EFFECT OF NONANTICOAGULANT HEPARIN (ASTENOSE) ON RESTENOSIS AFTER BALLOON ANGIOPLASTY IN THE ATHEROSCLEROTIC RABBIT

PURPOSE: To determine whether intravenous administration of Astenose, a high-molecular-weight nonanticoagulant heparin, can reduce restenosi s following balloon angioplasty in a rabbit model. MATERIALS AND METHO DS: Focal atherosclerosis was induced in 54 rabbits (89 vessels), and angioplasty was performed after animals were randomized into five grou ps. Group 1 vessels (control) were treated with lactated Ringer soluti on for 28 days (n = 19); group 2, Astenose at 0.10 mg/kg per hour for 28 days (n = 16); group 3, Astenose at 0.33 mg/kg per hour for 28 days (n = 16); group 4, Astenose at 0.60 mg/kg per hour for 28 days (n = 1 7); and group 5, Astenose at 0.33 mg/kg per hour for 14 days (n = 21). Arteriograms were obtained to measure minimal luminal diameters befor e, immediately after, and 28 days after angioplasty, and the rabbits w ere killed for histologic analysis. RESULTS: Angiographically demonstr ated restenosis was significantly reduced in groups 3 (18.9% +/- 3.7, P = .04) and 4 (20.2% +/- 3.1, P = .04) compared with the control grou p (32.4% +/- 4.8). Group 5 showed a nonsignificant trend toward reduce d restenosis (23.1% +/- 2.9, P = .09), and group 2 showed restenosis s imilar to that in group 1 (31.0% +/- 2.5, P = .80). However, quantitat ive histopathologic analysis detected no differences among the groups in absolute plaque area, Medial area was significantly smaller in grou ps 2 and 5 (P less than or equal to .002) than in group 1, and there w as a nonsignificant trend toward reduced medial area in groups 3 and 4 (P = .12). CONCLUSION: Long-term intravenous Astenose therapy resulte d in a modest but statistically significant reduction in angiographica lly demonstrated restenosis after angioplasty in this atherosclerotic rabbit model.