Objective: To assess the efficacy of Mytrolimus (CCI-779), a derivative of rapamycin, eluting stents in preventing restenosis in the porcine model.
Methods: The bare stents (n = 10), stents coated with polyolefin (n = 10) or stents coated with Mytrolimus (160 microg/18 mm) in polyolefin (n = 8) were implanted in left anterior descending coronary arteries or right coronary artery of mini-swine. Coronary angiography was performed after 4 weeks then the animals were sacrificed. The cross sections of the stented coronary arteries were analyzed, the injury score, luminal area, neointimal thickness above the struts and between the struts of stents, neointimal area and percentage of restenosis were measured.
Results: The mean injury scores and luminal area were similar in three groups. There was no difference in above-stated items between the polyolefin coating stent and bare mental stent. To compare Mytrolimus-eluting stent with bare-stent, neointimal thickness above the struts [(0.18 +/- 0.08) mm vs (0.33 +/- 0.25) mm, P < 0.05] and between the struts [(0.14 +/- 0.05) mm vs (0.28 +/- 0.23) mm, P < 0.05] and neointimal area [(1.09 +/- 0.24) mm(2) vs (2.44 +/- 1.59) mm(2), P < 0.05] were significantly decreased in the Mytrolimus-eluting stent group than in bare mental stent group. Compared with bare-stent, the Mytrolimus eluting stent was associated with a 55.33% reduction in neointimal area. No restenosis developed in the Mytrolimus group.
Conclusion: The Mytrolimus-eluting stents can effectively inhibit the neointimal hyperplasia in stented areas of coronary arteries 4 weeks after stent implantation in porcine model.