Inhibition of neointimal hyperplasia with a novel zotarolimus coated balloon catheter.

BACKGROUND: Non stent based delivery of antiproliferative agents using drug coated balloon catheters may offer additional flexibility and efficacy in a broad range of applications. The lipophilic antiproliferative drug zotarolimus makes it a potential candidate for balloon delivery. The aim of the present study was to evaluate the safety and efficacy of a prototype zotarolimus coated balloon (ZCB) catheter in comparison to a zotarolimus eluting stent (ZES) in the porcine coronary overstretch model. METHODS: Eighty-four stents (diameters 3.0 and 3.5 mm; length 15 mm) were implanted in LAD and Cx of 42 domestic pigs: control (TriMaxx, Abbott, polymer coated stent without drug, implanted with uncoated PCI catheter, n = 56); ZES (ZoMaxx, Abbott, stent coated with zotarolimus in polymer, implanted with uncoated PCI catheter, n = 14); ZCB (TriMaxx, Abbott, polymer coated stent without drug, implanted with zotarolimus coated PCI catheter, n = 14). Drug content of the vessel wall (n = 9) was measured about 10-30 min post intervention with ZCB in additional pigs. RESULTS: Immediately after ZCB treatment 101 ± 31 µg of zotarolimus was detected in the coronary arteries. After 28 days ZES led to a reduction of neointimal area from 4.32 ± 1.45 to 3.32 ± 1.11 mm2 (P = 0.019 vs. control). The effect of neointimal inhibition was more pronounced with the novel ZCB (2.79 ± 1.43 mm², P = 0.001 vs. control). Inflammation score was significantly reduced in vessels treated with the ZCB (0.75 ± 0.86 compared to control (1.45 ± 0.94, P = 0.013) and ZES (1.65 ± 0.90, P = 0.012). CONCLUSION: Zotarolimus coated balloons and stents were found to effectively reduce neointimal proliferation in the porcine coronary model. Inflammation scores were significantly reduced after treatment with the coated balloon. Zotarolimus balloon coating might be a novel option in preventing and treating restenosis.

Zotarolimus-eluting stents reduce experimental coronary artery neointimal hyperplasia after 4 weeks.

AIMS: The addition of drug elution to coronary stents plays an integral role in coronary restenosis prevention. The present study was undertaken to determine the mechanism of action and the in vitro and in vivo efficacy of zotarolimus, a new chemical entity designed specifically for elution from phosphorylcholine (PC)-coated stents, for the reduction of neointimal hyperplasia in porcine coronary arteries. METHODS AND RESULTS: In vitro studies of Zotarolimus bound to FKBP-12 potently inhibited smooth muscle cells (SMCs) and endothelial cell (EC) proliferation. Twenty PC-only and 20 stents eluting zotarolimus 10 microg/mm were implanted in the coronary arteries of 20 domestic juvenile swine. After 28 days, zotarolimus stents exhibited less area stenosis (22.4+/-8.6 vs. 35.7+/-13%, P = 0.01), less neointimal area (1.69+/-0.55 vs. 2.78+/-1.07 mm(2), P = 0.01), less neointimal thickness (0.25+/-0.07 vs. 0.38+/-0.13 mm, P = 0.01), and greater lumen area (6.07+/-1.39 vs. 5.02+/-1.3 mm2, P = 0.01). All arteries in both the polymer-only and polymer/drug stent showed near-complete healing and minimal toxicity. Zotarolimus did not affect the extrastent segments nor alter the overall artery size (external elastic lamina cross-sectional area 9.18+/-1.19 vs. 9.06+/-1.28 mm2, P = 0.7). CONCLUSION: Zotarolimus binds to FKBP-12 and in vitro inhibits SMC and EC proliferation. Zotarolimus applied to PC-coated stents reduces neointima in the swine coronary model after 28 days. These results suggest potentially promising human clinical application for coronary stenting with this polymer/drug combination.