Impact of heterogeneous overlapping drug-eluting stents on the arterial responses of rabbit iliac arteries: a comparison with overlapping bare metal stents.
OBJECTIVE
Although the use of heterogeneous overlapping drug-eluting stents (DES) is not uncommon in clinical practice, whether the implantation sequences of heterogeneous DES will influence the endothelialization or arterial responses differently remains unclear.


METHODS
Twenty-one rabbits were randomized to receive overlapping stents in the iliac artery for 3 months {distal sirolimus-eluting stent (SES, Cypher™)+proximal paclitaxel-eluting stent (PES, Taxus™) (C+T, n=7), distal Taxus+proximal Cypher (T+C, n=7) and bare metal stent (BMS)+BMS (B+B, n=7)}. Endothelial function was evaluated by the acetylcholine provocation test during follow-up angiography. Histopathological changes in proximal, overlapped, and distal stented segments were evaluated.


RESULTS
Although the overall angiographic outcomes were comparable, late loss (mm) in the distal stented segment was higher in the B+B (0.39±0.07) and C+T (0.40±0.20) than that in the T+C (0.06±0.02) group (p<0.001). The incidence of acetylcholine-induced spasm was higher in the DES groups compared with BMS, regardless of the implantation sequences (85.7% in C+T vs. 14.3% in B+B vs. 71.4% in T+C, p=0.017). Notably, only the distal Cypher implantation group (C+T) had three cases of stent fracture. A histopathological analysis showed that despite similar arterial injury scores, Taxus and Cypher stents had higher inflammatory reactions at the overlapped and distal segments compared with those of BMS.


CONCLUSIONS
Despite similar arterial injury, higher inflammatory reactions were observed in overlapping DES segments regardless of the implantation sequence compared with that of BMS. Moreover, DES was associated with impaired endothelial function on the adjacent non-stented segments.
Cardiovascular Center, Korea University Guro Hospital, Seoul, Korea.
Seung-Woon
SW
Rha
Kang-Yin
KY
Chen
Dong Joo
DJ
Oh
Yong-Jian
YJ
Li
Zhe
Z
Jin
Kanhaiya Lal
KL
Poddar
Sureshkumar
S
Ramasamy
Yoshiyasu
Y
Minami
Amro
A
Elnagar
Byoung Geol
BG
Choi
Sang Pyo
SP
Hong
Byoung Won
BW
Cheon
Sang Ki
SK
Moon
Sung Il
SI
Im
Sun Won
SW
Kim
Jin Oh
JO
Na
Cheol Ung
CU
Choi
Hong Euy
HE
Lim
Jin Won
JW
Kim
Eung Ju
EJ
Kim
Seong Woo
SW
Han
Chang Gyu
CG
Park
Hong Seog
HS
Seo
Jung Ha
JH
Kim
Young Joon
YJ
Hong
Myung Ho
MH
Jeong