Single-dose intramuscular administration of sustained-release Angiopeptin reduces neointimal hyperplasia in a porcine coronary in-stent restenosis model

First human experience with angiopeptin-eluting stent: a quantitative coronary angiography and three-dimensional intravascular ultrasound study

Angiopeptin has been shown to reduce in-stent restenosis in various animal models. Meanwhile, BiodivYsio DD phosphorylcholine (PC)-coated stent provides a platform for local delivery of antiproliferative agents to the coronary artery. We studied the feasibility, safety, and impact on tissue growth of angiopeptin-eluting BiodivYsio DD PC-coated stents in human native de novo coronary lesions. We enrolled 14 patients (16 lesions) who underwent intravascular ultrasound (IVUS)-guided angiopeptin-eluting stent implantation in native coronary arteries between 3.0 and 4.0 mm in diameter with lesion length<or=18 mm. We successfully implanted 13 stents loaded with 22 microg of angiopeptin and three stents with 126 microg of angiopeptin. No major adverse cardiac events or target vessel failure occurred at 1-year clinical follow-up. All patients underwent 6-month angiographic and volumetric IVUS follow-up. In-stent late loss was 0.46+/-0.32 mm in the low-dose group and 0.26+/-0.14 mm in the high-dose group. Binary restenosis rate was 0%. Follow-up percentage neointimal hyperplasia by IVUS was 18.4%+/-22.5% for the low-dose group and 10.2%+/-5.8% for the high-dose group, respectively. There were no edge effect and late stent malapposition. Angiopeptin-eluting BiodivYsio DD PC stent appears feasible and safe in treating native de novo coronary lesions with modest degree of neointimal hyperplasia.

Pharmacological treatment for prevention of restenosis

Coronary artery disease (CAD) is the leading cause of mortality and morbidity among adults in the Western world. Coronary artery bypass grafting and percutaneous coronary interventions (PCI) have gained widespread acceptance for the treatment of symptomatic CAD. There has been an explosive growth worldwide in the utilisation of PCI, such as balloon angioplasty and stenting, which now accounts for over 50% of coronary revascularisation. Despite the popularity of PCI, the problem of recurrent narrowing of the dilated artery (restenosis) continues to vex investigators. In recent years, significant advances have occurred in the understanding of restenosis. Two processes seem to contribute to restenosis: remodelling (vessel size changes) and intimal hyperplasia (vascular smooth muscle cell [VSMC] proliferation and extracellular matrix [ECM] deposition). Despite considerable efforts, pharmacological approaches to decrease restenosis have been largely unsuccessful and the only currently applied modality to reduce the restenosis rate is stenting. However, stenting only prevents remodelling and does not inhibit intimal hyperplasia. Several potential targets for inhibiting restenosis are currently under investigation including platelet activation, the coagulation cascade, VSMC proliferation and migration, and ECM synthesis. In addition, new approaches for local drug therapy, such as drug eluting stents, are currently being evaluated in preclinical and clinical studies. In this article, we critically review the current status of drugs that are being evaluated for restenosis at various stages of development (in vitro, preclinical animal models and human trials).

Paclitaxel-coated Gianturco-Roubin II (GR II) stents reduce neointimal hyperplasia in a porcine coronary in-stent restenosis model

BACKGROUND

Drug-coated stents may treat both mechanisms of restenosis, namely, geometric remodeling and neointimal hyperplasia. Paclitaxel, an antimicrotubule agent, has been shown to inhibit smooth muscle cell proliferation and migration, and may be an excellent candidate for local elution from a stent platform.

METHODS

To study the antirestenosis effects of drug-coated stents, we impregnated paclitaxel (175-200 microg/stent with programmed elution over 6 months) on Gianturco-Roubin II (GR II) stents. These stents and control stents without drugs were implanted in porcine coronary arteries (stent/artery approx. 1.1) and evaluated 4 weeks later.

RESULTS

The vessel size and the stent-to-artery ratio were similar between the groups. However, at 4 weeks, the paclitaxel group had significantly reduced in-stent restenosis compared with the controls (51 +/- 27 versus 27 +/- 27% diameter stenosis, P < 0.05 and 669 +/- 357 versus 403 +/- 197 microm neointimal thickness, P < 0.05). This study further confirmed the biocompatibility of the polymer, with no foreign body reaction in any of the groups.

CONCLUSIONS

This study shows that the paclitaxel-coated stents significantly reduced in-stent restenosis without eliciting inflammation.