Effects of ramiprilat-coated stents on neointimal hyperplasia, inflammation, and arterial healing in a porcine coronary restenosis model.
OBJECTIVE
The renin-angiotensin-aldosterone system has been implicated in the pathogenesis of neointimal hyperplasia, and a role for angiotensin II in the migration and proliferation of vascular smooth muscle cells in restenotic lesions has been proposed. The aim of this study was to determine the anti-proliferative and anti-inflammatory effects of ramiprilat-coated stents in a porcine coronary overstretch restenosis model.


METHODS
Pigs were randomized into two groups in which the coronary arteries {16 pigs (16 coronaries in each group)} had a 3.0×17 mm ramiprilat-coated MAC stent or a 3.0×17 mm control MAC stent (AMG, Munich, Germany) implanted with oversizing (stent-to-artery ratio, 1.3 : 1) in porcine coronary arteries, and histopathologic analysis was assessed 28 days after stenting.


RESULTS
There were no significant differences in the injury and inflammation scores between the two groups (1.20±0.43 vs. 1.23±0.57, p=0.8; and 1.21±0.39 vs. 1.25±0.49, p=0.6, respectively). Within the neointima, most inflammatory cells were lymphohistiocytes. Significant positive correlations existed between inflammatory cell counts and the neointima areas (r=0.567, p<0.001), and between inflammatory cell counts and the percent area stenosis (r=0.478, p<0.001). There was no significant difference in the inflammatory cell counts normalized to the injury (110±89 vs. 123±83, p=0.4) and fibrin scores (0.15±0.06 vs. 0.17±0.07, p=0.8) between the 2 groups. There were trends toward a smaller neointima area (1.06±0.51 mm(2) vs. 1.28±0.35 mm(2), p=0.083) and a smaller percent area stenosis (18.9±8.7% vs. 21.8±7.2%, p=0.088) in the ramiprilat-coated stent group.


CONCLUSIONS
Although the ramiprilat-coated stent did not show significant inhibitory effects on neointimal hyperplasia, the ramiprilat-coated stent showed good effects on the inflammatory reaction and arterial healing similar to the control stent in a porcine coronary restenosis model.
The Heart Center of Chonnam National University Hospital, Chonnam National University Research Institute of Medical Sciences, Gwangju, Korea.
Young Joon
YJ
Hong
Myung Ho
MH
Jeong
Sun-Jung
SJ
Song
Doo Sun
DS
Sim
Jung Ha
JH
Kim
Kyung Seob
KS
Lim
Daisuke
D
Hachinohe
Khurshid
K
Ahmed
Seung Hwan
SH
Hwang
Min Goo
MG
Lee
Jum Suk
JS
Ko
Keun-Ho
KH
Park
Hyun Ju
HJ
Yoon
Nam Sik
NS
Yoon
Kye Hun
KH
Kim
Hyung Wook
HW
Park
Ju Han
JH
Kim
Youngkeun
Y
Ahn
Jeong Gwan
JG
Cho
Dong Lyun
DL
Cho
Jong Chun
JC
Park
Jung Chaee
JC
Kang