Examination of anti-intima hyperplastic effect on cilostazol-eluting stent in a porcine model.

Background. Current drug-eluting stents (DES) have shown a reduction in neointimal hyperplasia and restenosis. However, the aggressive use of DES has an untoward side effect known as DES thrombosis. To overcome this unfavorable effect, other drug candidates are currently being studied. Cilostazol is known to inhibit intimal proliferation and accelerate endothelialization. These beneficial properties suggest that the drug could be a DES candidate. Methods. Twelve juvenile swine were randomly assigned to two groups receiving either cilostazol-eluting stents (CES) or bare-metal stents (BMS). All except 1 in the BMS group received follow-up angiography and were sacrificed at day-28 for histopathological analysis. Results. A similar inflammatory response to stenting was observed in both groups on histopathological analysis. No significant difference was observed in the injury score between the groups, suggesting that the drug and PEA polymer were not associated with inflammation. There was a 23% reduction in intimal area in the CES group compared with the BMS group (1.58 ± 0.8 mm 2 vs. 2.05 ± 0.82 mm 2 for cilostazol vs. bare metal, respectively; p = 0.04). Late loss was also significantly lower in the CES group than in the BMS group (0.82 ± 0.81 mm vs. 1.86 ± 1.04 mm, respectively; p = 0.0296). Conclusion. The present study demonstrated that CES suppressed intimal hyperplasia and reduced intimal late loss. Pleiotropic effects of cilostazol such as the suppression of restenosis and the acceleration of endothelialization demonstrated in systemic delivery can also be expected in local delivery.