OBJECTIVETo observe the safety and efficacy of early or non-early controlled-release arsenic-trioxide (As(2)O(3))-eluting stents on reducing in-stent neointimal hyperplasia.

METHODSBare stents, stents coated with polybutyl methacrylate/Nano silica (containing 200 microg of As(2)O(3) per stent or not), stents coated with polybutyl methacrylate/Nano silica inside (containing 200 microg of As(2)O(3) per stent or not) and poly-lactide-co-glycolide (PLGA) outside were deployed with mild oversizing in left anterior descending (LAD) and circumflex coronary arteries (LCX)of 30 canines (n = 6, 12 stents for each group).

RESULTSThe mean injury scores were similar in all groups at 4 weeks post stents implantation while the mean neointimal thickness, neointimal area and degree of stenosis were significantly reduced and the lumen area significantly increased in canines receiving single coating stents containing As(2)O(3) compared with single or double coating stents and bare stents groups (all P < 0.01). These effects were further enhanced in canines implanted with double coating stents containing As(2)O(3) (all P < 0.01 vs. single coating stents containing As(2)O(3)). No intraintimal hemorrhage, medial and adventitial necrosis, aneurysm, thrombosis, inflammatory cells infiltration were observed in all stenting groups.

CONCLUSIONSControlled-release As(2)O(3)-eluting stents resulted in a significant inhibition of neointimal hyperplasia in the canine coronary arteries 4 weeks after stents implantation and the effects is more significant with controlled-release of As(2)O(3) at non-early stage than that at early stage.