Abstract 3045: Angioscopic Assessment whether Neointimal Formation Occur or not After Sirolimus-Eluting Stent Implantation (after 1, 3, 6, 12 months study)
The aim of this study is to observe the surface of sirolimus-eluting stent (SES) by angioscopy whether or not stent surface neointimal formation over the stent surface occur 1, 3, 6, 12 months after stent implantation. In addition, we also assessed thrombus formation at the stent site. We performed angioscopy to 36 patients 42 lesions after SES implantation. 25 males, 11 females, mean age was 71Â ±8 years old. All patients received double anti-platelet therapy 1 week before stent implantation to follow up examination. The extent of neointimal stent coverage was semiquantitatively evaluated using a 4-point grading system: 0=complete exposure of stent struts; 1=dull light reflex from stent struts; 2=no light reflex but slightly visible stent struts; 3=complete coverage without vision of the stent struts. We defined that over grade 1 stent coverage score had a neointimal formation. Thrombus formation was classified as follows; none, WT (white thrombus dominant), RT (red thrombus dominant), MT (mixed thrombus or same amount of WT and RT). Rate of neointimal formation at 1, 3, 6, 12 months after stent implantation was 42%, 33%, 57% and 92%. Rate of thrombus formation immediately, 1, 3, 6 and 12 months after PCI was 35%, 71%, 67%, 86%, and 100%. RT existed immediately after PCI but it was decreased in progress of time and WT mainly existed 6 and 12 months after stent implantation These observations indicated that neointimal coverage 12 months after SES implantation was almost achived, however, it is difficult to discontinue anti-platelet therapy because of the existence of thrombus.