Preventive effects of the heparin-coated stent on restenosis in the porcine model.

The coronary stent reduces acute coronary arterial occlusion and late restenosis during and after coronary intervention. However, stent thrombosis and restenosis are still major limitations in the widespread use of the coronary stent. Local drug delivery using the heparin-coated stent may be a new approach, which reduces the incidence of stent thrombosis and restenosis. In order to evaluate the effects of the heparin-coated stent on stent restenosis, heparin-coated stents were compared with control stents in a porcine coronary stent restenosis model. Stent overdilation injury (stent:artery = 1.3:1.0) was performed with bare Wiktor stents (group I, n = 10) and heparin-coated Wiktor stents (group II, n = 20; HEPAMED, Medtronics) in porcine coronary arteries. Follow-up quantitative coronary angiography (QCA) was performed at 4 weeks after stenting, and histo-pathologic assessments of stented porcine coronary arteries were compared in both groups. On QCA, percent diameter stenosis was significantly higher in group I than in group II (16.3% +/- 6.62% vs. 9.6% +/- 5.06%, P < 0.05). The injury score of stented porcine coronary arteries was the same in both groups (1. 26 +/- 0.23 vs. 1.20 +/- 0.22). The area of pathologic stenosis of the stented arteries was higher in group I than in group II (41.6% +/- 12.5% vs. 27.1% +/- 9.9%, P < 0.005). The neointimal area was higher in group I than in group II (4.58 +/- 1.41 mm(2) vs. 2.57 +/- 1.07 mm(2), P < 0.05). By immunohistochemistry, the proliferating cell nuclear antigen (PCNA) index was higher in group I compared with group II (11.2% +/- 6.75% vs. 6.3% +/- 4.14%, P < 0.05). The heparin-coated stent is effective in the prevention of late coronary stent restenosis in a porcine coronary stent restenosis model. This may be related to the inhibition of neointimal cell proliferation. Copyright 1999 Wiley-Liss, Inc.