328:Coronary Thrombosis / Q000175:diagnosis* / Q000209:etiology / Q000517:prevention & control; D003692:Delayed-Action Preparations; D005260:Female; D006801:Humans; D006965:Hyperplasia; D007166:Immunosuppressive Agents / Q000008:administration & dosage* / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D020123:Sirolimus / Q000008:administration & dosage* / Q000009:adverse effects; D015607:Stents / Q000009:adverse effects*; D017539:Tunica Intima / Q000187:drug effects* / Q000473:pathology; D014945:Wound Healing / Q000187:drug effects
D003692:Delayed-Action Preparations; D007166:Immunosuppressive Agents; D020123:Sirolimus